drivers/staging/greybus/hid.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * HID class driver for the Greybus.
   4  *
   5  * Copyright 2014 Google Inc.
   6  * Copyright 2014 Linaro Ltd.
   7  */
   8
   9 #include <linux/bitops.h>
  10 #include <linux/hid.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/slab.h>
  15
  16 #include "greybus.h"
  17
  18 /* Greybus HID device's structure */
  19 struct gb_hid {
  20         struct gb_bundle *bundle;
  21         struct gb_connection            *connection;
  22
  23         struct hid_device               *hid;
  24         struct gb_hid_desc_response     hdesc;
  25
  26         unsigned long                   flags;
  27 #define GB_HID_STARTED                  0x01
  28 #define GB_HID_READ_PENDING             0x04
  29
  30         unsigned int                    bufsize;
  31         char                            *inbuf;
  32 };
  33
  34 /* Routines to get controller's information over greybus */
  35
  36 /* Operations performed on greybus */
  37 static int gb_hid_get_desc(struct gb_hid *ghid)
  38 {
  39         return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_DESC, NULL,
  40                                  0, &ghid->hdesc, sizeof(ghid->hdesc));
  41 }
  42
  43 static int gb_hid_get_report_desc(struct gb_hid *ghid, char *rdesc)
  44 {
  45         int ret;
  46
  47         ret = gb_pm_runtime_get_sync(ghid->bundle);
  48         if (ret)
  49                 return ret;
  50
  51         ret = gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT_DESC,
  52                                  NULL, 0, rdesc,
  53                                  le16_to_cpu(ghid->hdesc.wReportDescLength));
  54
  55         gb_pm_runtime_put_autosuspend(ghid->bundle);
  56
  57         return ret;
  58 }
  59
  60 static int gb_hid_set_power(struct gb_hid *ghid, int type)
  61 {
  62         int ret;
  63
  64         ret = gb_pm_runtime_get_sync(ghid->bundle);
  65         if (ret)
  66                 return ret;
  67
  68         ret = gb_operation_sync(ghid->connection, type, NULL, 0, NULL, 0);
  69
  70         gb_pm_runtime_put_autosuspend(ghid->bundle);
  71
  72         return ret;
  73 }
  74
  75 static int gb_hid_get_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
  76                              unsigned char *buf, int len)
  77 {
  78         struct gb_hid_get_report_request request;
  79         int ret;
  80
  81         ret = gb_pm_runtime_get_sync(ghid->bundle);
  82         if (ret)
  83                 return ret;
  84
  85         request.report_type = report_type;
  86         request.report_id = report_id;
  87
  88         ret = gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT,
  89                                  &request, sizeof(request), buf, len);
  90
  91         gb_pm_runtime_put_autosuspend(ghid->bundle);
  92
  93         return ret;
  94 }
  95
  96 static int gb_hid_set_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
  97                              unsigned char *buf, int len)
  98 {
  99         struct gb_hid_set_report_request *request;
 100         struct gb_operation *operation;
 101         int ret, size = sizeof(*request) + len - 1;
 102
 103         ret = gb_pm_runtime_get_sync(ghid->bundle);
 104         if (ret)
 105                 return ret;
 106
 107         operation = gb_operation_create(ghid->connection,
 108                                         GB_HID_TYPE_SET_REPORT, size, 0,
 109                                         GFP_KERNEL);
 110         if (!operation) {
 111                 gb_pm_runtime_put_autosuspend(ghid->bundle);
 112                 return -ENOMEM;
 113         }
 114
 115         request = operation->request->payload;
 116         request->report_type = report_type;
 117         request->report_id = report_id;
 118         memcpy(request->report, buf, len);
 119
 120         ret = gb_operation_request_send_sync(operation);
 121         if (ret) {
 122                 dev_err(&operation->connection->bundle->dev,
 123                         "failed to set report: %d\n", ret);
 124         } else {
 125                 ret = len;
 126         }
 127
 128         gb_operation_put(operation);
 129         gb_pm_runtime_put_autosuspend(ghid->bundle);
 130
 131         return ret;
 132 }
 133
 134 static int gb_hid_request_handler(struct gb_operation *op)
 135 {
 136         struct gb_connection *connection = op->connection;
 137         struct gb_hid *ghid = gb_connection_get_data(connection);
 138         struct gb_hid_input_report_request *request = op->request->payload;
 139
 140         if (op->type != GB_HID_TYPE_IRQ_EVENT) {
 141                 dev_err(&connection->bundle->dev,
 142                         "unsupported unsolicited request\n");
 143                 return -EINVAL;
 144         }
 145
 146         if (test_bit(GB_HID_STARTED, &ghid->flags))
 147                 hid_input_report(ghid->hid, HID_INPUT_REPORT,
 148                                  request->report, op->request->payload_size, 1);
 149
 150         return 0;
 151 }
 152
 153 static int gb_hid_report_len(struct hid_report *report)
 154 {
 155         return ((report->size - 1) >> 3) + 1 +
 156                 report->device->report_enum[report->type].numbered;
 157 }
 158
 159 static void gb_hid_find_max_report(struct hid_device *hid, unsigned int type,
 160                                    unsigned int *max)
 161 {
 162         struct hid_report *report;
 163         unsigned int size;
 164
 165         list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
 166                 size = gb_hid_report_len(report);
 167                 if (*max < size)
 168                         *max = size;
 169         }
 170 }
 171
 172 static void gb_hid_free_buffers(struct gb_hid *ghid)
 173 {
 174         kfree(ghid->inbuf);
 175         ghid->inbuf = NULL;
 176         ghid->bufsize = 0;
 177 }
 178
 179 static int gb_hid_alloc_buffers(struct gb_hid *ghid, size_t bufsize)
 180 {
 181         ghid->inbuf = kzalloc(bufsize, GFP_KERNEL);
 182         if (!ghid->inbuf)
 183                 return -ENOMEM;
 184
 185         ghid->bufsize = bufsize;
 186
 187         return 0;
 188 }
 189
 190 /* Routines dealing with reports */
 191 static void gb_hid_init_report(struct gb_hid *ghid, struct hid_report *report)
 192 {
 193         unsigned int size;
 194
 195         size = gb_hid_report_len(report);
 196         if (gb_hid_get_report(ghid, report->type, report->id, ghid->inbuf,
 197                               size))
 198                 return;
 199
 200         /*
 201          * hid->driver_lock is held as we are in probe function,
 202          * we just need to setup the input fields, so using
 203          * hid_report_raw_event is safe.
 204          */
 205         hid_report_raw_event(ghid->hid, report->type, ghid->inbuf, size, 1);
 206 }
 207
 208 static void gb_hid_init_reports(struct gb_hid *ghid)
 209 {
 210         struct hid_device *hid = ghid->hid;
 211         struct hid_report *report;
 212
 213         list_for_each_entry(report,
 214                 &hid->report_enum[HID_INPUT_REPORT].report_list, list)
 215                 gb_hid_init_report(ghid, report);
 216
 217         list_for_each_entry(report,
 218                 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
 219                 gb_hid_init_report(ghid, report);
 220 }
 221
 222 static int __gb_hid_get_raw_report(struct hid_device *hid,
 223                 unsigned char report_number, __u8 *buf, size_t count,
 224                 unsigned char report_type)
 225 {
 226         struct gb_hid *ghid = hid->driver_data;
 227         int ret;
 228
 229         if (report_type == HID_OUTPUT_REPORT)
 230                 return -EINVAL;
 231
 232         ret = gb_hid_get_report(ghid, report_type, report_number, buf, count);
 233         if (!ret)
 234                 ret = count;
 235
 236         return ret;
 237 }
 238
 239 static int __gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 240                                       size_t len, unsigned char report_type)
 241 {
 242         struct gb_hid *ghid = hid->driver_data;
 243         int report_id = buf[0];
 244         int ret;
 245
 246         if (report_type == HID_INPUT_REPORT)
 247                 return -EINVAL;
 248
 249         if (report_id) {
 250                 buf++;
 251                 len--;
 252         }
 253
 254         ret = gb_hid_set_report(ghid, report_type, report_id, buf, len);
 255         if (report_id && ret >= 0)
 256                 ret++; /* add report_id to the number of transfered bytes */
 257
 258         return 0;
 259 }
 260
 261 static int gb_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
 262                                __u8 *buf, size_t len, unsigned char rtype,
 263                                int reqtype)
 264 {
 265         switch (reqtype) {
 266         case HID_REQ_GET_REPORT:
 267                 return __gb_hid_get_raw_report(hid, reportnum, buf, len, rtype);
 268         case HID_REQ_SET_REPORT:
 269                 if (buf[0] != reportnum)
 270                         return -EINVAL;
 271                 return __gb_hid_output_raw_report(hid, buf, len, rtype);
 272         default:
 273                 return -EIO;
 274         }
 275 }
 276
 277 /* HID Callbacks */
 278 static int gb_hid_parse(struct hid_device *hid)
 279 {
 280         struct gb_hid *ghid = hid->driver_data;
 281         unsigned int rsize;
 282         char *rdesc;
 283         int ret;
 284
 285         rsize = le16_to_cpu(ghid->hdesc.wReportDescLength);
 286         if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
 287                 dbg_hid("weird size of report descriptor (%u)\n", rsize);
 288                 return -EINVAL;
 289         }
 290
 291         rdesc = kzalloc(rsize, GFP_KERNEL);
 292         if (!rdesc) {
 293                 dbg_hid("couldn't allocate rdesc memory\n");
 294                 return -ENOMEM;
 295         }
 296
 297         ret = gb_hid_get_report_desc(ghid, rdesc);
 298         if (ret) {
 299                 hid_err(hid, "reading report descriptor failed\n");
 300                 goto free_rdesc;
 301         }
 302
 303         ret = hid_parse_report(hid, rdesc, rsize);
 304         if (ret)
 305                 dbg_hid("parsing report descriptor failed\n");
 306
 307 free_rdesc:
 308         kfree(rdesc);
 309
 310         return ret;
 311 }
 312
 313 static int gb_hid_start(struct hid_device *hid)
 314 {
 315         struct gb_hid *ghid = hid->driver_data;
 316         unsigned int bufsize = HID_MIN_BUFFER_SIZE;
 317         int ret;
 318
 319         gb_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
 320         gb_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
 321         gb_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
 322
 323         if (bufsize > HID_MAX_BUFFER_SIZE)
 324                 bufsize = HID_MAX_BUFFER_SIZE;
 325
 326         ret = gb_hid_alloc_buffers(ghid, bufsize);
 327         if (ret)
 328                 return ret;
 329
 330         if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
 331                 gb_hid_init_reports(ghid);
 332
 333         return 0;
 334 }
 335
 336 static void gb_hid_stop(struct hid_device *hid)
 337 {
 338         struct gb_hid *ghid = hid->driver_data;
 339
 340         gb_hid_free_buffers(ghid);
 341 }
 342
 343 static int gb_hid_open(struct hid_device *hid)
 344 {
 345         struct gb_hid *ghid = hid->driver_data;
 346         int ret;
 347
 348         ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
 349         if (ret < 0)
 350                 return ret;
 351
 352         set_bit(GB_HID_STARTED, &ghid->flags);
 353         return 0;
 354 }
 355
 356 static void gb_hid_close(struct hid_device *hid)
 357 {
 358         struct gb_hid *ghid = hid->driver_data;
 359         int ret;
 360
 361         clear_bit(GB_HID_STARTED, &ghid->flags);
 362
 363         /* Save some power */
 364         ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
 365         if (ret)
 366                 dev_err(&ghid->connection->bundle->dev,
 367                         "failed to power off (%d)\n", ret);
 368 }
 369
 370 static int gb_hid_power(struct hid_device *hid, int lvl)
 371 {
 372         struct gb_hid *ghid = hid->driver_data;
 373
 374         switch (lvl) {
 375         case PM_HINT_FULLON:
 376                 return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
 377         case PM_HINT_NORMAL:
 378                 return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
 379         }
 380
 381         return 0;
 382 }
 383
 384 /* HID structure to pass callbacks */
 385 static struct hid_ll_driver gb_hid_ll_driver = {
 386         .parse = gb_hid_parse,
 387         .start = gb_hid_start,
 388         .stop = gb_hid_stop,
 389         .open = gb_hid_open,
 390         .close = gb_hid_close,
 391         .power = gb_hid_power,
 392         .raw_request = gb_hid_raw_request,
 393 };
 394
 395 static int gb_hid_init(struct gb_hid *ghid)
 396 {
 397         struct hid_device *hid = ghid->hid;
 398         int ret;
 399
 400         ret = gb_hid_get_desc(ghid);
 401         if (ret)
 402                 return ret;
 403
 404         hid->version = le16_to_cpu(ghid->hdesc.bcdHID);
 405         hid->vendor = le16_to_cpu(ghid->hdesc.wVendorID);
 406         hid->product = le16_to_cpu(ghid->hdesc.wProductID);
 407         hid->country = ghid->hdesc.bCountryCode;
 408
 409         hid->driver_data = ghid;
 410         hid->ll_driver = &gb_hid_ll_driver;
 411         hid->dev.parent = &ghid->connection->bundle->dev;
 412 //      hid->bus = BUS_GREYBUS; /* Need a bustype for GREYBUS in <linux/input.h> */
 413
 414         /* Set HID device's name */
 415         snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
 416                  dev_name(&ghid->connection->bundle->dev),
 417                  hid->vendor, hid->product);
 418
 419         return 0;
 420 }
 421
 422 static int gb_hid_probe(struct gb_bundle *bundle,
 423                         const struct greybus_bundle_id *id)
 424 {
 425         struct greybus_descriptor_cport *cport_desc;
 426         struct gb_connection *connection;
 427         struct hid_device *hid;
 428         struct gb_hid *ghid;
 429         int ret;
 430
 431         if (bundle->num_cports != 1)
 432                 return -ENODEV;
 433
 434         cport_desc = &bundle->cport_desc[0];
 435         if (cport_desc->protocol_id != GREYBUS_PROTOCOL_HID)
 436                 return -ENODEV;
 437
 438         ghid = kzalloc(sizeof(*ghid), GFP_KERNEL);
 439         if (!ghid)
 440                 return -ENOMEM;
 441
 442         connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
 443                                                 gb_hid_request_handler);
 444         if (IS_ERR(connection)) {
 445                 ret = PTR_ERR(connection);
 446                 goto err_free_ghid;
 447         }
 448
 449         gb_connection_set_data(connection, ghid);
 450         ghid->connection = connection;
 451
 452         hid = hid_allocate_device();
 453         if (IS_ERR(hid)) {
 454                 ret = PTR_ERR(hid);
 455                 goto err_connection_destroy;
 456         }
 457
 458         ghid->hid = hid;
 459         ghid->bundle = bundle;
 460
 461         greybus_set_drvdata(bundle, ghid);
 462
 463         ret = gb_connection_enable(connection);
 464         if (ret)
 465                 goto err_destroy_hid;
 466
 467         ret = gb_hid_init(ghid);
 468         if (ret)
 469                 goto err_connection_disable;
 470
 471         ret = hid_add_device(hid);
 472         if (ret) {
 473                 hid_err(hid, "can't add hid device: %d\n", ret);
 474                 goto err_connection_disable;
 475         }
 476
 477         gb_pm_runtime_put_autosuspend(bundle);
 478
 479         return 0;
 480
 481 err_connection_disable:
 482         gb_connection_disable(connection);
 483 err_destroy_hid:
 484         hid_destroy_device(hid);
 485 err_connection_destroy:
 486         gb_connection_destroy(connection);
 487 err_free_ghid:
 488         kfree(ghid);
 489
 490         return ret;
 491 }
 492
 493 static void gb_hid_disconnect(struct gb_bundle *bundle)
 494 {
 495         struct gb_hid *ghid = greybus_get_drvdata(bundle);
 496
 497         if (gb_pm_runtime_get_sync(bundle))
 498                 gb_pm_runtime_get_noresume(bundle);
 499
 500         hid_destroy_device(ghid->hid);
 501         gb_connection_disable(ghid->connection);
 502         gb_connection_destroy(ghid->connection);
 503         kfree(ghid);
 504 }
 505
 506 static const struct greybus_bundle_id gb_hid_id_table[] = {
 507         { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_HID) },
 508         { }
 509 };
 510 MODULE_DEVICE_TABLE(greybus, gb_hid_id_table);
 511
 512 static struct greybus_driver gb_hid_driver = {
 513         .name           = "hid",
 514         .probe          = gb_hid_probe,
 515         .disconnect     = gb_hid_disconnect,
 516         .id_table       = gb_hid_id_table,
 517 };
 518 module_greybus_driver(gb_hid_driver);
 519
 520 MODULE_LICENSE("GPL v2");