MTK TP驱动移植

对于MTK TP驱动移植一般分为六部分：

1、硬件IO口配置；

2、TP驱动移植；

3、I2C通信；

4、中断触发；

5、数据上报；

6、虚拟按键；

硬件电路：



1、GPIO配置

打开 mediatek\dct\DrvGen.exe 

选择 mediatek\custom\xiaoxi\kernel\dct\dct\codegen.dws 配置文件

配置EINT7_CTP引脚、CTP_RST复位引脚



2、TP驱动移植（以ft5x16为例）

在\mediatek\custom\common\kernel\touchpanel目录下创建ft5x16，将供应商提供的驱动驱动资料拷贝到该目录下；



修改配置文件：mediatek\config\prj\ProjectConfig.mk下的CUSTOM_KERNEL_TOUCHPANEL其值由改为ft5x16，表明对应ft5x16子目录；

打开ft5x16.c文件，修改一下：

static struct i2c_board_info __initdata ft5x16_i2c_tpd={ I2C_BOARD_INFO("ft5x16", (0x70>>1))}; //"ft5x16"为设备名 ，设备地址为高7位

static struct tpd_driver_t tpd_device_driver = {
.tpd_device_name = "FT5x16",
.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
};

/* called when loaded into kernel */
static int __init tpd_driver_init(void) {
printk("MediaTek FT5x16 touch panel driver init\n");
/* 注册板级设备信息 */
i2c_register_board_info(IIC_PORT, &ft5x16_i2c_tpd, 1);  //IIC_PORT表示i2c控制器号，由电路原理图可知TP设备连接到i2c控制器0，ft5x16_i2c_tpd为i2c设备结构，1表示该i2c_board_info个数
if(tpd_driver_add(&tpd_device_driver) < 0)
printk("add FT5x16 driver failed\n");
return 0;
}
</span>

重新编译：./mk n k && ./mk bootimage 

3、I2C通信

新驱动编译进内核，启动内核后，我们怎样验证i2c接口能够正常通信呢？

系统启动后通过串口或adb shell进入系统命令行窗口，查询/sys/bus/i2c/devices目录下是否有0-0038信息，查询/sys/bus/i2c/drivers目录下是否存在‘ft5x16’设备名；先保证i2c能够正常通信；

4、中断触发

中断注册函数：mt_eint_registration(CUST_EINT_TOUCH_PANEL_NUM, CUST_EINT_TOUCH_PANEL_TYPE, tpd_eint_interrupt_handler, 1);

//tpd_eint_interrupt_handler函数为中断回调函数

5、数据上报

当触摸屏产生中断的时候就会调用到该接口；然后在中断处理函数中唤醒运行在子线程中的等待队列，再通过子线程获取TP数据并上报到系统；

static DECLARE_WAIT_QUEUE_HEAD(waiter);  //初始化等待队列

thread = kthread_run(touch_event_handler, 0, TPD_DEVICE);  //新建线程

static int touch_event_handler(void *unused)
{
......
do
{
mt_eint_unmask(CUST_EINT_TOUCH_PANEL_NUM);
set_current_state(TASK_INTERRUPTIBLE);
wait_event_interruptible(waiter,tpd_flag!=0);  //等待队列进入休眠，等待唤醒
tpd_flag = 0;
set_current_state(TASK_RUNNING);
......
if (tpd_touchinfo(&cinfo, &pinfo))   //获取TP数据
{
//TPD_DEBUG("point_num = %d\n",point_num);
TPD_DEBUG_SET_TIME;
if(point_num >0)
{
for(i =0; i<point_num; i++)//only support 3 point
{
cinfo.x[i] = cinfo.x[i];
cinfo.y[i] = cinfo.y[i];

tpd_down(cinfo.x[i], cinfo.y[i], cinfo.id[i]); //上报按下数据
printk(KERN_DEBUG"----calibration----- X:%4d, Y:%4d, P:%4d \n", cinfo.x[i], cinfo.y[i], cinfo.id[i]);
}
input_sync(tpd->dev);
}
else
{
tpd_up(cinfo.x[0], cinfo.y[0]);	  //上报弹起数据
//TPD_DEBUG("release --->\n");
//input_mt_sync(tpd->dev);
input_sync(tpd->dev);
}
}
......

}while(!kthread_should_stop());

return 0;
}

TP数据可以通过打印的方式进行查看，也可以激活‘系统设置’中‘开发者选项’的‘指针位置’，现在触摸操作在LCD的轨迹，也可以在packages\apps\Launcher2\src\com\android\launcher2\Launcher.java的onCreate方法最后添加Settings.System.putInt(this.getContentResolver(),Settings.System.POINTER_LOCATION,
1); 在Launcher中开启‘指针位置’功能（需要mm Launcher模块并重新打包和烧录system.img文件）；

注：如果TP获取到的数据比较乱的时候建议通过打开‘指针位置’功能进行查看，排除TP固件分辨与LCD没对应等问题；

6、虚拟按键

static struct tpd_driver_t tpd_device_driver = {
.tpd_device_name = "FT5x16",
.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
};

从tpd_driver_t结构可知tpd_have_button成员为虚拟按键标志位；由宏TPD_HAVA_BUTTON开关决定的，宏定义在tpd_custom_fts.h中；

在tpd_custom_fts.h中定义了一系列关于虚拟按键的宏：

#define TPD_HAVE_BUTTON  //虚拟按键开关

#define TPD_BUTTON_WIDTH    (200)  //按键宽度

#define TPD_BUTTON_HEIGH    (100)  //按键高度

#define TPD_KEY_COUNT             3       //按键个数

#define TPD_KEYS                        {KEY_MENU, KEY_HOMEPAGE, KEY_BACK}  //按键对应的功能

#define TPD_KEYS_DIM              {{80,900,TPD_BUTTON_WIDTH,TPD_BUTTON_HEIGH}, {240,900,TPD_BUTTON_WIDTH,TPD_BUTTON_HEIGH}, {400,900,TPD_BUTTON_WIDTH,TPD_BUTTON_HEIGH}}  //按键对应位置

TPD_KEYS_DIM中的坐标是该按键区域的中心点：



TP驱动简要分析

static struct tpd_driver_t tpd_device_driver = {
.tpd_device_name = FT5x16,
.tpd_local_init = tpd_local_init,  //初始化函数
.suspend = tpd_suspend,
.resume = tpd_resume,
#ifdef TPD_HAVE_BUTTON
.tpd_have_button = 1,
#else
.tpd_have_button = 0,
#endif
};

/* called when loaded into kernel */
static int __init tpd_driver_init(void) {
printk("MediaTek FT5x16 touch panel driver init\n");
i2c_register_board_info(0, &ft5x16_i2c_tpd, 1);  //注册板级设备信息
if(tpd_driver_add(&tpd_device_driver) < 0)  //添加驱动
printk("add FT5x16 driver failed\n");
return 0;
}

MTK自己编写了一套TP框架，通过该框架管理TP设备，tpd_driver_add为框架的接口之一；系统通过tpd_driver_add添加驱动后会回调tpd_local_init函数；

#ifdef TPD_HAVE_BUTTON
static int tpd_keys_local[TPD_KEY_COUNT] = TPD_KEYS;   //存放按键功能信息
static int tpd_keys_dim_local[TPD_KEY_COUNT][4] = TPD_KEYS_DIM;   //存放虚拟按键信息
#endif

static int tpd_local_init(void)
{
TPD_DMESG("FTS I2C Touchscreen Driver (Built %s @ %s)\n", __DATE__, __TIME__);

if(i2c_add_driver(&tpd_i2c_driver)!=0)  //注册i2c驱动
{
TPD_DMESG("FTS unable to add i2c driver.\n");
return -1;
}
if(tpd_load_status == 0)
{
TPD_DMESG("FTS add error touch panel driver.\n");
i2c_del_driver(&tpd_i2c_driver);
return -1;
}

#ifdef TPD_HAVE_BUTTON      //如果定义虚拟按键，则初始化按键信息
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;
}

向系统注册i2c驱动后，如果找到对应的设备就会调用tpd_probe函数；

static const struct i2c_device_id ft5x16_tpd_id[] = {{TPD_NAME,0},{}};

static struct i2c_driver tpd_i2c_driver = {
.driver = {
.name 	= TPD_NAME,
},
.probe 		= tpd_prob,
.remove 	= __devexit_p(tpd_remove),
.id_table 	= ft5x16_tpd_id,
.detect 	= tpd_detect,
};

static int __devinit tpd_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
int retval = TPD_OK;
char data;
u8 report_rate=0;
int err=0;
int reset_count = 0;
u8 chip_id,i;

reset_proc:
i2c_client = client;
#ifdef MAIERXUN_TP_COM
if(touchpanel_flag){
return 0;
}
#endif
//复位
//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");

//打开TP电源
#ifdef TPD_POWER_SOURCE_CUSTOM
hwPowerOn(TPD_POWER_SOURCE_CUSTOM, VOL_3300, "TP");
#else
hwPowerOn(MT65XX_POWER_LDO_VGP2, VOL_3300, "TP");
#endif

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);

#ifdef TPD_CLOSE_POWER_IN_SLEEP
hwPowerDown(TPD_POWER_SOURCE,"TP");
hwPowerOn(TPD_POWER_SOURCE,VOL_3300,"TP");
msleep(100);

#else  /* 结束复位 */
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);
#endif

/* 初始化中断引脚 */
mt_set_gpio_mode(GPIO_CTP_EINT_PIN, GPIO_CTP_EINT_PIN_M_EINT);
mt_set_gpio_dir(GPIO_CTP_EINT_PIN, GPIO_DIR_IN);
mt_set_gpio_pull_enable(GPIO_CTP_EINT_PIN, GPIO_PULL_ENABLE);
mt_set_gpio_pull_select(GPIO_CTP_EINT_PIN, GPIO_PULL_UP);

/* 中断配置和注册 */
mt_eint_set_hw_debounce(CUST_EINT_TOUCH_PANEL_NUM, CUST_EINT_TOUCH_PANEL_DEBOUNCE_CN);
mt_eint_registration(CUST_EINT_TOUCH_PANEL_NUM, CUST_EINT_TOUCH_PANEL_TYPE, tpd_eint_interrupt_handler, 1);  //注册中断处理函数，TP产生中断时就会回调tpd_eint_interrupt函数
mt_eint_unmask(CUST_EINT_TOUCH_PANEL_NUM);

msleep(400);

err=i2c_smbus_read_i2c_block_data(i2c_client, 0x00, 1, &data);

TPD_DMESG("gao_i2c:err %d,data:%d\n", err,data);
if(err< 0 || data!=0)// reg0 data running state is 0; other state is not 0
{
TPD_DMESG("I2C transfer error, line: %d\n", __LINE__);
#ifdef TPD_RESET_ISSUE_WORKAROUND
if ( reset_count < TPD_MAX_RESET_COUNT )
{
reset_count++;
goto reset_proc;
}
#endif
//add at 20150330 by zhu
#ifdef MAIERXUN_TP_COM
touchpanel_flag=false;
#endif
return -1;
}

......

#ifdef VELOCITY_CUSTOM_FT5206
if((err = misc_register(&tpd_misc_device)))  //注册混杂设备驱动
{
printk("mtk_tpd: tpd_misc_device register failed\n");

}
#endif

#ifdef TPD_AUTO_UPGRADE
printk("********************Enter CTP Auto Upgrade********************\n");
fts_ctpm_auto_upgrade(i2c_client);
#endif
thread = kthread_run(touch_event_handler, 0, TPD_DEVICE);  //创建子线程，通过该子线程获取和上报数据
if (IS_ERR(thread))
{
retval = PTR_ERR(thread);
TPD_DMESG(TPD_DEVICE " failed to create kernel thread: %d\n", retval);
}

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

/* 初始化TP的P-sensor功能，暂不分析 */
#ifdef TPD_PROXIMITY
struct hwmsen_object obj_ps;

obj_ps.polling = 0;//interrupt mode
obj_ps.sensor_operate = tpd_ps_operate;
if((err = hwmsen_attach(ID_PROXIMITY, &obj_ps)))
{
APS_ERR("proxi_fts attach fail = %d\n", err);
}
else
{
APS_ERR("proxi_fts attach ok = %d\n", err);
}
#endif

#ifdef MAIERXUN_TP_COM
touchpanel_flag=true;
#endif

return 0;

}

/* 中断处理函数 */

static void tpd_eint_interrupt_handler(void)
{
//TPD_DEBUG("TPD interrupt has been triggered\n");
TPD_DEBUG_PRINT_INT;
tpd_flag = 1;
wake_up_interruptible(&waiter);  //唤醒等待队列
}

中断处理遵循中断上下文的设计原则，使得中断子程序只是简单唤醒等待队列就可以了，没有多余的操作；

/* 子线程处理函数 */

static int touch_event_handler(void *unused)
{
struct touch_info cinfo, pinfo;
int i=0;

struct sched_param param = { .sched_priority = RTPM_PRIO_TPD };
sched_setscheduler(current, SCHED_RR, ¶m);

#ifdef TPD_PROXIMITY
int err;
hwm_sensor_data sensor_data;
u8 proximity_status;

#endif
u8 state;

do  //进入while循环进行睡眠-等待唤醒的操作
{
mt_eint_unmask(CUST_EINT_TOUCH_PANEL_NUM);  //中断使能（解除屏蔽）
set_current_state(TASK_INTERRUPTIBLE);
wait_event_interruptible(waiter,tpd_flag!=0);  //进入睡眠等待唤醒

tpd_flag = 0;

set_current_state(TASK_RUNNING);
......

#ifdef TPD_PROXIMITY  //TP的P-sensor功能，暂不分析
if (tpd_proximity_flag == 1)
{
i2c_smbus_read_i2c_block_data(i2c_client, 0xB0, 1, &state);
TPD_PROXIMITY_DEBUG("proxi_5206 0xB0 state value is 1131 0x%02X\n", state);

if(!(state&0x01))
{
tpd_enable_ps(1);
}

i2c_smbus_read_i2c_block_data(i2c_client, 0x01, 1, &proximity_status);
TPD_PROXIMITY_DEBUG("proxi_5206 0x01 value is 1139 0x%02X\n", proximity_status);

if (proximity_status == 0xC0)
{
tpd_proximity_detect = 0;
}
else if(proximity_status == 0xE0)
{
tpd_proximity_detect = 1;
}

TPD_PROXIMITY_DEBUG("tpd_proximity_detect 1149 = %d\n", tpd_proximity_detect);

if ((err = tpd_read_ps()))
{
TPD_PROXIMITY_DMESG("proxi_5206 read ps data 1156: %d\n", err);
}
sensor_data.values[0] = tpd_get_ps_value();
sensor_data.value_divide = 1;
sensor_data.status = SENSOR_STATUS_ACCURACY_MEDIUM;
if ((err = hwmsen_get_interrupt_data(ID_PROXIMITY, &sensor_data)))
{
TPD_PROXIMITY_DMESG(" proxi_5206 call hwmsen_get_interrupt_data failed= %d\n", err);
}
}
#endif

if (tpd_touchinfo(&cinfo, &pinfo))   //获取TP设备数据，并把数据保存在cinfob buf中
{
//TPD_DEBUG("point_num = %d\n",point_num);
TPD_DEBUG_SET_TIME;
if(point_num >0)
{
for(i =0; i<point_num; i++)//only support 3 point
{
printk(KERN_DEBUG"X:%4d, Y:%4d, P:%4d \n", cinfo.x[i], cinfo.y[i], cinfo.id[i]);

cinfo.x[i] = cinfo.x[i];
cinfo.y[i] = cinfo.y[i];

tpd_down(cinfo.x[i], cinfo.y[i], cinfo.id[i]);  //按下数据处理
printk(KERN_DEBUG"----calibration----- X:%4d, Y:%4d, P:%4d \n", cinfo.x[i], cinfo.y[i], cinfo.id[i]);
}
input_sync(tpd->dev);
}
else
{
tpd_up(cinfo.x[0], cinfo.y[0]);	//弹起数据处理
//TPD_DEBUG("release --->\n");
//input_mt_sync(tpd->dev);
input_sync(tpd->dev);
}
}
......

}while(!kthread_should_stop());

return 0;
}

/* 获取TP数据 */

static int tpd_touchinfo(struct touch_info *cinfo, struct touch_info *pinfo)
{
int i = 0;
char data[128] = {0};
u16 high_byte,low_byte,reg;
u8 report_rate =0;

p_point_num = point_num;
if (tpd_halt)
{
TPD_DMESG( "tpd_touchinfo return ..\n");
return false;
}
mutex_lock(&i2c_access);

reg = 0x00;
fts_i2c_Read(i2c_client, ®, 1, data, 64);  //获取TP数据，一些TP是支持多点触控的，所以有可能就产生多个触点的数据
mutex_unlock(&i2c_access);

/*get the number of the touch points*/
point_num= data[2] & 0x0f;

TPD_DEBUG("point_num =%d\n",point_num);

/* 根据芯片协议解析数据并存放在cinfo buf中 */
for(i = 0; i < point_num; i++)
{
cinfo->p[i] = data[3+6*i] >> 6; //event flag
cinfo->id[i] = data[3+6*i+2]>>4; //touch id
/*get the X coordinate, 2 bytes*/
high_byte = data[3+6*i];
high_byte <<= 8;
high_byte &= 0x0f00;
low_byte = data[3+6*i + 1];
cinfo->x[i] = high_byte |low_byte;

/*get the Y coordinate, 2 bytes*/
high_byte = data[3+6*i+2];
high_byte <<= 8;
high_byte &= 0x0f00;
low_byte = data[3+6*i+3];
cinfo->y[i] = high_byte |low_byte;
}

}
TPD_DEBUG(" cinfo->x[0] = %d, cinfo->y[0] = %d, cinfo->p[0] = %d\n", cinfo->x[0], cinfo->y[0], cinfo->p[0]);

return true;
}

static  void tpd_down(int x, int y, int p) {
static int tpd_x = 0;
static int tpd_y = 0;

tpd_x = x;
tpd_y = y;

/* 通过输入子系统上报数据 */
input_report_key(tpd->dev, BTN_TOUCH, 1);
input_report_abs(tpd->dev, ABS_MT_TOUCH_MAJOR, 20);
input_report_abs(tpd->dev, ABS_MT_POSITION_X, x);
input_report_abs(tpd->dev, ABS_MT_POSITION_Y, y);

printk(KERN_ERR, "D[%4d %4d %4d] ", x, y, p);
/* track id Start 0 */
input_report_abs(tpd->dev, ABS_MT_TRACKING_ID, p);
input_mt_sync(tpd->dev);
#ifndef MT6572
if (FACTORY_BOOT == get_boot_mode()|| RECOVERY_BOOT == get_boot_mode())
#endif
{
tpd_button(x, y, 1); //虚拟按键的处理
}
TPD_EM_PRINT(x, y, x, y, p-1, 1);
}

static  void tpd_up(int x, int y) {

input_report_key(tpd->dev, BTN_TOUCH, 0);
input_mt_sync(tpd->dev);
TPD_EM_PRINT(x, y, x, y, 0, 0);

#ifndef MT6572
if (FACTORY_BOOT == get_boot_mode()|| RECOVERY_BOOT == get_boot_mode())
#endif
{
tpd_button(x, y, 0);
}
}

/* 虚拟按键判断和处理函数 */

void tpd_button(unsigned int x, unsigned int y, unsigned int down) {
int i;
if(down) {
for(i=0;i<tpd_keycnt;i++)
{
/* 判断数据是否落在虚拟按键的范围内，数据处理算法实现了以坐标点为中心的虚拟按键 */
if(x>=tpd_keys_dim[i][0]-(tpd_keys_dim[i][2]/2) &&
x<=tpd_keys_dim[i][0]+(tpd_keys_dim[i][2]/2) &&
y>=tpd_keys_dim[i][1]-(tpd_keys_dim[i][3]/2) &&
y<=tpd_keys_dim[i][1]+(tpd_keys_dim[i][3]/2) &&
!(tpd->btn_state&(1<<i)))
{
input_report_key(tpd->kpd, tpd_keys[i], 1);  //上报按键
input_sync(tpd->kpd);
tpd->btn_state|=(1<<i);
TPD_DEBUG("[mtk-tpd] press key %d (%d)\n",i, tpd_keys[i]);
printk("[mtk-tpd] press key %d (%d)\n",i, tpd_keys[i]);
}
}
} else {
for(i=0;i<tpd_keycnt;i++) {
if(tpd->btn_state&(1<<i)) {
input_report_key(tpd->kpd, tpd_keys[i], 0);
input_sync(tpd->kpd);
TPD_DEBUG("[mtk-tpd] release key %d (%d)\n",i, tpd_keys[i]);
printk("[mtk-tpd] release key %d (%d)\n",i, tpd_keys[i]);
}
}
tpd->btn_state=0;
}
}
tpd_keys_dim和tpd_keys的数据是通过tpd_button_setting初始化的，可以去看tpd_button_setting()的实现；

通过简单分析，由此可知MTK的TP驱动的整体框架跟普通TP驱动框架也是大致差不多；