From: Ricardo Ribalda Delgado ricardo.ribalda@gmail.com
[ Upstream commit ae9847f48a4b4bff0335da20be63ac84d94eb54c ]
GPIOs with no programmable direction are not required to implement direction_output nor direction_input.
If we try to set an output direction on an output-only GPIO or input direction on an input-only GPIO simply return 0.
This allows this single direction GPIO to be used by libgpiod.
Signed-off-by: Ricardo Ribalda Delgado ricardo.ribalda@gmail.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 565ab945698ca..b81a27c7f89c4 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2541,19 +2541,27 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); int gpiod_direction_input(struct gpio_desc *desc) { struct gpio_chip *chip; - int status = -EINVAL; + int status = 0;
VALIDATE_DESC(desc); chip = desc->gdev->chip;
- if (!chip->get || !chip->direction_input) { + if (!chip->get && chip->direction_input) { gpiod_warn(desc, - "%s: missing get() or direction_input() operations\n", + "%s: missing get() and direction_input() operations\n", __func__); return -EIO; }
- status = chip->direction_input(chip, gpio_chip_hwgpio(desc)); + if (chip->direction_input) { + status = chip->direction_input(chip, gpio_chip_hwgpio(desc)); + } else if (chip->get_direction && + (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) { + gpiod_warn(desc, + "%s: missing direction_input() operation\n", + __func__); + return -EIO; + } if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags);
@@ -2575,16 +2583,28 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { struct gpio_chip *gc = desc->gdev->chip; int val = !!value; - int ret; + int ret = 0;
- if (!gc->set || !gc->direction_output) { + if (!gc->set && !gc->direction_output) { gpiod_warn(desc, - "%s: missing set() or direction_output() operations\n", + "%s: missing set() and direction_output() operations\n", __func__); return -EIO; }
- ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val); + if (gc->direction_output) { + ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val); + } else { + if (gc->get_direction && + gc->get_direction(gc, gpio_chip_hwgpio(desc))) { + gpiod_warn(desc, + "%s: missing direction_output() operation\n", + __func__); + return -EIO; + } + gc->set(gc, gpio_chip_hwgpio(desc), val); + } + if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_value(desc_to_gpio(desc), 0, val);