> On November 27, 2019 at 9:42 AM Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>
>
> Currently GPIOs can only be referred to by GPIO controller and offset in
> GPIO lookup tables.
>
> Add support for looking them up by line name.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> If this is rejected, the GPIO Aggregator documentation and code must be
> updated.
>
> v3:
> - New.
> ---
> drivers/gpio/gpiolib.c | 12 ++++++++++++
> include/linux/gpio/machine.h | 2 +-
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index d24a3d79dcfe69ad..cb608512ad6bbded 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -4475,6 +4475,18 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
> if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
> continue;
>
> + if (p->chip_hwnum == (u16)-1) {
> + desc = gpio_name_to_desc(p->chip_label);
> + if (desc) {
> + *flags = p->flags;
> + return desc;
> + }
> +
> + dev_warn(dev, "cannot find GPIO line %s, deferring\n",
> + p->chip_label);
> + return ERR_PTR(-EPROBE_DEFER);
> + }
> +
> chip = find_chip_by_name(p->chip_label);
>
> if (!chip) {
> diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
> index 1ebe5be05d5f81fa..84c1c097e55eefaf 100644
> --- a/include/linux/gpio/machine.h
> +++ b/include/linux/gpio/machine.h
> @@ -31,7 +31,7 @@ enum gpio_lookup_flags {
> */
> struct gpiod_lookup {
> const char *chip_label;
> - u16 chip_hwnum;
> + u16 chip_hwnum; /* if -1, chip_label is named line */
The magic number "-1" might deserve a #define.
> const char *con_id;
> unsigned int idx;
> unsigned long flags;
> --
> 2.17.1
>
With or without #define,
Reviewed-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
CU
Uli
