ARM: at91: gpio: implement get_direction

This is needed for gpiod_get_direction().
Otherwise, it returns -EINVAL.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/mach-at91/gpio.c

@@ -49,6 +49,7 @@ static int at91_gpiolib_request(struct gpio_chip *chip, unsigned offset);
 static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
 static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
 static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
+static int at91_gpiolib_get_direction(struct gpio_chip *chip, unsigned offset);
 static int at91_gpiolib_direction_output(struct gpio_chip *chip,
 					 unsigned offset, int val);
 static int at91_gpiolib_direction_input(struct gpio_chip *chip,
@@ -60,6 +61,7 @@ static int at91_gpiolib_to_irq(struct gpio_chip *chip, unsigned offset);
 		.chip = {						\
 			.label		  = name,			\
 			.request	  = at91_gpiolib_request,	\
+			.get_direction    = at91_gpiolib_get_direction, \
 			.direction_input  = at91_gpiolib_direction_input, \
 			.direction_output = at91_gpiolib_direction_output, \
 			.get		  = at91_gpiolib_get,		\
@@ -799,6 +801,17 @@ static int at91_gpiolib_request(struct gpio_chip *chip, unsigned offset)
 	return 0;
 }
 
+static int at91_gpiolib_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
+	void __iomem *pio = at91_gpio->regbase;
+	unsigned mask = 1 << offset;
+	u32 osr;
+
+	osr = __raw_readl(pio + PIO_OSR);
+	return !(osr & mask);
+}
+
 static int at91_gpiolib_direction_input(struct gpio_chip *chip,
 					unsigned offset)
 {