drivers/pci/pci-stub.c

   1 /* pci-stub - simple stub driver to reserve a pci device
   2  *
   3  * Copyright (C) 2008 Red Hat, Inc.
   4  * Author:
   5  *      Chris Wright
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.
   8  *
   9  * Usage is simple, allocate a new id to the stub driver and bind the
  10  * device to it.  For example:
  11  *
  12  * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
  13  * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
  14  * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
  15  * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
  16  * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/pci.h>
  21
  22 static char ids[1024] __initdata;
  23
  24 module_param_string(ids, ids, sizeof(ids), 0);
  25 MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
  26                  "\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
  27                  " and multiple comma separated entries can be specified");
  28
  29 static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
  30 {
  31         dev_printk(KERN_INFO, &dev->dev, "claimed by stub\n");
  32         return 0;
  33 }
  34
  35 static struct pci_driver stub_driver = {
  36         .name           = "pci-stub",
  37         .id_table       = NULL, /* only dynamic id's */
  38         .probe          = pci_stub_probe,
  39 };
  40
  41 static int __init pci_stub_init(void)
  42 {
  43         char *p, *id;
  44         int rc;
  45
  46         rc = pci_register_driver(&stub_driver);
  47         if (rc)
  48                 return rc;
  49
  50         /* add ids specified in the module parameter */
  51         p = ids;
  52         while ((id = strsep(&p, ","))) {
  53                 unsigned int vendor, device, subvendor = PCI_ANY_ID,
  54                         subdevice = PCI_ANY_ID, class=0, class_mask=0;
  55                 int fields;
  56
  57                 if (!strlen(id))
  58                         continue;
  59
  60                 fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
  61                                 &vendor, &device, &subvendor, &subdevice,
  62                                 &class, &class_mask);
  63
  64                 if (fields < 2) {
  65                         printk(KERN_WARNING
  66                                "pci-stub: invalid id string \"%s\"\n", id);
  67                         continue;
  68                 }
  69
  70                 printk(KERN_INFO
  71                        "pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
  72                        vendor, device, subvendor, subdevice, class, class_mask);
  73
  74                 rc = pci_add_dynid(&stub_driver, vendor, device,
  75                                    subvendor, subdevice, class, class_mask, 0);
  76                 if (rc)
  77                         printk(KERN_WARNING
  78                                "pci-stub: failed to add dynamic id (%d)\n", rc);
  79         }
  80
  81         return 0;
  82 }
  83
  84 static void __exit pci_stub_exit(void)
  85 {
  86         pci_unregister_driver(&stub_driver);
  87 }
  88
  89 module_init(pci_stub_init);
  90 module_exit(pci_stub_exit);
  91
  92 MODULE_LICENSE("GPL");
  93 MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");