Commit graph

876 commits

Author SHA1 Message Date
Uwe Kleine-König
a2551d0a29 pwm: stm32-lp: Don't modify HW state in .remove() callback
[ Upstream commit d44084c934 ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:01 +02:00
Uwe Kleine-König
a6a2b36a8c pwm: rockchip: Don't modify HW state in .remove() callback
[ Upstream commit 9d768cd7fd ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:01 +02:00
Uwe Kleine-König
0a2ea5c0e5 pwm: img: Don't modify HW state in .remove() callback
[ Upstream commit c68eb29c8e ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:01 +02:00
Uwe Kleine-König
777344da34 pwm: mxs: Don't modify HW state in .probe() after the PWM chip was registered
commit 020162d6f4 upstream.

This fixes a race condition: After pwmchip_add() is called there might
already be a consumer and then modifying the hardware behind the
consumer's back is bad. So reset before calling pwmchip_add().

Note that reseting the hardware isn't the right thing to do if the PWM
is already running as it might e.g. disable (or even enable) a backlight
that is supposed to be on (or off).

Fixes: 4dce82c1e8 ("pwm: add pwm-mxs support")
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-26 14:08:58 +02:00
Uwe Kleine-König
322b70b522 pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered
commit 3d2813fb17 upstream.

This fixes a race condition: After pwmchip_add() is called there might
already be a consumer and then modifying the hardware behind the
consumer's back is bad. So set the default before.

(Side-note: I don't know what this register setting actually does, if
this modifies the polarity there is an inconsistency because the
inversed polarity isn't considered if the PWM is already running during
.probe().)

Fixes: acfd92fdfb ("pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value")
Cc: Sylvain Lemieux <slemieux@tycoint.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-26 14:08:58 +02:00
Uwe Kleine-König
d92337bf54 pwm: sprd: Ensure configuring period and duty_cycle isn't wrongly skipped
[ Upstream commit 65e2e6c1c2 ]

As the last call to sprd_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 8aae4b02e8 ("pwm: sprd: Add Spreadtrum PWM support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:34 +02:00
Uwe Kleine-König
527bb29eb1 pwm: imx1: Don't disable clocks at device remove time
[ Upstream commit 1bc6ea31cb ]

The .remove() callback disables clocks that were not enabled in
.probe(). So just probing and then unbinding the driver results in a clk
enable imbalance.

So just drop the call to disable the clocks. (Which BTW was also in the
wrong order because the call makes the PWM unfunctional and so should
have come only after pwmchip_remove()).

Fixes: 9f4c8f9607 ("pwm: imx: Add ipg clock operation")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:05:52 +02:00
Uwe Kleine-König
9dcc9ad343 pwm: tegra: Don't modify HW state in .remove callback
[ Upstream commit 86f7fa71cd ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:05:49 +02:00
Zou Wei
3d82361abd pwm: img: Fix PM reference leak in img_pwm_enable()
[ Upstream commit fde25294df ]

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:05:49 +02:00
Uwe Kleine-König
e133435232 pwm: spear: Don't modify HW state in .remove callback
[ Upstream commit b601a18f12 ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:05:46 +02:00
Uwe Kleine-König
b22e8f427c pwm: atmel: Fix duty cycle calculation in .get_state()
[ Upstream commit 453e8b3d8e ]

The CDTY register contains the number of inactive cycles. .apply() does
this correctly, however .get_state() got this wrong.

Fixes: 651b510a74 ("pwm: atmel: Implement .get_state()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:04 +02:00
Uwe Kleine-König
e47685ec4c pwm: iqs620a: Fix overflow and optimize calculations
[ Upstream commit 72d6b2459d ]

If state->duty_cycle is 0x100000000000000, the previous calculation of
duty_scale overflows and yields a duty cycle ratio of 0% instead of
100%. Fix this by clamping the requested duty cycle to the maximal
possible duty cycle first. This way it is possible to use a native
integer division instead of a (depending on the architecture) more
expensive 64bit division.

With this change in place duty_scale cannot be bigger than 256 which
allows to simplify the calculation of duty_val.

Fixes: 6f0841a819 ("pwm: Add support for Azoteq IQS620A PWM generator")
Tested-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:17 +01:00
Simon South
58516ac4aa pwm: rockchip: Eliminate potential race condition when probing
[ Upstream commit d21ba5d621 ]

Commit 48cf973cae ("pwm: rockchip: Avoid glitches on already running
PWMs") introduced a potential race condition in rockchip_pwm_probe(): A
consumer could enable an inactive PWM, or disable a running one, between
rockchip_pwm_probe() registering the device via pwmchip_add() and checking
whether it is enabled (to determine whether it was started by a
bootloader). This could result in a device's PWM clock being either enabled
once more than necessary, potentially causing it to continue running when
no longer needed, or disabled once more than necessary, producing a warning
from the kernel.

Eliminate these possibilities by modifying rockchip_pwm_probe() so it
checks whether a device is enabled before registering it rather than after.

Fixes: 48cf973cae ("pwm: rockchip: Avoid glitches on already running PWMs")
Reported-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:11 +01:00
Simon South
6f503e4e37 pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
[ Upstream commit d5d8d67586 ]

If rockchip_pwm_probe() fails to register a PWM device it calls
clk_unprepare() for the device's PWM clock, without having first disabled
the clock and before jumping to an error handler that also unprepares
it. This is likely to produce warnings from the kernel about the clock
being unprepared when it is still enabled, and then being unprepared when
it has already been unprepared.

Prevent these warnings by removing this unnecessary call to
clk_unprepare().

Fixes: 48cf973cae ("pwm: rockchip: Avoid glitches on already running PWMs")
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:11 +01:00
Simon South
39ab0927e7 pwm: rockchip: Enable APB clock during register access while probing
[ Upstream commit d9b657a5cd ]

Commit 457f74abbe ("pwm: rockchip: Keep enabled PWMs running while
probing") modified rockchip_pwm_probe() to access a PWM device's registers
directly to check whether or not the device is enabled, but did not also
change the function so it first enables the device's APB clock to be
certain the device can respond. This risks hanging the kernel on systems
with PWM devices that use more than a single clock.

Avoid this by enabling the device's APB clock before accessing its
registers (and disabling the clock when register access is complete).

Fixes: 457f74abbe ("pwm: rockchip: Keep enabled PWMs running while probing")
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Suggested-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:11 +01:00
Thierry Reding
4b14874409 pwm: sun4i: Remove erroneous else branch
[ Upstream commit 6eefb79d6f ]

Commit d3817a6470 ("pwm: sun4i: Remove redundant needs_delay") changed
the logic of an else branch so that the PWM_EN and PWM_CLK_GATING bits
are now cleared if the PWM is to be disabled, whereas previously the
condition was always false, and hence the branch never got executed.

This code is reported causing backlight issues on boards based on the
Allwinner A20 SoC. Fix this by removing the else branch, which restores
the behaviour prior to the offending commit.

Note that the PWM_EN and PWM_CLK_GATING bits still get cleared later in
sun4i_pwm_apply() if the PWM is to be disabled.

Fixes: d3817a6470 ("pwm: sun4i: Remove redundant needs_delay")
Reported-by: Taras Galchenko <tpgalchenko@gmail.com>
Suggested-by: Taras Galchenko <tpgalchenko@gmail.com>
Tested-by: Taras Galchenko <tpgalchenko@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:59 +01:00
Uwe Kleine-König
7c4544a216 pwm: imx27: Fix overflow for bigger periods
[ Upstream commit 1ce65396e6 ]

The second parameter of do_div is an u32 and NSEC_PER_SEC * prescale
overflows this for bigger periods. Assuming the usual pwm input clk rate
of 66 MHz this happens starting at requested period > 606060 ns.

Splitting the division into two operations doesn't loose any precision.
It doesn't need to be feared that c / NSEC_PER_SEC doesn't fit into the
unsigned long variable "duty_cycles" because in this case the assignment
above to period_cycles would already have been overflowing as
period >= duty_cycle and then the calculation is moot anyhow.

Fixes: aef1a3799b ("pwm: imx27: Fix rounding behavior")
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Tested-by: Johannes Pointner <johannes.pointner@br-automation.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:59 +01:00
Lokesh Vutla
2cacf60c92 pwm: lp3943: Dynamically allocate PWM chip base
[ Upstream commit 1f0f1e80fd ]

When there are other PWM controllers enabled along with pwm-lp3943,
pwm-lp3942 is failing to probe with -EEXIST error. This is because
other PWM controllers are probed first and assigned PWM base 0 and
pwm-lp3943 is requesting for 0 again.

In order to avoid this, assign the chip base with -1, so that it is
dynamically allocated.

Fixes: af66b3c093 ("pwm: Add LP3943 PWM driver")
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Uwe Kleine-König <u.kleine-könig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:59 +01:00
Uwe Kleine-König
00fb97e2d7 pwm: zx: Add missing cleanup in error path
[ Upstream commit 269effd03f ]

zx_pwm_probe() called clk_prepare_enable() before; this must be undone
in the error path.

Fixes: 4836193c43 ("pwm: Add ZTE ZX PWM device driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:58 +01:00
Uwe Kleine-König
062c9cdf60 pwm: sl28cpld: fix getting driver data in pwm callbacks
Currently .get_state() and .apply() use dev_get_drvdata() on the struct
device related to the pwm chip.  This only works after .probe() called
platform_set_drvdata() which in this driver happens only after
pwmchip_add() and so comes possibly too late.

Instead of setting the driver data earlier use the traditional
container_of approach as this way the driver data is conceptually and
computational nearer.

Fixes: 9db33d221e ("pwm: Add support for sl28cpld PWM controller")
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-03 09:57:37 -08:00
Linus Torvalds
e731f3146f ARM: SoC platform updates
SoC changes, a substantial part of this is cleanup of some of the older
 platforms that used to have a bunch of board files. In particular:
 
  - Removal of non-DT i.MX platforms that haven't seen activity in years,
    it's time to remove them.
  - A bunch of cleanup and removal of platform data for TI/OMAP platforms,
    moving over to genpd for power/reset control (yay!)
  - Major cleanup of Samsung S3C24xx and S3C64xx platforms, moving them
    closer to multiplatform support (not quite there yet, but getting
    close).
 
 THere are a few other changes too, smaller fixlets, etc. For new
 platform support, the primary ones re:
 
  - New SoC: Hisilicon SD5203, ARM926EJ-S platform.
  - Cpufreq support for i.MX7ULP
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Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC platform updates from Olof Johansson:
 "SoC changes, a substantial part of this is cleanup of some of the
  older platforms that used to have a bunch of board files.

  In particular:

   - Remove non-DT i.MX platforms that haven't seen activity in years,
     it's time to remove them.

   - A bunch of cleanup and removal of platform data for TI/OMAP
     platforms, moving over to genpd for power/reset control (yay!)

   - Major cleanup of Samsung S3C24xx and S3C64xx platforms, moving them
     closer to multiplatform support (not quite there yet, but getting
     close).

  There are a few other changes too, smaller fixlets, etc. For new
  platform support, the primary ones are:

   - New SoC: Hisilicon SD5203, ARM926EJ-S platform.

   - Cpufreq support for i.MX7ULP"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (121 commits)
  ARM: mstar: Select MStar intc
  ARM: stm32: Replace HTTP links with HTTPS ones
  ARM: debug: add UART early console support for SD5203
  ARM: hisi: add support for SD5203 SoC
  ARM: omap3: enable off mode automatically
  clk: imx: imx35: Remove mx35_clocks_init()
  clk: imx: imx31: Remove mx31_clocks_init()
  clk: imx: imx27: Remove mx27_clocks_init()
  ARM: imx: Remove unused definitions
  ARM: imx35: Retrieve the IIM base address from devicetree
  ARM: imx3: Retrieve the AVIC base address from devicetree
  ARM: imx3: Retrieve the CCM base address from devicetree
  ARM: imx31: Retrieve the IIM base address from devicetree
  ARM: imx27: Retrieve the CCM base address from devicetree
  ARM: imx27: Retrieve the SYSCTRL base address from devicetree
  ARM: s3c64xx: bring back notes from removed debug-macro.S
  ARM: s3c24xx: fix Wunused-variable warning on !MMU
  ARM: samsung: fix PM debug build with DEBUG_LL but !MMU
  MAINTAINERS: mark linux-samsung-soc list non-moderated
  ARM: imx: Remove remnant board file support pieces
  ...
2020-10-24 10:33:08 -07:00
Linus Torvalds
090a7d046f chrome platform changes for 5.10
cros-ec:
 * Error code cleanup across cros-ec by Guenter.
 * Remove cros_ec_cmd_xfer in favor of cros_ec_cmd_xfer_status.
 
 cros_ec_typec:
 * Landed initial USB4 support in typec connector class driver for cros_ec.
 * Role switch bugfix on disconnect, and reordering configuration steps.
 
 cros_ec_lightbar:
 * Fix buffer outsize and result for get_lightbar_version.
 
 misc:
 * Remove config MFD_CROS_EC, now that transition from MFD is complete.
 * Enable KEY_LEFTMETA in new location on arm based cros-ec-keyboard keymap.
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Merge tag 'tag-chrome-platform-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux

Pull chrome platform updates from Benson Leung:
 "cros-ec:
   - Error code cleanup across cros-ec by Guenter
   - Remove cros_ec_cmd_xfer in favor of cros_ec_cmd_xfer_status

  cros_ec_typec:
   - Landed initial USB4 support in typec connector class driver for
     cros_ec
   - Role switch bugfix on disconnect, and reordering configuration
     steps

  cros_ec_lightbar:
   - Fix buffer outsize and result for get_lightbar_version

  misc:
   - Remove config MFD_CROS_EC, now that transition from MFD is complete
   - Enable KEY_LEFTMETA in new location on arm based cros-ec-keyboard
     keymap"

* tag 'tag-chrome-platform-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux:
  ARM: dts: cros-ec-keyboard: Add alternate keymap for KEY_LEFTMETA
  platform/chrome: Use kobj_to_dev() instead of container_of()
  platform/chrome: cros_ec_proto: Drop cros_ec_cmd_xfer()
  platform/chrome: cros_ec_proto: Update cros_ec_cmd_xfer() call-sites
  platform/chrome: Kconfig: Remove the transitional MFD_CROS_EC config
  platform/chrome: cros_ec_lightbar: Reduce ligthbar get version command
  platform/chrome: cros_ec_trace: Add fields to command traces
  platform/chrome: cros_ec_typec: Re-order connector configuration steps
  platform/chrome: cros_ec_typec: Avoid setting usb role twice during disconnect
  platform/chrome: cros_ec_typec: Send enum values to usb_role_switch_set_role()
  platform/chrome: cros_ec_typec: USB4 support
  pwm: cros-ec: Simplify EC error handling
  platform/chrome: cros_ec_proto: Convert EC error codes to Linux error codes
  platform/input: cros_ec: Replace -ENOTSUPP with -ENOPROTOOPT
  pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_status
  platform/chrome: cros_ec_sysfs: Report range of error codes from EC
  cros_ec_lightbar: Accept more error codes from cros_ec_cmd_xfer_status
  iio: cros_ec: Accept -EOPNOTSUPP as 'not supported' error code
2020-10-23 10:54:13 -07:00
Linus Torvalds
ceae608a54 pwm: Changes for v5.10-rc1
This release cycle's updates are mostly cleanup and some minor fixes.
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Merge tag 'pwm/for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This release cycle's updates are mostly cleanup and some minor fixes"

* tag 'pwm/for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  dt-bindings: pwm: renesas,pwm-rcar: Add r8a7742 support
  dt-bindings: pwm: renesas,tpu-pwm: Document r8a7742 support
  pwm: Allow store 64-bit duty cycle from sysfs interface
  pwm: img: Fix null pointer access in probe
  pwm: pca9685: Disable unused alternative addresses
  pwm: pca9685: Use BIT() macro instead of shift
  pwm: pca9685: Make comments more consistent
  pwm: sun4i: Simplify with dev_err_probe()
  pwm: sprd: Simplify with dev_err_probe()
  pwm: sifive: Simplify with dev_err_probe()
  pwm: rockchip: Simplify with dev_err_probe()
  pwm: jz4740: Simplify with dev_err_probe()
  pwm: bcm2835: Simplify with dev_err_probe()
  pwm: Convert to use DEFINE_SEQ_ATTRIBUTE macro
  pwm: rockchip: Keep enabled PWMs running while probing
  dt-bindings: pwm: renesas,pwm-rcar: Add r8a774e1 support
2020-10-22 12:51:32 -07:00
Linus Torvalds
93b694d096 drm next for 5.10-rc1
New driver:
 Cadence MHDP8546 DisplayPort bridge driver
 
 core:
 - cross-driver scatterlist cleanups
 - devm_drm conversions
 - remove drm_dev_init
 - devm_drm_dev_alloc conversion
 
 ttm:
 - lots of refactoring and cleanups
 
 bridges:
 - chained bridge support in more drivers
 
 panel:
 - misc new panels
 
 scheduler:
 - cleanup priority levels
 
 displayport:
 - refactor i915 code into helpers for nouveau
 
 i915:
 - split into display and GT trees
 - WW locking refactoring in GEM
 - execbuf2 extension mechanism
 - syncobj timeline support
 - GEN 12 HOBL display powersaving
 - Rocket Lake display additions
 - Disable FBC on Tigerlake
 - Tigerlake Type-C + DP improvements
 - Hotplug interrupt refactoring
 
 amdgpu:
 - Sienna Cichlid updates
 - Navy Flounder updates
 - DCE6 (SI) support for DC
 - Plane rotation enabled
 - TMZ state info ioctl
 - PCIe DPC recovery support
 - DC interrupt handling refactor
 - OLED panel fixes
 
 amdkfd:
 - add SMI events for thermal throttling
 - SMI interface events ioctl update
 - process eviction counters
 
 radeon:
 - move to dma_ for allocations
 - expose sclk via sysfs
 
 msm:
 - DSI support for sm8150/sm8250
 - per-process GPU pagetable support
 - Displayport support
 
 mediatek:
 - move HDMI phy driver to PHY
 - convert mtk-dpi to bridge API
 - disable mt2701 tmds
 
 tegra:
 - bridge support
 
 exynos:
 - misc cleanups
 
 vc4:
 - dual display cleanups
 
 ast:
 - cleanups
 
 gma500:
 - conversion to GPIOd API
 
 hisilicon:
 - misc reworks
 
 ingenic:
 - clock handling and format improvements
 
 mcde:
 - DSI support
 
 mgag200:
 - desktop g200 support
 
 mxsfb:
 - i.MX7 + i.MX8M
 - alpha plane support
 
 panfrost:
 - devfreq support
 - amlogic SoC support
 
 ps8640:
 - EDID from eDP retrieval
 
 tidss:
 - AM65xx YUV workaround
 
 virtio:
 - virtio-gpu exported resources
 
 rcar-du:
 - R8A7742, R8A774E1 and R8A77961 support
 - YUV planar format fixes
 - non-visible plane handling
 - VSP device reference count fix
 - Kconfig fix to avoid displaying disabled options in .config
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Merge tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm

Pull drm updates from Dave Airlie:
 "Not a major amount of change, the i915 trees got split into display
  and gt trees to better facilitate higher level review, and there's a
  major refactoring of i915 GEM locking to use more core kernel concepts
  (like ww-mutexes). msm gets per-process pagetables, older AMD SI cards
  get DC support, nouveau got a bump in displayport support with common
  code extraction from i915.

  Outside of drm this contains a couple of patches for hexint
  moduleparams which you've acked, and a virtio common code tree that
  you should also get via it's regular path.

  New driver:
   - Cadence MHDP8546 DisplayPort bridge driver

  core:
   - cross-driver scatterlist cleanups
   - devm_drm conversions
   - remove drm_dev_init
   - devm_drm_dev_alloc conversion

  ttm:
   - lots of refactoring and cleanups

  bridges:
   - chained bridge support in more drivers

  panel:
   - misc new panels

  scheduler:
   - cleanup priority levels

  displayport:
   - refactor i915 code into helpers for nouveau

  i915:
   - split into display and GT trees
   - WW locking refactoring in GEM
   - execbuf2 extension mechanism
   - syncobj timeline support
   - GEN 12 HOBL display powersaving
   - Rocket Lake display additions
   - Disable FBC on Tigerlake
   - Tigerlake Type-C + DP improvements
   - Hotplug interrupt refactoring

  amdgpu:
   - Sienna Cichlid updates
   - Navy Flounder updates
   - DCE6 (SI) support for DC
   - Plane rotation enabled
   - TMZ state info ioctl
   - PCIe DPC recovery support
   - DC interrupt handling refactor
   - OLED panel fixes

  amdkfd:
   - add SMI events for thermal throttling
   - SMI interface events ioctl update
   - process eviction counters

  radeon:
   - move to dma_ for allocations
   - expose sclk via sysfs

  msm:
   - DSI support for sm8150/sm8250
   - per-process GPU pagetable support
   - Displayport support

  mediatek:
   - move HDMI phy driver to PHY
   - convert mtk-dpi to bridge API
   - disable mt2701 tmds

  tegra:
   - bridge support

  exynos:
   - misc cleanups

  vc4:
   - dual display cleanups

  ast:
   - cleanups

  gma500:
   - conversion to GPIOd API

  hisilicon:
   - misc reworks

  ingenic:
   - clock handling and format improvements

  mcde:
   - DSI support

  mgag200:
   - desktop g200 support

  mxsfb:
   - i.MX7 + i.MX8M
   - alpha plane support

  panfrost:
   - devfreq support
   - amlogic SoC support

  ps8640:
   - EDID from eDP retrieval

  tidss:
   - AM65xx YUV workaround

  virtio:
   - virtio-gpu exported resources

  rcar-du:
   - R8A7742, R8A774E1 and R8A77961 support
   - YUV planar format fixes
   - non-visible plane handling
   - VSP device reference count fix
   - Kconfig fix to avoid displaying disabled options in .config"

* tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm: (1494 commits)
  drm/ingenic: Fix bad revert
  drm/amdgpu: Fix invalid number of character '{' in amdgpu_acpi_init
  drm/amdgpu: Remove warning for virtual_display
  drm/amdgpu: kfd_initialized can be static
  drm/amd/pm: setup APU dpm clock table in SMU HW initialization
  drm/amdgpu: prevent spurious warning
  drm/amdgpu/swsmu: fix ARC build errors
  drm/amd/display: Fix OPTC_DATA_FORMAT programming
  drm/amd/display: Don't allow pstate if no support in blank
  drm/panfrost: increase readl_relaxed_poll_timeout values
  MAINTAINERS: Update entry for st7703 driver after the rename
  Revert "gpu/drm: ingenic: Add option to mmap GEM buffers cached"
  drm/amd/display: HDMI remote sink need mode validation for Linux
  drm/amd/display: Change to correct unit on audio rate
  drm/amd/display: Avoid set zero in the requested clk
  drm/amdgpu: align frag_end to covered address space
  drm/amdgpu: fix NULL pointer dereference for Renoir
  drm/vmwgfx: fix regression in thp code due to ttm init refactor.
  drm/amdgpu/swsmu: add interrupt work handler for smu11 parts
  drm/amdgpu/swsmu: add interrupt work function
  ...
2020-10-15 10:46:16 -07:00
Jarkko Nikula
1f2bd2271a pwm: Allow store 64-bit duty cycle from sysfs interface
PWM core was converted to u64 by the commit a9d887dc1c ("pwm: Convert
period and duty cycle to u64") but did not change the duty_cycle_store()
so it will error out if trying to pass a numeric string bigger than
2^32-1.

Fix this by using u64 and kstrtou64() in duty_cycle_store().

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:14 +02:00
Hauke Mehrtens
b39c0615d0 pwm: img: Fix null pointer access in probe
dev_get_drvdata() is called in img_pwm_runtime_resume() before the
driver data is set.
When pm_runtime_enabled() returns false in img_pwm_probe() it calls
img_pwm_runtime_resume() which results in a null pointer access.

This patch fixes the problem by setting the driver data earlier in the
img_pwm_probe() function.

This crash was seen when booting the Imagination Technologies Creator
Ci40 (Marduk) with kernel 5.4 in OpenWrt.

Fixes: e690ae5262 ("pwm: img: Add runtime PM")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:13 +02:00
David Jander
bce5436694 pwm: pca9685: Disable unused alternative addresses
The PCA9685 supports listening to 1 or more alternative I2C chip addresses
for some special features that this driver does not support.
By default the LED ALLCALL address is active (default 0x70), which causes
this chip to respond to address 0x70 in addition to its main address
(0x41). This is not desireable if there is another device on the same bus
that uses this address (like a TMP103 for example).
Since this feature is not supported by this driver, it is best to disable
these addresses in the chip to avoid unsuspected bus collisions.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:13 +02:00
David Jander
e1057a8df1 pwm: pca9685: Use BIT() macro instead of shift
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:13 +02:00
David Jander
316b676bd4 pwm: pca9685: Make comments more consistent
Make all explanatory comments start with an uppercase char.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:13 +02:00
Krzysztof Kozlowski
5327f34bf8 pwm: sun4i: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:12 +02:00
Krzysztof Kozlowski
793bb636f5 pwm: sprd: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:11 +02:00
Krzysztof Kozlowski
5530fcaf9c pwm: sifive: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:11 +02:00
Krzysztof Kozlowski
836719f894 pwm: rockchip: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:10 +02:00
Krzysztof Kozlowski
c0bfe9606e pwm: jz4740: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:10 +02:00
Krzysztof Kozlowski
85a5745f17 pwm: bcm2835: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:10 +02:00
Liu Shixin
f339e79bae pwm: Convert to use DEFINE_SEQ_ATTRIBUTE macro
Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:09 +02:00
Simon South
457f74abbe pwm: rockchip: Keep enabled PWMs running while probing
Following commit cfc4c189bc ("pwm: Read initial hardware state at
request time") the Rockchip PWM driver can no longer assume a device's
pwm_state structure has been populated after a call to pwmchip_add().
Consequently, the test in rockchip_pwm_probe() intended to prevent the
driver from stopping PWM devices already enabled by the bootloader no
longer functions reliably and this can lead to the kernel hanging
during startup, particularly on devices like the Pinebook Pro that use
a PWM-controlled backlight for their display.

Avoid this by querying the device directly at probe time to determine
whether or not it is enabled.

Fixes: cfc4c189bc ("pwm: Read initial hardware state at request time")
Signed-off-by: Simon South <simon@simonsouth.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:08 +02:00
Michael Walle
9db33d221e pwm: Add support for sl28cpld PWM controller
Add support for the PWM controller of the sl28cpld board management
controller. This is part of a multi-function device driver.

The controller has one PWM channel and can just generate four distinct
frequencies.

Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-09-17 15:59:34 +01:00
Rodrigo Vivi
0ea8a56de2 Merge drm/drm-next into drm-intel-next-queued
Sync drm-intel-gt-next here so we can have an unified fixes flow.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-09-11 20:00:20 -04:00
Hans de Goede
c86b155da7 pwm: crc: Implement get_state() method
Implement the pwm_ops.get_state() method to complete the support for the
new atomic PWM API.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-14-hdegoede@redhat.com
2020-09-06 15:38:05 +02:00
Hans de Goede
9fccec8219 pwm: crc: Implement apply() method to support the new atomic PWM API
Replace the enable, disable and config pwm_ops with an apply op,
to support the new atomic PWM API.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-13-hdegoede@redhat.com
2020-09-06 15:38:04 +02:00
Hans de Goede
6fdefe6089 pwm: crc: Enable/disable PWM output on enable/disable
The pwm-crc code is using 2 different enable bits:
1. bit 7 of the PWM0_CLK_DIV (PWM_OUTPUT_ENABLE)
2. bit 0 of the BACKLIGHT_EN register

So far we've kept the PWM_OUTPUT_ENABLE bit set when disabling the PWM,
this commit makes crc_pwm_disable() clear it on disable and makes
crc_pwm_enable() set it again on re-enable.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-12-hdegoede@redhat.com
2020-09-06 15:38:04 +02:00
Hans de Goede
6158231a84 pwm: crc: Fix period changes not having any effect
The pwm-crc code is using 2 different enable bits:
1. bit 7 of the PWM0_CLK_DIV (PWM_OUTPUT_ENABLE)
2. bit 0 of the BACKLIGHT_EN register

The BACKLIGHT_EN register at address 0x51 really controls a separate
output-only GPIO which is earmarked to be used as output connected to the
backlight-enable pin for LCD panels, this GPO is part of the PMIC's
"Display Panel Control Block." . This pin should probably be moved over
to a GPIO provider driver (and consumers modified accordingly), but that
is something for an(other) patch.

Enabling / disabling the actual PWM output is controlled by the
PWM_OUTPUT_ENABLE bit of the PWM0_CLK_DIV register.

As the comment in the old code already indicates we must disable the PWM
before we can change the clock divider. But the crc_pwm_disable() and
crc_pwm_enable() calls the old code make for this only change the
BACKLIGHT_EN register; and the value of that register does not matter for
changing the period / the divider. What does matter is that the
PWM_OUTPUT_ENABLE bit must be cleared before a new value can be written.

This commit modifies crc_pwm_config() to clear PWM_OUTPUT_ENABLE instead
when changing the period, so that period changes actually work.

Note this fix will cause a significant behavior change on some devices
using the CRC PWM output to drive their backlight. Before the PWM would
always run with the output frequency configured by the BIOS at boot, now
the period time specified by the i915 driver will actually be honored.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-11-hdegoede@redhat.com
2020-09-06 15:38:03 +02:00
Hans de Goede
a05af71f0d pwm: crc: Fix off-by-one error in the clock-divider calculations
The CRC PWM controller has a clock-divider which divides the clock with
a value between 1-128. But as can seen from the PWM_DIV_CLK_xxx
defines, this range maps to a register value of 0-127.

So after calculating the clock-divider we must subtract 1 to get the
register value, unless the requested frequency was so high that the
calculation has already resulted in a (rounded) divider value of 0.

Note that before this fix, setting a period of PWM_MAX_PERIOD_NS which
corresponds to the max. divider value of 128 could have resulted in a
bug where the code would use 128 as divider-register value which would
have resulted in an actual divider value of 0 (and the enable bit being
set). A rounding error stopped this bug from actually happen. This
same rounding error means that after the subtraction of 1 it is impossible
to set the divider to 128. Also bump PWM_MAX_PERIOD_NS by 1 ns to allow
setting a divider of 128 (register-value 127).

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-10-hdegoede@redhat.com
2020-09-06 15:38:02 +02:00
Hans de Goede
79e0899275 pwm: crc: Fix period / duty_cycle times being off by a factor of 256
While looking into adding atomic-pwm support to the pwm-crc driver I
noticed something odd, there is a PWM_BASE_CLK define of 6 MHz and
there is a clock-divider which divides this with a value between 1-128,
and there are 256 duty-cycle steps.

The pwm-crc code before this commit assumed that a clock-divider
setting of 1 means that the PWM output is running at 6 MHZ, if that
is true, where do these 256 duty-cycle steps come from?

This would require an internal frequency of 256 * 6 MHz = 1.5 GHz, that
seems unlikely for a PMIC which is using a silicon process optimized for
power-switching transistors. It is way more likely that there is an 8
bit counter for the duty cycle which acts as an extra fixed divider
wrt the PWM output frequency.

The main user of the pwm-crc driver is the i915 GPU driver which uses it
for backlight control. Lets compare the PWM register values set by the
video-BIOS (the GOP), assuming the extra fixed divider is present versus
the PWM frequency specified in the Video-BIOS-Tables:

Device:		PWM Hz set by BIOS	PWM Hz specified in VBT
Asus T100TA 	200			200
Asus T100HA 	200			200
Lenovo Miix 2 8	23437			20000
Toshiba WT8-A	23437			20000

So as we can see if we assume the extra division by 256 then the register
values set by the GOP are an exact match for the VBT values, where as
otherwise the values would be of by a factor of 256.

This commit fixes the period / duty_cycle calculations to take the
extra division by 256 into account.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-9-hdegoede@redhat.com
2020-09-06 15:38:02 +02:00
Hans de Goede
547d9e9261 pwm: lpss: Remove suspend/resume handlers
PWM controller drivers should not restore the PWM state on resume. The
convention is that PWM consumers do this by calling pwm_apply_state(),
so that it can be done at the exact moment when the consumer needs
the state to be stored, avoiding e.g. backlight flickering.

The only in kernel consumers of the pwm-lpss code, the i915 driver
and the pwm-class sysfs interface code both correctly restore the
state on resume, so there is no need to do this in the pwm-lpss code.

More-over the removed resume handler is buggy, since it blindly
restores the ctrl-register contents without setting the update
bit, which is necessary to get the controller to actually use/apply
the restored base-unit and on-time-div values.

Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-8-hdegoede@redhat.com
2020-09-06 15:38:01 +02:00
Hans de Goede
d6d54bacb1 pwm: lpss: Make pwm_lpss_apply() not rely on existing hardware state
Before this commit pwm_lpss_apply() was assuming 2 pre-conditions
were met by the existing hardware state:

1. That the base-unit and on-time-div read back from the
control register are those actually in use, so that it
can skip setting the update bit if the read-back value
matches the desired values.

2. That the controller is enabled when the cached
pwm_state.enabled says that the controller is enabled.

As the long history of fixes for subtle (often suspend/resume)
lpss-pwm issues shows, these assumptions are not necessary
always true.

1. Specifically is not true on some (*) Cherry Trail devices
with a nasty GFX0._PS3 method which: a. saves the ctrl reg value.
b. sets the base-unit to 0 and writes the update bit to apply/commit
c. restores the original ctrl value without setting the update bit,
so that the 0 base-unit value is still in use.

2. Assumption 2. currently is true, but only because of the code which
saves/restores the state on suspend/resume. By convention restoring the
PWM state should be done by the PWM consumer and the presence of this
code in the pmw-lpss driver is a bug. Therefor the save/restore code will
be dropped in the next patch in this series, after which this assumption
also is no longer true.

This commit changes the pwm_lpss_apply() to not make any assumptions about
the state the hardware is in. Instead it makes pwm_lpss_apply() always
fully program the PWM controller, making it much less fragile.

*) Seen on the Acer One 10 S1003, Lenovo Ideapad Miix 310 and 320 models
and various Medion models.

Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-7-hdegoede@redhat.com
2020-09-06 15:38:00 +02:00
Hans de Goede
092d83e3f5 pwm: lpss: Add pwm_lpss_prepare_enable() helper
In the not-enabled -> enabled path pwm_lpss_apply() needs to get a
runtime-pm reference; and then on any errors it needs to release it
again.

This leads to somewhat hard to read code. This commit introduces a new
pwm_lpss_prepare_enable() helper and moves all the steps necessary for
the not-enabled -> enabled transition there, so that we can error check
the entire transition in a single place and only have one pm_runtime_put()
on failure call site.

While working on this I noticed that the enabled -> enabled (update
settings) path was quite similar, so I've added an enable parameter to
the new pwm_lpss_prepare_enable() helper, which allows using it in that
path too.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-6-hdegoede@redhat.com
2020-09-06 15:38:00 +02:00
Hans de Goede
ef9f60daab pwm: lpss: Add range limit check for the base_unit register value
When the user requests a high enough period ns value, then the
calculations in pwm_lpss_prepare() might result in a base_unit value of 0.

But according to the data-sheet the way the PWM controller works is that
each input clock-cycle the base_unit gets added to a N bit counter and
that counter overflowing determines the PWM output frequency. Adding 0
to the counter is a no-op. The data-sheet even explicitly states that
writing 0 to the base_unit bits will result in the PWM outputting a
continuous 0 signal.

When the user requestes a low enough period ns value, then the
calculations in pwm_lpss_prepare() might result in a base_unit value
which is bigger then base_unit_range - 1. Currently the codes for this
deals with this by applying a mask:

	base_unit &= (base_unit_range - 1);

But this means that we let the value overflow the range, we throw away the
higher bits and store whatever value is left in the lower bits into the
register leading to a random output frequency, rather then clamping the
output frequency to the highest frequency which the hardware can do.

This commit fixes both issues by clamping the base_unit value to be
between 1 and (base_unit_range - 1).

Fixes: 684309e504 ("pwm: lpss: Avoid potential overflow of base_unit")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-5-hdegoede@redhat.com
2020-09-06 15:37:59 +02:00
Hans de Goede
181f4d2f44 pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare()
According to the data-sheet the way the PWM controller works is that
each input clock-cycle the base_unit gets added to a N bit counter and
that counter overflowing determines the PWM output frequency.

So assuming e.g. a 16 bit counter this means that if base_unit is set to 1,
after 65535 input clock-cycles the counter has been increased from 0 to
65535 and it will overflow on the next cycle, so it will overflow after
every 65536 clock cycles and thus the calculations done in
pwm_lpss_prepare() should use 65536 and not 65535.

This commit fixes this. Note this also aligns the calculations in
pwm_lpss_prepare() with those in pwm_lpss_get_state().

Note this effectively reverts commit 684309e504 ("pwm: lpss: Avoid
potential overflow of base_unit"). The next patch in this series really
fixes the potential overflow of the base_unit value.

Fixes: 684309e504 ("pwm: lpss: Avoid potential overflow of base_unit")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-4-hdegoede@redhat.com
2020-09-06 15:37:58 +02:00