linux系统下命令读写qspi
时间: 2023-11-21 18:06:34 浏览: 45
在 Linux 系统下,可以使用 spidev 驱动来实现对 QSPI 的读写。具体步骤如下:
1. 加载 spidev 驱动模块:
```
modprobe spidev
```
2. 打开 spidev 设备,设置 SPI 模式、速率等参数:
```c
int fd;
unsigned char mode = SPI_MODE_0;
unsigned char bits = 8;
unsigned int speed = 1000000;
fd = open("/dev/spidev0.0", O_RDWR);
if (fd < 0) {
perror("can't open device");
return -1;
}
if (ioctl(fd, SPI_IOC_WR_MODE, &mode) == -1) {
perror("can't set spi mode");
return -1;
}
if (ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits) == -1) {
perror("can't set bits per word");
return -1;
}
if (ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed) == -1) {
perror("can't set max speed hz");
return -1;
}
```
3. 发送 QSPI 命令,并读写数据:
```c
unsigned char tx_buf[4];
unsigned char rx_buf[4];
// 发送命令:读取 QSPI ID
tx_buf[0] = 0x9F;
tx_buf[1] = 0x00;
tx_buf[2] = 0x00;
tx_buf[3] = 0x00;
struct spi_ioc_transfer tr = {
.tx_buf = (unsigned long)tx_buf,
.rx_buf = (unsigned long)rx_buf,
.len = 4,
.delay_usecs = 0,
.speed_hz = speed,
.bits_per_word = bits,
};
if (ioctl(fd, SPI_IOC_MESSAGE(1), &tr) == -1) {
perror("can't send spi message");
return -1;
}
// 读取 QSPI ID 结果
unsigned int qspi_id = (rx_buf[1] << 16) | (rx_buf[2] << 8) | rx_buf[3];
```
4. 关闭 spidev 设备:
```c
close(fd);
```
需要注意的是,具体的 QSPI 命令格式和数据交换方式需要参考 QSPI 设备的数据手册。