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| author | Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2019-08-06 13:41:51 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2019-08-14 10:57:18 +0200 |
| commit | 2c60e6b5c9241b24b8b523fefd3e44fb85622cda (patch) | |
| tree | e0e98cde759d582b45ebd0f331edcf46eda3a1e4 | |
| parent | d45331b00ddb179e291766617259261c112db872 (diff) | |
| download | linux-2c60e6b5c9241b24b8b523fefd3e44fb85622cda.tar.gz linux-2c60e6b5c9241b24b8b523fefd3e44fb85622cda.tar.bz2 linux-2c60e6b5c9241b24b8b523fefd3e44fb85622cda.zip | |
gpiolib: never report open-drain/source lines as 'input' to user-space
If the driver doesn't support open-drain/source config options, we
emulate this behavior when setting the direction by calling
gpiod_direction_input() if the default value is 0 (open-source) or
1 (open-drain), thus not actively driving the line in those cases.
This however clears the FLAG_IS_OUT bit for the GPIO line descriptor
and makes the LINEINFO ioctl() incorrectly report this line's mode as
'input' to user-space.
This commit modifies the ioctl() to always set the GPIOLINE_FLAG_IS_OUT
bit in the lineinfo structure's flags field. Since it's impossible to
use the input mode and open-drain/source options at the same time, we
can be sure the reported information will be correct.
Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20190806114151.17652-1-brgl@bgdev.pl
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index f497003f119c..80a2a2cb673b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1091,9 +1091,11 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW; if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN; + lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN | + GPIOLINE_FLAG_IS_OUT); if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE; + lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE | + GPIOLINE_FLAG_IS_OUT); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; |