[PATCH 3/9] led: implement LED boot API

[Christian Marangi]

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 are introduced, CONFIG_LED_BOOT_ENABLE to enable the feature,
CONFIG_LED_BOOT_LABEL to declare the LED label in DT to reference
the LED for BOOT usage and CONFIG_LED_BOOT_PERIOD to declare the
blinking period.

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

Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>
---
 drivers/led/Kconfig | 22 ++++++++++++++++++++++
 include/led.h       | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig
index 13d6eb40cea..0506a33b6ee 100644
--- a/drivers/led/Kconfig
+++ b/drivers/led/Kconfig
@@ -9,6 +9,28 @@ config LED
 	  can provide access to board-specific LEDs. Use of the device tree
 	  for configuration is encouraged.
 
+config LED_BOOT_ENABLE
+	bool "Enable LED boot support"
+	help
+	  Enable LED boot support.
+
+	  LED boot is a specific LED assigned to signal boot operation status.
+
+config LED_BOOT_LABEL
+	string "LED boot label"
+	depends on LED_BOOT_ENABLE
+	help
+	  LED label defined in DT to assign for LED boot usage.
+
+config LED_BOOT_PERIOD
+	int "LED boot period"
+	depends on LED_BOOT_ENABLE && LED_BLINK
+	default 2
+	help
+	  LED boot blink period in ms.
+
+	  Value is normalized per CONFIG_SYS_HZ.
+
 config LED_BCM6328
 	bool "LED Support for BCM6328"
 	depends on LED && ARCH_BMIPS
diff --git a/include/led.h b/include/led.h
index 71dd7a28d93..479c6d17c5b 100644
--- a/include/led.h
+++ b/include/led.h
@@ -136,4 +136,44 @@ int led_set_period_by_label(const char *label, int period_ms);
  */
 int led_bind_generic(struct udevice *parent, const char *driver_name);
 
+#ifdef CONFIG_LED_BOOT_ENABLE
+
+#define LED_BOOT_PERIOD CONFIG_SYS_HZ / CONFIG_LED_BOOT_PERIOD
+
+/**
+ * led_boot_on() - turn ON the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static inline int led_boot_on(void)
+{
+	return led_set_state_by_label(CONFIG_LED_BOOT_LABEL, LEDST_ON);
+}
+
+/**
+ * led_boot_off() - turn OFF the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static inline int led_boot_off(void)
+{
+	return led_set_state_by_label(CONFIG_LED_BOOT_LABEL, LEDST_OFF);
+}
+
+#ifdef CONFIG_LED_BLINK
+/**
+ * led_boot_blink() - turn ON the designated LED for booting
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static inline int led_boot_blink(void)
+{
+	return led_set_period_by_label(CONFIG_LED_BOOT_LABEL, LED_BOOT_PERIOD);
+}
+#else
+/* If LED BLINK is not supported/enabled, fallback to LED ON */
+#define led_boot_blink led_boot_on
+#endif
+#endif
+
 #endif
-- 
2.45.1