| From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 4.15 032/102] gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags simultaneously | Date | Sat, 3 Mar 2018 22:24:28 +0000 |
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From: Bartosz Golaszewski <brgl@bgdev.pl>
[ Upstream commit 588fc3bceaf81bbd62e18af6f7bd475e01c2b7e8 ]
Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If the hardware actually supports enabling both at the same time the electrical result would be disastrous.
Suggested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- drivers/gpio/gpiolib.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index f6efcf94f6ad..7a5cf5b08c54 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -460,6 +460,15 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) return -EINVAL; + /* + * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If + * the hardware actually supports enabling both at the same time the + * electrical result would be disastrous. + */ + if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && + (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) + return -EINVAL; + /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) && ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || -- 2.14.1
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