trndrv.c

将pci设备模拟成字符设备的模板程序。目前主要实现了ioctl系统调用。

// trndrv.c - the framework of PCI card driver in LINUX.
// By ---- -- (XWorm) Dec. 11 2001
// [e-mail]
//
// This file is written as an example of CHAR-type driver in LINUX.
// It serves a PCI card. It is free to copy and distribute in non-commercial
 conditions.
// There is no warranty provided by the programmer. And no responsibility of
 programmer
// is available to the results of the programs.
#ifndef CONFIG_PCI
#define CONFIG_PCI
#endif
#ifndef CONFIG_PROC_FS
#define CONFIG_PROC_FS
#endif
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <asm/uaccess.h>
/*****************************************\
|*       IOCTL MACRO DEFINITIONS         *|
\*****************************************/
#define TRNDRV_IOC_MAGIC 'k'
#define TRNDRV_IOCREADCONFREGS _IOR(TRNDRV_IOC_MAGIC, 0, 0x40)
#define TRNDRV_IOCREADOPERREGS _IOR(TRNDRV_IOC_MAGIC, 1, 0x40)
#define TRNDRV_IOC_MAXNR 2
/*****************************************\
|*       IOCTL MACRO DEFINITIONS         *|
\*****************************************/
#define VENDORID 0x1234 // unsigned short for vendor id of the PCI card
#define DEVICEID 0x4321 // unsigned short for device id of the PCI card
/*****************************************\
|*          GLOBAL DEFINITIONS           *|
\*****************************************/
struct pci_dev *pdev = NULL;
int readconfregs(u8 *regs);
int readoperregs(u8 *regs);
/****************************************\
|*     Driver "trndrv.o"`s entries      *|
\****************************************/
loff_t trndrv_llseek(struct file *filp, loff_t off, int whence)
{
    loff_t newpos = -EINVAL;
    return newpos;
}
int trndrv_open(struct inode *inode, struct file *filp)
{
    return 0;
}
int trndrv_release(struct inode *inode, struct file *filp)
{
    return 0;
}
ssize_t trndrv_read(struct file *filp, char *buf, size_t count,
                loff_t *f_pos)
{
    return 0;
}
ssize_t trndrv_write(struct file *filp, const char *buf, size_t count,
                loff_t *f_pos)
{
    return 0;
}
int trndrv_ioctl(struct inode *inode, struct file *filp,
                 unsigned int cmd, unsigned long arg)
{
    u8 regs[256];
    int i;
    switch (cmd)
    {
    case TRNDRV_IOCREADCONFREGS:
        if (readconfregs(regs))
            return -PCIBIOS_BAD_REGISTER_NUMBER;
        for (i = 0; i < 256; i ++)
            put_user(regs[i], (u8 *)(arg + i));
        break;
    case TRNDRV_IOCREADOPERREGS:
        readoperregs(regs);
        break;
    default:
        return -EINVAL;
    }
    return 0;
}
struct file_operations trndrv_fops = {
    llseek:     trndrv_llseek,
    read:       trndrv_read,
    write:      trndrv_write,
    ioctl:      trndrv_ioctl,
    open:       trndrv_open,
    release:    trndrv_release,
};
/*****************************************\
|*        Self-defined Functions         *|
\*****************************************/
struct proc_dir_entry *create_proc_fops_entry(const char *name,
                          mode_t mode, struct proc_dir_entry *base,
                          void * data)
{
    struct proc_dir_entry *result = create_proc_entry(name, mode, base);
    if (result)
    {
        result->proc_fops = &trndrv_fops;
        result->data = data;
    }
    return result;
}
int readconfregs(u8 *regs)
{
    int result;
    int i;
    for (i = 0; i < 256; i ++)
    {
        result = pci_read_config_byte(pdev, i, regs + i);
        if (result)
        {
            printk(KERN_EMERG "reading config regs error\n");
            return result;
        }
    }
    return 0;
}
int readoperregs(u8 *regs)
{
    return 0;
}
void cleanup_module(void)
{
    remove_proc_entry("trndrv", 0);
}
int init_module(void)
{
    create_proc_fops_entry("trndrv", 0, NULL, NULL);
    pdev = pci_find_device(VENDORID, DEVICEID, NULL);
    if (pdev == NULL)
    {
        printk(KERN_EMERG "no pci card specified\n");
        return -PCIBIOS_DEVICE_NOT_FOUND;
    }
    return 0;
}