Commit Graph

376 Commits

Author SHA1 Message Date
Jerome Brunet
04bf9ab335 clk: fix determine rate error with pass-through clock
If we try to determine the rate of a pass-through clock (a clock which
does not implement .round_rate() nor .determine_rate()),
clk_core_round_rate_nolock() will directly forward the call to the
parent clock. In the particular case where the pass-through actually
does not have a parent, clk_core_round_rate_nolock() will directly
return 0 with the requested rate still set to the initial request
structure. This is interpreted as if the rate could be exactly achieved
while it actually cannot be adjusted.

This become a real problem when this particular pass-through clock is
the parent of a mux with the flag CLK_SET_RATE_PARENT set. The
pass-through clock will always report an exact match, get picked and
finally error when the rate is actually getting set.

This is fixed by setting the rate inside the req to 0 when core is NULL
in clk_core_round_rate_nolock() (same as in __clk_determine_rate() when
hw is NULL)

Fixes: 0f6cc2b8e9 ("clk: rework calls to round and determine rate callbacks")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-03-12 15:10:22 -07:00
Jerome Brunet
99652a469d clk: migrate the count of orphaned clocks at init
The orphan clocks reparents should migrate any existing count from the
orphan clock to its new acestor clocks, otherwise we may have
inconsistent counts in the tree and end-up with gated critical clocks

Assuming we have two clocks, A and B.
* Clock A has CLK_IS_CRITICAL flag set.
* Clock B is an ancestor of A which can gate. Clock B gate is left
  enabled by the bootloader.

Step 1: Clock A is registered. Since it is a critical clock, it is
enabled. The clock being still an orphan, no parent are enabled.

Step 2: Clock B is registered and reparented to clock A (potentially
through several other clocks). We are now in situation where the enable
count of clock A is 1 while the enable count of its ancestors is 0, which
is not good.

Step 3: in lateinit, clk_disable_unused() is called, the enable_count of
clock B being 0, clock B is gated and and critical clock A actually gets
disabled.

This situation was found while adding fdiv_clk gates to the meson8b
platform.  These clocks parent clk81 critical clock, which is the mother
of all peripheral clocks in this system. Because of the issue described
here, the system is crashing when clk_disable_unused() is called.

The situation is solved by reverting
commit f8f8f1d044 ("clk: Don't touch hardware when reparenting during registration").
To avoid breaking again the situation described in this commit
description, enabling critical clock should be done before walking the
orphan list. This way, a parent critical clock may not be accidentally
disabled due to the CLK_OPS_PARENT_ENABLE mechanism.

Fixes: f8f8f1d044 ("clk: Don't touch hardware when reparenting during registration")
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2018-03-12 11:10:47 -07:00
Shawn Lin
7f95beea36 clk: update cached phase to respect the fact when setting phase
It's found that the final phase set by driver doesn't match that of
the output from clk_summary:

dwmmc_rockchip fe310000.dwmmc: Successfully tuned phase to 346
mmc0: new ultra high speed SDR104 SDIO card at address 0001

cat /sys/kernel/debug/clk/clk_summary | grep sdio_sample
sdio_sample	0        1        0    50000000 0 0

It seems the cached core->phase isn't updated after the clk was
registered. So fix this issue by updating the core->phase if setting
phase successfully.

Fixes: 9e4d04adeb ("clk: add clk_core_set_phase_nolock function")
Cc: Stable <stable@vger.kernel.org>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2018-03-11 18:21:19 -07:00
Linus Torvalds
3879ae653a The core framework has a handful of patches this time around, mostly due
to the clk rate protection support added by Jerome Brunet. This feature
 will allow consumers to lock in a certain rate on the output of a clk so
 that things like audio playback don't hear pops when the clk frequency
 changes due to shared parent clks changing rates. Currently the clk
 API doesn't guarantee the rate of a clk stays at the rate you request
 after clk_set_rate() is called, so this new API will allow drivers
 to express that requirement. Beyond this, the core got some debugfs
 pretty printing patches and a couple minor non-critical fixes.
 
 Looking outside of the core framework diff we have some new driver
 additions and the removal of a legacy TI clk driver. Both of these hit
 high in the dirstat. Also, the removal of the asm-generic/clkdev.h file
 causes small one-liners in all the architecture Kbuild files. Overall, the
 driver diff seems to be the normal stuff that comes all the time to
 fix little problems here and there and to support new hardware.
 
 Core:
  - Clk rate protection
  - Symbolic clk flags in debugfs output
  - Clk registration enabled clks while doing bookkeeping updates
 
 New Drivers:
  - Spreadtrum SC9860
  - HiSilicon hi3660 stub
  - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
  - Amlogic Meson-AXG
  - ASPEED BMC
 
 Removed Drivers:
  - TI OMAP 3xxx legacy clk (non-DT) support
  - asm*/clkdev.h got removed (not really a driver)
 
 Updates:
  - Renesas FDP1-0 module clock on R-Car M3-W
  - Renesas LVDS module clock on R-Car V3M
  - Misc fixes to pr_err() prints
  - Qualcomm MSM8916 audio fixes
  - Qualcomm IPQ8074 rounded out support for more peripherals
  - Qualcomm Alpha PLL variants
  - Divider code was using container_of() on bad pointers
  - Allwinner DE2 clks on H3
  - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
  - Mediatek clk driver compile test support
  - AT91 PMC clk suspend/resume restoration support
  - PLL issues fixed on si5351
  - Broadcom IProc PLL calculation updates
  - DVFS support for Armada mvebu CPU clks
  - Allwinner fixed post-divider support
  - TI clkctrl fixes and support for newer SoCs
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Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

Pull clk updates from Stephen Boyd:
 "The core framework has a handful of patches this time around, mostly
  due to the clk rate protection support added by Jerome Brunet.

  This feature will allow consumers to lock in a certain rate on the
  output of a clk so that things like audio playback don't hear pops
  when the clk frequency changes due to shared parent clks changing
  rates. Currently the clk API doesn't guarantee the rate of a clk stays
  at the rate you request after clk_set_rate() is called, so this new
  API will allow drivers to express that requirement.

  Beyond this, the core got some debugfs pretty printing patches and a
  couple minor non-critical fixes.

  Looking outside of the core framework diff we have some new driver
  additions and the removal of a legacy TI clk driver. Both of these hit
  high in the dirstat. Also, the removal of the asm-generic/clkdev.h
  file causes small one-liners in all the architecture Kbuild files.

  Overall, the driver diff seems to be the normal stuff that comes all
  the time to fix little problems here and there and to support new
  hardware.

  Summary:

  Core:
   - Clk rate protection
   - Symbolic clk flags in debugfs output
   - Clk registration enabled clks while doing bookkeeping updates

  New Drivers:
   - Spreadtrum SC9860
   - HiSilicon hi3660 stub
   - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
   - Amlogic Meson-AXG
   - ASPEED BMC

  Removed Drivers:
   - TI OMAP 3xxx legacy clk (non-DT) support
   - asm*/clkdev.h got removed (not really a driver)

  Updates:
   - Renesas FDP1-0 module clock on R-Car M3-W
   - Renesas LVDS module clock on R-Car V3M
   - Misc fixes to pr_err() prints
   - Qualcomm MSM8916 audio fixes
   - Qualcomm IPQ8074 rounded out support for more peripherals
   - Qualcomm Alpha PLL variants
   - Divider code was using container_of() on bad pointers
   - Allwinner DE2 clks on H3
   - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
   - Mediatek clk driver compile test support
   - AT91 PMC clk suspend/resume restoration support
   - PLL issues fixed on si5351
   - Broadcom IProc PLL calculation updates
   - DVFS support for Armada mvebu CPU clks
   - Allwinner fixed post-divider support
   - TI clkctrl fixes and support for newer SoCs"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits)
  clk: aspeed: Handle inverse polarity of USB port 1 clock gate
  clk: aspeed: Fix return value check in aspeed_cc_init()
  clk: aspeed: Add reset controller
  clk: aspeed: Register gated clocks
  clk: aspeed: Add platform driver and register PLLs
  clk: aspeed: Register core clocks
  clk: Add clock driver for ASPEED BMC SoCs
  clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built
  clk: fix reentrancy of clk_enable() on UP systems
  clk: meson-axg: fix potential NULL dereference in axg_clkc_probe()
  clk: Simplify debugfs registration
  clk: Fix debugfs_create_*() usage
  clk: Show symbolic clock flags in debugfs
  clk: renesas: r8a7796: Add FDP clock
  clk: Move __clk_{get,put}() into private clk.h API
  clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks
  clk: Improve flags doc for of_clk_detect_critical()
  arch: Remove clkdev.h asm-generic from Kbuild
  clk: sunxi-ng: a83t: Add M divider to TCON1 clock
  clk: Prepare to remove asm-generic/clkdev.h
  ...
2018-02-01 16:56:07 -08:00
Stephen Boyd
c43a52cfd2 Merge branches 'clk-aspeed', 'clk-lock-UP', 'clk-mediatek' and 'clk-allwinner' into clk-next
* clk-aspeed:
  clk: aspeed: Handle inverse polarity of USB port 1 clock gate
  clk: aspeed: Fix return value check in aspeed_cc_init()
  clk: aspeed: Add reset controller
  clk: aspeed: Register gated clocks
  clk: aspeed: Add platform driver and register PLLs
  clk: aspeed: Register core clocks
  clk: Add clock driver for ASPEED BMC SoCs
  dt-bindings: clock: Add ASPEED constants

* clk-lock-UP:
  clk: fix reentrancy of clk_enable() on UP systems

* clk-mediatek:
  clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built
  clk: mediatek: Fix all warnings for missing struct clk_onecell_data
  clk: mediatek: fixup test-building of MediaTek clock drivers
  clk: mediatek: group drivers under indpendent menu

* clk-allwinner:
  clk: sunxi-ng: a83t: Add M divider to TCON1 clock
  clk: sunxi-ng: fix the A64/H5 clock description of DE2 CCU
  clk: sunxi-ng: add support for Allwinner H3 DE2 CCU
  dt-bindings: fix the binding of Allwinner DE2 CCU of A83T and H3
  clk: sunxi-ng: sun8i: a83t: Use sigma-delta modulation for audio PLL
  clk: sunxi-ng: sun8i: a83t: Add /2 fixed post divider to audio PLL
  clk: sunxi-ng: Support fixed post-dividers on NM style clocks
  clk: sunxi-ng: sun50i: a64: Add 2x fixed post-divider to MMC module clocks
  clk: sunxi-ng: Support fixed post-dividers on MP style clocks
  clk: sunxi: Use PTR_ERR_OR_ZERO()
2018-01-26 16:43:39 -08:00
Stephen Boyd
4d1d13a5ae Merge branches 'clk-remove-asm-clkdev', 'clk-debugfs-fixes', 'clk-renesas' and 'clk-meson' into clk-next
* clk-remove-asm-clkdev:
  clk: Move __clk_{get,put}() into private clk.h API
  clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks
  arch: Remove clkdev.h asm-generic from Kbuild
  clk: Prepare to remove asm-generic/clkdev.h
  blackfin: Use generic clkdev.h header

* clk-debugfs-fixes:
  clk: Simplify debugfs registration
  clk: Fix debugfs_create_*() usage
  clk: Show symbolic clock flags in debugfs
  clk: Improve flags doc for of_clk_detect_critical()

* clk-renesas:
  clk: renesas: r8a7796: Add FDP clock
  clk: renesas: cpg-mssr: Keep wakeup sources active during system suspend
  clk: renesas: mstp: Keep wakeup sources active during system suspend
  clk: renesas: r8a77970: Add LVDS clock

* clk-meson:
  clk: meson-axg: fix potential NULL dereference in axg_clkc_probe()
  clk: meson-axg: make local symbol axg_gp0_params_table static
  clk: meson-axg: fix return value check in axg_clkc_probe()
  clk: meson: mpll: use 64-bit maths in params_from_rate
  clk: meson-axg: add clock controller drivers
  clk: meson-axg: add clocks dt-bindings required header
  dt-bindings: clock: add compatible variant for the Meson-AXG
  clk: meson: make the spinlock naming more specific
  clk: meson: gxbb: remove IGNORE_UNUSED from mmc clocks
  clk: meson: gxbb: fix wrong clock for SARADC/SANA
2018-01-26 16:43:32 -08:00
Stephen Boyd
a2c09c12d4 Merge branches 'clk-at91', 'clk-imx7ulp', 'clk-axigen', 'clk-si5351' and 'clk-pxa' into clk-next
* clk-at91:
  clk: at91: pmc: Support backup for programmable clocks
  clk: at91: pmc: Save SCSR during suspend
  clk: at91: pmc: Wait for clocks when resuming

* clk-imx7ulp:
  clk: Don't touch hardware when reparenting during registration

* clk-axigen:
  clk: axi-clkgen: Round closest in round_rate() and recalc_rate()
  clk: axi-clkgen: Correctly handle nocount bit in recalc_rate()

* clk-si5351:
  clk: si5351: _si5351_clkout_reset_pll() can be static
  clk: si5351: Do not enable parent clocks on probe
  clk: si5351: Rename internal plls to avoid name collisions
  clk: si5351: Apply PLL soft reset before enabling the outputs
  clk: si5351: Add DT property to enable PLL reset
  clk: si5351: implement remove handler

* clk-pxa:
  clk: pxa: unbreak lookup of CLK_POUT
2018-01-26 16:41:52 -08:00
Stephen Boyd
74b48999b1 Merge branches 'clk-qcom-alpha-pll', 'clk-check-ops-ptr', 'clk-protect-rate' and 'clk-omap' into clk-next
* clk-qcom-alpha-pll:
  clk: qcom: add read-only alpha pll post divider operations
  clk: qcom: support for 2 bit PLL post divider
  clk: qcom: support Brammo type Alpha PLL
  clk: qcom: support Huayra type Alpha PLL
  clk: qcom: support for dynamic updating the PLL
  clk: qcom: support for alpha mode configuration
  clk: qcom: flag for 64 bit CONFIG_CTL
  clk: qcom: fix 16 bit alpha support calculation
  clk: qcom: support for alpha pll properties

* clk-check-ops-ptr:
  clk: check ops pointer on clock register

* clk-protect-rate:
  clk: fix set_rate_range when current rate is out of range
  clk: add clk_rate_exclusive api
  clk: cosmetic changes to clk_summary debugfs entry
  clk: add clock protection mechanism to clk core
  clk: use round rate to bail out early in set_rate
  clk: rework calls to round and determine rate callbacks
  clk: add clk_core_set_phase_nolock function
  clk: take the prepare lock out of clk_core_set_parent
  clk: fix incorrect usage of ENOSYS

* clk-omap:
  clk: ti: Drop legacy clk-3xxx-legacy code
2018-01-26 16:41:39 -08:00
David Lechner
a12aa8a68d clk: fix reentrancy of clk_enable() on UP systems
Reentrant calls to clk_enable() are not working on UP systems. This is
caused by the fact spin_trylock_irqsave() always returns true when
CONFIG_SMP=n (and CONFIG_DEBUG_SPINLOCK=n) which causes the reference
counting to not work correctly when clk_enable_lock() is called twice
before clk_enable_unlock() is called (this happens when clk_enable()
is called from within another clk_enable()).

This fixes the problem by skipping the call to spin_trylock_irqsave() on UP
systems and relying solely on reference counting. We also make sure to set
flags in this case so that we are not returning an uninitialized value.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-10 13:39:31 -08:00
Stephen Boyd
db3188fadf clk: Simplify debugfs registration
We don't need a goto here. Drop it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-10 13:13:23 -08:00
Geert Uytterhoeven
4c8326d5eb clk: Fix debugfs_create_*() usage
When exposing data access through debugfs, the correct
debugfs_create_*() functions must be used, matching the data
types.

Remove all casts from data pointers passed to debugfs_create_*()
functions, as such casts prevent the compiler from flagging bugs.

clk_core.rate and .accuracy are "unsigned long", hence casting
their addresses to "u32 *" exposed the wrong halves on big-endian
64-bit systems. Fix this by using debugfs_create_ulong() instead.

Octal permissions are preferred, as they are easier to read than
symbolic permissions. Hence replace "S_IRUGO" by "0444"
throughout.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[sboyd@codeaurora.org: Squash the octal change in too]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-10 13:13:23 -08:00
Geert Uytterhoeven
a6059ab981 clk: Show symbolic clock flags in debugfs
Currently the virtual "clk_flags" file in debugfs shows the numeric
value of the top-level framework flags for the specified clock.
Hence the user must manually interpret these values.

Moreover, on big-endian 64-bit systems, the wrong half of the value is
shown, due to the cast from "unsigned long *" to "u32 *".

Fix both issues by showing the symbolic flag names instead.
Any non-standard flags are shown as a hex number.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-10 13:13:22 -08:00
Geert Uytterhoeven
f7ae750367 clk: Improve flags doc for of_clk_detect_critical()
The "flags" parameter passed to of_clk_detect_critical() cannot be a
pointer to a real clk_core.flags field, as clk_core is private to the
clock framework internals.

Change the comment to refer to top-level framework flags instead.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-03 16:02:08 -08:00
Dong Aisheng
756efe1310 clk: use atomic runtime pm api in clk_core_is_enabled
Current clk_pm_runtime_put is using pm_runtime_put_sync which
is not safe to be called in clk_core_is_enabled as it should
be able to run in atomic context.

Thus use pm_runtime_put instead which is atomic safe.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 9a34b45397 ("clk: Add support for runtime PM")
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-12-26 17:34:03 -08:00
Stephen Boyd
f8f8f1d044 clk: Don't touch hardware when reparenting during registration
The orphan clocks reparent operation shouldn't touch the hardware
if clocks are enabled, otherwise it may get a chance to disable a
newly registered critical clock which triggers the warning below.

Assuming we have two clocks: A and B, B is the parent of A.
Clock A has flag: CLK_OPS_PARENT_ENABLE
Clock B has flag: CLK_IS_CRITICAL

Step 1:
Clock A is registered, then it becomes orphan.

Step 2:
Clock B is registered. Before clock B reach the critical clock enable
operation, orphan A will find the newly registered parent B and do
reparent operation, then parent B will be finally disabled in
__clk_set_parent_after() due to CLK_OPS_PARENT_ENABLE flag as there's
still no users of B which will then trigger the following warning.

WARNING: CPU: 0 PID: 0 at drivers/clk/clk.c:597 clk_core_disable+0xb4/0xe0
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00056-gdff1f66-dirty #1373
Hardware name: Generic DT based system
Backtrace:
[<c010c4bc>] (dump_backtrace) from [<c010c764>] (show_stack+0x18/0x1c)
 r6:600000d3 r5:00000000 r4:c0e26358 r3:00000000
[<c010c74c>] (show_stack) from [<c040599c>] (dump_stack+0xb4/0xe8)
[<c04058e8>] (dump_stack) from [<c0125c94>] (__warn+0xd8/0x104)
 r10:c0c21cd0 r9:c048aa78 r8:00000255 r7:00000009 r6:c0c1cd90 r5:00000000
 r4:00000000 r3:c0e01d34
[<c0125bbc>] (__warn) from [<c0125d74>] (warn_slowpath_null+0x28/0x30)
 r9:00000000 r8:ef00bf80 r7:c165ac4c r6:ef00bf80 r5:ef00bf80 r4:ef00bf80
[<c0125d4c>] (warn_slowpath_null) from [<c048aa78>] (clk_core_disable+0xb4/0xe0)
[<c048a9c4>] (clk_core_disable) from [<c048be88>] (clk_core_disable_lock+0x20/0x2c)
 r4:000000d3 r3:c0e0af00
[<c048be68>] (clk_core_disable_lock) from [<c048c224>] (clk_core_disable_unprepare+0x14/0x28)
 r5:00000000 r4:ef00bf80
[<c048c210>] (clk_core_disable_unprepare) from [<c048c270>] (__clk_set_parent_after+0x38/0x54)
 r4:ef00bd80 r3:000010a0
[<c048c238>] (__clk_set_parent_after) from [<c048daa8>] (clk_register+0x4d0/0x648)
 r6:ef00d500 r5:ef00bf80 r4:ef00bd80 r3:ef00bfd4
[<c048d5d8>] (clk_register) from [<c048dc30>] (clk_hw_register+0x10/0x1c)
 r9:00000000 r8:00000003 r7:00000000 r6:00000824 r5:00000001 r4:ef00d500
[<c048dc20>] (clk_hw_register) from [<c048e698>] (_register_divider+0xcc/0x120)
[<c048e5cc>] (_register_divider) from [<c048e730>] (clk_register_divider+0x44/0x54)
 r10:00000004 r9:00000003 r8:00000001 r7:00000000 r6:00000003 r5:00000001
 r4:f0810030
[<c048e6ec>] (clk_register_divider) from [<c0d3ff58>] (imx7ulp_clocks_init+0x558/0xe98)
 r7:c0e296f8 r6:c165c808 r5:00000000 r4:c165c808
[<c0d3fa00>] (imx7ulp_clocks_init) from [<c0d24db0>] (of_clk_init+0x118/0x1e0)
 r10:00000001 r9:c0e01f68 r8:00000000 r7:c0e01f60 r6:ef7f8974 r5:ef0035c0
 r4:00000006
[<c0d24c98>] (of_clk_init) from [<c0d04a50>] (time_init+0x2c/0x38)
 r10:efffed40 r9:c0d61a48 r8:c0e78000 r7:c0e07900 r6:ffffffff r5:c0e78000
 r4:00000000
[<c0d04a24>] (time_init) from [<c0d00b8c>] (start_kernel+0x218/0x394)
[<c0d00974>] (start_kernel) from [<6000807c>] (0x6000807c)
 r10:00000000 r9:410fc075 r8:6000406a r7:c0e0c930 r6:c0d61a44 r5:c0e07918
 r4:c0e78294

We know that the clk isn't enabled with any sort of prepare_count
here so we don't need to enable anything to prevent a race. And
we're holding the prepare mutex so set_rate/set_parent can't race
here either. Based on an earlier patch by Dong Aisheng.

Fixes: fc8726a2c0 ("clk: core: support clocks which requires parents enable (part 2)")
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Reported-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-12-21 17:57:27 -08:00
Jerome Brunet
6562fbcf3a clk: fix set_rate_range when current rate is out of range
Calling clk_core_set_rate() with core->req_rate is basically a no-op
because of the early bail-out mechanism.

This may leave the clock in inconsistent state if the rate is out the
requested range. Calling clk_core_set_rate() with the closest rate
limit could solve the problem but:
- The underlying determine_rate() callback needs to account for this
  corner case (rounding within the range, if possible)
- if only round_rate() is available, we rely on luck unfortunately.

Fixes: 1c8e600440 ("clk: Add rate constraints to clocks")
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-11-jbrunet@baylibre.com
2017-12-19 16:35:35 -08:00
Jerome Brunet
55e9b8b7b8 clk: add clk_rate_exclusive api
Using clock rate protection, we can now provide a way for clock consumer
to claim exclusive control over the rate of a producer

So far, rate change operations have been a "last write wins" affair. This
changes allows drivers to explicitly protect against this behavior, if
required.

Of course, if exclusivity over a producer is claimed more than once, the
rate is effectively locked as exclusivity cannot be preempted

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-10-jbrunet@baylibre.com
2017-12-19 16:35:34 -08:00
Jerome Brunet
c5ce26edb4 clk: cosmetic changes to clk_summary debugfs entry
clk_summary debugfs entry was already well over the traditional 80
characters per line limit but it grew even larger with the addition of
clock protection.

   clock                         enable_cnt  prepare_cnt  protect_cnt        rate   accuracy   phase
----------------------------------------------------------------------------------------------------
 wifi32k                                  1            1            0       32768          0 0
 vcpu                                     0            0            0  2016000000          0 0
 xtal                                     5            5            0    24000000          0 0

This patch reduce the width a bit:
                                 enable  prepare  protect
   clock                          count    count    count        rate   accuracy   phase
----------------------------------------------------------------------------------------
 wifi32k                              1        1        0       32768          0 0
 vcpu                                 0        0        0  2016000000          0 0
 xtal                                 5        5        0    24000000          0 0

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-8-jbrunet@baylibre.com
2017-12-19 16:17:52 -08:00
Jerome Brunet
e55a839a7a clk: add clock protection mechanism to clk core
The patch adds clk_core_protect and clk_core_unprotect to the internal
CCF API. These functions allow to set a new constraint along the clock
tree to prevent any change, even indirect, which may result in rate
change or glitch.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-7-jbrunet@baylibre.com
2017-12-19 16:17:49 -08:00
Jerome Brunet
ca5e089a32 clk: use round rate to bail out early in set_rate
The current implementation of clk_core_set_rate_nolock() bails out early
if the requested rate is exactly the same as the one set. It should bail
out if the request would not result in a rate a change. This is important
when the rate is not exactly what is requested, which is fairly common
with PLLs.

Ex: provider able to give any rate with steps of 100Hz
 - 1st consumer request 48000Hz and gets it.
 - 2nd consumer request 48010Hz as well. If we were to perform the usual
   mechanism, we would get 48000Hz as well. The clock would not change so
   there is no point performing any checks to make sure the clock can
   change, we know it won't.

This is important to prepare the addition of the clock protection
mechanism

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-6-jbrunet@baylibre.com
2017-12-19 16:17:46 -08:00
Jerome Brunet
0f6cc2b8e9 clk: rework calls to round and determine rate callbacks
Rework the way the callbacks round_rate() and determine_rate() are called.
The goal is to do this at a single point and make it easier to add
conditions before calling them.

Because of this factorization, rate returned by determine_rate() is also
checked against the min and max rate values

This rework is done to ease the integration of "protected" clock
functionality.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-5-jbrunet@baylibre.com
2017-12-19 16:17:43 -08:00
Jerome Brunet
9e4d04adeb clk: add clk_core_set_phase_nolock function
Create a core function for set_phase, as it is done for set_rate and
set_parent.

This rework is done to ease the integration of "protected" clock
functionality.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-4-jbrunet@baylibre.com
2017-12-19 16:17:40 -08:00
Jerome Brunet
91baa9ffe6 clk: take the prepare lock out of clk_core_set_parent
Rework set_parent core function so it can be called when the prepare lock
is already held by the caller.

This rework is done to ease the integration of the "protected" clock
functionality.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-3-jbrunet@baylibre.com
2017-12-19 16:17:37 -08:00
Jerome Brunet
56e7ceddbe clk: fix incorrect usage of ENOSYS
ENOSYS is special and should only be used for incorrect syscall number.
It does not seem to be the case here.

Reported by checkpatch.pl while working on clock protection.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-2-jbrunet@baylibre.com
2017-12-19 16:17:33 -08:00
Jerome Brunet
29fd2a34ef clk: check ops pointer on clock register
Nothing really prevents a provider from (trying to) register a clock
without providing the clock ops structure.

We do check the individual fields before using them, but not the
structure pointer itself. This may have the usual nasty consequences when
the pointer is dereferenced, most likely when checking one the field
during the initialization.

This is fixed by returning an error on clock register if the ops pointer
is NULL.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171219083329.24746-1-jbrunet@baylibre.com
2017-12-19 11:44:21 -08:00
Marek Szyprowski
588fb54b0c clk: Manage proper runtime PM state in clk_change_rate()
clk_change_rate() propagates rate change down to all its children. Such
operation requires managing proper runtime PM state of each child, what
was missing. Add needed calls to clk_pm_runtime*() to ensure that
set_rate() clock callback is called on runtime active clock.

This fixes following issue found on Exynos5433 TM2 board with devfreq
enabled:

Synchronous External Abort: synchronous external abort (0x96000210) at 0xffffff80093f5600
Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5 Comm: kworker/u16:0 Not tainted 4.15.0-rc1-next-20171129+ #4
Hardware name: Samsung TM2 board (DT)
Workqueue: devfreq_wq devfreq_monitor
task: ffffffc0ca96b600 task.stack: ffffff80093a8000
pstate: a0000085 (NzCv daIf -PAN -UAO)
pc : clk_divider_set_rate+0x54/0x118
lr : clk_divider_set_rate+0x44/0x118
...
Process kworker/u16:0 (pid: 5, stack limit = 0xffffff80093a8000)
Call trace:
 clk_divider_set_rate+0x54/0x118
 clk_change_rate+0xfc/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_core_set_rate_nolock+0x138/0x148
 clk_set_rate+0x28/0x50
 exynos_bus_passive_target+0x6c/0x11c
 update_devfreq_passive+0x58/0xb4
 devfreq_passive_notifier_call+0x50/0x5c
 notifier_call_chain+0x4c/0x88
 __srcu_notifier_call_chain+0x54/0x80
 srcu_notifier_call_chain+0x14/0x1c
 update_devfreq+0x100/0x1b4
 devfreq_monitor+0x2c/0x88
 process_one_work+0x148/0x3d8
 worker_thread+0x13c/0x3f8
 kthread+0x100/0x12c
 ret_from_fork+0x10/0x18

Reported-by: Chanwoo Choi <cw00.choi@samsung.com>
Fixes: 9a34b45397 ("clk: Add support for runtime PM")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-12-05 15:20:03 -08:00
Stephen Boyd
2dd850ef6e Merge branch 'clk-devm-provider' into clk-next
* clk-devm-provider:
  clk: qcom: common: Migrate to devm_* APIs for resets and clk providers
  clk: Add devm_of_clk_add_hw_provider()/del_provider() APIs
2017-11-14 10:07:39 -08:00
Stephen Boyd
aa795c41d9 clk: Add devm_of_clk_add_hw_provider()/del_provider() APIs
Sometimes we only have one of_clk_del_provider() call in driver
error and remove paths, because we're missing a
devm_of_clk_add_hw_provider() API. Introduce the API so we can
convert drivers to use this and potentially reduce the amount of
code needed to remove providers in drivers.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-11-01 23:37:19 -07:00
Stephen Boyd
e7cc33358a Merge branch 'clk-pm-runtime' into clk-next
* clk-pm-runtime:
  clk: samsung: exynos-audss: Add support for runtime PM
  clk: samsung: exynos-audss: Use local variable for controller's device
  clk: samsung: exynos5433: Add support for runtime PM
  clk: samsung: Add support for runtime PM
  clk: Add support for runtime PM
2017-09-29 16:07:28 -07:00
Marek Szyprowski
9a34b45397 clk: Add support for runtime PM
Registers for some clocks might be located in the SOC area, which are under the
power domain. To enable access to those registers respective domain has to be
turned on. Additionally, registers for such clocks will usually loose its
contents when power domain is turned off, so additional saving and restoring of
them might be needed in the clock controller driver.

This patch adds basic infrastructure in the clocks core to allow implementing
driver for such clocks under power domains. Clock provider can supply a
struct device pointer, which is the used by clock core for tracking and managing
clock's controller runtime pm state. Each clk_prepare() operation
will first call pm_runtime_get_sync() on the supplied device, while
clk_unprepare() will do pm_runtime_put_sync() at the end.

Additional calls to pm_runtime_get/put functions are required to ensure that any
register access (like calculating/changing clock rates and unpreparing/disabling
unused clocks on boot) will be done with clock controller in runtime resumend
state.

When one wants to register clock controller, which make use of this feature, he
has to:
1. Provide a struct device to the core when registering the provider.
2. Ensure to enable runtime PM for that device before registering clocks.
3. Make sure that the runtime PM status of the controller device reflects
   the HW state.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1503302703-13801-2-git-send-email-m.szyprowski@samsung.com
2017-09-07 15:25:13 -07:00
Rob Herring
1667393126 clk: Convert to using %pOF instead of full_name
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: James Liao <jamesjj.liao@mediatek.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-07-21 15:49:54 -07:00
Markus Elfring
1808a32019 clk: Improve a size determination in two functions
Replace the specification of two data structures by pointer dereferences
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-04-21 19:47:02 -07:00
Markus Elfring
4d32758671 clk: Replace four seq_printf() calls by seq_putc()
Four single characters should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-04-21 19:45:24 -07:00
Peter De Schrijver
17c34c5667 clk: aggregate return codes of notify chains
In case there are multiple notify chains for the same clocks (because they
were registered by different users), we need to propagate potential failure
of any single one of them to the caller. Otherwise we eg risk violating the
V/f curve when a notifier is used for DVFS.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2017-04-12 18:51:41 +02:00
Peter De Schrijver
92031575c3 clk: add clk_possible_parents debugfs file
For validation purposes, it's often useful to be able to retrieve the list
of possible parents in userspace. Add a debugfs file for every clock which
has more than 1 possible parent.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
[sboyd@codeaurora.org: Remove useless cast from void and extra
newline]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2017-04-12 18:51:38 +02:00
Leonard Crestez
253160a8ad clk: core: Copy connection id
Some drivers use sprintf to build clk connection id names but the clk
core will save those strings and occasionally print them back. Duplicate
the con_id strings instead of fixing all the users.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-03-07 05:19:20 -08:00
Jean-Francois Moine
3174b0c9a6 clk: core: Force setting the phase delay when no change
This patch reverts commit 023bd7166b ("clk: skip unnecessary
set_phase if nothing to do"), fixing two problems:

* in some SoCs, the hardware phase delay depends on the rate ratio of
  the clock and its parent. So, changing this ratio may imply to set
  new hardware values, even if the logical delay is the same.

* when the delay was the same as previously, an error was returned.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Fixes: 023bd7166b ("clk: skip unnecessary set_phase if nothing to do")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-30 14:52:26 -07:00
Stephen Boyd
74002fcde0 clk: Simplify __of_clk_get_hw_from_provider()
__of_clk_get_hw_from_provider() is confusing because it will
return EPROBE_DEFER if there isn't a ->get() or ->get_hw()
function pointer in a provider. That's just a bug though, and we
used to NULL pointer exception when ->get() was missing anyway,
so let's make this more obvious that they're not optional. The
assumption is that most providers will implement ->get_hw() so we
only fallback to the ->get() function if necessary. This
clarifies the intent and removes any possibility of probe defer
happening if clk providers are buggy.

Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-26 12:28:27 -07:00
Stephen Boyd
f155d15b64 clk: Return errors from clk providers in __of_clk_get_from_provider()
Before commit 0861e5b8cf (clk: Add clk_hw OF clk providers,
2016-02-05) __of_clk_get_from_provider() would return an error
pointer of the provider's choosing if there was a provider
registered and EPROBE_DEFER otherwise. After that commit, it
would return EPROBE_DEFER regardless of whether or not the
provider returned an error. This is odd and can lead to behavior
where clk consumers keep probe deferring when they should be
seeing some other error.

Let's restore the previous behavior where we only return
EPROBE_DEFER when there isn't a provider in our of_clk_providers
list. Otherwise, return the error from the last provider we find
that matches the node.

Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Fixes: 0861e5b8cf ("clk: Add clk_hw OF clk providers")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-15 14:32:23 -07:00
Masahiro Yamada
8a23133c7a clk: use ERR_CAST() for __clk_create_clk()
This code is clear enough, but the intention will be even clearer
with this.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-12 18:17:04 -07:00
Ricardo Ribalda Delgado
989eafd0b6 clk: core: Avoid double initialization of clocks
Some clock providers can be initialized via of_clk_init() and also via
platform device probe.

Avoid double initialization of them by setting the OF_POPULATED flag.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-12 18:01:58 -07:00
Michael Turquette
904e6ead02 clk: migrate ref counts when orphans are reunited
It's always nice to see families reunited, and this is equally true when
talking about parent clocks and their children. However, if the orphan
clk had a positive prepare_count or enable_count, then we would not
migrate those counts up the parent chain correctly.

This has manifested with the recent critical clocks feature, which often
enables clocks very early, before their parents have been registered.

Fixed by replacing the call to clk_core_reparent with calls to
__clk_set_parent_{before,after}.

Cc: James Liao <jamesjj.liao@mediatek.com>
Cc: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
[sboyd@codeaurora.org: Recalc accuracies and rates too]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-11 18:06:50 -07:00
Dong Aisheng
fc8726a2c0 clk: core: support clocks which requires parents enable (part 2)
On Freescale i.MX7D platform, all clocks operations, including
enable/disable, rate change and re-parent, requires its parent clock on.
Current clock core can not support it well.
This patch adding flag CLK_OPS_PARENT_ENABLE to handle this special case in
clock core that enable its parent clock firstly for each operation and
disable it later after operation complete.

The patch part 2 fixes set clock rate and set parent while its parent
is off. The most special case is for set_parent() operation which requires
all parents including both old and new one to be enabled at the same time
during the operation.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
[sboyd@codeaurora.org: Move set_rate tracepoint after prepare_enable]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-07-01 17:42:56 -07:00
Dong Aisheng
a4b3518d14 clk: core: support clocks which requires parents enable (part 1)
On Freescale i.MX7D platform, all clocks operations, including
enable/disable, rate change and re-parent, requires its parent
clock enable. Current clock core can not support it well.
This patch introduce a new flag CLK_OPS_PARENT_ENABLE to handle this
special case in clock core that enable its parent clock firstly for
each operation and disable it later after operation complete.

The patch part 1 fixes the possible disabling clocks while its parent
is off during kernel booting phase in clk_disable_unused_subtree().

Before the completion of kernel booting, clock tree is still not built
completely, there may be a case that the child clock is on but its
parent is off which could be caused by either HW initial reset state
or bootloader initialization.

Taking bootloader as an example, we may enable all clocks in HW by default.
And during kernel booting time, the parent clock could be disabled in its
driver probe due to calling clk_prepare_enable and clk_disable_unprepare.
Because it's child clock is only enabled in HW while its SW usecount
in clock tree is still 0, so clk_disable of parent clock will gate
the parent clock in both HW and SW usecount ultimately. Then there will
be a child clock is still on in HW but its parent is already off.

Later in clk_disable_unused(), this clock disable accessing while its
parent off will cause system hang due to the limitation of HW which
must require its parent on.

This patch simply enables the parent clock first before disabling
if flag CLK_OPS_PARENT_ENABLE is set in clk_disable_unused_subtree().
This is a simple solution and only affects booting time.

After kernel booting up the clock tree is already created, there will
be no case that child is off but its parent is off.
So no need do this checking for normal clk_disable() later.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-07-01 17:40:23 -07:00
Dong Aisheng
7ec986efed clk: move clk_disable_unused after clk_core_disable_unprepare function
No function level change, just moving code place.
clk_disable_unused function will need to call clk_core_prepare_enable/
clk_core_disable_unprepare when adding CLK_OPS_PARENT_ENABLE features.
So move it after clk_core_disable_unprepare to avoid adding forward
declared functions later.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-07-01 17:40:20 -07:00
Dong Aisheng
a6adc30ba7 clk: introduce clk_core_enable_lock and clk_core_disable_lock functions
This can be useful when clock core wants to enable/disable clocks.
Then we don't have to convert the struct clk_core to struct clk to call
clk_enable/clk_disable which is a bit un-align with exist using.

And after introduce clk_core_{enable|disable}_lock, we can refine
clk_enable and clk_disable a bit.

As well as clk_core_{enable|disable}_lock, we also added
clk_core_{prepare|unprepare}_lock and clk_core_prepare_enable/
clk_core_unprepare_disable for clock core to easily use.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-07-01 17:40:18 -07:00
Peng Fan
2d5b520cfe clk: correct comments for __clk_determine_rate
Correct comments for __clk_determine_rate.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-06-20 17:59:23 -07:00
Lee Jones
06b37e4a6e clk: Remove unused variable
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-06-20 17:46:30 -07:00
Michael Turquette
071a0cb66c Merge commit 'f17a0dd1c2e0' into clk-next 2016-06-16 22:07:08 -07:00
Paul E. McKenney
f17a0dd1c2 clk: Use _rcuidle suffix to allow clk_core_enable() to used from idle
This commit fixes the RCU use-from-idle bug corresponding the following
splat:

> [ INFO: suspicious RCU usage. ]
> 4.6.0-rc5-next-20160426+ #1127 Not tainted
> -------------------------------
> include/trace/events/clk.h:45 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
>
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 1, debug_locks = 0
> RCU used illegally from extended quiescent state!
> 2 locks held by swapper/0/0:
>  #0:  (&oh->hwmod_key#30){......}, at: [<c0121afc>] omap_hwmod_enable+0x18/0x44
>  #1:  (enable_lock){......}, at: [<c0630684>] clk_enable_lock+0x18/0x124
>
> stack backtrace:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1127
> Hardware name: Generic OMAP36xx (Flattened Device Tree)
> [<c0110290>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
> [<c010c3a8>] (show_stack) from [<c047fd68>] (dump_stack+0xb0/0xe4)
> [<c047fd68>] (dump_stack) from [<c06315c0>] (clk_core_enable+0x1e0/0x36c)
> [<c06315c0>] (clk_core_enable) from [<c0632298>] (clk_enable+0x1c/0x38)
> [<c0632298>] (clk_enable) from [<c01204e0>] (_enable_clocks+0x18/0x7c)
> [<c01204e0>] (_enable_clocks) from [<c012137c>] (_enable+0x114/0x2ec)
> [<c012137c>] (_enable) from [<c0121b08>] (omap_hwmod_enable+0x24/0x44)
> [<c0121b08>] (omap_hwmod_enable) from [<c0122ad0>] (omap_device_enable+0x3c/0x90)
> [<c0122ad0>] (omap_device_enable) from [<c0122b34>] (_od_runtime_resume+0x10/0x38)
> [<c0122b34>] (_od_runtime_resume) from [<c052cc00>] (__rpm_callback+0x2c/0x60)
> [<c052cc00>] (__rpm_callback) from [<c052cc54>] (rpm_callback+0x20/0x80)
> [<c052cc54>] (rpm_callback) from [<c052df7c>] (rpm_resume+0x3d0/0x6f0)
> [<c052df7c>] (rpm_resume) from [<c052e2e8>] (__pm_runtime_resume+0x4c/0x64)
> [<c052e2e8>] (__pm_runtime_resume) from [<c04bf2c4>] (omap2_gpio_resume_after_idle+0x54/0x68)
> [<c04bf2c4>] (omap2_gpio_resume_after_idle) from [<c01269dc>] (omap3_enter_idle_bm+0xfc/0x1ec)
> [<c01269dc>] (omap3_enter_idle_bm) from [<c0601888>] (cpuidle_enter_state+0x80/0x3d4)
> [<c0601888>] (cpuidle_enter_state) from [<c0183b08>] (cpu_startup_entry+0x198/0x3a0)
> [<c0183b08>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
> [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: <linux-omap@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <linux-clk@vger.kernel.org>
2016-06-15 13:45:22 -07:00
Paul E. McKenney
2f87a6ea1b clk: Add _rcuidle tracepoints to allow clk_core_disable() use from idle
This commit adds an _rcuidle suffix to a pair of trace events to
prevent the following splat:

> ===============================
> [ INFO: suspicious RCU usage. ]
> 4.6.0-rc5-next-20160426+ #1114 Not tainted
> -------------------------------
> include/trace/events/clk.h:59 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
>
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 1, debug_locks = 0
> RCU used illegally from extended quiescent state!
> 2 locks held by swapper/0/0:
>  #0:  (&oh->hwmod_key#30){......}, at: [<c0121b40>] omap_hwmod_idle+0x18/0x44
>  #1:  (enable_lock){......}, at: [<c0630998>] clk_enable_lock+0x18/0x124
>
> stack backtrace:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1114
> Hardware name: Generic OMAP36xx (Flattened Device Tree)
> [<c0110290>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
> [<c010c3a8>] (show_stack) from [<c047fd68>] (dump_stack+0xb0/0xe4)
> [<c047fd68>] (dump_stack) from [<c0631618>] (clk_core_disable+0x17c/0x348)
> [<c0631618>] (clk_core_disable) from [<c0632774>] (clk_disable+0x24/0x30)
> [<c0632774>] (clk_disable) from [<c0120590>] (_disable_clocks+0x18/0x7c)
> [<c0120590>] (_disable_clocks) from [<c0121680>] (_idle+0x12c/0x230)
> [<c0121680>] (_idle) from [<c0121b4c>] (omap_hwmod_idle+0x24/0x44)
> [<c0121b4c>] (omap_hwmod_idle) from [<c0122c24>] (omap_device_idle+0x3c/0x90)
> [<c0122c24>] (omap_device_idle) from [<c052cc00>] (__rpm_callback+0x2c/0x60)
> [<c052cc00>] (__rpm_callback) from [<c052cc54>] (rpm_callback+0x20/0x80)
> [<c052cc54>] (rpm_callback) from [<c052d150>] (rpm_suspend+0x100/0x768)
> [<c052d150>] (rpm_suspend) from [<c052ec58>] (__pm_runtime_suspend+0x64/0x84)
> [<c052ec58>] (__pm_runtime_suspend) from [<c04bf25c>] (omap2_gpio_prepare_for_idle+0x5c/0x70)
> [<c04bf25c>] (omap2_gpio_prepare_for_idle) from [<c0125568>] (omap_sram_idle+0x140/0x244)
> [<c0125568>] (omap_sram_idle) from [<c01269dc>] (omap3_enter_idle_bm+0xfc/0x1ec)
> [<c01269dc>] (omap3_enter_idle_bm) from [<c0601bdc>] (cpuidle_enter_state+0x80/0x3d4)
> [<c0601bdc>] (cpuidle_enter_state) from [<c0183b08>] (cpu_startup_entry+0x198/0x3a0)
> [<c0183b08>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
> [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: <linux-omap@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <linux-clk@vger.kernel.org>
2016-06-15 13:45:18 -07:00
Maxime Ripard
ef56b79b66 clk: fix critical clock locking
The critical clock handling in __clk_core_init isn't taking the enable lock
before calling clk_core_enable, which in turns triggers the warning in the
lockdep_assert_held call in that function when lockep is enabled.

Add the calls to clk_enable_lock/unlock to make sure it doesn't happen.

Fixes: 32b9b10961 ("clk: Allow clocks to be marked as CRITICAL")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-05-19 14:09:30 -07:00
Masahiro Yamada
c47265ad64 clk: fix comment of devm_clk_hw_register()
Unlike devm_clk_register(), devm_clk_hw_register() returns integer.
So, the statement "Clocks returned from this function ..." sounds
odd.  Adjust the comment for this new API.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-05-02 17:52:03 -07:00
Stephen Boyd
58657d189a Merge branch 'clk-hw-register' (early part) into clk-next
* 'clk-hw-register' (early part):
  clk: fixed-rate: Add hw based registration APIs
  clk: gpio: Add hw based registration APIs
  clk: composite: Add hw based registration APIs
  clk: fractional-divider: Add hw based registration APIs
  clk: fixed-factor: Add hw based registration APIs
  clk: mux: Add hw based registration APIs
  clk: gate: Add hw based registration APIs
  clk: divider: Add hw based registration APIs
  clkdev: Add clk_hw based registration APIs
  clk: Add clk_hw OF clk providers
  clk: Add {devm_}clk_hw_{register,unregister}() APIs
  clkdev: Remove clk_register_clkdevs()
2016-04-21 14:47:18 -07:00
Stephen Boyd
0861e5b8cf clk: Add clk_hw OF clk providers
Now that we have a clk registration API that doesn't return
struct clks, we need to have some way to hand out struct clks via
the clk_get() APIs that doesn't involve associating struct clk
pointers with an OF node. Currently we ask the OF provider to
give us a struct clk pointer for some clkspec, turn that struct
clk into a struct clk_hw and then allocate a new struct clk to
return to the caller.

Let's add a clk_hw based OF provider hook that returns a struct
clk_hw directly, so that we skip the intermediate step of
converting from struct clk to struct clk_hw. Eventually when
we've converted all OF clk providers to struct clk_hw based APIs
we can remove the struct clk based ones.

It should also be noted that we change the onecell provider to
have a flex array instead of a pointer for the array of clk_hw
pointers. This allows providers to allocate one structure of the
correct length in one step instead of two.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-19 16:52:22 -07:00
Stephen Boyd
4143804c4f clk: Add {devm_}clk_hw_{register,unregister}() APIs
We've largely split the clk consumer and provider APIs along
struct clk and struct clk_hw, but clk_register() still returns a
struct clk pointer for each struct clk_hw that's registered.
Eventually we'd like to only allocate struct clks when there's a
user, because struct clk is per-user now, so clk_register() needs
to change.

Let's add new APIs to register struct clk_hws, but this time
we'll hide the struct clk from the caller by returning an int
error code. Also add an unregistration API that takes the clk_hw
structure that was passed to the registration API. This way
provider drivers never have to deal with a struct clk pointer
unless they're using the clk consumer APIs.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-19 16:51:58 -07:00
Lee Jones
d56f8994b6 clk: Provide OF helper to mark clocks as CRITICAL
This call matches clocks which have been marked as critical in DT
and sets the appropriate flag.  These flags can then be used to
mark the clock core flags appropriately prior to registration.

Legacy bindings requiring this feature must add the clock-critical
property to their binding descriptions, as it is not a part of
common-clock binding.

Cc: devicetree@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1455225554-13267-4-git-send-email-mturquette@baylibre.com
2016-04-09 11:58:11 -07:00
Lee Jones
2e20fbf592 clk: WARN_ON about to disable a critical clock
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1455225554-13267-3-git-send-email-mturquette@baylibre.com
2016-04-09 11:58:10 -07:00
Lee Jones
32b9b10961 clk: Allow clocks to be marked as CRITICAL
Critical clocks are those which must not be gated, else undefined
or catastrophic failure would occur.  Here we have chosen to
ensure the prepare/enable counts are correctly incremented, so as
not to confuse users with enabled clocks with no visible users.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1455225554-13267-2-git-send-email-mturquette@baylibre.com
2016-04-09 11:58:10 -07:00
Stephen Boyd
929e7f3bc7 clk: Make of_clk_get_parent_count() return unsigned ints
Russell King recently pointed out a bug in the clk-gpio code
where it fails to register the clk if of_clk_get_parent_count()
returns an error because the "clocks" property isn't present in
the DT node. If we're trying to count parents from DT we'd like
to know the count, not if there is a "clocks" property or not.
Furthermore, some drivers are assigning the return value to their
clk_init_data::num_parents member which is unsigned, leading to
potentially large numbers of parents when the property isn't
present.

Let's change the API to return an unsigned int instead of an int.
All the callers just want to know the count anyway, and this
avoids the bug that was in the clk-gpio driver.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-26 16:01:32 -08:00
Geert Uytterhoeven
3e5dd6f6e6 clk: Ignore disabled DT clock providers
of_clk_init() uses for_each_matching_node_and_match() to find clock
providers, which returns all matching device nodes, whether they are
enabled or not. Hence clock providers that are disabled explicitly in DT
using e.g.

	"status = "disabled";

are still activated.

Add a check to ignore device nodes that are not enabled, like
of_irq_init() does.

Reported-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-26 09:39:38 -08:00
Shawn Lin
023bd7166b clk: skip unnecessary set_phase if nothing to do
Let's compare the degrees from clk_set_rate with
clk->core->phase. If the requested degrees is already
there, skip the following steps.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[sboyd@codeaurora.org: s/drgrees/degrees/ in commit text]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-25 18:10:51 -08:00
Stephen Boyd
706d5c73e3 clk: Update some outdated comments
__clk_init() was renamed to __clk_core_init() but these comments
weren't updated.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-22 15:43:41 -08:00
Stephen Boyd
fa459711a0 Revert "clk: avoid circular clock topology"
This reverts commit 858d588156.

Joachim reports that this commit breaks lpc18xx boot. This is
because the hardware has circular clk topology where PLLs can
feed into dividers and the same dividers can feed into the PLLs.
The hardware is designed this way so that you can choose to put
the divider before the PLL or after the PLL depending on what you
configure to be the parent of the divider and what you configure
to be the parent of the PLL.

So let's drop this patch for now because we have hardware that
actually has loops. A future patch could check for circular
parents when we change parents and fail the switch, but that's
probably best left to some debugging Kconfig option so that we
don't suffer the sanity checking cost all the time.

Reported-by: Joachim Eastwood <manabian@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-22 15:01:39 -08:00
Andrew F. Davis
fb4dd22203 clk: Make of_clk_get_from_provider() available to modules
Export symbol of_clk_get_from_provider so it can be used in
loadable kernel modules

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2016-02-17 16:50:13 -08:00
Masahiro Yamada
2430a94d1e clk: fix __clk_init_parent() for single parent clocks
Before commit b3d192d5121f ("clk: simplify __clk_init_parent()"),
__clk_init_parent() called .get_parent() only for multi-parent
clocks.  That commit changed the behavior to call .get_parent()
if available even for single-parent clocks and root clocks.

It turned out a problem because there are some single-parent clocks
that implement .get_parent() callback and return non-zero index.
The SOCFPGA clock is the case; the commit broke the SOCFPGA boards.

To keep the original behavior, invoke .get_parent() only when
num_parents is greater than 1.

Fixes: b3d192d5121f ("clk: simplify __clk_init_parent()")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-09 10:18:48 -08:00
Stephen Boyd
47b0eeb3dc clk: Deprecate CLK_IS_ROOT
We don't use CLK_IS_ROOT but in a few places in the common clk
framework core. Let's replace those checks with a check for the
number of parents a clk has instead of the flag, freeing up one
flag for something else. We don't remove the flag yet so that
things keep building, but we'll remove it once all drivers have
removed their flag usage.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-06 23:38:26 -08:00
Insu Yun
4106a3d9eb clk: unlock for handling unregistered clock
If clock is already unregistered, it returns with holding lock.
It needs to be unlocked.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
[sboyd@codeaurora.org: Use goto instead]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:54:07 -08:00
Masahiro Yamada
e8f0e68ec0 clk: slightly optimize clk_core_set_parent()
If clk_fetch_parent_index() fails, p_rate is unused.  Move the
assignment after the error checking.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:17 -08:00
Masahiro Yamada
470b5e2f97 clk: simplify clk_fetch_parent_index() function
The clk_core_get_parent_by_index can be used as a helper function
to simplify the implementation of clk_fetch_parent_index().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:16 -08:00
Masahiro Yamada
508f884a66 clk: make sure parent is not NULL in clk_fetch_parent_index()
If parent is given with NULL, clk_fetch_parent_index() could return
a positive index value.

Currently, parent is checked by the callers of this function, but
it would be safer to do it in this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:15 -08:00
Masahiro Yamada
0e8f6e499e clk: walk the orphan clock list more simply
This loop can be much simpler. If a new parent is available for
orphan clocks, __clk_init_parent(orphan) can detect it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:14 -08:00
Masahiro Yamada
858d588156 clk: avoid circular clock topology
Currently, clk_register() never checks a circular parent looping,
but clock providers could register such an insane clock topology.
For example, "clk_a" could have "clk_b" as a parent, and vice versa.
In this case, clk_core_reparent() creates a circular parent list
and __clk_recalc_accuracies() calls itself recursively forever.

The core infrastructure should be kind enough to bail out, showing
an appropriate error message in such a case.  This helps to easily
find a bug in clock providers.  (uh, I made such a silly mistake
when I was implementing my clock providers first.  I was upset
because the kernel did not respond, without any error message.)

This commit adds a new helper function, __clk_is_ancestor().  It
returns true if the second argument is a possible ancestor of the
first one.  If a clock core is a possible ancestor of itself, it
would make a loop when it were registered.  That should be detected
as an error.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:13 -08:00
Masahiro Yamada
5146e0b059 clk: simplify __clk_init_parent()
The translation from the index into clk_core is done by
clk_core_get_parent_by_index().  The if-block for num_parents == 1
case is duplicating the code in the clk_core_get_parent_by_index().

Drop the "if (num_parents == 1)" from the special case.  Instead,
set the index to zero if .get_parent() is missing.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:10 -08:00
Masahiro Yamada
3c8e77dd20 clk: move checking .get_parent to __clk_core_init()
The .get_parent is mandatory for multi-parent clocks.  Move the check
to __clk_core_init(), like other callback checkings.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
[sboyd@codeaurora.org: Squashed in error path handling, fix typos
in commit message]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:52:06 -08:00
Masahiro Yamada
c44fccb5f7 clk: replace pr_warn() with pr_err() for fatal cases
These three cases let clk_register() fail.  They should be considered
as error messages.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:59 -08:00
Masahiro Yamada
3c436bf95a clk: drop the initial core->parents look-ups from __clk_core_init()
The core->parents is a cache to save expensive clock parent look-ups.
It will be filled as needed later.  We do not have to do it here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:54 -08:00
Masahiro Yamada
88cfbef2ac clk: simplify clk_core_get_parent_by_index()
Drop the "if (!core->parents)" case and refactor the function a bit
because core->parents is always allocated.  (Strictly speaking, it is
ZERO_SIZE_PTR if core->num_parents == 0, but such a case is omitted
by the if-conditional above.)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:50 -08:00
Masahiro Yamada
176d11690b clk: move core->parents allocation to clk_register()
Currently, __clk_core_init() allows failure of the kcalloc() for the
core->parents.  So, clk_fetch_parent_index() and __clk_init_parent()
also try to allocate core->parents in case it has not been allocated
yet.  Scattering memory allocation here and there makes things
complicated.

Like other clk_core members, allocate core->parents in clk_register()
and let it fail in case of memory shortage.  If we cannot allocate
such a small piece of memory, the system is already insane.  There is
no point to postpone the memory allocation.

Also, allocate core->parents regardless of core->num_parents.  We want
it even if core->num_parents == 1 because clk_fetch_parent_index()
might be called against the clk_core with a single parent.

If core->num_parents == 0, core->parents is set to ZERO_SIZE_PTR. It
is harmless because no access happens to core->parents in such a case.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:46 -08:00
Masahiro Yamada
3a6e845451 clk: change sizeof(struct clk *) to sizeof(*core->parents)
Now, the clock parent is not "struct clk *", but "struct clk_core *".
Of course, the size of a pointer is always same, but strictly speaking,
sizeof(struct clk *) should be sizeof(struct clk_core *) here.

This mismatch happened when we split the structure into struct clk
and struct clk_core.  For the potential possibility of future renaming,
sizeof(*core->parents) would be better.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:43 -08:00
Masahiro Yamada
027f942ce4 clk: remove unnecessary !core->parents conditional
This if-block has been here since the introduction of the common
clock framework.  Now no clock drivers are statically initialized.
core->parent is always NULL at this point.  Drop the redundant
check and the confusing comment.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:39 -08:00
Masahiro Yamada
be45ebf25f clk: rename __clk_init() into __clk_core_init()
Now this function takes clk_core as its argument.  __clk_core_init()
would be more suitable for the name of this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:36 -08:00
Masahiro Yamada
d35c80c248 clk: change the argument of __clk_init() into pointer to clk_core
The argument clk_user is used only for the clk_user->core.  The rest
of this function only takes care of clk_core.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:32 -08:00
Masahiro Yamada
d9e743408e clk: remove unused first argument of __clk_init()
The "struct device *dev" is not used at all in this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:28 -08:00
Michael Turquette
a915e30dd2 Merge branch 'clk-rockchip' into clk-next 2015-12-23 13:08:56 -08:00
Heiko Stuebner
2eb8c7104c clk: add flag for clocks that need to be enabled on rate changes
Some clocks need to be enabled to accept rate changes. This patch adds a
new flag CLK_SET_RATE_UNGATE that lets clk_change_rate enable the clock
before trying to change the rate and disable it again afterwards.
This of course doesn't effect clocks that are already running at that
point, as their refcount will only temporarily increase.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-23 12:57:31 -08:00
Masahiro Yamada
8da411cc19 clk: let of_clk_get_parent_name() fail for invalid clock-indices
Currently, of_clk_get_parent_name() returns a wrong parent clock name
when "clock-indices" property exists and the target index is not
found in the property.  In this case, NULL should be returned.

For example,

        oscillator {
                compatible = "myclocktype";
                #clock-cells = <1>;
                clock-indices = <1>, <3>;
                clock-output-names = "clka", "clkb";
        };

        consumer {
                compatible = "myclockconsumer";
                clocks = <&oscillator 0>, <&oscillator 1>;
        };

Currently, of_clk_get_parent_name(consumer_np, 0) returns "clka"
(and of_clk_get_parent_name(consumer_np, 1) also returns "clka",
this is correct).   Because the "clock-indices" in the clock parent
does not contain <0>, of_clk_get_parent_name(consumer_np, 0) should
return NULL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-12-02 22:34:43 -08:00
Masahiro Yamada
198bb59493 clk: fix a typo in comment block of clk_notifier_register()
The word "cases" is doubled.  Keep decent forms for the following
lines.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-30 11:36:07 -08:00
Geert Uytterhoeven
3fe003f944 clk: Spelling s/derefing/dereferencing/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 11:17:55 -08:00
Masahiro Yamada
c1de13574d clk: use IS_ERR_OR_NULL(hw) instead of !hw || IS_ERR(hw)
This minor refactoring does not change the function behavior.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 09:20:54 -08:00
Masahiro Yamada
c736c4e11e clk: remove redundant negative index check in of_clk_get_parent_name()
This if-block can be dropped because the of_parse_phandle_with_args()
in the following line returns -EINVAL for negative index.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 09:18:24 -08:00
Joachim Eastwood
be68bf8831 clk: Add clk_hw_is_enabled() for use by clk providers
Add clk_hw_is_enabled() to the provider APIs so clk providers can
use a struct clk_hw instead of a struct clk to check if a clk is
enabled or not.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-26 12:36:55 -07:00
Julia Lawall
6bc9d9d62c clk: add missing of_node_put
for_each_matching_node_and_match performs an of_node_get on each iteration,
so a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression e1,e2,e;
local idexpression np;
@@

 for_each_matching_node_and_match(np, e1, e2) {
   ... when != of_node_put(np)
       when != e = np
(
   return np;
|
+  of_node_put(np);
?  return ...;
)
   ...
 }
// </smpl>

Besides the problem identified by the semantic patch, this patch adds an
of_node_get in front of saving np in a field of parent, to account for the
fact that this value will be put on going on to the next element in the
iteration, and then adds of_node_puts in the two loops where the parent
pointer can be freed.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-21 16:16:32 -07:00
Geert Uytterhoeven
b76281cb97 clk: Make clk input parameter of __clk_get_name() const
When calling __clk_get_name() on a const clock:

    warning: passing argument 1 of '__clk_get_name' discards 'const' qualifier from pointer target type
    include/linux/clk-provider.h:613:13: note: expected 'struct clk *' but argument is of type 'const struct clk *'

__clk_get_name() does not modify the passed clock, hence make it const.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16 11:56:19 -07:00
Geert Uytterhoeven
7e96353c3f clk: Use %u to format unsigned int in of_clk_src_onecell_get()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16 11:49:01 -07:00
Stephen Boyd
0a4807c2f9 clk: Make of_clk_get_parent_name() robust with #clock-cells = 1
If a clock provider has #clock-cells = 1 and we call
of_clk_get_parent_name() on it we may end up returning the name
of the provider node if the provider doesn't have a
clock-output-names property. This doesn't make sense, especially
when you consider that calling of_clk_get_parent_name() on such a
node with different indices will return the same name each time.

Let's try getting the clock from the framework via of_clk_get()
instead, and only fallback to the node name if we have a provider
with #clock-cells = 0. This way, we can't hand out the same name
for different clocks when we don't actually know their names.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-15 16:17:03 -07:00
Stephen Boyd
ab5c342992 Merge branch 'clk-fixes' into clk-next
* clk-fixes:
  drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
  clk: check for invalid parent index of orphans in __clk_init()
2015-09-17 12:28:41 -07:00
Javier Martinez Canillas
90c53547fc clk: Remove unneeded semicolons
There are cleary typo errors so can be removed.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-17 11:15:14 -07:00
Mans Rullgard
9054a31d60 clk: check for invalid parent index of orphans in __clk_init()
If a mux clock is initialised (by hardware or firmware) with an
invalid parent, its ->get_parent() can return an out of range
index.  For example, the generic mux clock attempts to return
-EINVAL, which due to the u8 return type ends up a rather large
number.  Using this index with the parent_names[] array results
in an invalid pointer and (usually) a crash in the following
strcmp().

This patch adds a check for the parent index being in range,
ignoring clocks reporting invalid values.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Tested-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-16 15:35:18 -07:00
Dong Aisheng
c660b2ebb2 clk: remove duplicated code with __clk_set_parent_after
__clk_set_parent_after() actually used the second argument then we
could put this duplicate logic in there and call it with a different
order of arguments in the success vs. error paths in this function.

Cc: Mike Turquette <mturquette@linaro.org>
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:13 -07:00
Stephen Boyd
e7df6f6e21 clk: Constify clk_hw argument to provider APIs
We don't modify the clk_hw argument in these functions, so it's
safe to mark it as const.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:11 -07:00
Stephen Boyd
fc4a05d4b0 clk: Remove unused provider APIs
Remove these APIs now that we've converted all users to the
replacement struct clk_hw based versions.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:02 -07:00
Stephen Boyd
1a9c069cb2 clk: Add clk_hw_*() APIs for use by clk providers
clk providers shouldn't need to use the consumer APIs (clk.h).
Add provider APIs to replace the __clk_*() APIs that take a
struct clk_hw as their first argument instead of a struct clk.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:42 -07:00
Heiko Stuebner
e6500344ed clk: track the orphan status of clocks and their children
While children of orphan clocks are not carried in the orphan-list itself,
they're nevertheless orphans in their own right as they also don't have an
input-rate available. To ease tracking if a clock is an orphan or has an
orphan in its parent path introduce an orphan field into struct clk and
update it and the fields in child-clocks when a clock gets added or removed
from the orphan-list.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: kernel@pengutronix.de
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Chao Xie <chao.xie@marvell.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Barry Song <baohua@kernel.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com>
Cc: emilio@elopez.com.ar
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Michal Simek <michal.simek@xilinx.com>
[sboyd@codeaurora.org: s/clk/core/ in new function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-12 00:59:18 -07:00
Stephen Boyd
a57aa18539 clk: Silence warnings about lock imbalances
The recursive spinlock implementation trips up sparse and it
complains that these functions have lock imbalances. That isn't
really true though, so add some __acquires() and __releases()
information so that sparse is quiet.

drivers/clk/clk.c:116:22: warning: context imbalance in 'clk_enable_lock' - wrong count at exit
drivers/clk/clk.c:141:9: warning: context imbalance in 'clk_enable_unlock' - unexpected unlock

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:59:30 -07:00
Stephen Boyd
9cfad9bc47 Merge branch 'cleanup-clk-h-includes' into clk-next
* cleanup-clk-h-includes: (62 commits)
  clk: Remove clk.h from clk-provider.h
  clk: h8300: Remove clk.h and clkdev.h includes
  clk: at91: Include clk.h and slab.h
  clk: ti: Switch clk-provider.h include to clk.h
  clk: pistachio: Include clk.h
  clk: ingenic: Include clk.h
  clk: si570: Include clk.h
  clk: moxart: Include clk.h
  clk: cdce925: Include clk.h
  clk: Include clk.h in clk.c
  clk: zynq: Include clk.h
  clk: ti: Include clk.h
  clk: sunxi: Include clk.h and remove unused clkdev.h includes
  clk: st: Include clk.h
  clk: qcom: Include clk.h
  clk: highbank: Include clk.h
  clk: bcm: Include clk.h
  clk: versatile: Remove clk.h and clkdev.h includes
  clk: ux500: Remove clk.h and clkdev.h includes
  clk: tegra: Properly include clk.h
  ...
2015-07-28 11:59:09 -07:00
Stephen Boyd
9783c0d985 clk: Allow providers to configure min/max rates
clk providers are using the consumer APIs to set min/max rates on
the clock they're providing. To encourage clk providers to move
away from the consumer APIs, add a provider API to set the
min/max rate of a clock. The assumption is that this is done
before the clock can be requested via clk_get() and that the
clock rate is already within the boundaries of the min/max that's
configured.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:58:50 -07:00
Stephen Boyd
19aab27308 Merge branch 'clk-determine-rate-struct' into clk-next
* clk-determine-rate-struct:
  clk: fix some determine_rate implementations
  clk: change clk_ops' ->determine_rate() prototype
2015-07-28 11:51:30 -07:00
Boris Brezillon
57d866e606 clk: fix some determine_rate implementations
Some determine_rate implementations are not returning an error
when they failed to adapt the rate according to the rate request.
Fix them so that they return an error instead of silently
returning 0.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:13:32 -07:00
Boris Brezillon
0817b62cc0 clk: change clk_ops' ->determine_rate() prototype
Clock rates are stored in an unsigned long field, but ->determine_rate()
(which returns a rounded rate from a requested one) returns a long
value (errors are reported using negative error codes), which can lead
to long overflow if the clock rate exceed 2Ghz.

Change ->determine_rate() prototype to return 0 or an error code, and pass
a pointer to a clk_rate_request structure containing the expected target
rate and the rate constraints imposed by clk users.

The clk_rate_request structure might be extended in the future to contain
other kind of constraints like the rounding policy, the maximum clock
inaccuracy or other things that are not yet supported by the CCF
(power consumption constraints ?).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
[sboyd@codeaurora.org: Fix parent dereference problem in
__clk_determine_rate()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
[sboyd@codeaurora.org: Folded in fix from Heiko for fixed-rate
clocks without parents or a rate determining op]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:12:01 -07:00
Stephen Boyd
3c37311730 clk: Include clk.h in clk.c
This file implements the clk API and so it should include clk.h
directly instead of indirectly including it through
clk-provider.h.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-20 11:11:30 -07:00
Stephen Boyd
2573a02aa5 clk: Move clk_provider_list to scope of function using it
The list isn't used after of_clk_init() is called, so we don't
need to keep an empty list around after init. Put the list on the
stack.

Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:05 -07:00
Stephen Boyd
2e3b19f137 clk: Check for allocation errors in of_clk_init()
Dan Carpenter reports that we don't check the allocation here for
failure. Add a failure check and free any previously allocated
providers from the clk_provider_list.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:03 -07:00
Michael Turquette
2cd7b04328 clk: tegra: Changes for v4.2-rc1
This contains the EMC clock driver that's been exhaustively reviewed and
 tested. It also includes a change to the clock core that allows a clock
 provider to perform low-level reparenting of clocks. This is required by
 the EMC clock driver because the reparenting needs to be done at a very
 specific point in time during the EMC frequency switch.
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Merge tag 'tegra-for-4.2-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next

clk: tegra: Changes for v4.2-rc1

This contains the EMC clock driver that's been exhaustively reviewed and
tested. It also includes a change to the clock core that allows a clock
provider to perform low-level reparenting of clocks. This is required by
the EMC clock driver because the reparenting needs to be done at a very
specific point in time during the EMC frequency switch.
2015-06-20 13:29:48 -07:00
Michael Turquette
85e88fab13 Merge branch 'clk-exynos-cpu-clk' into clk-next
Folded into this merge commit is a build error fix: s/clk/core in
clk_change_rate due to the new struct clk_core
2015-06-20 13:26:40 -07:00
Bartlomiej Zolnierkiewicz
d8d919879e clk: add CLK_RECALC_NEW_RATES clock flag for Exynos cpu clock support
This flag is needed to fix the issue with wrong dividers being setup
by Common Clock Framework when using the new Exynos cpu clock support.

The issue happens because clk_core_set_rate_nolock()  calls
clk_calc_new_rates(clk, rate) before both pre/post clock notifiers have
a chance to run.  In case of Exynos cpu clock support pre/post clock
notifiers are registered for mout_apll clock which is a parent of armclk
cpu clock and dividers are modified in both pre and post clock notifier.
This results in wrong dividers values being later programmed by
clk_change_rate(top).  To workaround the problem CLK_RECALC_NEW_RATES
flag is added and it is set for mout_apll clock later so the correct
divider values are re-calculated after both pre and post clock notifiers
had run.

For example when using "performance" governor on Exynos4210 Origen board
the cpufreq-dt driver requests to change the frequency from 1000MHz to
1200MHz and after the change state of the relevant clocks is following:

Without use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 300000000
                                 div_hpm rate: 300000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 300000000
                                 div_pclk_dbg rate: 150000000
                 sclk_apll rate: 1200000000
                         sclk_apll_div_2 rate: 600000000

With use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 200000000
                                 div_hpm rate: 200000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 240000000
                                 div_pclk_dbg rate: 120000000
                 sclk_apll rate: 150000000
                         sclk_apll_div_2 rate: 75000000

Without this change cpufreq-dt driver showed ~10 mA larger energy
consumption when compared to cpufreq-exynos one when "performance"
cpufreq governor was used on Exynos4210 SoC based Origen board.

This issue was probably meant to be workarounded by use of
CLK_GET_RATE_NOCACHE and CLK_DIVIDER_READ_ONLY clock flags in
the original Exynos cpu clock patchset (in "[PATCH v12 6/6] clk:
samsung: remove unused clock aliases and update clock flags" patch)
but usage of these flags is not sufficient to fix the issue observed.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-06-20 12:17:41 -07:00
Maxime Coquelin
8c9a8a8f71 clk: Move debug_node field under DEBUG_FS flag in struct clk_core
The debug_node field is only used when DEBUG_FS config is selected,
so declare it only if DEBUG_FS is selected.

Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-10 14:21:22 -07:00
Dinh Nguyen
2e61dfb360 clk: of: helper for filling parent clock array and return num of parents
Sprinkled all through the platform clock drivers are code like this to
fill the clock parent array:

for (i = 0; i < num_parents; ++i)
	parent_names[i] = of_clk_get_parent_name(np, i);

The of_clk_parent_fill() will do the same as the code above, and while
at it, return the number of parents as well since the logic of the
function is to the walk the clock node to look for the parent.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
[sboyd@codeaurora.org: Fixed kernel-doc]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-05 18:10:33 -07:00
Shailendra Verma
a59a516398 clk: Fix typo in clk_register() comment
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-20 15:44:32 -07:00
Stephen Boyd
562ef0b098 clk: Silence sparse warnings about __clk_{get,put}()
drivers/clk/clk.c:2700:5: warning: symbol '__clk_get' was not declared. Should it be static?
drivers/clk/clk.c:2713:6: warning: symbol '__clk_put' was not declared. Should it be static?

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-14 17:11:17 -07:00
Tomeu Vizoso
42c86547f4 clk: Expose clk_hw_reparent() to providers
To be used by clock implementations for switching to a new parent during
rate change.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-05-13 15:17:08 +02:00
Stephen Boyd
a633472519 clk: Add some more lockdep assertions
We don't check to make sure the enable_lock is held across
enable/disable and we don't check if the prepare_lock is held
across prepare/unprepare. Add some asserts to catch any future
locking problems.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-07 11:32:54 -07:00
Stephen Boyd
18e70efe3e Merge branch 'clk-fixes' into clk-next 2015-05-07 11:32:49 -07:00
Felipe Balbi
70e9f4dde0 clk: add newline character after dumping all clocks
clk_dump() will dump data about all clocks in JSON
format, but it misses a newline character at the
end of the JSON string. This patch adds that missing
newline character.

Signed-off-by: Felipe Balbi <balbi@ti.com>
[sboyd@codeaurora.org: Squelch checkpatch with seq_puts()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-07 11:32:37 -07:00
Dong Aisheng
d2a5d46b16 clk: add missing lock when call clk_core_enable in clk_set_parent
Before commit 035a61c314 ("clk: Make clk API return per-user
struct clk instances") we acquired the enable_lock in
__clk_set_parent_{before,after}() by means of calling
clk_enable(). After commit 035a61c314 we use clk_core_enable()
in place of the clk_enable(), and clk_core_enable() doesn't
acquire the enable_lock. This opens up a race condition between
clk_set_parent() and clk_enable(). Fix it.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-06 16:58:53 -07:00
Stefan Wahren
7cb81136d2 clk: Fix JSON output in debugfs
key/value pairs in a JSON object must be separated by a comma.
After adding the properties "accuracy" and "phase" the JSON output
of /sys/kernel/debug/clk/clk_dump is invalid.

So add the missing commas to fix it.

Fixes: 5279fc402a ("clk: add clk accuracy retrieval support")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
[sboyd@codeaurora.org: Added comment in function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-01 18:25:08 -07:00
Stephen Boyd
6e5ab41b10 clk: Update some comments to reflect reality
The debugfs clk directory no longer expresses a clk tree. Update
the comments around that apporiately. Also drop comments about
prepare locks needing to be held as we have the proper
annotations with lockdep_assert_held().

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:41 -07:00
Stephen Boyd
4dff95dc94 clk: Remove forward declared function prototypes
Move the code around so that we don't need to declare function
prototypes at the start of the file. Simplify
clk_core_is_prepared() and clk_core_is_enabled() too to make the
diff easier to read.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:39 -07:00
Stephen Boyd
1f3e198342 clk: Remove impossible if condition in clk_core_get_phase()
This condition can't ever be true because this function is static
and it's always called with a non-NULL pointer.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:37 -07:00
Stephen Boyd
d7d131512b clk: Drop unnecessary OOM prints
We don't need to print error messages when allocations fail.
We'll get a nice backtrace in such situations anyway.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:35 -07:00
Dong Aisheng
864e160ae5 clk: Squash __clk_{enable,disable}() into callers
These functions are only used in one place. Let's squash them
into their respective callers to save some lines.

Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
[sboyd@codeaurora.org: Redo commit text, add NULL check in
clk_enable()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:33 -07:00
Stephen Boyd
d6968fca78 clk: s/clk/core/ for struct clk_core
While introducing struct clk_core we tried to minimize the diff
by changing the type of 'clk' variables from struct clk to struct
clk_core without changing the names of the variables. Now that
the split is complete, the code is slightly confusing when it
mixes variables called 'clk' and variables called 'core' that are
of the same type struct clk_core. Let's be consistent and use
'core' everywhere we have a struct clk_core pointer and 'clk'
when we have a struct clk pointer.

Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:24 -07:00
Boris Brezillon
03bc10ab5b clk: check ->determine/round_rate() return value in clk_calc_new_rates
->determine_rate() and ->round_rate() can return the closest rate to the
requested one or an error code.
clk_calc_new_rates is assuming these functions can't return a negative
value, which leads to a undefined behavior when the clk implementation
returns such an error code.
Fix this by returning NULL in case ->determine_rate() or ->round_rate()
returned an error code.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-04-12 21:09:49 -07:00
Stephen Boyd
5cf065f556 Merge branch 'clk-fixes' into clk-next 2015-03-12 12:20:36 -07:00
Stephen Boyd
306c342f9c clk: Replace of_clk_get_by_clkspec() with of_clk_get_from_provider()
of_clk_get_by_clkspec() has the same function signature as
of_clk_get_from_provider()

 struct clk *of_clk_get_by_clkspec(struct of_phandle_args
 *clkspec)
 struct clk *of_clk_get_from_provider(struct of_phandle_args
 *clkspec)

except of_clk_get_by_clkspec() checks to make sure clkspec is not
NULL. Let's remove of_clk_get_by_clkspec() and replace the
callers of it (clkconf.c) with of_clk_get_from_provider().

Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12 12:20:34 -07:00
Stephen Boyd
50595f8b9e clk: Rename child_node to clks_node to avoid confusion
The child_node member of struct clk is named the same as the
child_node member of struct clk_core. Let's rename the struct
clk's member to clks_node to avoid getting confused with the
child_node member of struct clk_core and to match the name of the
list head, clks.

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Alban Browaeys <alban.browaeys@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12 12:20:32 -07:00
Stephen Boyd
b61c43c09f clk: clk_set_parent() with current parent shouldn't fail
If a driver calls clk_set_parent(clk, parent) and parent is the
current parent of clk we shouldn't fail in any case.
Unfortunately if clk is a read-only mux we return -ENOSYS
because we think we can't change the parent, except for in this
special case where we don't actually need to change the parent at
all. Return 0 in such a situation.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:53 -07:00
Stephen Boyd
dfc202ead3 clk: Add tracepoints for hardware operations
It's useful to have tracepoints around operations that change the
hardware state so that we can debug clock hardware performance
and operations. Four basic types of events are supported: on/off
events for enable, disable, prepare, unprepare that only record
an event and a clock name, rate changing events for
clk_set_{min_,max_}rate{_range}(), phase changing events for
clk_set_phase() and parent changing events for clk_set_parent().

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:51 -07:00
Stephen Boyd
08b9575660 clk: Missing set_phase op is an error
If a clock's clk_ops doesn't have the set_phase op set we should
return an error from clk_set_phase(). This way clock consumers
know that when they tried to set a phase it didn't work, as
opposed to the current behavior where the return value is 0
meaning success.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:49 -07:00
Krzysztof Kozlowski
496eadf821 clk: Use lockdep asserts to find missing hold of prepare_lock
Add lockdep asserts for holding the prepare_lock to all functions
marking this as a requirement in description. Add this to private and
exported functions so all locking misuse could be detected during
debugging.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:45 -07:00
Michael Turquette
3d3801effd clk: introduce clk_is_match
Some drivers compare struct clk pointers as a means of knowing
if the two pointers reference the same clock hardware. This behavior is
dubious (drivers must not dereference struct clk), but did not cause any
regressions until the per-user struct clk patch was merged. Now the test
for matching clk's will always fail with per-user struct clk's.

clk_is_match is introduced to fix the regression and prevent drivers
from comparing the pointers manually.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: const arguments to clk_is_match() and
remove unnecessary ternary operation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-11 15:56:59 -07:00
Julia Lawall
f55ac0655a clk: don't export static symbol
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
type T;
identifier f;
@@

static T f (...) { ... }

@@
identifier r.f;
declarer name EXPORT_SYMBOL_GPL;
@@

-EXPORT_SYMBOL_GPL(f);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Fixes: 035a61c314 "clk: Make clk API return per-user struct clk instances"
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-11 15:53:18 -07:00
Linus Torvalds
18a8d49973 The clock framework changes for 3.20 contain the usual driver additions,
enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
 devices. Additionaly the framework core underwent a bit of surgery with
 two major changes. The boundary between the clock core and clock
 providers (e.g clock drivers) is now more well defined with dedicated
 provider helper functions. struct clk no longer maps 1:1 with the
 hardware clock but is a true per-user cookie which helps us tracker
 users of hardware clocks and debug bad behavior. The second major change
 is the addition of rate constraints for clocks. Rate ranges are now
 supported which are analogous to the voltage ranges in the regulator
 framework. Unfortunately these changes to the core created some
 breakeage. We think we fixed it all up but for this reason there are
 lots of last minute commits trying to undo the damage.
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Merge tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux

Pull clock framework updates from Mike Turquette:
 "The clock framework changes contain the usual driver additions,
  enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
  devices.

  Additionally the framework core underwent a bit of surgery with two
  major changes:

   - The boundary between the clock core and clock providers (e.g clock
     drivers) is now more well defined with dedicated provider helper
     functions.  struct clk no longer maps 1:1 with the hardware clock
     but is a true per-user cookie which helps us tracker users of
     hardware clocks and debug bad behavior.

   - The addition of rate constraints for clocks.  Rate ranges are now
     supported which are analogous to the voltage ranges in the
     regulator framework.

  Unfortunately these changes to the core created some breakeage.  We
  think we fixed it all up but for this reason there are lots of last
  minute commits trying to undo the damage"

* tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits)
  clk: Only recalculate the rate if needed
  Revert "clk: mxs: Fix invalid 32-bit access to frac registers"
  clk: qoriq: Add support for the platform PLL
  powerpc/corenet: Enable CLK_QORIQ
  clk: Replace explicit clk assignment with __clk_hw_set_clk
  clk: Add __clk_hw_set_clk helper function
  clk: Don't dereference parent clock if is NULL
  MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr
  clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
  clk: shmobile: div6: Avoid division by zero in .round_rate()
  clk: mxs: Fix invalid 32-bit access to frac registers
  clk: omap: compile legacy omap3 clocks conditionally
  clkdev: Export clk_register_clkdev
  clk: Add rate constraints to clocks
  clk: remove clk-private.h
  pci: xgene: do not use clk-private.h
  arm: omap2+ remove dead clock code
  clk: Make clk API return per-user struct clk instances
  clk: tegra: Define PLLD_DSI and remove dsia(b)_mux
  clk: tegra: Add support for the Tegra132 CAR IP block
  ...
2015-02-21 12:30:30 -08:00
Tomeu Vizoso
ec02ace8ca clk: Only recalculate the rate if needed
We don't really need to recalculate the effective rate of a clock when a
per-user clock is removed, if the constraints of the later aren't
limiting the requested rate.

This was causing problems with clocks that never had a rate set before,
as rate_req would be zero. Though this could be considered a bug in the
implementation of those clocks, this should be checked somewhere else.

Fixes: 1c8e600440 ("clk: Add rate constraints to clocks")
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-19 19:29:19 -08:00
Javier Martinez Canillas
9e0ad7d28a clk: Don't dereference parent clock if is NULL
The clock passed as an argument to clk_mux_determine_rate_flags()
has the CLK_SET_RATE_PARENT flag set but it has no parent, then a
NULL pointer will tried to be dereferenced.

This shouldn't happen since setting that flag for a clock with no
parent is a bug but the core should be robust to handle that case.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-18 09:40:01 -08:00
Andrzej Hajda
612936f212 clk: convert clock name allocations to kstrdup_const
Clock subsystem frequently performs duplication of strings located in
read-only memory section.  Replacing kstrdup by kstrdup_const allows to
avoid such operations.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:36 -08:00
Stephen Boyd
73e0e496af clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
of_clk_get_by_clkspec() returns a struct clk pointer but it
doesn't create a new handle for the consumers when we're using
the common clock framework. Instead it just returns whatever the
clk provider hands out. When the consumers go to call clk_put()
we get an Oops.

Unable to handle kernel paging request at virtual address 00200200
pgd = c0004000
[00200200] *pgd=00000000
Internal error: Oops: 805 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
task: ee00b000 ti: ee088000 task.ti: ee088000
PC is at __clk_put+0x24/0xd0
LR is at clk_prepare_lock+0xc/0xec
pc : [<c03eef38>]    lr : [<c03ec1f4>]    psr: 20000153
sp : ee089de8  ip : 00000000  fp : 00000000
r10: ee02f480  r9 : 00000001  r8 : 00000000
r7 : ee031cc0  r6 : ee089e08  r5 : 00000000  r4 : ee02f480
r3 : 00100100  r2 : 00200200  r1 : 0000091e  r0 : 00000001
Flags: nzCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5387d  Table: 4000404a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xee088238)
Stack: (0xee089de8 to 0xee08a000)
9de0:                   ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001
9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000
9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0
9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000
9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10
9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000
9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0
9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88
9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0
9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000
9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88
9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006
9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006
9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000
9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0
[<c03eef38>] (__clk_put) from [<c03f0ec8>] (of_clk_set_defaults+0xe0/0x2c0)
[<c03f0ec8>] (of_clk_set_defaults) from [<c02c3124>] (platform_drv_probe+0x18/0xa4)
[<c02c3124>] (platform_drv_probe) from [<c02c1d0c>] (driver_probe_device+0x10c/0x22c)
[<c02c1d0c>] (driver_probe_device) from [<c02c1eb8>] (__driver_attach+0x8c/0x90)
[<c02c1eb8>] (__driver_attach) from [<c02c0544>] (bus_for_each_dev+0x54/0x88)
[<c02c0544>] (bus_for_each_dev) from [<c02c150c>] (bus_add_driver+0xd4/0x1d0)
[<c02c150c>] (bus_add_driver) from [<c02c24e0>] (driver_register+0x78/0xf4)
[<c02c24e0>] (driver_register) from [<c07091f0>] (fimc_md_init+0x14/0x30)
[<c07091f0>] (fimc_md_init) from [<c0008944>] (do_one_initcall+0x80/0x1d0)
[<c0008944>] (do_one_initcall) from [<c06edd64>] (kernel_init_freeable+0x108/0x1d4)
[<c06edd64>] (kernel_init_freeable) from [<c04e64fc>] (kernel_init+0x8/0xec)
[<c04e64fc>] (kernel_init) from [<c000e838>] (ret_from_fork+0x14/0x3c)
Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000)

Let's create a per-user handle here so that clk_put() can
properly unlink it and free the handle. Now that we allocate a
clk structure here we need to free it if __clk_get() fails so
bury the __clk_get() call in __of_clk_get_from_provider(). We
need to handle the same problem in clk_get_sys() so export
__clk_free_clk() to clkdev.c and do the same thing, except let's
use a union to make this code #ifdef free.

This fixes the above crash, properly calls __clk_get() when
of_clk_get_from_provider() is called, and cleans up the clk
structure on the error path of clk_get_sys().

Fixes: 035a61c314 "clk: Make clk API return per-user struct clk instances"
Reported-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reported-by: Alban Browaeys <alban.browaeys@gmail.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Alban Browaeys <prahal@yahoo.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-06 17:53:20 -08:00
Tomeu Vizoso
1c8e600440 clk: Add rate constraints to clocks
Adds a way for clock consumers to set maximum and minimum rates. This
can be used for thermal drivers to set minimum rates, or by misc.
drivers to set maximum rates to assure a minimum performance level.

Changes the signature of the determine_rate callback by adding the
parameters min_rate and max_rate.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[sboyd@codeaurora.org: set req_rate in __clk_init]
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate
                        migrated clk-private.h changes to clk.c]
2015-02-02 14:23:42 -08:00
Michael Turquette
b09d6d9910 clk: remove clk-private.h
Private clock framework data structures should be private, surprisingly.

Now that all platforms and drivers have been updated to remove static
initializations of struct clk and struct clk_core objects and all
references to clk-private.h have been removed we can move the
definitions of these structures into drivers/clk/clk.c and delete the
header.

Additionally the ugly DEFINE_CLK macros have been removed. Those were
used for static definitions of struct clk objects. That practice is no
longer allowed.

Finally __clk_init is staticized as it is no longer declared in any
header.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-02 14:23:41 -08:00
Tomeu Vizoso
035a61c314 clk: Make clk API return per-user struct clk instances
Moves clock state to struct clk_core, but takes care to change as little API as
possible.

struct clk_hw still has a pointer to a struct clk, which is the
implementation's per-user clk instance, for backwards compatibility.

The struct clk that clk_get_parent() returns isn't owned by the caller, but by
the clock implementation, so the former shouldn't call clk_put() on it.

Because some boards in mach-omap2 still register clocks statically, their clock
registration had to be updated to take into account that the clock information
is stored in struct clk_core now.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: adapted clk_has_parent to struct clk_core
                        applied OMAP3+ DPLL fix from Tero & Tony]
2015-02-02 14:22:19 -08:00