linux/drivers/media/rc/ir_toy.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2
   3/*
   4 * Infrared Toy and IR Droid RC core driver
   5 *
   6 * Copyright (C) 2020 Sean Young <sean@mess.org>
   7 *
   8 * http://dangerousprototypes.com/docs/USB_IR_Toy:_Sampling_mode
   9 *
  10 * This driver is based on the lirc driver which can be found here:
  11 * https://sourceforge.net/p/lirc/git/ci/master/tree/plugins/irtoy.c
  12 * Copyright (C) 2011 Peter Kooiman <pkooiman@gmail.com>
  13 */
  14
  15#include <asm/unaligned.h>
  16#include <linux/completion.h>
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/usb.h>
  20#include <linux/slab.h>
  21#include <linux/usb/input.h>
  22
  23#include <media/rc-core.h>
  24
  25static const u8 COMMAND_VERSION[] = { 'v' };
  26// End transmit and repeat reset command so we exit sump mode
  27static const u8 COMMAND_RESET[] = { 0xff, 0xff, 0, 0, 0, 0, 0 };
  28static const u8 COMMAND_SMODE_ENTER[] = { 's' };
  29static const u8 COMMAND_SMODE_EXIT[] = { 0 };
  30static const u8 COMMAND_TXSTART[] = { 0x26, 0x24, 0x25, 0x03 };
  31
  32#define REPLY_XMITCOUNT 't'
  33#define REPLY_XMITSUCCESS 'C'
  34#define REPLY_VERSION 'V'
  35#define REPLY_SAMPLEMODEPROTO 'S'
  36
  37#define TIMEOUT 500
  38
  39#define LEN_XMITRES 3
  40#define LEN_VERSION 4
  41#define LEN_SAMPLEMODEPROTO 3
  42
  43#define MIN_FW_VERSION 20
  44#define UNIT_US 21
  45#define MAX_TIMEOUT_US (UNIT_US * U16_MAX)
  46
  47#define MAX_PACKET 64
  48
  49enum state {
  50        STATE_IRDATA,
  51        STATE_COMMAND_NO_RESP,
  52        STATE_COMMAND,
  53        STATE_TX,
  54};
  55
  56struct irtoy {
  57        struct device *dev;
  58        struct usb_device *usbdev;
  59
  60        struct rc_dev *rc;
  61        struct urb *urb_in, *urb_out;
  62
  63        u8 *in;
  64        u8 *out;
  65        struct completion command_done;
  66
  67        bool pulse;
  68        enum state state;
  69
  70        void *tx_buf;
  71        uint tx_len;
  72
  73        uint emitted;
  74        uint hw_version;
  75        uint sw_version;
  76        uint proto_version;
  77
  78        char phys[64];
  79};
  80
  81static void irtoy_response(struct irtoy *irtoy, u32 len)
  82{
  83        switch (irtoy->state) {
  84        case STATE_COMMAND:
  85                if (len == LEN_VERSION && irtoy->in[0] == REPLY_VERSION) {
  86                        uint version;
  87
  88                        irtoy->in[LEN_VERSION] = 0;
  89
  90                        if (kstrtouint(irtoy->in + 1, 10, &version)) {
  91                                dev_err(irtoy->dev, "invalid version %*phN. Please make sure you are using firmware v20 or higher",
  92                                        LEN_VERSION, irtoy->in);
  93                                break;
  94                        }
  95
  96                        dev_dbg(irtoy->dev, "version %s\n", irtoy->in);
  97
  98                        irtoy->hw_version = version / 100;
  99                        irtoy->sw_version = version % 100;
 100
 101                        irtoy->state = STATE_IRDATA;
 102                        complete(&irtoy->command_done);
 103                } else if (len == LEN_SAMPLEMODEPROTO &&
 104                           irtoy->in[0] == REPLY_SAMPLEMODEPROTO) {
 105                        uint version;
 106
 107                        irtoy->in[LEN_SAMPLEMODEPROTO] = 0;
 108
 109                        if (kstrtouint(irtoy->in + 1, 10, &version)) {
 110                                dev_err(irtoy->dev, "invalid sample mode response %*phN",
 111                                        LEN_SAMPLEMODEPROTO, irtoy->in);
 112                                return;
 113                        }
 114
 115                        dev_dbg(irtoy->dev, "protocol %s\n", irtoy->in);
 116
 117                        irtoy->proto_version = version;
 118
 119                        irtoy->state = STATE_IRDATA;
 120                        complete(&irtoy->command_done);
 121                } else {
 122                        dev_err(irtoy->dev, "unexpected response to command: %*phN\n",
 123                                len, irtoy->in);
 124                }
 125                break;
 126        case STATE_COMMAND_NO_RESP:
 127        case STATE_IRDATA: {
 128                struct ir_raw_event rawir = { .pulse = irtoy->pulse };
 129                __be16 *in = (__be16 *)irtoy->in;
 130                int i;
 131
 132                for (i = 0; i < len / sizeof(__be16); i++) {
 133                        u16 v = be16_to_cpu(in[i]);
 134
 135                        if (v == 0xffff) {
 136                                rawir.pulse = false;
 137                        } else {
 138                                rawir.duration = v * UNIT_US;
 139                                ir_raw_event_store_with_timeout(irtoy->rc,
 140                                                                &rawir);
 141                        }
 142
 143                        rawir.pulse = !rawir.pulse;
 144                }
 145
 146                irtoy->pulse = rawir.pulse;
 147
 148                ir_raw_event_handle(irtoy->rc);
 149                break;
 150        }
 151        case STATE_TX:
 152                if (irtoy->tx_len == 0) {
 153                        if (len == LEN_XMITRES &&
 154                            irtoy->in[0] == REPLY_XMITCOUNT) {
 155                                u16 emitted = get_unaligned_be16(irtoy->in + 1);
 156
 157                                dev_dbg(irtoy->dev, "emitted:%u\n", emitted);
 158
 159                                irtoy->emitted = emitted;
 160                        } else if (len == 1 &&
 161                                   irtoy->in[0] == REPLY_XMITSUCCESS) {
 162                                irtoy->state = STATE_IRDATA;
 163                                complete(&irtoy->command_done);
 164                        }
 165                } else {
 166                        // send next part of tx buffer
 167                        uint space = irtoy->in[0];
 168                        uint buf_len;
 169                        int err;
 170
 171                        if (len != 1 || space > MAX_PACKET || space == 0) {
 172                                dev_dbg(irtoy->dev, "packet length expected: %*phN\n",
 173                                        len, irtoy->in);
 174                                break;
 175                        }
 176
 177                        buf_len = min(space, irtoy->tx_len);
 178
 179                        dev_dbg(irtoy->dev, "remaining:%u sending:%u\n",
 180                                irtoy->tx_len, buf_len);
 181
 182                        memcpy(irtoy->out, irtoy->tx_buf, buf_len);
 183                        irtoy->urb_out->transfer_buffer_length = buf_len;
 184                        err = usb_submit_urb(irtoy->urb_out, GFP_ATOMIC);
 185                        if (err != 0) {
 186                                dev_err(irtoy->dev, "fail to submit tx buf urb: %d\n",
 187                                        err);
 188                                irtoy->state = STATE_IRDATA;
 189                                complete(&irtoy->command_done);
 190                                break;
 191                        }
 192
 193                        irtoy->tx_buf += buf_len;
 194                        irtoy->tx_len -= buf_len;
 195                }
 196                break;
 197        }
 198}
 199
 200static void irtoy_out_callback(struct urb *urb)
 201{
 202        struct irtoy *irtoy = urb->context;
 203
 204        if (urb->status == 0) {
 205                if (irtoy->state == STATE_COMMAND_NO_RESP)
 206                        complete(&irtoy->command_done);
 207        } else {
 208                dev_warn(irtoy->dev, "out urb status: %d\n", urb->status);
 209        }
 210}
 211
 212static void irtoy_in_callback(struct urb *urb)
 213{
 214        struct irtoy *irtoy = urb->context;
 215        int ret;
 216
 217        switch (urb->status) {
 218        case 0:
 219                irtoy_response(irtoy, urb->actual_length);
 220                break;
 221        case -ECONNRESET:
 222        case -ENOENT:
 223        case -ESHUTDOWN:
 224        case -EPROTO:
 225        case -EPIPE:
 226                usb_unlink_urb(urb);
 227                return;
 228        default:
 229                dev_dbg(irtoy->dev, "in urb status: %d\n", urb->status);
 230        }
 231
 232        ret = usb_submit_urb(urb, GFP_ATOMIC);
 233        if (ret && ret != -ENODEV)
 234                dev_warn(irtoy->dev, "failed to resubmit urb: %d\n", ret);
 235}
 236
 237static int irtoy_command(struct irtoy *irtoy, const u8 *cmd, int cmd_len,
 238                         enum state state)
 239{
 240        int err;
 241
 242        init_completion(&irtoy->command_done);
 243
 244        irtoy->state = state;
 245
 246        memcpy(irtoy->out, cmd, cmd_len);
 247        irtoy->urb_out->transfer_buffer_length = cmd_len;
 248
 249        err = usb_submit_urb(irtoy->urb_out, GFP_KERNEL);
 250        if (err != 0)
 251                return err;
 252
 253        if (!wait_for_completion_timeout(&irtoy->command_done,
 254                                         msecs_to_jiffies(TIMEOUT))) {
 255                usb_kill_urb(irtoy->urb_out);
 256                return -ETIMEDOUT;
 257        }
 258
 259        return 0;
 260}
 261
 262static int irtoy_setup(struct irtoy *irtoy)
 263{
 264        int err;
 265
 266        err = irtoy_command(irtoy, COMMAND_RESET, sizeof(COMMAND_RESET),
 267                            STATE_COMMAND_NO_RESP);
 268        if (err != 0) {
 269                dev_err(irtoy->dev, "could not write reset command: %d\n",
 270                        err);
 271                return err;
 272        }
 273
 274        usleep_range(50, 50);
 275
 276        // get version
 277        err = irtoy_command(irtoy, COMMAND_VERSION, sizeof(COMMAND_VERSION),
 278                            STATE_COMMAND);
 279        if (err) {
 280                dev_err(irtoy->dev, "could not write version command: %d\n",
 281                        err);
 282                return err;
 283        }
 284
 285        // enter sample mode
 286        err = irtoy_command(irtoy, COMMAND_SMODE_ENTER,
 287                            sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND);
 288        if (err)
 289                dev_err(irtoy->dev, "could not write sample command: %d\n",
 290                        err);
 291
 292        return err;
 293}
 294
 295/*
 296 * When sending IR, it is imperative that we send the IR data as quickly
 297 * as possible to the device, so it does not run out of IR data and
 298 * introduce gaps. Allocate the buffer here, and then feed the data from
 299 * the urb callback handler.
 300 */
 301static int irtoy_tx(struct rc_dev *rc, uint *txbuf, uint count)
 302{
 303        struct irtoy *irtoy = rc->priv;
 304        unsigned int i, size;
 305        __be16 *buf;
 306        int err;
 307
 308        size = sizeof(u16) * (count + 1);
 309        buf = kmalloc(size, GFP_KERNEL);
 310        if (!buf)
 311                return -ENOMEM;
 312
 313        for (i = 0; i < count; i++) {
 314                u16 v = DIV_ROUND_CLOSEST(txbuf[i], UNIT_US);
 315
 316                if (!v)
 317                        v = 1;
 318                buf[i] = cpu_to_be16(v);
 319        }
 320
 321        buf[count] = cpu_to_be16(0xffff);
 322
 323        irtoy->tx_buf = buf;
 324        irtoy->tx_len = size;
 325        irtoy->emitted = 0;
 326
 327        // There is an issue where if the unit is receiving IR while the
 328        // first TXSTART command is sent, the device might end up hanging
 329        // with its led on. It does not respond to any command when this
 330        // happens. To work around this, re-enter sample mode.
 331        err = irtoy_command(irtoy, COMMAND_SMODE_EXIT,
 332                            sizeof(COMMAND_SMODE_EXIT), STATE_COMMAND_NO_RESP);
 333        if (err) {
 334                dev_err(irtoy->dev, "exit sample mode: %d\n", err);
 335                return err;
 336        }
 337
 338        err = irtoy_command(irtoy, COMMAND_SMODE_ENTER,
 339                            sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND);
 340        if (err) {
 341                dev_err(irtoy->dev, "enter sample mode: %d\n", err);
 342                return err;
 343        }
 344
 345        err = irtoy_command(irtoy, COMMAND_TXSTART, sizeof(COMMAND_TXSTART),
 346                            STATE_TX);
 347        kfree(buf);
 348
 349        if (err) {
 350                dev_err(irtoy->dev, "failed to send tx start command: %d\n",
 351                        err);
 352                // not sure what state the device is in, reset it
 353                irtoy_setup(irtoy);
 354                return err;
 355        }
 356
 357        if (size != irtoy->emitted) {
 358                dev_err(irtoy->dev, "expected %u emitted, got %u\n", size,
 359                        irtoy->emitted);
 360                // not sure what state the device is in, reset it
 361                irtoy_setup(irtoy);
 362                return -EINVAL;
 363        }
 364
 365        return count;
 366}
 367
 368static int irtoy_tx_carrier(struct rc_dev *rc, uint32_t carrier)
 369{
 370        struct irtoy *irtoy = rc->priv;
 371        u8 buf[3];
 372        int err;
 373
 374        if (carrier < 11800)
 375                return -EINVAL;
 376
 377        buf[0] = 0x06;
 378        buf[1] = DIV_ROUND_CLOSEST(48000000, 16 * carrier) - 1;
 379        buf[2] = 0;
 380
 381        err = irtoy_command(irtoy, buf, sizeof(buf), STATE_COMMAND_NO_RESP);
 382        if (err)
 383                dev_err(irtoy->dev, "could not write carrier command: %d\n",
 384                        err);
 385
 386        return err;
 387}
 388
 389static int irtoy_probe(struct usb_interface *intf,
 390                       const struct usb_device_id *id)
 391{
 392        struct usb_host_interface *idesc = intf->cur_altsetting;
 393        struct usb_device *usbdev = interface_to_usbdev(intf);
 394        struct usb_endpoint_descriptor *ep_in = NULL;
 395        struct usb_endpoint_descriptor *ep_out = NULL;
 396        struct usb_endpoint_descriptor *ep = NULL;
 397        struct irtoy *irtoy;
 398        struct rc_dev *rc;
 399        struct urb *urb;
 400        int i, pipe, err = -ENOMEM;
 401
 402        for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
 403                ep = &idesc->endpoint[i].desc;
 404
 405                if (!ep_in && usb_endpoint_is_bulk_in(ep) &&
 406                    usb_endpoint_maxp(ep) == MAX_PACKET)
 407                        ep_in = ep;
 408
 409                if (!ep_out && usb_endpoint_is_bulk_out(ep) &&
 410                    usb_endpoint_maxp(ep) == MAX_PACKET)
 411                        ep_out = ep;
 412        }
 413
 414        if (!ep_in || !ep_out) {
 415                dev_err(&intf->dev, "required endpoints not found\n");
 416                return -ENODEV;
 417        }
 418
 419        irtoy = kzalloc(sizeof(*irtoy), GFP_KERNEL);
 420        if (!irtoy)
 421                return -ENOMEM;
 422
 423        irtoy->in = kmalloc(MAX_PACKET,  GFP_KERNEL);
 424        if (!irtoy->in)
 425                goto free_irtoy;
 426
 427        irtoy->out = kmalloc(MAX_PACKET,  GFP_KERNEL);
 428        if (!irtoy->out)
 429                goto free_irtoy;
 430
 431        rc = rc_allocate_device(RC_DRIVER_IR_RAW);
 432        if (!rc)
 433                goto free_irtoy;
 434
 435        urb = usb_alloc_urb(0, GFP_KERNEL);
 436        if (!urb)
 437                goto free_rcdev;
 438
 439        pipe = usb_rcvbulkpipe(usbdev, ep_in->bEndpointAddress);
 440        usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->in, MAX_PACKET,
 441                          irtoy_in_callback, irtoy);
 442        irtoy->urb_in = urb;
 443
 444        urb = usb_alloc_urb(0, GFP_KERNEL);
 445        if (!urb)
 446                goto free_rcdev;
 447
 448        pipe = usb_sndbulkpipe(usbdev, ep_out->bEndpointAddress);
 449        usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->out, MAX_PACKET,
 450                          irtoy_out_callback, irtoy);
 451
 452        irtoy->dev = &intf->dev;
 453        irtoy->usbdev = usbdev;
 454        irtoy->rc = rc;
 455        irtoy->urb_out = urb;
 456        irtoy->pulse = true;
 457
 458        err = usb_submit_urb(irtoy->urb_in, GFP_KERNEL);
 459        if (err != 0) {
 460                dev_err(irtoy->dev, "fail to submit in urb: %d\n", err);
 461                return err;
 462        }
 463
 464        err = irtoy_setup(irtoy);
 465        if (err)
 466                goto free_rcdev;
 467
 468        dev_info(irtoy->dev, "version: hardware %u, firmware %u.%u, protocol %u",
 469                 irtoy->hw_version, irtoy->sw_version / 10,
 470                 irtoy->sw_version % 10, irtoy->proto_version);
 471
 472        if (irtoy->sw_version < MIN_FW_VERSION) {
 473                dev_err(irtoy->dev, "need firmware V%02u or higher",
 474                        MIN_FW_VERSION);
 475                err = -ENODEV;
 476                goto free_rcdev;
 477        }
 478
 479        usb_make_path(usbdev, irtoy->phys, sizeof(irtoy->phys));
 480
 481        rc->device_name = "Infrared Toy";
 482        rc->driver_name = KBUILD_MODNAME;
 483        rc->input_phys = irtoy->phys;
 484        usb_to_input_id(usbdev, &rc->input_id);
 485        rc->dev.parent = &intf->dev;
 486        rc->priv = irtoy;
 487        rc->tx_ir = irtoy_tx;
 488        rc->s_tx_carrier = irtoy_tx_carrier;
 489        rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 490        rc->map_name = RC_MAP_RC6_MCE;
 491        rc->rx_resolution = UNIT_US;
 492        rc->timeout = IR_DEFAULT_TIMEOUT;
 493
 494        /*
 495         * end of transmission is detected by absence of a usb packet
 496         * with more pulse/spaces. However, each usb packet sent can
 497         * contain 32 pulse/spaces, which can be quite lengthy, so there
 498         * can be a delay between usb packets. For example with nec there is a
 499         * 17ms gap between packets.
 500         *
 501         * So, make timeout a largish minimum which works with most protocols.
 502         */
 503        rc->min_timeout = MS_TO_US(40);
 504        rc->max_timeout = MAX_TIMEOUT_US;
 505
 506        err = rc_register_device(rc);
 507        if (err)
 508                goto free_rcdev;
 509
 510        usb_set_intfdata(intf, irtoy);
 511
 512        return 0;
 513
 514free_rcdev:
 515        usb_kill_urb(irtoy->urb_out);
 516        usb_free_urb(irtoy->urb_out);
 517        usb_kill_urb(irtoy->urb_in);
 518        usb_free_urb(irtoy->urb_in);
 519        rc_free_device(rc);
 520free_irtoy:
 521        kfree(irtoy->in);
 522        kfree(irtoy->out);
 523        kfree(irtoy);
 524        return err;
 525}
 526
 527static void irtoy_disconnect(struct usb_interface *intf)
 528{
 529        struct irtoy *ir = usb_get_intfdata(intf);
 530
 531        rc_unregister_device(ir->rc);
 532        usb_set_intfdata(intf, NULL);
 533        usb_kill_urb(ir->urb_out);
 534        usb_free_urb(ir->urb_out);
 535        usb_kill_urb(ir->urb_in);
 536        usb_free_urb(ir->urb_in);
 537        kfree(ir->in);
 538        kfree(ir->out);
 539        kfree(ir);
 540}
 541
 542static const struct usb_device_id irtoy_table[] = {
 543        { USB_DEVICE_INTERFACE_CLASS(0x04d8, 0xfd08, USB_CLASS_CDC_DATA) },
 544        { USB_DEVICE_INTERFACE_CLASS(0x04d8, 0xf58b, USB_CLASS_CDC_DATA) },
 545        { }
 546};
 547
 548static struct usb_driver irtoy_driver = {
 549        .name = KBUILD_MODNAME,
 550        .probe = irtoy_probe,
 551        .disconnect = irtoy_disconnect,
 552        .id_table = irtoy_table,
 553};
 554
 555module_usb_driver(irtoy_driver);
 556
 557MODULE_AUTHOR("Sean Young <sean@mess.org>");
 558MODULE_DESCRIPTION("Infrared Toy and IR Droid driver");
 559MODULE_LICENSE("GPL");
 560MODULE_DEVICE_TABLE(usb, irtoy_table);
 561