278 lines
7.0 KiB
C
278 lines
7.0 KiB
C
#include <linux/types.h>
|
||
#include <linux/kernel.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>
|
||
#include <linux/cdev.h>
|
||
|
||
#define ENCODER_CNT 1 /* 主设备号 */
|
||
#define ENCODER_NAME "encoder" /* 设备名字 */
|
||
|
||
#define ENCODER_CMD_FUNCTION_CLEAR 1
|
||
#define ENCODER_CMD_FUNCTION_VIRT_INPUT 2
|
||
|
||
#define ENCODER_CMD_INPUT_MODE_EXTERNEL 100
|
||
#define ENCODER_CMD_INPUT_MODE_INTERNEL 101
|
||
|
||
|
||
/*
|
||
* 相关寄存器地址定义
|
||
*/
|
||
#define ENCODER_REG_BASE 0x43C10000
|
||
#define ENCODER_REG_0_OFFSET 0x00000000
|
||
#define ENCODER_REG_1_OFFSET 0x00000004
|
||
#define ENCODER_REG_2_OFFSET 0x00000008
|
||
#define ENCODER_REG_3_OFFSET 0x0000000C
|
||
|
||
/* 映射后的寄存器虚拟地址指针 */
|
||
static void __iomem *encoder_reg_0_addr;
|
||
static void __iomem *encoder_reg_1_addr;
|
||
static void __iomem *encoder_reg_2_addr;
|
||
static void __iomem *encoder_reg_3_addr;
|
||
|
||
struct encoder_dev
|
||
{
|
||
dev_t devid; /* 设备号 */
|
||
struct cdev cdev; /* cdev */
|
||
struct class *class; /* 类 */
|
||
struct device *device; /* 设备 */
|
||
int major; /* 主设备号 */
|
||
int minor; /* 次设备号 */
|
||
};
|
||
|
||
typedef struct
|
||
{
|
||
u32 valve_divide_value;
|
||
u32 camera_divide_value;
|
||
} kernelbuf_typedef;
|
||
|
||
static struct encoder_dev encoder;
|
||
|
||
/*
|
||
* @description : 打开设备
|
||
* @param – inode : 传递给驱动的inode
|
||
* @param - filp : 设备文件，file结构体有个叫做private_data的成员变量
|
||
* 一般在open的时候将private_data指向设备结构体。
|
||
* @return : 0 成功;其他 失败
|
||
*/
|
||
static int encoder_open(struct inode *inode, struct file *filp)
|
||
{
|
||
return 0;
|
||
}
|
||
|
||
/*
|
||
* @description : 向设备写数据
|
||
* @param - filp : 设备文件，表示打开的文件描述符
|
||
* @param - buf : 要写给设备写入的数据
|
||
* @param - cnt : 要写入的数据长度
|
||
* @param - offt : 相对于文件首地址的偏移
|
||
* @return : 写入的字节数，如果为负值，表示写入失败
|
||
*/
|
||
static ssize_t encoder_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offt)
|
||
{
|
||
int ret;
|
||
|
||
u32 data;
|
||
kernelbuf_typedef kern_buf = {
|
||
.valve_divide_value = 0,
|
||
.camera_divide_value = 0,
|
||
};
|
||
if (cnt != sizeof(kern_buf))
|
||
{
|
||
printk(KERN_ERR "encoder write: cnt error, cnt=%d", cnt);
|
||
return -EFAULT;
|
||
}
|
||
ret = copy_from_user(&kern_buf, buf, cnt); // 得到应用层传递过来的数据
|
||
if (ret < 0)
|
||
{
|
||
printk(KERN_ERR "kernel write failed!\r\n");
|
||
return -EFAULT;
|
||
}
|
||
if (!(kern_buf.valve_divide_value || kern_buf.camera_divide_value))
|
||
return 0;
|
||
|
||
data = readl(encoder_reg_0_addr);
|
||
writel(data & ~(u32)(1 << 0), encoder_reg_0_addr);
|
||
|
||
if (kern_buf.valve_divide_value != 0)
|
||
writel(kern_buf.valve_divide_value, encoder_reg_1_addr);
|
||
if (kern_buf.camera_divide_value != 0)
|
||
writel(kern_buf.camera_divide_value, encoder_reg_2_addr);
|
||
|
||
writel(data | (u32)(1 << 0), encoder_reg_0_addr);
|
||
|
||
return cnt;
|
||
}
|
||
|
||
/*
|
||
* @description : 关闭/释放设备
|
||
* @param – filp : 要关闭的设备文件(文件描述符)
|
||
* @return : 0 成功;其他 失败
|
||
*/
|
||
static int encoder_release(struct inode *inode, struct file *filp)
|
||
{
|
||
return 0;
|
||
}
|
||
|
||
static long encoder_ioctl(struct file *fp, unsigned int cmd, unsigned long tmp)
|
||
{
|
||
u32 data, cmd_parsed;
|
||
if (_IOC_TYPE(cmd) != 'D' || _IOC_DIR(cmd) != _IOC_WRITE)
|
||
{
|
||
printk(KERN_ERR "IOC_TYPE or IOC_WRITE error: IOC_TYPE=%c, IOC_WRITE=%d\r\n", _IOC_TYPE(cmd), _IOC_DIR(cmd));
|
||
return -EINVAL;
|
||
}
|
||
cmd_parsed = _IOC_NR(cmd);
|
||
data = readl(encoder_reg_0_addr);
|
||
if (cmd_parsed == ENCODER_CMD_FUNCTION_CLEAR)
|
||
{
|
||
writel(data & ~(u32)(1 << 0), encoder_reg_0_addr);
|
||
writel(data | (u32)(1 << 0), encoder_reg_0_addr);
|
||
}
|
||
else if (cmd_parsed == ENCODER_CMD_INPUT_MODE_EXTERNEL)
|
||
{
|
||
writel(data & ~(u32)(1 << 1), encoder_reg_0_addr);
|
||
}
|
||
else if (cmd_parsed == ENCODER_CMD_INPUT_MODE_INTERNEL)
|
||
{
|
||
writel(data | (u32)(1 << 1), encoder_reg_0_addr);
|
||
}
|
||
else if (cmd_parsed == ENCODER_CMD_FUNCTION_VIRT_INPUT)
|
||
{
|
||
int i;
|
||
// 1. ENCODER_CMD_INPUT_MODE_INTERNEL
|
||
writel(data | (u32)(1 << 1), encoder_reg_0_addr);
|
||
// 2. Generate pluses
|
||
for (i = 0; i < tmp; i++)
|
||
{
|
||
writel(data & ~(u32)(1 << 2), encoder_reg_0_addr);
|
||
writel(data | (u32)(1 << 2), encoder_reg_0_addr);
|
||
}
|
||
// 3. Recover the original configuration
|
||
writel(data, encoder_reg_0_addr);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* 设备操作函数 */
|
||
static struct file_operations encoder_fops = {
|
||
.owner = THIS_MODULE,
|
||
.open = encoder_open,
|
||
.write = encoder_write,
|
||
.release = encoder_release,
|
||
.unlocked_ioctl = encoder_ioctl,
|
||
};
|
||
|
||
static int __init encoder_init(void)
|
||
{
|
||
int ret;
|
||
u32 data;
|
||
/* 寄存器地址映射 */
|
||
encoder_reg_0_addr = ioremap(ENCODER_REG_BASE + ENCODER_REG_0_OFFSET, 4);
|
||
encoder_reg_1_addr = ioremap(ENCODER_REG_BASE + ENCODER_REG_1_OFFSET, 4);
|
||
encoder_reg_2_addr = ioremap(ENCODER_REG_BASE + ENCODER_REG_2_OFFSET, 4);
|
||
encoder_reg_3_addr = ioremap(ENCODER_REG_BASE + ENCODER_REG_3_OFFSET, 4);
|
||
|
||
/* 注册字符设备驱动 */
|
||
//(1)创建设备号
|
||
if (encoder.major)
|
||
{
|
||
encoder.devid = MKDEV(encoder.major, 0);
|
||
ret = register_chrdev_region(encoder.devid, ENCODER_CNT, ENCODER_NAME);
|
||
if (ret)
|
||
goto FAIL_REGISTER_CHR_DEV;
|
||
}
|
||
else
|
||
{
|
||
ret = alloc_chrdev_region(&encoder.devid, 0, ENCODER_CNT, ENCODER_NAME);
|
||
if (ret)
|
||
goto FAIL_REGISTER_CHR_DEV;
|
||
encoder.major = MAJOR(encoder.devid);
|
||
encoder.minor = MINOR(encoder.devid);
|
||
}
|
||
|
||
//(2)初始化cdev
|
||
encoder.cdev.owner = THIS_MODULE;
|
||
cdev_init(&encoder.cdev, &encoder_fops);
|
||
|
||
//(3)添加cdev
|
||
ret = cdev_add(&encoder.cdev, encoder.devid, ENCODER_CNT);
|
||
if (ret)
|
||
goto FAIL_ADD_CDEV;
|
||
|
||
//(4)创建类
|
||
encoder.class = class_create(THIS_MODULE, ENCODER_NAME);
|
||
if (IS_ERR(encoder.class))
|
||
{
|
||
ret = PTR_ERR(encoder.class);
|
||
goto FAIL_CREATE_CLASS;
|
||
}
|
||
|
||
//(5)创建设备
|
||
encoder.device = device_create(encoder.class, NULL, encoder.devid, NULL, ENCODER_NAME);
|
||
if (IS_ERR(encoder.device))
|
||
{
|
||
ret = PTR_ERR(encoder.device);
|
||
goto FAIL_CREATE_DEV;
|
||
}
|
||
|
||
//默认分频系数1000
|
||
data = readl(encoder_reg_0_addr);
|
||
writel(data & ~(u32)(1 << 0), encoder_reg_0_addr);
|
||
writel(1000, encoder_reg_1_addr);
|
||
writel(1000, encoder_reg_2_addr);
|
||
writel(data | (u32)(1 << 0), encoder_reg_0_addr);
|
||
|
||
return 0;
|
||
|
||
FAIL_CREATE_DEV:
|
||
class_destroy(encoder.class);
|
||
|
||
FAIL_CREATE_CLASS:
|
||
cdev_del(&encoder.cdev);
|
||
|
||
FAIL_ADD_CDEV:
|
||
unregister_chrdev_region(encoder.devid, ENCODER_CNT);
|
||
|
||
FAIL_REGISTER_CHR_DEV:
|
||
iounmap(encoder_reg_0_addr);
|
||
iounmap(encoder_reg_1_addr);
|
||
iounmap(encoder_reg_2_addr);
|
||
iounmap(encoder_reg_3_addr);
|
||
|
||
return ret;
|
||
}
|
||
|
||
static void __exit encoder_exit(void)
|
||
{
|
||
//(1)注销设备
|
||
device_destroy(encoder.class, encoder.devid);
|
||
|
||
//(2)注销类
|
||
class_destroy(encoder.class);
|
||
|
||
//(3)删除cdev
|
||
cdev_del(&encoder.cdev);
|
||
|
||
//(4)注销设备号
|
||
unregister_chrdev_region(encoder.devid, ENCODER_CNT);
|
||
|
||
//(5)取消内存映射
|
||
iounmap(encoder_reg_0_addr);
|
||
iounmap(encoder_reg_1_addr);
|
||
iounmap(encoder_reg_2_addr);
|
||
iounmap(encoder_reg_3_addr);
|
||
}
|
||
|
||
/* 驱动模块入口和出口函数注册 */
|
||
module_init(encoder_init);
|
||
module_exit(encoder_exit);
|
||
MODULE_AUTHOR("DingKun");
|
||
MODULE_DESCRIPTION("driver for hardware encoder in the platform");
|
||
MODULE_LICENSE("GPL");
|