fwk: dogwood: LED2 should blinking if the 12V is not connected

We missed following up on the UI ERS x6 to change the LED2 behavior.
EC should blink the LED2 during startup the system if 12V is not connected.

BRANCH=fwk-dogwood-27111
BUG=https://app.clickup.com/t/86ettgaw5
TEST=check the LED2 is blinking if 12V is not connected during startup the system
     and turn off the LED2 after turning off the PSU and shutdown to G3.

Signed-off-by: Josh Tsai <Josh_Tsai@compal.com>

Author: Josh-Tsai

zephyr/program/framework/dogwood/src/power_sequence.c

@@ -382,6 +382,17 @@ bool power_5vsb_exit(void)
 	return true;
 }
 
+void power_led2_blinking(void);
+DECLARE_DEFERRED(power_led2_blinking);
+void power_led2_blinking(void)
+{
+	static int tick;
+
+	/* blink LED2 with 2 Hz */
+	gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_led2_drv), !!(tick++ % 2));
+	hook_call_deferred(&power_led2_blinking_data, 500 * MSEC);
+}
+
 static void power_check_12vb_apu(void)
 {
 	int voltage = ina2xx_get_voltage(0); /* Unit: mV */
@@ -391,10 +402,19 @@ static void power_check_12vb_apu(void)
 	 * EC read the ina236 bus voltage register to monitor the
 	 * 12VB_APU is present or not to control the debug led2.
 	 */
-	if (voltage < 5000 || psu_is_off) {
-		set_diagnostic(DIAGNOSTICS_12V_OK, 1);
-		gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_led2_drv), 0);
+	if (voltage < 5000) {
+
+		if (psu_is_off) {
+			/* Strat blinking the LED2 (G3) */
+			hook_call_deferred(&power_led2_blinking_data, -1);
+			gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_led2_drv), 0);
+		} else {
+			/* Strat blinking the LED2 (S0 but 12V is not detected) */
+			power_led2_blinking();
+			set_diagnostic(DIAGNOSTICS_12V_OK, 1);
+		}
 	} else
+		/* Turn on the LED2 (S0 and 12V is detected) */
 		gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_led2_drv), 1);
 }