pwm: Add pwm_can_sleep() as exported API to users

Calls to some external PWM chips can sleep. To help users,
add pwm_can_sleep() API.

Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 6d661f32e0e4..3fef47733ea3 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -146,6 +146,8 @@ struct pwm_ops {
  * @base: number of first PWM controlled by this chip
  * @npwm: number of PWMs controlled by this chip
  * @pwms: array of PWM devices allocated by the framework
+ * @can_sleep: must be true if the .config(), .enable() or .disable()
+ *             operations may sleep
  */
 struct pwm_chip {
         struct device           *dev;
@@ -159,6 +161,7 @@ struct pwm_chip {
         struct pwm_device *     (*of_xlate)(struct pwm_chip *pc,
                                             const struct of_phandle_args *args);
         unsigned int            of_pwm_n_cells;
+        bool                    can_sleep;
 };
 
 #if IS_ENABLED(CONFIG_PWM)
@@ -179,6 +182,8 @@ void pwm_put(struct pwm_device *pwm);
 
 struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);
 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
+
+bool pwm_can_sleep(struct pwm_device *pwm);
 #else
 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 {
@@ -226,6 +231,11 @@ static inline struct pwm_device *devm_pwm_get(struct device *dev,
 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 {
 }
+
+static inline bool pwm_can_sleep(struct pwm_device *pwm)
+{
+        return false;
+}
 #endif
 
 struct pwm_lookup {