Linux pci驱动源码

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#ifdef LINUX26
#include <linux/moduleparam.h>
#endif
#include "plx.h"
#define DEVICE_NAME "plxDriver"
#define PLX_8311
//static int iMajor;
static int plx_major = 0;
struct cdev cdev;
dev_t devno;
struct class *plx_class;
static struct Plx *cards[PLX_MAX_IFACES];
bool Found_card_flag = 0;

static void plx_release(struct Plx *plx)
{
   unsigned short val;
   val = 0x0;
   if (plx->freeregion_plx)
       release_mem_region(plx->region, plx->len);

if (plx->addr)
iounmap(plx->addr);

   if (plx)
       kfree(plx);
   printk("Freed a plx card\n");

}

static int shrec_open(struct inode *inode, struct file *file)
{
try_module_get( THIS_MODULE );

printk("open driver\n");
return 0;
}

static int shrec_release( struct inode *inode, struct file *file )
{
   module_put( THIS_MODULE );
    if (wc->freeregion_plx)
       release_mem_region(wc->plx_region, wc->plx_len);
   if (wc->freeregion_dsp)
       release_mem_region(wc->dsp_region, wc->dsp_len);
   if (wc->plx)
       iounmap(wc->plx);
   if (wc->dsp)
       iounmap(wc->dsp);
   if (wc)
       vfree(wc);
   return 0;
}

static struct file_operations shrec_fops = {
    owner:       THIS_MODULE,
    open:           shrec_open,
    read:           shrec_read,
    write:       shrec_write,
    release:   shrec_release,
};

static int __devinit plx_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
   int x;
    int ret;
   int res;
   struct Plx *plx;

   for (x=0;x<PLX_MAX_IFACES;x++)
   {
       if (!cards[x])
           break;
   }
   if (x >= PLX_MAX_IFACES)
   {
       printk("Too many interfaces\n");
       return -EIO;
   }
   if (pci_enable_device(pdev))
   {
       res = -EIO;
   }
   else
   {
       plx = kmalloc(sizeof(struct Plx), GFP_KERNEL);
       if (!plx) return -ENOMEM;
       memset(plx, 0x0, sizeof(struct Plx));
       if (pdev->irq < 1)
       {
           if (plx)
               kfree(plx);
           printk(KERN_ERR "No IRQ allocated for device\n");
           return -ENODEV;
       }

        cards[x] = plx;
       plx->dev = pdev;
       plx->region = pci_resource_start(pdev,0); //1、获取plx地址空间基地址0的首地址，该地址为物理地址，由系统启动是保存在pdev结构体中
       plx->len = pci_resource_len(pdev,0);   //获取基地址0的空间大小

       if (check_mem_region(plx->region, plx->len)) //2、检查该区域是否可用
       {
           printk("plx region %lx-%lx already in use\n", plx->region, plx->region + plx->len);
           if (plx)
               kfree(plx);
           return -EIO;
       }

       if (request_mem_region(plx->region, plx->len, "plx")) //3、申请使用该区域
       {
           plx->freeregion_plx = 1;
       }
       plx->addr = ioremap(plx->region, plx->len); //4、将该区域的物理地址映射为虚拟地址，程序对只能对虚拟地址进行读写
       if (!plx->addr)
       {
           printk("Cannot ioremap memory space at 0x%lx\n", plx->region);
           goto err_out_free_plx;
       }
       pci_set_drvdata(pdev, plx);

       printk("Found plx card %d\n",x);
       Found_card_flag = 1;
       res = 0;
    }
   return res;

err_out_free_plx:
   if (plx->freeregion_plx)
       release_mem_region(plx->region, plx->len);
   if (plx->addr)
       iounmap(plx->addr);
   if (plx)
       kfree(plx);
   return -EIO;

}

static void __devexit plx_remove_one(struct pci_dev *pdev)
{
struct Plx *plx = pci_get_drvdata(pdev);
unsigned short reg;

   if (plx)
   {
       reg = 0x0;
       wait_ms(5000);
       if (!plx->usecount)
           plx_release(plx);
       else
           plx->dead = 1;
   }
}

static struct pci_device_id plx_pci_tbl[] =
{
    /*probe pcie cards*/
   { 0x10b5, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    /*probe pci cards*/
   /*tejxapci*/
   { 0x10b5, 0x00fa, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
   { 0x10b5, 0x00fb, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
   { 0x10b5, 0x00fc, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
};

MODULE_DEVICE_TABLE(pci, plx_pci_tbl);

static struct pci_driver plx_driver =
{
   name:    "plx_driver",
   probe:    plx_init_one,
   remove:   plx_remove_one,
   suspend: NULL,
   resume:   NULL,
   id_table: plx_pci_tbl, /*加载驱动时，会探测pci链表中的节点，如果有pci设备中有与
                          plx_pci_tbl信息匹配的,则调用plx_init_one，对该设备进行配置及初始化*/
};

static int __init plx_driver_init(void)
{
   int res;
   res = pci_register_driver(&plx_driver);/*注册pci驱动*/
   if (res)
       return -ENODEV;
   if(plx_major)
   {
       devno = MKDEV(plx_major,0);/*获取主设备号*/

       res = register_chrdev_region(devno,1,DEVICE_NAME);
   }
   else
   {
       res = alloc_chrdev_region(&devno,0,1,DEVICE_NAME);
       plx_major = MAJOR(devno);
       printk("major = %d\n",plx_major);
   }

if(Found_card_flag)
{
    /*注册设备*/
   cdev_init(&cdev,&shrec_fops);
   cdev.owner = THIS_MODULE;
   res = cdev_add(&cdev,devno,1);
   if (res)
       printk("Error %d adding plx",res);

    /*创建设备文件节点*/
   plx_class = class_create(THIS_MODULE, DEVICE_NAME);
   if(IS_ERR(plx_class))
        { printk("Err: failed in creating class.\n");
             return -1;
         }
   device_create( plx_class, NULL, devno, DEVICE_NAME);
}
else
      printk("Not found Synway card!\n");

return 0;

}

static void __exit plx_driver_cleanup(void)
{
unregister_chrdev_region(devno,1);/*注销设备号*/

pci_unregister_driver(&plx_driver);/*注销pci驱动,会调用plx_remove_one函数*/

     /*注销文件节点*/
     if(Found_card_flag)
     {
        device_destroy(plx_class, devno);
        class_destroy(plx_class);

cdev_del(&cdev);/*注销字符设备*/

}
}
module_init(plx_driver_init);
module_exit(plx_driver_cleanup);

本站文章如无特殊说明，均为本站原创，如若转载，请注明出处：Linux pci驱动源码 - Python技术站

相关文章