Re: [PATCH v6 06/12] gpiolib: Add gpio_get_property_name_length()

Andy Shevchenko
2024-09-04T13:40:32Z

On Wed, Sep 04, 2024 at 05:00:08PM +0800, Chen-Yu Tsai wrote:
> The I2C device tree component prober needs to get and toggle GPIO lines
> for the components it intends to probe. These components may not use the
> same name for their GPIO lines, so the prober must go through the device
> tree, check each property to see it is a GPIO property, and get the GPIO
> line.
>
> Instead of duplicating the GPIO suffixes, or exporting them to the
> prober to do pattern matching, simply add and export a new function that
> does the pattern matching and returns the length of the GPIO name. The
> caller can then use that to copy out the name if it needs to.

> Andy suggested a much shorter implementation.

No need to have this sentence in the commit message, changelog area is fine.
But if you wish... :-)

> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>

...

> +/**
> + * gpio_get_property_name_length - Returns the GPIO name length from a property name
> + * @propname: name of the property to check
> + *
> + * This function checks if the given property name matches the GPIO property
> + * patterns, and returns the length of the name of the GPIO. The pattern is
> + * "*-<GPIO suffix>" or just "<GPIO suffix>".
> + *
> + * Returns:
> + * The length of the string before '-<GPIO suffix>' if it matches
> + * "*-<GPIO suffix>", or 0 if no name part, just the suffix, or
> + * -EINVAL if the string doesn't match the pattern.

Should be %-EINVAL as we agreed with Bart when I updated GPIOLIB kernel-doc.

> + */

--
With Best Regards,
Andy Shevchenko