manta: add liblights for backlight
Adds an initial liblights implementation that only supports the
backlight.
Change-Id: I6995602249922f88ac129ac6a02039982ab6de85
diff --git a/liblights/lights.c b/liblights/lights.c
new file mode 100644
index 0000000..67013f9
--- /dev/null
+++ b/liblights/lights.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2012 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_TAG "lights"
+#include <cutils/log.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <hardware/lights.h>
+
+static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
+
+char const *const LCD_FILE = "/sys/class/backlight/pwm-backlight.0/brightness";
+
+static int write_int(char const *path, int value)
+{
+ int fd;
+ static int already_warned;
+
+ ALOGV("write_int: path %s, value %d", path, value);
+ 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 rgb_to_brightness(struct light_state_t const *state)
+{
+ /* use max of the RGB components for brightness */
+ int color = state->color & 0x00ffffff;
+ int red = (color >> 16) & 0x000000ff;
+ int green = (color >> 8) & 0x000000ff;
+ int blue = color & 0x000000ff;
+
+ int brightness = red;
+ if (green > brightness)
+ brightness = green;
+ if (blue > brightness)
+ brightness = blue;
+
+ return brightness;
+}
+
+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 close_lights(struct hw_device_t *dev)
+{
+ ALOGV("close_light is called");
+ free(dev);
+
+ return 0;
+}
+
+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 (strcmp(LIGHT_ID_BACKLIGHT, name) == 0)
+ set_light = set_light_backlight;
+ else
+ return -EINVAL;
+
+ struct light_device_t *dev = malloc(sizeof(struct light_device_t));
+ if (!dev)
+ return -ENOMEM;
+ 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 = 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,
+};
+
+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,
+};