通过驱动开发给pcb板子点灯。
u-boot已经提前移植到了emmc中。
灯也是一种字符型设备。
编程流程需要先注册设备，然后创建结点，然后操作电灯相关寄存器
应用层直接调用read write来打开字符设备进行操作。
这样写会造成无法处理内核页面请求的虚拟地址内部错误，没找到解决方法
head.h
#ifndef __LED_H__
#define __LED_H__
typedef struct {
volatile unsigned int TZCR; // 0x000
volatile unsigned int res1[2]; // 0x004-0x008
volatile unsigned int OCENSETR; // 0x00C
volatile unsigned int OCENCLRR; // 0x010
volatile unsigned int res2[1]; // 0x014
volatile unsigned int HSICFGR; // 0x018
volatile unsigned int CSICFGR; // 0x01C
volatile unsigned int MPCKSELR; // 0x020
volatile unsigned int ASSCKSELR; // 0x024
volatile unsigned int PCK12SELR; // 0x028
volatile unsigned int MPCKDIVR; // 0x02C
volatile unsigned int AXIDIVR; // 0x030
volatile unsigned int res3[2];
volatile unsigned int APB4DIVR; // 0x03C
volatile unsigned int APB5DIVR; // 0x040
volatile unsigned int RTCDIVR; // 0x044
volatile unsigned int MSSCKSELR; // 0x048
volatile unsigned int res4[13];
volatile unsigned int PLL1CR; // 0x080
volatile unsigned int PLL1CFGR1; // 0x084
volatile unsigned int PLL1CFGR2; // 0x088
volatile unsigned int PLL1FRACR; // 0x08C
volatile unsigned int PLL1CSGR; // 0x090
volatile unsigned int PLL2CR; // 0x094
volatile unsigned int PLL2CFGR1; // 0x098
volatile unsigned int PLL2CFGR2; // 0x09C
volatile unsigned int PLL2FRACR; // 0x0A0
volatile unsigned int PLL2CSGR; // 0x0A4
volatile unsigned int res5[6];
volatile unsigned int I2C46CKSELR; // 0x0C0
volatile unsigned int SPI6CKSELR; // 0x0C4
volatile unsigned int UART1CKSELR; // 0x0C8
volatile unsigned int RNG1CKSELR; // 0x0CC
volatile unsigned int CPERCKSELR; // 0x0D0
volatile unsigned int STGENCKSELR; // 0x0D4
volatile unsigned int DDRITFCR; // 0x0D8
volatile unsigned int res6[9];
volatile unsigned int MP_BOOTCR; // 0x100
volatile unsigned int MP_SREQSETR; // 0x104
volatile unsigned int MP_SREQCLRR; // 0x108
volatile unsigned int MP_GCR; // 0x10C
volatile unsigned int MP_APRSTCR; // 0x110
volatile unsigned int MP_APRSTSR; // 0x114
volatile unsigned int res7[10];
volatile unsigned int BDCR; // 0x140
volatile unsigned int RDLSICR; // 0x144
volatile unsigned int res8[14];
volatile unsigned int APB4RSTSETR; // 0x180
volatile unsigned int APB4RSTCLRR; // 0x184
volatile unsigned int APB5RSTSETR; // 0x188
volatile unsigned int APB5RSTCLRR; // 0x18C
volatile unsigned int AHB5RSTSETR; // 0x190
volatile unsigned int AHB5RSTCLRR; // 0x194
volatile unsigned int AHB6RSTSETR; // 0x198
volatile unsigned int AHB6RSTCLRR; // 0x19C
volatile unsigned int TZAHB6RSTSELR;// 0x1A0
volatile unsigned int TZAHB6RSTCLRR;// 0x1A4
volatile unsigned int res9[22];
volatile unsigned int MP_APB4ENSETR;// 0x200
volatile unsigned int MP_APB4ENCLRR;// 0x204
volatile unsigned int MP_APB5ENSETR;// 0x208
volatile unsigned int MP_APB5ENCLRR;// 0x20C
volatile unsigned int MP_AHB5ENSETR;// 0x210
volatile unsigned int MP_AHB5ENCLRR;// 0x214
volatile unsigned int MP_AHB6ENSETR;// 0x218
volatile unsigned int MP_AHB6ENCLRR;// 0x21C
volatile unsigned int MP_TZAHB6ENSELR;// 0x220
volatile unsigned int MP_TZAHB6ENCLRR;// 0x224
volatile unsigned int res10[22];
volatile unsigned int MC_APB4ENSETR; // 0x280
volatile unsigned int MC_APB4ENCLRR; // 0x284
volatile unsigned int MC_APB5ENSETR; // 0x288
volatile unsigned int MC_APB5ENCLRR; // 0x28C
volatile unsigned int MC_AHB5ENSETR; // 0x290
volatile unsigned int MC_AHB5ENCLRR; // 0x294
volatile unsigned int MC_AHB6ENSETR; // 0x298
volatile unsigned int MC_AHB6ENCLRR; // 0x29C
volatile unsigned int res11[24];
volatile unsigned int MP_APB4LPENSETR; // 0x300
volatile unsigned int MP_APB4LPENCLRR; // 0x304
volatile unsigned int MP_APB5LPENSETR; // 0x308
volatile unsigned int MP_APB5LPENCLRR; // 0x30C
volatile unsigned int MP_AHB5LPENSETR; // 0x310
volatile unsigned int MP_AHB5LPENCLRR; // 0x314
volatile unsigned int MP_AHB6LPENSETR; // 0x318
volatile unsigned int MP_AHB6LPENCLRR; // 0x31C
volatile unsigned int MP_TZAHB6LPENSETR; // 0x320
volatile unsigned int MP_TZAHB6LPENCLRR; // 0x324
volatile unsigned int res12[22];
volatile unsigned int MC_APB4LPENSETR; // 0x380
volatile unsigned int MC_APB4LPENCLRR; // 0x384
volatile unsigned int MC_APB5LPENSETR; // 0x388
volatile unsigned int MC_APB5LPENCLRR; // 0x38C
volatile unsigned int MC_AHB5LPENSETR; // 0x390
volatile unsigned int MC_AHB5LPENCLRR; // 0x394
volatile unsigned int MC_AHB6LPENSETR; // 0x398
volatile unsigned int MC_AHB6LPENCLRR; // 0x39C
volatile unsigned int res13[24];
volatile unsigned int BR_RSTSCLRR; // 0x400
volatile unsigned int MP_GRSTCSETR; // 0x404
volatile unsigned int MP_RSTSR; // 0x408
volatile unsigned int MP_IWDGFZSETR; // 0x40C
volatile unsigned int MP_IWDGFZCLRR; // 0x410
volatile unsigned int MP_CIER; // 0x414
volatile unsigned int MP_CIFR; // 0x418
volatile unsigned int PWRLPDLYCR; // 0x41C
volatile unsigned int MP_RSTSS; // 0x420
volatile unsigned int res14[247];
volatile unsigned int MCO1CFGR; // 0x800
volatile unsigned int MCO2CFGR; // 0x804
volatile unsigned int OCRDYR; // 0x808
volatile unsigned int DBGCFGR; // 0x80C
volatile unsigned int res15[4];
volatile unsigned int RCK3SELR; // 0x820
volatile unsigned int RCK4SELR; // 0x824
volatile unsigned int TIMG1PRER; // 0x828
volatile unsigned int TIMG2PRER; // 0x82C
volatile unsigned int MCUDIVR; // 0x830
volatile unsigned int APB1DIVR; // 0x834
volatile unsigned int APB2DIVR; // 0x838
volatile unsigned int APB3DIVR; // 0x83C
volatile unsigned int res16[16];
volatile unsigned int PLL3CR; // 0x880
volatile unsigned int PLL3CFGR1; // 0x884
volatile unsigned int PLL3CFGR2; // 0x888
volatile unsigned int PLL3FRACR; // 0x88C
volatile unsigned int PLL3CSGR; // 0x890
volatile unsigned int PLL4CR; // 0x894
volatile unsigned int PLL4CFGR1; // 0x898
volatile unsigned int PLL4CFGR2; // 0x89C
volatile unsigned int PLL4FRACR; // 0x8A0
volatile unsigned int PLL4CSGR; // 0x8A4
volatile unsigned int res17[6];
volatile unsigned int I2C12CKSELR; // 0x8C0
volatile unsigned int I2C35CKSELR; // 0x8C4
volatile unsigned int SAI1CKSELR; // 0x8C8
volatile unsigned int SAI2CKSELR; // 0x8CC
volatile unsigned int SAI3CKSELR; // 0x8D0
volatile unsigned int SAI4CKSELR; // 0x8D4
volatile unsigned int SPI2S1CKSELR; // 0x8D8
volatile unsigned int SPI2S23CKSELR; // 0x8DC
volatile unsigned int SPI45CKSELR; // 0x8E0
volatile unsigned int UART6CKSELR; // 0x8E4
volatile unsigned int UART24CKSELR; // 0x8E8
volatile unsigned int UART35CKSELR; // 0x8EC
volatile unsigned int UART78CKSELR; // 0x8F0
volatile unsigned int SDMMC12CKSELR; // 0x8F4
volatile unsigned int SDMMC3CKSELR; // 0x8F8
volatile unsigned int ETHCKSELR; // 0x8FC
volatile unsigned int QSPICKSELR; // 0x900
volatile unsigned int FMCCKSELR; // 0x904
volatile unsigned int res18[1];
volatile unsigned int FDCANCKSELR; // 0x90C
volatile unsigned int res19[1];
volatile unsigned int SPDIFCKSELR; // 0x914
volatile unsigned int CECCKSELR; // 0x918
volatile unsigned int USBCKSELR; // 0x91C
volatile unsigned int RNG2CKSELR; // 0x920
volatile unsigned int DSICKSELR; // 0x924
volatile unsigned int ADCCKSELR; // 0x928
volatile unsigned int LPTIM45CKSELR; // 0x92C
volatile unsigned int LPTIM23CKSELR; // 0x930
volatile unsigned int LPTIM1CKSELR; // 0x934
volatile unsigned int res20[18];
volatile unsigned int APB1RSTSETR; // 0x980
volatile unsigned int APB1RSTCLRR; // 0x984
volatile unsigned int APB2RSTSETR; // 0x988
volatile unsigned int APB2RSTCLRR; // 0x98C
volatile unsigned int APB3RSTSETR; // 0x990
volatile unsigned int APB3RSTCLRR; // 0x994
volatile unsigned int AHB2RSTSETR; // 0x998
volatile unsigned int AHB2RSTCLRR; // 0x99C
volatile unsigned int AHB3RSTSETR; // 0x9A0
volatile unsigned int AHB3RSTCLRR; // 0x9A4
volatile unsigned int AHB4RSTSETR; // 0x9A8
volatile unsigned int AHB4RSTCLRR; // 0x9AC
volatile unsigned int res21[20];
volatile unsigned int MP_APB1ENSETR; // 0xA00
volatile unsigned int MP_APB1ENCLRR; // 0xA04
volatile unsigned int MP_APB2ENSETR; // 0xA08
volatile unsigned int MP_APB2ENCLRR; // 0xA0C
volatile unsigned int MP_APB3ENSETR; // 0xA10
volatile unsigned int MP_APB3ENCLRR; // 0xA14
volatile unsigned int MP_AHB2ENSETR; // 0xA18
volatile unsigned int MP_AHB2ENCLRR; // 0xA1C
volatile unsigned int MP_AHB3ENSETR; // 0xA20
volatile unsigned int MP_AHB3ENCLRR; // 0xA24
volatile unsigned int MP_AHB4ENSETR; // 0xA28
volatile unsigned int MP_AHB4ENCLRR; // 0xA2C
volatile unsigned int res22[2];
volatile unsigned int MP_MLAHBENSETR; // 0xA38
volatile unsigned int MP_MLAHBENCLRR; // 0xA3C
volatile unsigned int res23[16];
volatile unsigned int MC_APB1ENSETR; // 0xA80
volatile unsigned int MC_APB1ENCLRR; // 0xA84
volatile unsigned int MC_APB2ENSETR; // 0xA88
volatile unsigned int MC_APB2ENCLRR; // 0xA8C
volatile unsigned int MC_APB3ENSETR; // 0xA90
volatile unsigned int MC_APB3ENCLRR; // 0xA94
volatile unsigned int MC_AHB2ENSETR; // 0xA98
volatile unsigned int MC_AHB2ENCLRR; // 0xA9C
volatile unsigned int MC_AHB3ENSETR; // 0xAA0
volatile unsigned int MC_AHB3ENCLRR; // 0xAA4
volatile unsigned int MC_AHB4ENSETR; // 0xAA8
volatile unsigned int MC_AHB4ENCLRR; // 0xAAC
volatile unsigned int MC_AXIMENSETR; // 0xAB0
volatile unsigned int MC_AXIMENCLRR; // 0xAB4
volatile unsigned int MC_MLAHBENSETR; // 0xAB8
volatile unsigned int MC_MLAHBENCLRR; // 0xABC
volatile unsigned int res24[16];
volatile unsigned int MP_APB1LPENSETR; // 0xB00
volatile unsigned int MP_APB1LPENCLRR; // 0xB04
volatile unsigned int MP_APB2LPENSETR; // 0xB08
volatile unsigned int MP_APB2LPENCLRR; // 0xB0C
volatile unsigned int MP_APB3LPENSETR; // 0xB10
volatile unsigned int MP_APB3LPENCLRR; // 0xB14
volatile unsigned int MP_AHB2LPENSETR; // 0xB18
volatile unsigned int MP_AHB2LPENCLRR; // 0xB1C
volatile unsigned int MP_AHB3LPENSETR; // 0xB20
volatile unsigned int MP_AHB3LPENCLRR; // 0xB24
volatile unsigned int MP_AHB4LPENSETR; // 0xB28
volatile unsigned int MP_AHB4LPENCLRR; // 0xB2C
volatile unsigned int MP_AXIMLPENSETR; // 0xB30
volatile unsigned int MP_AXIMLPENCLRR; // 0xB34
volatile unsigned int MP_MLAHBLPENSETR; // 0xB38
volatile unsigned int MP_MLAHBLPENCLRR; // 0xB3C
volatile unsigned int res25[16];
volatile unsigned int MC_APB1LPENSETR; // 0xB80
volatile unsigned int MC_APB1LPENCLRR; // 0xB84
volatile unsigned int MC_APB2LPENSETR; // 0xB88
volatile unsigned int MC_APB2LPENCLRR; // 0xB8C
volatile unsigned int MC_APB3LPENSETR; // 0xB90
volatile unsigned int MC_APB3LPENCLRR; // 0xB94
volatile unsigned int MC_AHB2LPENSETR; // 0xB98
volatile unsigned int MC_AHB2LPENCLRR; // 0xB9C
volatile unsigned int MC_AHB3LPENSETR; // 0xBA0
volatile unsigned int MC_AHB3LPENCLRR; // 0xBA4
volatile unsigned int MC_AHB4LPENSETR; // 0xBA8
volatile unsigned int MC_AHB4LPENCLRR; // 0xBAC
volatile unsigned int MC_AXIMLPENSETR; // 0xBB0
volatile unsigned int MC_AXIMLPENCLRR; // 0xBB4
volatile unsigned int MC_MLAHBLPENSETR; // 0xBB8
volatile unsigned int MC_MLAHBLPENCLRR; // 0xBBC
volatile unsigned int res26[16];
volatile unsigned int MC_RSTSCLRR; // 0xC00
volatile unsigned int res27[4];
volatile unsigned int MC_CIER; // 0xC14
volatile unsigned int MC_CIFR; // 0xC18
volatile unsigned int res28[246];
volatile unsigned int VERR; // 0xFF4
volatile unsigned int IDR; // 0xFF8
volatile unsigned int SIDR; // 0xFFC
}rcc_t;
#define RCC ((rcc_t *)0x50000000)
typedef struct {
volatile unsigned int MODER; // 0x00
volatile unsigned int OTYPER; // 0x04
volatile unsigned int OSPEEDR; // 0x08
volatile unsigned int PUPDR; // 0x0C
volatile unsigned int IDR; // 0x10
volatile unsigned int ODR; // 0x14
volatile unsigned int BSRR; // 0x18
volatile unsigned int LCKR; // 0x1C
volatile unsigned int AFRL; // 0x20
volatile unsigned int AFRH; // 0x24
volatile unsigned int BRR; // 0x28
volatile unsigned int res;
volatile unsigned int SECCFGR; // 0x30
}gpio_t;
#define GPIOA ((gpio_t *)0x50002000)
#define GPIOB ((gpio_t *)0x50003000)
#define GPIOC ((gpio_t *)0x50004000)
#define GPIOD ((gpio_t *)0x50005000)
#define GPIOE ((gpio_t *)0x50006000)
#define GPIOF ((gpio_t *)0x50007000)
#define GPIOG ((gpio_t *)0x50008000)
#define GPIOH ((gpio_t *)0x50009000)
#define GPIOI ((gpio_t *)0x5000A000)
#define GPIOJ ((gpio_t *)0x5000B000)
#define GPIOK ((gpio_t *)0x5000C000)
#define GPIOZ ((gpio_t *)0x54004000)
#endifmychrdev.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"
unsigned int major; //定义一个变量保存主设备号
char kbuf[128] = {0};//定义一个内核中的buffer
unsigned int *vir_gpioe_moder = NULL;
unsigned int *vir_gpioe_odr = NULL;
unsigned int *vir_gpiof_moder = NULL;
unsigned int *vir_gpiof_odr = NULL;
unsigned int *vir_rcc = NULL;
//封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
ssize_t mycdev_read(struct file *file, char __user *ubuf, size_t size, loff_t *lof)
{
int res;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
res = copy_to_user(ubuf, kbuf, size);
if(res != 0)
{
printk("copy_to_user failed\n");
return -EIO;
}
return 0;
}
ssize_t mycdev_write(struct file *file, const char __user *ubuf, size_t size, loff_t *lof)
{
int res;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
res = copy_from_user(kbuf, ubuf, size);
if(res != 0)
{
printk("copy_from_user failed\n");
return -EIO;
}
//LED1开灯
if(kbuf[0] == '1' && kbuf[1] == '1')
{
*vir_gpioe_odr |= 0x1 << 10;
}
//LED1关灯
if(kbuf[0] == '1' && kbuf[1] == '0')
{
*vir_gpioe_odr &= ~(0x1 << 10);
}
//LED2开灯
if(kbuf[0] == '2' && kbuf[1] == '1')
{
*vir_gpiof_odr |= 0x1 << 10;
}
//LED2关灯
if(kbuf[0] == '2' && kbuf[1] == '0')
{
*vir_gpiof_odr &= ~(0x1 << 10);
}
//LED3开灯
if(kbuf[0] == '3' && kbuf[1] == '1')
{
*vir_gpioe_odr |= 0x1 << 8;
}
//LED3关灯
if(kbuf[0] == '3' && kbuf[1] == '0')
{
*vir_gpioe_odr &= ~(0x1 << 8);
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
struct file_operations fops={
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
volatile int *tmp = NULL;
major = register_chrdev(0,"mychrdev",&fops);
if(major < 0)
{
printk("注册字符设备驱动失败\n");
return major;
}
printk("注册字符设备驱动成功\n");
//初始化几个寄存器,将物理地址映射到虚拟地址，以方便用户空间进行读写操作
tmp = &GPIOE->MODER;
vir_gpioe_moder = ioremap(*tmp,4);
if(vir_gpioe_moder == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
vir_gpiof_moder = ioremap(GPIOF->MODER,4);
if(vir_gpioe_moder == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
vir_gpioe_odr = ioremap(GPIOE->ODR,4);
if(vir_gpioe_odr == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
vir_gpiof_odr = ioremap(GPIOF->ODR,4);
if(vir_gpiof_odr == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
vir_rcc = ioremap(RCC->MP_AHB4ENSETR,4);
if(vir_rcc == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//初始化几个寄存器的值
//设置RCC_MP_AHB4ENSETR寄存器第4第5两个引脚为1，使能GPIOE,GPIOF
*vir_rcc |= (0b11 << 4);
//设置GPIOE_MODER第20-21位为01
*vir_gpioe_moder &= ~(0b11 << 20);
*vir_gpioe_moder |= (0b01 << 20);
//设置GPIOF_MODER第20-21位为01
*vir_gpiof_moder &= ~(0b11 << 20);
*vir_gpiof_moder |= (0b01 << 20);
//设置GPIOE_MODER第16-17位为01
*vir_gpioe_moder &= ~(0b11 << 16);
*vir_gpioe_moder |= (0b01 << 16);
//设置GPIOE_ODR第10位为0
*vir_gpioe_odr &= ~(0b1 << 10);
//设置GPIOF_ODR第10位为0
*vir_gpiof_odr &= ~(0b1 << 10);
//设置GPIOE_ODR第8位为0
*vir_gpiof_odr &= ~(0b1 << 8);
return 0;
}
static void __exit mycdev_exit(void)
{
printk("设备卸载\n");
unregister_chrdev(major,"mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");led.c
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
int main()
{
char buf[128] = {0};
fprintf(stdout,"调用open\n");
int fd = open("/dev/mychrdev",O_RDWR);
if( fd < 0)
{
perror("");
exit(-1);
}
while(1)
{
fprintf(stdout,"请输入开关选项：\n");
fgets(buf,sizeof(buf),stdin);
buf[strlen(buf) - 1] = '\0';
fprintf(stdout,"调用write\n");
write(fd,buf,sizeof(buf));
}
close(fd);
return 0;
}————————————————————————————————————
后来发现追了一下ioremap函数的参数。第一个参数应该是一个long类型的变量，变量中保存的应该是寄存器的物理地址信息。
所以一开始传参传入的是寄存器的值是不对的。
但又因为如果直接传入取地址的寄存器会造成指针类型和long类型的隐性强转，编译器会报错。
所以得先定义一个long类型的tmp变量，用来保存每一个寄存器的物理地址信息。通过tmp中的值再去映射到虚拟地址。
以下是改版的mychrdev.c文章来源：https://www.toymoban.com/news/detail-605426.html
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"
unsigned int major; //定义一个变量保存主设备号
char kbuf[128] = {0};//定义一个内核中的buffer
unsigned int *vir_gpioe_moder = NULL;
unsigned int *vir_gpioe_odr = NULL;
unsigned int *vir_gpiof_moder = NULL;
unsigned int *vir_gpiof_odr = NULL;
unsigned int *vir_rcc = NULL;
//封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
ssize_t mycdev_read(struct file *file, char __user *ubuf, size_t size, loff_t *lof)
{
int res;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
//如果用户请求的buffer不满足用户需求，最大限度的满足用户需求
if(size > sizeof(kbuf))
{
size = sizeof(kbuf);
}
res = copy_to_user(ubuf, kbuf, size);
if(res != 0)
{
printk("copy_to_user failed\n");
return -EIO;
}
return 0;
}
ssize_t mycdev_write(struct file *file, const char __user *ubuf, size_t size, loff_t *lof)
{
int res;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
//如果用户请求的buffer不满足用户需求，最大限度的满足用户需求
if(size > sizeof(kbuf))
{
size = sizeof(kbuf);
}
res = copy_from_user(kbuf, ubuf, size);
if(res != 0)
{
printk("copy_from_user failed\n");
return -EIO;
}
//LED1开灯
if(kbuf[0] == '1' && kbuf[1] == '1')
{
*vir_gpioe_odr |= 0x1 << 10;
}
//LED1关灯
if(kbuf[0] == '1' && kbuf[1] == '0')
{
*vir_gpioe_odr &= ~(0x1 << 10);
}
//LED2开灯
if(kbuf[0] == '2' && kbuf[1] == '1')
{
*vir_gpiof_odr |= 0x1 << 10;
}
//LED2关灯
if(kbuf[0] == '2' && kbuf[1] == '0')
{
*vir_gpiof_odr &= ~(0x1 << 10);
}
//LED3开灯
if(kbuf[0] == '3' && kbuf[1] == '1')
{
*vir_gpioe_odr |= 0x1 << 8;
}
//LED3关灯
if(kbuf[0] == '3' && kbuf[1] == '0')
{
*vir_gpioe_odr &= ~(0x1 << 8);
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
struct file_operations fops={
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
//定义一个long类型(匹配ioremap函数第一个参数)，用来保存每个寄存器的地址信息
volatile unsigned long tmp = 0;
major = register_chrdev(0,"mychrdev",&fops);
if(major < 0)
{
printk("注册字符设备驱动失败\n");
return major;
}
printk("注册字符设备驱动成功\n");
//初始化几个寄存器,将物理地址映射到虚拟地址，以方便用户空间进行读写操作
//将地址信息强转为long类型方便tmp保存
tmp = (long)&GPIOE->MODER;
//将寄存器的物理地址映射到虚拟地址并保存
vir_gpioe_moder = ioremap(tmp,4);
if(vir_gpioe_moder == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//将地址信息强转为long类型方便tmp保存
tmp = (long)&GPIOF->MODER;
//将寄存器的物理地址映射到虚拟地址并保存
vir_gpiof_moder = ioremap(tmp,4);
if(vir_gpioe_moder == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//将地址信息强转为long类型方便tmp保存
tmp = (long)&GPIOE->ODR;
//将寄存器的物理地址映射到虚拟地址并保存
vir_gpioe_odr = ioremap(tmp,4);
if(vir_gpioe_odr == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//将地址信息强转为long类型方便tmp保存
tmp = (long)&GPIOF->ODR;
//将寄存器的物理地址映射到虚拟地址并保存
vir_gpiof_odr = ioremap(tmp,4);
if(vir_gpiof_odr == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//将地址信息强转为long类型方便tmp保存
tmp = (long)&RCC->MP_AHB4ENSETR;
//将寄存器的物理地址映射到虚拟地址并保存
vir_rcc = ioremap(tmp,4);
if(vir_rcc == NULL)
{
printk("映射物理内存失败");
return -EFAULT;
}
//初始化几个寄存器的值
//设置RCC_MP_AHB4ENSETR寄存器第4第5两个引脚为1，使能GPIOE,GPIOF
*vir_rcc |= (0b11 << 4);
//设置GPIOE_MODER第20-21位为01
*vir_gpioe_moder &= ~(0b11 << 20);
*vir_gpioe_moder |= (0b01 << 20);
//设置GPIOF_MODER第20-21位为01
*vir_gpiof_moder &= ~(0b11 << 20);
*vir_gpiof_moder |= (0b01 << 20);
//设置GPIOE_MODER第16-17位为01
*vir_gpioe_moder &= ~(0b11 << 16);
*vir_gpioe_moder |= (0b01 << 16);
//设置GPIOE_ODR第10位为0
*vir_gpioe_odr &= ~(0b1 << 10);
//设置GPIOF_ODR第10位为0
*vir_gpiof_odr &= ~(0b1 << 10);
//设置GPIOE_ODR第8位为0
*vir_gpiof_odr &= ~(0b1 << 8);
return 0;
}
static void __exit mycdev_exit(void)
{
//取消物理内存映射
iounmap(vir_gpioe_moder);
iounmap(vir_gpiof_moder);
iounmap(vir_gpioe_odr);
iounmap(vir_gpiof_odr);
iounmap(vir_rcc);
printk("设备卸载\n");
unregister_chrdev(major,"mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");改进的led.c，增加了一点儿注释文章来源地址https://www.toymoban.com/news/detail-605426.html
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
int main()
{
char buf[128] = {0};
fprintf(stdout,"调用open\n");
int fd = open("/dev/mychrdev",O_RDWR);
if( fd < 0)
{
perror("");
exit(-1);
}
while(1)
{
fprintf(stdout,"请输入开关选项：\n");
fprintf(stdout,"先输入123控制led1,led2,led3,再紧跟输入1开灯,0关灯\n");
fprintf(stdout,"输入q来结束\n");
fgets(buf,sizeof(buf),stdin);
buf[strlen(buf) - 1] = '\0';
//如果输入的是q或Q，结束循环
if(buf[0] == 'q' || buf[0] == 'Q')
{
break;
}
fprintf(stdout,"调用write\n");
write(fd,buf,sizeof(buf));
}
close(fd);
return 0;
}到了这里，关于day2 驱动开发 c语言的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！
