led: implement LED boot API

Implement LED boot API to signal correct boot of the system.

led_boot_on/off/blink() are introduced to turn ON, OFF and BLINK the
designated boot LED.

New Kconfig is introduced, CONFIG_LED_BOOT to enable the feature.
This makes use of the /options/u-boot property "boot-led" to the
define the boot LED.
It's also introduced a new /options/u-boot property "boot-led-period"
to define the default period when the LED is set to blink mode.

If "boot-led-period" is not defined, the value of 250 (ms) is
used by default.

If CONFIG_LED_BLINK or CONFIG_LED_SW_BLINK is not enabled,
led_boot_blink call will fallback to simple LED ON.

To cache the data we repurpose the now unused led_uc_priv for storage of
global LED uclass info.

Signed-off-by: Christian Marangi <[email protected]>
Reviewed-by: Simon Glass <[email protected]>

1 files changed, 53 insertions, 2 deletions

diff --git a/include/led.h b/include/led.h
index 99f93c5ef86..49ec2998a33 100644
--- a/include/led.h
+++ b/include/led.h
@@ -9,6 +9,7 @@
 
 #include <stdbool.h>
 #include <cyclic.h>
+#include <dm/ofnode.h>
 
 struct udevice;
 
@@ -52,10 +53,15 @@ struct led_uc_plat {
 /**
  * struct led_uc_priv - Private data the uclass stores about each device
  *
- * @period_ms:	Flash period in milliseconds
+ * @boot_led_label:	Boot LED label
+ * @boot_led_dev:	Boot LED dev
+ * @boot_led_period:	Boot LED blink period
  */
 struct led_uc_priv {
-	int period_ms;
+#ifdef CONFIG_LED_BOOT
+	const char *boot_led_label;
+	int boot_led_period;
+#endif
 };
 
 struct led_ops {
@@ -141,4 +147,49 @@ int led_sw_set_period(struct udevice *dev, int period_ms);
 bool led_sw_is_blinking(struct udevice *dev);
 bool led_sw_on_state_change(struct udevice *dev, enum led_state_t state);
 
+#ifdef CONFIG_LED_BOOT
+
+/**
+ * led_boot_on() - turn ON the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int led_boot_on(void);
+
+/**
+ * led_boot_off() - turn OFF the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int led_boot_off(void);
+
+#if defined(CONFIG_LED_BLINK) || defined(CONFIG_LED_SW_BLINK)
+/**
+ * led_boot_blink() - turn ON the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int led_boot_blink(void);
+
+#else
+/* If LED BLINK is not supported/enabled, fallback to LED ON */
+#define led_boot_blink led_boot_on
+#endif
+#else
+static inline int led_boot_on(void)
+{
+	return -ENOSYS;
+}
+
+static inline int led_boot_off(void)
+{
+	return -ENOSYS;
+}
+
+static inline int led_boot_blink(void)
+{
+	return -ENOSYS;
+}
+#endif
+
 #endif