pwm: Add support to remove registered consumer lookup tables

In case some drivers are unloading, they can remove lookup tables which
they had registered during their load time to avoid redundant entries if
loaded again.

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index ba34c7d8904232de070b78d4565377c1fab75740..27cd58d16881265e61e6a1c73f15789189040f23 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -585,6 +585,23 @@ void pwm_add_table(struct pwm_lookup *table, size_t num)
        mutex_unlock(&pwm_lookup_lock);
 }
 
+/**
+ * pwm_remove_table() - unregister PWM device consumers
+ * @table: array of consumers to unregister
+ * @num: number of consumers in table
+ */
+void pwm_remove_table(struct pwm_lookup *table, size_t num)
+{
+       mutex_lock(&pwm_lookup_lock);
+
+       while (num--) {
+               list_del(&table->list);
+               table++;
+       }
+
+       mutex_unlock(&pwm_lookup_lock);
+}
+
 /**
  * pwm_get() - look up and request a PWM device
  * @dev: device for PWM consumer

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index e90628cac8fae57e8a88ecd9f93d2a2f1342b9d5..cfe2d8df5be062ee6d63a60f36e6a5ba84356fad 100644 (file)
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -290,10 +290,15 @@ struct pwm_lookup {
 
 #if IS_ENABLED(CONFIG_PWM)
 void pwm_add_table(struct pwm_lookup *table, size_t num);
+void pwm_remove_table(struct pwm_lookup *table, size_t num);
 #else
 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 {
 }
+
+static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
+{
+}
 #endif
 
 #ifdef CONFIG_PWM_SYSFS