diff options
| author | Bartosz Golaszewski <brgl@bgdev.pl> | 2021-12-02 16:40:34 +0300 |
|---|---|---|
| committer | Bartosz Golaszewski <brgl@bgdev.pl> | 2021-12-06 18:02:17 +0300 |
| commit | 9dbd1ab20509e85cd3fac9479a00c59e83c08196 (patch) | |
| tree | eca890f8d15d513e3035e4abd83517cfa9136c2a /drivers/gpio/gpiolib.c | |
| parent | e5ab49cd3d6937b1818b80cb5eb09dc018ae0718 (diff) | |
| download | linux-9dbd1ab20509e85cd3fac9479a00c59e83c08196.tar.xz | |
gpiolib: check the 'ngpios' property in core gpiolib code
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>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index bc5ba52865ec..535eb1b509c1 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; |