pwm: lpss: Add pwm_lpss_prepare_enable() helper

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>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-6-hdegoede@redhat.com

diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index da9bc3d10104a61239cee931bfee7876b0ccd8cd..8a136ba2a583198a54f246c906b7f744424d4d8e 100644 (file)
--- 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,