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 <[email protected]> --- This patch is based on discussion on series Re: [PATCH V5 0/4] gpio: tegra: Cleanups and support for debounce >From Linus W: It would be nice if you also implement .get_direction() which makes debugfs and initial reading of the state of the lines more accurate. V1->V2: - Rearrange the calls to optimise the register access and avoid much indenting based on Stephen's and Jon review. drivers/gpio/gpio-tegra.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c index b3ddd92..ec891a27 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; -- 2.1.4
