spring: battery LED breath yellow on battery assist

When in battery assit mode, show breathing yellow on battery LED slowly
to indicate battery is actually discharging.

BUG=chrome-os-partner:17561
TEST=Manual
BRANCH=none

Change-Id: I688470d8870b181bf2dd20b5ebcbd6e2d861c5b0
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/44514
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

3 files changed, 133 insertions, 9 deletions

diff --git a/board/spring/board.c b/board/spring/board.c
index da74c966ee..d7e7224bd2 100644
--- a/board/spring/board.c
+++ b/board/spring/board.c
@@ -31,10 +31,20 @@
 #define HARD_RESET_TIMEOUT_MS 5
 
 /* We use yellow LED instead of blue LED. Re-map colors here. */
+#define LED_COLOR_NONE   LP5562_COLOR_NONE
 #define LED_COLOR_GREEN  LP5562_COLOR_GREEN
 #define LED_COLOR_YELLOW LP5562_COLOR_BLUE
 #define LED_COLOR_RED    LP5562_COLOR_RED
 
+/* LED breathing program */
+uint8_t breathing_prog[] = {0x41, 0xff,  /* 0x80 -> 0x0 */
+			    0x41, 0x7f,  /* 0x0 -> 0x80 */
+			    0x7f, 0x00,  /* Wait ~4s */
+			    0x7f, 0x00,
+			    0x7f, 0x00,
+			    0x7f, 0x00,
+			    0x00, 0x00}; /* Repeat */
+
 /* GPIO interrupt handlers prototypes */
 #ifndef CONFIG_TASK_GAIAPOWER
 #define gaia_power_event NULL
@@ -299,11 +309,38 @@ int board_get_ac(void)
 	       adc_read_channel(ADC_CH_USB_VBUS_SNS) >= 4300;
 }
 
+int board_led_breathing(int enabled)
+{
+	int ret = 0;
+
+	if (!enabled) {
+		return lp5562_engine_control(LP5562_ENG_HOLD,
+					     LP5562_ENG_HOLD,
+					     LP5562_ENG_HOLD);
+	}
+
+	ret |= lp5562_engine_load(LP5562_ENG_SEL_1,
+				  breathing_prog,
+				  sizeof(breathing_prog));
+	ret |= lp5562_set_engine(LP5562_ENG_SEL_NONE,
+				 LP5562_ENG_SEL_NONE,
+				 LP5562_ENG_SEL_1);
+	ret |= lp5562_engine_control(LP5562_ENG_RUN,
+				     LP5562_ENG_HOLD,
+				     LP5562_ENG_HOLD);
+
+	return ret;
+}
+
 int board_battery_led(enum charging_state state)
 {
 	int current;
 	int desired_current;
-	uint32_t color = LED_COLOR_RED;
+	static uint32_t color = LED_COLOR_RED;
+	static int breathing;
+	int new_color = LED_COLOR_RED;
+	int new_breathing = 0;
+	int ret = 0;
 
 	/*
 	 * LED power is controlled by accessory detection. We only
@@ -311,30 +348,47 @@ int board_battery_led(enum charging_state state)
 	 */
 	switch (state) {
 	case ST_IDLE:
-		color = LED_COLOR_GREEN;
+		new_color = LED_COLOR_GREEN;
+		break;
+	case ST_DISCHARGING:
+		new_color = LED_COLOR_NONE;
 		break;
-	case ST_DISCHARGING: /* Battery assist */
 	case ST_PRE_CHARGING:
-		color = LED_COLOR_YELLOW;
+		new_color = LED_COLOR_YELLOW;
 		break;
 	case ST_CHARGING:
 		if (battery_current(&current) ||
 		    battery_desired_current(&desired_current)) {
 			/* Cannot talk to the battery. Set LED to red. */
-			color = LED_COLOR_RED;
+			new_color = LED_COLOR_RED;
+			break;
+		}
+
+		if (current < 0 && desired_current > 0) { /* Battery assist */
+			new_breathing = 1;
+			new_color = LED_COLOR_NONE;
 			break;
 		}
+
 		if (current && desired_current)
-			color = LED_COLOR_YELLOW;
+			new_color = LED_COLOR_YELLOW;
 		else
-			color = LED_COLOR_GREEN;
+			new_color = LED_COLOR_GREEN;
 		break;
 	case ST_CHARGING_ERROR:
-		color = LED_COLOR_RED;
+		new_color = LED_COLOR_RED;
 		break;
 	}
 
-	return lp5562_set_color(color);
+	if (new_breathing != breathing) {
+		ret |= board_led_breathing(new_breathing);
+		breathing = new_breathing;
+	}
+	if (new_color != color) {
+		ret |= lp5562_set_color(new_color);
+		color = new_color;
+	}
+	return ret;
 }
 
 /*****************************************************************************/
diff --git a/common/lp5562.c b/common/lp5562.c
index a4c0e85fd6..09ee0df2c5 100644
--- a/common/lp5562.c
+++ b/common/lp5562.c
@@ -21,6 +21,11 @@ inline int lp5562_write(uint8_t reg, uint8_t val)
 	return i2c_write8(I2C_PORT_HOST, LP5562_I2C_ADDR, reg, val);
 }
 
+inline int lp5562_read(uint8_t reg, int *val)
+{
+	return i2c_read8(I2C_PORT_HOST, LP5562_I2C_ADDR, reg, val);
+}
+
 int lp5562_set_color(uint32_t rgb)
 {
 	int ret = 0;
@@ -32,6 +37,51 @@ int lp5562_set_color(uint32_t rgb)
 	return ret;
 }
 
+int lp5562_set_engine(uint8_t r, uint8_t g, uint8_t b)
+{
+	return lp5562_write(LP5562_REG_LED_MAP, (r << 4) | (g << 2) | b);
+}
+
+int lp5562_engine_load(int engine, uint8_t *program, int size)
+{
+	int prog_addr = LP5562_REG_ENG_PROG(engine);
+	int i, ret, val;
+	int shift = 6 - engine * 2;
+
+	ret = lp5562_read(LP5562_REG_OP_MODE, &val);
+	if (ret)
+		return ret;
+	val &= ~(0x3 << shift);
+	val |= 0x1 << shift;
+	ret = lp5562_write(LP5562_REG_OP_MODE, val);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < size; ++i) {
+		ret = lp5562_write(prog_addr + i, program[i]);
+		if (ret)
+			return ret;
+	}
+
+	val &= ~(0x3 << shift);
+	val |= 0x2 << shift;
+	ret = lp5562_write(LP5562_REG_OP_MODE, val);
+
+	return ret;
+}
+
+int lp5562_engine_control(int eng1, int eng2, int eng3)
+{
+	int ret, val;
+
+	ret = lp5562_read(LP5562_REG_ENABLE, &val);
+	if (ret)
+		return ret;
+	val &= 0xc0;
+	val |= (eng1 << 4) | (eng2 << 2) | eng3;
+	return lp5562_write(LP5562_REG_ENABLE, val);
+}
+
 int lp5562_poweron(void)
 {
 	int ret = 0;
diff --git a/include/lp5562.h b/include/lp5562.h
index 8bb8d71188..b993825c7a 100644
--- a/include/lp5562.h
+++ b/include/lp5562.h
@@ -26,10 +26,21 @@
 #define LP5562_REG_W_CURRENT	0x0f
 #define LP5562_REG_LED_MAP	0x70
 
+#define LP5562_REG_ENG_PROG(n)	(0x10 + ((n)-1) * 0x20)
+
+#define LP5562_COLOR_NONE	0x000000
 #define LP5562_COLOR_RED	0x800000
 #define LP5562_COLOR_GREEN	0x008000
 #define LP5562_COLOR_BLUE	0x000080
 
+#define LP5562_ENG_SEL_NONE	0x0
+#define LP5562_ENG_SEL_1	0x1
+#define LP5562_ENG_SEL_2	0x2
+#define LP5562_ENG_SEL_3	0x3
+
+#define LP5562_ENG_HOLD		0x0
+#define LP5562_ENG_RUN		0x2
+
 /* Power on and initialize LP5562. */
 int lp5562_poweron(void);
 
@@ -42,4 +53,13 @@ int lp5562_poweroff(void);
  */
 int lp5562_set_color(uint32_t rgb);
 
+/* Set lighting engine used by each color */
+int lp5562_set_engine(uint8_t r, uint8_t g, uint8_t b);
+
+/* Load lighting engine program */
+int lp5562_engine_load(int engine, uint8_t *program, int size);
+
+/* Control lighting engine execution state */
+int lp5562_engine_control(int eng1, int eng2, int eng3);
+
 #endif /* LP5562_H */