From: Tapio Reijonen Date: Mon, 15 Jun 2026 06:38:40 +0000 (+0000) Subject: serial: max310x: implement gpio_chip::get_direction() X-Git-Tag: v7.2-rc3~4^2~5 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a483b1a91b33b7533280e7c3efd2bc1275caef18;p=thirdparty%2Fkernel%2Flinux.git serial: max310x: implement gpio_chip::get_direction() It's strongly recommended for GPIO drivers to always implement the .get_direction() callback - even when the direction is tracked in software. The GPIO core emits a warning when the callback is missing and a user reads the direction of a line, e.g. via /sys/kernel/debug/gpio. The MAX310X keeps the GPIO direction in the GPIOCFG register (a set bit selects output), which the existing direction_input/output callbacks already program, so the current direction can be read back directly. Fixes: f65444187a66 ("serial: New serial driver MAX310X") Cc: stable Signed-off-by: Tapio Reijonen Reviewed-by: Linus Walleij Reviewed-by: Bartosz Golaszewski Reviewed-by: Hugo Villeneuve Link: https://patch.msgid.link/20260615-b4-serial-max310x-gpio-get-direction-v2-1-4704ba2b181a@vaisala.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index e28e3065c99d..92af02a39c7a 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -1244,6 +1244,17 @@ static int max310x_gpio_set(struct gpio_chip *chip, unsigned int offset, return 0; } +static int max310x_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + struct max310x_port *s = gpiochip_get_data(chip); + struct uart_port *port = &s->p[offset / 4].port; + unsigned int val; + + val = max310x_port_read(port, MAX310X_GPIOCFG_REG); + + return val & BIT(offset % 4) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN; +} + static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) { struct max310x_port *s = gpiochip_get_data(chip); @@ -1447,6 +1458,7 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty s->gpio.owner = THIS_MODULE; s->gpio.parent = dev; s->gpio.label = devtype->name; + s->gpio.get_direction = max310x_gpio_get_direction; s->gpio.direction_input = max310x_gpio_direction_input; s->gpio.get = max310x_gpio_get; s->gpio.direction_output= max310x_gpio_direction_output;