rk3188--6.android 触摸屏驱动分析

在drivers/input/touchscreen/ft5302_tp/ft5302_ts.c中
module_init(ft5x0x_ts_init);

static int __init ft5x0x_ts_init(void)
{
    ret = i2c_add_driver(&ft5x0x_ts_driver);
    return ret;
}

其中ft5x0x_ts_driver结构如下:

static struct i2c_driver ft5x0x_ts_driver = {
    .probe        = ft5x0x_ts_probe,
    .remove        = __devexit_p(ft5x0x_ts_remove),
    .id_table    = ft5x0x_ts_id,
    .driver    = {
        .name    = FT5X0X_NAME,
        .owner    = THIS_MODULE,
    },
};

在probe函数中

static int ft5x0x_ts_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    struct ft5x0x_ts_dev *ft5x0x_ts;
    struct ft5x0x_platform_data *pdata = pdata = client->dev.platform_data;
    struct input_dev *input_dev;
    u8 buf_w[1];
    u8 buf_r[1];
    unsigned char reg_value;
    unsigned char reg_version;
    int result, irq = 0;

    ft5x0x_ts = (struct ft5x0x_ts_dev *)kzalloc(sizeof(*ft5x0x_ts), GFP_KERNEL);
    input_dev = input_allocate_device();
    ft5x0x_ts->input_dev = input_dev;
    ft5x0x_ts->client = this_client = client;
    ft5x0x_ts->irq = client->irq;

    __set_bit(EV_ABS, input_dev->evbit);
    __set_bit(EV_KEY, input_dev->evbit);
    __set_bit(EV_REP, input_dev->evbit);
    __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
    set_bit(ABS_MT_POSITION_X, input_dev->absbit);
    set_bit(ABS_MT_POSITION_Y, input_dev->absbit);
    set_bit(ABS_MT_TOUCH_MAJOR, input_dev->absbit);
    set_bit(ABS_MT_WIDTH_MAJOR, input_dev->absbit);

    input_mt_init_slots(input_dev, MAX_CONTACTS);

    input_set_abs_params(input_dev,ABS_MT_POSITION_X, 0, SCREEN_MAX_X, 0, 0);
    input_set_abs_params(input_dev,ABS_MT_POSITION_Y, 0, SCREEN_MAX_Y, 0, 0);
    input_set_abs_params(input_dev,ABS_MT_TOUCH_MAJOR, 0, PRESS_MAX, 0, 0);
    input_set_abs_params(input_dev,ABS_MT_WIDTH_MAJOR, 0, 200, 0, 0);
    input_dev->name        = FT5X0X_NAME;
    input_register_device(input_dev);

    g_dev = ft5x0x_ts;

    i2c_set_clientdata(client, ft5x0x_ts);
    INIT_WORK(&ft5x0x_ts->pen_event_work, ft5x0x_ts_pen_irq_work);   //动态建立一个工作队列
    ft5x0x_ts->ts_workqueue = create_workqueue(FT5X0X_NAME);

    ft5x0x_ts->irq = gpio_to_irq(ft5x0x_ts->irq);

err0:
    msleep(200);
    fts_register_read(FT5X0X_REG_FIRMID, &reg_version,1);
    fts_register_read(FT5X0X_REG_REPORT_RATE, &reg_value,1);
    fts_register_read(FT5X0X_REG_THRES, &reg_value,1);
    fts_register_read(FT5X0X_REG_NOISE_MODE, &reg_value,1);

    //注册中断
    request_irq(ft5x0x_ts->irq, ft5x0x_ts_interrupt, IRQF_TRIGGER_FALLING, "ft5x0x_ts", ft5x0x_ts);
    disable_irq_nosync(g_dev->irq);
    //打开中断
    enable_irq(g_dev->irq);

    return 0;
}

当有按键按下时

static irqreturn_t ft5x0x_ts_interrupt(int irq, void *dev_id)
{
    struct ft5x0x_ts_dev *ft5x0x_ts = dev_id;
    del_timer(&ft5x0x_ts->timer);               //关闭内核定时器
    disable_irq_nosync(g_dev->irq);             //关中断
    queue_work(ft5x0x_ts->ts_workqueue, &ft5x0x_ts->pen_event_work); //把任务交给指定的工作队列
    return IRQ_HANDLED;
}

INIT_WORK(&ft5x0x_ts->pen_event_work, ft5x0x_ts_pen_irq_work);   //动态建立一个工作队列
进入工作队列处理函数:

static void ft5x0x_ts_pen_irq_work(struct work_struct *work)
{
    ft5x0x_read_data();
    ft5x0x_report_value();
    enable_irq(g_dev->irq);
}

static int ft5x0x_read_data(void)
{
    struct ft5x0x_ts_dev *data = i2c_get_clientdata(g_dev->client);
    struct ts_event *event = &data->event;
    u8 buf[61]= {0};
    ret = ft5x0x_i2c_rxdata(buf, 61);     //读取数据
    memset(event, ~0x00, sizeof(struct ts_event));
    event->touch_point = buf[2] & 0x0f;   //查看有几个手指按下
    if (event->touch_point == 0) {        //如果没有手指按下,直接返回
        return 0;
    }
    switch (event->touch_point) {     //最多只能看到5个手指
    case 5:                           //将手指的状态与坐标值记录下来
        event->point[4].status = (buf[0x1b] & 0xc0)>>6;
        event->point[4].id = (buf[0x1d] & 0xf0)>>4;
        event->point[4].x = ((s16)(buf[0x1b] & 0x07)<<8 | (s16)buf[0x1c]);
        event->point[4].y = (s16)(buf[0x1d] & 0x07)<<8 | (s16)buf[0x1e];
    case 4:
    case 3:
    case 2:
    case 1:
        event->point[0].status = (buf[0x03] & 0xc0)>>6;
        event->point[0].id = (buf[0x05] & 0xf0)>>4;
        event->point[0].x= (s16)(buf[0x03] & 0x07)<<8 | (s16)buf[0x04];
        event->point[0].y = (s16)(buf[0x05] & 0x07)<<8 | (s16)buf[0x06];
    default:
        return 0;
    }
}

static void ft5x0x_report_value(void)
{
    struct ft5x0x_ts_dev *data = i2c_get_clientdata(g_dev->client);
    struct ts_event *event = &data->event;
    int key_id = 0xff;
    down_table = 0;
    for(i=0; i<event->touch_point; i++)
    {
        event->point[i].x=event->point[i].x;
        input_mt_slot(data->input_dev, event->point[i].id);

        input_report_abs(data->input_dev, ABS_MT_TRACKING_ID, event->point[i].id);

        down_table |= 1 << event->point[i].id;
        input_report_abs(data->input_dev, ABS_MT_TOUCH_MAJOR, 100);
        input_report_abs(data->input_dev, ABS_MT_POSITION_X, event->point[i].x);
        input_report_abs(data->input_dev, ABS_MT_POSITION_Y, event->point[i].y);
        input_report_abs(data->input_dev, ABS_MT_WIDTH_MAJOR, 100);
    }

    for(i=0; i<MAX_CONTACTS; i++) {
        if( ( (~down_table) & 1<<i) && !(up_table & 1<<i) )
        {
            input_mt_slot(data->input_dev, i);
            input_report_abs(data->input_dev, ABS_MT_TRACKING_ID, -1);
        }
    }
    up_table = ~down_table;
    input_sync(data->input_dev);
}

关于内核定时器:
setup_timer(&ft5x0x_ts->timer, Touch_timer_release, (unsigned long)ft5x0x_ts);
data->timer.expires    = jiffies +8;
add_timer(&data->timer);
时间一到执行内核定时器处理函数

static void Touch_timer_release(unsigned long ft_ts_pdev)
{
   do_something();
}