drivers/pwm/core: Add support to remove registered consumer lookup tables

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

v2: Ccing maintainers

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>

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index ba34c7d..d2fe7c8 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -586,6 +586,23 @@ void pwm_add_table(struct pwm_lookup *table, size_t num)
 }
 
 /**
+ * pwm_remove_table() - un-register PWM device consumers
+ * @table: array of consumers to un-register
+ * @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
  * @con_id: consumer name

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index e90628c..cfe2d8d 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