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author | Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> | 2018-09-21 12:36:03 +0200 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2018-09-25 09:34:48 +0200 |
commit | ae9847f48a4b4bff0335da20be63ac84d94eb54c (patch) | |
tree | ad76987a49c41717745779be2be1b3eb9ae34870 /drivers/gpio | |
parent | 32d064a16eaace1866610f36fb5f4b114d979246 (diff) | |
download | linux-stable-ae9847f48a4b4bff0335da20be63ac84d94eb54c.tar.gz linux-stable-ae9847f48a4b4bff0335da20be63ac84d94eb54c.tar.bz2 linux-stable-ae9847f48a4b4bff0335da20be63ac84d94eb54c.zip |
gpiolib: Fix gpio_direction_* for single direction GPIOs
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>
Diffstat (limited to 'drivers/gpio')
-rw-r--r-- | drivers/gpio/gpiolib.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 1ffd3fb88466..cabe1b460458 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2543,19 +2543,27 @@ 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); @@ -2577,16 +2585,28 @@ 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); |