gpio: tegra: Implement gpio_get_direction callback

Implement gpio_get_direction() callback for Tegra GPIO.
The direction is only valid if the pin is configured as
GPIO. If pin is not configured in GPIO mode then this
function return error.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index b3ddd92..ec891a2 100644 (file)
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -191,6 +191,21 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
        return 0;
 }
 
+static int tegra_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+       struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+       u32 pin_mask = BIT(GPIO_BIT(offset));
+       u32 cnf, oe;
+
+       cnf = tegra_gpio_readl(tgi, GPIO_CNF(tgi, offset));
+       if (!(cnf & pin_mask))
+               return -EINVAL;
+
+       oe = tegra_gpio_readl(tgi, GPIO_OE(tgi, offset));
+
+       return (oe & pin_mask) ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
+}
+
 static int tegra_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
                                   unsigned int debounce)
 {
@@ -575,6 +590,7 @@ static int tegra_gpio_probe(struct platform_device *pdev)
        tgi->gc.get                     = tegra_gpio_get;
        tgi->gc.direction_output        = tegra_gpio_direction_output;
        tgi->gc.set                     = tegra_gpio_set;
+       tgi->gc.get_direction           = tegra_gpio_get_direction;
        tgi->gc.to_irq                  = tegra_gpio_to_irq;
        tgi->gc.base                    = 0;
        tgi->gc.ngpio                   = tgi->bank_count * 32;