[PATCH] gpio: mxc: implement get_direction callback

[Stefan Wahren <wahrenst@xxxxxxx>]

gpiolib's gpiod_get_direction() function returns an erro if
.get_direction callback is not defined.

The patch implements the callback for IMX platform which is useful
for debugging and also the kernel docs about struct gpio_chip
recommends it.

Inspired by drivers/gpio/gpio-mxs.c

Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
---
 drivers/gpio/gpio-mxc.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index 4cb455b2bdee..ad8a4c73d47b 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -418,6 +418,18 @@ static void mxc_update_irq_chained_handler(struct mxc_gpio_port *port, bool enab
 	}
 }

+static int mxc_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct mxc_gpio_port *port = gpiochip_get_data(gc);
+	u32 dir;
+
+	dir = readl(port->base + GPIO_GDIR);
+	if (dir & BIT(offset))
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
 static int mxc_gpio_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -490,6 +502,7 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 	port->gc.request = mxc_gpio_request;
 	port->gc.free = mxc_gpio_free;
 	port->gc.to_irq = mxc_gpio_to_irq;
+	port->gc.get_direction = mxc_gpio_get_direction;
 	port->gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 :
 					     pdev->id * 32;

--
2.34.1