442 Commits

Author SHA1 Message Date
Uwe Kleine-König
1999e2c432 pwm: lp3943: Fix duty calculation in case period was clamped
[ Upstream commit 5e3b07ca5cc78cd4a987e78446849e41288d87cb ]

The hardware only supports periods <= 1.6 ms and if a bigger period is
requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger
than 1.6 ms and then the duty cycle register is written with a value
bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly.

Fixes: af66b3c0934e ("pwm: Add LP3943 PWM 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>
2022-06-14 16:52:37 +02:00
Uwe Kleine-König
553cdc1a92 pwm: lpc18xx-sct: Initialize driver data and hardware before pwmchip_add()
[ Upstream commit 0401f24cd238ae200a23a13925f98de3d2c883b8 ]

When a driver calls pwmchip_add() it has to be prepared to immediately
get its callbacks called. So move allocation of driver data and hardware
initialization before the call to pwmchip_add().

This fixes a potential NULL pointer exception and a race condition on
register writes.

Fixes: 841e6f90bb78 ("pwm: NXP LPC18xx PWM/SCT 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>
2022-04-20 09:06:36 +02:00
Uwe Kleine-König
7fc2172ad4 pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered
commit 3d2813fb17e5fd0d73c1d1442ca0192bde4af10e 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: acfd92fdfb93 ("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 13:36:18 +02:00
Uwe Kleine-König
7ccf66b8cb pwm: tegra: Don't modify HW state in .remove callback
[ Upstream commit 86f7fa71cd830d18d7ebcaf719dffd5ddfe1acdd ]

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 16:21:14 +02:00
Uwe Kleine-König
1f459d80e4 pwm: spear: Don't modify HW state in .remove callback
[ Upstream commit b601a18f12383001e7a8da238de7ca1559ebc450 ]

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 16:21:13 +02:00
Simon South
2af5bd8b91 pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
[ Upstream commit d5d8d675865ccddfe4da26c85f22c55cec663bf2 ]

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: 48cf973cae33 ("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>
2021-03-03 17:44:39 +01:00
Rayagonda Kokatanur
d0883cb88a pwm: bcm-iproc: handle clk_get_rate() return
[ Upstream commit 6ced5ff0be8e94871ba846dfbddf69d21363f3d7 ]

Handle clk_get_rate() returning 0 to avoid possible division by zero.

Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller")
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.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>
2020-08-21 11:02:10 +02:00
Florian Fainelli
4c237ff333 pwm: bcm2835: Dynamically allocate base
[ Upstream commit 2c25b07e5ec119cab609e41407a1fb3fa61442f5 ]

The newer 2711 and 7211 chips have two PWM controllers and failure to
dynamically allocate the PWM base would prevent the second PWM
controller instance being probed for succeeding with an -EEXIST error
from alloc_pwms().

Fixes: e5a06dc5ac1f ("pwm: Add BCM2835 PWM driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:23:07 +02:00
Geert Uytterhoeven
ba37c3bafd pwm: renesas-tpu: Fix late Runtime PM enablement
[ Upstream commit d5a3c7a4536e1329a758e14340efd0e65252bd3d ]

Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should always be disabled after the removal of the
PWM chip, even if the latter failed.

Fixes: 99b82abb0a35b073 ("pwm: Add Renesas TPU PWM driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:23:07 +02:00
Geert Uytterhoeven
3c33445d2b pwm: rcar: Fix late Runtime PM enablement
[ Upstream commit 1451a3eed24b5fd6a604683f0b6995e0e7e16c79 ]

Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should be disabled after the removal of the PWM
chip.

Fixes: ed6c1476bf7f16d5 ("pwm: Add support for R-Car PWM Timer")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:23:04 +02:00
Uwe Kleine-König
d8c8434dad pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional
[ Upstream commit 43efdc8f0e6d7088ec61bd55a73bf853f002d043 ]

In the old code (e.g.) mutex_destroy() was called before
pwmchip_remove(). Between these two calls it is possible that a PWM
callback is used which tries to grab the mutex.

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
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>
2020-02-28 15:42:35 +01:00
Bichao Zheng
e5195f7863 pwm: meson: Don't disable PWM when setting duty repeatedly
[ Upstream commit a279345807e1e0ae79567a52cfdd9d30c9174a3c ]

There is an abnormally low about 20ms,when setting duty repeatedly.
Because setting the duty will disable PWM and then enable. Delete
this operation now.

Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Bichao Zheng <bichao.zheng@amlogic.com>
[ Dropped code instead of hiding it behind a comment ]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-29 10:24:24 +01:00
Hans de Goede
7f6e0f44e5 pwm: lpss: Release runtime-pm reference from the driver's remove callback
[ Upstream commit 42885551cedb45961879d2fc3dc3c4dc545cc23e ]

For each pwm output which gets enabled through pwm_lpss_apply(), we do a
pm_runtime_get_sync().

This commit adds pm_runtime_put() calls to pwm_lpss_remove() to balance
these when the driver gets removed with some of the outputs still enabled.

Fixes: f080be27d7d9 ("pwm: lpss: Add support for runtime PM")
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-29 10:24:02 +01:00
Uwe Kleine-König
564295c56b pwm: Clear chip_data in pwm_put()
commit e926b12c611c2095c7976e2ed31753ad6eb5ff1a upstream.

After a PWM is disposed by its user the per chip data becomes invalid.
Clear the data in common code instead of the device drivers to get
consistent behaviour. Before this patch only three of nine drivers
cleaned up here.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05 15:35:23 +01:00
Alexander Shiyan
3c1af2c0a3 pwm: clps711x: Fix period calculation
[ Upstream commit b0f17570b8203c22f139459c86cfbaa0311313ed ]

Commit e39c0df1be5a ("pwm: Introduce the pwm_args concept") has
changed the variable for the period for clps711x-pwm driver, so now
pwm_get/set_period() works with pwm->state.period variable instead
of pwm->args.period.
This patch changes the period variable in other places where it is used.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:34:54 +01:00
Uwe Kleine-König
339b3e9bb6 pwm: bcm-iproc: Prevent unloading the driver module while in use
[ Upstream commit 24906a41eecb73d51974ade0847c21e429beec60 ]

The owner member of struct pwm_ops must be set to THIS_MODULE to
increase the reference count of the module such that the module cannot
be removed while its code is in use.

Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:34:12 +01:00
Phong Hoang
d7650c74b6 pwm: Fix deadlock warning when removing PWM device
[ Upstream commit 347ab9480313737c0f1aaa08e8f2e1a791235535 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 #7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> #1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424c9ba9
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
[shimoda: revise the commit log and code]
Fixes: 76abbdde2d95 ("pwm: Add sysfs interface")
Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
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>
2019-06-22 08:17:17 +02:00
Christoph Vogtländer
2ed354026f pwm: tiehrpwm: Update shadow register for disabling PWMs
[ Upstream commit b00ef53053191d3025c15e8041699f8c9d132daf ]

It must be made sure that immediate mode is not already set, when
modifying shadow register value in ehrpwm_pwm_disable(). Otherwise
modifications to the action-qualifier continuous S/W force
register(AQSFRC) will be done in the active register.
This may happen when both channels are being disabled. In this case,
only the first channel state will be recorded as disabled in the shadow
register. Later, when enabling the first channel again, the second
channel would be enabled as well. Setting RLDCSF to zero, first, ensures
that the shadow register is updated as desired.

Fixes: 38dabd91ff0b ("pwm: tiehrpwm: Fix disabling of output of PWMs")
Signed-off-by: Christoph Vogtländer <c.vogtlaender@sigma-surface-science.com>
[vigneshr@ti.com: Improve commit message]
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22 08:17:17 +02:00
Martin Blumenstingl
d7541cb8df pwm: meson: Use the spin-lock only to protect register modifications
[ Upstream commit f173747fffdf037c791405ab4f1ec0eb392fc48e ]

Holding the spin-lock for all of the code in meson_pwm_apply() can
result in a "BUG: scheduling while atomic". This can happen because
clk_get_rate() (which is called from meson_pwm_calc()) may sleep.
Only hold the spin-lock when modifying registers to solve this.

The reason why we need a spin-lock in the driver is because the
REG_MISC_AB register is shared between the two channels provided by one
PWM controller. The only functions where REG_MISC_AB is modified are
meson_pwm_enable() and meson_pwm_disable() so the register reads/writes
in there need to be protected by the spin-lock.

The original code also used the spin-lock to protect the values in
struct meson_pwm_channel. This could be necessary if two consumers can
use the same PWM channel. However, PWM core doesn't allow this so we
don't need to protect the values in struct meson_pwm_channel with a
lock.

Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22 08:17:13 +02:00
Vignesh R
8001317c0b pwm: tiehrpwm: Fix disabling of output of PWMs
commit 38dabd91ff0bde33352ca3cc65ef515599b77a05 upstream.

pwm-tiehrpwm driver disables PWM output by putting it in low output
state via active AQCSFRC register in ehrpwm_pwm_disable(). But, the
AQCSFRC shadow register is not updated. Therefore, when shadow AQCSFRC
register is re-enabled in ehrpwm_pwm_enable() (say to enable second PWM
output), previous settings are lost as shadow register value is loaded
into active register. This results in things like PWMA getting enabled
automatically, when PWMB is enabled and vice versa. Fix this by
updating AQCSFRC shadow register as well during ehrpwm_pwm_disable().

Fixes: 19891b20e7c2 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Cc: stable@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-09 20:01:25 +02:00
Hans de Goede
037aca0e2f pwm: lpss: platform: Save/restore the ctrl register over a suspend/resume
commit 1d375b58c12f08d8570b30b865def4734517f04f upstream.

On some devices the contents of the ctrl register get lost over a
suspend/resume and the PWM comes back up disabled after the resume.

This is seen on some Bay Trail devices with the PWM in ACPI enumerated
mode, so it shows up as a platform device instead of a PCI device.

If we still think it is enabled and then try to change the duty-cycle
after this, we end up with a "PWM_SW_UPDATE was not cleared" error and
the PWM is stuck in that state from then on.

This commit adds suspend and resume pm callbacks to the pwm-lpss-platform
code, which save/restore the ctrl register over a suspend/resume, fixing
this.

Note that:

1) There is no need to do this over a runtime suspend, since we
only runtime suspend when disabled and then we properly set the enable
bit and reprogram the timings when we re-enable the PWM.

2) This may be happening on more systems then we realize, but has been
covered up sofar by a bug in the acpi-lpss.c code which was save/restoring
the regular device registers instead of the lpss private registers due to
lpss_device_desc.prv_offset not being set. This is fixed by a later patch
in this series.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03 11:23:16 +02:00
Ryo Kodama
f6ed0ff4c7 pwm: rcar: Fix a condition to prevent mismatch value setting to duty
commit 6225f9c64b40bc8a22503e9cda70f55d7a9dd3c6 upstream.

This patch fixes an issue that is possible to set mismatch value to duty
for R-Car PWM if we input the following commands:

 # cd /sys/class/pwm/<pwmchip>/
 # echo 0 > export
 # cd pwm0
 # echo 30 > period
 # echo 30 > duty_cycle
 # echo 0 > duty_cycle
 # cat duty_cycle
 0
 # echo 1 > enable
 --> Then, the actual duty_cycle is 30, not 0.

So, this patch adds a condition into rcar_pwm_config() to fix this
issue.

Signed-off-by: Ryo Kodama <ryo.kodama.vz@renesas.com>
[shimoda: revise the commit log and add Fixes and Cc tags]
Fixes: ed6c1476bf7f ("pwm: Add support for R-Car PWM Timer")
Cc: Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-24 09:34:14 +02:00
Axel Lin
93f092f2c3 pwm: stmpe: Fix wrong register offset for hwpwm=2 case
[ Upstream commit 8472b529e113e0863ea064fdee51bf73c3f86fd6 ]

Fix trivial copy/paste bug.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Fixes: ef1f09eca74a ("pwm: Add a driver for the STMPE PWM")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 09:17:55 +01:00
Laxman Dewangan
99f3e3b0a8 pwm: tegra: Increase precision in PWM rate calculation
[ Upstream commit 250b76f43f57d578ebff5e7211eb2c73aa5cd6ca ]

The rate of the PWM calculated as follows:

	hz = NSEC_PER_SEC / period_ns;
 	rate = (rate + (hz / 2)) / hz;

This has the precision loss in lower PWM rate.

Change this to have more precision as:

	hz = DIV_ROUND_CLOSEST_ULL(NSEC_PER_SEC * 100, period_ns);
	rate = DIV_ROUND_CLOSEST(rate * 100, hz)

Example:

1. period_ns = 16672000, PWM clock rate is 200 KHz.

	Based on old formula
		hz = NSEC_PER_SEC / period_ns
		   = 1000000000ul/16672000
		   = 59 (59.98)
		rate = (200K + 59/2)/59 = 3390

	Based on new method:
		hz = 5998
		rate = DIV_ROUND_CLOSE(200000*100, 5998) = 3334

	If we measure the PWM signal rate, we will get more accurate
	period with rate value of 3334 instead of 3390.

2.  period_ns = 16803898, PWM clock rate is 200 KHz.

	Based on old formula:
		hz = 59, rate = 3390

	Based on new formula:
		hz = 5951, rate = 3360

	The PWM signal rate of 3360 is more near to requested period
	than 3333.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 09:17:52 +01:00
David Wu
5f48cacaa7 pwm: rockchip: State of PWM clock should synchronize with PWM enabled state
commit a900152b5c29aea8134cc7a4c5db25552b3cd8f7 upstream.

If the PWM was not enabled at U-Boot loader, PWM could not work for
clock always disabled at PWM driver. The PWM clock is enabled at
beginning of pwm_apply(), but disabled at end of pwm_apply().

If the PWM was enabled at U-Boot loader, PWM clock is always enabled
unless closed by ATF. The pwm-backlight might turn off the power at
early suspend, should disable PWM clock for saving power consume.

It is important to provide opportunity to enable/disable clock at PWM
driver, the PWM consumer should ensure correct order to call PWM enable
and disable, and PWM driver ensure state of PWM clock synchronized with
PWM enabled state.

Fixes: 2bf1c98aa5a4 ("pwm: rockchip: Add support for atomic update")
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21 09:31:22 +02:00
Clemens Gruber
019c088dc4 pwm: pca9685: Fix period change with same duty cycle
commit 8d254a340efb12b40c4c1ff25a48a4f48f7bbd6b upstream.

When first implementing support for changing the output frequency, an
optimization was added to continue the PWM after changing the prescaler
without having to reprogram the ON and OFF registers for the duty cycle,
in case the duty cycle stayed the same. This was flawed, because we
compared the absolute value of the duty cycle in nanoseconds instead of
the ratio to the period.

Fix the problem by removing the shortcut.

Fixes: 01ec8472009c9 ("pwm-pca9685: Support changing the output frequency")
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15 10:02:46 +08:00
Johan Hovold
0e1614ac84 pwm: Fix device reference leak
Make sure to drop the reference to the parent device taken by
class_find_device() after "unexporting" any children when deregistering
a PWM chip.

Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-11-29 16:43:24 +01:00
Axel Lin
c699995663 pwm: meson: Add missing spin_lock_init()
The driver uses the spin_lock but does not initialize it. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-10-21 09:10:11 +02:00
Thierry Reding
dc8e6e1e8f Merge branch 'for-4.9/drivers' into for-next 2016-09-08 10:59:30 +02:00
Arnd Bergmann
2fbc487df6 pwm: meson: Handle unknown ID values
When building with -Wmaybe-uninitialized, we get a couple of harmless
warnings about three functions in this new driver that don't look
safe to the compiler:

drivers/pwm/pwm-meson.c: In function 'meson_pwm_get_state':
drivers/pwm/pwm-meson.c:355:26: error: 'mask' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c: In function 'meson_pwm_disable':
drivers/pwm/pwm-meson.c:263:13: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c: In function 'meson_pwm_apply':
drivers/pwm/pwm-meson.c:231:13: error: 'clk_shift' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c:231:36: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c:231:24: error: 'clk_enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Specifically, if we have a device with an ID other than 0 or 1,
this would result in undefined behavior. This is currently not
possible, but the compiler cannot be expected to know this.

This patch adds a 'default' clause to let the compiler know
what to do instead, which shuts up the warning and makes the
code slightly more resiliant in case it gets extended to other
identifiers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:58:33 +02:00
Lee Jones
7d8a600c91 pwm: sti: Take the opportunity to conduct a little house keeping
This includes fixing some Coding Style issues and re-ordering and/or
simplifying a little code.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
[thierry.reding@gmail.com: applied some bikeshedding>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:12 +02:00
Lee Jones
85a834c42a pwm: sti: It's now valid for number of PWM channels to be zero
Setting up the STI PWM IP as capture only, with zero PWM output devices
is a perfectly valid configuration. It is no longer okay to assume that
there must be at least 1 PWM output device. In this patch we make the
default number of PWM output devices zero and only configure channels
explicitly requested.

Reported-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:11 +02:00
Lee Jones
c97267ae83 pwm: sti: Add PWM capture callback
Once a PWM capture has been initiated, the capture call enables a rising
edge detection interrupt, then waits. Once each of the 3 phase changes
have been recorded the thread then wakes. The remaining part of the call
carries out the relevant calculations and returns a structure filled out
with the capture data.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:11 +02:00
Lee Jones
25eb538096 pwm: sti: Add support for PWM capture interrupts
Here we're requesting the PWM capture IRQ and supplying the handler that
will be called in the event of an interrupt to handle it.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:10 +02:00
Lee Jones
3f0925b5a8 pwm: sti: Initialise PWM capture device data
Each PWM capture device is allocated a structure to hold its own state.
During a capture the device may be partaking in one of 3 phases. Initial
(rising) phase change, a subsequent (falling) phase change indicating
end of the duty-cycle phase and finally a final (rising) phase change
indicating the end of the period. The timer value snapshot each event is
held in a variable of the same name, and the phase number (0, 1, 2) is
contained in the index variable. Other device specific information, such
as GPIO pin, the IRQ wait queue and locking is also contained in the
structure. This patch initialises this structure for each of the
available devices.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:09 +02:00
Lee Jones
d66a928dc0 pwm: sti: Supply PWM Capture clock handling
ST's PWM IP is supplied by 2 different clocks. One for PWM output and
the other for capture. This patch provides clock handling for the
latter.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:09 +02:00
Lee Jones
f66d78faf2 pwm: sti: Supply PWM capture register addresses and bit locations
This is in preparation for subsequent patches that add support for PWM
capture to this driver.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:08 +02:00
Lee Jones
d81738b76f pwm: sti: Only request clock rate when needed
In the original code the clock rate was only obtained during
initialisation; however, the rate may change between then and
its use.  This patch ensures the correct rate is acquired just
before use.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:08 +02:00
Lee Jones
c5f94ae639 pwm: sti: Reorganise register names in preparation for new functionality
Exciting functionality is on the way to this device.  But
before we can add it, we need to do some basic housekeeping
so the additions can be added cleanly.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:07 +02:00
Lee Jones
09022e61d5 pwm: sti: Rename channel => device
This is to bring the terminology used in the STi PWM driver more
into line with the PWM subsystem.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:07 +02:00
oliver@schinagl.nl
fe0e2cf931 pwm: lpc-18xx: use pwm_set_chip_data
The lpc-18xx driver currently manipulates the pwm_device struct directly
rather than using the pwm_set_chip_data() function. While the current
method may save a clock cycle or two, using the explicit function call
makes it more obvious that data is set to the local chip data pointer.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Reviewed-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:05 +02:00
Milo Kim
42ddcf4f9e pwm: sunxi: Add H3 support
H3 PWM controller has same register layout as sun4i driver, so it works
by adding H3 specific data.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: linux-pwm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Milo Kim <woogyom.kim@gmail.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:05 +02:00
Neil Armstrong
211ed63075 pwm: Add support for Meson PWM Controller
Add support for the PWM controller found in the Amlogic SoCs. This
driver supports the Meson8b and GXBB SoCs.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:00 +02:00
Seung-Woo Kim
04d68dea26 pwm: samsung: Fix to use lowest div for large enough modulation bits
From pwm_samsung_calc_tin(), there is routine to find the lowest divider
possible to generate lower frequency than requested one. But it is
always possible to generate requested frequency with large enough
modulation bits except on s3c24xx, so this patch fixes to use lowest div
for the case. This patch removes following UBSAN warning:

   UBSAN: Undefined behaviour in drivers/pwm/pwm-samsung.c:197:13
   shift exponent 32 is too large for 32-bit type 'long unsigned int'
   [...]
   [<c0670248>] (ubsan_epilogue) from [<c06707b4>] (__ubsan_handle_shift_out_of_bounds+0xd8/0x120)
   [<c06707b4>] (__ubsan_handle_shift_out_of_bounds) from [<c0694b28>] (pwm_samsung_config+0x508/0x6a4)
   [<c0694b28>] (pwm_samsung_config) from [<c069286c>] (pwm_apply_state+0x174/0x40c)
   [<c069286c>] (pwm_apply_state) from [<c0b2e070>] (pwm_fan_probe+0xc8/0x488)
   [<c0b2e070>] (pwm_fan_probe) from [<c07ba8b0>] (platform_drv_probe+0x70/0x150)
   [...]

Cc: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:55 +02:00
Jyri Sarha
549c50af25 pwm: pwm-tipwmss: Remove all runtime PM gets/puts
Remove all pm_runtime_get_sync() and pm_runtime_put_sync() call as well
as the dummy pm_ops from the pwm-tipwmss driver. No registers are being
modified. The runtime PM still needs to be enabled, so that the runtime
PM framework can take care of enabling/disabling the PWMSS clock when
submodules of PWMSS (ECAP or EHRPWM) call runtime PM APIs. With this
change PWMSS clock goes to idle when none of the submodules are in use.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:54 +02:00
Brian Norris
065cfbbb63 pwm: cros-ec: Add __packed to prevent padding
While the particular usage in question is likely safe (struct
cros_ec_command is 32-bit aligned, followed by <= 32-bit fields), it's
been suggested this is not a great pattern to follow for the general
case -- for example, if we follow a 'struct cros_ec_command' (which is
32-bit- but not 64-bit-aligned) with a struct that starts with a 64-bit
type (e.g., u64), the compiler may add padding.

Let's add __packed, to inform the compiler of our true intention -- to
have no padding between these struct elements -- and to future proof for
any refactorings that might occur.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:54 +02:00
Weiqing Kong
cd4b45ac44 pwm: Add MediaTek MT2701 display PWM driver support
Use the mtk_pwm_data struction to define different registers
and add MT2701 specific register operations, such as MT2701
doesn't have commit register, needs to disable double buffer
before writing register, and needs to select manual mode
and use PWM_PERIOD/PWM_HIGH_WIDTH.

Signed-off-by: Weiqing Kong <weiqing.kong@mediatek.com>
[thierry.reding@gmail.com: use of_device_get_match_data()]
[thierry.reding@gmail.com: parameterize more consistently]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:53 +02:00
Jisheng Zhang
bbf0722c1c pwm: berlin: Add suspend/resume support
This patch adds suspend-to-RAM support to the Berlin PWM driver.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:52 +02:00
David Hsu
0733424c9b pwm: Unexport children before chip removal
Exported pwm channels aren't removed before the pwmchip and are
leaked. This results in invalid sysfs files. This fix removes
all exported pwm channels before chip removal.

Signed-off-by: David Hsu <davidhsu@google.com>
Fixes: 76abbdde2d95 ("pwm: Add sysfs interface")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-05 16:45:39 +02:00
Paul Kocialkowski
45c0ce847a pwm: twl: Reliably disable TWL6030 PWMs
The current TWL6030 code for the TWL PWM driver does not reliably disable the
PWM output, as tested with LEDs. The previous commit to that driver introduced
that regression.

However, it does make sense to disable the PWM clock after resetting the PWM,
but for some obscure reason, doing it all at once simply doesn't work.

The TWL6030 datasheet mentions that PWMs have to be disabled in two distinct
steps. However, clearing the clock enable bit in a second step (after issuing a
reset first) does not work.

The only approach that works is the one that was in place before the previous
commit to the driver. It consists in enabling the PWM clock after issuing a
reset. This is what TI kernel trees and production code seem to be using.

However, adding an extra step to disable the PWM clock seems to work reliably,
despite looking quite odd.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-05 07:13:47 +02:00