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
22static char ids[1024] __initdata;
23
24module_param_string(ids, ids, sizeof(ids), 0);
25MODULE_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
29static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
30{
31	dev_info(&dev->dev, "claimed by stub\n");
32	return 0;
33}
34
35static struct pci_driver stub_driver = {
36	.name		= "pci-stub",
37	.id_table	= NULL,	/* only dynamic id's */
38	.probe		= pci_stub_probe,
39};
40
41static 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	/* no ids passed actually */
51	if (ids[0] == '\0')
52		return 0;
53
54	/* add ids specified in the module parameter */
55	p = ids;
56	while ((id = strsep(&p, ","))) {
57		unsigned int vendor, device, subvendor = PCI_ANY_ID,
58			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
59		int fields;
60
61		if (!strlen(id))
62			continue;
63
64		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
65				&vendor, &device, &subvendor, &subdevice,
66				&class, &class_mask);
67
68		if (fields < 2) {
69			printk(KERN_WARNING
70			       "pci-stub: invalid id string \"%s\"\n", id);
71			continue;
72		}
73
74		printk(KERN_INFO
75		       "pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
76		       vendor, device, subvendor, subdevice, class, class_mask);
77
78		rc = pci_add_dynid(&stub_driver, vendor, device,
79				   subvendor, subdevice, class, class_mask, 0);
80		if (rc)
81			printk(KERN_WARNING
82			       "pci-stub: failed to add dynamic id (%d)\n", rc);
83	}
84
85	return 0;
86}
87
88static void __exit pci_stub_exit(void)
89{
90	pci_unregister_driver(&stub_driver);
91}
92
93module_init(pci_stub_init);
94module_exit(pci_stub_exit);
95
96MODULE_LICENSE("GPL");
97MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");
98