From: Brandon Maier Date: Wed, 28 Nov 2018 17:14:17 +0000 (-0600) Subject: gpio: zynq: Report gpio direction at boot X-Git-Tag: v5.0-rc1~103^2~21 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=6169005ceb8c715582eca70df3912cd2b351ede2;p=linux.git 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 Tested-by: Michal Simek Signed-off-by: Linus Walleij --- 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 @@ -357,6 +357,28 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, return 0; } +/** + * 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;