Commit graph

16 commits

Author SHA1 Message Date
Uwe Kleine-König
b6ce2af876 pwm: img: Use only a single idiom to get a runtime PM reference
Currently there are two very similar approaches in use by this driver:
img_pwm_config() uses pm_runtime_get_sync() and calls
pm_runtime_put_autosuspend() in the error path; img_pwm_enable() calls
pm_runtime_resume_and_get() which already puts the reference in its own
error path.

Align pm_runtime usage and use the same idiom in both locations.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-11-17 17:24:28 +01:00
Uwe Kleine-König
0ee11b87c3 pwm: img: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-11-17 17:13:02 +01:00
Uwe Kleine-König
fc3f3f565e pwm: img: Don't check the return code of pwmchip_remove()
pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. Also the
driver core ignores the return value of pwm_imx_tpm_remove().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:51 +02:00
Uwe Kleine-König
c68eb29c8e pwm: img: Don't modify HW state in .remove() callback
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>
2021-09-02 21:38:36 +02:00
Zou Wei
fde25294df pwm: img: Fix PM reference leak in img_pwm_enable()
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>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:53:00 +01:00
Yangtao Li
d574ab62a5 pwm: img: Convert to devm_platform_ioremap_resource()
Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:18:45 +01:00
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
Navid Emamdoost
ca162ce981 pwm: img: Call pm_runtime_put() in pm_runtime_get_sync() failed case
Even in failed case of pm_runtime_get_sync(), the usage_count is
incremented. In order to keep the usage_count with correct value call
appropriate pm_runtime_put().

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:51 +02:00
Thomas Gleixner
84a14ae8c4 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 24 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.162703968@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:19 -07:00
Nathan Chancellor
44481955ea pwm: img: Turn final 'else if' into 'else' in img_pwm_config
When building with -Wsometimes-uninitialized, Clang warns:

drivers/pwm/pwm-img.c:126:13: error: variable 'timebase' is used
uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]

The final else if functions as an else; make that explicit so that Clang
understands that timebase cannot be used uninitialized.

Link: https://github.com/ClangBuiltLinux/linux/issues/400
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-20 12:29:22 +01:00
Ed Blake
e690ae5262 pwm: img: Add runtime PM
Add runtime PM to disable the clocks when the h/w is not in use.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-11-15 10:38:37 +01:00
Ed Blake
a18afce522 pwm: img: Add suspend / resume handling
The power may be disabled during suspend, so implement suspend and
resume callbacks to save and restore register state.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
[thierry.reding@gmail.com: guard using PM_SLEEP instead of PM]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-11-15 10:38:04 +01:00
Wolfram Sang
bea307c16a pwm: img: Test clock rate to avoid division by 0
The clk API may return 0 on clk_get_rate(), so we should check the
result before using it as a divisor.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23 17:11:02 +01:00
Naidu Tellapati
1e70897d0e pwm: img: Impose upper and lower timebase steps value
The PWM hardware on Pistachio platform has a maximum timebase steps
value to 255. To fix it, let's introduce a compatible-specific
data structure to contain the SoC-specific details and use it to
specify a maximum timebase.

Also, let's limit the minimum timebase to 16 steps, to allow a sane
range of duty cycle steps.

Fixes: 277bb6a29e ("pwm: Imagination Technologies PWM DAC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-05-19 16:07:40 +02:00
Naidu Tellapati
277bb6a29e pwm: Imagination Technologies PWM DAC driver
The Pistachio SOC from Imagination Technologies includes a Pulse Width
Modulation DAC which produces 1 to 4 digital bit-outputs which represent
digital waveforms. These PWM outputs are primarily in charge of controlling
backlight LED devices.

Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
Signed-off-by: Sai Masarapu <Sai.Masarapu@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
[thierry.reding: fixup license header as discussed on list]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30 12:16:04 +01:00