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

Hans de Goede
2020-08-30T12:59:11Z

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(-)

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,
--
2.28.0