xref: /openbmc/linux/drivers/hid/hid-generic.c (revision feac8c8b)
1 /*
2  *  HID support for Linux
3  *
4  *  Copyright (c) 1999 Andreas Gal
5  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
6  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
7  *  Copyright (c) 2007-2008 Oliver Neukum
8  *  Copyright (c) 2006-2012 Jiri Kosina
9  *  Copyright (c) 2012 Henrik Rydberg
10  */
11 
12 /*
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms of the GNU General Public License as published by the Free
15  * Software Foundation; either version 2 of the License, or (at your option)
16  * any later version.
17  */
18 
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/kernel.h>
22 #include <asm/unaligned.h>
23 #include <asm/byteorder.h>
24 
25 #include <linux/hid.h>
26 
27 static struct hid_driver hid_generic;
28 
29 static int __unmap_hid_generic(struct device *dev, void *data)
30 {
31 	struct hid_driver *hdrv = data;
32 	struct hid_device *hdev = to_hid_device(dev);
33 
34 	/* only unbind matching devices already bound to hid-generic */
35 	if (hdev->driver != &hid_generic ||
36 	    hid_match_device(hdev, hdrv) == NULL)
37 		return 0;
38 
39 	if (dev->parent)	/* Needed for USB */
40 		device_lock(dev->parent);
41 	device_release_driver(dev);
42 	if (dev->parent)
43 		device_unlock(dev->parent);
44 
45 	return 0;
46 }
47 
48 static void hid_generic_add_driver(struct hid_driver *hdrv)
49 {
50 	bus_for_each_dev(&hid_bus_type, NULL, hdrv, __unmap_hid_generic);
51 }
52 
53 static void hid_generic_removed_driver(struct hid_driver *hdrv)
54 {
55 	int ret;
56 
57 	ret = driver_attach(&hid_generic.driver);
58 }
59 
60 static int __check_hid_generic(struct device_driver *drv, void *data)
61 {
62 	struct hid_driver *hdrv = to_hid_driver(drv);
63 	struct hid_device *hdev = data;
64 
65 	if (hdrv == &hid_generic)
66 		return 0;
67 
68 	return hid_match_device(hdev, hdrv) != NULL;
69 }
70 
71 static bool hid_generic_match(struct hid_device *hdev,
72 			      bool ignore_special_driver)
73 {
74 	if (ignore_special_driver)
75 		return true;
76 
77 	if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)
78 		return false;
79 
80 	/*
81 	 * If any other driver wants the device, leave the device to this other
82 	 * driver.
83 	 */
84 	if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic))
85 		return false;
86 
87 	return true;
88 }
89 
90 static const struct hid_device_id hid_table[] = {
91 	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) },
92 	{ }
93 };
94 MODULE_DEVICE_TABLE(hid, hid_table);
95 
96 static struct hid_driver hid_generic = {
97 	.name = "hid-generic",
98 	.id_table = hid_table,
99 	.match = hid_generic_match,
100 	.bus_add_driver = hid_generic_add_driver,
101 	.bus_removed_driver = hid_generic_removed_driver,
102 };
103 module_hid_driver(hid_generic);
104 
105 MODULE_AUTHOR("Henrik Rydberg");
106 MODULE_DESCRIPTION("HID generic driver");
107 MODULE_LICENSE("GPL");
108