rambi: Set LED colors based on battery and chipset state

Picked some reasonable values.  Subject to later tweaking.

BUG=chrome-os-partner:23634
BRANCH=none
TEST=On AC power, charging = yellow
     On AC power, done charging = green
     No battery = blinking red
     On battery, AP on = dim green
     On battery, AP off = off

Change-Id: I2eb901ea4de98fec8cd83e403d6ed8a06a2a9ca9
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/174778
Reviewed-by: Dave Parker <dparker@chromium.org>

1 files changed, 110 insertions, 4 deletions

diff --git a/board/rambi/led.c b/board/rambi/led.c
index 451aae2bc3..2de4584411 100644
--- a/board/rambi/led.c
+++ b/board/rambi/led.c
@@ -5,15 +5,48 @@
  * Battery LED control for Rambi
  */
 
+#include "charge_state.h"
+#include "chipset.h"
 #include "gpio.h"
 #include "hooks.h"
 #include "led_common.h"
 #include "pwm.h"
 #include "util.h"
 
-const enum ec_led_id supported_led_ids[] = {EC_LED_ID_BATTERY_LED};
+const enum ec_led_id supported_led_ids[] = {EC_LED_ID_POWER_LED};
 const int supported_led_ids_count = ARRAY_SIZE(supported_led_ids);
 
+enum led_color {
+	LED_OFF = 0,
+	LED_RED,
+	LED_YELLOW,
+	LED_GREEN,
+	LED_DIM_GREEN,
+
+	/* Number of colors, not a color itself */
+	LED_COLOR_COUNT
+};
+
+/* Brightness vs. color, for {red, green} LEDs */
+static const uint8_t color_brightness[LED_COLOR_COUNT][2] = {
+	{0, 0},
+	{100, 0},
+	{40, 80},
+	{0, 100},
+	{0, 10},
+};
+
+/**
+ * Set LED color
+ *
+ * @param color		Enumerated color value
+ */
+static void set_color(enum led_color color)
+{
+	pwm_set_duty(PWM_CH_LED_RED, color_brightness[color][0]);
+	pwm_set_duty(PWM_CH_LED_GREEN, color_brightness[color][1]);
+}
+
 void led_get_brightness_range(enum ec_led_id led_id, uint8_t *brightness_range)
 {
 	brightness_range[EC_LED_COLOR_RED] = 100;
@@ -37,9 +70,82 @@ static void led_init(void)
 	 * seems to ground the pins instead of letting them float.
 	 */
 	pwm_enable(PWM_CH_LED_RED, 1);
-	pwm_set_duty(PWM_CH_LED_RED, 0);
-
 	pwm_enable(PWM_CH_LED_GREEN, 1);
-	pwm_set_duty(PWM_CH_LED_GREEN, 0);
+	set_color(LED_OFF);
 }
 DECLARE_HOOK(HOOK_INIT, led_init, HOOK_PRIO_DEFAULT);
+
+/**
+ * Called by hook task every 250 ms
+ */
+static void led_tick(void)
+{
+	static int suspended_prev;
+	static unsigned ticks;
+	int blink_on;
+
+	int suspended = chipset_in_state(CHIPSET_STATE_SUSPEND);
+	int chstate = charge_get_state();
+
+	/* If we don't control the LED, nothing to do */
+	if (!led_auto_control_is_enabled(EC_LED_ID_POWER_LED))
+		return;
+
+	/* If we're just suspending now, reset ticks so LED changes quickly */
+	if (suspended && !suspended_prev)
+		ticks = 0;
+	else
+		ticks++;
+
+	suspended_prev = suspended;
+
+	/* Blink with 25% duty cycle, 4 sec period */
+	blink_on = ticks % 16 < 4;
+
+	/* If charging error, blink red */
+	if (chstate == PWR_STATE_ERROR) {
+		set_color(blink_on ? LED_RED : LED_OFF);
+		return;
+	}
+
+	/* If charge-force-idle, blink green, 50% duty cycle, 2 sec period */
+	if (chstate == PWR_STATE_IDLE &&
+	    (charge_get_flags() & CHARGE_FLAG_FORCE_IDLE)) {
+		set_color((ticks & 0x4) ? LED_GREEN : LED_OFF);
+		return;
+	}
+
+	/*
+	 * If the system is charging, solid yellow.
+	 *
+	 * Note that this means you can't distinguish power states
+	 * (on/suspend/off) when the system is charging.
+	 */
+	if (chstate == PWR_STATE_CHARGE) {
+		set_color(LED_YELLOW);
+		return;
+	}
+
+	/* If suspended, blink yellow */
+	if (suspended) {
+		set_color(blink_on ? LED_YELLOW : LED_OFF);
+		return;
+	}
+
+	/* If AC connected and fully charged (or close to it), solid green */
+	if (chstate == PWR_STATE_CHARGE_NEAR_FULL ||
+	    chstate == PWR_STATE_IDLE) {
+		set_color(LED_GREEN);
+		return;
+	}
+
+	/* If powered on, dim green (just as an indicator we're on) */
+	if (chipset_in_state(CHIPSET_STATE_ON)) {
+		set_color(LED_DIM_GREEN);
+		return;
+	}
+
+	/* Otherwise, system is off and AC not connected, LED off */
+	set_color(LED_OFF);
+}
+DECLARE_HOOK(HOOK_TICK, led_tick, HOOK_PRIO_DEFAULT);