led: gpio: Use NOP uclass driver for top-level node

The top level DT node of gpio-leds is not a LED itself, bind NOP uclass
driver to it, and bind different LED uclass driver to its subnodes which
represent the actual LEDs. This simplifies the probe() implementation
and fixes the bogus top-level not-an-LED in 'led list' command output:

```
=> led list
led             Error -121 <--- This is removed/fixed by this patch
green:user0     off
```

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Steven Lawrance <steven.lawrance@softathome.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Tested-by: Patrice Chotard <patrice.chotard@foss.st.com>

diff --git a/drivers/led/led_gpio.c b/drivers/led/led_gpio.c
index 2315690..fbed151 100644 (file)
--- a/drivers/led/led_gpio.c
+++ b/drivers/led/led_gpio.c
@@ -58,17 +58,8 @@ static enum led_state_t gpio_led_get_state(struct udevice *dev)
 static int led_gpio_probe(struct udevice *dev)
 {
        struct led_gpio_priv *priv = dev_get_priv(dev);
-       int ret;
-
-       /* Ignore the top-level LED node */
-       if (device_is_compatible(dev, "gpio-leds"))
-               return 0;
-
-       ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
-       if (ret)
-               return ret;
 
-       return 0;
+       return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
 }
 
 static int led_gpio_remove(struct udevice *dev)
@@ -109,18 +100,23 @@ static const struct led_ops gpio_led_ops = {
        .get_state      = gpio_led_get_state,
 };
 
-static const struct udevice_id led_gpio_ids[] = {
-       { .compatible = "gpio-leds" },
-       { }
-};
-
 U_BOOT_DRIVER(led_gpio) = {
        .name   = "gpio_led",
        .id     = UCLASS_LED,
-       .of_match = led_gpio_ids,
        .ops    = &gpio_led_ops,
        .priv_auto      = sizeof(struct led_gpio_priv),
-       .bind   = led_gpio_bind,
        .probe  = led_gpio_probe,
        .remove = led_gpio_remove,
 };
+
+static const struct udevice_id led_gpio_ids[] = {
+       { .compatible = "gpio-leds" },
+       { }
+};
+
+U_BOOT_DRIVER(led_gpio_wrap) = {
+       .name   = "gpio_led_wrap",
+       .id     = UCLASS_NOP,
+       .of_match = led_gpio_ids,
+       .bind   = led_gpio_bind,
+};