gpio: pl061: bind pinctrl by gpio request

Add the pl061_gpio_request() to request pinctrl. Create the logic
between pl061 gpio driver and pinctrl (pinctrl-single) driver.

While a gpio pin is requested, it will request pinctrl driver to
set that pin with gpio function mode. So pinctrl driver should
append .gpio_request_enable() in pinmux_ops.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pl061.c

@@ -23,6 +23,7 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/pl061.h>
 #include <linux/slab.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/pm.h>
 #include <asm/mach/irq.h>
 
@@ -60,6 +61,17 @@ struct pl061_gpio {
 #endif
 };
 
+static int pl061_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	/*
+	 * Map back to global GPIO space and request muxing, the direction
+	 * parameter does not matter for this controller.
+	 */
+	int gpio = chip->base + offset;
+
+	return pinctrl_request_gpio(gpio);
+}
+
 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
@@ -274,6 +286,7 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 
 	spin_lock_init(&chip->lock);
 
+	chip->gc.request = pl061_gpio_request;
 	chip->gc.direction_input = pl061_direction_input;
 	chip->gc.direction_output = pl061_direction_output;
 	chip->gc.get = pl061_get_value;