drivers/net/can/usb/gs_usb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* CAN driver for Geschwister Schneider USB/CAN devices
   3  * and bytewerk.org candleLight USB CAN interfaces.
   4  *
   5  * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
   6  * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
   7  * Copyright (C) 2016 Hubert Denkmair
   8  * Copyright (c) 2023 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
   9  *
  10  * Many thanks to all socketcan devs!
  11  */
  12
  13 #include <linux/bitfield.h>
  14 #include <linux/clocksource.h>
  15 #include <linux/ethtool.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/signal.h>
  20 #include <linux/timecounter.h>
  21 #include <linux/units.h>
  22 #include <linux/usb.h>
  23 #include <linux/workqueue.h>
  24
  25 #include <linux/can.h>
  26 #include <linux/can/dev.h>
  27 #include <linux/can/error.h>
  28 #include <linux/can/rx-offload.h>
  29
  30 /* Device specific constants */
  31 #define USB_GS_USB_1_VENDOR_ID 0x1d50
  32 #define USB_GS_USB_1_PRODUCT_ID 0x606f
  33
  34 #define USB_CANDLELIGHT_VENDOR_ID 0x1209
  35 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
  36
  37 #define USB_CES_CANEXT_FD_VENDOR_ID 0x1cd2
  38 #define USB_CES_CANEXT_FD_PRODUCT_ID 0x606f
  39
  40 #define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
  41 #define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
  42
  43 #define GS_USB_ENDPOINT_IN 1
  44 #define GS_USB_ENDPOINT_OUT 2
  45
  46 /* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
  47  * for timer overflow (will be after ~71 minutes)
  48  */
  49 #define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
  50 #define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
  51 static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
  52               CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
  53
  54 /* Device specific constants */
  55 enum gs_usb_breq {
  56         GS_USB_BREQ_HOST_FORMAT = 0,
  57         GS_USB_BREQ_BITTIMING,
  58         GS_USB_BREQ_MODE,
  59         GS_USB_BREQ_BERR,
  60         GS_USB_BREQ_BT_CONST,
  61         GS_USB_BREQ_DEVICE_CONFIG,
  62         GS_USB_BREQ_TIMESTAMP,
  63         GS_USB_BREQ_IDENTIFY,
  64         GS_USB_BREQ_GET_USER_ID,
  65         GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
  66         GS_USB_BREQ_SET_USER_ID,
  67         GS_USB_BREQ_DATA_BITTIMING,
  68         GS_USB_BREQ_BT_CONST_EXT,
  69         GS_USB_BREQ_SET_TERMINATION,
  70         GS_USB_BREQ_GET_TERMINATION,
  71         GS_USB_BREQ_GET_STATE,
  72 };
  73
  74 enum gs_can_mode {
  75         /* reset a channel. turns it off */
  76         GS_CAN_MODE_RESET = 0,
  77         /* starts a channel */
  78         GS_CAN_MODE_START
  79 };
  80
  81 enum gs_can_state {
  82         GS_CAN_STATE_ERROR_ACTIVE = 0,
  83         GS_CAN_STATE_ERROR_WARNING,
  84         GS_CAN_STATE_ERROR_PASSIVE,
  85         GS_CAN_STATE_BUS_OFF,
  86         GS_CAN_STATE_STOPPED,
  87         GS_CAN_STATE_SLEEPING
  88 };
  89
  90 enum gs_can_identify_mode {
  91         GS_CAN_IDENTIFY_OFF = 0,
  92         GS_CAN_IDENTIFY_ON
  93 };
  94
  95 enum gs_can_termination_state {
  96         GS_CAN_TERMINATION_STATE_OFF = 0,
  97         GS_CAN_TERMINATION_STATE_ON
  98 };
  99
 100 #define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
 101 #define GS_USB_TERMINATION_ENABLED 120
 102
 103 /* data types passed between host and device */
 104
 105 /* The firmware on the original USB2CAN by Geschwister Schneider
 106  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
 107  * between the host and the device in host byte order. This is done
 108  * with the struct gs_host_config::byte_order member, which is sent
 109  * first to indicate the desired byte order.
 110  *
 111  * The widely used open source firmware candleLight doesn't support
 112  * this feature and exchanges the data in little endian byte order.
 113  */
 114 struct gs_host_config {
 115         __le32 byte_order;
 116 } __packed;
 117
 118 struct gs_device_config {
 119         u8 reserved1;
 120         u8 reserved2;
 121         u8 reserved3;
 122         u8 icount;
 123         __le32 sw_version;
 124         __le32 hw_version;
 125 } __packed;
 126
 127 #define GS_CAN_MODE_NORMAL 0
 128 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
 129 #define GS_CAN_MODE_LOOP_BACK BIT(1)
 130 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
 131 #define GS_CAN_MODE_ONE_SHOT BIT(3)
 132 #define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
 133 /* GS_CAN_FEATURE_IDENTIFY BIT(5) */
 134 /* GS_CAN_FEATURE_USER_ID BIT(6) */
 135 #define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
 136 #define GS_CAN_MODE_FD BIT(8)
 137 /* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
 138 /* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
 139 /* GS_CAN_FEATURE_TERMINATION BIT(11) */
 140 #define GS_CAN_MODE_BERR_REPORTING BIT(12)
 141 /* GS_CAN_FEATURE_GET_STATE BIT(13) */
 142
 143 struct gs_device_mode {
 144         __le32 mode;
 145         __le32 flags;
 146 } __packed;
 147
 148 struct gs_device_state {
 149         __le32 state;
 150         __le32 rxerr;
 151         __le32 txerr;
 152 } __packed;
 153
 154 struct gs_device_bittiming {
 155         __le32 prop_seg;
 156         __le32 phase_seg1;
 157         __le32 phase_seg2;
 158         __le32 sjw;
 159         __le32 brp;
 160 } __packed;
 161
 162 struct gs_identify_mode {
 163         __le32 mode;
 164 } __packed;
 165
 166 struct gs_device_termination_state {
 167         __le32 state;
 168 } __packed;
 169
 170 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
 171 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
 172 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
 173 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
 174 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
 175 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
 176 #define GS_CAN_FEATURE_USER_ID BIT(6)
 177 #define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
 178 #define GS_CAN_FEATURE_FD BIT(8)
 179 #define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
 180 #define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
 181 #define GS_CAN_FEATURE_TERMINATION BIT(11)
 182 #define GS_CAN_FEATURE_BERR_REPORTING BIT(12)
 183 #define GS_CAN_FEATURE_GET_STATE BIT(13)
 184 #define GS_CAN_FEATURE_MASK GENMASK(13, 0)
 185
 186 /* internal quirks - keep in GS_CAN_FEATURE space for now */
 187
 188 /* CANtact Pro original firmware:
 189  * BREQ DATA_BITTIMING overlaps with GET_USER_ID
 190  */
 191 #define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
 192
 193 struct gs_device_bt_const {
 194         __le32 feature;
 195         __le32 fclk_can;
 196         __le32 tseg1_min;
 197         __le32 tseg1_max;
 198         __le32 tseg2_min;
 199         __le32 tseg2_max;
 200         __le32 sjw_max;
 201         __le32 brp_min;
 202         __le32 brp_max;
 203         __le32 brp_inc;
 204 } __packed;
 205
 206 struct gs_device_bt_const_extended {
 207         __le32 feature;
 208         __le32 fclk_can;
 209         __le32 tseg1_min;
 210         __le32 tseg1_max;
 211         __le32 tseg2_min;
 212         __le32 tseg2_max;
 213         __le32 sjw_max;
 214         __le32 brp_min;
 215         __le32 brp_max;
 216         __le32 brp_inc;
 217
 218         __le32 dtseg1_min;
 219         __le32 dtseg1_max;
 220         __le32 dtseg2_min;
 221         __le32 dtseg2_max;
 222         __le32 dsjw_max;
 223         __le32 dbrp_min;
 224         __le32 dbrp_max;
 225         __le32 dbrp_inc;
 226 } __packed;
 227
 228 #define GS_CAN_FLAG_OVERFLOW BIT(0)
 229 #define GS_CAN_FLAG_FD BIT(1)
 230 #define GS_CAN_FLAG_BRS BIT(2)
 231 #define GS_CAN_FLAG_ESI BIT(3)
 232
 233 struct classic_can {
 234         u8 data[8];
 235 } __packed;
 236
 237 struct classic_can_ts {
 238         u8 data[8];
 239         __le32 timestamp_us;
 240 } __packed;
 241
 242 struct classic_can_quirk {
 243         u8 data[8];
 244         u8 quirk;
 245 } __packed;
 246
 247 struct canfd {
 248         u8 data[64];
 249 } __packed;
 250
 251 struct canfd_ts {
 252         u8 data[64];
 253         __le32 timestamp_us;
 254 } __packed;
 255
 256 struct canfd_quirk {
 257         u8 data[64];
 258         u8 quirk;
 259 } __packed;
 260
 261 struct gs_host_frame {
 262         u32 echo_id;
 263         __le32 can_id;
 264
 265         u8 can_dlc;
 266         u8 channel;
 267         u8 flags;
 268         u8 reserved;
 269
 270         union {
 271                 DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
 272                 DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
 273                 DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
 274                 DECLARE_FLEX_ARRAY(struct canfd, canfd);
 275                 DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
 276                 DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
 277         };
 278 } __packed;
 279 /* The GS USB devices make use of the same flags and masks as in
 280  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 281  */
 282
 283 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 284 #define GS_MAX_TX_URBS 10
 285 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 286 #define GS_MAX_RX_URBS 30
 287 #define GS_NAPI_WEIGHT 32
 288
 289 /* Maximum number of interfaces the driver supports per device.
 290  * Current hardware only supports 3 interfaces. The future may vary.
 291  */
 292 #define GS_MAX_INTF 3
 293
 294 struct gs_tx_context {
 295         struct gs_can *dev;
 296         unsigned int echo_id;
 297 };
 298
 299 struct gs_can {
 300         struct can_priv can; /* must be the first member */
 301
 302         struct can_rx_offload offload;
 303         struct gs_usb *parent;
 304
 305         struct net_device *netdev;
 306         struct usb_device *udev;
 307
 308         struct can_bittiming_const bt_const, data_bt_const;
 309         unsigned int channel;   /* channel number */
 310
 311         u32 feature;
 312         unsigned int hf_size_tx;
 313
 314         /* This lock prevents a race condition between xmit and receive. */
 315         spinlock_t tx_ctx_lock;
 316         struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 317
 318         struct usb_anchor tx_submitted;
 319         atomic_t active_tx_urbs;
 320 };
 321
 322 /* usb interface struct */
 323 struct gs_usb {
 324         struct gs_can *canch[GS_MAX_INTF];
 325         struct usb_anchor rx_submitted;
 326         struct usb_device *udev;
 327
 328         /* time counter for hardware timestamps */
 329         struct cyclecounter cc;
 330         struct timecounter tc;
 331         spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
 332         struct delayed_work timestamp;
 333
 334         unsigned int hf_size_rx;
 335         u8 active_channels;
 336 };
 337
 338 /* 'allocate' a tx context.
 339  * returns a valid tx context or NULL if there is no space.
 340  */
 341 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 342 {
 343         int i = 0;
 344         unsigned long flags;
 345
 346         spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 347
 348         for (; i < GS_MAX_TX_URBS; i++) {
 349                 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 350                         dev->tx_context[i].echo_id = i;
 351                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 352                         return &dev->tx_context[i];
 353                 }
 354         }
 355
 356         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 357         return NULL;
 358 }
 359
 360 /* releases a tx context
 361  */
 362 static void gs_free_tx_context(struct gs_tx_context *txc)
 363 {
 364         txc->echo_id = GS_MAX_TX_URBS;
 365 }
 366
 367 /* Get a tx context by id.
 368  */
 369 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
 370                                                unsigned int id)
 371 {
 372         unsigned long flags;
 373
 374         if (id < GS_MAX_TX_URBS) {
 375                 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 376                 if (dev->tx_context[id].echo_id == id) {
 377                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 378                         return &dev->tx_context[id];
 379                 }
 380                 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 381         }
 382         return NULL;
 383 }
 384
 385 static int gs_cmd_reset(struct gs_can *dev)
 386 {
 387         struct gs_device_mode dm = {
 388                 .mode = GS_CAN_MODE_RESET,
 389         };
 390
 391         return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
 392                                     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 393                                     dev->channel, 0, &dm, sizeof(dm), 1000,
 394                                     GFP_KERNEL);
 395 }
 396
 397 static inline int gs_usb_get_timestamp(const struct gs_usb *parent,
 398                                        u32 *timestamp_p)
 399 {
 400         __le32 timestamp;
 401         int rc;
 402
 403         rc = usb_control_msg_recv(parent->udev, 0, GS_USB_BREQ_TIMESTAMP,
 404                                   USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 405                                   0, 0,
 406                                   &timestamp, sizeof(timestamp),
 407                                   USB_CTRL_GET_TIMEOUT,
 408                                   GFP_KERNEL);
 409         if (rc)
 410                 return rc;
 411
 412         *timestamp_p = le32_to_cpu(timestamp);
 413
 414         return 0;
 415 }
 416
 417 static u64 gs_usb_timestamp_read(const struct cyclecounter *cc) __must_hold(&dev->tc_lock)
 418 {
 419         struct gs_usb *parent = container_of(cc, struct gs_usb, cc);
 420         u32 timestamp = 0;
 421         int err;
 422
 423         lockdep_assert_held(&parent->tc_lock);
 424
 425         /* drop lock for synchronous USB transfer */
 426         spin_unlock_bh(&parent->tc_lock);
 427         err = gs_usb_get_timestamp(parent, &timestamp);
 428         spin_lock_bh(&parent->tc_lock);
 429         if (err)
 430                 dev_err(&parent->udev->dev,
 431                         "Error %d while reading timestamp. HW timestamps may be inaccurate.",
 432                         err);
 433
 434         return timestamp;
 435 }
 436
 437 static void gs_usb_timestamp_work(struct work_struct *work)
 438 {
 439         struct delayed_work *delayed_work = to_delayed_work(work);
 440         struct gs_usb *parent;
 441
 442         parent = container_of(delayed_work, struct gs_usb, timestamp);
 443         spin_lock_bh(&parent->tc_lock);
 444         timecounter_read(&parent->tc);
 445         spin_unlock_bh(&parent->tc_lock);
 446
 447         schedule_delayed_work(&parent->timestamp,
 448                               GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
 449 }
 450
 451 static void gs_usb_skb_set_timestamp(struct gs_can *dev,
 452                                      struct sk_buff *skb, u32 timestamp)
 453 {
 454         struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
 455         struct gs_usb *parent = dev->parent;
 456         u64 ns;
 457
 458         spin_lock_bh(&parent->tc_lock);
 459         ns = timecounter_cyc2time(&parent->tc, timestamp);
 460         spin_unlock_bh(&parent->tc_lock);
 461
 462         hwtstamps->hwtstamp = ns_to_ktime(ns);
 463 }
 464
 465 static void gs_usb_timestamp_init(struct gs_usb *parent)
 466 {
 467         struct cyclecounter *cc = &parent->cc;
 468
 469         cc->read = gs_usb_timestamp_read;
 470         cc->mask = CYCLECOUNTER_MASK(32);
 471         cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
 472         cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
 473
 474         spin_lock_init(&parent->tc_lock);
 475         spin_lock_bh(&parent->tc_lock);
 476         timecounter_init(&parent->tc, &parent->cc, ktime_get_real_ns());
 477         spin_unlock_bh(&parent->tc_lock);
 478
 479         INIT_DELAYED_WORK(&parent->timestamp, gs_usb_timestamp_work);
 480         schedule_delayed_work(&parent->timestamp,
 481                               GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
 482 }
 483
 484 static void gs_usb_timestamp_stop(struct gs_usb *parent)
 485 {
 486         cancel_delayed_work_sync(&parent->timestamp);
 487 }
 488
 489 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 490 {
 491         struct can_device_stats *can_stats = &dev->can.can_stats;
 492
 493         if (cf->can_id & CAN_ERR_RESTARTED) {
 494                 dev->can.state = CAN_STATE_ERROR_ACTIVE;
 495                 can_stats->restarts++;
 496         } else if (cf->can_id & CAN_ERR_BUSOFF) {
 497                 dev->can.state = CAN_STATE_BUS_OFF;
 498                 can_stats->bus_off++;
 499         } else if (cf->can_id & CAN_ERR_CRTL) {
 500                 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 501                     (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 502                         dev->can.state = CAN_STATE_ERROR_WARNING;
 503                         can_stats->error_warning++;
 504                 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 505                            (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 506                         dev->can.state = CAN_STATE_ERROR_PASSIVE;
 507                         can_stats->error_passive++;
 508                 } else {
 509                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 510                 }
 511         }
 512 }
 513
 514 static u32 gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
 515                                 const struct gs_host_frame *hf)
 516 {
 517         u32 timestamp;
 518
 519         if (hf->flags & GS_CAN_FLAG_FD)
 520                 timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
 521         else
 522                 timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
 523
 524         if (skb)
 525                 gs_usb_skb_set_timestamp(dev, skb, timestamp);
 526
 527         return timestamp;
 528 }
 529
 530 static void gs_usb_rx_offload(struct gs_can *dev, struct sk_buff *skb,
 531                               const struct gs_host_frame *hf)
 532 {
 533         struct can_rx_offload *offload = &dev->offload;
 534         int rc;
 535
 536         if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
 537                 const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
 538
 539                 rc = can_rx_offload_queue_timestamp(offload, skb, ts);
 540         } else {
 541                 rc = can_rx_offload_queue_tail(offload, skb);
 542         }
 543
 544         if (rc)
 545                 dev->netdev->stats.rx_fifo_errors++;
 546 }
 547
 548 static unsigned int
 549 gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb,
 550                     const struct gs_host_frame *hf)
 551 {
 552         struct can_rx_offload *offload = &dev->offload;
 553         const u32 echo_id = hf->echo_id;
 554         unsigned int len;
 555
 556         if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
 557                 const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
 558
 559                 len = can_rx_offload_get_echo_skb_queue_timestamp(offload, echo_id,
 560                                                                   ts, NULL);
 561         } else {
 562                 len = can_rx_offload_get_echo_skb_queue_tail(offload, echo_id,
 563                                                              NULL);
 564         }
 565
 566         return len;
 567 }
 568
 569 static void gs_usb_receive_bulk_callback(struct urb *urb)
 570 {
 571         struct gs_usb *parent = urb->context;
 572         struct gs_can *dev;
 573         struct net_device *netdev;
 574         int rc;
 575         struct net_device_stats *stats;
 576         struct gs_host_frame *hf = urb->transfer_buffer;
 577         struct gs_tx_context *txc;
 578         struct can_frame *cf;
 579         struct canfd_frame *cfd;
 580         struct sk_buff *skb;
 581
 582         BUG_ON(!parent);
 583
 584         switch (urb->status) {
 585         case 0: /* success */
 586                 break;
 587         case -ENOENT:
 588         case -ESHUTDOWN:
 589                 return;
 590         default:
 591                 /* do not resubmit aborted urbs. eg: when device goes down */
 592                 return;
 593         }
 594
 595         /* device reports out of range channel id */
 596         if (hf->channel >= GS_MAX_INTF)
 597                 goto device_detach;
 598
 599         dev = parent->canch[hf->channel];
 600
 601         netdev = dev->netdev;
 602         stats = &netdev->stats;
 603
 604         if (!netif_device_present(netdev))
 605                 return;
 606
 607         if (!netif_running(netdev))
 608                 goto resubmit_urb;
 609
 610         if (hf->echo_id == -1) { /* normal rx */
 611                 if (hf->flags & GS_CAN_FLAG_FD) {
 612                         skb = alloc_canfd_skb(netdev, &cfd);
 613                         if (!skb)
 614                                 return;
 615
 616                         cfd->can_id = le32_to_cpu(hf->can_id);
 617                         cfd->len = can_fd_dlc2len(hf->can_dlc);
 618                         if (hf->flags & GS_CAN_FLAG_BRS)
 619                                 cfd->flags |= CANFD_BRS;
 620                         if (hf->flags & GS_CAN_FLAG_ESI)
 621                                 cfd->flags |= CANFD_ESI;
 622
 623                         memcpy(cfd->data, hf->canfd->data, cfd->len);
 624                 } else {
 625                         skb = alloc_can_skb(netdev, &cf);
 626                         if (!skb)
 627                                 return;
 628
 629                         cf->can_id = le32_to_cpu(hf->can_id);
 630                         can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
 631
 632                         memcpy(cf->data, hf->classic_can->data, 8);
 633
 634                         /* ERROR frames tell us information about the controller */
 635                         if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
 636                                 gs_update_state(dev, cf);
 637                 }
 638
 639                 gs_usb_rx_offload(dev, skb, hf);
 640         } else { /* echo_id == hf->echo_id */
 641                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 642                         netdev_err(netdev,
 643                                    "Unexpected out of range echo id %u\n",
 644                                    hf->echo_id);
 645                         goto resubmit_urb;
 646                 }
 647
 648                 txc = gs_get_tx_context(dev, hf->echo_id);
 649
 650                 /* bad devices send bad echo_ids. */
 651                 if (!txc) {
 652                         netdev_err(netdev,
 653                                    "Unexpected unused echo id %u\n",
 654                                    hf->echo_id);
 655                         goto resubmit_urb;
 656                 }
 657
 658                 skb = dev->can.echo_skb[hf->echo_id];
 659                 stats->tx_packets++;
 660                 stats->tx_bytes += gs_usb_get_echo_skb(dev, skb, hf);
 661                 gs_free_tx_context(txc);
 662
 663                 atomic_dec(&dev->active_tx_urbs);
 664
 665                 netif_wake_queue(netdev);
 666         }
 667
 668         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 669                 stats->rx_over_errors++;
 670                 stats->rx_errors++;
 671
 672                 skb = alloc_can_err_skb(netdev, &cf);
 673                 if (!skb)
 674                         goto resubmit_urb;
 675
 676                 cf->can_id |= CAN_ERR_CRTL;
 677                 cf->len = CAN_ERR_DLC;
 678                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 679
 680                 gs_usb_rx_offload(dev, skb, hf);
 681         }
 682
 683         can_rx_offload_irq_finish(&dev->offload);
 684
 685 resubmit_urb:
 686         usb_fill_bulk_urb(urb, parent->udev,
 687                           usb_rcvbulkpipe(parent->udev, GS_USB_ENDPOINT_IN),
 688                           hf, dev->parent->hf_size_rx,
 689                           gs_usb_receive_bulk_callback, parent);
 690
 691         rc = usb_submit_urb(urb, GFP_ATOMIC);
 692
 693         /* USB failure take down all interfaces */
 694         if (rc == -ENODEV) {
 695 device_detach:
 696                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 697                         if (parent->canch[rc])
 698                                 netif_device_detach(parent->canch[rc]->netdev);
 699                 }
 700         }
 701 }
 702
 703 static int gs_usb_set_bittiming(struct net_device *netdev)
 704 {
 705         struct gs_can *dev = netdev_priv(netdev);
 706         struct can_bittiming *bt = &dev->can.bittiming;
 707         struct gs_device_bittiming dbt = {
 708                 .prop_seg = cpu_to_le32(bt->prop_seg),
 709                 .phase_seg1 = cpu_to_le32(bt->phase_seg1),
 710                 .phase_seg2 = cpu_to_le32(bt->phase_seg2),
 711                 .sjw = cpu_to_le32(bt->sjw),
 712                 .brp = cpu_to_le32(bt->brp),
 713         };
 714
 715         /* request bit timings */
 716         return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_BITTIMING,
 717                                     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 718                                     dev->channel, 0, &dbt, sizeof(dbt), 1000,
 719                                     GFP_KERNEL);
 720 }
 721
 722 static int gs_usb_set_data_bittiming(struct net_device *netdev)
 723 {
 724         struct gs_can *dev = netdev_priv(netdev);
 725         struct can_bittiming *bt = &dev->can.data_bittiming;
 726         struct gs_device_bittiming dbt = {
 727                 .prop_seg = cpu_to_le32(bt->prop_seg),
 728                 .phase_seg1 = cpu_to_le32(bt->phase_seg1),
 729                 .phase_seg2 = cpu_to_le32(bt->phase_seg2),
 730                 .sjw = cpu_to_le32(bt->sjw),
 731                 .brp = cpu_to_le32(bt->brp),
 732         };
 733         u8 request = GS_USB_BREQ_DATA_BITTIMING;
 734
 735         if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
 736                 request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
 737
 738         /* request data bit timings */
 739         return usb_control_msg_send(dev->udev, 0, request,
 740                                     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 741                                     dev->channel, 0, &dbt, sizeof(dbt), 1000,
 742                                     GFP_KERNEL);
 743 }
 744
 745 static void gs_usb_xmit_callback(struct urb *urb)
 746 {
 747         struct gs_tx_context *txc = urb->context;
 748         struct gs_can *dev = txc->dev;
 749         struct net_device *netdev = dev->netdev;
 750
 751         if (urb->status)
 752                 netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
 753 }
 754
 755 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 756                                      struct net_device *netdev)
 757 {
 758         struct gs_can *dev = netdev_priv(netdev);
 759         struct net_device_stats *stats = &dev->netdev->stats;
 760         struct urb *urb;
 761         struct gs_host_frame *hf;
 762         struct can_frame *cf;
 763         struct canfd_frame *cfd;
 764         int rc;
 765         unsigned int idx;
 766         struct gs_tx_context *txc;
 767
 768         if (can_dev_dropped_skb(netdev, skb))
 769                 return NETDEV_TX_OK;
 770
 771         /* find an empty context to keep track of transmission */
 772         txc = gs_alloc_tx_context(dev);
 773         if (!txc)
 774                 return NETDEV_TX_BUSY;
 775
 776         /* create a URB, and a buffer for it */
 777         urb = usb_alloc_urb(0, GFP_ATOMIC);
 778         if (!urb)
 779                 goto nomem_urb;
 780
 781         hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
 782         if (!hf)
 783                 goto nomem_hf;
 784
 785         idx = txc->echo_id;
 786
 787         if (idx >= GS_MAX_TX_URBS) {
 788                 netdev_err(netdev, "Invalid tx context %u\n", idx);
 789                 goto badidx;
 790         }
 791
 792         hf->echo_id = idx;
 793         hf->channel = dev->channel;
 794         hf->flags = 0;
 795         hf->reserved = 0;
 796
 797         if (can_is_canfd_skb(skb)) {
 798                 cfd = (struct canfd_frame *)skb->data;
 799
 800                 hf->can_id = cpu_to_le32(cfd->can_id);
 801                 hf->can_dlc = can_fd_len2dlc(cfd->len);
 802                 hf->flags |= GS_CAN_FLAG_FD;
 803                 if (cfd->flags & CANFD_BRS)
 804                         hf->flags |= GS_CAN_FLAG_BRS;
 805                 if (cfd->flags & CANFD_ESI)
 806                         hf->flags |= GS_CAN_FLAG_ESI;
 807
 808                 memcpy(hf->canfd->data, cfd->data, cfd->len);
 809         } else {
 810                 cf = (struct can_frame *)skb->data;
 811
 812                 hf->can_id = cpu_to_le32(cf->can_id);
 813                 hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
 814
 815                 memcpy(hf->classic_can->data, cf->data, cf->len);
 816         }
 817
 818         usb_fill_bulk_urb(urb, dev->udev,
 819                           usb_sndbulkpipe(dev->udev, GS_USB_ENDPOINT_OUT),
 820                           hf, dev->hf_size_tx,
 821                           gs_usb_xmit_callback, txc);
 822
 823         urb->transfer_flags |= URB_FREE_BUFFER;
 824         usb_anchor_urb(urb, &dev->tx_submitted);
 825
 826         can_put_echo_skb(skb, netdev, idx, 0);
 827
 828         atomic_inc(&dev->active_tx_urbs);
 829
 830         rc = usb_submit_urb(urb, GFP_ATOMIC);
 831         if (unlikely(rc)) {                     /* usb send failed */
 832                 atomic_dec(&dev->active_tx_urbs);
 833
 834                 can_free_echo_skb(netdev, idx, NULL);
 835                 gs_free_tx_context(txc);
 836
 837                 usb_unanchor_urb(urb);
 838
 839                 if (rc == -ENODEV) {
 840                         netif_device_detach(netdev);
 841                 } else {
 842                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 843                         stats->tx_dropped++;
 844                 }
 845         } else {
 846                 /* Slow down tx path */
 847                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 848                         netif_stop_queue(netdev);
 849         }
 850
 851         /* let usb core take care of this urb */
 852         usb_free_urb(urb);
 853
 854         return NETDEV_TX_OK;
 855
 856 badidx:
 857         kfree(hf);
 858 nomem_hf:
 859         usb_free_urb(urb);
 860
 861 nomem_urb:
 862         gs_free_tx_context(txc);
 863         dev_kfree_skb(skb);
 864         stats->tx_dropped++;
 865         return NETDEV_TX_OK;
 866 }
 867
 868 static int gs_can_open(struct net_device *netdev)
 869 {
 870         struct gs_can *dev = netdev_priv(netdev);
 871         struct gs_usb *parent = dev->parent;
 872         struct gs_device_mode dm = {
 873                 .mode = cpu_to_le32(GS_CAN_MODE_START),
 874         };
 875         struct gs_host_frame *hf;
 876         struct urb *urb = NULL;
 877         u32 ctrlmode;
 878         u32 flags = 0;
 879         int rc, i;
 880
 881         rc = open_candev(netdev);
 882         if (rc)
 883                 return rc;
 884
 885         ctrlmode = dev->can.ctrlmode;
 886         if (ctrlmode & CAN_CTRLMODE_FD) {
 887                 if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
 888                         dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
 889                 else
 890                         dev->hf_size_tx = struct_size(hf, canfd, 1);
 891         } else {
 892                 if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
 893                         dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
 894                 else
 895                         dev->hf_size_tx = struct_size(hf, classic_can, 1);
 896         }
 897
 898         can_rx_offload_enable(&dev->offload);
 899
 900         if (!parent->active_channels) {
 901                 if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 902                         gs_usb_timestamp_init(parent);
 903
 904                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 905                         u8 *buf;
 906
 907                         /* alloc rx urb */
 908                         urb = usb_alloc_urb(0, GFP_KERNEL);
 909                         if (!urb) {
 910                                 rc = -ENOMEM;
 911                                 goto out_usb_kill_anchored_urbs;
 912                         }
 913
 914                         /* alloc rx buffer */
 915                         buf = kmalloc(dev->parent->hf_size_rx,
 916                                       GFP_KERNEL);
 917                         if (!buf) {
 918                                 rc = -ENOMEM;
 919                                 goto out_usb_free_urb;
 920                         }
 921
 922                         /* fill, anchor, and submit rx urb */
 923                         usb_fill_bulk_urb(urb,
 924                                           dev->udev,
 925                                           usb_rcvbulkpipe(dev->udev,
 926                                                           GS_USB_ENDPOINT_IN),
 927                                           buf,
 928                                           dev->parent->hf_size_rx,
 929                                           gs_usb_receive_bulk_callback, parent);
 930                         urb->transfer_flags |= URB_FREE_BUFFER;
 931
 932                         usb_anchor_urb(urb, &parent->rx_submitted);
 933
 934                         rc = usb_submit_urb(urb, GFP_KERNEL);
 935                         if (rc) {
 936                                 if (rc == -ENODEV)
 937                                         netif_device_detach(dev->netdev);
 938
 939                                 netdev_err(netdev,
 940                                            "usb_submit_urb() failed, error %pe\n",
 941                                            ERR_PTR(rc));
 942
 943                                 goto out_usb_unanchor_urb;
 944                         }
 945
 946                         /* Drop reference,
 947                          * USB core will take care of freeing it
 948                          */
 949                         usb_free_urb(urb);
 950                 }
 951         }
 952
 953         /* flags */
 954         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 955                 flags |= GS_CAN_MODE_LOOP_BACK;
 956
 957         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 958                 flags |= GS_CAN_MODE_LISTEN_ONLY;
 959
 960         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 961                 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 962
 963         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 964                 flags |= GS_CAN_MODE_ONE_SHOT;
 965
 966         if (ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
 967                 flags |= GS_CAN_MODE_BERR_REPORTING;
 968
 969         if (ctrlmode & CAN_CTRLMODE_FD)
 970                 flags |= GS_CAN_MODE_FD;
 971
 972         /* if hardware supports timestamps, enable it */
 973         if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 974                 flags |= GS_CAN_MODE_HW_TIMESTAMP;
 975
 976         /* finally start device */
 977         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 978         dm.flags = cpu_to_le32(flags);
 979         rc = usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
 980                                   USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 981                                   dev->channel, 0, &dm, sizeof(dm), 1000,
 982                                   GFP_KERNEL);
 983         if (rc) {
 984                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 985                 dev->can.state = CAN_STATE_STOPPED;
 986
 987                 goto out_usb_kill_anchored_urbs;
 988         }
 989
 990         parent->active_channels++;
 991         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 992                 netif_start_queue(netdev);
 993
 994         return 0;
 995
 996 out_usb_unanchor_urb:
 997         usb_unanchor_urb(urb);
 998 out_usb_free_urb:
 999         usb_free_urb(urb);
1000 out_usb_kill_anchored_urbs:
1001         if (!parent->active_channels) {
1002                 usb_kill_anchored_urbs(&dev->tx_submitted);
1003
1004                 if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1005                         gs_usb_timestamp_stop(parent);
1006         }
1007
1008         can_rx_offload_disable(&dev->offload);
1009         close_candev(netdev);
1010
1011         return rc;
1012 }
1013
1014 static int gs_usb_get_state(const struct net_device *netdev,
1015                             struct can_berr_counter *bec,
1016                             enum can_state *state)
1017 {
1018         struct gs_can *dev = netdev_priv(netdev);
1019         struct gs_device_state ds;
1020         int rc;
1021
1022         rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_STATE,
1023                                   USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1024                                   dev->channel, 0,
1025                                   &ds, sizeof(ds),
1026                                   USB_CTRL_GET_TIMEOUT,
1027                                   GFP_KERNEL);
1028         if (rc)
1029                 return rc;
1030
1031         if (le32_to_cpu(ds.state) >= CAN_STATE_MAX)
1032                 return -EOPNOTSUPP;
1033
1034         *state = le32_to_cpu(ds.state);
1035         bec->txerr = le32_to_cpu(ds.txerr);
1036         bec->rxerr = le32_to_cpu(ds.rxerr);
1037
1038         return 0;
1039 }
1040
1041 static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
1042                                        struct can_berr_counter *bec)
1043 {
1044         enum can_state state;
1045
1046         return gs_usb_get_state(netdev, bec, &state);
1047 }
1048
1049 static int gs_can_close(struct net_device *netdev)
1050 {
1051         int rc;
1052         struct gs_can *dev = netdev_priv(netdev);
1053         struct gs_usb *parent = dev->parent;
1054
1055         netif_stop_queue(netdev);
1056
1057         /* Stop polling */
1058         parent->active_channels--;
1059         if (!parent->active_channels) {
1060                 usb_kill_anchored_urbs(&parent->rx_submitted);
1061
1062                 if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1063                         gs_usb_timestamp_stop(parent);
1064         }
1065
1066         /* Stop sending URBs */
1067         usb_kill_anchored_urbs(&dev->tx_submitted);
1068         atomic_set(&dev->active_tx_urbs, 0);
1069
1070         dev->can.state = CAN_STATE_STOPPED;
1071
1072         /* reset the device */
1073         gs_cmd_reset(dev);
1074
1075         /* reset tx contexts */
1076         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1077                 dev->tx_context[rc].dev = dev;
1078                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1079         }
1080
1081         can_rx_offload_disable(&dev->offload);
1082
1083         /* close the netdev */
1084         close_candev(netdev);
1085
1086         return 0;
1087 }
1088
1089 static int gs_can_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1090 {
1091         const struct gs_can *dev = netdev_priv(netdev);
1092
1093         if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1094                 return can_eth_ioctl_hwts(netdev, ifr, cmd);
1095
1096         return -EOPNOTSUPP;
1097 }
1098
1099 static const struct net_device_ops gs_usb_netdev_ops = {
1100         .ndo_open = gs_can_open,
1101         .ndo_stop = gs_can_close,
1102         .ndo_start_xmit = gs_can_start_xmit,
1103         .ndo_change_mtu = can_change_mtu,
1104         .ndo_eth_ioctl = gs_can_eth_ioctl,
1105 };
1106
1107 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
1108 {
1109         struct gs_can *dev = netdev_priv(netdev);
1110         struct gs_identify_mode imode;
1111
1112         if (do_identify)
1113                 imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
1114         else
1115                 imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
1116
1117         return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_IDENTIFY,
1118                                     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1119                                     dev->channel, 0, &imode, sizeof(imode), 100,
1120                                     GFP_KERNEL);
1121 }
1122
1123 /* blink LED's for finding the this interface */
1124 static int gs_usb_set_phys_id(struct net_device *netdev,
1125                               enum ethtool_phys_id_state state)
1126 {
1127         const struct gs_can *dev = netdev_priv(netdev);
1128         int rc = 0;
1129
1130         if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
1131                 return -EOPNOTSUPP;
1132
1133         switch (state) {
1134         case ETHTOOL_ID_ACTIVE:
1135                 rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
1136                 break;
1137         case ETHTOOL_ID_INACTIVE:
1138                 rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
1139                 break;
1140         default:
1141                 break;
1142         }
1143
1144         return rc;
1145 }
1146
1147 static int gs_usb_get_ts_info(struct net_device *netdev,
1148                               struct ethtool_ts_info *info)
1149 {
1150         struct gs_can *dev = netdev_priv(netdev);
1151
1152         /* report if device supports HW timestamps */
1153         if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1154                 return can_ethtool_op_get_ts_info_hwts(netdev, info);
1155
1156         return ethtool_op_get_ts_info(netdev, info);
1157 }
1158
1159 static const struct ethtool_ops gs_usb_ethtool_ops = {
1160         .set_phys_id = gs_usb_set_phys_id,
1161         .get_ts_info = gs_usb_get_ts_info,
1162 };
1163
1164 static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
1165 {
1166         struct gs_can *dev = netdev_priv(netdev);
1167         struct gs_device_termination_state term_state;
1168         int rc;
1169
1170         rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_TERMINATION,
1171                                   USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1172                                   dev->channel, 0,
1173                                   &term_state, sizeof(term_state), 1000,
1174                                   GFP_KERNEL);
1175         if (rc)
1176                 return rc;
1177
1178         if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
1179                 *term = GS_USB_TERMINATION_ENABLED;
1180         else
1181                 *term = GS_USB_TERMINATION_DISABLED;
1182
1183         return 0;
1184 }
1185
1186 static int gs_usb_set_termination(struct net_device *netdev, u16 term)
1187 {
1188         struct gs_can *dev = netdev_priv(netdev);
1189         struct gs_device_termination_state term_state;
1190
1191         if (term == GS_USB_TERMINATION_ENABLED)
1192                 term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
1193         else
1194                 term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
1195
1196         return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_SET_TERMINATION,
1197                                     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1198                                     dev->channel, 0,
1199                                     &term_state, sizeof(term_state), 1000,
1200                                     GFP_KERNEL);
1201 }
1202
1203 static const u16 gs_usb_termination_const[] = {
1204         GS_USB_TERMINATION_DISABLED,
1205         GS_USB_TERMINATION_ENABLED
1206 };
1207
1208 static struct gs_can *gs_make_candev(unsigned int channel,
1209                                      struct usb_interface *intf,
1210                                      struct gs_device_config *dconf)
1211 {
1212         struct gs_can *dev;
1213         struct net_device *netdev;
1214         int rc;
1215         struct gs_device_bt_const_extended bt_const_extended;
1216         struct gs_device_bt_const bt_const;
1217         u32 feature;
1218
1219         /* fetch bit timing constants */
1220         rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1221                                   GS_USB_BREQ_BT_CONST,
1222                                   USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1223                                   channel, 0, &bt_const, sizeof(bt_const), 1000,
1224                                   GFP_KERNEL);
1225
1226         if (rc) {
1227                 dev_err(&intf->dev,
1228                         "Couldn't get bit timing const for channel %d (%pe)\n",
1229                         channel, ERR_PTR(rc));
1230                 return ERR_PTR(rc);
1231         }
1232
1233         /* create netdev */
1234         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
1235         if (!netdev) {
1236                 dev_err(&intf->dev, "Couldn't allocate candev\n");
1237                 return ERR_PTR(-ENOMEM);
1238         }
1239
1240         dev = netdev_priv(netdev);
1241
1242         netdev->netdev_ops = &gs_usb_netdev_ops;
1243         netdev->ethtool_ops = &gs_usb_ethtool_ops;
1244
1245         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
1246         netdev->dev_id = channel;
1247
1248         /* dev setup */
1249         strcpy(dev->bt_const.name, KBUILD_MODNAME);
1250         dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
1251         dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
1252         dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
1253         dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
1254         dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
1255         dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
1256         dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
1257         dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
1258
1259         dev->udev = interface_to_usbdev(intf);
1260         dev->netdev = netdev;
1261         dev->channel = channel;
1262
1263         init_usb_anchor(&dev->tx_submitted);
1264         atomic_set(&dev->active_tx_urbs, 0);
1265         spin_lock_init(&dev->tx_ctx_lock);
1266         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1267                 dev->tx_context[rc].dev = dev;
1268                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1269         }
1270
1271         /* can setup */
1272         dev->can.state = CAN_STATE_STOPPED;
1273         dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
1274         dev->can.bittiming_const = &dev->bt_const;
1275         dev->can.do_set_bittiming = gs_usb_set_bittiming;
1276
1277         dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1278
1279         feature = le32_to_cpu(bt_const.feature);
1280         dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1281         if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1282                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1283
1284         if (feature & GS_CAN_FEATURE_LOOP_BACK)
1285                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1286
1287         if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1288                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1289
1290         if (feature & GS_CAN_FEATURE_ONE_SHOT)
1291                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1292
1293         if (feature & GS_CAN_FEATURE_FD) {
1294                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1295                 /* The data bit timing will be overwritten, if
1296                  * GS_CAN_FEATURE_BT_CONST_EXT is set.
1297                  */
1298                 dev->can.data_bittiming_const = &dev->bt_const;
1299                 dev->can.do_set_data_bittiming = gs_usb_set_data_bittiming;
1300         }
1301
1302         if (feature & GS_CAN_FEATURE_TERMINATION) {
1303                 rc = gs_usb_get_termination(netdev, &dev->can.termination);
1304                 if (rc) {
1305                         dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
1306
1307                         dev_info(&intf->dev,
1308                                  "Disabling termination support for channel %d (%pe)\n",
1309                                  channel, ERR_PTR(rc));
1310                 } else {
1311                         dev->can.termination_const = gs_usb_termination_const;
1312                         dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
1313                         dev->can.do_set_termination = gs_usb_set_termination;
1314                 }
1315         }
1316
1317         if (feature & GS_CAN_FEATURE_BERR_REPORTING)
1318                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
1319
1320         if (feature & GS_CAN_FEATURE_GET_STATE)
1321                 dev->can.do_get_berr_counter = gs_usb_can_get_berr_counter;
1322
1323         /* The CANtact Pro from LinkLayer Labs is based on the
1324          * LPC54616 µC, which is affected by the NXP LPC USB transfer
1325          * erratum. However, the current firmware (version 2) doesn't
1326          * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1327          * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1328          * this issue.
1329          *
1330          * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1331          * CANtact Pro firmware uses a request value, which is already
1332          * used by the candleLight firmware for a different purpose
1333          * (GS_USB_BREQ_GET_USER_ID). Set the feature
1334          * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1335          * issue.
1336          */
1337         if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
1338             dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
1339             dev->udev->manufacturer && dev->udev->product &&
1340             !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1341             !strcmp(dev->udev->product, "CANtact Pro") &&
1342             (le32_to_cpu(dconf->sw_version) <= 2))
1343                 dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1344                         GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1345
1346         /* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
1347         if (!(le32_to_cpu(dconf->sw_version) > 1 &&
1348               feature & GS_CAN_FEATURE_IDENTIFY))
1349                 dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
1350
1351         /* fetch extended bit timing constants if device has feature
1352          * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1353          */
1354         if (feature & GS_CAN_FEATURE_FD &&
1355             feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1356                 rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1357                                           GS_USB_BREQ_BT_CONST_EXT,
1358                                           USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1359                                           channel, 0, &bt_const_extended,
1360                                           sizeof(bt_const_extended),
1361                                           1000, GFP_KERNEL);
1362                 if (rc) {
1363                         dev_err(&intf->dev,
1364                                 "Couldn't get extended bit timing const for channel %d (%pe)\n",
1365                                 channel, ERR_PTR(rc));
1366                         goto out_free_candev;
1367                 }
1368
1369                 strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1370                 dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
1371                 dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
1372                 dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
1373                 dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
1374                 dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
1375                 dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
1376                 dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
1377                 dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
1378
1379                 dev->can.data_bittiming_const = &dev->data_bt_const;
1380         }
1381
1382         can_rx_offload_add_manual(netdev, &dev->offload, GS_NAPI_WEIGHT);
1383         SET_NETDEV_DEV(netdev, &intf->dev);
1384
1385         rc = register_candev(dev->netdev);
1386         if (rc) {
1387                 dev_err(&intf->dev,
1388                         "Couldn't register candev for channel %d (%pe)\n",
1389                         channel, ERR_PTR(rc));
1390                 goto out_can_rx_offload_del;
1391         }
1392
1393         return dev;
1394
1395 out_can_rx_offload_del:
1396         can_rx_offload_del(&dev->offload);
1397 out_free_candev:
1398         free_candev(dev->netdev);
1399         return ERR_PTR(rc);
1400 }
1401
1402 static void gs_destroy_candev(struct gs_can *dev)
1403 {
1404         unregister_candev(dev->netdev);
1405         can_rx_offload_del(&dev->offload);
1406         free_candev(dev->netdev);
1407 }
1408
1409 static int gs_usb_probe(struct usb_interface *intf,
1410                         const struct usb_device_id *id)
1411 {
1412         struct usb_device *udev = interface_to_usbdev(intf);
1413         struct gs_host_frame *hf;
1414         struct gs_usb *parent;
1415         struct gs_host_config hconf = {
1416                 .byte_order = cpu_to_le32(0x0000beef),
1417         };
1418         struct gs_device_config dconf;
1419         unsigned int icount, i;
1420         int rc;
1421
1422         /* send host config */
1423         rc = usb_control_msg_send(udev, 0,
1424                                   GS_USB_BREQ_HOST_FORMAT,
1425                                   USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1426                                   1, intf->cur_altsetting->desc.bInterfaceNumber,
1427                                   &hconf, sizeof(hconf), 1000,
1428                                   GFP_KERNEL);
1429         if (rc) {
1430                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1431                 return rc;
1432         }
1433
1434         /* read device config */
1435         rc = usb_control_msg_recv(udev, 0,
1436                                   GS_USB_BREQ_DEVICE_CONFIG,
1437                                   USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1438                                   1, intf->cur_altsetting->desc.bInterfaceNumber,
1439                                   &dconf, sizeof(dconf), 1000,
1440                                   GFP_KERNEL);
1441         if (rc) {
1442                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1443                         rc);
1444                 return rc;
1445         }
1446
1447         icount = dconf.icount + 1;
1448         dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1449
1450         if (icount > GS_MAX_INTF) {
1451                 dev_err(&intf->dev,
1452                         "Driver cannot handle more that %u CAN interfaces\n",
1453                         GS_MAX_INTF);
1454                 return -EINVAL;
1455         }
1456
1457         parent = kzalloc(sizeof(*parent), GFP_KERNEL);
1458         if (!parent)
1459                 return -ENOMEM;
1460
1461         init_usb_anchor(&parent->rx_submitted);
1462
1463         usb_set_intfdata(intf, parent);
1464         parent->udev = udev;
1465
1466         for (i = 0; i < icount; i++) {
1467                 unsigned int hf_size_rx = 0;
1468
1469                 parent->canch[i] = gs_make_candev(i, intf, &dconf);
1470                 if (IS_ERR_OR_NULL(parent->canch[i])) {
1471                         /* save error code to return later */
1472                         rc = PTR_ERR(parent->canch[i]);
1473
1474                         /* on failure destroy previously created candevs */
1475                         icount = i;
1476                         for (i = 0; i < icount; i++)
1477                                 gs_destroy_candev(parent->canch[i]);
1478
1479                         usb_kill_anchored_urbs(&parent->rx_submitted);
1480                         kfree(parent);
1481                         return rc;
1482                 }
1483                 parent->canch[i]->parent = parent;
1484
1485                 /* set RX packet size based on FD and if hardware
1486                  * timestamps are supported.
1487                  */
1488                 if (parent->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1489                         if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1490                                 hf_size_rx = struct_size(hf, canfd_ts, 1);
1491                         else
1492                                 hf_size_rx = struct_size(hf, canfd, 1);
1493                 } else {
1494                         if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1495                                 hf_size_rx = struct_size(hf, classic_can_ts, 1);
1496                         else
1497                                 hf_size_rx = struct_size(hf, classic_can, 1);
1498                 }
1499                 parent->hf_size_rx = max(parent->hf_size_rx, hf_size_rx);
1500         }
1501
1502         return 0;
1503 }
1504
1505 static void gs_usb_disconnect(struct usb_interface *intf)
1506 {
1507         struct gs_usb *parent = usb_get_intfdata(intf);
1508         unsigned int i;
1509
1510         usb_set_intfdata(intf, NULL);
1511
1512         if (!parent) {
1513                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1514                 return;
1515         }
1516
1517         for (i = 0; i < GS_MAX_INTF; i++)
1518                 if (parent->canch[i])
1519                         gs_destroy_candev(parent->canch[i]);
1520
1521         kfree(parent);
1522 }
1523
1524 static const struct usb_device_id gs_usb_table[] = {
1525         { USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
1526                                       USB_GS_USB_1_PRODUCT_ID, 0) },
1527         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1528                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1529         { USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1530                                       USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1531         { USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1532                                       USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1533         {} /* Terminating entry */
1534 };
1535
1536 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1537
1538 static struct usb_driver gs_usb_driver = {
1539         .name = KBUILD_MODNAME,
1540         .probe = gs_usb_probe,
1541         .disconnect = gs_usb_disconnect,
1542         .id_table = gs_usb_table,
1543 };
1544
1545 module_usb_driver(gs_usb_driver);
1546
1547 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1548 MODULE_DESCRIPTION(
1549 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1550 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1551 "and bytewerk.org candleLight USB CAN interfaces.");
1552 MODULE_LICENSE("GPL v2");