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path: root/drivers/gpio/gpiolib-of.c
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Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
-rw-r--r--drivers/gpio/gpiolib-of.c66
1 files changed, 59 insertions, 7 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 42a4bb7cf49a..d22dcc38179d 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -196,21 +196,68 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
}
/**
+ * of_gpiochip_set_names() - set up the names of the lines
+ * @chip: GPIO chip whose lines should be named, if possible
+ */
+static void of_gpiochip_set_names(struct gpio_chip *gc)
+{
+ struct gpio_device *gdev = gc->gpiodev;
+ struct device_node *np = gc->of_node;
+ int i;
+ int nstrings;
+
+ nstrings = of_property_count_strings(np, "gpio-line-names");
+ if (nstrings <= 0)
+ /* Lines names not present */
+ return;
+
+ /* This is normally not what you want */
+ if (gdev->ngpio != nstrings)
+ dev_info(&gdev->dev, "gpio-line-names specifies %d line "
+ "names but there are %d lines on the chip\n",
+ nstrings, gdev->ngpio);
+
+ /*
+ * Make sure to not index beyond the end of the number of descriptors
+ * of the GPIO device.
+ */
+ for (i = 0; i < gdev->ngpio; i++) {
+ const char *name;
+ int ret;
+
+ ret = of_property_read_string_index(np,
+ "gpio-line-names",
+ i,
+ &name);
+ if (ret) {
+ if (ret != -ENODATA)
+ dev_err(&gdev->dev,
+ "unable to name line %d: %d\n",
+ i, ret);
+ break;
+ }
+ gdev->descs[i].name = name;
+ }
+}
+
+/**
* of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
* @chip: gpio chip to act on
*
* This is only used by of_gpiochip_add to request/set GPIO initial
* configuration.
+ * It retures error if it fails otherwise 0 on success.
*/
-static void of_gpiochip_scan_gpios(struct gpio_chip *chip)
+static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
{
struct gpio_desc *desc = NULL;
struct device_node *np;
const char *name;
enum gpio_lookup_flags lflags;
enum gpiod_flags dflags;
+ int ret;
- for_each_child_of_node(chip->of_node, np) {
+ for_each_available_child_of_node(chip->of_node, np) {
if (!of_property_read_bool(np, "gpio-hog"))
continue;
@@ -218,9 +265,12 @@ static void of_gpiochip_scan_gpios(struct gpio_chip *chip)
if (IS_ERR(desc))
continue;
- if (gpiod_hog(desc, name, lflags, dflags))
- continue;
+ ret = gpiod_hog(desc, name, lflags, dflags);
+ if (ret < 0)
+ return ret;
}
+
+ return 0;
}
/**
@@ -440,11 +490,13 @@ int of_gpiochip_add(struct gpio_chip *chip)
if (status)
return status;
- of_node_get(chip->of_node);
+ /* If the chip defines names itself, these take precedence */
+ if (!chip->names)
+ of_gpiochip_set_names(chip);
- of_gpiochip_scan_gpios(chip);
+ of_node_get(chip->of_node);
- return 0;
+ return of_gpiochip_scan_gpios(chip);
}
void of_gpiochip_remove(struct gpio_chip *chip)