pwm: Add debugfs interface

This commit adds a debugfs interface that can be used to list the
current internal state of the PWM devices registered with the PWM
framework.

Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 57103911f4c7..047cd5351a3b 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -2,6 +2,7 @@
 #define __LINUX_PWM_H
 
 struct pwm_device;
+struct seq_file;
 
 /*
  * pwm_request - request a PWM device
@@ -65,6 +66,7 @@ static inline unsigned int pwm_get_period(struct pwm_device *pwm)
  * @config: configure duty cycles and period length for this PWM
  * @enable: enable PWM output toggling
  * @disable: disable PWM output toggling
+ * @dbg_show: optional routine to show contents in debugfs
  * @owner: helps prevent removal of modules exporting active PWMs
  */
 struct pwm_ops {
@@ -79,6 +81,10 @@ struct pwm_ops {
                                           struct pwm_device *pwm);
         void                    (*disable)(struct pwm_chip *chip,
                                            struct pwm_device *pwm);
+#ifdef CONFIG_DEBUG_FS
+        void                    (*dbg_show)(struct pwm_chip *chip,
+                                            struct seq_file *s);
+#endif
         struct module           *owner;
 };