pwm: lpss: Add support for runtime PM
To be able to save some power when PWM is not in use, add support for
runtime PM for this driver. This also allows the platform to transition to
low power S0ix states when the system is idle.
Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index df03b50..2504410 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -16,6 +16,7 @@
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/pm_runtime.h>
#include "pwm-lpss.h"
@@ -105,6 +106,8 @@
duty_ns = 1;
on_time_div = 255 - (255 * duty_ns / period_ns);
+ pm_runtime_get_sync(chip->dev);
+
ctrl = pwm_lpss_read(pwm);
ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK);
ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT;
@@ -113,11 +116,14 @@
ctrl |= PWM_SW_UPDATE;
pwm_lpss_write(pwm, ctrl);
+ pm_runtime_put(chip->dev);
+
return 0;
}
static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
+ pm_runtime_get_sync(chip->dev);
pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
return 0;
}
@@ -125,6 +131,7 @@
static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
+ pm_runtime_put(chip->dev);
}
static const struct pwm_ops pwm_lpss_ops = {
