healthd: charger: Add tricolor led to indicate battery capacity

Add led to indicate battery capacity when doing off mode charging. The
led behavior is design as below:
   i. 	Shows red led if capacity is lower than 15%.
   ii.	Shows yellow (red + green) led if capacity is
	lower than 90% but higher than 15%.
   iii. Shows green led if capacity is higher than 90%.

Change-Id: If637defec8a04e859b00a6492ec1f95d6bff2200

1 files changed, 87 insertions, 0 deletions

diff --git a/healthd/healthd_mode_charger.cpp b/healthd/healthd_mode_charger.cpp
index c0db457..e4e1632 100644
--- a/healthd/healthd_mode_charger.cpp
+++ b/healthd/healthd_mode_charger.cpp
@@ -72,6 +72,9 @@ char *locale;
 #define LAST_KMSG_PATH          "/proc/last_kmsg"
 #define LAST_KMSG_PSTORE_PATH   "/sys/fs/pstore/console-ramoops"
 #define LAST_KMSG_MAX_SZ        (32 * 1024)
+#define RED_LED_PATH            "/sys/class/leds/red/brightness"
+#define GREEN_LED_PATH          "/sys/class/leds/green/brightness"
+#define BLUE_LED_PATH           "/sys/class/leds/blue/brightness"
 
 #define LOGE(x...) do { KLOG_ERROR("charger", x); } while (0)
 #define LOGW(x...) do { KLOG_WARNING("charger", x); } while (0)
@@ -168,6 +171,33 @@ static struct animation battery_animation = {
     .capacity = 0,
 };
 
+enum {
+    RED_LED = 0x01 << 0,
+    GREEN_LED = 0x01 << 1,
+    BLUE_LED = 0x01 << 2,
+};
+
+struct led_ctl {
+    int color;
+    const char *path;
+};
+
+struct led_ctl leds[3] =
+    {{RED_LED, RED_LED_PATH},
+    {GREEN_LED, GREEN_LED_PATH},
+    {BLUE_LED, BLUE_LED_PATH}};
+
+struct soc_led_color_mapping {
+    int soc;
+    int color;
+};
+
+struct soc_led_color_mapping soc_leds[3] = {
+    {15, RED_LED},
+    {90, RED_LED | GREEN_LED},
+    {100, GREEN_LED},
+};
+
 static struct charger charger_state;
 static struct healthd_config *healthd_config;
 static struct android::BatteryProperties *batt_prop;
@@ -175,6 +205,54 @@ static int char_width;
 static int char_height;
 static bool minui_inited;
 
+static int set_tricolor_led(int on, int color)
+{
+    int fd, i;
+    char buffer[10];
+
+    for (i = 0; i < (int)ARRAY_SIZE(leds); i++) {
+        if ((color & leds[i].color) && (access(leds[i].path, R_OK | W_OK) == 0)) {
+            fd = open(leds[i].path, O_RDWR);
+            if (fd < 0) {
+                LOGE("Could not open red led node\n");
+                goto cleanup;
+            }
+            if (on)
+                snprintf(buffer, sizeof(int), "%d\n", 255);
+            else
+                snprintf(buffer, sizeof(int), "%d\n", 0);
+
+            if (write(fd, buffer, strlen(buffer)) < 0)
+                LOGE("Could not write to led node\n");
+cleanup:
+            if (fd >= 0)
+                close(fd);
+        }
+    }
+
+    return 0;
+}
+
+static int set_battery_soc_leds(int soc)
+{
+    int i, color;
+    static int old_color = 0;
+
+    for (i = 0; i < (int)ARRAY_SIZE(soc_leds); i++) {
+        if (soc < soc_leds[i].soc)
+            break;
+    }
+    color = soc_leds[i].color;
+    if (old_color != color) {
+        set_tricolor_led(0, old_color);
+        set_tricolor_led(1, color);
+        old_color = color;
+        LOGV("soc = %d, set led color 0x%x\n", soc, soc_leds[i].color);
+    }
+
+    return 0;
+}
+
 /* current time in milliseconds */
 static int64_t curr_time_ms(void)
 {
@@ -576,11 +654,20 @@ static void handle_input_state(struct charger *charger, int64_t now)
 
 static void handle_power_supply_state(struct charger *charger, int64_t now)
 {
+    static int old_soc = 0;
+    int soc;
+
     if (!charger->have_battery_state)
         return;
 
     healthd_board_mode_charger_battery_update(batt_prop);
 
+    soc = get_battery_capacity();
+    if (old_soc != soc) {
+        old_soc = soc;
+        set_battery_soc_leds(soc);
+    }
+
     if (!charger->charger_connected) {
 
         /* Last cycle would have stopped at the extreme top of battery-icon