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@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v9:
- This is a new patch in v9 of this series
---
drivers/pwm/pwm-lpss-platform.c | 1 -
drivers/pwm/pwm-lpss.c | 24 ------------------------
drivers/pwm/pwm-lpss.h | 3 ---
3 files changed, 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@xxxxxxxxxxxxxxx>");
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 */
--
2.28.0
