drivers/hid/hid-generic.c

   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");