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| author | Hans de Goede <hdegoede@redhat.com> | 2020-09-03 13:23:27 +0200 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2020-09-06 15:38:01 +0200 |
| commit | 547d9e9261d294f0a2597d9e9c55ba48f80716ab (patch) | |
| tree | ceb7f144da1e93e5172336a1e9ba5493bef654a3 | |
| parent | d6d54bacb1dd02a31ed9d8e3db028639da292615 (diff) | |
| download | lwn-547d9e9261d294f0a2597d9e9c55ba48f80716ab.tar.gz lwn-547d9e9261d294f0a2597d9e9c55ba48f80716ab.zip | |
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
| -rw-r--r-- | drivers/pwm/pwm-lpss-platform.c | 1 | ||||
| -rw-r--r-- | drivers/pwm/pwm-lpss.c | 24 | ||||
| -rw-r--r-- | drivers/pwm/pwm-lpss.h | 3 |
3 files changed, 0 insertions, 28 deletions
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c index 48f34d20aecd..c6502cf7a7af 100644 --- a/drivers/pwm/pwm-lpss-platform.c +++ b/drivers/pwm/pwm-lpss-platform.c @@ -89,7 +89,6 @@ static int pwm_lpss_prepare(struct device *dev) static const struct dev_pm_ops pwm_lpss_platform_pm_ops = { .prepare = pwm_lpss_prepare, - SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume) }; static const struct acpi_device_id pwm_lpss_acpi_match[] = { diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index 9c5c7217c9b6..3444c56b4bed 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -260,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm) } EXPORT_SYMBOL_GPL(pwm_lpss_remove); -int pwm_lpss_suspend(struct device *dev) -{ - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); - int i; - - for (i = 0; i < lpwm->info->npwm; i++) - lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM); - - return 0; -} -EXPORT_SYMBOL_GPL(pwm_lpss_suspend); - -int pwm_lpss_resume(struct device *dev) -{ - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); - int i; - - for (i = 0; i < lpwm->info->npwm; i++) - writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM); - - return 0; -} -EXPORT_SYMBOL_GPL(pwm_lpss_resume); - MODULE_DESCRIPTION("PWM driver for Intel LPSS"); MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); MODULE_LICENSE("GPL v2"); diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h index 7909fa12fca2..70db7e389d66 100644 --- a/drivers/pwm/pwm-lpss.h +++ b/drivers/pwm/pwm-lpss.h @@ -19,7 +19,6 @@ struct pwm_lpss_chip { struct pwm_chip chip; void __iomem *regs; const struct pwm_lpss_boardinfo *info; - u32 saved_ctrl[MAX_PWMS]; }; struct pwm_lpss_boardinfo { @@ -37,7 +36,5 @@ struct pwm_lpss_boardinfo { struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, const struct pwm_lpss_boardinfo *info); int pwm_lpss_remove(struct pwm_lpss_chip *lpwm); -int pwm_lpss_suspend(struct device *dev); -int pwm_lpss_resume(struct device *dev); #endif /* __PWM_LPSS_H */ |