generic: First pass at adding lightsHAL for backlight

diff --git a/device.mk b/device.mk
index 5675608..fd1ae4e 100644
--- a/device.mk
+++ b/device.mk
@@ -65,7 +65,7 @@  PRODUCT_PROPERTY_OVERRIDES += \
     dalvik.vm.heapminfree=512k \
     dalvik.vm.heapmaxfree=$(CONFIG_DALVIK_VM_HEAPMAXFREE)m
 
-subdirs-true :=
+subdirs-true := lights
 subdirs-$(CONFIG_WIFI) += wifi
 subdirs-$(CONFIG_ETHERNET) += ethernet
 subdirs-$(CONFIG_SENSOR) += sensor
diff --git a/lights/Android.mk b/lights/Android.mk
new file mode 100644
index 0000000..dcea097
--- /dev/null
+++ b/lights/Android.mk
@@ -0,0 +1,33 @@ 
+# 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.
+
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+
+# HAL module implemenation, not prelinked and stored in
+# hw/<COPYPIX_HARDWARE_MODULE_ID>.<ro.board.platform>.so
+
+LOCAL_SRC_FILES := lights.c
+
+LOCAL_MODULE_RELATIVE_PATH := hw
+
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SHARED_LIBRARIES := liblog
+
+LOCAL_MODULE := lights.default
+
+include $(BUILD_SHARED_LIBRARY)
+
diff --git a/lights/device.mk b/lights/device.mk
new file mode 100644
index 0000000..406c668
--- /dev/null
+++ b/lights/device.mk
@@ -0,0 +1,4 @@ 
+PRODUCT_PACKAGES += lights.default
+PRODUCT_PACKAGES += lights.rc
+
+
diff --git a/lights/lights.c b/lights/lights.c
new file mode 100644
index 0000000..44c8f90
--- /dev/null
+++ b/lights/lights.c
@@ -0,0 +1,163 @@ 
+/*
+ * 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_TAG "lights"
+
+#include <cutils/log.h>
+
+#include <malloc.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+#include <hardware/lights.h>
+#include <hardware/hardware.h>
+
+static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
+char const* const BACKLIGHT_PATH_BASE = "/sys/class/backlight/";
+
+char backlight_path[1024];
+
+static int write_int(char const *path, int value)
+{
+	int fd;
+	static int already_warned = -1;
+	fd = open(path, O_RDWR);
+	if (fd >= 0) {
+		char buffer[20];
+		int bytes = snprintf(buffer, 20, "%d\n", value);
+		int amt = write(fd, buffer, bytes);
+		close(fd);
+		return amt == -1 ? -errno : 0;
+	} else {
+		if (already_warned == -1) {
+			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)
+{
+	int color = state->color & 0x00ffffff;
+	return ((77 * ((color >> 16) & 0x00ff))
+			+ (150 * ((color >> 8) & 0x00ff)) +
+			(29 * (color & 0x00ff))) >> 8;
+}
+
+static int set_light_notifications(struct light_device_t* dev,
+		struct light_state_t const* state)
+{
+	int err = 0;
+	return err;
+}
+
+static int set_light_backlight(struct light_device_t *dev,
+		struct light_state_t const *state)
+{
+	int err;
+	int brightness = rgb_to_brightness(state);
+
+	pthread_mutex_lock(&g_lock);
+	err = write_int(backlight_path, brightness);
+	pthread_mutex_unlock(&g_lock);
+
+	return err;
+}
+
+/** Close the lights device */
+static int close_lights(struct light_device_t *dev)
+{
+	if (dev)
+		free(dev);
+	return 0;
+}
+
+/** 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)
+{
+	struct light_device_t *dev = malloc(sizeof(struct light_device_t));
+	int (*set_light) (struct light_device_t *dev,
+			struct light_state_t const *state);
+	pthread_t lighting_poll_thread;
+	DIR *dir;
+	struct dirent *entry;
+
+	if (dev == NULL) {
+		ALOGE("failed to allocate memory");
+		return -1;
+	}
+	memset(dev, 0, sizeof(*dev));
+
+	if (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
+		set_light = set_light_backlight;
+	else
+		return -EINVAL;
+
+
+	if(!(dir = opendir(BACKLIGHT_PATH_BASE)))
+		return -EINVAL;
+	if (!(entry = readdir(dir)))
+		return -EINVAL;
+
+	do {
+		if (entry->d_type == DT_DIR) {
+			continue;
+		}
+		sprintf(backlight_path, "%s%s/brightness", BACKLIGHT_PATH_BASE, entry->d_name);
+	} while (entry = readdir(dir));
+	closedir(dir);
+
+
+	pthread_mutex_init(&g_lock, NULL);
+
+	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_methods =
+{
+	.open =  open_lights,
+};
+
+/*
+ * The backlight 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 = "Flo/mainline lights module",
+	.author = "NVIDIA,Linaro",
+	.methods = &lights_methods,
+};
diff --git a/ueventd.rc b/ueventd.rc
index ea76741..c56b776 100644
--- a/ueventd.rc
+++ b/ueventd.rc
@@ -13,6 +13,7 @@ 
 /sys/bus/iio/devices/iio:device* scan_elements/in_anglvel_y_en 0660 system system
 /sys/bus/iio/devices/iio:device* scan_elements/in_anglvel_z_en 0660 system system
 /sys/bus/iio/devices/trigger* 	 name 0660 system system
+/sys/class/backlight*		 brightness 0664 system system
 
 /dev/sw_sync              0660   root       graphics
 /dev/iio:device0          0660   system     system