Since the cache is currently open coded this is more of a win than for
most devices.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Don't use the internal I/O functions directly.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Request the DMA channel in the PCM open callback instead of the hwparams
callback, this allows us to let open fail if no dma channel is available. This
also fixes a bug where the channel will be requested multiple times if hwparams
is called multiple times.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Request the DMA channel in the pcm open callback. This allows us to let open
fail if there is no dma channel available.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Move the call to snd_soc_dai_set_dma_data from the hw_params callback to the
startup callback. This allows us to use the dma data in the pcm driver's open
callback.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Chip designers frequently include things like the enable and disable
controls for algorithms in the register blocks which also hold the
coefficients. Since it's desirable to split out the enable/disable
control from userspace the plain SND_SOC_BYTES() isn't optimal for
these devices.
Add a SND_SOC_BYTES_MASK() which allows a bitmask from the first word
of the block to be excluded from the control. This supports the needs
of devices I've looked at and lets us have a reasonably simple API.
Further controls can be added in future if that's needed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Allow devices to export blocks of registers to the application layer,
intended for use for reading and writing coefficient data which can't
usefully be worked with by the kernel at runtime (for example, due to
requiring complex and expensive calculations or being the results of
callibration procedures). Currently drivers are using platform data to
provide configurations for coefficient blocks which isn't at all
convenient for runtime management or configuration development.
Currently only devices using regmap are supported, an error will be
generated for any attempt to work with a byte control on a non-regmap
device. There's no fundamental block to other devices so support could
be added if required.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Allow us to build infrastructure which needs to know the size of a value
without requiring regmap based drivers to supply this information to both
ASoC and regmap by asking regmap for the value.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
regmap, allowing them to build further subsystem specific generic
features on top of the regmap.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=KhUJ
-----END PGP SIGNATURE-----
Merge tag 'topic/introspection' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into HEAD
New interfaces to allow other subsystems to gather information about the
regmap, allowing them to build further subsystem specific generic
features on top of the regmap.
Merged into ASoC in order to allow us to implement SND_SOC_BYTES_MASK()
controls which need to know the word size of the underlying registers.
When an external capacitor is connected to MICBIAS2 on devices with
jack detection (which is not required but may be done in some systems)
then the loading may mean that better performance is obtained when
the microphone bias is enabled normally rather than using the low power
mode. Provide platform data allowing systems to indicate if they require
this.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This minimises the chance of any external capacitors that are fitted
being discharged into headphones as they insert.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Replace the printk(KERN_ERR* instances with dev_err in the driver.
While we are here clean up some of the debug messages as well.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The WM8775 is register compatible with the WM8776 so can be supported with
the same driver though it is an ADC only part. Add the device ID to the
WM8776 driver, further updates will be added in the future.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Generic infrastructure based on top of regmap may want to operate on
blocks of data and therefore find it useful to find the size of the
register values. Provide an accessor operation for this.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
SND_PCM is already selected by SND_SOC, there is no need for
SND_IMX_SOC and SND_MXS_SOC to select it again.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This patch supports DMAEngine to FSI driver.
It supports only Tx case at this point.
If platform/cpu doesn't support DMAEngine, FSI driver will
use PIO transfer.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
iQEcBAABAgAGBQJPQDoTAAoJEHm+PkMAQRiGMpYH/ibfyIFBrKMD1v/s9oNvp8rS
c7J7E7mHZOylCHrpIS3lX3ZbOfOe33Ln0Z59f1/TcV4CMMz0NrKYcTC8erj/H/DA
8DRYegiczWKqiXRgktwaZXkJcwXYdOOL1WQYxuzzbZcwRrNBY2QpH7Zu8Bj+TPAy
d4fvJHWdlh4sbWVdQmLRbp04UB9J/Z5/uWmSNvVQjLLdRlD+mEBbt7JjiNY6sUVC
2sJoAs9F3UlHu7VaN+JIhMOGZ3GqOpHGBxN/aWxJ/7GsXdXuAfCrxoPxaAe4xzOa
HndN5ZDyg02Vy5uDeUzj+HJPW3M8L4Q0nwxAYb3ZnQ5tbpu1Q2cHfIBealomWCQ=
=R91X
-----END PGP SIGNATURE-----
Merge tag 'v3.3-rc4' into for-3.4 in order to resolve the conflict
resolved below within the FSI driver and allow the application of the
dmaeengine conversion that depends on this resolution.
Linux 3.3-rc4
Conflicts:
sound/soc/sh/fsi.c
This fixes below build warning:
WARNING: vmlinux.o(.text+0x1e632c): Section mismatch in reference from the function pxa2xx_ac97_probe() to the function .devinit.text:pxa2xx_ac97_hw_probe()
The function pxa2xx_ac97_probe() references
the function __devinit pxa2xx_ac97_hw_probe().
This is often because pxa2xx_ac97_probe lacks a __devinit
annotation or the annotation of pxa2xx_ac97_hw_probe is wrong.
Also rename pxa_ac97_dai to pxa_ac97_dai_driver to fix below build warning:
LD sound/soc/pxa/built-in.o
WARNING: sound/soc/pxa/built-in.o(.data+0x18c): Section mismatch in reference from the variable pxa_ac97_dai to the function .devinit.text:pxa2xx_ac97_probe()
The variable pxa_ac97_dai references
the function __devinit pxa2xx_ac97_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The majority of them are regression fixes for stuff that broke during
the merge 3.3 window.
The notable ones are:
* The at91 ata drivers both broke because of an earlier cleanup patch that
some other patches were based on. Jean-Christophe decided to remove
the legacy at91_ide driver and fix the new-style at91-pata driver while
keeping the cleanup patch. I almost rejected the patches for being too
late and too big but in the end decided to accept them because they
fix a regression.
* A patch fixing build breakage from the sysdev-to-device conversion
colliding with other changes touches a number of mach-s3c files.
* b0654037 "ARM: orion: Fix Orion5x GPIO regression from MPP cleanup"
is a mechanical change that unfortunately touches a lot of lines
that should up in the diffstat.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=QYVn
-----END PGP SIGNATURE-----
Merge tag 'fixes-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
These are the bug fixes that have accumulated since 3.3-rc3 in arm-soc.
The majority of them are regression fixes for stuff that broke during
the merge 3.3 window.
The notable ones are:
* The at91 ata drivers both broke because of an earlier cleanup patch that
some other patches were based on. Jean-Christophe decided to remove
the legacy at91_ide driver and fix the new-style at91-pata driver while
keeping the cleanup patch. I almost rejected the patches for being too
late and too big but in the end decided to accept them because they
fix a regression.
* A patch fixing build breakage from the sysdev-to-device conversion
colliding with other changes touches a number of mach-s3c files.
* b0654037 "ARM: orion: Fix Orion5x GPIO regression from MPP cleanup"
is a mechanical change that unfortunately touches a lot of lines
that should up in the diffstat.
* tag 'fixes-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
ARM: at91: drop ide driver in favor of the pata one
pata/at91: use newly introduced SMC accessors
ARM: at91: add accessor to manage SMC
ARM: at91:rtc/rtc-at91sam9: ioremap register bank
ARM: at91: USB AT91 gadget registration for module
ep93xx: fix build of vision_ep93xx.c
ARM: OMAP2xxx: PM: fix OMAP2xxx-specific UART idle bug in v3.3
ARM: orion: Fix USB phy for orion5x.
ARM: orion: Fix Orion5x GPIO regression from MPP cleanup
ARM: EXYNOS: Add cpu-offset property in gic device tree node
ARM: EXYNOS: Bring exynos4-dt up to date
ARM: OMAP3: cm-t35: fix section mismatch warning
ARM: OMAP2: Fix the OMAP2 only build break seen with 2011+ ARM tool-chains
ARM: tegra: paz00: fix wrong UART port on mini-pcie plug
ARM: tegra: paz00: fix wrong SD1 power gpio
i2c: tegra: Add devexit_p() for remove
ARM: EXYNOS: Correct M-5MOLS sensor clock frequency on Universal C210 board
ARM: EXYNOS: Correct framebuffer window size on Nuri board
ARM: SAMSUNG: Fix missing api-change from subsys_interface change
ARM: EXYNOS: Fix "warning: initialization from incompatible pointer type"
...
1) VETH_INFO_PEER netlink attribute needs to have it's size validated,
from Thomas Graf.
2) 'poll' module option of bnx2x driver crashes the machine, just remove
it. From Michal Schmidt.
3) ks8851_mll driver reads the irq number from two places, but only
initializes one of them, oops. Use only one location and fix this
problem, from Jan Weitzel.
4) Fix buffer overrun and unicast sterring bugs in mellanox mlx4 driver,
from Eugenia Emantayev.
5) Swapped kcalloc() args in RxRPC and mlx4, from Axel Lin.
6) PHY MDIO device name regression fixes from Florian Fainelli.
7) If the wake event IRQ line is different from the netdevice one, we
have to properly route it to the stmmac interrupt handler. From
Francesco Virlinzi.
8) Fix rwlock lock initialization ordering bug in mac80211, from
Mohammed Shafi Shajakhan.
9) TCP lost_cnt can get out of sync, and in fact go negative, in certain
circumstances. Fix the way we specify what sequence range to operate
on in tcp_sacktag_one() to fix this bug. From Neal Cardwell.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
net/ethernet: ks8851_mll fix irq handling
veth: Enforce minimum size of VETH_INFO_PEER
stmmac: update the driver version to Feb 2012 (v2)
stmmac: move hw init in the probe (v2)
stmmac: request_irq when use an ext wake irq line (v2)
stmmac: do not discard frame on dribbling bit assert
ipheth: Add iPhone 4S
mlx4: add unicast steering entries to resource_tracker
mlx4: fix QP tree trashing
mlx4: fix buffer overrun
3c59x: shorten timer period for slave devices
netpoll: netpoll_poll_dev() should access dev->flags
RxRPC: Fix kcalloc parameters swapped
bnx2x: remove the 'poll' module option
tcp: fix tcp_shifted_skb() adjustment of lost_cnt_hint for FACK
ks8851: Fix NOHZ local_softirq_pending 08 warning
bnx2x: fix bnx2x_storm_stats_update() on big endian
ixp4xx-eth: fix PHY name to match MDIO bus name
octeon: fix PHY name to match MDIO bus name
fec: fix PHY name to match fixed MDIO bus name
...
method for register cache initialisation is used. Only affects a fairly
small proportion of users that both don't use explicit register defaults
and do use the cache.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=pU4C
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Fixes a bootstrapping issue for some registers when a less commonly used
method for register cache initialisation is used. Only affects a fairly
small proportion of users that both don't use explicit register defaults
and do use the cache.
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: Fix cache defaults initialization from raw cache defaults
and also fixes stale inode mode bits on eCryptfs inodes after a POSIX ACL was
set on the lower filesystem's inode.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=hwGP
-----END PGP SIGNATURE-----
Merge tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Fixes maximum filename length and filesystem type reporting in statfs() calls
and also fixes stale inode mode bits on eCryptfs inodes after a POSIX ACL was
set on the lower filesystem's inode.
* tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
ecryptfs: remove the second argument of k[un]map_atomic()
eCryptfs: Copy up lower inode attrs after setting lower xattr
eCryptfs: Improve statfs reporting
Here are a few more fixes for powerpc. Some are regressions, the rest
is simple/obvious/nasty enough that I deemed it good to go now.
Here's also step one of deprecating legacy iSeries support: we are
removing it from the main defconfig.
Nobody seems to be using it anymore and the code is nasty to maintain,
(involves horrible hacks in various low level areas of the kernel) so we
plan to actually rip it out at some point. For now let's just avoid
building it by default. Stephen will proceed to do the actual removal
later (probably 3.4 or 3.5).
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
powerpc/adb: Use set_current_state()
powerpc: Disable interrupts early in Program Check
powerpc: Remove legacy iSeries from ppc64_defconfig
powerpc/fsl/pci: Fix PCIe fixup regression
powerpc: Fix kernel log of oops/panic instruction dump
One regression fix for SR-IOV on PPC and a couple of misc fixes from
Yinghai.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci:
PCI: Fix pci cardbus removal
PCI: set pci sriov page size before reading SRIOV BAR
PCI: workaround hard-wired bus number V2
3 radeon fixes, I have some exynos fixes to push later but I'll queue
them separately once I've looked them over a bit.
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon/kms: fix MSI re-arm on rv370+
drm/radeon/kms/atom: bios scratch reg handling updates
drm/radeon/kms: drop lock in return path of radeon_fence_count_emitted.
After all the FPU state cleanups and finally finding the problem that
caused all our FPU save/restore problems, this re-introduces the
preloading of FPU state that was removed in commit b3b0870ef3 ("i387:
do not preload FPU state at task switch time").
However, instead of simply reverting the removal, this reimplements
preloading with several fixes, most notably
- properly abstracted as a true FPU state switch, rather than as
open-coded save and restore with various hacks.
In particular, implementing it as a proper FPU state switch allows us
to optimize the CR0.TS flag accesses: there is no reason to set the
TS bit only to then almost immediately clear it again. CR0 accesses
are quite slow and expensive, don't flip the bit back and forth for
no good reason.
- Make sure that the same model works for both x86-32 and x86-64, so
that there are no gratuitous differences between the two due to the
way they save and restore segment state differently due to
architectural differences that really don't matter to the FPU state.
- Avoid exposing the "preload" state to the context switch routines,
and in particular allow the concept of lazy state restore: if nothing
else has used the FPU in the meantime, and the process is still on
the same CPU, we can avoid restoring state from memory entirely, just
re-expose the state that is still in the FPU unit.
That optimized lazy restore isn't actually implemented here, but the
infrastructure is set up for it. Of course, older CPU's that use
'fnsave' to save the state cannot take advantage of this, since the
state saving also trashes the state.
In other words, there is now an actual _design_ to the FPU state saving,
rather than just random historical baggage. Hopefully it's easier to
follow as a result.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the bit that indicates whether a thread has ownership of the
FPU from the TS_USEDFPU bit in thread_info->status to a word of its own
(called 'has_fpu') in task_struct->thread.has_fpu.
This fixes two independent bugs at the same time:
- changing 'thread_info->status' from the scheduler causes nasty
problems for the other users of that variable, since it is defined to
be thread-synchronous (that's what the "TS_" part of the naming was
supposed to indicate).
So perfectly valid code could (and did) do
ti->status |= TS_RESTORE_SIGMASK;
and the compiler was free to do that as separate load, or and store
instructions. Which can cause problems with preemption, since a task
switch could happen in between, and change the TS_USEDFPU bit. The
change to TS_USEDFPU would be overwritten by the final store.
In practice, this seldom happened, though, because the 'status' field
was seldom used more than once, so gcc would generally tend to
generate code that used a read-modify-write instruction and thus
happened to avoid this problem - RMW instructions are naturally low
fat and preemption-safe.
- On x86-32, the current_thread_info() pointer would, during interrupts
and softirqs, point to a *copy* of the real thread_info, because
x86-32 uses %esp to calculate the thread_info address, and thus the
separate irq (and softirq) stacks would cause these kinds of odd
thread_info copy aliases.
This is normally not a problem, since interrupts aren't supposed to
look at thread information anyway (what thread is running at
interrupt time really isn't very well-defined), but it confused the
heck out of irq_fpu_usable() and the code that tried to squirrel
away the FPU state.
(It also caused untold confusion for us poor kernel developers).
It also turns out that using 'task_struct' is actually much more natural
for most of the call sites that care about the FPU state, since they
tend to work with the task struct for other reasons anyway (ie
scheduling). And the FPU data that we are going to save/restore is
found there too.
Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to
the %esp issue.
Cc: Arjan van de Ven <arjan@linux.intel.com>
Reported-and-tested-by: Raphael Prevost <raphael@buro.asia>
Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing the returned values on error messages is useful information.
While at it, use pr_err/pr_warn whenever possible.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
While it matches the current code only bringing the device out of reset
isn't actually doing what the function says so make sure we set the GPIO
high before we pull it low.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
