gpio: add gpio_add_lookup_tables() to add several tables at once

When converting legacy board to use gpiod API() there might be several
lookup tables in board file, let's provide a way to register them all at
once.
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.c

@@ -3010,6 +3010,23 @@ void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
 
+/**
+ * gpiod_add_lookup_tables() - register GPIO device consumers
+ * @tables: list of tables of consumers to register
+ * @n: number of tables in the list
+ */
+void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
+{
+	unsigned int i;
+
+	mutex_lock(&gpio_lookup_lock);
+
+	for (i = 0; i < n; i++)
+		list_add_tail(&tables[i]->list, &gpio_lookup_list);
+
+	mutex_unlock(&gpio_lookup_lock);
+}
+
 /**
  * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
  * @array_size: number of elements in the descriptor / value arrays

include/linux/gpio/machine.h

@@ -60,11 +60,14 @@ struct gpiod_lookup_table {
 
 #ifdef CONFIG_GPIOLIB
 void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
+void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
 #else
 static inline
 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
 static inline
+void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
+static inline
 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
 #endif