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 */
const char *con_id;
unsigned int idx;
unsigned long flags;
--
2.17.1
