diff mbox series

[v8,05/17] pwm: lpss: Add pwm_lpss_prepare_enable() helper

Message ID 20200830125753.230420-6-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show
Series acpi/pwm/i915: Convert pwm-crc and i915 driver's PWM code to use the atomic PWM API | expand

Commit Message

Hans de Goede Aug. 30, 2020, 12:57 p.m. UTC 
In the not-enabled -> enabled path pwm_lpss_apply() needs to get a
runtime-pm reference; and then on any errors it needs to release it
again.

This leads to somewhat hard to read code. This commit introduces a new
pwm_lpss_prepare_enable() helper and moves all the steps necessary for
the not-enabled -> enabled transition there, so that we can error check
the entire transition in a single place and only have one pm_runtime_put()
on failure call site.

While working on this I noticed that the enabled -> enabled (update
settings) path was quite similar, so I've added an enable parameter to
the new pwm_lpss_prepare_enable() helper, which allows using it in that
path too.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/pwm/pwm-lpss.c | 45 ++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 19 deletions(-)

Comments

Thierry Reding Aug. 31, 2020, 11:03 a.m. UTC | #1 
On Sun, Aug 30, 2020 at 02:57:41PM +0200, Hans de Goede wrote:
> In the not-enabled -> enabled path pwm_lpss_apply() needs to get a
> runtime-pm reference; and then on any errors it needs to release it
> again.
> 
> This leads to somewhat hard to read code. This commit introduces a new
> pwm_lpss_prepare_enable() helper and moves all the steps necessary for
> the not-enabled -> enabled transition there, so that we can error check
> the entire transition in a single place and only have one pm_runtime_put()
> on failure call site.
> 
> While working on this I noticed that the enabled -> enabled (update
> settings) path was quite similar, so I've added an enable parameter to
> the new pwm_lpss_prepare_enable() helper, which allows using it in that
> path too.
> 
> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/pwm/pwm-lpss.c | 45 ++++++++++++++++++++++++------------------
>  1 file changed, 26 insertions(+), 19 deletions(-)

Acked-by: Thierry Reding <thierry.reding@gmail.com>
diff mbox series

Patch

diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index da9bc3d10104..8a136ba2a583 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -122,41 +122,48 @@  static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
 }
 
+static int pwm_lpss_prepare_enable(struct pwm_lpss_chip *lpwm,
+				   struct pwm_device *pwm,
+				   const struct pwm_state *state,
+				   bool enable)
+{
+	int ret;
+
+	ret = pwm_lpss_is_updating(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+	pwm_lpss_cond_enable(pwm, enable && lpwm->info->bypass == false);
+	ret = pwm_lpss_wait_for_update(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_cond_enable(pwm, enable && lpwm->info->bypass == true);
+	return 0;
+}
+
 static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			  const struct pwm_state *state)
 {
 	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
-	int ret;
+	int ret = 0;
 
 	if (state->enabled) {
 		if (!pwm_is_enabled(pwm)) {
 			pm_runtime_get_sync(chip->dev);
-			ret = pwm_lpss_is_updating(pwm);
-			if (ret) {
-				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
-			ret = pwm_lpss_wait_for_update(pwm);
-			if (ret) {
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state, true);
+			if (ret)
 				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
 		} else {
-			ret = pwm_lpss_is_updating(pwm);
-			if (ret)
-				return ret;
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			return pwm_lpss_wait_for_update(pwm);
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state, false);
 		}
 	} else if (pwm_is_enabled(pwm)) {
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
 		pm_runtime_put(chip->dev);
 	}
 
-	return 0;
+	return ret;
 }
 
 static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,