BACKPORT: common: Add lightbar dimming based on outside light.

Unless the lid is closed, the ALS is used for lightbar dimming.
Change the google colors depending on the light sensor result.

BUG=chrome-os-partner:44400, b:27849483, b:36973851
BRANCH=smaug, cyan, ultima
TEST=Check all 3 levels of brightness of the lightbar.
Check value using "adb shell ectool lightbar"
Check double tap color are not affected and is using full brightness.

Reviewed-on: https://chromium-review.googlesource.com/301216
Reviewed-by: Alec Berg <alecaberg@chromium.org>
(cherry picked from commit 7340e804a1e3ffba2f1ffb9bf826a33b8b5fb19c)
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/359391
Reviewed-on: https://chromium-review.googlesource.com/409478
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
(cherry picked from commit 4b09db60502503a7c7d823c56e512129ea114175)
Change-Id: I7b5e2890c3557f1dd3ae719f5f82ffb5fe7b24fb
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/489751

4 files changed, 60 insertions, 0 deletions

diff --git a/common/lightbar.c b/common/lightbar.c
index 879da25531..3a1e005c9e 100644
--- a/common/lightbar.c
+++ b/common/lightbar.c
@@ -18,6 +18,8 @@
 #include "host_command.h"
 #include "lb_common.h"
 #include "lightbar.h"
+#include "lid_switch.h"
+#include "motion_sense.h"
 #include "pwm.h"
 #include "system.h"
 #include "task.h"
@@ -192,6 +194,9 @@ static void lightbar_restore_state(void)
 #ifdef CONFIG_PWM_KBLIGHT
 static int last_backlight_level;
 #endif
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+static int last_google_color = -1;
+#endif
 
 static int demo_mode = DEMO_MODE_DEFAULT;
 
@@ -204,11 +209,30 @@ static int quantize_battery_level(int pct)
 	return bl;
 }
 
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+static int lux_level_to_google_color(int lux)
+{
+	int i;
+
+	if (!lid_is_open())
+		/* The lid shades the light sensor, use full brightness. */
+		return 0;
+
+	for (i = 0; i < lb_brightness_levels_count ; i++)
+		if (lux >= lb_brightness_levels[i].lux)
+			break;
+	return i;
+}
+#endif
+
 /* Update the known state. */
 static void get_battery_level(void)
 {
 	int pct = 0;
 	int bl;
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+	int color_id;
+#endif
 
 	if (demo_mode)
 		return;
@@ -255,6 +279,17 @@ static void get_battery_level(void)
 		lb_set_brightness(pct);
 	}
 #endif
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+	/* Read last value (in lux) collected by the motion sensor. */
+	/* Convert lux into brightness percentage */
+	color_id = lux_level_to_google_color(MOTION_SENSE_LUX);
+
+	if (color_id != last_google_color) {
+		last_google_color = pct;
+		memcpy(st.p.color, lb_brightness_levels[color_id].color,
+		       sizeof(lb_brightness_levels[color_id].color));
+	}
+#endif
 }
 
 /* Forcing functions for demo mode, called by the keyboard task. */
diff --git a/include/config.h b/include/config.h
index 13d902a565..0af953bd68 100644
--- a/include/config.h
+++ b/include/config.h
@@ -97,6 +97,9 @@
 #undef CONFIG_ALS_ISL29035
 #undef CONFIG_ALS_OPT3001
 
+/* Define which ALS sensor is used for dimming the lightbar when dark */
+#undef CONFIG_ALS_LIGHTBAR_DIMMING
+
 /* Support AP hang detection host command and state machine */
 #undef CONFIG_AP_HANG_DETECT
 
diff --git a/include/lightbar.h b/include/lightbar.h
index 293eeb2ab2..8648e3f3bd 100644
--- a/include/lightbar.h
+++ b/include/lightbar.h
@@ -34,6 +34,24 @@ enum lb_control {
 	LB_CONT_MAX
 };
 
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+/*
+ * For dimming the lightbar in the dark, we define an array to
+ * describe the expected colors:
+ * if luminosity is more than 'lux', the color defined will be used.
+ * The last entry must have lux == 0.
+ * Defining brightness is not enough to prevent washed color in low
+ * lux setting.
+ */
+struct lb_brightness_def {
+	uint16_t lux;
+	struct rgb_s color[4];
+};
+
+extern struct lb_brightness_def lb_brightness_levels[];
+extern const unsigned lb_brightness_levels_count;
+#endif
+
 /* Request a preset sequence from the lightbar task. */
 void lightbar_sequence_f(enum lightbar_sequence num, const char *f);
 #define lightbar_sequence(A) lightbar_sequence_f(A, __func__)
diff --git a/include/motion_sense.h b/include/motion_sense.h
index 86d3e87ab8..ed24f232fd 100644
--- a/include/motion_sense.h
+++ b/include/motion_sense.h
@@ -185,4 +185,8 @@ void motion_sense_fifo_add_unit(struct ec_response_motion_sensor_data *data,
 #else
 #define ALL_MOTION_SENSORS motion_sensor_count
 #endif
+
+#ifdef CONFIG_ALS_LIGHTBAR_DIMMING
+#define MOTION_SENSE_LUX motion_sensors[CONFIG_ALS_LIGHTBAR_DIMMING].raw_xyz[0]
+#endif
 #endif /* __CROS_EC_MOTION_SENSE_H */