mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
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pci attempt. It probes!
This commit is contained in:
Ciro Santilli
264
kernel_module/pci.c
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264
kernel_module/pci.c
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@@ -0,0 +1,264 @@
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/*
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http://www.zarb.org/~trem/kernel/pci/pci-driver.c
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http://nairobi-embedded.org/linux_pci_device_driver.html
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/fs.h>
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#include <linux/cdev.h> /* cdev_ */
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#include <asm/uaccess.h> /* put_user */
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#define MAX_DEVICE 1
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#define DEVICE_NAME "virtual_pci"
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#define BAR_IO 2
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#define BAR_MEM 3
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MODULE_LICENSE("GPL");
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static struct pci_device_id pci_ids[] = {
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{ PCI_DEVICE(0x1234, 0x11e8), },
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{ 0, }
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};
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MODULE_DEVICE_TABLE(pci, pci_ids);
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static dev_t devno;
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static int major;
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struct pci_cdev {
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int minor;
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struct pci_dev *pci_dev;
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struct cdev *cdev;
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};
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static struct pci_cdev pci_cdev[MAX_DEVICE];
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static void pci_cdev_del(struct pci_cdev pci_cdev[], int size, struct pci_dev *pdev)
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{
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int i;
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for (i=0; i<size; i++) {
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if (pci_cdev[i].pci_dev == pdev) {
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pci_cdev[i].pci_dev = NULL;
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}
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}
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}
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static struct pci_dev *pci_cdev_search_pci_dev(struct pci_cdev pci_cdev[], int size, int minor)
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{
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int i;
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struct pci_dev *pdev = NULL;
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for (i=0; i<size; i++) {
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if (pci_cdev[i].minor == minor) {
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pdev = pci_cdev[i].pci_dev;
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break;
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}
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}
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return pdev;
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}
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static struct cdev *pci_cdev_search_cdev(struct pci_cdev pci_cdev[], int size, int minor)
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{
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int i;
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struct cdev *cdev = NULL;
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for (i=0; i<size; i++) {
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if (pci_cdev[i].minor == minor) {
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cdev = pci_cdev[i].cdev;
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break;
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}
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}
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return cdev;
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}
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/**
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* -1 => not found
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* others => found
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*/
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static int pci_cdev_search_minor(struct pci_cdev pci_cdev[],
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int size, struct pci_dev *pdev)
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{
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int i, minor = -1;
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for (i=0; i<size; i++) {
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if (pci_cdev[i].pci_dev == pdev) {
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minor = pci_cdev[i].minor;
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break;
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}
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}
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return minor;
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}
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static int pci_open(struct inode *inode, struct file *file)
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{
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int minor = iminor(inode);
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file->private_data = (void *)pci_cdev_search_pci_dev(pci_cdev, MAX_DEVICE, minor);
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return 0;
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}
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static ssize_t pci_read(struct file *file,
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char *buffer,
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size_t length,
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loff_t * offset)
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{
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int byte_read = 0;
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unsigned char value;
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struct pci_dev *pdev = (struct pci_dev *)file->private_data;
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unsigned long pci_io_addr = 0;
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pci_io_addr = pci_resource_start(pdev,BAR_IO);
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while (byte_read < length) {
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value = inb(pci_io_addr + 1);
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put_user(value, &buffer[byte_read]);
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byte_read++;
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}
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return byte_read;
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}
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static ssize_t pci_write(struct file *filp, const char *buffer, size_t len, loff_t * off) {
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int i;
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unsigned char value;
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struct pci_dev *pdev = (struct pci_dev *)filp->private_data;
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unsigned long pci_io_addr = 0;
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pci_io_addr = pci_resource_start(pdev,BAR_IO);
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for (i=0; i<len; i++) {
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value = (unsigned char)buffer[i];
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outb(pci_io_addr+2, value);
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}
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return len;
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}
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static struct file_operations pci_ops = {
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.owner = THIS_MODULE,
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.read = pci_read,
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.write = pci_write,
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.open = pci_open,
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};
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/**
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* 0 => this driver doesn't handle this device
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* 1 => this driver handles this device
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*/
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static int pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
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{
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int i, ret, minor;
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struct cdev *cdev;
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dev_t devno;
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pr_info("pci_probe\n");
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ret = -1;
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for (i=0; i<MAX_DEVICE; i++) {
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if (pci_cdev[i].pci_dev == NULL) {
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pci_cdev[i].pci_dev = dev;
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minor = pci_cdev[i].minor;
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break;
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}
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}
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if (ret < 0) {
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dev_info(&(dev->dev), "error pci_cdev_add");
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goto error;
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}
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devno = MKDEV(major, minor);
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cdev = cdev_alloc();
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cdev_init(cdev, &pci_ops);
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cdev->owner = THIS_MODULE;
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/* register cdev */
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ret = cdev_add(cdev, devno, 1);
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if (ret < 0) {
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dev_err(&(dev->dev), "Can't register character device\n");
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goto error;
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}
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pci_cdev[minor].cdev = cdev;
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dev_info(&(dev->dev), "%s The major device number is %d (%d).\n",
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"Registeration is a success", MAJOR(devno), MINOR(devno));
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dev_info(&(dev->dev), "If you want to talk to the device driver,\n");
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dev_info(&(dev->dev), "you'll have to create a device file. \n");
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dev_info(&(dev->dev), "We suggest you use:\n");
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dev_info(&(dev->dev), "mknod %s c %d %d\n", DEVICE_NAME, MAJOR(devno), MINOR(devno));
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dev_info(&(dev->dev), "The device file name is important, because\n");
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dev_info(&(dev->dev), "the ioctl program assumes that's the\n");
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dev_info(&(dev->dev), "file you'll use.\n");
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/* enable the device */
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pci_enable_device(dev);
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/* 'alloc' IO to talk with the card */
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if (pci_request_region(dev, BAR_IO, "IO-pci") == 0) {
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dev_err(&(dev->dev), "Can't request BAR2\n");
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cdev_del(cdev);
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goto error;
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}
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/* check that BAR_IO is *really* IO region */
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if ((pci_resource_flags(dev, BAR_IO) & IORESOURCE_IO) != IORESOURCE_IO) {
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dev_err(&(dev->dev), "BAR2 isn't an IO region\n");
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cdev_del(cdev);
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goto error;
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}
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return 1;
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error:
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return 0;
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}
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static void pci_remove(struct pci_dev *dev)
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{
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int minor;
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struct cdev *cdev;
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minor = pci_cdev_search_minor(pci_cdev, MAX_DEVICE, dev);
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cdev = pci_cdev_search_cdev(pci_cdev, MAX_DEVICE, minor);
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if (cdev != NULL)
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cdev_del(cdev);
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pci_cdev_del(pci_cdev, MAX_DEVICE, dev);
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pci_release_region(dev, BAR_IO);
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}
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static struct pci_driver pci_driver = {
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.name = "pci",
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.id_table = pci_ids,
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.probe = pci_probe,
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.remove = pci_remove,
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};
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static int __init pci_init_module(void)
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{
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int i, first_minor, ret;
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ret = alloc_chrdev_region(&devno, 0, MAX_DEVICE, "buffer");
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major = MAJOR(devno);
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first_minor = MINOR(devno);
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for (i=0; i < MAX_DEVICE; i++) {
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pci_cdev[i].minor = first_minor++;
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pci_cdev[i].pci_dev = NULL;
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pci_cdev[i].cdev = NULL;
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}
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ret = pci_register_driver(&pci_driver);
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return 0;
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}
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static void pci_exit_module(void)
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{
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int i;
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pci_unregister_driver(&pci_driver);
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for(i=0; i< MAX_DEVICE; i++) {
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if (pci_cdev[i].pci_dev != NULL) {
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cdev_del(pci_cdev[i].cdev);
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}
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}
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unregister_chrdev_region(devno, MAX_DEVICE);
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}
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module_init(pci_init_module);
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module_exit(pci_exit_module);
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