rt-thread-official/bsp/stm32f429-disco/drivers/drv_touch.c

/*
 * File      : drv_touch.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2018 RT-Thread Develop Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-10-03     xuzhuoyi     first implementation.
 */

#include "drv_touch.h"
#include "drivers/i2c.h"


#define TSC_I2C_ADDR    0x41            /* 7-bit I2C address                  */

static struct rt_i2c_bus_device *stmpe811_i2c_bus;


/**
  \fn          int32_t touch_readRegister (uint8_t reg, uint8_t *val)
  \brief       Read register value from Touchscreen controller
  \param[in]   reg    Register address
  \param[out]  val    Pointer where data will be read from register
  \returns
   - \b  0: function succeeded
   - \b -1: function failed
*/
static int32_t touch_read (uint8_t reg, uint8_t *val)
{
    struct rt_i2c_msg msgs[2];

    msgs[0].addr  = TSC_I2C_ADDR;
    msgs[0].flags = RT_I2C_WR;
    msgs[0].buf   = ®
    msgs[0].len   = 1;

    msgs[1].addr  = TSC_I2C_ADDR;
    msgs[1].flags = RT_I2C_RD;
    msgs[1].buf   = val;
    msgs[1].len   = 1;

    if (rt_i2c_transfer(stmpe811_i2c_bus, msgs, 2) == 2)
    {
        return RT_EOK;
    }
    else
    {
        return -RT_ERROR;
    }

}

/**
  \fn          int32_t touch_writeData (uint8_t reg, const uint8_t *val)
  \brief       Write value to Touchscreen controller register
  \param[in]   reg    Register address
  \param[in]   val    Pointer with data to write to register
  \returns
   - \b  0: function succeeded
   - \b -1: function failed
*/
static int32_t touch_write (uint8_t reg, uint8_t val)
{
    struct rt_i2c_msg msgs;
    rt_uint8_t buf[2] = {reg, val};

    msgs.addr  = TSC_I2C_ADDR;
    msgs.flags = RT_I2C_WR;
    msgs.buf   = buf;
    msgs.len   = 2;

    if (rt_i2c_transfer(stmpe811_i2c_bus, &msgs, 1) == 1)
    {
    return RT_EOK;
    }
    else
    {
    return -RT_ERROR;
    }

}


/**
  \fn          int32_t Touch_Initialize (void)
  \brief       Initialize touchscreen
  \returns
   - \b  0: function succeeded
   - \b -1: function failed
*/
int32_t Touch_Initialize (void)
{
    stmpe811_i2c_bus = rt_i2c_bus_device_find(STMPE811_I2CBUS_NAME);

//    ptrI2C->Initialize  (NULL);
//    ptrI2C->PowerControl(ARM_POWER_FULL);
//    ptrI2C->Control     (ARM_I2C_BUS_SPEED, ARM_I2C_BUS_SPEED_FAST);
//    ptrI2C->Control     (ARM_I2C_BUS_CLEAR, 0);

    touch_write(STMPE811_SYS_CTRL1,      0x02); /* Reset Touch-screen controller */
    rt_thread_mdelay(10);                              /* Wait 10ms                     */


    touch_write(STMPE811_SYS_CTRL2,      0x0C); /* Enable TSC and ADC            */
    touch_write(STMPE811_ADC_CTRL1,      0x68); /* Set sample time , 12-bit mode */
    rt_thread_mdelay(1);                               /* Wait 1ms                      */

    touch_write(STMPE811_ADC_CTRL2,      0x01); /* ADC frequency 3.25 MHz        */
    touch_write(STMPE811_TSC_CFG,        0xC2); /* Detect delay 10us,
                                                 Settle time 500us             */
    touch_write(STMPE811_FIFO_TH,        0x01); /* Threshold for FIFO            */
    touch_write(STMPE811_FIFO_STA,       0x01); /* FIFO reset                    */
    touch_write(STMPE811_FIFO_STA,       0x00); /* FIFO not reset                */
    touch_write(STMPE811_TSC_FRACTION_Z, 0x07); /* Fraction z                    */
    touch_write(STMPE811_TSC_I_DRIVE,    0x01); /* Drive 50 mA typical           */
    touch_write(STMPE811_GPIO_AF,        0x00); /* Pins are used for touchscreen */
    touch_write(STMPE811_TSC_CTRL,       0x01); /* Enable TSC                    */

    return 0;
}

/**
  \fn          int32_t Touch_Uninitialize (void)
  \brief       De-initialize touchscreen
  \returns
   - \b  0: function succeeded
   - \b -1: function failed
*/
int32_t Touch_Uninitialize (void) {
  touch_write(STMPE811_SYS_CTRL1, 0x02);  /* Reset Touch-screen controller    */
  return 0;
}

/**
  \fn          int32_t Touch_GetState (TOUCH_STATE *pState)
  \brief       Get touchscreen state
  \param[out]  pState  pointer to TOUCH_STATE structure
  \returns
   - \b  0: function succeeded
   - \b -1: function failed
*/
int32_t Touch_GetState (struct touch_state *pState) {
    uint8_t val;
    uint8_t num;
    uint8_t xyz[4];
    int32_t res;
    uint8_t buf[4];
    struct rt_i2c_msg msgs;

    /* Read touch status */
    res = touch_read(STMPE811_TSC_CTRL, &val);
    if (res < 0) return -1;
    pState->pressed = (val & (1 << 7)) ? 1 : 0;
  
    if (pState->pressed)
    {
        val = STMPE811_TSC_DATA;

        /* If FIFO overflow, discard all samples except the last one */
        res = touch_read(STMPE811_FIFO_SIZE, &num);
        if (res < 0 || num == 0) return -1;

        while (num--)
        {
            msgs.addr  = TSC_I2C_ADDR;
            msgs.flags = RT_I2C_WR;
            msgs.buf   = buf;
            msgs.len   = 1;

            rt_i2c_transfer(stmpe811_i2c_bus, &msgs, 1);
          //ptrI2C->MasterTransmit (TSC_I2C_ADDR, &val, 1, true);
          //while (ptrI2C->GetStatus().busy);
            msgs.addr  = TSC_I2C_ADDR;
            msgs.flags = RT_I2C_RD;
            msgs.buf   = buf;
            msgs.len   = 4;
            rt_i2c_transfer(stmpe811_i2c_bus, &msgs, 1);
          //ptrI2C->MasterReceive (TSC_I2C_ADDR, xyz, 4, false);
          //while (ptrI2C->GetStatus().busy);
        }
        pState->x =  (int16_t)((xyz[0] << 4) | ((xyz[1] & 0xF0) >> 4));
        pState->y =  (int16_t) (xyz[2]       | ((xyz[1] & 0x0F) << 8));
    }
    else
    {
    /* Clear all data in FIFO */
        touch_write(STMPE811_FIFO_STA, 0x1);
        touch_write(STMPE811_FIFO_STA, 0x0);
    }

    return 0;
}