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authorRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>2018-09-21 12:36:03 +0200
committerLinus Walleij <linus.walleij@linaro.org>2018-09-25 09:34:48 +0200
commitae9847f48a4b4bff0335da20be63ac84d94eb54c (patch)
treead76987a49c41717745779be2be1b3eb9ae34870 /drivers/gpio
parent32d064a16eaace1866610f36fb5f4b114d979246 (diff)
downloadlinux-ae9847f48a4b4bff0335da20be63ac84d94eb54c.tar.bz2
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.c36
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);