1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* MHI MBIM Network driver - Network/MBIM over MHI bus 3 * 4 * Copyright (C) 2021 Linaro Ltd <loic.poulain@linaro.org> 5 * 6 * This driver copy some code from cdc_ncm, which is: 7 * Copyright (C) ST-Ericsson 2010-2012 8 * and cdc_mbim, which is: 9 * Copyright (c) 2012 Smith Micro Software, Inc. 10 * Copyright (c) 2012 Bjørn Mork <bjorn@mork.no> 11 * 12 */ 13 14 #include <linux/ethtool.h> 15 #include <linux/if_arp.h> 16 #include <linux/if_vlan.h> 17 #include <linux/ip.h> 18 #include <linux/mhi.h> 19 #include <linux/mii.h> 20 #include <linux/mod_devicetable.h> 21 #include <linux/module.h> 22 #include <linux/netdevice.h> 23 #include <linux/skbuff.h> 24 #include <linux/u64_stats_sync.h> 25 #include <linux/usb.h> 26 #include <linux/usb/cdc.h> 27 #include <linux/usb/usbnet.h> 28 #include <linux/usb/cdc_ncm.h> 29 #include <linux/wwan.h> 30 31 /* 3500 allows to optimize skb allocation, the skbs will basically fit in 32 * one 4K page. Large MBIM packets will simply be split over several MHI 33 * transfers and chained by the MHI net layer (zerocopy). 34 */ 35 #define MHI_DEFAULT_MRU 3500 36 37 #define MHI_MBIM_DEFAULT_MTU 1500 38 #define MHI_MAX_BUF_SZ 0xffff 39 40 #define MBIM_NDP16_SIGN_MASK 0x00ffffff 41 42 #define MHI_MBIM_LINK_HASH_SIZE 8 43 #define LINK_HASH(session) ((session) % MHI_MBIM_LINK_HASH_SIZE) 44 45 struct mhi_mbim_link { 46 struct mhi_mbim_context *mbim; 47 struct net_device *ndev; 48 unsigned int session; 49 50 /* stats */ 51 u64_stats_t rx_packets; 52 u64_stats_t rx_bytes; 53 u64_stats_t rx_errors; 54 u64_stats_t tx_packets; 55 u64_stats_t tx_bytes; 56 u64_stats_t tx_errors; 57 u64_stats_t tx_dropped; 58 struct u64_stats_sync tx_syncp; 59 struct u64_stats_sync rx_syncp; 60 61 struct hlist_node hlnode; 62 }; 63 64 struct mhi_mbim_context { 65 struct mhi_device *mdev; 66 struct sk_buff *skbagg_head; 67 struct sk_buff *skbagg_tail; 68 unsigned int mru; 69 u32 rx_queue_sz; 70 u16 rx_seq; 71 u16 tx_seq; 72 struct delayed_work rx_refill; 73 spinlock_t tx_lock; 74 struct hlist_head link_list[MHI_MBIM_LINK_HASH_SIZE]; 75 }; 76 77 struct mbim_tx_hdr { 78 struct usb_cdc_ncm_nth16 nth16; 79 struct usb_cdc_ncm_ndp16 ndp16; 80 struct usb_cdc_ncm_dpe16 dpe16[2]; 81 } __packed; 82 83 static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim, 84 unsigned int session) 85 { 86 struct mhi_mbim_link *link; 87 88 hlist_for_each_entry_rcu(link, &mbim->link_list[LINK_HASH(session)], hlnode) { 89 if (link->session == session) 90 return link; 91 } 92 93 return NULL; 94 } 95 96 static struct sk_buff *mbim_tx_fixup(struct sk_buff *skb, unsigned int session, 97 u16 tx_seq) 98 { 99 unsigned int dgram_size = skb->len; 100 struct usb_cdc_ncm_nth16 *nth16; 101 struct usb_cdc_ncm_ndp16 *ndp16; 102 struct mbim_tx_hdr *mbim_hdr; 103 104 /* Only one NDP is sent, containing the IP packet (no aggregation) */ 105 106 /* Ensure we have enough headroom for crafting MBIM header */ 107 if (skb_cow_head(skb, sizeof(struct mbim_tx_hdr))) { 108 dev_kfree_skb_any(skb); 109 return NULL; 110 } 111 112 mbim_hdr = skb_push(skb, sizeof(struct mbim_tx_hdr)); 113 114 /* Fill NTB header */ 115 nth16 = &mbim_hdr->nth16; 116 nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN); 117 nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)); 118 nth16->wSequence = cpu_to_le16(tx_seq); 119 nth16->wBlockLength = cpu_to_le16(skb->len); 120 nth16->wNdpIndex = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)); 121 122 /* Fill the unique NDP */ 123 ndp16 = &mbim_hdr->ndp16; 124 ndp16->dwSignature = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN | (session << 24)); 125 ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) 126 + sizeof(struct usb_cdc_ncm_dpe16) * 2); 127 ndp16->wNextNdpIndex = 0; 128 129 /* Datagram follows the mbim header */ 130 ndp16->dpe16[0].wDatagramIndex = cpu_to_le16(sizeof(struct mbim_tx_hdr)); 131 ndp16->dpe16[0].wDatagramLength = cpu_to_le16(dgram_size); 132 133 /* null termination */ 134 ndp16->dpe16[1].wDatagramIndex = 0; 135 ndp16->dpe16[1].wDatagramLength = 0; 136 137 return skb; 138 } 139 140 static netdev_tx_t mhi_mbim_ndo_xmit(struct sk_buff *skb, struct net_device *ndev) 141 { 142 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 143 struct mhi_mbim_context *mbim = link->mbim; 144 unsigned long flags; 145 int err = -ENOMEM; 146 147 /* Serialize MHI channel queuing and MBIM seq */ 148 spin_lock_irqsave(&mbim->tx_lock, flags); 149 150 skb = mbim_tx_fixup(skb, link->session, mbim->tx_seq); 151 if (unlikely(!skb)) 152 goto exit_unlock; 153 154 err = mhi_queue_skb(mbim->mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT); 155 156 if (mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE)) 157 netif_stop_queue(ndev); 158 159 if (!err) 160 mbim->tx_seq++; 161 162 exit_unlock: 163 spin_unlock_irqrestore(&mbim->tx_lock, flags); 164 165 if (unlikely(err)) { 166 net_err_ratelimited("%s: Failed to queue TX buf (%d)\n", 167 ndev->name, err); 168 dev_kfree_skb_any(skb); 169 goto exit_drop; 170 } 171 172 return NETDEV_TX_OK; 173 174 exit_drop: 175 u64_stats_update_begin(&link->tx_syncp); 176 u64_stats_inc(&link->tx_dropped); 177 u64_stats_update_end(&link->tx_syncp); 178 179 return NETDEV_TX_OK; 180 } 181 182 static int mbim_rx_verify_nth16(struct mhi_mbim_context *mbim, struct sk_buff *skb) 183 { 184 struct usb_cdc_ncm_nth16 *nth16; 185 int len; 186 187 if (skb->len < sizeof(struct usb_cdc_ncm_nth16) + 188 sizeof(struct usb_cdc_ncm_ndp16)) { 189 net_err_ratelimited("frame too short\n"); 190 return -EINVAL; 191 } 192 193 nth16 = (struct usb_cdc_ncm_nth16 *)skb->data; 194 195 if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) { 196 net_err_ratelimited("invalid NTH16 signature <%#010x>\n", 197 le32_to_cpu(nth16->dwSignature)); 198 return -EINVAL; 199 } 200 201 /* No limit on the block length, except the size of the data pkt */ 202 len = le16_to_cpu(nth16->wBlockLength); 203 if (len > skb->len) { 204 net_err_ratelimited("NTB does not fit into the skb %u/%u\n", 205 len, skb->len); 206 return -EINVAL; 207 } 208 209 if (mbim->rx_seq + 1 != le16_to_cpu(nth16->wSequence) && 210 (mbim->rx_seq || le16_to_cpu(nth16->wSequence)) && 211 !(mbim->rx_seq == 0xffff && !le16_to_cpu(nth16->wSequence))) { 212 net_err_ratelimited("sequence number glitch prev=%d curr=%d\n", 213 mbim->rx_seq, le16_to_cpu(nth16->wSequence)); 214 } 215 mbim->rx_seq = le16_to_cpu(nth16->wSequence); 216 217 return le16_to_cpu(nth16->wNdpIndex); 218 } 219 220 static int mbim_rx_verify_ndp16(struct sk_buff *skb, struct usb_cdc_ncm_ndp16 *ndp16) 221 { 222 int ret; 223 224 if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) { 225 net_err_ratelimited("invalid DPT16 length <%u>\n", 226 le16_to_cpu(ndp16->wLength)); 227 return -EINVAL; 228 } 229 230 ret = ((le16_to_cpu(ndp16->wLength) - sizeof(struct usb_cdc_ncm_ndp16)) 231 / sizeof(struct usb_cdc_ncm_dpe16)); 232 ret--; /* Last entry is always a NULL terminator */ 233 234 if (sizeof(struct usb_cdc_ncm_ndp16) + 235 ret * sizeof(struct usb_cdc_ncm_dpe16) > skb->len) { 236 net_err_ratelimited("Invalid nframes = %d\n", ret); 237 return -EINVAL; 238 } 239 240 return ret; 241 } 242 243 static void mhi_mbim_rx(struct mhi_mbim_context *mbim, struct sk_buff *skb) 244 { 245 int ndpoffset; 246 247 /* Check NTB header and retrieve first NDP offset */ 248 ndpoffset = mbim_rx_verify_nth16(mbim, skb); 249 if (ndpoffset < 0) { 250 net_err_ratelimited("mbim: Incorrect NTB header\n"); 251 goto error; 252 } 253 254 /* Process each NDP */ 255 while (1) { 256 struct usb_cdc_ncm_ndp16 ndp16; 257 struct usb_cdc_ncm_dpe16 dpe16; 258 struct mhi_mbim_link *link; 259 int nframes, n, dpeoffset; 260 unsigned int session; 261 262 if (skb_copy_bits(skb, ndpoffset, &ndp16, sizeof(ndp16))) { 263 net_err_ratelimited("mbim: Incorrect NDP offset (%u)\n", 264 ndpoffset); 265 goto error; 266 } 267 268 /* Check NDP header and retrieve number of datagrams */ 269 nframes = mbim_rx_verify_ndp16(skb, &ndp16); 270 if (nframes < 0) { 271 net_err_ratelimited("mbim: Incorrect NDP16\n"); 272 goto error; 273 } 274 275 /* Only IP data type supported, no DSS in MHI context */ 276 if ((ndp16.dwSignature & cpu_to_le32(MBIM_NDP16_SIGN_MASK)) 277 != cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN)) { 278 net_err_ratelimited("mbim: Unsupported NDP type\n"); 279 goto next_ndp; 280 } 281 282 session = (le32_to_cpu(ndp16.dwSignature) & ~MBIM_NDP16_SIGN_MASK) >> 24; 283 284 rcu_read_lock(); 285 286 link = mhi_mbim_get_link_rcu(mbim, session); 287 if (!link) { 288 net_err_ratelimited("mbim: bad packet session (%u)\n", session); 289 goto unlock; 290 } 291 292 /* de-aggregate and deliver IP packets */ 293 dpeoffset = ndpoffset + sizeof(struct usb_cdc_ncm_ndp16); 294 for (n = 0; n < nframes; n++, dpeoffset += sizeof(dpe16)) { 295 u16 dgram_offset, dgram_len; 296 struct sk_buff *skbn; 297 298 if (skb_copy_bits(skb, dpeoffset, &dpe16, sizeof(dpe16))) 299 break; 300 301 dgram_offset = le16_to_cpu(dpe16.wDatagramIndex); 302 dgram_len = le16_to_cpu(dpe16.wDatagramLength); 303 304 if (!dgram_offset || !dgram_len) 305 break; /* null terminator */ 306 307 skbn = netdev_alloc_skb(link->ndev, dgram_len); 308 if (!skbn) 309 continue; 310 311 skb_put(skbn, dgram_len); 312 skb_copy_bits(skb, dgram_offset, skbn->data, dgram_len); 313 314 switch (skbn->data[0] & 0xf0) { 315 case 0x40: 316 skbn->protocol = htons(ETH_P_IP); 317 break; 318 case 0x60: 319 skbn->protocol = htons(ETH_P_IPV6); 320 break; 321 default: 322 net_err_ratelimited("%s: unknown protocol\n", 323 link->ndev->name); 324 dev_kfree_skb_any(skbn); 325 u64_stats_update_begin(&link->rx_syncp); 326 u64_stats_inc(&link->rx_errors); 327 u64_stats_update_end(&link->rx_syncp); 328 continue; 329 } 330 331 u64_stats_update_begin(&link->rx_syncp); 332 u64_stats_inc(&link->rx_packets); 333 u64_stats_add(&link->rx_bytes, skbn->len); 334 u64_stats_update_end(&link->rx_syncp); 335 336 netif_rx(skbn); 337 } 338 unlock: 339 rcu_read_unlock(); 340 next_ndp: 341 /* Other NDP to process? */ 342 ndpoffset = (int)le16_to_cpu(ndp16.wNextNdpIndex); 343 if (!ndpoffset) 344 break; 345 } 346 347 /* free skb */ 348 dev_consume_skb_any(skb); 349 return; 350 error: 351 dev_kfree_skb_any(skb); 352 } 353 354 static struct sk_buff *mhi_net_skb_agg(struct mhi_mbim_context *mbim, 355 struct sk_buff *skb) 356 { 357 struct sk_buff *head = mbim->skbagg_head; 358 struct sk_buff *tail = mbim->skbagg_tail; 359 360 /* This is non-paged skb chaining using frag_list */ 361 if (!head) { 362 mbim->skbagg_head = skb; 363 return skb; 364 } 365 366 if (!skb_shinfo(head)->frag_list) 367 skb_shinfo(head)->frag_list = skb; 368 else 369 tail->next = skb; 370 371 head->len += skb->len; 372 head->data_len += skb->len; 373 head->truesize += skb->truesize; 374 375 mbim->skbagg_tail = skb; 376 377 return mbim->skbagg_head; 378 } 379 380 static void mhi_net_rx_refill_work(struct work_struct *work) 381 { 382 struct mhi_mbim_context *mbim = container_of(work, struct mhi_mbim_context, 383 rx_refill.work); 384 struct mhi_device *mdev = mbim->mdev; 385 int err; 386 387 while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) { 388 struct sk_buff *skb = alloc_skb(MHI_DEFAULT_MRU, GFP_KERNEL); 389 390 if (unlikely(!skb)) 391 break; 392 393 err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb, 394 MHI_DEFAULT_MRU, MHI_EOT); 395 if (unlikely(err)) { 396 kfree_skb(skb); 397 break; 398 } 399 400 /* Do not hog the CPU if rx buffers are consumed faster than 401 * queued (unlikely). 402 */ 403 cond_resched(); 404 } 405 406 /* If we're still starved of rx buffers, reschedule later */ 407 if (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mbim->rx_queue_sz) 408 schedule_delayed_work(&mbim->rx_refill, HZ / 2); 409 } 410 411 static void mhi_mbim_dl_callback(struct mhi_device *mhi_dev, 412 struct mhi_result *mhi_res) 413 { 414 struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev); 415 struct sk_buff *skb = mhi_res->buf_addr; 416 int free_desc_count; 417 418 free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE); 419 420 if (unlikely(mhi_res->transaction_status)) { 421 switch (mhi_res->transaction_status) { 422 case -EOVERFLOW: 423 /* Packet has been split over multiple transfers */ 424 skb_put(skb, mhi_res->bytes_xferd); 425 mhi_net_skb_agg(mbim, skb); 426 break; 427 case -ENOTCONN: 428 /* MHI layer stopping/resetting the DL channel */ 429 dev_kfree_skb_any(skb); 430 return; 431 default: 432 /* Unknown error, simply drop */ 433 dev_kfree_skb_any(skb); 434 } 435 } else { 436 skb_put(skb, mhi_res->bytes_xferd); 437 438 if (mbim->skbagg_head) { 439 /* Aggregate the final fragment */ 440 skb = mhi_net_skb_agg(mbim, skb); 441 mbim->skbagg_head = NULL; 442 } 443 444 mhi_mbim_rx(mbim, skb); 445 } 446 447 /* Refill if RX buffers queue becomes low */ 448 if (free_desc_count >= mbim->rx_queue_sz / 2) 449 schedule_delayed_work(&mbim->rx_refill, 0); 450 } 451 452 static void mhi_mbim_ndo_get_stats64(struct net_device *ndev, 453 struct rtnl_link_stats64 *stats) 454 { 455 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 456 unsigned int start; 457 458 do { 459 start = u64_stats_fetch_begin_irq(&link->rx_syncp); 460 stats->rx_packets = u64_stats_read(&link->rx_packets); 461 stats->rx_bytes = u64_stats_read(&link->rx_bytes); 462 stats->rx_errors = u64_stats_read(&link->rx_errors); 463 } while (u64_stats_fetch_retry_irq(&link->rx_syncp, start)); 464 465 do { 466 start = u64_stats_fetch_begin_irq(&link->tx_syncp); 467 stats->tx_packets = u64_stats_read(&link->tx_packets); 468 stats->tx_bytes = u64_stats_read(&link->tx_bytes); 469 stats->tx_errors = u64_stats_read(&link->tx_errors); 470 stats->tx_dropped = u64_stats_read(&link->tx_dropped); 471 } while (u64_stats_fetch_retry_irq(&link->tx_syncp, start)); 472 } 473 474 static void mhi_mbim_ul_callback(struct mhi_device *mhi_dev, 475 struct mhi_result *mhi_res) 476 { 477 struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev); 478 struct sk_buff *skb = mhi_res->buf_addr; 479 struct net_device *ndev = skb->dev; 480 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 481 482 /* Hardware has consumed the buffer, so free the skb (which is not 483 * freed by the MHI stack) and perform accounting. 484 */ 485 dev_consume_skb_any(skb); 486 487 u64_stats_update_begin(&link->tx_syncp); 488 if (unlikely(mhi_res->transaction_status)) { 489 /* MHI layer stopping/resetting the UL channel */ 490 if (mhi_res->transaction_status == -ENOTCONN) { 491 u64_stats_update_end(&link->tx_syncp); 492 return; 493 } 494 495 u64_stats_inc(&link->tx_errors); 496 } else { 497 u64_stats_inc(&link->tx_packets); 498 u64_stats_add(&link->tx_bytes, mhi_res->bytes_xferd); 499 } 500 u64_stats_update_end(&link->tx_syncp); 501 502 if (netif_queue_stopped(ndev) && !mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE)) 503 netif_wake_queue(ndev); 504 } 505 506 static int mhi_mbim_ndo_open(struct net_device *ndev) 507 { 508 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 509 510 /* Feed the MHI rx buffer pool */ 511 schedule_delayed_work(&link->mbim->rx_refill, 0); 512 513 /* Carrier is established via out-of-band channel (e.g. qmi) */ 514 netif_carrier_on(ndev); 515 516 netif_start_queue(ndev); 517 518 return 0; 519 } 520 521 static int mhi_mbim_ndo_stop(struct net_device *ndev) 522 { 523 netif_stop_queue(ndev); 524 netif_carrier_off(ndev); 525 526 return 0; 527 } 528 529 static const struct net_device_ops mhi_mbim_ndo = { 530 .ndo_open = mhi_mbim_ndo_open, 531 .ndo_stop = mhi_mbim_ndo_stop, 532 .ndo_start_xmit = mhi_mbim_ndo_xmit, 533 .ndo_get_stats64 = mhi_mbim_ndo_get_stats64, 534 }; 535 536 static int mhi_mbim_newlink(void *ctxt, struct net_device *ndev, u32 if_id, 537 struct netlink_ext_ack *extack) 538 { 539 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 540 struct mhi_mbim_context *mbim = ctxt; 541 542 link->session = if_id; 543 link->mbim = mbim; 544 link->ndev = ndev; 545 u64_stats_init(&link->rx_syncp); 546 u64_stats_init(&link->tx_syncp); 547 548 rcu_read_lock(); 549 if (mhi_mbim_get_link_rcu(mbim, if_id)) { 550 rcu_read_unlock(); 551 return -EEXIST; 552 } 553 rcu_read_unlock(); 554 555 /* Already protected by RTNL lock */ 556 hlist_add_head_rcu(&link->hlnode, &mbim->link_list[LINK_HASH(if_id)]); 557 558 return register_netdevice(ndev); 559 } 560 561 static void mhi_mbim_dellink(void *ctxt, struct net_device *ndev, 562 struct list_head *head) 563 { 564 struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev); 565 566 hlist_del_init_rcu(&link->hlnode); 567 synchronize_rcu(); 568 569 unregister_netdevice_queue(ndev, head); 570 } 571 572 static void mhi_mbim_setup(struct net_device *ndev) 573 { 574 ndev->header_ops = NULL; /* No header */ 575 ndev->type = ARPHRD_RAWIP; 576 ndev->needed_headroom = sizeof(struct mbim_tx_hdr); 577 ndev->hard_header_len = 0; 578 ndev->addr_len = 0; 579 ndev->flags = IFF_POINTOPOINT | IFF_NOARP; 580 ndev->netdev_ops = &mhi_mbim_ndo; 581 ndev->mtu = MHI_MBIM_DEFAULT_MTU; 582 ndev->min_mtu = ETH_MIN_MTU; 583 ndev->max_mtu = MHI_MAX_BUF_SZ - ndev->needed_headroom; 584 ndev->tx_queue_len = 1000; 585 } 586 587 static const struct wwan_ops mhi_mbim_wwan_ops = { 588 .priv_size = sizeof(struct mhi_mbim_link), 589 .setup = mhi_mbim_setup, 590 .newlink = mhi_mbim_newlink, 591 .dellink = mhi_mbim_dellink, 592 }; 593 594 static int mhi_mbim_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id) 595 { 596 struct mhi_controller *cntrl = mhi_dev->mhi_cntrl; 597 struct mhi_mbim_context *mbim; 598 int err; 599 600 mbim = devm_kzalloc(&mhi_dev->dev, sizeof(*mbim), GFP_KERNEL); 601 if (!mbim) 602 return -ENOMEM; 603 604 spin_lock_init(&mbim->tx_lock); 605 dev_set_drvdata(&mhi_dev->dev, mbim); 606 mbim->mdev = mhi_dev; 607 mbim->mru = mhi_dev->mhi_cntrl->mru ? mhi_dev->mhi_cntrl->mru : MHI_DEFAULT_MRU; 608 609 INIT_DELAYED_WORK(&mbim->rx_refill, mhi_net_rx_refill_work); 610 611 /* Start MHI channels */ 612 err = mhi_prepare_for_transfer(mhi_dev); 613 if (err) 614 return err; 615 616 /* Number of transfer descriptors determines size of the queue */ 617 mbim->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE); 618 619 /* Register wwan link ops with MHI controller representing WWAN instance */ 620 return wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_mbim_wwan_ops, mbim, 0); 621 } 622 623 static void mhi_mbim_remove(struct mhi_device *mhi_dev) 624 { 625 struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev); 626 struct mhi_controller *cntrl = mhi_dev->mhi_cntrl; 627 628 mhi_unprepare_from_transfer(mhi_dev); 629 cancel_delayed_work_sync(&mbim->rx_refill); 630 wwan_unregister_ops(&cntrl->mhi_dev->dev); 631 kfree_skb(mbim->skbagg_head); 632 dev_set_drvdata(&mhi_dev->dev, NULL); 633 } 634 635 static const struct mhi_device_id mhi_mbim_id_table[] = { 636 /* Hardware accelerated data PATH (to modem IPA), MBIM protocol */ 637 { .chan = "IP_HW0_MBIM", .driver_data = 0 }, 638 {} 639 }; 640 MODULE_DEVICE_TABLE(mhi, mhi_mbim_id_table); 641 642 static struct mhi_driver mhi_mbim_driver = { 643 .probe = mhi_mbim_probe, 644 .remove = mhi_mbim_remove, 645 .dl_xfer_cb = mhi_mbim_dl_callback, 646 .ul_xfer_cb = mhi_mbim_ul_callback, 647 .id_table = mhi_mbim_id_table, 648 .driver = { 649 .name = "mhi_wwan_mbim", 650 .owner = THIS_MODULE, 651 }, 652 }; 653 654 module_mhi_driver(mhi_mbim_driver); 655 656 MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>"); 657 MODULE_DESCRIPTION("Network/MBIM over MHI"); 658 MODULE_LICENSE("GPL v2"); 659