gpiolib: use platform GPIO mappings as fallback
For platforms that use device tree or ACPI as the standard way to look
GPIOs up, allow the platform-defined GPIO mappings to be used as a
fallback. This may be useful for platforms that need extra GPIOs mappings
not defined by the firmware.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b73c39f..dbddace 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2418,7 +2418,7 @@
const char *con_id,
unsigned int idx)
{
- struct gpio_desc *desc;
+ struct gpio_desc *desc = NULL;
int status;
enum gpio_lookup_flags flags = 0;
@@ -2431,9 +2431,19 @@
} else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
desc = acpi_find_gpio(dev, con_id, idx, &flags);
- } else {
+ }
+
+ /*
+ * Either we are not using DT or ACPI, or their lookup did not return
+ * a result. In that case, use platform lookup as a fallback.
+ */
+ if (!desc || IS_ERR(desc)) {
+ struct gpio_desc *pdesc;
dev_dbg(dev, "using lookup tables for GPIO lookup");
- desc = gpiod_find(dev, con_id, idx, &flags);
+ pdesc = gpiod_find(dev, con_id, idx, &flags);
+ /* If used as fallback, do not replace the previous error */
+ if (!IS_ERR(pdesc) || !desc)
+ desc = pdesc;
}
if (IS_ERR(desc)) {