diff options
| author | Brandon Maier <Brandon.Maier@collins.com> | 2018-11-28 11:14:17 -0600 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-12-07 13:37:25 +0100 |
| commit | 6169005ceb8c715582eca70df3912cd2b351ede2 (patch) | |
| tree | c8848eaa47f7dd233d9e952306bc4b9bc414a83d /drivers/gpio | |
| parent | 9904f0325ec3d57b823b4c9cd569eed9fc1ef1f7 (diff) | |
| download | linux-6169005ceb8c715582eca70df3912cd2b351ede2.tar.bz2 | |
gpio: zynq: Report gpio direction at boot
The Zynq's gpios can be configured by the bootloader. But Linux will
erroneously report all gpios as inputs unless we implement
get_direction().
Signed-off-by: Brandon Maier <Brandon.Maier@collins.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-zynq.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c index ac9b02c9598f..b3b4edcdffe0 100644 --- a/drivers/gpio/gpio-zynq.c +++ b/drivers/gpio/gpio-zynq.c @@ -358,6 +358,28 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, } /** + * zynq_gpio_get_direction - Read the direction of the specified GPIO pin + * @chip: gpio_chip instance to be worked on + * @pin: gpio pin number within the device + * + * This function returns the direction of the specified GPIO. + * + * Return: 0 for output, 1 for input + */ +static int zynq_gpio_get_direction(struct gpio_chip *chip, unsigned int pin) +{ + u32 reg; + unsigned int bank_num, bank_pin_num; + struct zynq_gpio *gpio = gpiochip_get_data(chip); + + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio); + + reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + + return !(reg & BIT(bank_pin_num)); +} + +/** * zynq_gpio_irq_mask - Disable the interrupts for a gpio pin * @irq_data: per irq and chip data passed down to chip functions * @@ -825,6 +847,7 @@ static int zynq_gpio_probe(struct platform_device *pdev) chip->free = zynq_gpio_free; chip->direction_input = zynq_gpio_dir_in; chip->direction_output = zynq_gpio_dir_out; + chip->get_direction = zynq_gpio_get_direction; chip->base = of_alias_get_id(pdev->dev.of_node, "gpio"); chip->ngpio = gpio->p_data->ngpio; |