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 <ansuelsmth@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig
index bee74b257513be41b05f75215d797b3b9046bea7..59b007a7ef5108a1d4845ef11a0a887c378e93ed 100644 (file)
--- a/drivers/led/Kconfig
+++ b/drivers/led/Kconfig
@@ -9,6 +9,17 @@ config LED
          can provide access to board-specific LEDs. Use of the device tree
          for configuration is encouraged.
 
+config LED_BOOT
+       bool "Enable LED boot support"
+       help
+         Enable LED boot support.
+
+         LED boot is a specific LED assigned to signal boot operation status.
+         Defined in Device Tree /options/u-boot node. Refer here for the supported
+         options [1].
+
+         [1] dtschema/schemas/options/u-boot.yaml
+
 config LED_BCM6328
        bool "LED Support for BCM6328"
        depends on LED && ARCH_BMIPS

diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c
index 199d68bc25a83f21544d40fd00cd874efebdfd78..54113213dcfd9253ca17abedd14c1bb8a0d2f69e 100644 (file)
--- a/drivers/led/led-uclass.c
+++ b/drivers/led/led-uclass.c
@@ -94,6 +94,75 @@ int led_set_period(struct udevice *dev, int period_ms)
        return -ENOSYS;
 }
 
+#ifdef CONFIG_LED_BOOT
+static int led_boot_get(struct udevice **devp, int *period_ms)
+{
+       struct led_uc_priv *priv;
+       struct uclass *uc;
+       int ret;
+
+       ret = uclass_get(UCLASS_LED, &uc);
+       if (ret)
+               return ret;
+
+       priv = uclass_get_priv(uc);
+       if (!priv->boot_led_label)
+               return -ENOENT;
+
+       if (period_ms)
+               *period_ms = priv->boot_led_period;
+
+       return led_get_by_label(priv->boot_led_label, devp);
+}
+
+int led_boot_on(void)
+{
+       struct udevice *dev;
+       int ret;
+
+       ret = led_boot_get(&dev, NULL);
+       if (ret)
+               return ret;
+
+       return led_set_state(dev, LEDST_ON);
+}
+
+int led_boot_off(void)
+{
+       struct udevice *dev;
+       int ret;
+
+       ret = led_boot_get(&dev, NULL);
+       if (ret)
+               return ret;
+
+       return led_set_state(dev, LEDST_OFF);
+}
+
+#if defined(CONFIG_LED_BLINK) || defined(CONFIG_LED_SW_BLINK)
+int led_boot_blink(void)
+{
+       struct udevice *dev;
+       int period_ms, ret;
+
+       ret = led_boot_get(&dev, &period_ms);
+       if (ret)
+               return ret;
+
+       ret = led_set_period(dev, period_ms);
+       if (ret) {
+               if (ret != -ENOSYS)
+                       return ret;
+
+               /* fallback to ON with no set_period and no SW_BLINK */
+               return led_set_state(dev, LEDST_ON);
+       }
+
+       return led_set_state(dev, LEDST_BLINK);
+}
+#endif
+#endif
+
 static int led_post_bind(struct udevice *dev)
 {
        struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
@@ -158,10 +227,26 @@ static int led_post_probe(struct udevice *dev)
        return ret;
 }
 
+#ifdef CONFIG_LED_BOOT
+static int led_init(struct uclass *uc)
+{
+       struct led_uc_priv *priv = uclass_get_priv(uc);
+
+       priv->boot_led_label = ofnode_options_read_str("boot-led");
+       priv->boot_led_period = ofnode_options_read_int("boot-led-period", 250);
+
+       return 0;
+}
+#endif
+
 UCLASS_DRIVER(led) = {
        .id             = UCLASS_LED,
        .name           = "led",
        .per_device_plat_auto   = sizeof(struct led_uc_plat),
        .post_bind      = led_post_bind,
        .post_probe     = led_post_probe,
+#ifdef CONFIG_LED_BOOT
+       .init           = led_init,
+       .priv_auto      = sizeof(struct led_uc_priv),
+#endif
 };

diff --git a/include/led.h b/include/led.h
index 99f93c5ef86d5afc22dedd975251260d307a5593..49ec2998a33bd36f5b4e416bf35c6f12869844bd 100644 (file)
--- 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