本文转载自:https://blog.csdn.net/qq_33443989/article/details/77074411
1>. 编写灯光系统的HAL层 之 HAL_light.c
1<. 现在的关于灯光系统的JNI访问框架
2<. 涉及的文件
Java android_system_code/frameworks/base/services/core/java/com/android/server/lights/LightsService.java
JNI： android_system_code/frameworks/base/services/core/jni/com_android_server_lights_LightsService.cpp
Hal： lights.c
默认配色：frameworks/base/core/res/res/values/config.xml
电池灯：frameworks/base/services/core/java/com/android/server/BatteryService.java
通知灯：frameworks/base/services/core/java/com/android/server/notification/NotificationManagerService.java
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3<.怎么写代码
1<. 实现一个名为HMI的hw_module_t结构体
2<. 实现一个open函数，他会根据name返回一个light_device_t结构体
3<. 实现多个light_device_t结构体，每个对应一个DEVICE
light_device_t结构体里的第一项是hw_module_t结构体，紧接着一个set_light的函数
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2>. 开始狗血的写代码 : 参考索尼的lights.c
1<. 关键的结构体解释
设置LED状态：
struct light_state_t {
/**
* The color of the LED in ARGB.
*
* Do your best here.
* - If your light can only do red or green, if they ask for blue,
* you should do green.
* - If you can only do a brightness ramp, then use this formula:
* unsigned char brightness = ((77*((color>>16)&0x00ff))
* + (150*((color>>8)&0x00ff)) + (29*(color&0x00ff))) >> 8;
* - If you can only do on or off, 0 is off, anything else is on.
*
* The high byte should be ignored. Callers will set it to 0xff (which
* would correspond to 255 alpha).
*/
unsigned int color; // 把灯设为什么颜色, 或 把LCD的亮度设为什么
/**
* See the LIGHT_FLASH_* constants
*/
int flashMode; // 是否闪烁, LIGHT_FLASH_NONE表示不闪
int flashOnMS; // 亮的时间
int flashOffMS;// 灭的时间
/**
* Policy used by the framework to manage the light's brightness.
* Currently the values are BRIGHTNESS_MODE_USER and BRIGHTNESS_MODE_SENSOR.
*/
int brightnessMode; // 表示LCD的背光亮度模式
};
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2<. 修改函数
set_light_backlight() : 用于控制背光的函数
char const*const LCD_BACKLIGHT_FILE = "/dev/backlight-1wire";
值得一提的是 Tiny4412开发板液晶显示屏采用的是 1线协议 进行处理显示屏数据的
同时它的驱动程序里指明最大亮度设置为127 {
if (v > 127) { //摘抄自Linux3.0.86 tiny4412_1wire_host.c 有厂家提供
v = 127;
}
}
set_light_battery() ：用于处理电量显示的函数
set_light_notifications() ： 用于处理有通知的函数
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3<. 上传 && 编译
1<. 上传
hardware/libhardware/modules/lights/lights.c
hardware/libhardware/modules/lights/Android.mk
Android.mk内容：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := lights.tiny4412
LOCAL_MODULE_RELATIVE_PATH := hw
LOCAL_C_INCLUDEs := hardware/libhardware
LOCAL_SRC_FILES := lights.c
LOCAL_SHARED_LIBRARIES := liblog
LOCAL_MODULE_TAGS := eng
include $(BUILD_SHARED_LIBRARY)
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2<. 修改文件：去掉默认的灯光系统文件
vim vendor/friendly-arm/tiny4412/device-tiny4412.mk
: # $(VENDOR_PATH)/proprietary/lights.tiny4412.so:system/lib/hw/lights.tiny4412.so
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3<. 编译
. setenv
lunch
mmm hardware/libhardware/modules/lights [-B]：强制编译
make snod
./gen-img.sh
4<. 调试
logcat lights:V *:S
[发现问题]：
1<. 打印级别低：
[解决方法]：#define LOG_NDEBUG 0
2<. 权限不够：write_string failed to open /sys/class/leds/led1/trigger
[解决方法]：将linux->led-class.c
修改：led_class_attrs[]数组：
__ATTR(brightness, 0666, led_brightness_show, led_brightness_store),
__ATTR(trigger, 0666, led_trigger_show, led_trigger_store),
[善后工作]将修改过的文件重新上传
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示例代码：
1<. 原厂 lights.c
/*
* Copyright (C) 2008 The Android Open Source Project
* Copyright (C) 2011 Diogo Ferreira <defer@cyanogenmod.com>
* Copyright (C) 2012 The CyanogenMod Project <http://www.cyanogenmod.org>
*
* 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.sony"
#include <cutils/log.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <math.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <hardware/lights.h>
#include "sony_lights.h"
/* Synchronization primities */
static pthread_once_t g_init = PTHREAD_ONCE_INIT;
static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
/* Mini-led state machine */
static struct light_state_t g_notification;
static struct light_state_t g_battery;
/* The leds we have */
enum {
LED_RED,
LED_GREEN,
LED_BLUE,
LED_BLANK
};
const int LCD_BRIGHTNESS_MIN = 10;
static int write_int (const char *path, int value) {
int fd;
static int already_warned = 0;
fd = open(path, O_RDWR);
if (fd < 0) {
if (already_warned == 0) {
ALOGE("write_int failed to open %s\n", path);
already_warned = 1;
}
return -errno;
}
char buffer[20];
int bytes = snprintf(buffer, sizeof(buffer), "%d\n", value);
int written = write (fd, buffer, bytes);
close(fd);
return written == -1 ? -errno : 0;
}
static int write_string (const char *path, const char *value) {
int fd;
static int already_warned = 0;
fd = open(path, O_RDWR);
if (fd < 0) {
if (already_warned == 0) {
ALOGE("write_string failed to open %s\n", path);
already_warned = 1;
}
return -errno;
}
char buffer[20];
int bytes = snprintf(buffer, sizeof(buffer), "%s\n", value);
int written = write (fd, buffer, bytes);
close(fd);
return written == -1 ? -errno : 0;
}
/* Color tools */
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 brightness_apply_gamma (int brightness) {
double floatbrt = (double) brightness;
floatbrt /= 255.0;
ALOGV("%s: brightness = %d, floatbrt = %f", __func__, brightness, floatbrt);
floatbrt = pow(floatbrt,2.2);
ALOGV("%s: gamma corrected floatbrt = %f", __func__, floatbrt);
floatbrt *= 255.0;
brightness = (int) floatbrt;
if (brightness < LCD_BRIGHTNESS_MIN)
brightness = LCD_BRIGHTNESS_MIN;
ALOGV("%s: gamma corrected brightness = %d", __func__, brightness);
return brightness;
}
/* The actual lights controlling section */
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);
if (brightness > 0) {
brightness = brightness_apply_gamma(brightness);
brightness = 4095 * brightness / 255;
}
if (brightness < 188)
brightness = 188;
ALOGV("%s brightness=%d", __func__, brightness);
pthread_mutex_lock(&g_lock);
err |= write_int (LCD_BACKLIGHT_FILE, brightness);
err |= write_int (LCD_BACKLIGHT2_FILE, brightness);
pthread_mutex_unlock(&g_lock);
return err;
}
static int set_light_buttons (struct light_device_t *dev, struct light_state_t const* state) {
return 0;
}
static void set_shared_light_locked (struct light_device_t *dev, struct light_state_t *state) {
int r, g, b, i;
int delayOn, delayOff;
char *pattern=NULL;
char dOn[8],dOff[8];
r = (state->color >> 16) & 0xFF;
g = (state->color >> 8) & 0xFF;
b = (state->color) & 0xFF;
delayOn = state->flashOnMS;
delayOff = state->flashOffMS;
if (state->flashOnMS == 1)
state->flashMode = LIGHT_FLASH_NONE;
else {
//PATTERN=DelayOn,DelayOff,FadeIn,FadeOut
sprintf (dOn,"%d",delayOn);
sprintf (dOff,"%d",delayOff);
asprintf (&pattern,"%s,%s,100,100",dOn,dOff);
ALOGV("pattern=%s",pattern);
}
switch (state->flashMode) {
case LIGHT_FLASH_TIMED:
case LIGHT_FLASH_HARDWARE:
for (i = 0; i < sizeof(LED_FILE_PATTERN)/sizeof(LED_FILE_PATTERN[0]); i++) {
write_string (LED_FILE_PATTERN[i], pattern);
}
break;
case LIGHT_FLASH_NONE:
for (i = 0; i < sizeof(LED_FILE_PATTERN)/sizeof(LED_FILE_PATTERN[0]); i++) {
write_string (LED_FILE_PATTERN[i], PATTERNOFF);
}
break;
}
write_int (RED_LED_FILE, r);
write_int (GREEN_LED_FILE, g);
write_int (BLUE_LED_FILE, b);
}
static void handle_shared_battery_locked (struct light_device_t *dev) {
if (is_lit (&g_notification))
set_shared_light_locked (dev, &g_notification);
else
set_shared_light_locked (dev, &g_battery);
}
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_shared_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_shared_battery_locked(dev);
pthread_mutex_unlock (&g_lock);
return 0;
}
/* Initializations */
void init_globals () {
pthread_mutex_init (&g_lock, NULL);
}
/* Glueing boilerplate */
static int close_lights (struct light_device_t *dev) {
if (dev)
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 (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
set_light = set_light_backlight;
else if (0 == strcmp(LIGHT_ID_BUTTONS, name))
set_light = set_light_buttons;
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
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,
};
struct hw_module_t HAL_MODULE_INFO_SYM = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = LIGHTS_HARDWARE_MODULE_ID,
.name = "Sony lights module",
.author = "Diogo Ferreira <defer@cyanogenmod.com>, Andreas Makris <Andreas.Makris@gmail.com>",
.methods = &lights_module_methods,
};
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2<. 修改后 lights.c
/*
* Copyright (C) 2008 The Android Open Source Project
* Copyright (C) 2011 Diogo Ferreira <defer@cyanogenmod.com>
* Copyright (C) 2012 Andreas Makris <andreas.makris@gmail.com>
* Copyright (C) 2012 The CyanogenMod Project <http://www.cyanogenmod.com>
*
* 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>
char const*const RED_LED_FILE = "/sys/class/leds/led1/brightness";
char const*const GREEN_LED_FILE = "/sys/class/leds/led2/brightness";
char const*const BLUE_LED_FILE = "/sys/class/leds/led3/brightness";
char const*const RED_LED_FILE_TRIGGER = "/sys/class/leds/led1/trigger";
char const*const GREEN_LED_FILE_TRIGGER = "/sys/class/leds/led2/trigger";
char const*const BLUE_LED_FILE_TRIGGER = "/sys/class/leds/led3/trigger";
char const*const RED_LED_FILE_DELAYON = "/sys/class/leds/led1/delay_on";
char const*const GREEN_LED_FILE_DELAYON = "/sys/class/leds/led2/delay_on";
char const*const BLUE_LED_FILE_DELAYON = "/sys/class/leds/led3/delay_on";
char const*const RED_LED_FILE_DELAYOFF = "/sys/class/leds/led1/delay_off";
char const*const GREEN_LED_FILE_DELAYOFF= "/sys/class/leds/led2/delay_off";
char const*const BLUE_LED_FILE_DELAYOFF = "/sys/class/leds/led3/delay_off";
char const*const LCD_BACKLIGHT_FILE = "/dev/backlight-1wire";
/* Synchronization primities */
static pthread_once_t g_init = PTHREAD_ONCE_INIT;
static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
/* Mini-led state machine */
static struct light_state_t g_notification;
static struct light_state_t g_battery;
static int write_int (const char *path, int value) {
int fd;
static int already_warned = 0;
fd = open(path, O_RDWR);
if (fd < 0) {
if (already_warned == 0) {
ALOGE("write_int failed to open %s\n", path);
already_warned = 1;
}
return -errno;
}
char buffer[20];
int bytes = snprintf(buffer, sizeof(buffer), "%d\n", value);
int written = write (fd, buffer, bytes);
close(fd);
return written == -1 ? -errno : 0;
}
static int write_string (const char *path, const char *value) {
int fd;
static int already_warned = 0;
fd = open(path, O_RDWR);
if (fd < 0) {
if (already_warned == 0) {
ALOGE("write_string failed to open %s\n", path);
already_warned = 1;
}
return -errno;
}
char buffer[20];
int bytes = snprintf(buffer, sizeof(buffer), "%s\n", value);
int written = write (fd, buffer, bytes);
close(fd);
return written == -1 ? -errno : 0;
}
/* Color tools */
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;
}
/* The actual lights controlling section */
static int set_light_backlight (struct light_device_t *dev, struct light_state_t const *state) {
int brightness = rgb_to_brightness(state);
ALOGV("%s brightness=%d color=0x%08x", __func__,brightness,state->color);
pthread_mutex_lock(&g_lock);
/* brightness 0-255 */
/* LCD_BACKLIGHT_FILE能接收是0-127 */
write_int (LCD_BACKLIGHT_FILE, brightness/2);
pthread_mutex_unlock(&g_lock);
return 0;
}
static void set_shared_light_locked (struct light_device_t *dev, struct light_state_t *state) {
int r, g, b;
int delayOn,delayOff;
r = (state->color >> 16) & 0xFF;
g = (state->color >> 8) & 0xFF;
b = (state->color) & 0xFF;
delayOn = state->flashOnMS;
delayOff = state->flashOffMS;
if (state->flashMode != LIGHT_FLASH_NONE) {
write_string (RED_LED_FILE_TRIGGER, "timer");
write_string (GREEN_LED_FILE_TRIGGER, "timer");
write_string (BLUE_LED_FILE_TRIGGER, "timer");
write_int (RED_LED_FILE_DELAYON, delayOn);
write_int (GREEN_LED_FILE_DELAYON, delayOn);
write_int (BLUE_LED_FILE_DELAYON, delayOn);
write_int (RED_LED_FILE_DELAYOFF, delayOff);
write_int (GREEN_LED_FILE_DELAYOFF, delayOff);
write_int (BLUE_LED_FILE_DELAYOFF, delayOff);
} else {
write_string (RED_LED_FILE_TRIGGER, "none");
write_string (GREEN_LED_FILE_TRIGGER, "none");
write_string (BLUE_LED_FILE_TRIGGER, "none");
}
write_int (RED_LED_FILE, r);
write_int (GREEN_LED_FILE, g);
write_int (BLUE_LED_FILE, b);
}
static void handle_shared_battery_locked (struct light_device_t *dev) {
if (is_lit (&g_notification)) {
set_shared_light_locked (dev, &g_notification);
} else {
set_shared_light_locked (dev, &g_battery);
}
}
static int set_light_battery (struct light_device_t *dev, struct light_state_t const* state) {
ALOGV("%s flashMode=%d onMS = %d offMS = %d color=0x%08x", __func__,state->flashMode,state->flashOnMS,state->flashOffMS,state->color);
pthread_mutex_lock (&g_lock);
g_battery = *state;
handle_shared_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) {
ALOGV("%s flashMode=%d onMS = %d offMS = %d color=0x%08x", __func__,state->flashMode,state->flashOnMS,state->flashOffMS,state->color);
pthread_mutex_lock (&g_lock);
g_notification = *state;
handle_shared_battery_locked(dev);
pthread_mutex_unlock (&g_lock);
return 0;
}
/* Initializations */
void init_globals () {
pthread_mutex_init (&g_lock, NULL);
}
/* Glueing boilerplate */
static int close_lights (struct light_device_t *dev) {
if (dev)
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 (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 {
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,
};
struct hw_module_t HAL_MODULE_INFO_SYM = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = LIGHTS_HARDWARE_MODULE_ID,
.name = "Sony lights module",
.author = "Diogo Ferreira <defer@cyanogenmod.com>, Andreas Makris <Andreas.Makris@gmail.com>",
.methods = &lights_module_methods,
};