From 6e69ab1361c44e3ee1398158b56d114b1aef8179 Mon Sep 17 00:00:00 2001
From: Florian Vaussard <florian.vaussard@epfl.ch>
Date: Mon, 28 Jan 2013 15:00:57 +0100
Subject: 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>

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 903138b..ffbef95 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -733,6 +733,18 @@ void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 }
 EXPORT_SYMBOL_GPL(devm_pwm_put);
 
+/**
+  * pwm_can_sleep() - report whether PWM access will sleep
+  * @pwm: PWM device
+  *
+  * It returns true if accessing the PWM can sleep, false otherwise.
+  */
+bool pwm_can_sleep(struct pwm_device *pwm)
+{
+	return pwm->chip->can_sleep;
+}
+EXPORT_SYMBOL_GPL(pwm_can_sleep);
+
 #ifdef CONFIG_DEBUG_FS
 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 {
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 6d661f3..3fef477 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 {
-- 
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