Android light系统分析

光线系统包括：背光，闪光，led指示灯

一.内核层

Led-class.c (kernel-3.10\drivers\leds) 这个文件给HAL层提供接口

led_brightness_store是sysfs文件，在"/sys/class/leds/lcd-backlight/brightness"

__led_set_brightness(led_cdev, i);

led_cdev->brightness_set(led_cdev, value); （Leds.h (kernel-3.10\drivers\leds)）

led_cdev->brightness_set在Leds_drv.c (kernel-3.10\drivers\misc\mediatek\leds)中的probe函数中被赋值

g_leds_data[i]->cdev.brightness_set = mt65xx_led_set;

mt65xx_led_set

mt_mt65xx_led_set(led_cdev, level);

mt_mt65xx_led_set_cust(&led_data->cust, led_data->level); 在Leds.c (kernel-3.10\drivers\misc\mediatek\leds\mt6735) 中

mt_mt65xx_led_set_cust //因为我们是GPIO模式，所以就会进入这个分支

case MT65XX_LED_MODE_GPIO:

LEDS_DEBUG("brightness_set_cust:go GPIO mode!!!!!\n");

return ((cust_set_brightness)(cust->data))(level);

cust->data这个函数指针在Cust_leds.c (kernel-3.10\drivers\misc\mediatek\mach\mt6735\lentek6735_65c_l\leds\mt65xx)被赋值

static struct cust_mt65xx_led cust_led_list[MT65XX_LED_TYPE_TOTAL] = {

{"red", MT65XX_LED_MODE_PMIC, MT65XX_LED_PMIC_NLED_ISINK0,{0}},

{"blue", MT65XX_LED_MODE_NONE, -1,{0}},

{"green", MT65XX_LED_MODE_PMIC, MT65XX_LED_PMIC_NLED_ISINK1,{0}},

{"jogball-backlight", MT65XX_LED_MODE_NONE, -1,{0}},

{"keyboard-backlight",MT65XX_LED_MODE_NONE, -1,{0}},

{"button-backlight", MT65XX_LED_MODE_NONE, -1,{0}},

{"lcd-backlight", MT65XX_LED_MODE_GPIO, (long)Cust_Tintele_SetBacklight,{0}},

{"flashlight", MT65XX_LED_MODE_GPIO, (long)Cust_Tintele_SetFlashlight,{0}},

};

因为是16节的控制芯片，就是只有16级亮度，用io模拟这种进行控制

for (; i<=16-level; i++) {

mt_set_gpio_out(GPIO_LCD_BACKLIGHT_EN | 0x80000000, 0);

udelay(2);

mt_set_gpio_out(GPIO_LCD_BACKLIGHT_EN | 0x80000000, 1);

udelay(2);

}

GPIO_LCD_BACKLIGHT_EN | 0x80000000 //是为了让这个执行更快

二.hal层

Lights.c (vendor\mediatek\proprietary\hardware\liblights)

set_light_backlight

write_int(LCD_FILE, brightness); //LCD_FILE就是/sys/class/leds/lcd-backlight/brightness

提供接口给中间层

struct hw_module_t HAL_MODULE_INFO_SYM = {

.tag = HARDWARE_MODULE_TAG,

//.version_major = 1,

//.version_minor = 0,

.id = LIGHTS_HARDWARE_MODULE_ID,

.name = "MTK lights Module",

.author = "MediaTek",

.methods = &lights_module_methods,

};

打开函数

static struct hw_module_methods_t lights_module_methods = {

.open = open_lights,

};

open_lights

if (0 == strcmp(LIGHT_ID_BACKLIGHT, name)) {

set_light = set_light_backlight;

}

三.jni层

init_native

hw_get_module(LIGHTS_HARDWARE_MODULE_ID, (hw_module_t const**)&module); //获得hal层的接口

get_device(module, LIGHT_ID_BACKLIGHT);

module->methods->open(module, name, &device); //调用hal层的open函数

finalize_native 和 setLight_native上层可以调用、

static JNINativeMethod method_table[] = {

{ "init_native", "()J", (void*)init_native },

{ "finalize_native", "(J)V", (void*)finalize_native },

{ "setLight_native", "(JIIIIII)V", (void*)setLight_native },

};

int register_android_server_LightsService(JNIEnv *env)

{

return jniRegisterNativeMethods(env, "com/android/server/lights/LightsService",

method_table, NELEM(method_table));

}

四.framework层

DisplayPowerController.java (frameworks\base\services\core\java\com\android\server\display)

// Brightness animation ramp rate in brightness units per second.

private static final int BRIGHTNESS_RAMP_RATE_FAST = 20000;

private static final int BRIGHTNESS_RAMP_RATE_SLOW = 2000;

我要改变拉动背光条，中间过滤一些数值

巴特西

Android light系统分析

最新文章

热门文章