[Intel-gfx] [RFC v6 1/8] drivers/gpio/gpiolib: Add support for removing registered consumer lookup table

[Shobhit Kumar]

In case we unload and load a driver module again that is registering a
lookup table, without this it will result in multiple entries. Provide
an option to remove the lookup table on driver unload

v2: Ccing maintainers

Cc: Samuel Ortiz <sameo at linux.intel.com>
Cc: Linus Walleij <linus.walleij at linaro.org>
Cc: Alexandre Courbot <gnurou at gmail.com>
Cc: Thierry Reding <thierry.reding at gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
---
 drivers/gpio/gpiolib.c       | 13 +++++++++++++
 include/linux/gpio/machine.h |  1 +
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 59eaa23..2420af9 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1658,6 +1658,19 @@ void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
 	mutex_unlock(&gpio_lookup_lock);
 }
 
+/**
+ * gpiod_remove_lookup_table() - unregister GPIO device consumers
+ * @table: table of consumers to unregister
+ */
+void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
+{
+	mutex_lock(&gpio_lookup_lock);
+
+	list_del(&table->list);
+
+	mutex_unlock(&gpio_lookup_lock);
+}
+
 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 				      unsigned int idx,
 				      enum gpio_lookup_flags *flags)
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index e270614..c0d712d 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -57,5 +57,6 @@ struct gpiod_lookup_table {
 }
 
 void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
+void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
 
 #endif /* __LINUX_GPIO_MACHINE_H */
-- 
2.1.0