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 #include <linux/printk.h>
  11
  12 #include "hid-ids.h"
  13
  14 MODULE_AUTHOR("Daniel M. Lambea <dmlambea@gmail.com>");
  15 MODULE_DESCRIPTION("Cougar 500k Gaming Keyboard");
  16 MODULE_LICENSE("GPL");
  17 MODULE_INFO(key_mappings, "G1-G6 are mapped to F13-F18");
  18
  19 static bool g6_is_space = true;
  20 MODULE_PARM_DESC(g6_is_space,
  21         "If true, G6 programmable key sends SPACE instead of F18 (default=true)");
  22
  23 #define COUGAR_VENDOR_USAGE     0xff00ff00
  24
  25 #define COUGAR_FIELD_CODE       1
  26 #define COUGAR_FIELD_ACTION     2
  27
  28 #define COUGAR_KEY_G1           0x83
  29 #define COUGAR_KEY_G2           0x84
  30 #define COUGAR_KEY_G3           0x85
  31 #define COUGAR_KEY_G4           0x86
  32 #define COUGAR_KEY_G5           0x87
  33 #define COUGAR_KEY_G6           0x78
  34 #define COUGAR_KEY_FN           0x0d
  35 #define COUGAR_KEY_MR           0x6f
  36 #define COUGAR_KEY_M1           0x80
  37 #define COUGAR_KEY_M2           0x81
  38 #define COUGAR_KEY_M3           0x82
  39 #define COUGAR_KEY_LEDS         0x67
  40 #define COUGAR_KEY_LOCK         0x6e
  41
  42
  43 /* Default key mappings. The special key COUGAR_KEY_G6 is defined first
  44  * because it is more frequent to use the spacebar rather than any other
  45  * special keys. Depending on the value of the parameter 'g6_is_space',
  46  * the mapping will be updated in the probe function.
  47  */
  48 static unsigned char cougar_mapping[][2] = {
  49         { COUGAR_KEY_G6,   KEY_SPACE },
  50         { COUGAR_KEY_G1,   KEY_F13 },
  51         { COUGAR_KEY_G2,   KEY_F14 },
  52         { COUGAR_KEY_G3,   KEY_F15 },
  53         { COUGAR_KEY_G4,   KEY_F16 },
  54         { COUGAR_KEY_G5,   KEY_F17 },
  55         { COUGAR_KEY_LOCK, KEY_SCREENLOCK },
  56 /* The following keys are handled by the hardware itself, so no special
  57  * treatment is required:
  58         { COUGAR_KEY_FN, KEY_RESERVED },
  59         { COUGAR_KEY_MR, KEY_RESERVED },
  60         { COUGAR_KEY_M1, KEY_RESERVED },
  61         { COUGAR_KEY_M2, KEY_RESERVED },
  62         { COUGAR_KEY_M3, KEY_RESERVED },
  63         { COUGAR_KEY_LEDS, KEY_RESERVED },
  64 */
  65         { 0, 0 },
  66 };
  67
  68 struct cougar_shared {
  69         struct list_head list;
  70         struct kref kref;
  71         bool enabled;
  72         struct hid_device *dev;
  73         struct input_dev *input;
  74 };
  75
  76 struct cougar {
  77         bool special_intf;
  78         struct cougar_shared *shared;
  79 };
  80
  81 static LIST_HEAD(cougar_udev_list);
  82 static DEFINE_MUTEX(cougar_udev_list_lock);
  83
  84 /**
  85  * cougar_fix_g6_mapping - configure the mapping for key G6/Spacebar
  86  */
  87 static void cougar_fix_g6_mapping(void)
  88 {
  89         int i;
  90
  91         for (i = 0; cougar_mapping[i][0]; i++) {
  92                 if (cougar_mapping[i][0] == COUGAR_KEY_G6) {
  93                         cougar_mapping[i][1] =
  94                                 g6_is_space ? KEY_SPACE : KEY_F18;
  95                         pr_info("cougar: G6 mapped to %s\n",
  96                                 g6_is_space ? "space" : "F18");
  97                         return;
  98                 }
  99         }
 100         pr_warn("cougar: no mappings defined for G6/spacebar");
 101 }
 102
 103 /*
 104  * Constant-friendly rdesc fixup for mouse interface
 105  */
 106 static __u8 *cougar_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 107                                  unsigned int *rsize)
 108 {
 109         if (rdesc[2] == 0x09 && rdesc[3] == 0x02 &&
 110             (rdesc[115] | rdesc[116] << 8) >= HID_MAX_USAGES) {
 111                 hid_info(hdev,
 112                         "usage count exceeds max: fixing up report descriptor\n");
 113                 rdesc[115] = ((HID_MAX_USAGES-1) & 0xff);
 114                 rdesc[116] = ((HID_MAX_USAGES-1) >> 8);
 115         }
 116         return rdesc;
 117 }
 118
 119 static struct cougar_shared *cougar_get_shared_data(struct hid_device *hdev)
 120 {
 121         struct cougar_shared *shared;
 122
 123         /* Try to find an already-probed interface from the same device */
 124         list_for_each_entry(shared, &cougar_udev_list, list) {
 125                 if (hid_compare_device_paths(hdev, shared->dev, '/')) {
 126                         kref_get(&shared->kref);
 127                         return shared;
 128                 }
 129         }
 130         return NULL;
 131 }
 132
 133 static void cougar_release_shared_data(struct kref *kref)
 134 {
 135         struct cougar_shared *shared = container_of(kref,
 136                                                     struct cougar_shared, kref);
 137
 138         mutex_lock(&cougar_udev_list_lock);
 139         list_del(&shared->list);
 140         mutex_unlock(&cougar_udev_list_lock);
 141
 142         kfree(shared);
 143 }
 144
 145 static void cougar_remove_shared_data(void *resource)
 146 {
 147         struct cougar *cougar = resource;
 148
 149         if (cougar->shared) {
 150                 kref_put(&cougar->shared->kref, cougar_release_shared_data);
 151                 cougar->shared = NULL;
 152         }
 153 }
 154
 155 /*
 156  * Bind the device group's shared data to this cougar struct.
 157  * If no shared data exists for this group, create and initialize it.
 158  */
 159 static int cougar_bind_shared_data(struct hid_device *hdev,
 160                                    struct cougar *cougar)
 161 {
 162         struct cougar_shared *shared;
 163         int error = 0;
 164
 165         mutex_lock(&cougar_udev_list_lock);
 166
 167         shared = cougar_get_shared_data(hdev);
 168         if (!shared) {
 169                 shared = kzalloc(sizeof(*shared), GFP_KERNEL);
 170                 if (!shared) {
 171                         error = -ENOMEM;
 172                         goto out;
 173                 }
 174
 175                 kref_init(&shared->kref);
 176                 shared->dev = hdev;
 177                 list_add_tail(&shared->list, &cougar_udev_list);
 178         }
 179
 180         cougar->shared = shared;
 181
 182         error = devm_add_action(&hdev->dev, cougar_remove_shared_data, cougar);
 183         if (error) {
 184                 mutex_unlock(&cougar_udev_list_lock);
 185                 cougar_remove_shared_data(cougar);
 186                 return error;
 187         }
 188
 189 out:
 190         mutex_unlock(&cougar_udev_list_lock);
 191         return error;
 192 }
 193
 194 static int cougar_probe(struct hid_device *hdev,
 195                         const struct hid_device_id *id)
 196 {
 197         struct cougar *cougar;
 198         struct hid_input *next, *hidinput = NULL;
 199         unsigned int connect_mask;
 200         int error;
 201
 202         cougar = devm_kzalloc(&hdev->dev, sizeof(*cougar), GFP_KERNEL);
 203         if (!cougar)
 204                 return -ENOMEM;
 205         hid_set_drvdata(hdev, cougar);
 206
 207         error = hid_parse(hdev);
 208         if (error) {
 209                 hid_err(hdev, "parse failed\n");
 210                 return error;
 211         }
 212
 213         if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
 214                 cougar->special_intf = true;
 215                 connect_mask = HID_CONNECT_HIDRAW;
 216         } else
 217                 connect_mask = HID_CONNECT_DEFAULT;
 218
 219         error = hid_hw_start(hdev, connect_mask);
 220         if (error) {
 221                 hid_err(hdev, "hw start failed\n");
 222                 return error;
 223         }
 224
 225         error = cougar_bind_shared_data(hdev, cougar);
 226         if (error)
 227                 goto fail_stop_and_cleanup;
 228
 229         /* The custom vendor interface will use the hid_input registered
 230          * for the keyboard interface, in order to send translated key codes
 231          * to it.
 232          */
 233         if (hdev->collection->usage == HID_GD_KEYBOARD) {
 234                 list_for_each_entry_safe(hidinput, next, &hdev->inputs, list) {
 235                         if (hidinput->registered && hidinput->input != NULL) {
 236                                 cougar->shared->input = hidinput->input;
 237                                 cougar->shared->enabled = true;
 238                                 break;
 239                         }
 240                 }
 241         } else if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
 242                 /* Preinit the mapping table */
 243                 cougar_fix_g6_mapping();
 244                 error = hid_hw_open(hdev);
 245                 if (error)
 246                         goto fail_stop_and_cleanup;
 247         }
 248         return 0;
 249
 250 fail_stop_and_cleanup:
 251         hid_hw_stop(hdev);
 252         return error;
 253 }
 254
 255 /*
 256  * Convert events from vendor intf to input key events
 257  */
 258 static int cougar_raw_event(struct hid_device *hdev, struct hid_report *report,
 259                             u8 *data, int size)
 260 {
 261         struct cougar *cougar;
 262         struct cougar_shared *shared;
 263         unsigned char code, action;
 264         int i;
 265
 266         cougar = hid_get_drvdata(hdev);
 267         shared = cougar->shared;
 268         if (!cougar->special_intf || !shared)
 269                 return 0;
 270
 271         if (!shared->enabled || !shared->input)
 272                 return -EPERM;
 273
 274         code = data[COUGAR_FIELD_CODE];
 275         action = data[COUGAR_FIELD_ACTION];
 276         for (i = 0; cougar_mapping[i][0]; i++) {
 277                 if (code == cougar_mapping[i][0]) {
 278                         input_event(shared->input, EV_KEY,
 279                                     cougar_mapping[i][1], action);
 280                         input_sync(shared->input);
 281                         return -EPERM;
 282                 }
 283         }
 284         /* Avoid warnings on the same unmapped key twice */
 285         if (action != 0)
 286                 hid_warn(hdev, "unmapped special key code %0x: ignoring\n", code);
 287         return -EPERM;
 288 }
 289
 290 static void cougar_remove(struct hid_device *hdev)
 291 {
 292         struct cougar *cougar = hid_get_drvdata(hdev);
 293
 294         if (cougar) {
 295                 /* Stop the vendor intf to process more events */
 296                 if (cougar->shared)
 297                         cougar->shared->enabled = false;
 298                 if (cougar->special_intf)
 299                         hid_hw_close(hdev);
 300         }
 301         hid_hw_stop(hdev);
 302 }
 303
 304 static int cougar_param_set_g6_is_space(const char *val,
 305                                         const struct kernel_param *kp)
 306 {
 307         int ret;
 308
 309         ret = param_set_bool(val, kp);
 310         if (ret)
 311                 return ret;
 312
 313         cougar_fix_g6_mapping();
 314
 315         return 0;
 316 }
 317
 318 static const struct kernel_param_ops cougar_g6_is_space_ops = {
 319         .set    = cougar_param_set_g6_is_space,
 320         .get    = param_get_bool,
 321 };
 322 module_param_cb(g6_is_space, &cougar_g6_is_space_ops, &g6_is_space, 0644);
 323
 324 static const struct hid_device_id cougar_id_table[] = {
 325         { HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
 326                          USB_DEVICE_ID_COUGAR_500K_GAMING_KEYBOARD) },
 327         { HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
 328                          USB_DEVICE_ID_COUGAR_700K_GAMING_KEYBOARD) },
 329         {}
 330 };
 331 MODULE_DEVICE_TABLE(hid, cougar_id_table);
 332
 333 static struct hid_driver cougar_driver = {
 334         .name                   = "cougar",
 335         .id_table               = cougar_id_table,
 336         .report_fixup           = cougar_report_fixup,
 337         .probe                  = cougar_probe,
 338         .remove                 = cougar_remove,
 339         .raw_event              = cougar_raw_event,
 340 };
 341
 342 module_hid_driver(cougar_driver);