drivers/mfd/rave-sp.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 /*
   4  * Multifunction core driver for Zodiac Inflight Innovations RAVE
   5  * Supervisory Processor(SP) MCU that is connected via dedicated UART
   6  * port
   7  *
   8  * Copyright (C) 2017 Zodiac Inflight Innovations
   9  */
  10
  11 #include <linux/atomic.h>
  12 #include <linux/crc-ccitt.h>
  13 #include <linux/delay.h>
  14 #include <linux/export.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mfd/rave-sp.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/sched.h>
  23 #include <linux/serdev.h>
  24 #include <asm/unaligned.h>
  25
  26 /*
  27  * UART protocol using following entities:
  28  *  - message to MCU => ACK response
  29  *  - event from MCU => event ACK
  30  *
  31  * Frame structure:
  32  * <STX> <DATA> <CHECKSUM> <ETX>
  33  * Where:
  34  * - STX - is start of transmission character
  35  * - ETX - end of transmission
  36  * - DATA - payload
  37  * - CHECKSUM - checksum calculated on <DATA>
  38  *
  39  * If <DATA> or <CHECKSUM> contain one of control characters, then it is
  40  * escaped using <DLE> control code. Added <DLE> does not participate in
  41  * checksum calculation.
  42  */
  43 #define RAVE_SP_STX                     0x02
  44 #define RAVE_SP_ETX                     0x03
  45 #define RAVE_SP_DLE                     0x10
  46
  47 #define RAVE_SP_MAX_DATA_SIZE           64
  48 #define RAVE_SP_CHECKSUM_8B2C           1
  49 #define RAVE_SP_CHECKSUM_CCITT          2
  50 #define RAVE_SP_CHECKSUM_SIZE           RAVE_SP_CHECKSUM_CCITT
  51 /*
  52  * We don't store STX, ETX and unescaped bytes, so Rx is only
  53  * DATA + CSUM
  54  */
  55 #define RAVE_SP_RX_BUFFER_SIZE                          \
  56         (RAVE_SP_MAX_DATA_SIZE + RAVE_SP_CHECKSUM_SIZE)
  57
  58 #define RAVE_SP_STX_ETX_SIZE            2
  59 /*
  60  * For Tx we have to have space for everything, STX, EXT and
  61  * potentially stuffed DATA + CSUM data + csum
  62  */
  63 #define RAVE_SP_TX_BUFFER_SIZE                          \
  64         (RAVE_SP_STX_ETX_SIZE + 2 * RAVE_SP_RX_BUFFER_SIZE)
  65
  66 #define RAVE_SP_BOOT_SOURCE_GET         0
  67 #define RAVE_SP_BOOT_SOURCE_SET         1
  68
  69 #define RAVE_SP_RDU2_BOARD_TYPE_RMB     0
  70 #define RAVE_SP_RDU2_BOARD_TYPE_DEB     1
  71
  72 #define RAVE_SP_BOOT_SOURCE_SD          0
  73 #define RAVE_SP_BOOT_SOURCE_EMMC        1
  74 #define RAVE_SP_BOOT_SOURCE_NOR         2
  75
  76 /**
  77  * enum rave_sp_deframer_state - Possible state for de-framer
  78  *
  79  * @RAVE_SP_EXPECT_SOF:          Scanning input for start-of-frame marker
  80  * @RAVE_SP_EXPECT_DATA:         Got start of frame marker, collecting frame
  81  * @RAVE_SP_EXPECT_ESCAPED_DATA: Got escape character, collecting escaped byte
  82  */
  83 enum rave_sp_deframer_state {
  84         RAVE_SP_EXPECT_SOF,
  85         RAVE_SP_EXPECT_DATA,
  86         RAVE_SP_EXPECT_ESCAPED_DATA,
  87 };
  88
  89 /**
  90  * struct rave_sp_deframer - Device protocol deframer
  91  *
  92  * @state:  Current state of the deframer
  93  * @data:   Buffer used to collect deframed data
  94  * @length: Number of bytes de-framed so far
  95  */
  96 struct rave_sp_deframer {
  97         enum rave_sp_deframer_state state;
  98         unsigned char data[RAVE_SP_RX_BUFFER_SIZE];
  99         size_t length;
 100 };
 101
 102 /**
 103  * struct rave_sp_reply - Reply as per RAVE device protocol
 104  *
 105  * @length:     Expected reply length
 106  * @data:       Buffer to store reply payload in
 107  * @code:       Expected reply code
 108  * @ackid:      Expected reply ACK ID
 109  * @completion: Successful reply reception completion
 110  */
 111 struct rave_sp_reply {
 112         size_t length;
 113         void  *data;
 114         u8     code;
 115         u8     ackid;
 116         struct completion received;
 117 };
 118
 119 /**
 120  * struct rave_sp_checksum - Variant specific checksum implementation details
 121  *
 122  * @length:     Caculated checksum length
 123  * @subroutine: Utilized checksum algorithm implementation
 124  */
 125 struct rave_sp_checksum {
 126         size_t length;
 127         void (*subroutine)(const u8 *, size_t, u8 *);
 128 };
 129
 130 /**
 131  * struct rave_sp_variant_cmds - Variant specific command routines
 132  *
 133  * @translate:  Generic to variant specific command mapping routine
 134  *
 135  */
 136 struct rave_sp_variant_cmds {
 137         int (*translate)(enum rave_sp_command);
 138 };
 139
 140 /**
 141  * struct rave_sp_variant - RAVE supervisory processor core variant
 142  *
 143  * @checksum:   Variant specific checksum implementation
 144  * @cmd:        Variant specific command pointer table
 145  *
 146  */
 147 struct rave_sp_variant {
 148         const struct rave_sp_checksum *checksum;
 149         struct rave_sp_variant_cmds cmd;
 150 };
 151
 152 /**
 153  * struct rave_sp - RAVE supervisory processor core
 154  *
 155  * @serdev:                     Pointer to underlying serdev
 156  * @deframer:                   Stored state of the protocol deframer
 157  * @ackid:                      ACK ID used in last reply sent to the device
 158  * @bus_lock:                   Lock to serialize access to the device
 159  * @reply_lock:                 Lock protecting @reply
 160  * @reply:                      Pointer to memory to store reply payload
 161  *
 162  * @variant:                    Device variant specific information
 163  * @event_notifier_list:        Input event notification chain
 164  *
 165  * @part_number_firmware:       Firmware version
 166  * @part_number_bootloader:     Bootloader version
 167  */
 168 struct rave_sp {
 169         struct serdev_device *serdev;
 170         struct rave_sp_deframer deframer;
 171         atomic_t ackid;
 172         struct mutex bus_lock;
 173         struct mutex reply_lock;
 174         struct rave_sp_reply *reply;
 175
 176         const struct rave_sp_variant *variant;
 177         struct blocking_notifier_head event_notifier_list;
 178
 179         const char *part_number_firmware;
 180         const char *part_number_bootloader;
 181 };
 182
 183 struct rave_sp_version {
 184         u8     hardware;
 185         __le16 major;
 186         u8     minor;
 187         u8     letter[2];
 188 } __packed;
 189
 190 struct rave_sp_status {
 191         struct rave_sp_version bootloader_version;
 192         struct rave_sp_version firmware_version;
 193         u16 rdu_eeprom_flag;
 194         u16 dds_eeprom_flag;
 195         u8  pic_flag;
 196         u8  orientation;
 197         u32 etc;
 198         s16 temp[2];
 199         u8  backlight_current[3];
 200         u8  dip_switch;
 201         u8  host_interrupt;
 202         u16 voltage_28;
 203         u8  i2c_device_status;
 204         u8  power_status;
 205         u8  general_status;
 206         u8  deprecated1;
 207         u8  power_led_status;
 208         u8  deprecated2;
 209         u8  periph_power_shutoff;
 210 } __packed;
 211
 212 static bool rave_sp_id_is_event(u8 code)
 213 {
 214         return (code & 0xF0) == RAVE_SP_EVNT_BASE;
 215 }
 216
 217 static void rave_sp_unregister_event_notifier(struct device *dev, void *res)
 218 {
 219         struct rave_sp *sp = dev_get_drvdata(dev->parent);
 220         struct notifier_block *nb = *(struct notifier_block **)res;
 221         struct blocking_notifier_head *bnh = &sp->event_notifier_list;
 222
 223         WARN_ON(blocking_notifier_chain_unregister(bnh, nb));
 224 }
 225
 226 int devm_rave_sp_register_event_notifier(struct device *dev,
 227                                          struct notifier_block *nb)
 228 {
 229         struct rave_sp *sp = dev_get_drvdata(dev->parent);
 230         struct notifier_block **rcnb;
 231         int ret;
 232
 233         rcnb = devres_alloc(rave_sp_unregister_event_notifier,
 234                             sizeof(*rcnb), GFP_KERNEL);
 235         if (!rcnb)
 236                 return -ENOMEM;
 237
 238         ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
 239         if (!ret) {
 240                 *rcnb = nb;
 241                 devres_add(dev, rcnb);
 242         } else {
 243                 devres_free(rcnb);
 244         }
 245
 246         return ret;
 247 }
 248 EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
 249
 250 static void csum_8b2c(const u8 *buf, size_t size, u8 *crc)
 251 {
 252         *crc = *buf++;
 253         size--;
 254
 255         while (size--)
 256                 *crc += *buf++;
 257
 258         *crc = 1 + ~(*crc);
 259 }
 260
 261 static void csum_ccitt(const u8 *buf, size_t size, u8 *crc)
 262 {
 263         const u16 calculated = crc_ccitt_false(0xffff, buf, size);
 264
 265         /*
 266          * While the rest of the wire protocol is little-endian,
 267          * CCITT-16 CRC in RDU2 device is sent out in big-endian order.
 268          */
 269         put_unaligned_be16(calculated, crc);
 270 }
 271
 272 static void *stuff(unsigned char *dest, const unsigned char *src, size_t n)
 273 {
 274         while (n--) {
 275                 const unsigned char byte = *src++;
 276
 277                 switch (byte) {
 278                 case RAVE_SP_STX:
 279                 case RAVE_SP_ETX:
 280                 case RAVE_SP_DLE:
 281                         *dest++ = RAVE_SP_DLE;
 282                         /* FALLTHROUGH */
 283                 default:
 284                         *dest++ = byte;
 285                 }
 286         }
 287
 288         return dest;
 289 }
 290
 291 static int rave_sp_write(struct rave_sp *sp, const u8 *data, u8 data_size)
 292 {
 293         const size_t checksum_length = sp->variant->checksum->length;
 294         unsigned char frame[RAVE_SP_TX_BUFFER_SIZE];
 295         unsigned char crc[RAVE_SP_CHECKSUM_SIZE];
 296         unsigned char *dest = frame;
 297         size_t length;
 298
 299         if (WARN_ON(checksum_length > sizeof(crc)))
 300                 return -ENOMEM;
 301
 302         if (WARN_ON(data_size > sizeof(frame)))
 303                 return -ENOMEM;
 304
 305         sp->variant->checksum->subroutine(data, data_size, crc);
 306
 307         *dest++ = RAVE_SP_STX;
 308         dest = stuff(dest, data, data_size);
 309         dest = stuff(dest, crc, checksum_length);
 310         *dest++ = RAVE_SP_ETX;
 311
 312         length = dest - frame;
 313
 314         print_hex_dump_debug("rave-sp tx: ", DUMP_PREFIX_NONE,
 315                              16, 1, frame, length, false);
 316
 317         return serdev_device_write(sp->serdev, frame, length, HZ);
 318 }
 319
 320 static u8 rave_sp_reply_code(u8 command)
 321 {
 322         /*
 323          * There isn't a single rule that describes command code ->
 324          * ACK code transformation, but, going through various
 325          * versions of ICDs, there appear to be three distinct groups
 326          * that can be described by simple transformation.
 327          */
 328         switch (command) {
 329         case 0xA0 ... 0xBE:
 330                 /*
 331                  * Commands implemented by firmware found in RDU1 and
 332                  * older devices all seem to obey the following rule
 333                  */
 334                 return command + 0x20;
 335         case 0xE0 ... 0xEF:
 336                 /*
 337                  * Events emitted by all versions of the firmare use
 338                  * least significant bit to get an ACK code
 339                  */
 340                 return command | 0x01;
 341         default:
 342                 /*
 343                  * Commands implemented by firmware found in RDU2 are
 344                  * similar to "old" commands, but they use slightly
 345                  * different offset
 346                  */
 347                 return command + 0x40;
 348         }
 349 }
 350
 351 int rave_sp_exec(struct rave_sp *sp,
 352                  void *__data,  size_t data_size,
 353                  void *reply_data, size_t reply_data_size)
 354 {
 355         struct rave_sp_reply reply = {
 356                 .data     = reply_data,
 357                 .length   = reply_data_size,
 358                 .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
 359         };
 360         unsigned char *data = __data;
 361         int command, ret = 0;
 362         u8 ackid;
 363
 364         command = sp->variant->cmd.translate(data[0]);
 365         if (command < 0)
 366                 return command;
 367
 368         ackid       = atomic_inc_return(&sp->ackid);
 369         reply.ackid = ackid;
 370         reply.code  = rave_sp_reply_code((u8)command),
 371
 372         mutex_lock(&sp->bus_lock);
 373
 374         mutex_lock(&sp->reply_lock);
 375         sp->reply = &reply;
 376         mutex_unlock(&sp->reply_lock);
 377
 378         data[0] = command;
 379         data[1] = ackid;
 380
 381         rave_sp_write(sp, data, data_size);
 382
 383         if (!wait_for_completion_timeout(&reply.received, HZ)) {
 384                 dev_err(&sp->serdev->dev, "Command timeout\n");
 385                 ret = -ETIMEDOUT;
 386
 387                 mutex_lock(&sp->reply_lock);
 388                 sp->reply = NULL;
 389                 mutex_unlock(&sp->reply_lock);
 390         }
 391
 392         mutex_unlock(&sp->bus_lock);
 393         return ret;
 394 }
 395 EXPORT_SYMBOL_GPL(rave_sp_exec);
 396
 397 static void rave_sp_receive_event(struct rave_sp *sp,
 398                                   const unsigned char *data, size_t length)
 399 {
 400         u8 cmd[] = {
 401                 [0] = rave_sp_reply_code(data[0]),
 402                 [1] = data[1],
 403         };
 404
 405         rave_sp_write(sp, cmd, sizeof(cmd));
 406
 407         blocking_notifier_call_chain(&sp->event_notifier_list,
 408                                      rave_sp_action_pack(data[0], data[2]),
 409                                      NULL);
 410 }
 411
 412 static void rave_sp_receive_reply(struct rave_sp *sp,
 413                                   const unsigned char *data, size_t length)
 414 {
 415         struct device *dev = &sp->serdev->dev;
 416         struct rave_sp_reply *reply;
 417         const  size_t payload_length = length - 2;
 418
 419         mutex_lock(&sp->reply_lock);
 420         reply = sp->reply;
 421
 422         if (reply) {
 423                 if (reply->code == data[0] && reply->ackid == data[1] &&
 424                     payload_length >= reply->length) {
 425                         /*
 426                          * We are relying on memcpy(dst, src, 0) to be a no-op
 427                          * when handling commands that have a no-payload reply
 428                          */
 429                         memcpy(reply->data, &data[2], reply->length);
 430                         complete(&reply->received);
 431                         sp->reply = NULL;
 432                 } else {
 433                         dev_err(dev, "Ignoring incorrect reply\n");
 434                         dev_dbg(dev, "Code:   expected = 0x%08x received = 0x%08x\n",
 435                                 reply->code, data[0]);
 436                         dev_dbg(dev, "ACK ID: expected = 0x%08x received = 0x%08x\n",
 437                                 reply->ackid, data[1]);
 438                         dev_dbg(dev, "Length: expected = %zu received = %zu\n",
 439                                 reply->length, payload_length);
 440                 }
 441         }
 442
 443         mutex_unlock(&sp->reply_lock);
 444 }
 445
 446 static void rave_sp_receive_frame(struct rave_sp *sp,
 447                                   const unsigned char *data,
 448                                   size_t length)
 449 {
 450         const size_t checksum_length = sp->variant->checksum->length;
 451         const size_t payload_length  = length - checksum_length;
 452         const u8 *crc_reported       = &data[payload_length];
 453         struct device *dev           = &sp->serdev->dev;
 454         u8 crc_calculated[RAVE_SP_CHECKSUM_SIZE];
 455
 456         if (unlikely(checksum_length > sizeof(crc_calculated))) {
 457                 dev_warn(dev, "Checksum too long, dropping\n");
 458                 return;
 459         }
 460
 461         print_hex_dump_debug("rave-sp rx: ", DUMP_PREFIX_NONE,
 462                              16, 1, data, length, false);
 463
 464         if (unlikely(length <= checksum_length)) {
 465                 dev_warn(dev, "Dropping short frame\n");
 466                 return;
 467         }
 468
 469         sp->variant->checksum->subroutine(data, payload_length,
 470                                           crc_calculated);
 471
 472         if (memcmp(crc_calculated, crc_reported, checksum_length)) {
 473                 dev_warn(dev, "Dropping bad frame\n");
 474                 return;
 475         }
 476
 477         if (rave_sp_id_is_event(data[0]))
 478                 rave_sp_receive_event(sp, data, length);
 479         else
 480                 rave_sp_receive_reply(sp, data, length);
 481 }
 482
 483 static int rave_sp_receive_buf(struct serdev_device *serdev,
 484                                const unsigned char *buf, size_t size)
 485 {
 486         struct device *dev = &serdev->dev;
 487         struct rave_sp *sp = dev_get_drvdata(dev);
 488         struct rave_sp_deframer *deframer = &sp->deframer;
 489         const unsigned char *src = buf;
 490         const unsigned char *end = buf + size;
 491
 492         while (src < end) {
 493                 const unsigned char byte = *src++;
 494
 495                 switch (deframer->state) {
 496                 case RAVE_SP_EXPECT_SOF:
 497                         if (byte == RAVE_SP_STX)
 498                                 deframer->state = RAVE_SP_EXPECT_DATA;
 499                         break;
 500
 501                 case RAVE_SP_EXPECT_DATA:
 502                         /*
 503                          * Treat special byte values first
 504                          */
 505                         switch (byte) {
 506                         case RAVE_SP_ETX:
 507                                 rave_sp_receive_frame(sp,
 508                                                       deframer->data,
 509                                                       deframer->length);
 510                                 /*
 511                                  * Once we extracted a complete frame
 512                                  * out of a stream, we call it done
 513                                  * and proceed to bailing out while
 514                                  * resetting the framer to initial
 515                                  * state, regardless if we've consumed
 516                                  * all of the stream or not.
 517                                  */
 518                                 goto reset_framer;
 519                         case RAVE_SP_STX:
 520                                 dev_warn(dev, "Bad frame: STX before ETX\n");
 521                                 /*
 522                                  * If we encounter second "start of
 523                                  * the frame" marker before seeing
 524                                  * corresponding "end of frame", we
 525                                  * reset the framer and ignore both:
 526                                  * frame started by first SOF and
 527                                  * frame started by current SOF.
 528                                  *
 529                                  * NOTE: The above means that only the
 530                                  * frame started by third SOF, sent
 531                                  * after this one will have a chance
 532                                  * to get throught.
 533                                  */
 534                                 goto reset_framer;
 535                         case RAVE_SP_DLE:
 536                                 deframer->state = RAVE_SP_EXPECT_ESCAPED_DATA;
 537                                 /*
 538                                  * If we encounter escape sequence we
 539                                  * need to skip it and collect the
 540                                  * byte that follows. We do it by
 541                                  * forcing the next iteration of the
 542                                  * encompassing while loop.
 543                                  */
 544                                 continue;
 545                         }
 546                         /*
 547                          * For the rest of the bytes, that are not
 548                          * speical snoflakes, we do the same thing
 549                          * that we do to escaped data - collect it in
 550                          * deframer buffer
 551                          */
 552
 553                         /* FALLTHROUGH */
 554
 555                 case RAVE_SP_EXPECT_ESCAPED_DATA:
 556                         if (deframer->length == sizeof(deframer->data)) {
 557                                 dev_warn(dev, "Bad frame: Too long\n");
 558                                 /*
 559                                  * If the amount of data we've
 560                                  * accumulated for current frame so
 561                                  * far starts to exceed the capacity
 562                                  * of deframer's buffer, there's
 563                                  * nothing else we can do but to
 564                                  * discard that data and start
 565                                  * assemblying a new frame again
 566                                  */
 567                                 goto reset_framer;
 568                         }
 569
 570                         deframer->data[deframer->length++] = byte;
 571
 572                         /*
 573                          * We've extracted out special byte, now we
 574                          * can go back to regular data collecting
 575                          */
 576                         deframer->state = RAVE_SP_EXPECT_DATA;
 577                         break;
 578                 }
 579         }
 580
 581         /*
 582          * The only way to get out of the above loop and end up here
 583          * is throught consuming all of the supplied data, so here we
 584          * report that we processed it all.
 585          */
 586         return size;
 587
 588 reset_framer:
 589         /*
 590          * NOTE: A number of codepaths that will drop us here will do
 591          * so before consuming all 'size' bytes of the data passed by
 592          * serdev layer. We rely on the fact that serdev layer will
 593          * re-execute this handler with the remainder of the Rx bytes
 594          * once we report actual number of bytes that we processed.
 595          */
 596         deframer->state  = RAVE_SP_EXPECT_SOF;
 597         deframer->length = 0;
 598
 599         return src - buf;
 600 }
 601
 602 static int rave_sp_rdu1_cmd_translate(enum rave_sp_command command)
 603 {
 604         if (command >= RAVE_SP_CMD_STATUS &&
 605             command <= RAVE_SP_CMD_CONTROL_EVENTS)
 606                 return command;
 607
 608         return -EINVAL;
 609 }
 610
 611 static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command)
 612 {
 613         if (command >= RAVE_SP_CMD_GET_FIRMWARE_VERSION &&
 614             command <= RAVE_SP_CMD_GET_GPIO_STATE)
 615                 return command;
 616
 617         if (command == RAVE_SP_CMD_REQ_COPPER_REV) {
 618                 /*
 619                  * As per RDU2 ICD 3.4.47 CMD_GET_COPPER_REV code is
 620                  * different from that for RDU1 and it is set to 0x28.
 621                  */
 622                 return 0x28;
 623         }
 624
 625         return rave_sp_rdu1_cmd_translate(command);
 626 }
 627
 628 static int rave_sp_default_cmd_translate(enum rave_sp_command command)
 629 {
 630         /*
 631          * All of the following command codes were taken from "Table :
 632          * Communications Protocol Message Types" in section 3.3
 633          * "MESSAGE TYPES" of Rave PIC24 ICD.
 634          */
 635         switch (command) {
 636         case RAVE_SP_CMD_GET_FIRMWARE_VERSION:
 637                 return 0x11;
 638         case RAVE_SP_CMD_GET_BOOTLOADER_VERSION:
 639                 return 0x12;
 640         case RAVE_SP_CMD_BOOT_SOURCE:
 641                 return 0x14;
 642         case RAVE_SP_CMD_SW_WDT:
 643                 return 0x1C;
 644         case RAVE_SP_CMD_RESET:
 645                 return 0x1E;
 646         case RAVE_SP_CMD_RESET_REASON:
 647                 return 0x1F;
 648         default:
 649                 return -EINVAL;
 650         }
 651 }
 652
 653 static const char *devm_rave_sp_version(struct device *dev,
 654                                         struct rave_sp_version *version)
 655 {
 656         /*
 657          * NOTE: The format string below uses %02d to display u16
 658          * intentionally for the sake of backwards compatibility with
 659          * legacy software.
 660          */
 661         return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
 662                               version->hardware,
 663                               le16_to_cpu(version->major),
 664                               version->minor,
 665                               version->letter[0],
 666                               version->letter[1]);
 667 }
 668
 669 static int rave_sp_get_status(struct rave_sp *sp)
 670 {
 671         struct device *dev = &sp->serdev->dev;
 672         u8 cmd[] = {
 673                 [0] = RAVE_SP_CMD_STATUS,
 674                 [1] = 0
 675         };
 676         struct rave_sp_status status;
 677         const char *version;
 678         int ret;
 679
 680         ret = rave_sp_exec(sp, cmd, sizeof(cmd), &status, sizeof(status));
 681         if (ret)
 682                 return ret;
 683
 684         version = devm_rave_sp_version(dev, &status.firmware_version);
 685         if (!version)
 686                 return -ENOMEM;
 687
 688         sp->part_number_firmware = version;
 689
 690         version = devm_rave_sp_version(dev, &status.bootloader_version);
 691         if (!version)
 692                 return -ENOMEM;
 693
 694         sp->part_number_bootloader = version;
 695
 696         return 0;
 697 }
 698
 699 static const struct rave_sp_checksum rave_sp_checksum_8b2c = {
 700         .length     = 1,
 701         .subroutine = csum_8b2c,
 702 };
 703
 704 static const struct rave_sp_checksum rave_sp_checksum_ccitt = {
 705         .length     = 2,
 706         .subroutine = csum_ccitt,
 707 };
 708
 709 static const struct rave_sp_variant rave_sp_legacy = {
 710         .checksum = &rave_sp_checksum_8b2c,
 711         .cmd = {
 712                 .translate = rave_sp_default_cmd_translate,
 713         },
 714 };
 715
 716 static const struct rave_sp_variant rave_sp_rdu1 = {
 717         .checksum = &rave_sp_checksum_8b2c,
 718         .cmd = {
 719                 .translate = rave_sp_rdu1_cmd_translate,
 720         },
 721 };
 722
 723 static const struct rave_sp_variant rave_sp_rdu2 = {
 724         .checksum = &rave_sp_checksum_ccitt,
 725         .cmd = {
 726                 .translate = rave_sp_rdu2_cmd_translate,
 727         },
 728 };
 729
 730 static const struct of_device_id rave_sp_dt_ids[] = {
 731         { .compatible = "zii,rave-sp-niu",  .data = &rave_sp_legacy },
 732         { .compatible = "zii,rave-sp-mezz", .data = &rave_sp_legacy },
 733         { .compatible = "zii,rave-sp-esb",  .data = &rave_sp_legacy },
 734         { .compatible = "zii,rave-sp-rdu1", .data = &rave_sp_rdu1   },
 735         { .compatible = "zii,rave-sp-rdu2", .data = &rave_sp_rdu2   },
 736         { /* sentinel */ }
 737 };
 738
 739 static const struct serdev_device_ops rave_sp_serdev_device_ops = {
 740         .receive_buf  = rave_sp_receive_buf,
 741         .write_wakeup = serdev_device_write_wakeup,
 742 };
 743
 744 static int rave_sp_probe(struct serdev_device *serdev)
 745 {
 746         struct device *dev = &serdev->dev;
 747         const char *unknown = "unknown\n";
 748         struct rave_sp *sp;
 749         u32 baud;
 750         int ret;
 751
 752         if (of_property_read_u32(dev->of_node, "current-speed", &baud)) {
 753                 dev_err(dev,
 754                         "'current-speed' is not specified in device node\n");
 755                 return -EINVAL;
 756         }
 757
 758         sp = devm_kzalloc(dev, sizeof(*sp), GFP_KERNEL);
 759         if (!sp)
 760                 return -ENOMEM;
 761
 762         sp->serdev = serdev;
 763         dev_set_drvdata(dev, sp);
 764
 765         sp->variant = of_device_get_match_data(dev);
 766         if (!sp->variant)
 767                 return -ENODEV;
 768
 769         mutex_init(&sp->bus_lock);
 770         mutex_init(&sp->reply_lock);
 771         BLOCKING_INIT_NOTIFIER_HEAD(&sp->event_notifier_list);
 772
 773         serdev_device_set_client_ops(serdev, &rave_sp_serdev_device_ops);
 774         ret = devm_serdev_device_open(dev, serdev);
 775         if (ret)
 776                 return ret;
 777
 778         serdev_device_set_baudrate(serdev, baud);
 779
 780         ret = rave_sp_get_status(sp);
 781         if (ret) {
 782                 dev_warn(dev, "Failed to get firmware status: %d\n", ret);
 783                 sp->part_number_firmware   = unknown;
 784                 sp->part_number_bootloader = unknown;
 785         }
 786
 787         /*
 788          * Those strings already have a \n embedded, so there's no
 789          * need to have one in format string.
 790          */
 791         dev_info(dev, "Firmware version: %s",   sp->part_number_firmware);
 792         dev_info(dev, "Bootloader version: %s", sp->part_number_bootloader);
 793
 794         return devm_of_platform_populate(dev);
 795 }
 796
 797 MODULE_DEVICE_TABLE(of, rave_sp_dt_ids);
 798
 799 static struct serdev_device_driver rave_sp_drv = {
 800         .probe                  = rave_sp_probe,
 801         .driver = {
 802                 .name           = "rave-sp",
 803                 .of_match_table = rave_sp_dt_ids,
 804         },
 805 };
 806 module_serdev_device_driver(rave_sp_drv);
 807
 808 MODULE_LICENSE("GPL");
 809 MODULE_AUTHOR("Andrey Vostrikov <[email protected]>");
 810 MODULE_AUTHOR("Nikita Yushchenko <[email protected]>");
 811 MODULE_AUTHOR("Andrey Smirnov <[email protected]>");
 812 MODULE_DESCRIPTION("RAVE SP core driver");