1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "lights"
18 #include <cutils/log.h>
19 #include <stdint.h>
20 #include <string.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <pthread.h>
24 #include <sys/ioctl.h>
25 #include <sys/types.h>
26 #include <hardware/lights.h>
27
28 static pthread_once_t g_init = PTHREAD_ONCE_INIT;
29 static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
30
31 char const *const LCD_FILE = "/sys/class/backlight/s5p_bl/brightness";
32
write_int(char const * path,int value)33 static int write_int(char const *path, int value)
34 {
35 int fd;
36 static int already_warned;
37
38 already_warned = 0;
39
40 LOGV("write_int: path %s, value %d", path, value);
41 fd = open(path, O_RDWR);
42
43 if (fd >= 0) {
44 char buffer[20];
45 int bytes = sprintf(buffer, "%d\n", value);
46 int amt = write(fd, buffer, bytes);
47 close(fd);
48 return amt == -1 ? -errno : 0;
49 } else {
50 if (already_warned == 0) {
51 LOGE("write_int failed to open %s\n", path);
52 already_warned = 1;
53 }
54 return -errno;
55 }
56 }
57
rgb_to_brightness(struct light_state_t const * state)58 static int rgb_to_brightness(struct light_state_t const *state)
59 {
60 int color = state->color & 0x00ffffff;
61
62 return ((77*((color>>16) & 0x00ff))
63 + (150*((color>>8) & 0x00ff)) + (29*(color & 0x00ff))) >> 8;
64 }
65
set_light_backlight(struct light_device_t * dev,struct light_state_t const * state)66 static int set_light_backlight(struct light_device_t *dev,
67 struct light_state_t const *state)
68 {
69 int err = 0;
70 int brightness = rgb_to_brightness(state);
71
72 pthread_mutex_lock(&g_lock);
73 err = write_int(LCD_FILE, brightness);
74
75 pthread_mutex_unlock(&g_lock);
76 return err;
77 }
78
close_lights(struct light_device_t * dev)79 static int close_lights(struct light_device_t *dev)
80 {
81 LOGV("close_light is called");
82 if (dev)
83 free(dev);
84
85 return 0;
86 }
87
open_lights(const struct hw_module_t * module,char const * name,struct hw_device_t ** device)88 static int open_lights(const struct hw_module_t *module, char const *name,
89 struct hw_device_t **device)
90 {
91 int (*set_light)(struct light_device_t *dev,
92 struct light_state_t const *state);
93
94 LOGV("open_lights: open with %s", name);
95
96 if (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
97 set_light = set_light_backlight;
98 else
99 return -EINVAL;
100
101 pthread_mutex_init(&g_lock, NULL);
102
103 struct light_device_t *dev = malloc(sizeof(struct light_device_t));
104 memset(dev, 0, sizeof(*dev));
105
106 dev->common.tag = HARDWARE_DEVICE_TAG;
107 dev->common.version = 0;
108 dev->common.module = (struct hw_module_t *)module;
109 dev->common.close = (int (*)(struct hw_device_t *))close_lights;
110 dev->set_light = set_light;
111
112 *device = (struct hw_device_t *)dev;
113
114 return 0;
115 }
116
117 static struct hw_module_methods_t lights_module_methods = {
118 .open = open_lights,
119 };
120
121 const struct hw_module_t HAL_MODULE_INFO_SYM = {
122 .tag = HARDWARE_MODULE_TAG,
123 .version_major = 1,
124 .version_minor = 0,
125 .id = LIGHTS_HARDWARE_MODULE_ID,
126 .name = "lights Module",
127 .author = "Google, Inc.",
128 .methods = &lights_module_methods,
129 };
130