基於MTK 的 TP 驅動分析

1. 克隆服務器工程源碼並切換分支 

git clone [email protected]: mt658292_kk v9 

git checkout -b submit_v9_dongxf_tp_modify_v1.0_2014_0910 origin/v6_dev

2. TP 硬件分析

1）硬件圖：

 

2）硬件管腳：

    SCL0: IIC 時鐘引腳

    SDA0:IIC數據引腳

    RST: 復位引腳

    EINT: IIC 中斷引腳，觸摸事件通過IIC 貫穿到系統

   

3. 需要分析的文件：

1）MTK 關於TP的框架文件：實現對input的初始化，具體的 TP IC匹配操作

v9/code/mediatek/custom/common/kernel/touchpanel/src/mtk_tpd.c

2）具體TP IC的 設置我們可以進行IC的上電、設置中斷、UpdateFW等動作

v9/code/mediatek/custom/common/kernel/touchpanel/ft5206(TPdevicename)/focaltech_ex_fun.c

3）TP的配置文件: 設計屏幕分辨率，虛擬按鍵設置

v9/code/mediatek/custom/v9_e324_3gb15_qhd_cq4153(projectname)/kernel/touchpanel/ft5206(TPdevicename)/tpd_custom_ft5206.h

配置示例：

#define TPD_HAVE_BUTTON                //　定義該宏表示我們的TP支持虛擬按鍵
#define TPD_BUTTON_HEIGH       (100)
#define TPD_KEY_COUNT          3       //支持的虛擬按鍵的個數
#define TPD_KEYS                {KEY_MENU, KEY_HOMEPAGE ,KEY_BACK} //對應的功能鍵
#define  TPD_KEYS_DIM                  //每個功能鍵的座標
           {{90,1010,120,TPD_BUTTON_HEIGH},
           {270,1010,120,TPD_BUTTON_HEIGH},
           {450,1010,120,TPD_BUTTON_HEIGH}}//四個參數分別爲x座標，y座標，width，height

3. TP 工作原理：

       Kernel 通過input 子系統與android交互，每當我們點擊屏幕或擡起都會產生中斷，每當kernel收到中斷會通過i2c總線讀取TP控制器產生的座標數據，kernel就會通過input系統上報給android層， android層會完成相應的動作。

      Android手機TP一般會涉及虛擬按鍵的操作，初始化時會通過tpd_button_settings(),根據定義在tpd _custom_ft5206.h 文件中的配置信息將虛擬按鍵的座標信息寫在/sys/board_properities/virtualkeys. mtk-tpd中，android層再工作時判斷上報的座標是否屬於在某個按鍵的範圍內，如果在這個範圍內，會轉換成相應的button事件

 

4. 驅動框架分析 //按照執行順序的先後,對於某一款TP的驅動，系統加載後會調用其中的初始化部分，以ft5206爲例

1） TP  初始化 

//v9/code/mediatek/custom/common/kernel/touchpanel/ft5206/focaltech_driver.c

/*called when loaded into kernel */
static int __init tpd_driver_init(void) {
         printk("MediaTekFTS touch panel driver init\n");
         i2c_register_board_info(TPD_I2C_NUMBER,&ft5206_i2c_tpd, 1);  //這個ft5206_i2c_tpd添加到全局的i2c設備鏈表__i2c_board_list中
         if(tpd_driver_add(&tpd_device_driver)< 0)  //這個比較重要，在下面的第4步中進行tpd_i2c_driver驅動的i2c總線註冊會匹配這個i2c總線設備。
                   TPD_DMESG("addFTS driver failed\n");
          return 0;
 }

static struct i2c_driver tpd_i2c_driver = {
       .driver = {
                 .name    = "mtk-focal",
       },
       .probe     =tpd_probe,
       .remove =tpd_remove,
       .id_table          =ft5206_tpd_id,
       .detect    =tpd_detect,
};

struct tpd_driver_t tpd_device_driver = {
         .tpd_device_name= "mtk-focal",
         .tpd_local_init= tpd_local_init,
         .suspend= tpd_suspend,
         .resume= tpd_resume,
#ifdef TPD_HAVE_BUTTON
         .tpd_have_button= 1,
#else
         .tpd_have_button= 0,
#endif
 };

 2） TP 設備加載、卸載和平臺總線註冊

//W:\.dongxunfeng\v9\code\mediatek\custom\common\kernel\touchpanel\src\mtk_tpd.c

/* should never be called */
static void __exit tpd_device_exit(void) {
   TPD_DMESG("MediaTek touch panel driver exit\n");
   //input_unregister_device(tpd->dev);
   platform_driver_unregister(&tpd_driver);
   #ifdef CONFIG_HAS_EARLYSUSPEND
   unregister_early_suspend(&MTK_TS_early_suspend_handler);
   #endif
}

/* called when loaded into kernel */
static int __init tpd_device_init(void) {
   printk("MediaTek touch panel driver init\n");
   rgk_creat_proc_tp_info();
   if(platform_driver_register(&tpd_driver)!=0) {
       TPD_DMESG("unable to register touch panel driver.\n");
       return -1;
   }
   return 0;
}

/* called when loaded into kernel */
static struct platform_driver tpd_driver ={
   .remove     = tpd_remove,
   .shutdown   = NULL,
   .probe      = tpd_probe,
   #ifndef CONFIG_HAS_EARLYSUSPEND
   .suspend    = NULL,
   .resume     = NULL,
   #endif
   .driver     = {
       .name = TPD_DEVICE,
   },
};

//tpd_driver對應的虛擬總線設備在文件  

//code/mediatek/platform/mt6582/kernel/core/mt_devs.c

/*=======================================================================*/
/* MT6575 Touch Panel                                                    */
/*=======================================================================*/

static struct platform_device mtk_tpd_dev ={
   .name = "mtk-tpd",  //二者name 字段匹配成功後執行tpd_driver中的probe函數
   .id   = -1,
};

#if defined(CONFIG_MTK_TOUCHPANEL)
   retval = platform_device_register(&mtk_tpd_dev);
   if (retval != 0) {
       return retval;
    }
#endif

3) tpd_driver中的probe函數分析（只提取probe函數部分內容）

 

struct tpd_device  *tpd = 0;

/* touch panel probe */
static int tpd_probe(struct platform_device*pdev) {
         ...
   ...
   if((tpd=(struct tpd_device*)kmalloc(sizeof(struct tpd_device),GFP_KERNEL))==NULL) return -ENOMEM;
   memset(tpd, 0, sizeof(struct tpd_device));

   /* allocate input device */
   if((tpd->dev=input_allocate_device())==NULL) { kfree(tpd); return-ENOMEM; } //TP設備抽象爲tpd結構體

 //TPD_RES_X = simple_strtoul(LCM_WIDTH, NULL, 0);
 //TPD_RES_Y = simple_strtoul(LCM_HEIGHT, NULL, 0);
 TPD_RES_X = DISP_GetScreenWidth();
   TPD_RES_Y = DISP_GetScreenHeight();


   printk("mtk_tpd: TPD_RES_X = %d, TPD_RES_Y = %d\n", TPD_RES_X,TPD_RES_Y);

   tpd_mode = TPD_MODE_NORMAL;
   tpd_mode_axis = 0;
   tpd_mode_min = TPD_RES_Y/2;
   tpd_mode_max = TPD_RES_Y;
   tpd_mode_keypad_tolerance = TPD_RES_X*TPD_RES_X/1600;
   /* struct input_dev dev initialization and registration */
   tpd->dev->name = TPD_DEVICE;      // 爲TP設備分配一個輸入設備
   set_bit(EV_ABS, tpd->dev->evbit); // 輸入設備的初始化，重點是對輸入設備進行 KEY 和 ABS 兩種輸入類型的初始化
   set_bit(EV_KEY, tpd->dev->evbit);
   set_bit(ABS_X, tpd->dev->absbit);
   set_bit(ABS_Y, tpd->dev->absbit);
   set_bit(ABS_PRESSURE, tpd->dev->absbit);
   set_bit(BTN_TOUCH, tpd->dev->keybit);
   ....

 /**************************************************************************

  *    全局數組tpd_driver_lsit[i]中的tp驅動依次進行如下操作 ,遍歷整個數組

  * 執行tp驅動中的tpd_local_init()接口，此接口主要是對tpd_i2c_driver進行i2c

  * 總線的註冊,匹配成功後執行tpd_i2c_driver中的probe ，這個probe比較重要，

  * 其中系統會跟TP進行一次i2c通信，如果成功則說明找到了這個驅動，根據

  * 此，可以兼容多款不同IC的TP設備

  **************************************************************************/    

#if 1
 for(i = 1; i < TP_DRV_MAX_COUNT; i++)
         {
       /* add tpd driver into list */
       if(tpd_driver_list[i].tpd_device_name != NULL)
       {
#if 1//lisong 2014-3-10 [BUGID:NULL][fixbug:can not go into meta mode if TP disconnected ]start
           if(boot_mode == META_BOOT)
           {/*reserved*/}
           else
#endif//lisong 2014-3-10 [BUGID:NULL][fixbug:can not go into meta mode if TP disconnected ]end
               tpd_driver_list[i].tpd_local_init();        //執行tp驅動中的tpd_local_init()接口
           //msleep(1);
           if(tpd_load_status ==1) { // 如果上面的i2c總線註冊成功，則將tpd_load_status置位，並將g_tpd_drv指向這個驅動
               TPD_DMESG("[mtk-tpd]tpd_probe, tpd_driver_name=%s\n",tpd_driver_list[i].tpd_device_name);
                g_tpd_drv =&tpd_driver_list[i];
                break;
           }
       }
    }
   if(g_tpd_drv == NULL) { //如果 g_tpd_drv 爲空，說明沒有找到匹配的驅動
       if(tpd_driver_list[0].tpd_device_name != NULL) {
           g_tpd_drv = &tpd_driver_list[0]; //沒有找到匹配的驅動，指定 鏈表首元素作爲默認的驅動程序
           /* touch_type:0: r-touch, 1: C-touch */
           touch_type = 0;
           g_tpd_drv->tpd_local_init();
           TPD_DMESG("[mtk-tpd]Generic touch panel driver\n");
       } else {
           TPD_DMESG("[mtk-tpd]cap touch and Generic touch both are notloaded!!\n");
           return 0;
       }
    }

    strncpy(mtk_tpd_ic_name,(char*)g_tpd_drv->tpd_device_name,sizeof(mtk_tpd_ic_name)-1);// zhoulidong add

   #ifdef CONFIG_HAS_EARLYSUSPEND
   MTK_TS_early_suspend_handler.suspend = g_tpd_drv->suspend;
   MTK_TS_early_suspend_handler.resume = g_tpd_drv->resume;
   register_early_suspend(&MTK_TS_early_suspend_handler);
   #endif

#ifdef TPD_TYPE_CAPACITIVE
         /*TPD_TYPE_CAPACITIVE handle */
         if(touch_type== 1){

         set_bit(ABS_MT_TRACKING_ID,tpd->dev->absbit);  //對輸入設備初始化
             set_bit(ABS_MT_TOUCH_MAJOR,tpd->dev->absbit);
         ....
#if 0 // linux kernel update from 2.6.35--> 3.0
             tpd->dev->absmax[ABS_MT_POSITION_X]= TPD_RES_X;
         ....
#else
         input_set_abs_params(tpd->dev,ABS_MT_POSITION_X, 0, TPD_RES_X, 0, 0); //再次對輸入設備初始化
                   ....
#endif
             TPD_DMESG("Cap touch paneldriver\n");
       }
#endif
   #if 0 //linux kernel update from 2.6.35 --> 3.0
   tpd->dev->absmax[ABS_X] = TPD_RES_X;
   tpd->dev->absmin[ABS_X] = 0;
   tpd->dev->absmax[ABS_Y] = TPD_RES_Y;
   tpd->dev->absmin[ABS_Y] = 0;

   tpd->dev->absmax[ABS_PRESSURE] = 255;
   tpd->dev->absmin[ABS_PRESSURE] = 0;
   #else
         input_set_abs_params(tpd->dev,ABS_X, 0, TPD_RES_X, 0, 0);  //再次對輸入設備初始化
         input_set_abs_params(tpd->dev,ABS_Y, 0, TPD_RES_Y, 0, 0);
         input_abs_set_res(tpd->dev,ABS_X, TPD_RES_X);
            ....

   #endif
   if(input_register_device(tpd->dev))   //向輸入子系統註冊輸入設備
       TPD_DMESG("input_register_device failed.(tpd)\n");
   else
                            tpd_register_flag= 1;
   /* init R-Touch */
   #if 0
           if(touch_type == 0)
           {
                g_tpd_drv->tpd_local_init();
           }
                   #endif
   if(g_tpd_drv->tpd_have_button)
    {
             tpd_button_init();
    }

         if(g_tpd_drv->attrs.num)
                   tpd_create_attributes(&pdev->dev,&g_tpd_drv->attrs);

   return 0;
}

4) 觸摸事件觸發實現

//依次執行其中的tpd_local_init()接口，此接口是對tpd_i2c_driver(下面會提到這個結構體)進行i2c總

線的註冊，先匹配id,若無則匹配name，匹配成功後執行tpd_i2c_driver驅動中的tpd_probe接口

int tpd_local_init(void)
{
    // 對 tpd_i2c_driver 進行註冊
   if(i2c_add_driver(&tpd_i2c_driver)!=0) {
     TPD_DMESG("unable to add i2c driver.\n");
     return -1;
    }

   if (0) //if(tpd_load_status == 0)
    {
             TPD_DMESG("add error touch paneldriver.\n");
             i2c_del_driver(&tpd_i2c_driver);
             return -1;
    }

#ifdef TPD_HAVE_BUTTON
   tpd_button_setting(TPD_KEY_COUNT, tpd_keys_local, tpd_keys_dim_local);//initialize tpd button data
#endif

#if (defined(TPD_WARP_START) &&defined(TPD_WARP_END))
   TPD_DO_WARP = 1;
   memcpy(tpd_wb_start, tpd_wb_start_local, TPD_WARP_CNT*4);
   memcpy(tpd_wb_end, tpd_wb_start_local, TPD_WARP_CNT*4);
#endif

#if (defined(TPD_HAVE_CALIBRATION)&& !defined(TPD_CUSTOM_CALIBRATION))
   memcpy(tpd_calmat, tpd_def_calmat_local, 8*4);
   memcpy(tpd_def_calmat, tpd_def_calmat_local, 8*4);
#endif
   TPD_DMESG("end %s, %d\n", __FUNCTION__, __LINE__);
   tpd_type_cap = 1;
   return 0;
}

// tpd_i2c_driver 初始化
static struct i2c_driver tpd_i2c_driver = {
       .driver = {
                 .name    = "mtk-focal",
       },
       .probe     =tpd_probe,
       .remove =tpd_remove,
       .id_table          =ft5206_tpd_id,
       .detect    =tpd_detect,
};


// tpd_probe 的定義
static int tpd_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
         intretval = TPD_OK;
         chardata;
         intreset_count = 0;

         client->timing= 300;
         i2c_client= client;
reset_proc:

      //power on, need confirm with SA
      mt_set_gpio_mode(GPIO_CTP_RST_PIN, GPIO_CTP_RST_PIN_M_GPIO);
      mt_set_gpio_dir(GPIO_CTP_RST_PIN, GPIO_DIR_OUT);
      mt_set_gpio_out(GPIO_CTP_RST_PIN, GPIO_OUT_ZERO);
      msleep(5);
      TPD_DMESG(" fts ic reset\n");


      mt_set_gpio_mode(GPIO_CTP_RST_PIN, GPIO_CTP_RST_PIN_M_GPIO);
      mt_set_gpio_dir(GPIO_CTP_RST_PIN, GPIO_DIR_OUT);
      mt_set_gpio_out(GPIO_CTP_RST_PIN, GPIO_OUT_ONE);

      msleep(200);

      if((i2c_smbus_read_i2c_block_data(i2c_client, 0x00, 1, &data))<0)  //系統和TP通過 IIC 通信，若通信失敗則認爲TP　設備未連接到主板
     {
                   TPD_DMESG("I2Ctransfer error, line: %d\n", __LINE__);
#ifdef TPD_RESET_ISSUE_WORKAROUND
       if ( reset_count < TPD_MAX_RESET_COUNT )
       {
           reset_count++;
           goto reset_proc;
       }
#endif
                      return -1;
         }

         mt_set_gpio_mode(GPIO_CTP_EINT_PIN,GPIO_CTP_EINT_PIN_M_EINT);  //設置引腳中斷
         mt_set_gpio_dir(GPIO_CTP_EINT_PIN,GPIO_DIR_IN);
         mt_set_gpio_pull_enable(GPIO_CTP_EINT_PIN,GPIO_PULL_ENABLE); //打開中斷使能
         mt_set_gpio_pull_select(GPIO_CTP_EINT_PIN,GPIO_PULL_UP);  //設定中斷觸發方式

 　         // 註冊中斷處理函數，作用是 喚醒(wake up interrupt)等待隊列，等待隊列頭上懸掛着觸摸事件的等待隊列
        mt_eint_registration(CUST_EINT_TOUCH_PANEL_NUM,CUST_EINT_TOUCH_PANEL_TYPE, tpd_eint_interrupt_handler, 0);
        mt_eint_unmask(CUST_EINT_TOUCH_PANEL_NUM);

         ....

         #ifdefTPD_AUTO_UPGRADE
         thread= kthread_run(tpd_ft_update_fw, 0, TPD_DEVICE);
         if(IS_ERR(thread))
         {
                   retval= PTR_ERR(thread);
                   TPD_DMESG(TPD_DEVICE" failed to create kernel thread for update fw: %d\n", retval);
         }
         #endif

         thread= kthread_run(touch_event_handler, 0, TPD_DEVICE); //創建一個內核中運行的線程，這個線程主要是實現觸摸事件發生時，採集觸摸點數
         if(IS_ERR(thread))
         {
                   retval= PTR_ERR(thread);
                   TPD_DMESG(TPD_DEVICE" failed to create kernel thread: %d\n", retval);
         }

         TPD_DMESG("FTSTouch Panel Device Probe %s\n", (retval < TPD_OK) ? "FAIL" :"PASS");

       ....

  return 0;

 }

//觸摸中斷事件處理函數：tpd_eint_interrupt_handler
static voidtpd_eint_interrupt_handler(void)
{
         //TPD_DEBUG("TPDinterrupt has been triggered\n");
         TPD_DEBUG_PRINT_INT;
         tpd_flag= 1;     //將標誌位置位
         wake_up_interruptible(&waiter);  // 喚醒等待隊列
}

//觸摸事件 採集線程
static int touch_event_handler(void*unused)
 {
         ....
         sched_setscheduler(current,SCHED_RR, ¶m);
        ....

         do
         {
                   set_current_state(TASK_INTERRUPTIBLE);   //設置當前線程睡眠
                   wait_event_interruptible(waiter,tpd_flag!=0);       // 設置等待隊列等待事件，tpd_flag 會在中斷處理函數中置位
                   tpd_flag= 0;
                   set_current_state(TASK_RUNNING);


                   if(tpd_touchinfo(&cinfo, &pinfo, &point_num))              //獲得多點觸控信息
                   {
                                //TPD_DEBUG("point_num= %d\n",point_num);
                            TPD_DEBUG_SET_TIME;
                            if(point_num>0)
                            {
                                for(i =0; i<point_num; i++)
                                {
                                     tpd_down(cinfo.x[i], cinfo.y[i],cinfo.id[i]); //上傳多點觸控信息
                                }
                               input_sync(tpd->dev);
                            }
                            else
                                {
                                tpd_up(cinfo.x[0], cinfo.y[0]);  //上傳一個觸控信息
                                 input_sync(tpd->dev);
                          }
                }
        mt_eint_unmask(CUST_EINT_TOUCH_PANEL_NUM);
        }while(!kthread_should_stop());
         return0;
}