drivers/hid/hid-cougar.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  HID driver for Cougar 500k Gaming Keyboard
   4  *
   5  *  Copyright (c) 2018 Daniel M. Lambea <dmlambea@gmail.com>
   6  */
   7
   8 #include <linux/hid.h>
   9 #include <linux/module.h>
  10
  11 #include "hid-ids.h"
  12
  13 MODULE_AUTHOR("Daniel M. Lambea <dmlambea@gmail.com>");
  14 MODULE_DESCRIPTION("Cougar 500k Gaming Keyboard");
  15 MODULE_LICENSE("GPL");
  16 MODULE_INFO(key_mappings, "G1-G6 are mapped to F13-F18");
  17
  18 static int cougar_g6_is_space = 1;
  19 module_param_named(g6_is_space, cougar_g6_is_space, int, 0600);
  20 MODULE_PARM_DESC(g6_is_space,
  21         "If set, G6 programmable key sends SPACE instead of F18 (0=off, 1=on) (default=1)");
  22
  23
  24 #define COUGAR_VENDOR_USAGE     0xff00ff00
  25
  26 #define COUGAR_FIELD_CODE       1
  27 #define COUGAR_FIELD_ACTION     2
  28
  29 #define COUGAR_KEY_G1           0x83
  30 #define COUGAR_KEY_G2           0x84
  31 #define COUGAR_KEY_G3           0x85
  32 #define COUGAR_KEY_G4           0x86
  33 #define COUGAR_KEY_G5           0x87
  34 #define COUGAR_KEY_G6           0x78
  35 #define COUGAR_KEY_FN           0x0d
  36 #define COUGAR_KEY_MR           0x6f
  37 #define COUGAR_KEY_M1           0x80
  38 #define COUGAR_KEY_M2           0x81
  39 #define COUGAR_KEY_M3           0x82
  40 #define COUGAR_KEY_LEDS         0x67
  41 #define COUGAR_KEY_LOCK         0x6e
  42
  43
  44 /* Default key mappings. The special key COUGAR_KEY_G6 is defined first
  45  * because it is more frequent to use the spacebar rather than any other
  46  * special keys. Depending on the value of the parameter 'g6_is_space',
  47  * the mapping will be updated in the probe function.
  48  */
  49 static unsigned char cougar_mapping[][2] = {
  50         { COUGAR_KEY_G6,   KEY_SPACE },
  51         { COUGAR_KEY_G1,   KEY_F13 },
  52         { COUGAR_KEY_G2,   KEY_F14 },
  53         { COUGAR_KEY_G3,   KEY_F15 },
  54         { COUGAR_KEY_G4,   KEY_F16 },
  55         { COUGAR_KEY_G5,   KEY_F17 },
  56         { COUGAR_KEY_LOCK, KEY_SCREENLOCK },
  57 /* The following keys are handled by the hardware itself, so no special
  58  * treatment is required:
  59         { COUGAR_KEY_FN, KEY_RESERVED },
  60         { COUGAR_KEY_MR, KEY_RESERVED },
  61         { COUGAR_KEY_M1, KEY_RESERVED },
  62         { COUGAR_KEY_M2, KEY_RESERVED },
  63         { COUGAR_KEY_M3, KEY_RESERVED },
  64         { COUGAR_KEY_LEDS, KEY_RESERVED },
  65 */
  66         { 0, 0 },
  67 };
  68
  69 struct cougar_shared {
  70         struct list_head list;
  71         struct kref kref;
  72         bool enabled;
  73         struct hid_device *dev;
  74         struct input_dev *input;
  75 };
  76
  77 struct cougar {
  78         bool special_intf;
  79         struct cougar_shared *shared;
  80 };
  81
  82 static LIST_HEAD(cougar_udev_list);
  83 static DEFINE_MUTEX(cougar_udev_list_lock);
  84
  85 static void cougar_fix_g6_mapping(struct hid_device *hdev)
  86 {
  87         int i;
  88
  89         for (i = 0; cougar_mapping[i][0]; i++) {
  90                 if (cougar_mapping[i][0] == COUGAR_KEY_G6) {
  91                         cougar_mapping[i][1] =
  92                                 cougar_g6_is_space ? KEY_SPACE : KEY_F18;
  93                         hid_info(hdev, "G6 mapped to %s\n",
  94                                  cougar_g6_is_space ? "space" : "F18");
  95                         return;
  96                 }
  97         }
  98         hid_warn(hdev, "no mapping defined for G6/spacebar");
  99 }
 100
 101 /*
 102  * Constant-friendly rdesc fixup for mouse interface
 103  */
 104 static __u8 *cougar_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 105                                  unsigned int *rsize)
 106 {
 107         if (rdesc[2] == 0x09 && rdesc[3] == 0x02 &&
 108             (rdesc[115] | rdesc[116] << 8) >= HID_MAX_USAGES) {
 109                 hid_info(hdev,
 110                         "usage count exceeds max: fixing up report descriptor\n");
 111                 rdesc[115] = ((HID_MAX_USAGES-1) & 0xff);
 112                 rdesc[116] = ((HID_MAX_USAGES-1) >> 8);
 113         }
 114         return rdesc;
 115 }
 116
 117 static struct cougar_shared *cougar_get_shared_data(struct hid_device *hdev)
 118 {
 119         struct cougar_shared *shared;
 120
 121         /* Try to find an already-probed interface from the same device */
 122         list_for_each_entry(shared, &cougar_udev_list, list) {
 123                 if (hid_compare_device_paths(hdev, shared->dev, '/')) {
 124                         kref_get(&shared->kref);
 125                         return shared;
 126                 }
 127         }
 128         return NULL;
 129 }
 130
 131 static void cougar_release_shared_data(struct kref *kref)
 132 {
 133         struct cougar_shared *shared = container_of(kref,
 134                                                     struct cougar_shared, kref);
 135
 136         mutex_lock(&cougar_udev_list_lock);
 137         list_del(&shared->list);
 138         mutex_unlock(&cougar_udev_list_lock);
 139
 140         kfree(shared);
 141 }
 142
 143 static void cougar_remove_shared_data(void *resource)
 144 {
 145         struct cougar *cougar = resource;
 146
 147         if (cougar->shared) {
 148                 kref_put(&cougar->shared->kref, cougar_release_shared_data);
 149                 cougar->shared = NULL;
 150         }
 151 }
 152
 153 /*
 154  * Bind the device group's shared data to this cougar struct.
 155  * If no shared data exists for this group, create and initialize it.
 156  */
 157 static int cougar_bind_shared_data(struct hid_device *hdev, struct cougar *cougar)
 158 {
 159         struct cougar_shared *shared;
 160         int error = 0;
 161
 162         mutex_lock(&cougar_udev_list_lock);
 163
 164         shared = cougar_get_shared_data(hdev);
 165         if (!shared) {
 166                 shared = kzalloc(sizeof(*shared), GFP_KERNEL);
 167                 if (!shared) {
 168                         error = -ENOMEM;
 169                         goto out;
 170                 }
 171
 172                 kref_init(&shared->kref);
 173                 shared->dev = hdev;
 174                 list_add_tail(&shared->list, &cougar_udev_list);
 175         }
 176
 177         cougar->shared = shared;
 178
 179         error = devm_add_action(&hdev->dev, cougar_remove_shared_data, cougar);
 180         if (error) {
 181                 mutex_unlock(&cougar_udev_list_lock);
 182                 cougar_remove_shared_data(cougar);
 183                 return error;
 184         }
 185
 186 out:
 187         mutex_unlock(&cougar_udev_list_lock);
 188         return error;
 189 }
 190
 191 static int cougar_probe(struct hid_device *hdev,
 192                         const struct hid_device_id *id)
 193 {
 194         struct cougar *cougar;
 195         struct hid_input *next, *hidinput = NULL;
 196         unsigned int connect_mask;
 197         int error;
 198
 199         cougar = devm_kzalloc(&hdev->dev, sizeof(*cougar), GFP_KERNEL);
 200         if (!cougar)
 201                 return -ENOMEM;
 202         hid_set_drvdata(hdev, cougar);
 203
 204         error = hid_parse(hdev);
 205         if (error) {
 206                 hid_err(hdev, "parse failed\n");
 207                 goto fail;
 208         }
 209
 210         if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
 211                 cougar->special_intf = true;
 212                 connect_mask = HID_CONNECT_HIDRAW;
 213         } else
 214                 connect_mask = HID_CONNECT_DEFAULT;
 215
 216         error = hid_hw_start(hdev, connect_mask);
 217         if (error) {
 218                 hid_err(hdev, "hw start failed\n");
 219                 goto fail;
 220         }
 221
 222         error = cougar_bind_shared_data(hdev, cougar);
 223         if (error)
 224                 goto fail_stop_and_cleanup;
 225
 226         /* The custom vendor interface will use the hid_input registered
 227          * for the keyboard interface, in order to send translated key codes
 228          * to it.
 229          */
 230         if (hdev->collection->usage == HID_GD_KEYBOARD) {
 231                 cougar_fix_g6_mapping(hdev);
 232                 list_for_each_entry_safe(hidinput, next, &hdev->inputs, list) {
 233                         if (hidinput->registered && hidinput->input != NULL) {
 234                                 cougar->shared->input = hidinput->input;
 235                                 cougar->shared->enabled = true;
 236                                 break;
 237                         }
 238                 }
 239         } else if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
 240                 error = hid_hw_open(hdev);
 241                 if (error)
 242                         goto fail_stop_and_cleanup;
 243         }
 244         return 0;
 245
 246 fail_stop_and_cleanup:
 247         hid_hw_stop(hdev);
 248 fail:
 249         hid_set_drvdata(hdev, NULL);
 250         return error;
 251 }
 252
 253 /*
 254  * Convert events from vendor intf to input key events
 255  */
 256 static int cougar_raw_event(struct hid_device *hdev, struct hid_report *report,
 257                             u8 *data, int size)
 258 {
 259         struct cougar *cougar;
 260         unsigned char code, action;
 261         int i;
 262
 263         cougar = hid_get_drvdata(hdev);
 264         if (!cougar->special_intf || !cougar->shared ||
 265             !cougar->shared->input || !cougar->shared->enabled)
 266                 return 0;
 267
 268         code = data[COUGAR_FIELD_CODE];
 269         action = data[COUGAR_FIELD_ACTION];
 270         for (i = 0; cougar_mapping[i][0]; i++) {
 271                 if (code == cougar_mapping[i][0]) {
 272                         input_event(cougar->shared->input, EV_KEY,
 273                                     cougar_mapping[i][1], action);
 274                         input_sync(cougar->shared->input);
 275                         return 0;
 276                 }
 277         }
 278         hid_warn(hdev, "unmapped special key code %x: ignoring\n", code);
 279         return 0;
 280 }
 281
 282 static void cougar_remove(struct hid_device *hdev)
 283 {
 284         struct cougar *cougar = hid_get_drvdata(hdev);
 285
 286         if (cougar) {
 287                 /* Stop the vendor intf to process more events */
 288                 if (cougar->shared)
 289                         cougar->shared->enabled = false;
 290                 if (cougar->special_intf)
 291                         hid_hw_close(hdev);
 292         }
 293         hid_hw_stop(hdev);
 294 }
 295
 296 static struct hid_device_id cougar_id_table[] = {
 297         { HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
 298                          USB_DEVICE_ID_COUGAR_500K_GAMING_KEYBOARD) },
 299         {}
 300 };
 301 MODULE_DEVICE_TABLE(hid, cougar_id_table);
 302
 303 static struct hid_driver cougar_driver = {
 304         .name                   = "cougar",
 305         .id_table               = cougar_id_table,
 306         .report_fixup           = cougar_report_fixup,
 307         .probe                  = cougar_probe,
 308         .remove                 = cougar_remove,
 309         .raw_event              = cougar_raw_event,
 310 };
 311
 312 module_hid_driver(cougar_driver);