UPSTREAM: pwm: Introduce the pwm_args concept

[firefly-linux-kernel-4.4.55.git] / include / linux / pwm.h

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index cfc3ed46cad20a26ffa131b51e25927ac6045f4c..f4120e495f697b0d5e882b8252ea2854a825da43 100644 (file)
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -74,6 +74,24 @@ enum pwm_polarity {
        PWM_POLARITY_INVERSED,
 };
 
+/**
+ * struct pwm_args - board-dependent PWM arguments
+ * @period: reference period
+ * @polarity: reference polarity
+ *
+ * This structure describes board-dependent arguments attached to a PWM
+ * device. These arguments are usually retrieved from the PWM lookup table or
+ * device tree.
+ *
+ * Do not confuse this with the PWM state: PWM arguments represent the initial
+ * configuration that users want to use on this PWM device rather than the
+ * current PWM hardware state.
+ */
+struct pwm_args {
+       unsigned int period;
+       enum pwm_polarity polarity;
+};
+
 enum {
        PWMF_REQUESTED = 1 << 0,
        PWMF_ENABLED = 1 << 1,
@@ -92,6 +110,7 @@ enum {
  * @period: period of the PWM signal (in nanoseconds)
  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
  * @polarity: polarity of the PWM signal
+ * @args: PWM arguments
  */
 struct pwm_device {
        const char *label;
@@ -105,6 +124,8 @@ struct pwm_device {
        unsigned int period;
        unsigned int duty_cycle;
        enum pwm_polarity polarity;
+
+       struct pwm_args args;
 };
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
@@ -144,6 +165,18 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
        return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
 }
 
+static inline void pwm_get_args(const struct pwm_device *pwm,
+                               struct pwm_args *args)
+{
+       *args = pwm->args;
+}
+
+static inline void pwm_apply_args(struct pwm_device *pwm)
+{
+       pwm_set_period(pwm, pwm->args.period);
+       pwm_set_polarity(pwm, pwm->args.polarity);
+}
+
 /**
  * struct pwm_ops - PWM controller operations
  * @request: optional hook for requesting a PWM
@@ -331,6 +364,7 @@ static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
 #ifdef CONFIG_PWM_SYSFS
 void pwmchip_sysfs_export(struct pwm_chip *chip);
 void pwmchip_sysfs_unexport(struct pwm_chip *chip);
+void pwmchip_sysfs_unexport_children(struct pwm_chip *chip);
 #else
 static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 {
@@ -339,6 +373,10 @@ static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 {
 }
+
+static inline void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
+{
+}
 #endif /* CONFIG_PWM_SYSFS */
 
 #endif /* __LINUX_PWM_H */