drivers/media/rc/ir_toy.c

   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
  25 static const u8 COMMAND_VERSION[] = { 'v' };
  26 // End transmit and repeat reset command so we exit sump mode
  27 static const u8 COMMAND_RESET[] = { 0xff, 0xff, 0, 0, 0, 0, 0 };
  28 static const u8 COMMAND_SMODE_ENTER[] = { 's' };
  29 static const u8 COMMAND_SMODE_EXIT[] = { 0 };
  30 static 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
  49 enum state {
  50         STATE_IRDATA,
  51         STATE_COMMAND_NO_RESP,
  52         STATE_COMMAND,
  53         STATE_TX,
  54 };
  55
  56 struct 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
  81 static 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
 200 static 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
 212 static 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
 237 static 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
 262 static 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  */
 301 static 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
 368 static 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
 389 static 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                 goto free_rcdev;
 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
 514 free_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);
 520 free_irtoy:
 521         kfree(irtoy->in);
 522         kfree(irtoy->out);
 523         kfree(irtoy);
 524         return err;
 525 }
 526
 527 static 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
 542 static 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
 548 static struct usb_driver irtoy_driver = {
 549         .name = KBUILD_MODNAME,
 550         .probe = irtoy_probe,
 551         .disconnect = irtoy_disconnect,
 552         .id_table = irtoy_table,
 553 };
 554
 555 module_usb_driver(irtoy_driver);
 556
 557 MODULE_AUTHOR("Sean Young <sean@mess.org>");
 558 MODULE_DESCRIPTION("Infrared Toy and IR Droid driver");
 559 MODULE_LICENSE("GPL");
 560 MODULE_DEVICE_TABLE(usb, irtoy_table);