From: Brandon Maier Brandon.Maier@collins.com
commit 6169005ceb8c715582eca70df3912cd2b351ede2 upstream
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 Cc: stable stable@vger.kernel.org # 4.19 Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpio-zynq.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c index a9238fb150131..5dec96155814b 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 @@ -829,6 +851,7 @@ 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;