This patch adds suspend/resume function support for Renesas the 16-Bit Timer
Pulse Unit (TPU) driver. This has been tested on the Salvator-XS board
with R-Car M3-N and H3 at renesas-drivers-2019-05-21-v5.2-rc1 tag.
I expect this to work on other SoCs.
Test procedure:
- Enable TPU and pin control in DTS.
- Make sure switches { SW29-[1-2] are switched off or
SW31-[1-4] are switched off(only for Salvator-xs) }.
- Exercise userspace PWM control for pwm[2,3]
of /sys/class/pwm/pwmchip1/ .
- Inspect PWM signals on the input side of { CN29-[58,60]
or SW31-[1,2] (only for Salvator-xs) }
before and after suspend/resume using an oscilloscope.
Signed-off-by: Cao Van Dong <cv-dong@xxxxxxxxxxx>
Tested-by: Cao Van Dong <cv-dong@xxxxxxxxxxx>
---
Changes v3 -> v4:
- Use pwm_is_enabled(pwm) to check channel instead of pwm_get_chip_data(&chip->pwms[i]).
- Move tpu_pwm_disable() to tpu_pwm_suspend(), tpu_pwm_enable() to tpu_pwm_resume().
- Remove tpu_pwm_restart_timer() function and remove pm_runtime_get_sync() in tpu_pwm_resume().
---
Changes v2 -> v3:
- Changes '3' -> TPU_CHANNEL_MAX in loop.
- Remove pm_runtime_put() function in tpu_pwm_suspend() function.
---
Changes v1 -> v2:
- Repair the handling code to cover case of using multiple timers.
---
drivers/pwm/pwm-renesas-tpu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c
index 4a855a2..3c2819b 100644
--- a/drivers/pwm/pwm-renesas-tpu.c
+++ b/drivers/pwm/pwm-renesas-tpu.c
@@ -366,6 +366,47 @@ static void tpu_pwm_disable(struct pwm_chip *chip, struct pwm_device *_pwm)
tpu_pwm_timer_stop(pwm);
}
+#ifdef CONFIG_PM_SLEEP
+static int tpu_pwm_suspend(struct device *dev)
+{
+ struct tpu_device *tpu = dev_get_drvdata(dev);
+ struct pwm_chip *chip = &tpu->chip;
+ struct pwm_device *pwm;
+ int i;
+
+ for (i = 0; i < TPU_CHANNEL_MAX; i++) {
+ pwm = &chip->pwms[i];
+ if (pwm_is_enabled(pwm)) {
+ if (!test_bit(PWMF_REQUESTED, &pwm->flags))
+ return 0;
+ tpu_pwm_disable(pwm->chip,pwm);
+ }
+ }
+
+ return 0;
+}
+
+static int tpu_pwm_resume(struct device *dev)
+{
+ struct tpu_device *tpu = dev_get_drvdata(dev);
+ struct pwm_chip *chip = &tpu->chip;
+ struct pwm_device *pwm;
+ int i;
+
+ for (i = 0; i < TPU_CHANNEL_MAX; i++) {
+ pwm = &chip->pwms[i];
+ if (pwm_is_enabled(pwm)) {
+ if (!test_bit(PWMF_REQUESTED, &pwm->flags))
+ return 0;
+ tpu_pwm_enable(pwm->chip,pwm);
+ }
+ }
+
+ return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+static SIMPLE_DEV_PM_OPS(tpu_pwm_pm_ops, tpu_pwm_suspend, tpu_pwm_resume);
+
static const struct pwm_ops tpu_pwm_ops = {
.request = tpu_pwm_request,
.free = tpu_pwm_free,
@@ -459,6 +500,7 @@ static struct platform_driver tpu_driver = {
.remove = tpu_remove,
.driver = {
.name = "renesas-tpu-pwm",
+ .pm = &tpu_pwm_pm_ops,
.of_match_table = of_match_ptr(tpu_of_table),
}
};
--
2.7.4
