[U-Boot] [PATCH 4/8] dm: led: Add support for getting the state of an LED

[Simon Glass]

It is useful to be able to read the LED as well as write it. Add this to
the uclass and update the GPIO driver.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 drivers/led/led-uclass.c | 10 ++++++++++
 drivers/led/led_gpio.c   | 15 +++++++++++++++
 include/led.h            | 16 ++++++++++++++++
 test/dm/led.c            |  2 ++
 4 files changed, 43 insertions(+)

diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c
index b30346913b..ea5fbabadf 100644
--- a/drivers/led/led-uclass.c
+++ b/drivers/led/led-uclass.c
@@ -42,6 +42,16 @@ int led_set_state(struct udevice *dev, enum led_state_t state)
 	return ops->set_state(dev, state);
 }
 
+enum led_state_t led_get_state(struct udevice *dev)
+{
+	struct led_ops *ops = led_get_ops(dev);
+
+	if (!ops->get_state)
+		return -ENOSYS;
+
+	return ops->get_state(dev);
+}
+
 UCLASS_DRIVER(led) = {
 	.id		= UCLASS_LED,
 	.name		= "led",
diff --git a/drivers/led/led_gpio.c b/drivers/led/led_gpio.c
index 8206cb2cf3..789d15600f 100644
--- a/drivers/led/led_gpio.c
+++ b/drivers/led/led_gpio.c
@@ -35,6 +35,20 @@ static int gpio_led_set_state(struct udevice *dev, enum led_state_t state)
 	return dm_gpio_set_value(&priv->gpio, state);
 }
 
+static enum led_state_t gpio_led_get_state(struct udevice *dev)
+{
+	struct led_gpio_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	if (!dm_gpio_is_valid(&priv->gpio))
+		return -EREMOTEIO;
+	ret = dm_gpio_get_value(&priv->gpio);
+	if (ret < 0)
+		return ret;
+
+	return ret ? LEDST_ON : LEDST_OFF;
+}
+
 static int led_gpio_probe(struct udevice *dev)
 {
 	struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
@@ -95,6 +109,7 @@ static int led_gpio_bind(struct udevice *parent)
 
 static const struct led_ops gpio_led_ops = {
 	.set_state	= gpio_led_set_state,
+	.get_state	= gpio_led_get_state,
 };
 
 static const struct udevice_id led_gpio_ids[] = {
diff --git a/include/led.h b/include/led.h
index 8af87ea8ea..bbab4d14c9 100644
--- a/include/led.h
+++ b/include/led.h
@@ -33,6 +33,14 @@ struct led_ops {
 	 * @return 0 if OK, -ve on error
 	 */
 	int (*set_state)(struct udevice *dev, enum led_state_t state);
+
+	/**
+	 * led_get_state() - get the state of an LED
+	 *
+	 * @dev:	LED device to change
+	 * @return LED state led_state_t, or -ve on error
+	 */
+	enum led_state_t (*get_state)(struct udevice *dev);
 };
 
 #define led_get_ops(dev)	((struct led_ops *)(dev)->driver->ops)
@@ -55,4 +63,12 @@ int led_get_by_label(const char *label, struct udevice **devp);
  */
 int led_set_state(struct udevice *dev, enum led_state_t state);
 
+/**
+ * led_get_state() - get the state of an LED
+ *
+ * @dev:	LED device to change
+ * @return LED state led_state_t, or -ve on error
+ */
+enum led_state_t led_get_state(struct udevice *dev);
+
 #endif
diff --git a/test/dm/led.c b/test/dm/led.c
index ebb9b46584..68aa39bd4d 100644
--- a/test/dm/led.c
+++ b/test/dm/led.c
@@ -43,9 +43,11 @@ static int dm_test_led_gpio(struct unit_test_state *uts)
 	ut_asserteq(0, sandbox_gpio_get_value(gpio, offset));
 	ut_assertok(led_set_state(dev, LEDST_ON));
 	ut_asserteq(1, sandbox_gpio_get_value(gpio, offset));
+	ut_asserteq(LEDST_ON, led_get_state(dev));
 
 	ut_assertok(led_set_state(dev, LEDST_OFF));
 	ut_asserteq(0, sandbox_gpio_get_value(gpio, offset));
+	ut_asserteq(LEDST_OFF, led_get_state(dev));
 
 	return 0;
 }
-- 
2.12.2.564.g063fe858b8-goog