Re: [PATCH v3 2/2] gpiolib: check the 'ngpios' property in core gpiolib code
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2021-11-24 14:47:13
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On Wed, Nov 24, 2021 at 01:28:50PM +0100, Bartosz Golaszewski wrote:
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.
quoted hunk ↗ jump to hunk
Signed-off-by: Bartosz Golaszewski <redacted> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <redacted> --- v1 -> v2: - use device_property_read_u32() instead of fwnode_property_read_u32() - reverse the error check logic v2 -> v3: - don't shadow errors other than -ENODATA in device_property_read_u32() drivers/gpio/gpiolib.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index ede8b8a7aa18..f79fd2551cf7 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@@ -647,9 +648,17 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, }
if (gc->ngpio == 0) {
- chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
- ret = -EINVAL;
- goto err_free_descs;
+ ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
+ if (ret) {
+ if (ret == -ENODATA) {
+ chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
+ ret = -EINVAL;
+ }
+
+ goto err_free_descs;
+ }
And if the property returns 0 in ngpios?
What about the modified suggestion from previous version:
if (gc->ngpio == 0) {
ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
/*
* -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.
*/
if (ret == -ENODATA)
ngpios = 0;
else if (ret)
return ret;
gc->ngpio = ngpios;
}
if (gc->ngpio == 0) {
chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
ret = -EINVAL;
goto err_free_descs;
}
?
+ gc->ngpio = ngpios; } if (gc->ngpio > FASTPATH_NGPIO) -- 2.25.1
-- With Best Regards, Andy Shevchenko