Commit Graph

21 Commits

Author SHA1 Message Date
Mark Rutland
6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
Jon Hunter
7e10cf7436 soc/tegra: Move Tegra flowctrl driver
The flowctrl driver is required for both ARM and ARM64 Tegra devices
and in order to enable support for it for ARM64, move the Tegra flowctrl
driver into drivers/soc/tegra.

By moving the flowctrl driver, tegra_flowctrl_init() is now called by
via an early initcall and to prevent this function from attempting to
mapping IO space for a non-Tegra device, a test for 'soc_is_tegra()'
is also added.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2017-04-04 15:48:04 +02:00
Thierry Reding
755c47ed94 ARM: tegra: cpuidle: Add missing cpuidle.h include
Some of the functions implemented are flagged as not having a prototype
defined when building with W=1. Include the header to avoid these build
warnings and add a prototype as well as a dummy implementation for the
tegra_cpuidle_pcie_irqs_in_use() function.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-10 16:17:59 +02:00
Dmitry Osipenko
4d48edb3c3 ARM: tegra20: Store CPU "resettable" status in IRAM
Commit 7232398abc ("ARM: tegra: Convert PMC to a driver") changed tegra_resume()
location storing from late to early and, as a result, broke suspend on Tegra20.
PMC scratch register 41 is used by tegra LP1 resume code for retrieving stored
physical memory address of common resume function and in the same time used by
tegra20_cpu_shutdown() (shared by Tegra20 cpuidle driver and platform SMP code),
which is storing CPU1 "resettable" status. It implies strict order of scratch
register usage, otherwise resume function address is lost on Tegra20 after
disabling non-boot CPU's on suspend. Fix it by storing "resettable" status in
IRAM instead of PMC scratch register.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Fixes: 7232398abc (ARM: tegra: Convert PMC to a driver)
Cc: <stable@vger.kernel.org> # v3.17+
Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-05-04 12:58:19 +02:00
Linus Torvalds
2481bc7528 Power management and ACPI updates for v4.1-rc1
- Generic PM domains support update including new PM domain
    callbacks to handle device initialization better (Russell King,
    Rafael J Wysocki, Kevin Hilman).
 
  - Unified device properties API update including a new mechanism
    for accessing data provided by platform initialization code
    (Rafael J Wysocki, Adrian Hunter).
 
  - ARM cpuidle update including ARM32/ARM64 handling consolidation
    (Daniel Lezcano).
 
  - intel_idle update including support for the Silvermont Core in
    the Baytrail SOC and for the Airmont Core in the Cherrytrail and
    Braswell SOCs (Len Brown, Mathias Krause).
 
  - New cpufreq driver for Hisilicon ACPU (Leo Yan).
 
  - intel_pstate update including support for the Knights Landing
    chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
 
  - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
 
  - powernv cpufreq driver update (Shilpasri G Bhat).
 
  - devfreq update including Tegra support changes (Tomeu Vizoso,
    MyungJoo Ham, Chanwoo Choi).
 
  - powercap RAPL (Running-Average Power Limit) driver update
    including support for Intel Broadwell server chips (Jacob Pan,
    Mathias Krause).
 
  - ACPI device enumeration update related to the handling of the
    special PRP0001 device ID allowing DT-style 'compatible' property
    to be used for ACPI device identification (Rafael J Wysocki).
 
  - ACPI EC driver update including limited _DEP support (Lan Tianyu,
    Lv Zheng).
 
  - ACPI backlight driver update including a new mechanism to allow
    native backlight handling to be forced on non-Windows 8 systems
    and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
 
  - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
 
  - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
    Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
 
  - Fixes related to suspend-to-idle for the iTCO watchdog driver and
    the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
 
  - PM tracing support for the suspend phase of system suspend/resume
    transitions (Zhonghui Fu).
 
  - Configurable delay for the system suspend/resume testing facility
    (Brian Norris).
 
  - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJVLbO+AAoJEILEb/54YlRx5N4QAJXsmEW1FL2l6mMAyTQkEsVj
 nbqjF9I6aJgYM9+i8GKaZJxpN17SAZ7Ii7aCAXjPwX8AvjT70+gcZr+KDWtPir61
 B75VNVEcUYOR4vOF5Z6rQcQMlhGPkfMOJYXFMahpOG6DdPbVh1x2/tuawfc6IC0V
 a6S/fln6WqHrXQ+8swDSv1KuZsav6+8AQaTlNUQkkuXdY9b3k/3xiy5C2K26APP8
 x1B39iAF810qX6ipnK0gEOC3Vs29dl7hvNmgOVmmkBGVS7+pqTuy5n1/9M12cDRz
 78IQ7DXB0NcSwr5tdrmGVUyH0Q6H9lnD3vO7MJkYwKDh5a/2MiBr2GZc4KHDKDWn
 E1sS27f1Pdn9qnpWLzTcY+yYNV3EEyre56L2fc+sh+Xq9sNOjUah+Y/eAej/IxYD
 XYRf+GAj768yCJgNP+Y3PJES/PRh+0IZ/dn5k0Qq2iYvc8mcObyG6zdQIvCucv/i
 70uV1Z2GWEb31cI9TUV8o5GrMW3D0KI9EsCEEpiFFUnhjNog3AWcerGgFQMHxu7X
 ZnNSzudvek+XJ3NtpbPgTiJAmnMz8bDvBQm3G1LUO2TQdjYTU6YMUHsfzXs8DL6c
 aIMWO4stkVuDtWrlT/hfzIXepliccyXmSP6sbH+zNNCepulXe5C4M2SftaDi4l/B
 uIctXWznvHoGys+EFL+v
 =erd3
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
Thomas Gleixner
a0b4122447 ARM: Tegra: Use explicit broadcast oneshot control function
Replace the clockevents_notify() call with an explicit function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: http://lkml.kernel.org/r/2131111.rjxRLX1eZB@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:44:35 +02:00
Daniel Lezcano
eeebc3bb4d ARM: cpuidle: Remove duplicate header inclusion
The cpu_do_idle() function is always used by the cpuidle drivers.

That led to have each driver including cpuidle.h and proc-fns.h, they are
always paired. That makes a lot of duplicate headers inclusion. Instead of
including both in each .c file, move the proc-fns.h header inclusion in the
cpuidle.h header file directly, so we can save some line of code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2015-03-23 18:03:11 +01:00
Daniel Lezcano
b82b6cca48 cpuidle: Invert CPUIDLE_FLAG_TIME_VALID logic
The only place where the time is invalid is when the ACPI_CSTATE_FFH entry
method is not set. Otherwise for all the drivers, the time can be correctly
measured.

Instead of duplicating the CPUIDLE_FLAG_TIME_VALID flag in all the drivers
for all the states, just invert the logic by replacing it by the flag
CPUIDLE_FLAG_TIME_INVALID, hence we can set this flag only for the acpi idle
driver, remove the former flag from all the drivers and invert the logic with
this flag in the different governor.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-12 21:17:27 +01:00
Thierry Reding
a0524acc94 ARM: tegra: Sort includes alphabetically
If these aren't sorted alphabetically, then the logical choice is to
append new ones, however that creates a lot of potential for conflicts
because every change will then add new includes in the same location.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-07-17 13:29:57 +02:00
Stephen Warren
b4f173752a ARM: tegra: disable LP2 cpuidle state if PCIe is enabled
Tegra20 HW appears to have a bug such that PCIe device interrupts,
whether they are legacy IRQs or MSI, are lost when LP2 is enabled. To
work around this, simply disable LP2 if any PCIe devices with interrupts
are present. Detect this via the IRQ domain map operation. This is
slightly over-conservative; if a device with an interrupt is present but
the driver does not actually use them, LP2 will still be disabled.
However, this is a reasonable trade-off which enables a simpler
workaround.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
2013-08-13 12:07:56 -06:00
Joseph Lo
8f6a0b6528 ARM: tegra: don't pass CPU ID to tegra_{set,clear}_cpu_in_lp2
tegra_{set,clear}_cpu_in_lp2 can easily determine which CPU ID they are
running on; there is no need to pass the CPU ID into those functions.
So, remove their CPU ID function parameter.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-06-05 11:44:58 -06:00
Joseph Lo
bf91add4a0 ARM: tegra: hook tegra_tear_down_cpu function in the PM suspend init function
The tegra_tear_down_cpu was used to cut off the CPU rail for various Tegra
SoCs. Hooking it in the PM suspend init function and making the CPUidle
driver more generic.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-06-05 11:44:54 -06:00
Linus Torvalds
97b1007a29 ARM: arm-soc platform updates for 3.10, part 1
This branch contains platform updates for 3.10. Among the highlights:
 
 - Support for the new Atmel Cortex-A5 based platforms (SAMA5D3)
 - New support for CSR SiRFatlas6 SoCs
 - A handful of updates for NVidia T114 (a.k.a. Tegra 4)
 - A bunch of updates for the shmobile platforms
 - A handful of updates for davinci
 - A few updates for Qualcomm MSM
 - Plus a handful of other patches, defconfig updates, etc.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJRgg+LAAoJEIwa5zzehBx3ePcP/3NUsSOTRQ2SZIVpyjnWOhkf
 RMZiRaVsxrY0BPfDB9E2Vcb6lannKmACTujs/Ux7kJC22BreuFM1PnZoDfhkRuSE
 n/nVB1981XJS82z2uONRSZGlUPSGWYzhTTUDJ0nHiBGmIGf5ctnC0iYWp3As3lv9
 kNY14H7NkwQ4zBVNEMu7WfW8d2IJgqZJgR9xhZPv5fOZ+LlQmK6VaHWTmQtjyea1
 bG1qoJ0dPbfJB4Vnr3a49rBkSJxZUiv8xQucw9+vo+ADRi64M4sZ1Jj2vVyDpqZp
 F4fxBNMVvg7xM0TcBbItFFYJBXlUjeT4z+UI5iYjkbnE7EV9ndFeZXHCWX1qzOSy
 X/nrJKuoe7ISQanBE9SHS9DpDGlkPDO0Mn0vb1f2VUQOY513pt/D1iFYEucZ6WCN
 fWUYtvt5GayidUr55D1U8ssbE0oGt2rizd9x7GUk4KbRVAnUUNopIQAhXrefTrZm
 jfdZNDckJ2F3aq8IPjsKuyJTpe61xD4Wvb3P/pEE3Q8fowPF5WIxXV+qjqHQ9vtt
 Tz4LkP/YdynVFGmhOwz3QZmPaQItaabaYyCcZ5cVCvt5mdxx5VuHYppafhCPJz+V
 KCQpKi1azuIv+sDR+nlGOl6+Ideea3s7TsRudfbmQFp5GsqkqOdJzR9gbbKmJauQ
 4JPpRd+4W8wC8zXQnhVY
 =HXX3
 -----END PGP SIGNATURE-----

Merge tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Olof Johansson:
 "This branch contains part 1 of the platform updates for 3.10.  Among
  the highlights:

   - Support for the new Atmel Cortex-A5 based platforms (SAMA5D3)
   - New support for CSR SiRFatlas6 SoCs
   - A handful of updates for NVidia T114 (a.k.a. Tegra 4)
   - A bunch of updates for the shmobile platforms
   - A handful of updates for davinci
   - A few updates for Qualcomm MSM
   - Plus a handful of other patches, defconfig updates, etc."

* tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (135 commits)
  ARM: tegra: pm: fix build error w/o PM_SLEEP
  ARM: davinci: ensure global variables are declared
  ARM: davinci: sram.c: fix incorrect type in assignment
  ARM: davinci: da8xx dt: make file local symbols static
  ARM: davinci: da8xx: add remoteproc support
  ARM: socfpga: Upgrade clk driver for socfpga to make use of dts clock entries
  ARM: socfpga: Add clock entries into device tree
  ARM: socfpga: Enable soft reset
  ARM: EXYNOS: replace cpumask by the corresponding macro
  ARM: EXYNOS: handle properly the return values
  ARM: EXYNOS: factor out the idle states
  ARM: OMAP4: Enable fix for Cortex-A9 erratas
  ARM: OMAP2+: Export SoC information to userspace
  ARM: OMAP2+: SoC name and revision unification
  ARM: OMAP2+: Move common part of late init into common function
  ARM: tegra: pm: remove duplicated include from pm.c
  ARM: davinci: da850: override mmc DT node device name
  ARM: davinci: da850: add mmc DT entries
  mmc: davinci_mmc: add DT support
  ARM: SAMSUNG: check processor type before cache restoration in resume
  ...
2013-05-02 09:31:45 -07:00
Daniel Lezcano
c5106c9dea ARM: tegra: cpuidle: use init/exit common routine for tegra2
Remove the duplicated code and use the cpuidle common code for initialization.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-23 13:45:23 +02:00
Daniel Lezcano
554c06ba3e cpuidle: remove en_core_tk_irqen flag
The en_core_tk_irqen flag is set in all the cpuidle driver which
means it is not necessary to specify this flag.

Remove the flag and the code related to it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>  # for mach-omap2/*
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-23 13:45:22 +02:00
Daniel Lezcano
0697598db5 ARM: tegra: cpuidle: remove useless initialization
dev->state_count is initialized automatically by
cpuidle_register_device().

When drv->state_count is equal to dev->state_count, no need to init
this field, so removing it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-08 22:20:06 +02:00
Daniel Lezcano
14ad7a119b ARM: tegra2: cpuidle: change driver initialization
Initialize the idle states directly in the driver structure.

That prevents extra structure declaration and memcpy at init time.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-08 22:20:06 +02:00
Joseph Lo
4d82d0587b ARM: tegra: cpuidle: remove redundant parameters for powered-down mode
After the patch series for system suspending support, tegra_idle_lp2_last()
no longer uses its parameters cpu_on_time or cpu_off_time, so remove them.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-04-03 14:45:42 -06:00
Joseph Lo
1d328606c6 ARM: tegra20: cpuidle: apply coupled cpuidle for powered-down mode
The "powered-down" cpuidle mode of Tegra20 needs the CPU0 be the last one
core to go into this mode before other core. The coupled cpuidle framework
can help to sync the MPCore to coupled state then go into "powered-down"
idle mode together. The driver can just assume the MPCore come into
"powered-down" mode at the same time. No need to take care if the CPU_0
goes into this mode along and only can put it into safe idle mode (WFI).

The powered-down state of Tegra20 requires power gating both CPU cores.
When the secondary CPU requests to enter powered-down state, it saves
its own contexts and then enters WFI for waiting CPU0 in the same state.
When the CPU0 requests powered-down state, it attempts to put the secondary
CPU into reset to prevent it from waking up. Then power down both CPUs
together and power off the cpu rail.

Be aware of that, you may see the legacy power state "LP2" in the code
which is exactly the same meaning of "CPU power down".

Based on the work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-01-28 11:20:38 -07:00
Joseph Lo
5c1350bdfc ARM: tegra20: cpuidle: add powered-down state for secondary CPU
The powered-down state of Tegra20 requires power gating both CPU cores.
When the secondary CPU requests to enter powered-down state, it saves
its own contexts and then enters WFI. The Tegra20 had a limition to
power down both CPU cores. The secondary CPU must waits for CPU0 in
powered-down state too. If the secondary CPU be woken up before CPU0
entering powered-down state, then it needs to restore its CPU states
and waits for next chance.

Be aware of that, you may see the legacy power state "LP2" in the code
which is exactly the same meaning of "CPU power down".

Based on the work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-01-28 11:20:38 -07:00
Joseph Lo
0b25e25bef ARM: tegra: cpuidle: separate cpuidle driver for different chips
The different Tegra chips may have different CPU idle states and data.
Individual CPU idle driver make it more easy to maintain.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2012-11-15 15:09:20 -07:00