文章來自:http://blog.csdn.net/wh_19910525/article/details/17260861
上一篇我們講了鋰電池的充放電的流程和電池的一些特性,這一節(jié)我們重點說一下android關(guān)機充電是怎么、充電畫面顯示是怎么實現(xiàn)的,這個在工作中也比較有用,我們開始做這一塊的時候也走了不少的彎路。我記得我們做adnroid2.3的時候,關(guān)機狀態(tài)和充電logo顯示是在uboot中做的。應(yīng)該是有兩種做法,回頭我再看下uboot中做畫面顯示那一塊是怎么做的,這一節(jié)我們重點說系統(tǒng)中的充電logo顯示。
一、android正常開機流程、關(guān)機充電流程
在寫這篇文章之前我們先看兩個流程:正常開機流程,關(guān)機充電系統(tǒng)啟動流程
1、正常開機流程,按開機鍵。
可大致分成三部分
(1)、OS_level:UBOOT、kenrel、init這三步完成系統(tǒng)啟動;
(2)、Android_level:這部分完成android部的初始化;
(3)、Home Screen:這部分就是我們看到的launcher部分。
2、關(guān)機充電系統(tǒng)啟動流程
與前面相比,這個流程只走到init這一部分,就沒有往后走了,這部分我們會在后面的代碼中分析。
==========================
二、關(guān)機充電邏輯硬件邏輯
1、插入DC,charger IC從硬件上喚醒系統(tǒng),相當于長按開機鍵開機。
下面這部分是charger IC連接系統(tǒng)的控制部分。
=========================
三、軟件邏輯。
DC插入,其實相當于關(guān)機狀態(tài)下“按開機鍵”開機。第一步要走UBOOT、kernel 、android init這一流程。
1、UBOOT
UBOOT啟動代碼我們不在這里詳細分析,這里我們只要注意二個問題:
a:如何判斷是DC插入;
b:設(shè)定setenv("bootargs", "androidboot.mode=charger"),androidboot.mode這個參數(shù)相當重要,這個參數(shù)決定系統(tǒng)是正常啟動、還是關(guān)機充電狀態(tài)。
Uboot/board/samsung/smdk4212/smkd4212.c
- int board_late_init (void)
- {
- int keystate = 0;
- printf("check start mode\n");
- if ((*(int *)0x10020800==0x19721212) || (*(int *)0x10020804==0x19721212)
- || (*(int *)0x10020808==0x19721212)) //(1)、檢查是否有DC插入;
- {
- setenv ("bootargs", "");//(2)、沒有DC插入;
- } else {//DC插入
- int tmp=*(int *)0x11000c08;
- *(int *)0x10020800=*(int *)0x10020804=0x19721212;
- *(int *)0x11000c08=(tmp&(~0xc000))|0xc000;
- udelay(10000);
- if ((*(int *)0x11000c04 & 0x80)!=0x80 && INF_REG4_REG != 0xf) {
- setenv ("bootargs", "androidboot.mode=charger");//(3)、設(shè)定bootargs為charger狀態(tài)
- printf("charger mode\n");
- } else {
- setenv ("bootargs", "");
- }
- *(int *)0x11000c08=tmp;
- }
- #ifdef CONFIG_CPU_EXYNOS4X12
- int charge_status=CheckBatteryLow();//(4)、檢查電池電量,如果檢測電量太低,則不開機;
- keystate=board_key_check();//(5)、檢查按鍵狀態(tài);
- // fuse bootloader
- if(second_boot_info != 0) {
- boot_symbol=1;
- INF_REG2_REG =0x8;
- run_command(CONFIG_BOOTCMD_FUSE_BOOTLOADER, NULL);
- }
- if((INF_REG4_REG == 0xd)) {
- // reboot default
- char buf[10];
- sprintf(buf, "%d", CONFIG_BOOTDELAY);
- setenv ("bootdelay", buf);
- setenv ("reserved", NULL);
- saveenv();
- } else if((INF_REG4_REG == 0xe) || keystate == (0x1 | 0x2)) {//(6)、按鍵進入fastboot模式;
- // reboot bootloader
- boot_symbol=1;
- INF_REG2_REG =0x8;
- printf("BOOTLOADER - FASTBOOT\n");
- setenv ("reserved", "fastboot");
- setenv ("bootdelay", "0");
- } else if((INF_REG4_REG == 0xf) || keystate == (0x1 | 0x2 | 0x4)) {//(7)、按鍵進入recovery模式;
- // reboot recovery
- printf("BOOTLOADER - RECOVERY\n");
- boot_symbol=1;
- INF_REG2_REG =0x8;
- setenv ("reserved", CONFIG_BOOTCMD_RECOVERY);
- setenv ("bootdelay", "0");
- } else
- if(keystate == (0x1 | 0x4) || second_boot_info != 0 || partition_check()) {//(8)、按鍵進入卡升級模式;
- // 2nd boot
- printf("BOOTLOADER - 2ND BOOT DEVICE\n");
- boot_symbol=1;
- INF_REG2_REG =0x8;
- setenv ("bootcmd", CONFIG_BOOTCOMMAND);
- setenv ("reserved", CONFIG_BOOTCMD_FUSE_RELEASE);
- setenv ("bootdelay", "0");
- } else {//(9)、正常啟動;
- // normal case
- char buf[10];
- sprintf(buf, "%d", CONFIG_BOOTDELAY);
- setenv ("bootdelay", buf);
- }
- INF_REG4_REG = 0;
- return 0;
- }
(1)、檢查是否有DC插入;
- if ((*(int *)0x10020800==0x19721212) || (*(int *)0x10020804==0x19721212)
- (*(int *)0x10020808==0x19721212))
這部分檢查寄存器的值。
(2)、沒有DC插入;
(3)、設(shè)定bootargs為charger狀態(tài)
- if ((*(int *)0x11000c04 & 0x80)!=0x80 && INF_REG4_REG != 0xf) {
- setenv ("bootargs", "androidboot.mode=charger");
這是這部分的重點,如果能過寄存器判斷是DC插入,把androidboot.mode設(shè)定為charger狀態(tài)。
以下這部分根據(jù)需要加入,通過判斷不同的情況進入不同的功能,如fastboot\revovery…………,這部分不做詳細解釋。
(4)、檢查電池電量;
這個在正常開機狀態(tài)下,如果檢測電量太低,則不開機,這部分代碼就不做分析。
(5)、檢查按鍵狀態(tài);
我們這個平臺有幾種模式:fastboot\recovery\卡升級等……
(6)、按鍵進入fastboot模式;
(7)、按鍵進入recovery模式;
(8)、按鍵進入卡升級模式
(9)、正常啟動;
2、kernel
這部分和正常啟動是一樣的。
3、init
前面所有的描述其實只有一點和正常啟動不太一樣,那就是在UBOOT中把androidboot.mode設(shè)定為charger狀態(tài),內(nèi)核正常啟動,然后到init時要對charger這種狀態(tài)處理。
system\core\init\init.c
- int main(int argc, char **argv)
- {
- ………………
- action_for_each_trigger("early-init", action_add_queue_tail);
-
- queue_builtin_action(wait_for_coldboot_done_action, "wait_for_coldboot_done");
- queue_builtin_action(property_init_action, "property_init");
- queue_builtin_action(keychord_init_action, "keychord_init");
- queue_builtin_action(console_init_action, "console_init"); //(1)、顯示initlogo.rle,也就是android第二張圖片;
- queue_builtin_action(set_init_properties_action, "set_init_properties");
-
- /* execute all the boot actions to get us started */
- action_for_each_trigger("init", action_add_queue_tail);
-
- /* skip mounting filesystems in charger mode */
- if (strcmp(bootmode, "charger") != 0) {//(2)、這里就是UBOOT中設(shè)定的bootmode,如果是charger模式,跳過下面初始化;
- action_for_each_trigger("early-fs", action_add_queue_tail);
- action_for_each_trigger("fs", action_add_queue_tail);
- action_for_each_trigger("post-fs", action_add_queue_tail);
- action_for_each_trigger("post-fs-data", action_add_queue_tail);
- }
-
- queue_builtin_action(property_service_init_action, "property_service_init");
- queue_builtin_action(signal_init_action, "signal_init");
- queue_builtin_action(check_startup_action, "check_startup");
-
- if (!strcmp(bootmode, "charger")) {//(3)、如果為charger,則調(diào)用charger.c。
- action_for_each_trigger("charger", action_add_queue_tail);
- } else {
- action_for_each_trigger("early-boot", action_add_queue_tail);
- action_for_each_trigger("boot", action_add_queue_tail);
- }
- ……………………
- }
(1)、顯示initlogo.rle,也就是android第二張圖片;
queue_builtin_action(console_init_action,"console_init");調(diào)用console_init_action
- static int console_init_action(int nargs, char **args)
- {
- int fd;
- char tmp[PROP_VALUE_MAX];
- if (console[0]) {
- snprintf(tmp, sizeof(tmp), "/dev/%s", console);
- console_name = strdup(tmp);
- }
- fd = open(console_name, O_RDWR);
- if (fd >= 0)
- have_console = 1;
- close(fd);
- if( load_565rle_image(INIT_IMAGE_FILE) ) {//這里定義rle文件的名稱#define INIT_IMAGE_FILE "/initlogo.rle"
- fd = open("/dev/tty0", O_WRONLY);
- if (fd >= 0) {//如果沒有這張圖片,就顯示android字樣,在屏幕左上角;
- const char *msg;
- msg = "\n"
- "\n"
- "\n" // console is 40 cols x 30 lines
- "\n"
- "\n"
- "\n"
- "\n"
- "\n"
- "\n"
- "\n"
- " A N D R O I D ";
- write(fd, msg, strlen(msg));
- close(fd);
- }
- }
- return 0;
- }
(2)、這里就是UBOOT中設(shè)定的bootmode,如果是charger模式,跳過下面初始化;
- /* skip mounting filesystems in charger mode */
- if (strcmp(bootmode, "charger") != 0) {
- action_for_each_trigger("early-fs", action_add_queue_tail);
- action_for_each_trigger("fs", action_add_queue_tail);
- action_for_each_trigger("post-fs", action_add_queue_tail);
- action_for_each_trigger("post-fs-data", action_add_queue_tail);
- }
(3)、如果為charger,則調(diào)用charger.c
- action_for_each_trigger("charger", action_add_queue_tail);
我們在后面細分charger這部分。
4、charger.c
這部分就是我們充電部分,充電畫面顯示的實現(xiàn)。
system\core\charger\charger.c
- int main(int argc, char **argv)
- {
- ………………
- klog_set_level(CHARGER_KLOG_LEVEL);
- dump_last_kmsg();
- LOGI("--------------- STARTING CHARGER MODE ---------------\n");
-
- gr_init();
- gr_font_size(&char_width, &char_height); //(1)、初始化graphics,包括buf大小;
-
- ev_init(input_callback, charger);//(2)初始化按鍵;
-
- fd = uevent_open_socket(64*1024, true);
- if (fd >= 0) {
- fcntl(fd, F_SETFL, O_NONBLOCK);
- ev_add_fd(fd, uevent_callback, charger);
- }
-
- charger->uevent_fd = fd;
- coldboot(charger, "/sys/class/power_supply", "add");//(3)、創(chuàng)建/sys/class/power_supply結(jié)點,把socket信息通知應(yīng)用層;
-
- ret = res_create_surface("charger/battery_fail", &charger->surf_unknown);
- if (ret < 0) {
- LOGE("Cannot load image\n");
- charger->surf_unknown = NULL;
- }
- for (i = 0; i < charger->batt_anim->num_frames; i++) {//(4)、這里是顯示charger logo,res_create_surface顯示圖片函數(shù);
- struct frame *frame = &charger->batt_anim->frames[i];
- ret = res_create_surface(frame->name, &frame->surface);
- if (ret < 0) {
- LOGE("Cannot load image %s\n", frame->name);
- /* TODO: free the already allocated surfaces... */
- charger->batt_anim->num_frames = 0;
- charger->batt_anim->num_cycles = 1;
- break;
- }
- }
- ev_sync_key_state(set_key_callback, charger);
- gr_fb_blank(true);
-
- charger->next_screen_transition = now - 1;
- charger->next_key_check = -1;
- charger->next_pwr_check = -1;
- reset_animation(charger->batt_anim);
- kick_animation(charger->batt_anim);
- event_loop(charger);//(5)、event_loop循環(huán),電池狀態(tài),檢測按鍵是否按下;
- return 0;
-
- }
(1)、初始化graphics,包括buf大小
android/bootable/recovery/minui/graphics.c
gr_init():minui/graphics.c[settty0 to graphic mode, open fb0],設(shè)制tty0為圖形模式,打開fb0;
- int gr_init(void)
- {
- gglInit(&gr_context);
- GGLContext *gl = gr_context;
- gr_init_font();
- gr_vt_fd = open("/dev/tty0", O_RDWR | O_SYNC);
- if (gr_vt_fd < 0) {
- // This is non-fatal; post-Cupcake kernels don't have tty0.
- perror("can't open /dev/tty0");
-
- } else if (ioctl(gr_vt_fd, KDSETMODE, (void*) KD_GRAPHICS)) {
- // However, if we do open tty0, we expect the ioctl to work.
- perror("failed KDSETMODE to KD_GRAPHICS on tty0");
- gr_exit();
- return -1;
- }
- gr_fb_fd = get_framebuffer(gr_framebuffer);
- if (gr_fb_fd < 0) {
- gr_exit();
- return -1;
- }
- get_memory_surface(&gr_mem_surface);
- fprintf(stderr, "framebuffer: fd %d (%d x %d)\n",
- gr_fb_fd, gr_framebuffer[0].width, gr_framebuffer[0].height);
- /* start with 0 as front (displayed) and 1 as back (drawing) */
- gr_active_fb = 0;
- set_active_framebuffer(0);
- gl->colorBuffer(gl, &gr_mem_surface);
- gl->activeTexture(gl, 0);
- gl->enable(gl, GGL_BLEND);
- gl->blendFunc(gl, GGL_SRC_ALPHA, GGL_ONE_MINUS_SRC_ALPHA);
- gr_fb_blank(true);
- gr_fb_blank(false);
- return 0;
-
- }
(2)android/bootable/recovery/minui/events.c
ev_init():minui/events.c[open /dev/input/event*]打開 /dev/input/event*
這部分是在,充電狀態(tài)下,按鍵操作的初始化,比如:短按顯示充電logo,長按開機,初始化代碼如下。
- int ev_init(ev_callback input_cb, void *data)
- {
- DIR *dir;
- struct dirent *de;
- int fd;
- dir = opendir("/dev/input");//打開驅(qū)動結(jié)點;
- if(dir != 0) {
- while((de = readdir(dir))) {
- unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];
- // fprintf(stderr,"/dev/input/%s\n", de->d_name);
- if(strncmp(de->d_name,"event",5)) continue;
- fd = openat(dirfd(dir), de->d_name, O_RDONLY);
- if(fd < 0) continue;
- /* read the evbits of the input device */
- if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) < 0) {
- close(fd);
- continue;
- }
- /* TODO: add ability to specify event masks. For now, just assume
- * that only EV_KEY and EV_REL event types are ever needed. */
- if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits)) {
- close(fd);
- continue;
- }
- ev_fds[ev_count].fd = fd;
- ev_fds[ev_count].events = POLLIN;
- ev_fdinfo[ev_count].cb = input_cb;
- ev_fdinfo[ev_count].data = data;
- ev_count++;
- ev_dev_count++;
- if(ev_dev_count == MAX_DEVICES) break;
- }
- }
- return 0;
- }
(3)、創(chuàng)建/sys/class/power_supply結(jié)點,把socket信息通知應(yīng)用層
uevent_open_socket這個函數(shù)是通過kobject_uevent的方式通知的應(yīng)用層,就是往一個socket廣播一個消息,只需要在應(yīng)用層打開socket監(jiān)聽NETLINK_KOBJECT_UEVENT組的消息,就可以收到了,主要是創(chuàng)建了socket接口獲得uevent的文件描述符,然后觸發(fā)/sys/class/power_supply目錄及其子目錄下的uevent,然后接受并創(chuàng)建設(shè)備節(jié)點,至此設(shè)備節(jié)點才算創(chuàng)建。
(4)、這里顯示charger logo,res_create_surface顯示圖片函數(shù);
res_create_surface:minui/resource.c[create surfaces for all bitmaps used later, include icons, bmps]
創(chuàng)建surface為所以的位圖,包括圖標、位圖。 這些圖片的位置為:system\core\charger\images
(5)、event_loop循環(huán),電池狀態(tài),檢測按鍵是否按下;
5、event_loop
這個函數(shù)判斷按鍵狀態(tài),DC是否插拔。如果長按開機:執(zhí)行android_reboot(ANDROID_RB_RESTART,0, 0);如果拔出DC:執(zhí)行android_reboot(ANDROID_RB_POWEROFF,0, 0);
- static void event_loop(struct charger *charger)
- {
- int ret;
- while (true) {
- int64_t now = curr_time_ms();//(1)、獲得當前時間;
- LOGV("[%lld] event_loop()\n", now);
- handle_input_state(charger, now);//(2)、檢查按鍵狀態(tài);
- handle_power_supply_state(charger, now);// (3)、檢查DC是否拔出;
- /* do screen update last in case any of the above want to start
- * screen transitions (animations, etc)
- */
- update_screen_state(charger, now);//(4)、對按鍵時間狀態(tài)標志位的判斷,顯示不同電量的充電logo;
- wait_next_event(charger, now);
- }
- }
(1)、獲得當前時間;
int64_t now = curr_time_ms();
這個時間來判斷,有沒有屏幕超時,如果超時關(guān)閉屏幕充電logo顯示。
(2)、檢查按鍵狀態(tài);
- static void handle_input_state(struct charger *charger, int64_t now)
- {
- process_key(charger, KEY_POWER, now);
- if (charger->next_key_check != -1 && now > charger->next_key_check)
- charger->next_key_check = -1;
- }
- 我們再看下:process_key(charger, KEY_POWER, now);
- static void process_key(struct charger *charger, int code, int64_t now)
- {
- ………………
- if (code == KEY_POWER) {
- if (key->down) {
- int64_t reboot_timeout = key->timestamp + POWER_ON_KEY_TIME;
- if (now >= reboot_timeout) {//如果長按power鍵,就重新啟動,也就是重啟開機;
- LOGI("[%lld] rebooting\n", now);
- android_reboot(ANDROID_RB_RESTART, 0, 0);//重啟命令;
- }
- ………………
- }
-
- key->pending = false;
- }
(3)、檢查DC是否拔出;
handle_power_supply_state(charger, now);
- static void handle_power_supply_state(struct charger *charger, int64_t now)
- {
- if (charger->num_supplies_online == 0) {
- if (charger->next_pwr_check == -1) {
- charger->next_pwr_check = now + UNPLUGGED_SHUTDOWN_TIME;
- LOGI("[%lld] device unplugged: shutting down in %lld (@ %lld)\n",
- now, UNPLUGGED_SHUTDOWN_TIME, charger->next_pwr_check);
- } else if (now >= charger->next_pwr_check) {
- LOGI("[%lld] shutting down\n", now);
- android_reboot(ANDROID_RB_POWEROFF, 0, 0);//如果DC拔出,則關(guān)機;
- }
- ………………
- }
(4)、對按鍵時間狀態(tài)標志位的判斷,顯示不同電量的充電logo;
update_screen_state(charger, now);
這個函數(shù)比較長了,其實做用就是:我們在狀態(tài)的過程中,充電logo的電量是要增加的,比如電量是20%時,要從第一格開始閃爍;如果是80%時,則要從第三格開始閃爍,電量顯示就是通過這個函數(shù)來計算實現(xiàn)的。
- static void update_screen_state(struct charger *charger, int64_t now)
- {
- struct animation *batt_anim = charger->batt_anim;
- int cur_frame;
- int disp_time;
-
- if (!batt_anim->run || now < charger->next_screen_transition)
- return;
-
- /* animation is over, blank screen and leave */
- if (batt_anim->cur_cycle == batt_anim->num_cycles) {
- reset_animation(batt_anim);
- charger->next_screen_transition = -1;
- gr_fb_blank(true);
- LOGV("[%lld] animation done\n", now);
- return;
- }
-
- disp_time = batt_anim->frames[batt_anim->cur_frame].disp_time;
-
- /* animation starting, set up the animation */
- if (batt_anim->cur_frame == 0) {
- int batt_cap;
- int ret;
-
- LOGV("[%lld] animation starting\n", now);
- batt_cap = get_battery_capacity(charger);
- if (batt_cap >= 0 && batt_anim->num_frames != 0) {
- int i;
-
- /* find first frame given current capacity */
- for (i = 1; i < batt_anim->num_frames; i++) {
- if (batt_cap < batt_anim->frames[i].min_capacity)
- break;
- }
- batt_anim->cur_frame = i - 1;
-
- /* show the first frame for twice as long */
- disp_time = batt_anim->frames[batt_anim->cur_frame].disp_time * 2;
- }
-
- batt_anim->capacity = batt_cap;
- }
-
- /* unblank the screen on first cycle */
- if (batt_anim->cur_cycle == 0)
- gr_fb_blank(false);
-
- /* draw the new frame (@ cur_frame) */
- redraw_screen(charger);
-
- /* if we don't have anim frames, we only have one image, so just bump
- * the cycle counter and exit
- */
- if (batt_anim->num_frames == 0 || batt_anim->capacity < 0) {
- LOGV("[%lld] animation missing or unknown battery status\n", now);
- charger->next_screen_transition = now + BATTERY_UNKNOWN_TIME;
- batt_anim->cur_cycle++;
- return;
- }
-
- /* schedule next screen transition */
- charger->next_screen_transition = now + disp_time;
-
- /* advance frame cntr to the next valid frame
- * if necessary, advance cycle cntr, and reset frame cntr
- */
- batt_anim->cur_frame++;
-
- /* if the frame is used for level-only, that is only show it when it's
- * the current level, skip it during the animation.
- */
- while (batt_anim->cur_frame < batt_anim->num_frames &&
- batt_anim->frames[batt_anim->cur_frame].level_only)
- batt_anim->cur_frame++;
- if (batt_anim->cur_frame >= batt_anim->num_frames) {
- batt_anim->cur_cycle++;
- batt_anim->cur_frame = 0;
-
- /* don't reset the cycle counter, since we use that as a signal
- * in a test above to check if animation is over
- */
- }
- }
下面是 不同 電量時 顯示logo的函數(shù):
- static struct frame batt_anim_frames[] = {
- {
- .name = "charger/battery_0",
- .disp_time = 750,
- .min_capacity = 0,
- },
- {
- .name = "charger/battery_1",
- .disp_time = 750,
- .min_capacity = 20,
- },
- {
- .name = "charger/battery_2",
- .disp_time = 750,
- .min_capacity = 40,
- },
- {
- .name = "charger/battery_3",
- .disp_time = 750,
- .min_capacity = 60,
- },
- {
- .name = "charger/battery_4",
- .disp_time = 750,
- .min_capacity = 80,
- .level_only = true,
- },
- {
- .name = "charger/battery_5",
- .disp_time = 750,
- .min_capacity = BATTERY_FULL_THRESH,
- },
- };