pinctrl: at91-pio4: allow gpio subsytem to request gpios

gpiolib requests are no longer ignored. Be careful that the strict
mode is not enabled. As a conseguence, gpio requests can overlap
peripheral pinmuxing.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>

Author: ldesroches

drivers/pinctrl/pinctrl-at91-pio4.c

@@ -357,6 +357,8 @@ static int atmel_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 }
 
 static struct gpio_chip atmel_gpio_chip = {
+	.request		= gpiochip_generic_request,
+	.free			= gpiochip_generic_free,
 	.direction_input        = atmel_gpio_direction_input,
 	.get                    = atmel_gpio_get,
 	.direction_output       = atmel_gpio_direction_output,
@@ -643,11 +645,27 @@ static int atmel_pmx_set_mux(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
+static int atmel_pmx_gpio_request_enable(struct pinctrl_dev *pctldev,
+					 struct pinctrl_gpio_range *range,
+					 unsigned offset)
+{
+	u32 conf;
+
+	conf = atmel_pin_config_read(pctldev, offset);
+	conf &= (~ATMEL_PIO_CFGR_FUNC_MASK);
+	atmel_pin_config_write(pctldev, offset, conf);
+
+	dev_dbg(pctldev->dev, "enable pin %u as GPIO\n", offset);
+
+	return 0;
+}
+
 static const struct pinmux_ops atmel_pmxops = {
 	.get_functions_count	= atmel_pmx_get_functions_count,
 	.get_function_name	= atmel_pmx_get_function_name,
 	.get_function_groups	= atmel_pmx_get_function_groups,
 	.set_mux		= atmel_pmx_set_mux,
+	.gpio_request_enable	= atmel_pmx_gpio_request_enable,
 };
 
 static int atmel_conf_pin_config_group_get(struct pinctrl_dev *pctldev,