From: Bartosz Golaszewski brgl@bgdev.pl
[ Upstream commit 9dbd1ab20509e85cd3fac9479a00c59e83c08196 ]
Several drivers read the 'ngpios' device property on their own, but since it's defined as a standard GPIO property in the device tree bindings anyway, it's a good candidate for generalization. If the driver didn't set its gc->ngpio, try to read the 'ngpios' property from the GPIO device's firmware node before bailing out.
Signed-off-by: Bartosz Golaszewski brgl@bgdev.pl Suggested-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Stable-dep-of: ec851b23084b ("gpiolib: fix memory leak in gpiochip_setup_dev()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a87c4cd94f7a..b7b5fe151e1a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -599,6 +599,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, int base = gc->base; unsigned int i; int ret = 0; + u32 ngpios;
/* * First: allocate and populate the internal stat container, and @@ -646,6 +647,26 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, goto err_free_dev_name; }
+ /* + * Try the device properties if the driver didn't supply the number + * of GPIO lines. + */ + if (gc->ngpio == 0) { + ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios); + if (ret == -ENODATA) + /* + * -ENODATA means that there is no property found and + * we want to issue the error message to the user. + * Besides that, we want to return different error code + * to state that supplied value is not valid. + */ + ngpios = 0; + else if (ret) + goto err_free_descs; + + gc->ngpio = ngpios; + } + if (gc->ngpio == 0) { chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); ret = -EINVAL;