[PATCH v5 03/11] led: implement LED boot API

Christian Marangi
2024-10-01T13:20:30Z

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>
---
drivers/led/Kconfig | 11 ++++++
drivers/led/led-uclass.c | 85 ++++++++++++++++++++++++++++++++++++++++
include/led.h | 55 +++++++++++++++++++++++++-
3 files changed, 149 insertions(+), 2 deletions(-)

diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig
index bee74b25751..59b007a7ef5 100644
--- 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 199d68bc25a..54113213dcf 100644
--- 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 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
--
2.45.2