lights.c revision b514889338b512bdb2550f93c5514af2f1580866 
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
18// #define LOG_NDEBUG 0
19#define LOG_TAG "lights"
20
21#include <cutils/log.h>
22
23#include <stdint.h>
24#include <string.h>
25#include <unistd.h>
26#include <errno.h>
27#include <fcntl.h>
28#include <pthread.h>
29
30#include <sys/ioctl.h>
31#include <sys/types.h>
32
33#include <hardware/lights.h>
34
35/******************************************************************************/
36
37static pthread_once_t g_init = PTHREAD_ONCE_INIT;
38static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
39static struct light_state_t g_notification;
40static struct light_state_t g_battery;
41static int g_attention = 0;
42
43char const*const RED_LED_FILE
44        = "/sys/class/leds/red/brightness";
45
46char const*const GREEN_LED_FILE
47        = "/sys/class/leds/green/brightness";
48
49char const*const BLUE_LED_FILE
50        = "/sys/class/leds/blue/brightness";
51
52char const*const LCD_FILE
53        = "/sys/class/leds/lcd-backlight/brightness";
54
55/**
56 * device methods
57 */
58
59void init_globals(void)
60{
61    // init the mutex
62    pthread_mutex_init(&g_lock, NULL);
63}
64
65static int
66write_int(char const* path, int value)
67{
68    int fd;
69    static int already_warned = 0;
70
71    fd = open(path, O_RDWR);
72    if (fd >= 0) {
73        char buffer[20];
74        int bytes = sprintf(buffer, "%d\n", value);
75        int amt = write(fd, buffer, bytes);
76        close(fd);
77        return amt == -1 ? -errno : 0;
78    } else {
79        if (already_warned == 0) {
80            ALOGE("write_int failed to open %s\n", path);
81            already_warned = 1;
82        }
83        return -errno;
84    }
85}
86
87static int
88is_lit(struct light_state_t const* state)
89{
90    return state->color & 0x00ffffff;
91}
92
93static int
94rgb_to_brightness(struct light_state_t const* state)
95{
96    int color = state->color & 0x00ffffff;
97    return ((77*((color>>16)&0x00ff))
98            + (150*((color>>8)&0x00ff)) + (29*(color&0x00ff))) >> 8;
99}
100
101static int
102set_light_backlight(struct light_device_t* dev,
103        struct light_state_t const* state)
104{
105    int err = 0;
106    int brightness = rgb_to_brightness(state);
107    pthread_mutex_lock(&g_lock);
108    err = write_int(LCD_FILE, brightness);
109    pthread_mutex_unlock(&g_lock);
110    return err;
111}
112
113static int
114set_speaker_light_locked(struct light_device_t* dev,
115        struct light_state_t const* state)
116{
117    int len;
118    int alpha, red, green, blue;
119    int blink, freq, pwm;
120    int onMS, offMS;
121    unsigned int colorRGB;
122
123    switch (state->flashMode) {
124        case LIGHT_FLASH_TIMED:
125            onMS = state->flashOnMS;
126            offMS = state->flashOffMS;
127            break;
128        case LIGHT_FLASH_NONE:
129        default:
130            onMS = 0;
131            offMS = 0;
132            break;
133    }
134
135    colorRGB = state->color;
136
137#if 0
138    ALOGD("set_speaker_light_locked colorRGB=%08X, onMS=%d, offMS=%d\n",
139            colorRGB, onMS, offMS);
140#endif
141
142    red = (colorRGB >> 16) & 0xFF;
143    green = (colorRGB >> 8) & 0xFF;
144    blue = colorRGB & 0xFF;
145
146    // R, G, B value is among 0, 1, 2
147    if (red > 128)  red = 2;
148    else if (red <= 128 && red > 0) red = 1;
149    if (green > 128)  green = 2;
150    else if (green <= 128 && green > 0) green = 1;
151    if (blue > 128)  blue = 2;
152    else if (blue <= 128 && blue > 0) red = 1;
153
154    write_int(RED_LED_FILE, red);
155    write_int(GREEN_LED_FILE, green);
156    write_int(BLUE_LED_FILE, blue);
157
158    // TODO
159    if (onMS > 0 && offMS > 0) {
160        int totalMS = onMS + offMS;
161
162        // the LED appears to blink about once per second if freq is 20
163        // 1000ms / 20 = 50
164        freq = totalMS / 50;
165        // pwm specifies the ratio of ON versus OFF
166        // pwm = 0 -> always off
167        // pwm = 255 => always on
168        pwm = (onMS * 255) / totalMS;
169
170        // the low 4 bits are ignored, so round up if necessary
171        if (pwm > 0 && pwm < 16)
172            pwm = 16;
173
174        blink = 1;
175    } else {
176        blink = 0;
177        freq = 0;
178        pwm = 0;
179    }
180
181    if (blink) {
182        write_int(RED_LED_FILE, freq);
183    }
184
185    return 0;
186}
187
188static void
189handle_speaker_battery_locked(struct light_device_t* dev)
190{
191    if (is_lit(&g_battery)) {
192        set_speaker_light_locked(dev, &g_battery);
193    } else {
194        set_speaker_light_locked(dev, &g_notification);
195    }
196}
197
198static int
199set_light_battery(struct light_device_t* dev,
200        struct light_state_t const* state)
201{
202    pthread_mutex_lock(&g_lock);
203    g_battery = *state;
204    handle_speaker_battery_locked(dev);
205    pthread_mutex_unlock(&g_lock);
206    return 0;
207}
208
209static int
210set_light_notifications(struct light_device_t* dev,
211        struct light_state_t const* state)
212{
213    pthread_mutex_lock(&g_lock);
214    g_notification = *state;
215    handle_speaker_battery_locked(dev);
216    pthread_mutex_unlock(&g_lock);
217    return 0;
218}
219
220static int
221set_light_attention(struct light_device_t* dev,
222        struct light_state_t const* state)
223{
224    pthread_mutex_lock(&g_lock);
225    if (state->flashMode == LIGHT_FLASH_HARDWARE) {
226        g_attention = state->flashOnMS;
227    } else if (state->flashMode == LIGHT_FLASH_NONE) {
228        g_attention = 0;
229    }
230    handle_speaker_battery_locked(dev);
231    pthread_mutex_unlock(&g_lock);
232    return 0;
233}
234
235
236/** Close the lights device */
237static int
238close_lights(struct light_device_t *dev)
239{
240    if (dev) {
241        free(dev);
242    }
243    return 0;
244}
245
246
247/******************************************************************************/
248
249/**
250 * module methods
251 */
252
253/** Open a new instance of a lights device using name */
254static int open_lights(const struct hw_module_t* module, char const* name,
255        struct hw_device_t** device)
256{
257    int (*set_light)(struct light_device_t* dev,
258            struct light_state_t const* state);
259
260    if (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
261        set_light = set_light_backlight;
262    else if (0 == strcmp(LIGHT_ID_BATTERY, name))
263        set_light = set_light_battery;
264    else if (0 == strcmp(LIGHT_ID_NOTIFICATIONS, name))
265        set_light = set_light_notifications;
266    else if (0 == strcmp(LIGHT_ID_ATTENTION, name))
267        set_light = set_light_attention;
268    else
269        return -EINVAL;
270
271    pthread_once(&g_init, init_globals);
272
273    struct light_device_t *dev = malloc(sizeof(struct light_device_t));
274    memset(dev, 0, sizeof(*dev));
275
276    dev->common.tag = HARDWARE_DEVICE_TAG;
277    dev->common.version = 0;
278    dev->common.module = (struct hw_module_t*)module;
279    dev->common.close = (int (*)(struct hw_device_t*))close_lights;
280    dev->set_light = set_light;
281
282    *device = (struct hw_device_t*)dev;
283    return 0;
284}
285
286static struct hw_module_methods_t lights_module_methods = {
287    .open =  open_lights,
288};
289
290/*
291 * The lights Module
292 */
293struct hw_module_t HAL_MODULE_INFO_SYM = {
294    .tag = HARDWARE_MODULE_TAG,
295    .version_major = 1,
296    .version_minor = 0,
297    .id = LIGHTS_HARDWARE_MODULE_ID,
298    .name = "lights Module",
299    .author = "Google, Inc.",
300    .methods = &lights_module_methods,
301};
302