1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implements DMTF specification 4 * "DSP0233 Management Component Transport Protocol (MCTP) I3C Transport 5 * Binding" 6 * https://www.dmtf.org/sites/default/files/standards/documents/DSP0233_1.0.0.pdf 7 * 8 * Copyright (c) 2023 Code Construct 9 */ 10 11 #include <linux/module.h> 12 #include <linux/netdevice.h> 13 #include <linux/i3c/device.h> 14 #include <linux/i3c/master.h> 15 #include <linux/if_arp.h> 16 #include <linux/unaligned.h> 17 #include <net/mctp.h> 18 #include <net/mctpdevice.h> 19 20 #define MCTP_I3C_MAXBUF 65536 21 /* 48 bit Provisioned Id */ 22 #define PID_SIZE 6 23 24 /* 64 byte payload, 4 byte MCTP header */ 25 static const int MCTP_I3C_MINMTU = 64 + 4; 26 /* One byte less to allow for the PEC */ 27 static const int MCTP_I3C_MAXMTU = MCTP_I3C_MAXBUF - 1; 28 /* 4 byte MCTP header, no data, 1 byte PEC */ 29 static const int MCTP_I3C_MINLEN = 4 + 1; 30 31 /* Sufficient for 64kB at min mtu */ 32 static const int MCTP_I3C_TX_QUEUE_LEN = 1100; 33 34 /* Somewhat arbitrary */ 35 static const int MCTP_I3C_IBI_SLOTS = 8; 36 37 /* Mandatory Data Byte in an IBI, from DSP0233 */ 38 #define I3C_MDB_MCTP 0xAE 39 /* From MIPI Device Characteristics Register (DCR) Assignments */ 40 #define I3C_DCR_MCTP 0xCC 41 42 static const char *MCTP_I3C_OF_PROP = "mctp-controller"; 43 44 /* List of mctp_i3c_busdev */ 45 static LIST_HEAD(busdevs); 46 /* Protects busdevs, as well as mctp_i3c_bus.devs lists */ 47 static DEFINE_MUTEX(busdevs_lock); 48 49 struct mctp_i3c_bus { 50 struct net_device *ndev; 51 52 struct task_struct *tx_thread; 53 wait_queue_head_t tx_wq; 54 /* tx_lock protects tx_skb and devs */ 55 spinlock_t tx_lock; 56 /* Next skb to transmit */ 57 struct sk_buff *tx_skb; 58 /* Scratch buffer for xmit */ 59 u8 tx_scratch[MCTP_I3C_MAXBUF]; 60 61 /* Element of busdevs */ 62 struct list_head list; 63 64 /* Provisioned ID of our controller */ 65 u64 pid; 66 67 struct i3c_bus *bus; 68 /* Head of mctp_i3c_device.list. Protected by busdevs_lock */ 69 struct list_head devs; 70 }; 71 72 struct mctp_i3c_device { 73 struct i3c_device *i3c; 74 struct mctp_i3c_bus *mbus; 75 struct list_head list; /* Element of mctp_i3c_bus.devs */ 76 77 /* Held while tx_thread is using this device */ 78 struct mutex lock; 79 80 /* Whether BCR indicates MDB is present in IBI */ 81 bool have_mdb; 82 /* I3C dynamic address */ 83 u8 addr; 84 /* Maximum read length */ 85 u16 mrl; 86 /* Maximum write length */ 87 u16 mwl; 88 /* Provisioned ID */ 89 u64 pid; 90 }; 91 92 /* We synthesise a mac header using the Provisioned ID. 93 * Used to pass dest to mctp_i3c_start_xmit. 94 */ 95 struct mctp_i3c_internal_hdr { 96 u8 dest[PID_SIZE]; 97 u8 source[PID_SIZE]; 98 } __packed; 99 100 static int mctp_i3c_read(struct mctp_i3c_device *mi) 101 { 102 struct i3c_priv_xfer xfer = { .rnw = 1, .len = mi->mrl }; 103 struct net_device_stats *stats = &mi->mbus->ndev->stats; 104 struct mctp_i3c_internal_hdr *ihdr = NULL; 105 struct sk_buff *skb = NULL; 106 struct mctp_skb_cb *cb; 107 int net_status, rc; 108 u8 pec, addr; 109 110 skb = netdev_alloc_skb(mi->mbus->ndev, 111 mi->mrl + sizeof(struct mctp_i3c_internal_hdr)); 112 if (!skb) { 113 stats->rx_dropped++; 114 rc = -ENOMEM; 115 goto err; 116 } 117 118 skb->protocol = htons(ETH_P_MCTP); 119 /* Create a header for internal use */ 120 skb_reset_mac_header(skb); 121 ihdr = skb_put(skb, sizeof(struct mctp_i3c_internal_hdr)); 122 put_unaligned_be48(mi->pid, ihdr->source); 123 put_unaligned_be48(mi->mbus->pid, ihdr->dest); 124 skb_pull(skb, sizeof(struct mctp_i3c_internal_hdr)); 125 126 xfer.data.in = skb_put(skb, mi->mrl); 127 128 rc = i3c_device_do_priv_xfers(mi->i3c, &xfer, 1); 129 if (rc < 0) 130 goto err; 131 132 if (WARN_ON_ONCE(xfer.len > mi->mrl)) { 133 /* Bad i3c bus driver */ 134 rc = -EIO; 135 goto err; 136 } 137 if (xfer.len < MCTP_I3C_MINLEN) { 138 stats->rx_length_errors++; 139 rc = -EIO; 140 goto err; 141 } 142 143 /* check PEC, including address byte */ 144 addr = mi->addr << 1 | 1; 145 pec = i2c_smbus_pec(0, &addr, 1); 146 pec = i2c_smbus_pec(pec, xfer.data.in, xfer.len - 1); 147 if (pec != ((u8 *)xfer.data.in)[xfer.len - 1]) { 148 stats->rx_crc_errors++; 149 rc = -EINVAL; 150 goto err; 151 } 152 153 /* Remove PEC */ 154 skb_trim(skb, xfer.len - 1); 155 156 cb = __mctp_cb(skb); 157 cb->halen = PID_SIZE; 158 put_unaligned_be48(mi->pid, cb->haddr); 159 160 net_status = netif_rx(skb); 161 162 if (net_status == NET_RX_SUCCESS) { 163 stats->rx_packets++; 164 stats->rx_bytes += xfer.len - 1; 165 } else { 166 stats->rx_dropped++; 167 } 168 169 return 0; 170 err: 171 kfree_skb(skb); 172 return rc; 173 } 174 175 static void mctp_i3c_ibi_handler(struct i3c_device *i3c, 176 const struct i3c_ibi_payload *payload) 177 { 178 struct mctp_i3c_device *mi = i3cdev_get_drvdata(i3c); 179 180 if (WARN_ON_ONCE(!mi)) 181 return; 182 183 if (mi->have_mdb) { 184 if (payload->len > 0) { 185 if (((u8 *)payload->data)[0] != I3C_MDB_MCTP) { 186 /* Not a mctp-i3c interrupt, ignore it */ 187 return; 188 } 189 } else { 190 /* The BCR advertised a Mandatory Data Byte but the 191 * device didn't send one. 192 */ 193 dev_warn_once(i3cdev_to_dev(i3c), "IBI with missing MDB"); 194 } 195 } 196 197 mctp_i3c_read(mi); 198 } 199 200 static int mctp_i3c_setup(struct mctp_i3c_device *mi) 201 { 202 const struct i3c_ibi_setup ibi = { 203 .max_payload_len = 1, 204 .num_slots = MCTP_I3C_IBI_SLOTS, 205 .handler = mctp_i3c_ibi_handler, 206 }; 207 struct i3c_device_info info; 208 int rc; 209 210 i3c_device_get_info(mi->i3c, &info); 211 mi->have_mdb = info.bcr & BIT(2); 212 mi->addr = info.dyn_addr; 213 mi->mwl = info.max_write_len; 214 mi->mrl = info.max_read_len; 215 mi->pid = info.pid; 216 217 rc = i3c_device_request_ibi(mi->i3c, &ibi); 218 if (rc == -ENOTSUPP) { 219 /* This driver only supports In-Band Interrupt mode. 220 * Support for Polling Mode could be added if required. 221 * (ENOTSUPP is from the i3c layer, not EOPNOTSUPP). 222 */ 223 dev_warn(i3cdev_to_dev(mi->i3c), 224 "Failed, bus driver doesn't support In-Band Interrupts"); 225 goto err; 226 } else if (rc < 0) { 227 dev_err(i3cdev_to_dev(mi->i3c), 228 "Failed requesting IBI (%d)\n", rc); 229 goto err; 230 } 231 232 rc = i3c_device_enable_ibi(mi->i3c); 233 if (rc < 0) { 234 /* Assume a driver supporting request_ibi also 235 * supports enable_ibi. 236 */ 237 dev_err(i3cdev_to_dev(mi->i3c), "Failed enabling IBI (%d)\n", rc); 238 goto err_free_ibi; 239 } 240 241 return 0; 242 243 err_free_ibi: 244 i3c_device_free_ibi(mi->i3c); 245 246 err: 247 return rc; 248 } 249 250 /* Adds a new MCTP i3c_device to a bus */ 251 static int mctp_i3c_add_device(struct mctp_i3c_bus *mbus, 252 struct i3c_device *i3c) 253 __must_hold(&busdevs_lock) 254 { 255 struct mctp_i3c_device *mi = NULL; 256 int rc; 257 258 mi = kzalloc(sizeof(*mi), GFP_KERNEL); 259 if (!mi) { 260 rc = -ENOMEM; 261 goto err; 262 } 263 mi->mbus = mbus; 264 mi->i3c = i3c; 265 mutex_init(&mi->lock); 266 list_add(&mi->list, &mbus->devs); 267 268 i3cdev_set_drvdata(i3c, mi); 269 rc = mctp_i3c_setup(mi); 270 if (rc < 0) 271 goto err_free; 272 273 return 0; 274 275 err_free: 276 list_del(&mi->list); 277 kfree(mi); 278 279 err: 280 dev_warn(i3cdev_to_dev(i3c), "Error adding mctp-i3c device, %d\n", rc); 281 return rc; 282 } 283 284 static int mctp_i3c_probe(struct i3c_device *i3c) 285 { 286 struct mctp_i3c_bus *b = NULL, *mbus = NULL; 287 288 /* Look for a known bus */ 289 mutex_lock(&busdevs_lock); 290 list_for_each_entry(b, &busdevs, list) 291 if (b->bus == i3c->bus) { 292 mbus = b; 293 break; 294 } 295 mutex_unlock(&busdevs_lock); 296 297 if (!mbus) { 298 /* probably no "mctp-controller" property on the i3c bus */ 299 return -ENODEV; 300 } 301 302 return mctp_i3c_add_device(mbus, i3c); 303 } 304 305 static void mctp_i3c_remove_device(struct mctp_i3c_device *mi) 306 __must_hold(&busdevs_lock) 307 { 308 /* Ensure the tx thread isn't using the device */ 309 mutex_lock(&mi->lock); 310 311 /* Counterpart of mctp_i3c_setup */ 312 i3c_device_disable_ibi(mi->i3c); 313 i3c_device_free_ibi(mi->i3c); 314 315 /* Counterpart of mctp_i3c_add_device */ 316 i3cdev_set_drvdata(mi->i3c, NULL); 317 list_del(&mi->list); 318 319 /* Safe to unlock after removing from the list */ 320 mutex_unlock(&mi->lock); 321 kfree(mi); 322 } 323 324 static void mctp_i3c_remove(struct i3c_device *i3c) 325 { 326 struct mctp_i3c_device *mi = i3cdev_get_drvdata(i3c); 327 328 /* We my have received a Bus Remove notify prior to device remove, 329 * so mi will already be removed. 330 */ 331 if (!mi) 332 return; 333 334 mutex_lock(&busdevs_lock); 335 mctp_i3c_remove_device(mi); 336 mutex_unlock(&busdevs_lock); 337 } 338 339 /* Returns the device for an address, with mi->lock held */ 340 static struct mctp_i3c_device * 341 mctp_i3c_lookup(struct mctp_i3c_bus *mbus, u64 pid) 342 { 343 struct mctp_i3c_device *mi = NULL, *ret = NULL; 344 345 mutex_lock(&busdevs_lock); 346 list_for_each_entry(mi, &mbus->devs, list) 347 if (mi->pid == pid) { 348 ret = mi; 349 mutex_lock(&mi->lock); 350 break; 351 } 352 mutex_unlock(&busdevs_lock); 353 return ret; 354 } 355 356 static void mctp_i3c_xmit(struct mctp_i3c_bus *mbus, struct sk_buff *skb) 357 { 358 struct net_device_stats *stats = &mbus->ndev->stats; 359 struct i3c_priv_xfer xfer = { .rnw = false }; 360 struct mctp_i3c_internal_hdr *ihdr = NULL; 361 struct mctp_i3c_device *mi = NULL; 362 unsigned int data_len; 363 u8 *data = NULL; 364 u8 addr, pec; 365 int rc = 0; 366 u64 pid; 367 368 skb_pull(skb, sizeof(struct mctp_i3c_internal_hdr)); 369 data_len = skb->len; 370 371 ihdr = (void *)skb_mac_header(skb); 372 373 pid = get_unaligned_be48(ihdr->dest); 374 mi = mctp_i3c_lookup(mbus, pid); 375 if (!mi) { 376 /* I3C endpoint went away after the packet was enqueued? */ 377 stats->tx_dropped++; 378 goto out; 379 } 380 381 if (WARN_ON_ONCE(data_len + 1 > MCTP_I3C_MAXBUF)) 382 goto out; 383 384 if (data_len + 1 > (unsigned int)mi->mwl) { 385 /* Route MTU was larger than supported by the endpoint */ 386 stats->tx_dropped++; 387 goto out; 388 } 389 390 /* Need a linear buffer with space for the PEC */ 391 xfer.len = data_len + 1; 392 if (skb_tailroom(skb) >= 1) { 393 skb_put(skb, 1); 394 data = skb->data; 395 } else { 396 /* Otherwise need to copy the buffer */ 397 skb_copy_bits(skb, 0, mbus->tx_scratch, skb->len); 398 data = mbus->tx_scratch; 399 } 400 401 /* PEC calculation */ 402 addr = mi->addr << 1; 403 pec = i2c_smbus_pec(0, &addr, 1); 404 pec = i2c_smbus_pec(pec, data, data_len); 405 data[data_len] = pec; 406 407 xfer.data.out = data; 408 rc = i3c_device_do_priv_xfers(mi->i3c, &xfer, 1); 409 if (rc == 0) { 410 stats->tx_bytes += data_len; 411 stats->tx_packets++; 412 } else { 413 stats->tx_errors++; 414 } 415 416 out: 417 if (mi) 418 mutex_unlock(&mi->lock); 419 } 420 421 static int mctp_i3c_tx_thread(void *data) 422 { 423 struct mctp_i3c_bus *mbus = data; 424 struct sk_buff *skb; 425 426 for (;;) { 427 if (kthread_should_stop()) 428 break; 429 430 spin_lock_bh(&mbus->tx_lock); 431 skb = mbus->tx_skb; 432 mbus->tx_skb = NULL; 433 spin_unlock_bh(&mbus->tx_lock); 434 435 if (netif_queue_stopped(mbus->ndev)) 436 netif_wake_queue(mbus->ndev); 437 438 if (skb) { 439 mctp_i3c_xmit(mbus, skb); 440 kfree_skb(skb); 441 } else { 442 wait_event_idle(mbus->tx_wq, 443 mbus->tx_skb || kthread_should_stop()); 444 } 445 } 446 447 return 0; 448 } 449 450 static netdev_tx_t mctp_i3c_start_xmit(struct sk_buff *skb, 451 struct net_device *ndev) 452 { 453 struct mctp_i3c_bus *mbus = netdev_priv(ndev); 454 netdev_tx_t ret; 455 456 spin_lock(&mbus->tx_lock); 457 netif_stop_queue(ndev); 458 if (mbus->tx_skb) { 459 dev_warn_ratelimited(&ndev->dev, "TX with queue stopped"); 460 ret = NETDEV_TX_BUSY; 461 } else { 462 mbus->tx_skb = skb; 463 ret = NETDEV_TX_OK; 464 } 465 spin_unlock(&mbus->tx_lock); 466 467 if (ret == NETDEV_TX_OK) 468 wake_up(&mbus->tx_wq); 469 470 return ret; 471 } 472 473 static void mctp_i3c_bus_free(struct mctp_i3c_bus *mbus) 474 __must_hold(&busdevs_lock) 475 { 476 struct mctp_i3c_device *mi = NULL, *tmp = NULL; 477 478 if (mbus->tx_thread) { 479 kthread_stop(mbus->tx_thread); 480 mbus->tx_thread = NULL; 481 } 482 483 /* Remove any child devices */ 484 list_for_each_entry_safe(mi, tmp, &mbus->devs, list) { 485 mctp_i3c_remove_device(mi); 486 } 487 488 kfree_skb(mbus->tx_skb); 489 list_del(&mbus->list); 490 } 491 492 static void mctp_i3c_ndo_uninit(struct net_device *ndev) 493 { 494 struct mctp_i3c_bus *mbus = netdev_priv(ndev); 495 496 /* Perform cleanup here to ensure there are no remaining references */ 497 mctp_i3c_bus_free(mbus); 498 } 499 500 static int mctp_i3c_header_create(struct sk_buff *skb, struct net_device *dev, 501 unsigned short type, const void *daddr, 502 const void *saddr, unsigned int len) 503 { 504 struct mctp_i3c_internal_hdr *ihdr; 505 506 skb_push(skb, sizeof(struct mctp_i3c_internal_hdr)); 507 skb_reset_mac_header(skb); 508 ihdr = (void *)skb_mac_header(skb); 509 memcpy(ihdr->dest, daddr, PID_SIZE); 510 memcpy(ihdr->source, saddr, PID_SIZE); 511 return 0; 512 } 513 514 static const struct net_device_ops mctp_i3c_ops = { 515 .ndo_start_xmit = mctp_i3c_start_xmit, 516 .ndo_uninit = mctp_i3c_ndo_uninit, 517 }; 518 519 static const struct header_ops mctp_i3c_headops = { 520 .create = mctp_i3c_header_create, 521 }; 522 523 static void mctp_i3c_net_setup(struct net_device *dev) 524 { 525 dev->type = ARPHRD_MCTP; 526 527 dev->mtu = MCTP_I3C_MAXMTU; 528 dev->min_mtu = MCTP_I3C_MINMTU; 529 dev->max_mtu = MCTP_I3C_MAXMTU; 530 dev->tx_queue_len = MCTP_I3C_TX_QUEUE_LEN; 531 532 dev->hard_header_len = sizeof(struct mctp_i3c_internal_hdr); 533 dev->addr_len = PID_SIZE; 534 535 dev->netdev_ops = &mctp_i3c_ops; 536 dev->header_ops = &mctp_i3c_headops; 537 } 538 539 static bool mctp_i3c_is_mctp_controller(struct i3c_bus *bus) 540 { 541 struct i3c_dev_desc *master = bus->cur_master; 542 543 if (!master) 544 return false; 545 546 return of_property_read_bool(master->common.master->dev.of_node, 547 MCTP_I3C_OF_PROP); 548 } 549 550 /* Returns the Provisioned Id of a local bus master */ 551 static int mctp_i3c_bus_local_pid(struct i3c_bus *bus, u64 *ret_pid) 552 { 553 struct i3c_dev_desc *master; 554 555 master = bus->cur_master; 556 if (WARN_ON_ONCE(!master)) 557 return -ENOENT; 558 *ret_pid = master->info.pid; 559 560 return 0; 561 } 562 563 /* Returns an ERR_PTR on failure */ 564 static struct mctp_i3c_bus *mctp_i3c_bus_add(struct i3c_bus *bus) 565 __must_hold(&busdevs_lock) 566 { 567 struct mctp_i3c_bus *mbus = NULL; 568 struct net_device *ndev = NULL; 569 char namebuf[IFNAMSIZ]; 570 u8 addr[PID_SIZE]; 571 int rc; 572 573 if (!mctp_i3c_is_mctp_controller(bus)) 574 return ERR_PTR(-ENOENT); 575 576 snprintf(namebuf, sizeof(namebuf), "mctpi3c%d", bus->id); 577 ndev = alloc_netdev(sizeof(*mbus), namebuf, NET_NAME_ENUM, 578 mctp_i3c_net_setup); 579 if (!ndev) { 580 rc = -ENOMEM; 581 goto err; 582 } 583 584 mbus = netdev_priv(ndev); 585 mbus->ndev = ndev; 586 mbus->bus = bus; 587 INIT_LIST_HEAD(&mbus->devs); 588 list_add(&mbus->list, &busdevs); 589 590 rc = mctp_i3c_bus_local_pid(bus, &mbus->pid); 591 if (rc < 0) { 592 dev_err(&ndev->dev, "No I3C PID available\n"); 593 goto err_free_uninit; 594 } 595 put_unaligned_be48(mbus->pid, addr); 596 dev_addr_set(ndev, addr); 597 598 init_waitqueue_head(&mbus->tx_wq); 599 spin_lock_init(&mbus->tx_lock); 600 mbus->tx_thread = kthread_run(mctp_i3c_tx_thread, mbus, 601 "%s/tx", ndev->name); 602 if (IS_ERR(mbus->tx_thread)) { 603 dev_warn(&ndev->dev, "Error creating thread: %pe\n", 604 mbus->tx_thread); 605 rc = PTR_ERR(mbus->tx_thread); 606 mbus->tx_thread = NULL; 607 goto err_free_uninit; 608 } 609 610 rc = mctp_register_netdev(ndev, NULL); 611 if (rc < 0) { 612 dev_warn(&ndev->dev, "netdev register failed: %d\n", rc); 613 goto err_free_netdev; 614 } 615 return mbus; 616 617 err_free_uninit: 618 /* uninit will not get called if a netdev has not been registered, 619 * so we perform the same mbus cleanup manually. 620 */ 621 mctp_i3c_bus_free(mbus); 622 623 err_free_netdev: 624 free_netdev(ndev); 625 626 err: 627 return ERR_PTR(rc); 628 } 629 630 static void mctp_i3c_bus_remove(struct mctp_i3c_bus *mbus) 631 __must_hold(&busdevs_lock) 632 { 633 /* Unregister calls through to ndo_uninit -> mctp_i3c_bus_free() */ 634 mctp_unregister_netdev(mbus->ndev); 635 636 free_netdev(mbus->ndev); 637 /* mbus is deallocated */ 638 } 639 640 /* Removes all mctp-i3c busses */ 641 static void mctp_i3c_bus_remove_all(void) 642 { 643 struct mctp_i3c_bus *mbus = NULL, *tmp = NULL; 644 645 mutex_lock(&busdevs_lock); 646 list_for_each_entry_safe(mbus, tmp, &busdevs, list) { 647 mctp_i3c_bus_remove(mbus); 648 } 649 mutex_unlock(&busdevs_lock); 650 } 651 652 /* Adds a i3c_bus if it isn't already in the busdevs list. 653 * Suitable as an i3c_for_each_bus_locked callback. 654 */ 655 static int mctp_i3c_bus_add_new(struct i3c_bus *bus, void *data) 656 { 657 struct mctp_i3c_bus *mbus = NULL, *tmp = NULL; 658 bool exists = false; 659 660 mutex_lock(&busdevs_lock); 661 list_for_each_entry_safe(mbus, tmp, &busdevs, list) 662 if (mbus->bus == bus) 663 exists = true; 664 665 /* It is OK for a bus to already exist. That can occur due to 666 * the race in mod_init between notifier and for_each_bus 667 */ 668 if (!exists) 669 mctp_i3c_bus_add(bus); 670 mutex_unlock(&busdevs_lock); 671 return 0; 672 } 673 674 static void mctp_i3c_notify_bus_remove(struct i3c_bus *bus) 675 { 676 struct mctp_i3c_bus *mbus = NULL, *tmp; 677 678 mutex_lock(&busdevs_lock); 679 list_for_each_entry_safe(mbus, tmp, &busdevs, list) 680 if (mbus->bus == bus) 681 mctp_i3c_bus_remove(mbus); 682 mutex_unlock(&busdevs_lock); 683 } 684 685 static int mctp_i3c_notifier_call(struct notifier_block *nb, 686 unsigned long action, void *data) 687 { 688 switch (action) { 689 case I3C_NOTIFY_BUS_ADD: 690 mctp_i3c_bus_add_new((struct i3c_bus *)data, NULL); 691 break; 692 case I3C_NOTIFY_BUS_REMOVE: 693 mctp_i3c_notify_bus_remove((struct i3c_bus *)data); 694 break; 695 } 696 return NOTIFY_DONE; 697 } 698 699 static struct notifier_block mctp_i3c_notifier = { 700 .notifier_call = mctp_i3c_notifier_call, 701 }; 702 703 static const struct i3c_device_id mctp_i3c_ids[] = { 704 I3C_CLASS(I3C_DCR_MCTP, NULL), 705 { 0 }, 706 }; 707 708 static struct i3c_driver mctp_i3c_driver = { 709 .driver = { 710 .name = "mctp-i3c", 711 }, 712 .probe = mctp_i3c_probe, 713 .remove = mctp_i3c_remove, 714 .id_table = mctp_i3c_ids, 715 }; 716 717 static __init int mctp_i3c_mod_init(void) 718 { 719 int rc; 720 721 rc = i3c_register_notifier(&mctp_i3c_notifier); 722 if (rc < 0) { 723 i3c_driver_unregister(&mctp_i3c_driver); 724 return rc; 725 } 726 727 i3c_for_each_bus_locked(mctp_i3c_bus_add_new, NULL); 728 729 rc = i3c_driver_register(&mctp_i3c_driver); 730 if (rc < 0) 731 return rc; 732 733 return 0; 734 } 735 736 static __exit void mctp_i3c_mod_exit(void) 737 { 738 int rc; 739 740 i3c_driver_unregister(&mctp_i3c_driver); 741 742 rc = i3c_unregister_notifier(&mctp_i3c_notifier); 743 if (rc < 0) 744 pr_warn("MCTP I3C could not unregister notifier, %d\n", rc); 745 746 mctp_i3c_bus_remove_all(); 747 } 748 749 module_init(mctp_i3c_mod_init); 750 module_exit(mctp_i3c_mod_exit); 751 752 MODULE_DEVICE_TABLE(i3c, mctp_i3c_ids); 753 MODULE_DESCRIPTION("MCTP I3C device"); 754 MODULE_LICENSE("GPL"); 755 MODULE_AUTHOR("Matt Johnston <matt@codeconstruct.com.au>"); 756