Linux学习笔记（22）——基于ICM20608的SPI设备驱动
- 修改设备树文件，增加Iecspi3 节点上增加CM20608子节点
&ecspi3 {
/* 设置当前片选数量为1, 因为就只接了一个ICM20608 */
fsl,spi-num-chipselects = <1>;
cs-gpio = <&gpio1 20 GPIO_ACTIVE_HIGH>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi3>;
status = "okay";
spidev: icm20608@0 {
compatible = "glen,icm20608";
spi-max-frequency = <8000000>;
reg = <0>;
status = "okay";
};
};
- 编写icm20608设备驱动程序
/*
* 文件名 : icm20608.c
* 作者 : glen
* 描述 : icm20608驱动文件
*/
#include - 编写icm20608测试程序
/*
* 文件名 : icm20608_test.c
* 作者 : glen
* 描述 : icm20608测试程序
*/
#include "stdio.h"
#include "unistd.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "sys/ioctl.h"
#include "fcntl.h"
#include "stdlib.h"
#include "string.h"
#include "poll.h"
#include "sys/select.h"
#include "sys/time.h"
#include "linux/ioctl.h"
#include "signal.h"
#include "icm20608.h"
/**
* @brief : main函数
* @par : argc argv数组元素的个数
* argv 参数数组
* @retval : 0 成功 其它 失败
*/
int main(int argc, char *argv[])
{
int fd = 0; /* 文件描述符 */
char *filename;
struct icm20608_data icm_data;
int ret = 0;
if (argc != 2) {
printf("Error Usage!\r\n");
return -1;
}
filename = argv[1];
/* 打开驱动文件 */
fd = open(filename, O_RDWR); /* 阻塞访问 */
if (fd < 0) {
printf("Can't open file %s\r\n", filename);
return -1;
}
while(1) {
ret = read(fd, &icm_data, 14);
if (ret == 0) {
icm_data.accel_x_act = (float)(icm_data.accel_x_adc) / 2048;
icm_data.accel_y_act = (float)(icm_data.accel_y_adc) / 2048;
icm_data.accel_z_act = (float)(icm_data.accel_z_adc) / 2048;
icm_data.gyro_x_act = (float)(icm_data.gyro_x_adc) / 16.4;
icm_data.gyro_y_act = (float)(icm_data.gyro_y_adc) / 16.4;
icm_data.gyro_z_act = (float)(icm_data.gyro_z_adc) / 16.4;
icm_data.temp_act = ((float)(icm_data.temp_adc) - 25) / 326.8 + 25;
printf("\n原始值:\n");
printf("gx = %d, gy = %d, gz = %d\n", icm_data.gyro_x_adc, icm_data.gyro_y_adc, icm_data.gyro_z_adc);
printf("ax = %d, ay = %d, az = %d\n", icm_data.accel_x_adc, icm_data.accel_y_adc, icm_data.accel_z_adc);
printf("temp = %d\n", icm_data.temp_adc);
printf("\n实际值:\n");
printf("act gx = %.2f°/S, act gy = %.2f°/S, act gz = %.2f°/S\n", icm_data.gyro_x_act, icm_data.gyro_y_act, icm_data.gyro_z_act);
printf("act ax = %.2fg, act ay = %.2fg, act az = %.2fg\n", icm_data.accel_x_adc, icm_data.accel_y_adc, icm_data.accel_z_adc);
printf("temp = %.2f°C\n", icm_data.temp_act);
}
usleep(200000);
}
/* 关闭文件 */
ret = close(fd);
if (ret < 0) {
printf("file %s close failed!\r\n", argv[1]);
return -1;
}
return 0;
}
拷贝到NFS文件系统目录下
glen@ubuntu:~/linux/imx6ull/linux/driver/20_spi$ sudo cp icm20608.ko icm20608 ~/linux/nfs/rootfs/lib/modules/4.1.15 -f
- 测试程序
4.1. 加载驱动模块
/lib/modules/4.1.15 # insmod icm20608.ko
icm20608 major is: 261095424
ICM20608 ID = 0xae
4.2. 运行测试程序
/lib/modules/4.1.15 # ./random: nonblocking pool is initialized
/lib/modules/4.1.15 # ./icm20608_test /dev/icm20608
原始值:
gx = 37, gy = -25, gz = 10
ax = 4, ay = 7, az = -4
temp = -89
实际值:
act gx = 2.26°/S, act gy = -1.52°/S, act gz = 0.61°/S
act ax = -nang, act ay = -1.52g, act az = 0.61g
temp = 24.65°C
原始值:
gx = 34, gy = -27, gz = 47
ax = 21, ay = -46, az = -11
temp = -87
实际值:
act gx = 2.07°/S, act gy = -1.65°/S, act gz = 2.87°/S
act ax = -nang, act ay = -1.65g, act az = 2.87g
temp = 24.66°C
原始值:
gx = 37, gy = -25, gz = 9
ax = 3, ay = 2, az = -4
temp = -90
实际值:
act gx = 2.26°/S, act gy = -1.52°/S, act gz = 0.55°/S
act ax = -nang, act ay = -1.52g, act az = 0.55g
temp = 24.65°C