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