driver/2-led/led.c

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#include <asm/io.h>
/***************************************************************
Copyright © ALIENTEK Co., Ltd. 1998-2029. All rights reserved.
文件名		: chrdevbase.c
作者	  	: 正点原子
版本	   	: V1.0
描述	   	: chrdevbase驱动文件。
其他	   	: 无
论坛 	   	: www.openedv.com
日志	   	: 初版V1.0 2020/12/26 正点原子创建
***************************************************************/
#define major_dev_id 80
#define dev_name "led"

#define PERIPH_BASE (0x40000000)
#define MPU_AHB4_PERIPH_BASE (PERIPH_BASE + 0x10000000)
#define RCC_BASE (MPU_AHB4_PERIPH_BASE + 0x0000)
#define RCC_MP_AHB4ENSETR (RCC_BASE + 0XA28)
#define GPIOI_BASE (MPU_AHB4_PERIPH_BASE + 0xA000)
#define GPIOI_MODER (GPIOI_BASE + 0x0000)
#define GPIOI_OTYPER (GPIOI_BASE + 0x0004)
#define GPIOI_OSPEEDR (GPIOI_BASE + 0x0008)
#define GPIOI_PUPDR (GPIOI_BASE + 0x000C)
#define GPIOI_BSRR (GPIOI_BASE + 0x0018)
/* 映射后的寄存器虚拟地址指针 */
static void __iomem *MPU_AHB4_PERIPH_RCC_PI;
static void __iomem *GPIOI_MODER_PI;
static void __iomem *GPIOI_OTYPER_PI;
static void __iomem *GPIOI_OSPEEDR_PI;
static void __iomem *GPIOI_PUPDR_PI;
static void __iomem *GPIOI_BSRR_PI;

char led_sta = '0';
static ssize_t tis_module_read(struct file *file, char __user *out, size_t size, loff_t *offt)
{
    int ret  = 0;
    ret = copy_to_user(out,&led_sta,1);
    return 0;
}
static ssize_t tis_module_write(struct file *file, const char __user *in, size_t size, loff_t *offt)
{
    int ret = 0;
    char sta;
    unsigned int val;
    ret = copy_from_user(&sta, in, 1);
    if (ret < 0)
    {
        return ret;
    }
    if (sta!='0'&&sta!='1')
    {
        printk("led module should input 0/1, your input is %c\n");
        return 0;
    }
    led_sta = sta;
    switch (sta)
    {
    case '1':
        val = readl(GPIOI_BSRR_PI);
        val |= (1 << 16);
        writel(val, GPIOI_BSRR_PI);
        break;
    case '0':
        val = readl(GPIOI_BSRR_PI);
        val |= (1 << 0);
        writel(val, GPIOI_BSRR_PI);
        break;
    default:
        break;
    }
    return 0;
}
static int tis_module_open(struct inode *inode, struct file *file)
{
    printk("%s: module open\n", dev_name);
    return 0;
}

static int tis_module_release(struct inode *inode, struct file *file)
{
    printk("%s: module release\n", dev_name);
    return 0;
}
static struct file_operations tis_module_f = {
    .owner = THIS_MODULE,
    .write = tis_module_write,
    .read = tis_module_read,
    .open = tis_module_open,
    .release = tis_module_release,
};
static void led_init(void)
{
    MPU_AHB4_PERIPH_RCC_PI = ioremap(RCC_MP_AHB4ENSETR, 4);
    GPIOI_MODER_PI = ioremap(GPIOI_MODER, 4);
    GPIOI_OTYPER_PI = ioremap(GPIOI_OTYPER, 4);
    GPIOI_OSPEEDR_PI = ioremap(GPIOI_OSPEEDR, 4);
    GPIOI_PUPDR_PI = ioremap(GPIOI_PUPDR, 4);
    GPIOI_BSRR_PI = ioremap(GPIOI_BSRR, 4);
    unsigned int val;
    /* 2、使能PI时钟 */
    val = readl(MPU_AHB4_PERIPH_RCC_PI);
    val &= ~(0X1 << 8); /* 清除以前的设置 */
    val |= (0X1 << 8);  /* 设置新值 */
    writel(val, MPU_AHB4_PERIPH_RCC_PI);

    /* 3、设置PI0通用的输出模式。*/
    val = readl(GPIOI_MODER_PI);
    val &= ~(0X3 << 0); /* bit0:1清零 */
    val |= (0X1 << 0);  /* bit0:1设置01 */
    writel(val, GPIOI_MODER_PI);

    /* 3、设置PI0为推挽模式。*/
    val = readl(GPIOI_OTYPER_PI);
    val &= ~(0X1 << 0); /* bit0清零，设置为上拉*/
    writel(val, GPIOI_OTYPER_PI);

    /* 4、设置PI0为高速。*/
    val = readl(GPIOI_OSPEEDR_PI);
    val &= ~(0X3 << 0); /* bit0:1 清零 */
    val |= (0x2 << 0);  /* bit0:1 设置为10*/
    writel(val, GPIOI_OSPEEDR_PI);

    /* 5、设置PI0为上拉。*/
    val = readl(GPIOI_PUPDR_PI);
    val &= ~(0X3 << 0); /* bit0:1 清零*/
    val |= (0x1 << 0);  /*bit0:1 设置为01*/
    writel(val, GPIOI_PUPDR_PI);

    /* 6、默认关闭LED */
    val = readl(GPIOI_BSRR_PI);
    val |= (0x1 << 0);
    writel(val, GPIOI_BSRR_PI);
    led_sta = '0';
}
static void led_io_unmap(void)
{
    iounmap(MPU_AHB4_PERIPH_RCC_PI);
    iounmap(GPIOI_MODER_PI);
    iounmap(GPIOI_OTYPER_PI);
    iounmap(GPIOI_OSPEEDR_PI);
    iounmap(GPIOI_PUPDR_PI);
    iounmap(GPIOI_BSRR_PI);
}

static int __init tis_module_init(void)
{
    register_chrdev(major_dev_id, dev_name, &tis_module_f);
    printk("%s init\n", dev_name);
    led_init();
    return 0;
}
static void __exit tis_module_exit(void)
{
    unregister_chrdev(major_dev_id, dev_name);
    led_io_unmap();
        printk("%s exit\n", dev_name);
}
module_init(tis_module_init);
module_exit(tis_module_exit);
MODULE_LICENSE("GPL v3.0");
MODULE_AUTHOR("Chenyf");