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>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index b3ddd922290d..ec891a27952f 100644
--- 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;