linux/drivers/hid/hid-cougar.c
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   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
  14MODULE_AUTHOR("Daniel M. Lambea <dmlambea@gmail.com>");
  15MODULE_DESCRIPTION("Cougar 500k Gaming Keyboard");
  16MODULE_LICENSE("GPL");
  17MODULE_INFO(key_mappings, "G1-G6 are mapped to F13-F18");
  18
  19static bool g6_is_space = true;
  20MODULE_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 */
  48static 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
  68struct 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
  76struct cougar {
  77        bool special_intf;
  78        struct cougar_shared *shared;
  79};
  80
  81static LIST_HEAD(cougar_udev_list);
  82static DEFINE_MUTEX(cougar_udev_list_lock);
  83
  84/**
  85 * cougar_fix_g6_mapping - configure the mapping for key G6/Spacebar
  86 */
  87static 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 */
 106static __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
 119static 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
 133static 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
 145static 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 */
 159static 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
 189out:
 190        mutex_unlock(&cougar_udev_list_lock);
 191        return error;
 192}
 193
 194static 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
 250fail_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 */
 258static 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
 290static 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
 304static 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
 318static const struct kernel_param_ops cougar_g6_is_space_ops = {
 319        .set    = cougar_param_set_g6_is_space,
 320        .get    = param_get_bool,
 321};
 322module_param_cb(g6_is_space, &cougar_g6_is_space_ops, &g6_is_space, 0644);
 323
 324static 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};
 331MODULE_DEVICE_TABLE(hid, cougar_id_table);
 332
 333static 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
 342module_hid_driver(cougar_driver);
 343