Modify the screen TP driver

Modify the copied TP driver file

Modify the registered semaphore name

static int rt_tp_device_init(void)
{
    ...
    driver.isr_sem = rt_sem_create("gt911", 0, RT_IPC_FLAG_FIFO); //修改这个信号量名称为gt911
    rt_touch_drivers_register(&driver);
    return 0;
}

Modify the communication interface in the probe function

The Probe function generally performs several tasks:

1. Open the communication interface (such as I2C), and configure the interface frequency, timeout, and so on

2. Read a register and return the status according to whether the TP is present (for example, a TP status register). If compatibility with multiple TP drivers is not required, you can directly return RT_EOK (TP present))

Modify the Init function

The driver initialization function mainly does the following:

1. Reset TP

2. Configure the trigger condition of the TP interrupt GPIO, and register the interrupt callback handler

It is recommended to use the following interfaces and not use rt_pin_xxx interfaces:

• rt_touch_irq_pin_attach(PIN_IRQ_MODE_FALLING, irq_handler, NULL); TP interrupt registration

• rt_touch_irq_pin_enable(v) Interrupt enable and disable

Modify the interrupt callback function

The interrupt callback generally does not need to be modified. It usually performs the following:

1. Disable the GPIO interrupt

2. Release the semaphore (triggering the upper layer to call read_point to read data)

Modify the callback function for reading TP data

The implementation of the TP data read function is generally:

1. Read TP data through the communication interface (such as I2C)

2. After reading is complete, enable the TP interrupt (to trigger the next read)

3. Transfer and return the data. Note: the return value must not always be RT_EOK, otherwise it will fall into an infinite loop. If touch data reading is complete, return RT_EEMPTY.

static rt_err_t read_point(touch_msg_t p_msg)
{
    gt911_piont_t i2c_result;

    i2c_read_(0x8150, 6, &i2c_result); //通过I2C  读取TP数据
    
    rt_touch_irq_pin_enable(1); //使能TP中断

    /*返回TP数据到p_msg*/
    p_msg->event = i2c_result.status ? TOUCH_EVENT_DOWN : TOUCH_EVENT_UP;
    p_msg->x = i2c_result.x;
    p_msg->y = i2c_result.y;

    return RT_EEMPTY; //RT_EEMPTY - 代表数据已经读完。
}