add light hal module
- initial version
- control lcd backlight
- control red, green, blue
Change-Id: Ibd24dcee3a739111f9eb6a7717b76754875da36e
diff --git a/liblight/lights.c b/liblight/lights.c
new file mode 100644
index 0000000..875d772
--- /dev/null
+++ b/liblight/lights.c
@@ -0,0 +1,301 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+// #define LOG_NDEBUG 0
+#define LOG_TAG "lights"
+
+#include <cutils/log.h>
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+#include <hardware/lights.h>
+
+/******************************************************************************/
+
+static pthread_once_t g_init = PTHREAD_ONCE_INIT;
+static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct light_state_t g_notification;
+static struct light_state_t g_battery;
+static int g_attention = 0;
+
+char const*const RED_LED_FILE
+ = "/sys/class/leds/red/brightness";
+
+char const*const GREEN_LED_FILE
+ = "/sys/class/leds/green/brightness";
+
+char const*const BLUE_LED_FILE
+ = "/sys/class/leds/blue/brightness";
+
+char const*const LCD_FILE
+ = "/sys/class/leds/lcd-backlight/brightness";
+
+/**
+ * device methods
+ */
+
+void init_globals(void)
+{
+ // init the mutex
+ pthread_mutex_init(&g_lock, NULL);
+}
+
+static int
+write_int(char const* path, int value)
+{
+ int fd;
+ static int already_warned = 0;
+
+ fd = open(path, O_RDWR);
+ if (fd >= 0) {
+ char buffer[20];
+ int bytes = sprintf(buffer, "%d\n", value);
+ int amt = write(fd, buffer, bytes);
+ close(fd);
+ return amt == -1 ? -errno : 0;
+ } else {
+ if (already_warned == 0) {
+ ALOGE("write_int failed to open %s\n", path);
+ already_warned = 1;
+ }
+ return -errno;
+ }
+}
+
+static int
+is_lit(struct light_state_t const* state)
+{
+ return state->color & 0x00ffffff;
+}
+
+static int
+rgb_to_brightness(struct light_state_t const* state)
+{
+ int color = state->color & 0x00ffffff;
+ return ((77*((color>>16)&0x00ff))
+ + (150*((color>>8)&0x00ff)) + (29*(color&0x00ff))) >> 8;
+}
+
+static int
+set_light_backlight(struct light_device_t* dev,
+ struct light_state_t const* state)
+{
+ int err = 0;
+ int brightness = rgb_to_brightness(state);
+ pthread_mutex_lock(&g_lock);
+ err = write_int(LCD_FILE, brightness);
+ pthread_mutex_unlock(&g_lock);
+ return err;
+}
+
+static int
+set_speaker_light_locked(struct light_device_t* dev,
+ struct light_state_t const* state)
+{
+ int len;
+ int alpha, red, green, blue;
+ int blink, freq, pwm;
+ int onMS, offMS;
+ unsigned int colorRGB;
+
+ switch (state->flashMode) {
+ case LIGHT_FLASH_TIMED:
+ onMS = state->flashOnMS;
+ offMS = state->flashOffMS;
+ break;
+ case LIGHT_FLASH_NONE:
+ default:
+ onMS = 0;
+ offMS = 0;
+ break;
+ }
+
+ colorRGB = state->color;
+
+#if 0
+ ALOGD("set_speaker_light_locked colorRGB=%08X, onMS=%d, offMS=%d\n",
+ colorRGB, onMS, offMS);
+#endif
+
+ red = (colorRGB >> 16) & 0xFF;
+ green = (colorRGB >> 8) & 0xFF;
+ blue = colorRGB & 0xFF;
+
+ // R, G, B value is among 0, 1, 2
+ if (red > 128) red = 2;
+ else if (red <= 128 && red > 0) red = 1;
+ if (green > 128) green = 2;
+ else if (green <= 128 && green > 0) green = 1;
+ if (blue > 128) blue = 2;
+ else if (blue <= 128 && blue > 0) red = 1;
+
+ write_int(RED_LED_FILE, red);
+ write_int(GREEN_LED_FILE, green);
+ write_int(BLUE_LED_FILE, blue);
+
+ // TODO
+ if (onMS > 0 && offMS > 0) {
+ int totalMS = onMS + offMS;
+
+ // the LED appears to blink about once per second if freq is 20
+ // 1000ms / 20 = 50
+ freq = totalMS / 50;
+ // pwm specifies the ratio of ON versus OFF
+ // pwm = 0 -> always off
+ // pwm = 255 => always on
+ pwm = (onMS * 255) / totalMS;
+
+ // the low 4 bits are ignored, so round up if necessary
+ if (pwm > 0 && pwm < 16)
+ pwm = 16;
+
+ blink = 1;
+ } else {
+ blink = 0;
+ freq = 0;
+ pwm = 0;
+ }
+
+ if (blink) {
+ write_int(RED_LED_FILE, freq);
+ }
+
+ return 0;
+}
+
+static void
+handle_speaker_battery_locked(struct light_device_t* dev)
+{
+ if (is_lit(&g_battery)) {
+ set_speaker_light_locked(dev, &g_battery);
+ } else {
+ set_speaker_light_locked(dev, &g_notification);
+ }
+}
+
+static int
+set_light_battery(struct light_device_t* dev,
+ struct light_state_t const* state)
+{
+ pthread_mutex_lock(&g_lock);
+ g_battery = *state;
+ handle_speaker_battery_locked(dev);
+ pthread_mutex_unlock(&g_lock);
+ return 0;
+}
+
+static int
+set_light_notifications(struct light_device_t* dev,
+ struct light_state_t const* state)
+{
+ pthread_mutex_lock(&g_lock);
+ g_notification = *state;
+ handle_speaker_battery_locked(dev);
+ pthread_mutex_unlock(&g_lock);
+ return 0;
+}
+
+static int
+set_light_attention(struct light_device_t* dev,
+ struct light_state_t const* state)
+{
+ pthread_mutex_lock(&g_lock);
+ if (state->flashMode == LIGHT_FLASH_HARDWARE) {
+ g_attention = state->flashOnMS;
+ } else if (state->flashMode == LIGHT_FLASH_NONE) {
+ g_attention = 0;
+ }
+ handle_speaker_battery_locked(dev);
+ pthread_mutex_unlock(&g_lock);
+ return 0;
+}
+
+
+/** Close the lights device */
+static int
+close_lights(struct light_device_t *dev)
+{
+ if (dev) {
+ free(dev);
+ }
+ return 0;
+}
+
+
+/******************************************************************************/
+
+/**
+ * module methods
+ */
+
+/** Open a new instance of a lights device using name */
+static int open_lights(const struct hw_module_t* module, char const* name,
+ struct hw_device_t** device)
+{
+ int (*set_light)(struct light_device_t* dev,
+ struct light_state_t const* state);
+
+ if (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
+ set_light = set_light_backlight;
+ else if (0 == strcmp(LIGHT_ID_BATTERY, name))
+ set_light = set_light_battery;
+ else if (0 == strcmp(LIGHT_ID_NOTIFICATIONS, name))
+ set_light = set_light_notifications;
+ else if (0 == strcmp(LIGHT_ID_ATTENTION, name))
+ set_light = set_light_attention;
+ else
+ return -EINVAL;
+
+ pthread_once(&g_init, init_globals);
+
+ struct light_device_t *dev = malloc(sizeof(struct light_device_t));
+ memset(dev, 0, sizeof(*dev));
+
+ dev->common.tag = HARDWARE_DEVICE_TAG;
+ dev->common.version = 0;
+ dev->common.module = (struct hw_module_t*)module;
+ dev->common.close = (int (*)(struct hw_device_t*))close_lights;
+ dev->set_light = set_light;
+
+ *device = (struct hw_device_t*)dev;
+ return 0;
+}
+
+static struct hw_module_methods_t lights_module_methods = {
+ .open = open_lights,
+};
+
+/*
+ * The lights Module
+ */
+struct hw_module_t HAL_MODULE_INFO_SYM = {
+ .tag = HARDWARE_MODULE_TAG,
+ .version_major = 1,
+ .version_minor = 0,
+ .id = LIGHTS_HARDWARE_MODULE_ID,
+ .name = "lights Module",
+ .author = "Google, Inc.",
+ .methods = &lights_module_methods,
+};