求助ft5x06触摸屏源码不明白！！

z2500abc · 发表于 2020-3-25 23:15:29

static int edt_ft5x06_ts_readwrite(struct i2c_client *client,
   u16 wr_len, u8 *wr_buf,
   u16 rd_len, u8 *rd_buf)
{
struct i2c_msg wrmsg[2];
int i = 0;
int ret;
if (wr_len) {
  wrmsg.addr  = client->addr;
  wrmsg.flags = 0;
  wrmsg.len = wr_len;
  wrmsg.buf = wr_buf;
  i++;
}                     /*此处有疑问，第一个if语句执行完以后，wr_len 会自动减1嘛？*/
if (rd_len) {
  wrmsg.addr  = client->addr;
  wrmsg.flags = I2C_M_RD;
  wrmsg.len = rd_len;
  wrmsg.buf = rd_buf;
  i++;
}
ret = i2c_transfer(client->adapter, wrmsg, i);
if (ret < 0)
  return ret;
if (ret != i)
  return -EIO;
return 0;
}