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 USB_XYLANTA_SAINT3_VENDOR_ID 0x16d0
  44#define USB_XYLANTA_SAINT3_PRODUCT_ID 0x0f30
  45
  46#define USB_CANNECTIVITY_VENDOR_ID 0x1209
  47#define USB_CANNECTIVITY_PRODUCT_ID 0xca01
  48
  49/* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
  50 * for timer overflow (will be after ~71 minutes)
  51 */
  52#define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
  53#define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
  54static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
  55	      CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
  56
  57/* Device specific constants */
  58enum gs_usb_breq {
  59	GS_USB_BREQ_HOST_FORMAT = 0,
  60	GS_USB_BREQ_BITTIMING,
  61	GS_USB_BREQ_MODE,
  62	GS_USB_BREQ_BERR,
  63	GS_USB_BREQ_BT_CONST,
  64	GS_USB_BREQ_DEVICE_CONFIG,
  65	GS_USB_BREQ_TIMESTAMP,
  66	GS_USB_BREQ_IDENTIFY,
  67	GS_USB_BREQ_GET_USER_ID,
  68	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
  69	GS_USB_BREQ_SET_USER_ID,
  70	GS_USB_BREQ_DATA_BITTIMING,
  71	GS_USB_BREQ_BT_CONST_EXT,
  72	GS_USB_BREQ_SET_TERMINATION,
  73	GS_USB_BREQ_GET_TERMINATION,
  74	GS_USB_BREQ_GET_STATE,
  75};
  76
  77enum gs_can_mode {
  78	/* reset a channel. turns it off */
  79	GS_CAN_MODE_RESET = 0,
  80	/* starts a channel */
  81	GS_CAN_MODE_START
  82};
  83
  84enum gs_can_state {
  85	GS_CAN_STATE_ERROR_ACTIVE = 0,
  86	GS_CAN_STATE_ERROR_WARNING,
  87	GS_CAN_STATE_ERROR_PASSIVE,
  88	GS_CAN_STATE_BUS_OFF,
  89	GS_CAN_STATE_STOPPED,
  90	GS_CAN_STATE_SLEEPING
  91};
  92
  93enum gs_can_identify_mode {
  94	GS_CAN_IDENTIFY_OFF = 0,
  95	GS_CAN_IDENTIFY_ON
  96};
  97
  98enum gs_can_termination_state {
  99	GS_CAN_TERMINATION_STATE_OFF = 0,
 100	GS_CAN_TERMINATION_STATE_ON
 101};
 102
 103#define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
 104#define GS_USB_TERMINATION_ENABLED 120
 105
 106/* data types passed between host and device */
 107
 108/* The firmware on the original USB2CAN by Geschwister Schneider
 109 * Technologie Entwicklungs- und Vertriebs UG exchanges all data
 110 * between the host and the device in host byte order. This is done
 111 * with the struct gs_host_config::byte_order member, which is sent
 112 * first to indicate the desired byte order.
 113 *
 114 * The widely used open source firmware candleLight doesn't support
 115 * this feature and exchanges the data in little endian byte order.
 116 */
 117struct gs_host_config {
 118	__le32 byte_order;
 119} __packed;
 120
 121struct gs_device_config {
 122	u8 reserved1;
 123	u8 reserved2;
 124	u8 reserved3;
 125	u8 icount;
 126	__le32 sw_version;
 127	__le32 hw_version;
 128} __packed;
 129
 130#define GS_CAN_MODE_NORMAL 0
 131#define GS_CAN_MODE_LISTEN_ONLY BIT(0)
 132#define GS_CAN_MODE_LOOP_BACK BIT(1)
 133#define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
 134#define GS_CAN_MODE_ONE_SHOT BIT(3)
 135#define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
 136/* GS_CAN_FEATURE_IDENTIFY BIT(5) */
 137/* GS_CAN_FEATURE_USER_ID BIT(6) */
 138#define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
 139#define GS_CAN_MODE_FD BIT(8)
 140/* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
 141/* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
 142/* GS_CAN_FEATURE_TERMINATION BIT(11) */
 143#define GS_CAN_MODE_BERR_REPORTING BIT(12)
 144/* GS_CAN_FEATURE_GET_STATE BIT(13) */
 145
 146struct gs_device_mode {
 147	__le32 mode;
 148	__le32 flags;
 149} __packed;
 150
 151struct gs_device_state {
 152	__le32 state;
 153	__le32 rxerr;
 154	__le32 txerr;
 155} __packed;
 156
 157struct gs_device_bittiming {
 158	__le32 prop_seg;
 159	__le32 phase_seg1;
 160	__le32 phase_seg2;
 161	__le32 sjw;
 162	__le32 brp;
 163} __packed;
 164
 165struct gs_identify_mode {
 166	__le32 mode;
 167} __packed;
 168
 169struct gs_device_termination_state {
 170	__le32 state;
 171} __packed;
 172
 173#define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
 174#define GS_CAN_FEATURE_LOOP_BACK BIT(1)
 175#define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
 176#define GS_CAN_FEATURE_ONE_SHOT BIT(3)
 177#define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
 178#define GS_CAN_FEATURE_IDENTIFY BIT(5)
 179#define GS_CAN_FEATURE_USER_ID BIT(6)
 180#define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
 181#define GS_CAN_FEATURE_FD BIT(8)
 182#define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
 183#define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
 184#define GS_CAN_FEATURE_TERMINATION BIT(11)
 185#define GS_CAN_FEATURE_BERR_REPORTING BIT(12)
 186#define GS_CAN_FEATURE_GET_STATE BIT(13)
 187#define GS_CAN_FEATURE_MASK GENMASK(13, 0)
 188
 189/* internal quirks - keep in GS_CAN_FEATURE space for now */
 190
 191/* CANtact Pro original firmware:
 192 * BREQ DATA_BITTIMING overlaps with GET_USER_ID
 193 */
 194#define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
 195
 196struct gs_device_bt_const {
 197	__le32 feature;
 198	__le32 fclk_can;
 199	__le32 tseg1_min;
 200	__le32 tseg1_max;
 201	__le32 tseg2_min;
 202	__le32 tseg2_max;
 203	__le32 sjw_max;
 204	__le32 brp_min;
 205	__le32 brp_max;
 206	__le32 brp_inc;
 207} __packed;
 208
 209struct gs_device_bt_const_extended {
 210	__le32 feature;
 211	__le32 fclk_can;
 212	__le32 tseg1_min;
 213	__le32 tseg1_max;
 214	__le32 tseg2_min;
 215	__le32 tseg2_max;
 216	__le32 sjw_max;
 217	__le32 brp_min;
 218	__le32 brp_max;
 219	__le32 brp_inc;
 220
 221	__le32 dtseg1_min;
 222	__le32 dtseg1_max;
 223	__le32 dtseg2_min;
 224	__le32 dtseg2_max;
 225	__le32 dsjw_max;
 226	__le32 dbrp_min;
 227	__le32 dbrp_max;
 228	__le32 dbrp_inc;
 229} __packed;
 230
 231#define GS_CAN_FLAG_OVERFLOW BIT(0)
 232#define GS_CAN_FLAG_FD BIT(1)
 233#define GS_CAN_FLAG_BRS BIT(2)
 234#define GS_CAN_FLAG_ESI BIT(3)
 235
 236struct classic_can {
 237	u8 data[8];
 238} __packed;
 239
 240struct classic_can_ts {
 241	u8 data[8];
 242	__le32 timestamp_us;
 243} __packed;
 244
 245struct classic_can_quirk {
 246	u8 data[8];
 247	u8 quirk;
 248} __packed;
 249
 250struct canfd {
 251	u8 data[64];
 252} __packed;
 253
 254struct canfd_ts {
 255	u8 data[64];
 256	__le32 timestamp_us;
 257} __packed;
 258
 259struct canfd_quirk {
 260	u8 data[64];
 261	u8 quirk;
 262} __packed;
 263
 264/* struct gs_host_frame::echo_id == GS_HOST_FRAME_ECHO_ID_RX indicates
 265 * a regular RX'ed CAN frame
 266 */
 267#define GS_HOST_FRAME_ECHO_ID_RX 0xffffffff
 268
 269struct gs_host_frame {
 270	struct_group(header,
 271		u32 echo_id;
 272		__le32 can_id;
 273
 274		u8 can_dlc;
 275		u8 channel;
 276		u8 flags;
 277		u8 reserved;
 278	);
 279
 280	union {
 281		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
 282		DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
 283		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
 284		DECLARE_FLEX_ARRAY(struct canfd, canfd);
 285		DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
 286		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
 287	};
 288} __packed;
 289/* The GS USB devices make use of the same flags and masks as in
 290 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 291 */
 292
 293/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 294#define GS_MAX_TX_URBS 10
 295/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 296#define GS_MAX_RX_URBS 30
 297#define GS_NAPI_WEIGHT 32
 298
 299struct gs_tx_context {
 300	struct gs_can *dev;
 301	unsigned int echo_id;
 302};
 303
 304struct gs_can {
 305	struct can_priv can; /* must be the first member */
 306
 307	struct can_rx_offload offload;
 308	struct gs_usb *parent;
 309
 310	struct net_device *netdev;
 311	struct usb_device *udev;
 312
 313	struct can_bittiming_const bt_const, data_bt_const;
 314	unsigned int channel;	/* channel number */
 315
 316	u32 feature;
 317	unsigned int hf_size_tx;
 318
 319	/* This lock prevents a race condition between xmit and receive. */
 320	spinlock_t tx_ctx_lock;
 321	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 322
 323	struct usb_anchor tx_submitted;
 324	atomic_t active_tx_urbs;
 325};
 326
 327/* usb interface struct */
 328struct gs_usb {
 329	struct usb_anchor rx_submitted;
 330	struct usb_device *udev;
 331
 332	/* time counter for hardware timestamps */
 333	struct cyclecounter cc;
 334	struct timecounter tc;
 335	spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
 336	struct delayed_work timestamp;
 337
 338	unsigned int hf_size_rx;
 339	u8 active_channels;
 340	u8 channel_cnt;
 341
 342	unsigned int pipe_in;
 343	unsigned int pipe_out;
 344	struct gs_can *canch[] __counted_by(channel_cnt);
 345};
 346
 347/* 'allocate' a tx context.
 348 * returns a valid tx context or NULL if there is no space.
 349 */
 350static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 351{
 352	int i = 0;
 353	unsigned long flags;
 354
 355	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 356
 357	for (; i < GS_MAX_TX_URBS; i++) {
 358		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 359			dev->tx_context[i].echo_id = i;
 360			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 361			return &dev->tx_context[i];
 362		}
 363	}
 364
 365	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 366	return NULL;
 367}
 368
 369/* releases a tx context
 370 */
 371static void gs_free_tx_context(struct gs_tx_context *txc)
 372{
 373	txc->echo_id = GS_MAX_TX_URBS;
 374}
 375
 376/* Get a tx context by id.
 377 */
 378static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
 379					       unsigned int id)
 380{
 381	unsigned long flags;
 382
 383	if (id < GS_MAX_TX_URBS) {
 384		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 385		if (dev->tx_context[id].echo_id == id) {
 386			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 387			return &dev->tx_context[id];
 388		}
 389		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 390	}
 391	return NULL;
 392}
 393
 394static int gs_cmd_reset(struct gs_can *dev)
 395{
 396	struct gs_device_mode dm = {
 397		.mode = cpu_to_le32(GS_CAN_MODE_RESET),
 398	};
 399
 400	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
 401				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 402				    dev->channel, 0, &dm, sizeof(dm), 1000,
 403				    GFP_KERNEL);
 404}
 405
 406static inline int gs_usb_get_timestamp(const struct gs_usb *parent,
 407				       u32 *timestamp_p)
 408{
 409	__le32 timestamp;
 410	int rc;
 411
 412	rc = usb_control_msg_recv(parent->udev, 0, GS_USB_BREQ_TIMESTAMP,
 413				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 414				  0, 0,
 415				  &timestamp, sizeof(timestamp),
 416				  USB_CTRL_GET_TIMEOUT,
 417				  GFP_KERNEL);
 418	if (rc)
 419		return rc;
 420
 421	*timestamp_p = le32_to_cpu(timestamp);
 422
 423	return 0;
 424}
 425
 426static u64 gs_usb_timestamp_read(struct cyclecounter *cc) __must_hold(&dev->tc_lock)
 427{
 428	struct gs_usb *parent = container_of(cc, struct gs_usb, cc);
 429	u32 timestamp = 0;
 430	int err;
 431
 432	lockdep_assert_held(&parent->tc_lock);
 433
 434	/* drop lock for synchronous USB transfer */
 435	spin_unlock_bh(&parent->tc_lock);
 436	err = gs_usb_get_timestamp(parent, &timestamp);
 437	spin_lock_bh(&parent->tc_lock);
 438	if (err)
 439		dev_err(&parent->udev->dev,
 440			"Error %d while reading timestamp. HW timestamps may be inaccurate.",
 441			err);
 442
 443	return timestamp;
 444}
 445
 446static void gs_usb_timestamp_work(struct work_struct *work)
 447{
 448	struct delayed_work *delayed_work = to_delayed_work(work);
 449	struct gs_usb *parent;
 450
 451	parent = container_of(delayed_work, struct gs_usb, timestamp);
 452	spin_lock_bh(&parent->tc_lock);
 453	timecounter_read(&parent->tc);
 454	spin_unlock_bh(&parent->tc_lock);
 455
 456	schedule_delayed_work(&parent->timestamp,
 457			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
 458}
 459
 460static void gs_usb_skb_set_timestamp(struct gs_can *dev,
 461				     struct sk_buff *skb, u32 timestamp)
 462{
 463	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
 464	struct gs_usb *parent = dev->parent;
 465	u64 ns;
 466
 467	spin_lock_bh(&parent->tc_lock);
 468	ns = timecounter_cyc2time(&parent->tc, timestamp);
 469	spin_unlock_bh(&parent->tc_lock);
 470
 471	hwtstamps->hwtstamp = ns_to_ktime(ns);
 472}
 473
 474static void gs_usb_timestamp_init(struct gs_usb *parent)
 475{
 476	struct cyclecounter *cc = &parent->cc;
 477
 478	cc->read = gs_usb_timestamp_read;
 479	cc->mask = CYCLECOUNTER_MASK(32);
 480	cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
 481	cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
 482
 483	spin_lock_init(&parent->tc_lock);
 484	spin_lock_bh(&parent->tc_lock);
 485	timecounter_init(&parent->tc, &parent->cc, ktime_get_real_ns());
 486	spin_unlock_bh(&parent->tc_lock);
 487
 488	INIT_DELAYED_WORK(&parent->timestamp, gs_usb_timestamp_work);
 489	schedule_delayed_work(&parent->timestamp,
 490			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
 491}
 492
 493static void gs_usb_timestamp_stop(struct gs_usb *parent)
 494{
 495	cancel_delayed_work_sync(&parent->timestamp);
 496}
 497
 498static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 499{
 500	struct can_device_stats *can_stats = &dev->can.can_stats;
 501
 502	if (cf->can_id & CAN_ERR_RESTARTED) {
 503		dev->can.state = CAN_STATE_ERROR_ACTIVE;
 504		can_stats->restarts++;
 505	} else if (cf->can_id & CAN_ERR_BUSOFF) {
 506		dev->can.state = CAN_STATE_BUS_OFF;
 507		can_stats->bus_off++;
 508	} else if (cf->can_id & CAN_ERR_CRTL) {
 509		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 510		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 511			dev->can.state = CAN_STATE_ERROR_WARNING;
 512			can_stats->error_warning++;
 513		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 514			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 515			dev->can.state = CAN_STATE_ERROR_PASSIVE;
 516			can_stats->error_passive++;
 517		} else {
 518			dev->can.state = CAN_STATE_ERROR_ACTIVE;
 519		}
 520	}
 521}
 522
 523static u32 gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
 524				const struct gs_host_frame *hf)
 525{
 526	u32 timestamp;
 527
 528	if (hf->flags & GS_CAN_FLAG_FD)
 529		timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
 530	else
 531		timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
 532
 533	if (skb)
 534		gs_usb_skb_set_timestamp(dev, skb, timestamp);
 535
 536	return timestamp;
 537}
 538
 539static void gs_usb_rx_offload(struct gs_can *dev, struct sk_buff *skb,
 540			      const struct gs_host_frame *hf)
 541{
 542	struct can_rx_offload *offload = &dev->offload;
 543	int rc;
 544
 545	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
 546		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
 547
 548		rc = can_rx_offload_queue_timestamp(offload, skb, ts);
 549	} else {
 550		rc = can_rx_offload_queue_tail(offload, skb);
 551	}
 552
 553	if (rc)
 554		dev->netdev->stats.rx_fifo_errors++;
 555}
 556
 557static unsigned int
 558gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb,
 559		    const struct gs_host_frame *hf)
 560{
 561	struct can_rx_offload *offload = &dev->offload;
 562	const u32 echo_id = hf->echo_id;
 563	unsigned int len;
 564
 565	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
 566		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
 567
 568		len = can_rx_offload_get_echo_skb_queue_timestamp(offload, echo_id,
 569								  ts, NULL);
 570	} else {
 571		len = can_rx_offload_get_echo_skb_queue_tail(offload, echo_id,
 572							     NULL);
 573	}
 574
 575	return len;
 576}
 577
 578static unsigned int
 579gs_usb_get_minimum_rx_length(const struct gs_can *dev, const struct gs_host_frame *hf,
 580			     unsigned int *data_length_p)
 581{
 582	unsigned int minimum_length, data_length = 0;
 583
 584	if (hf->flags & GS_CAN_FLAG_FD) {
 585		if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX)
 586			data_length = can_fd_dlc2len(hf->can_dlc);
 587
 588		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 589			/* timestamp follows data field of max size */
 590			minimum_length = struct_size(hf, canfd_ts, 1);
 591		else
 592			minimum_length = sizeof(hf->header) + data_length;
 593	} else {
 594		if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX &&
 595		    !(hf->can_id & cpu_to_le32(CAN_RTR_FLAG)))
 596			data_length = can_cc_dlc2len(hf->can_dlc);
 597
 598		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 599			/* timestamp follows data field of max size */
 600			minimum_length = struct_size(hf, classic_can_ts, 1);
 601		else
 602			minimum_length = sizeof(hf->header) + data_length;
 603	}
 604
 605	*data_length_p = data_length;
 606	return minimum_length;
 607}
 608
 609static void gs_usb_receive_bulk_callback(struct urb *urb)
 610{
 611	struct gs_usb *parent = urb->context;
 612	struct gs_can *dev;
 613	struct net_device *netdev = NULL;
 614	int rc;
 615	struct net_device_stats *stats;
 616	struct gs_host_frame *hf = urb->transfer_buffer;
 617	unsigned int minimum_length, data_length;
 618	struct gs_tx_context *txc;
 619	struct can_frame *cf;
 620	struct canfd_frame *cfd;
 621	struct sk_buff *skb;
 622
 623	BUG_ON(!parent);
 624
 625	switch (urb->status) {
 626	case 0: /* success */
 627		break;
 628	case -ENOENT:
 629	case -ESHUTDOWN:
 630		return;
 631	default:
 632		/* do not resubmit aborted urbs. eg: when device goes down */
 633		return;
 634	}
 635
 636	minimum_length = sizeof(hf->header);
 637	if (urb->actual_length < minimum_length) {
 638		dev_err_ratelimited(&parent->udev->dev,
 639				    "short read (actual_length=%u, minimum_length=%u)\n",
 640				    urb->actual_length, minimum_length);
 641
 642		goto resubmit_urb;
 643	}
 644
 645	/* device reports out of range channel id */
 646	if (hf->channel >= parent->channel_cnt)
 647		goto device_detach;
 648
 649	dev = parent->canch[hf->channel];
 650
 651	netdev = dev->netdev;
 652	stats = &netdev->stats;
 653
 654	if (!netif_device_present(netdev))
 655		return;
 656
 657	if (!netif_running(netdev))
 658		goto resubmit_urb;
 659
 660	minimum_length = gs_usb_get_minimum_rx_length(dev, hf, &data_length);
 661	if (urb->actual_length < minimum_length) {
 662		stats->rx_errors++;
 663		stats->rx_length_errors++;
 664
 665		if (net_ratelimit())
 666			netdev_err(netdev,
 667				   "short read (actual_length=%u, minimum_length=%u)\n",
 668				   urb->actual_length, minimum_length);
 669
 670		goto resubmit_urb;
 671	}
 672
 673	if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) { /* normal rx */
 674		if (hf->flags & GS_CAN_FLAG_FD) {
 675			skb = alloc_canfd_skb(netdev, &cfd);
 676			if (!skb)
 677				return;
 678
 679			cfd->can_id = le32_to_cpu(hf->can_id);
 680			cfd->len = data_length;
 681			if (hf->flags & GS_CAN_FLAG_BRS)
 682				cfd->flags |= CANFD_BRS;
 683			if (hf->flags & GS_CAN_FLAG_ESI)
 684				cfd->flags |= CANFD_ESI;
 685
 686			memcpy(cfd->data, hf->canfd->data, data_length);
 687		} else {
 688			skb = alloc_can_skb(netdev, &cf);
 689			if (!skb)
 690				return;
 691
 692			cf->can_id = le32_to_cpu(hf->can_id);
 693			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
 694
 695			memcpy(cf->data, hf->classic_can->data, data_length);
 696
 697			/* ERROR frames tell us information about the controller */
 698			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
 699				gs_update_state(dev, cf);
 700		}
 701
 702		gs_usb_rx_offload(dev, skb, hf);
 703	} else { /* echo_id == hf->echo_id */
 704		if (hf->echo_id >= GS_MAX_TX_URBS) {
 705			netdev_err(netdev,
 706				   "Unexpected out of range echo id %u\n",
 707				   hf->echo_id);
 708			goto resubmit_urb;
 709		}
 710
 711		txc = gs_get_tx_context(dev, hf->echo_id);
 712
 713		/* bad devices send bad echo_ids. */
 714		if (!txc) {
 715			netdev_err(netdev,
 716				   "Unexpected unused echo id %u\n",
 717				   hf->echo_id);
 718			goto resubmit_urb;
 719		}
 720
 721		skb = dev->can.echo_skb[hf->echo_id];
 722		stats->tx_packets++;
 723		stats->tx_bytes += gs_usb_get_echo_skb(dev, skb, hf);
 724		gs_free_tx_context(txc);
 725
 726		atomic_dec(&dev->active_tx_urbs);
 727
 728		netif_wake_queue(netdev);
 729	}
 730
 731	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 732		stats->rx_over_errors++;
 733		stats->rx_errors++;
 734
 735		skb = alloc_can_err_skb(netdev, &cf);
 736		if (!skb)
 737			goto resubmit_urb;
 738
 739		cf->can_id |= CAN_ERR_CRTL;
 740		cf->len = CAN_ERR_DLC;
 741		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 742
 743		gs_usb_rx_offload(dev, skb, hf);
 744	}
 745
 746	can_rx_offload_irq_finish(&dev->offload);
 747
 748resubmit_urb:
 749	usb_fill_bulk_urb(urb, parent->udev,
 750			  parent->pipe_in,
 751			  hf, parent->hf_size_rx,
 752			  gs_usb_receive_bulk_callback, parent);
 753
 754	usb_anchor_urb(urb, &parent->rx_submitted);
 755
 756	rc = usb_submit_urb(urb, GFP_ATOMIC);
 757	if (!rc)
 758		return;
 759
 760	usb_unanchor_urb(urb);
 761
 762	/* USB failure take down all interfaces */
 763	if (rc == -ENODEV) {
 764device_detach:
 765		for (rc = 0; rc < parent->channel_cnt; rc++) {
 766			if (parent->canch[rc])
 767				netif_device_detach(parent->canch[rc]->netdev);
 768		}
 769	} else if (rc != -ESHUTDOWN && net_ratelimit()) {
 770		netdev_info(netdev, "failed to re-submit IN URB: %pe\n",
 771			    ERR_PTR(rc));
 772	}
 773}
 774
 775static int gs_usb_set_bittiming(struct gs_can *dev)
 776{
 777	struct can_bittiming *bt = &dev->can.bittiming;
 778	struct gs_device_bittiming dbt = {
 779		.prop_seg = cpu_to_le32(bt->prop_seg),
 780		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
 781		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
 782		.sjw = cpu_to_le32(bt->sjw),
 783		.brp = cpu_to_le32(bt->brp),
 784	};
 785
 786	/* request bit timings */
 787	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_BITTIMING,
 788				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 789				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
 790				    GFP_KERNEL);
 791}
 792
 793static int gs_usb_set_data_bittiming(struct gs_can *dev)
 794{
 795	struct can_bittiming *bt = &dev->can.fd.data_bittiming;
 796	struct gs_device_bittiming dbt = {
 797		.prop_seg = cpu_to_le32(bt->prop_seg),
 798		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
 799		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
 800		.sjw = cpu_to_le32(bt->sjw),
 801		.brp = cpu_to_le32(bt->brp),
 802	};
 803	u8 request = GS_USB_BREQ_DATA_BITTIMING;
 804
 805	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
 806		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
 807
 808	/* request data bit timings */
 809	return usb_control_msg_send(dev->udev, 0, request,
 810				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 811				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
 812				    GFP_KERNEL);
 813}
 814
 815static void gs_usb_xmit_callback(struct urb *urb)
 816{
 817	struct gs_tx_context *txc = urb->context;
 818	struct gs_can *dev = txc->dev;
 819	struct net_device *netdev = dev->netdev;
 820
 821	if (!urb->status)
 822		return;
 823
 824	if (urb->status != -ESHUTDOWN && net_ratelimit())
 825		netdev_info(netdev, "failed to xmit URB %u: %pe\n",
 826			    txc->echo_id, ERR_PTR(urb->status));
 827
 828	netdev->stats.tx_dropped++;
 829	netdev->stats.tx_errors++;
 830
 831	can_free_echo_skb(netdev, txc->echo_id, NULL);
 832	gs_free_tx_context(txc);
 833	atomic_dec(&dev->active_tx_urbs);
 834
 835	netif_wake_queue(netdev);
 836}
 837
 838static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 839				     struct net_device *netdev)
 840{
 841	struct gs_can *dev = netdev_priv(netdev);
 842	struct net_device_stats *stats = &dev->netdev->stats;
 843	struct urb *urb;
 844	struct gs_host_frame *hf;
 845	struct can_frame *cf;
 846	struct canfd_frame *cfd;
 847	int rc;
 848	unsigned int idx;
 849	struct gs_tx_context *txc;
 850
 851	if (can_dev_dropped_skb(netdev, skb))
 852		return NETDEV_TX_OK;
 853
 854	/* find an empty context to keep track of transmission */
 855	txc = gs_alloc_tx_context(dev);
 856	if (!txc)
 857		return NETDEV_TX_BUSY;
 858
 859	/* create a URB, and a buffer for it */
 860	urb = usb_alloc_urb(0, GFP_ATOMIC);
 861	if (!urb)
 862		goto nomem_urb;
 863
 864	hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
 865	if (!hf)
 866		goto nomem_hf;
 867
 868	idx = txc->echo_id;
 869
 870	if (idx >= GS_MAX_TX_URBS) {
 871		netdev_err(netdev, "Invalid tx context %u\n", idx);
 872		goto badidx;
 873	}
 874
 875	hf->echo_id = idx;
 876	hf->channel = dev->channel;
 877	hf->flags = 0;
 878	hf->reserved = 0;
 879
 880	if (can_is_canfd_skb(skb)) {
 881		cfd = (struct canfd_frame *)skb->data;
 882
 883		hf->can_id = cpu_to_le32(cfd->can_id);
 884		hf->can_dlc = can_fd_len2dlc(cfd->len);
 885		hf->flags |= GS_CAN_FLAG_FD;
 886		if (cfd->flags & CANFD_BRS)
 887			hf->flags |= GS_CAN_FLAG_BRS;
 888		if (cfd->flags & CANFD_ESI)
 889			hf->flags |= GS_CAN_FLAG_ESI;
 890
 891		memcpy(hf->canfd->data, cfd->data, cfd->len);
 892	} else {
 893		cf = (struct can_frame *)skb->data;
 894
 895		hf->can_id = cpu_to_le32(cf->can_id);
 896		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
 897
 898		memcpy(hf->classic_can->data, cf->data, cf->len);
 899	}
 900
 901	usb_fill_bulk_urb(urb, dev->udev,
 902			  dev->parent->pipe_out,
 903			  hf, dev->hf_size_tx,
 904			  gs_usb_xmit_callback, txc);
 905
 906	urb->transfer_flags |= URB_FREE_BUFFER;
 907	usb_anchor_urb(urb, &dev->tx_submitted);
 908
 909	can_put_echo_skb(skb, netdev, idx, 0);
 910
 911	atomic_inc(&dev->active_tx_urbs);
 912
 913	rc = usb_submit_urb(urb, GFP_ATOMIC);
 914	if (unlikely(rc)) {			/* usb send failed */
 915		atomic_dec(&dev->active_tx_urbs);
 916
 917		can_free_echo_skb(netdev, idx, NULL);
 918		gs_free_tx_context(txc);
 919
 920		usb_unanchor_urb(urb);
 921
 922		if (rc == -ENODEV) {
 923			netif_device_detach(netdev);
 924		} else {
 925			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 926			stats->tx_dropped++;
 927		}
 928	} else {
 929		/* Slow down tx path */
 930		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 931			netif_stop_queue(netdev);
 932	}
 933
 934	/* let usb core take care of this urb */
 935	usb_free_urb(urb);
 936
 937	return NETDEV_TX_OK;
 938
 939badidx:
 940	kfree(hf);
 941nomem_hf:
 942	usb_free_urb(urb);
 943
 944nomem_urb:
 945	gs_free_tx_context(txc);
 946	dev_kfree_skb(skb);
 947	stats->tx_dropped++;
 948	return NETDEV_TX_OK;
 949}
 950
 951static int gs_can_open(struct net_device *netdev)
 952{
 953	struct gs_can *dev = netdev_priv(netdev);
 954	struct gs_usb *parent = dev->parent;
 955	struct gs_device_mode dm = {
 956		.mode = cpu_to_le32(GS_CAN_MODE_START),
 957	};
 958	struct gs_host_frame *hf;
 959	struct urb *urb = NULL;
 960	u32 ctrlmode;
 961	u32 flags = 0;
 962	int rc, i;
 963
 964	rc = open_candev(netdev);
 965	if (rc)
 966		return rc;
 967
 968	ctrlmode = dev->can.ctrlmode;
 969	if (ctrlmode & CAN_CTRLMODE_FD) {
 970		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
 971			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
 972		else
 973			dev->hf_size_tx = struct_size(hf, canfd, 1);
 974	} else {
 975		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
 976			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
 977		else
 978			dev->hf_size_tx = struct_size(hf, classic_can, 1);
 979	}
 980
 981	can_rx_offload_enable(&dev->offload);
 982
 983	if (!parent->active_channels) {
 984		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 985			gs_usb_timestamp_init(parent);
 986
 987		for (i = 0; i < GS_MAX_RX_URBS; i++) {
 988			u8 *buf;
 989
 990			/* alloc rx urb */
 991			urb = usb_alloc_urb(0, GFP_KERNEL);
 992			if (!urb) {
 993				rc = -ENOMEM;
 994				goto out_usb_kill_anchored_urbs;
 995			}
 996
 997			/* alloc rx buffer */
 998			buf = kmalloc(dev->parent->hf_size_rx,
 999				      GFP_KERNEL);
1000			if (!buf) {
1001				rc = -ENOMEM;
1002				goto out_usb_free_urb;
1003			}
1004
1005			/* fill, anchor, and submit rx urb */
1006			usb_fill_bulk_urb(urb,
1007					  dev->udev,
1008					  dev->parent->pipe_in,
1009					  buf,
1010					  dev->parent->hf_size_rx,
1011					  gs_usb_receive_bulk_callback, parent);
1012			urb->transfer_flags |= URB_FREE_BUFFER;
1013
1014			usb_anchor_urb(urb, &parent->rx_submitted);
1015
1016			rc = usb_submit_urb(urb, GFP_KERNEL);
1017			if (rc) {
1018				if (rc == -ENODEV)
1019					netif_device_detach(dev->netdev);
1020
1021				netdev_err(netdev,
1022					   "usb_submit_urb() failed, error %pe\n",
1023					   ERR_PTR(rc));
1024
1025				goto out_usb_unanchor_urb;
1026			}
1027
1028			/* Drop reference,
1029			 * USB core will take care of freeing it
1030			 */
1031			usb_free_urb(urb);
1032		}
1033	}
1034
1035	/* flags */
1036	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
1037		flags |= GS_CAN_MODE_LOOP_BACK;
1038
1039	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
1040		flags |= GS_CAN_MODE_LISTEN_ONLY;
1041
1042	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1043		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
1044
1045	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
1046		flags |= GS_CAN_MODE_ONE_SHOT;
1047
1048	if (ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
1049		flags |= GS_CAN_MODE_BERR_REPORTING;
1050
1051	if (ctrlmode & CAN_CTRLMODE_FD)
1052		flags |= GS_CAN_MODE_FD;
1053
1054	/* if hardware supports timestamps, enable it */
1055	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1056		flags |= GS_CAN_MODE_HW_TIMESTAMP;
1057
1058	rc = gs_usb_set_bittiming(dev);
1059	if (rc) {
1060		netdev_err(netdev, "failed to set bittiming: %pe\n", ERR_PTR(rc));
1061		goto out_usb_kill_anchored_urbs;
1062	}
1063
1064	if (ctrlmode & CAN_CTRLMODE_FD) {
1065		rc = gs_usb_set_data_bittiming(dev);
1066		if (rc) {
1067			netdev_err(netdev, "failed to set data bittiming: %pe\n", ERR_PTR(rc));
1068			goto out_usb_kill_anchored_urbs;
1069		}
1070	}
1071
1072	/* finally start device */
1073	dev->can.state = CAN_STATE_ERROR_ACTIVE;
1074	dm.flags = cpu_to_le32(flags);
1075	rc = usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
1076				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1077				  dev->channel, 0, &dm, sizeof(dm), 1000,
1078				  GFP_KERNEL);
1079	if (rc) {
1080		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
1081		dev->can.state = CAN_STATE_STOPPED;
1082
1083		goto out_usb_kill_anchored_urbs;
1084	}
1085
1086	parent->active_channels++;
1087	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
1088		netif_start_queue(netdev);
1089
1090	return 0;
1091
1092out_usb_unanchor_urb:
1093	usb_unanchor_urb(urb);
1094out_usb_free_urb:
1095	usb_free_urb(urb);
1096out_usb_kill_anchored_urbs:
1097	if (!parent->active_channels) {
1098		usb_kill_anchored_urbs(&parent->rx_submitted);
1099
1100		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1101			gs_usb_timestamp_stop(parent);
1102	}
1103
1104	can_rx_offload_disable(&dev->offload);
1105	close_candev(netdev);
1106
1107	return rc;
1108}
1109
1110static int gs_usb_get_state(const struct net_device *netdev,
1111			    struct can_berr_counter *bec,
1112			    enum can_state *state)
1113{
1114	struct gs_can *dev = netdev_priv(netdev);
1115	struct gs_device_state ds;
1116	int rc;
1117
1118	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_STATE,
1119				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1120				  dev->channel, 0,
1121				  &ds, sizeof(ds),
1122				  USB_CTRL_GET_TIMEOUT,
1123				  GFP_KERNEL);
1124	if (rc)
1125		return rc;
1126
1127	if (le32_to_cpu(ds.state) >= CAN_STATE_MAX)
1128		return -EOPNOTSUPP;
1129
1130	*state = le32_to_cpu(ds.state);
1131	bec->txerr = le32_to_cpu(ds.txerr);
1132	bec->rxerr = le32_to_cpu(ds.rxerr);
1133
1134	return 0;
1135}
1136
1137static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
1138				       struct can_berr_counter *bec)
1139{
1140	enum can_state state;
1141
1142	return gs_usb_get_state(netdev, bec, &state);
1143}
1144
1145static int gs_can_close(struct net_device *netdev)
1146{
1147	int rc;
1148	struct gs_can *dev = netdev_priv(netdev);
1149	struct gs_usb *parent = dev->parent;
1150
1151	netif_stop_queue(netdev);
1152
1153	/* Stop polling */
1154	parent->active_channels--;
1155	if (!parent->active_channels) {
1156		usb_kill_anchored_urbs(&parent->rx_submitted);
1157
1158		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1159			gs_usb_timestamp_stop(parent);
1160	}
1161
1162	/* Stop sending URBs */
1163	usb_kill_anchored_urbs(&dev->tx_submitted);
1164	atomic_set(&dev->active_tx_urbs, 0);
1165
1166	dev->can.state = CAN_STATE_STOPPED;
1167
1168	/* reset the device */
1169	gs_cmd_reset(dev);
1170
1171	/* reset tx contexts */
1172	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1173		dev->tx_context[rc].dev = dev;
1174		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1175	}
1176
1177	can_rx_offload_disable(&dev->offload);
1178
1179	/* close the netdev */
1180	close_candev(netdev);
1181
1182	return 0;
1183}
1184
1185static int gs_can_hwtstamp_get(struct net_device *netdev,
1186			       struct kernel_hwtstamp_config *cfg)
1187{
1188	const struct gs_can *dev = netdev_priv(netdev);
1189
1190	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1191		return can_hwtstamp_get(netdev, cfg);
1192
1193	return -EOPNOTSUPP;
1194}
1195
1196static int gs_can_hwtstamp_set(struct net_device *netdev,
1197			       struct kernel_hwtstamp_config *cfg,
1198			       struct netlink_ext_ack *extack)
1199{
1200	const struct gs_can *dev = netdev_priv(netdev);
1201
1202	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1203		return can_hwtstamp_set(netdev, cfg, extack);
1204
1205	return -EOPNOTSUPP;
1206}
1207
1208static const struct net_device_ops gs_usb_netdev_ops = {
1209	.ndo_open = gs_can_open,
1210	.ndo_stop = gs_can_close,
1211	.ndo_start_xmit = gs_can_start_xmit,
1212	.ndo_hwtstamp_get = gs_can_hwtstamp_get,
1213	.ndo_hwtstamp_set = gs_can_hwtstamp_set,
1214};
1215
1216static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
1217{
1218	struct gs_can *dev = netdev_priv(netdev);
1219	struct gs_identify_mode imode;
1220
1221	if (do_identify)
1222		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
1223	else
1224		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
1225
1226	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_IDENTIFY,
1227				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1228				    dev->channel, 0, &imode, sizeof(imode), 100,
1229				    GFP_KERNEL);
1230}
1231
1232/* blink LED's for finding the this interface */
1233static int gs_usb_set_phys_id(struct net_device *netdev,
1234			      enum ethtool_phys_id_state state)
1235{
1236	const struct gs_can *dev = netdev_priv(netdev);
1237	int rc = 0;
1238
1239	if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
1240		return -EOPNOTSUPP;
1241
1242	switch (state) {
1243	case ETHTOOL_ID_ACTIVE:
1244		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
1245		break;
1246	case ETHTOOL_ID_INACTIVE:
1247		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
1248		break;
1249	default:
1250		break;
1251	}
1252
1253	return rc;
1254}
1255
1256static int gs_usb_get_ts_info(struct net_device *netdev,
1257			      struct kernel_ethtool_ts_info *info)
1258{
1259	struct gs_can *dev = netdev_priv(netdev);
1260
1261	/* report if device supports HW timestamps */
1262	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1263		return can_ethtool_op_get_ts_info_hwts(netdev, info);
1264
1265	return ethtool_op_get_ts_info(netdev, info);
1266}
1267
1268static const struct ethtool_ops gs_usb_ethtool_ops = {
1269	.set_phys_id = gs_usb_set_phys_id,
1270	.get_ts_info = gs_usb_get_ts_info,
1271};
1272
1273static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
1274{
1275	struct gs_can *dev = netdev_priv(netdev);
1276	struct gs_device_termination_state term_state;
1277	int rc;
1278
1279	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_TERMINATION,
1280				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1281				  dev->channel, 0,
1282				  &term_state, sizeof(term_state), 1000,
1283				  GFP_KERNEL);
1284	if (rc)
1285		return rc;
1286
1287	if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
1288		*term = GS_USB_TERMINATION_ENABLED;
1289	else
1290		*term = GS_USB_TERMINATION_DISABLED;
1291
1292	return 0;
1293}
1294
1295static int gs_usb_set_termination(struct net_device *netdev, u16 term)
1296{
1297	struct gs_can *dev = netdev_priv(netdev);
1298	struct gs_device_termination_state term_state;
1299
1300	if (term == GS_USB_TERMINATION_ENABLED)
1301		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
1302	else
1303		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
1304
1305	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_SET_TERMINATION,
1306				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1307				    dev->channel, 0,
1308				    &term_state, sizeof(term_state), 1000,
1309				    GFP_KERNEL);
1310}
1311
1312static const u16 gs_usb_termination_const[] = {
1313	GS_USB_TERMINATION_DISABLED,
1314	GS_USB_TERMINATION_ENABLED
1315};
1316
1317static struct gs_can *gs_make_candev(unsigned int channel,
1318				     struct usb_interface *intf,
1319				     struct gs_device_config *dconf)
1320{
1321	struct gs_can *dev;
1322	struct net_device *netdev;
1323	int rc;
1324	struct gs_device_bt_const_extended bt_const_extended;
1325	struct gs_device_bt_const bt_const;
1326	u32 feature;
1327
1328	/* fetch bit timing constants */
1329	rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1330				  GS_USB_BREQ_BT_CONST,
1331				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1332				  channel, 0, &bt_const, sizeof(bt_const), 1000,
1333				  GFP_KERNEL);
1334
1335	if (rc) {
1336		dev_err(&intf->dev,
1337			"Couldn't get bit timing const for channel %d (%pe)\n",
1338			channel, ERR_PTR(rc));
1339		return ERR_PTR(rc);
1340	}
1341
1342	/* create netdev */
1343	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
1344	if (!netdev) {
1345		dev_err(&intf->dev, "Couldn't allocate candev\n");
1346		return ERR_PTR(-ENOMEM);
1347	}
1348
1349	dev = netdev_priv(netdev);
1350
1351	netdev->netdev_ops = &gs_usb_netdev_ops;
1352	netdev->ethtool_ops = &gs_usb_ethtool_ops;
1353
1354	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
1355	netdev->dev_id = channel;
1356	netdev->dev_port = channel;
1357
1358	/* dev setup */
1359	strcpy(dev->bt_const.name, KBUILD_MODNAME);
1360	dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
1361	dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
1362	dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
1363	dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
1364	dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
1365	dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
1366	dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
1367	dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
1368
1369	dev->udev = interface_to_usbdev(intf);
1370	dev->netdev = netdev;
1371	dev->channel = channel;
1372
1373	init_usb_anchor(&dev->tx_submitted);
1374	atomic_set(&dev->active_tx_urbs, 0);
1375	spin_lock_init(&dev->tx_ctx_lock);
1376	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1377		dev->tx_context[rc].dev = dev;
1378		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1379	}
1380
1381	/* can setup */
1382	dev->can.state = CAN_STATE_STOPPED;
1383	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
1384	dev->can.bittiming_const = &dev->bt_const;
1385
1386	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1387
1388	feature = le32_to_cpu(bt_const.feature);
1389	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1390	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1391		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1392
1393	if (feature & GS_CAN_FEATURE_LOOP_BACK)
1394		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1395
1396	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1397		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1398
1399	if (feature & GS_CAN_FEATURE_ONE_SHOT)
1400		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1401
1402	if (feature & GS_CAN_FEATURE_FD) {
1403		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1404		/* The data bit timing will be overwritten, if
1405		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
1406		 */
1407		dev->can.fd.data_bittiming_const = &dev->bt_const;
1408	}
1409
1410	if (feature & GS_CAN_FEATURE_TERMINATION) {
1411		rc = gs_usb_get_termination(netdev, &dev->can.termination);
1412		if (rc) {
1413			dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
1414
1415			dev_info(&intf->dev,
1416				 "Disabling termination support for channel %d (%pe)\n",
1417				 channel, ERR_PTR(rc));
1418		} else {
1419			dev->can.termination_const = gs_usb_termination_const;
1420			dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
1421			dev->can.do_set_termination = gs_usb_set_termination;
1422		}
1423	}
1424
1425	if (feature & GS_CAN_FEATURE_BERR_REPORTING)
1426		dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
1427
1428	if (feature & GS_CAN_FEATURE_GET_STATE)
1429		dev->can.do_get_berr_counter = gs_usb_can_get_berr_counter;
1430
1431	/* The CANtact Pro from LinkLayer Labs is based on the
1432	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
1433	 * erratum. However, the current firmware (version 2) doesn't
1434	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1435	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1436	 * this issue.
1437	 *
1438	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1439	 * CANtact Pro firmware uses a request value, which is already
1440	 * used by the candleLight firmware for a different purpose
1441	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
1442	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1443	 * issue.
1444	 */
1445	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
1446	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
1447	    dev->udev->manufacturer && dev->udev->product &&
1448	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1449	    !strcmp(dev->udev->product, "CANtact Pro") &&
1450	    (le32_to_cpu(dconf->sw_version) <= 2))
1451		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1452			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1453
1454	/* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
1455	if (!(le32_to_cpu(dconf->sw_version) > 1 &&
1456	      feature & GS_CAN_FEATURE_IDENTIFY))
1457		dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
1458
1459	/* fetch extended bit timing constants if device has feature
1460	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1461	 */
1462	if (feature & GS_CAN_FEATURE_FD &&
1463	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1464		rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1465					  GS_USB_BREQ_BT_CONST_EXT,
1466					  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1467					  channel, 0, &bt_const_extended,
1468					  sizeof(bt_const_extended),
1469					  1000, GFP_KERNEL);
1470		if (rc) {
1471			dev_err(&intf->dev,
1472				"Couldn't get extended bit timing const for channel %d (%pe)\n",
1473				channel, ERR_PTR(rc));
1474			goto out_free_candev;
1475		}
1476
1477		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1478		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
1479		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
1480		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
1481		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
1482		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
1483		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
1484		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
1485		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
1486
1487		dev->can.fd.data_bittiming_const = &dev->data_bt_const;
1488	}
1489
1490	can_rx_offload_add_manual(netdev, &dev->offload, GS_NAPI_WEIGHT);
1491	SET_NETDEV_DEV(netdev, &intf->dev);
1492
1493	rc = register_candev(dev->netdev);
1494	if (rc) {
1495		dev_err(&intf->dev,
1496			"Couldn't register candev for channel %d (%pe)\n",
1497			channel, ERR_PTR(rc));
1498		goto out_can_rx_offload_del;
1499	}
1500
1501	return dev;
1502
1503out_can_rx_offload_del:
1504	can_rx_offload_del(&dev->offload);
1505out_free_candev:
1506	free_candev(dev->netdev);
1507	return ERR_PTR(rc);
1508}
1509
1510static void gs_destroy_candev(struct gs_can *dev)
1511{
1512	unregister_candev(dev->netdev);
1513	can_rx_offload_del(&dev->offload);
1514	free_candev(dev->netdev);
1515}
1516
1517static int gs_usb_probe(struct usb_interface *intf,
1518			const struct usb_device_id *id)
1519{
1520	struct usb_device *udev = interface_to_usbdev(intf);
1521	struct usb_endpoint_descriptor *ep_in, *ep_out;
1522	struct gs_host_frame *hf;
1523	struct gs_usb *parent;
1524	struct gs_host_config hconf = {
1525		.byte_order = cpu_to_le32(0x0000beef),
1526	};
1527	struct gs_device_config dconf;
1528	unsigned int icount, i;
1529	int rc;
1530
1531	rc = usb_find_common_endpoints(intf->cur_altsetting,
1532				       &ep_in, &ep_out, NULL, NULL);
1533	if (rc) {
1534		dev_err(&intf->dev, "Required endpoints not found\n");
1535		return rc;
1536	}
1537
1538	/* send host config */
1539	rc = usb_control_msg_send(udev, 0,
1540				  GS_USB_BREQ_HOST_FORMAT,
1541				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1542				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1543				  &hconf, sizeof(hconf), 1000,
1544				  GFP_KERNEL);
1545	if (rc) {
1546		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1547		return rc;
1548	}
1549
1550	/* read device config */
1551	rc = usb_control_msg_recv(udev, 0,
1552				  GS_USB_BREQ_DEVICE_CONFIG,
1553				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1554				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1555				  &dconf, sizeof(dconf), 1000,
1556				  GFP_KERNEL);
1557	if (rc) {
1558		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1559			rc);
1560		return rc;
1561	}
1562
1563	icount = dconf.icount + 1;
1564	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1565
1566	if (icount > type_max(parent->channel_cnt)) {
1567		dev_err(&intf->dev,
1568			"Driver cannot handle more that %u CAN interfaces\n",
1569			type_max(parent->channel_cnt));
1570		return -EINVAL;
1571	}
1572
1573	parent = kzalloc(struct_size(parent, canch, icount), GFP_KERNEL);
1574	if (!parent)
1575		return -ENOMEM;
1576
1577	parent->channel_cnt = icount;
1578
1579	init_usb_anchor(&parent->rx_submitted);
1580
1581	usb_set_intfdata(intf, parent);
1582	parent->udev = udev;
1583
1584	/* store the detected endpoints */
1585	parent->pipe_in = usb_rcvbulkpipe(parent->udev, ep_in->bEndpointAddress);
1586	parent->pipe_out = usb_sndbulkpipe(parent->udev, ep_out->bEndpointAddress);
1587
1588	for (i = 0; i < icount; i++) {
1589		unsigned int hf_size_rx = 0;
1590
1591		parent->canch[i] = gs_make_candev(i, intf, &dconf);
1592		if (IS_ERR_OR_NULL(parent->canch[i])) {
1593			/* save error code to return later */
1594			rc = PTR_ERR(parent->canch[i]);
1595
1596			/* on failure destroy previously created candevs */
1597			icount = i;
1598			for (i = 0; i < icount; i++)
1599				gs_destroy_candev(parent->canch[i]);
1600
1601			usb_kill_anchored_urbs(&parent->rx_submitted);
1602			kfree(parent);
1603			return rc;
1604		}
1605		parent->canch[i]->parent = parent;
1606
1607		/* set RX packet size based on FD and if hardware
1608		 * timestamps are supported.
1609		 */
1610		if (parent->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1611			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1612				hf_size_rx = struct_size(hf, canfd_ts, 1);
1613			else
1614				hf_size_rx = struct_size(hf, canfd, 1);
1615		} else {
1616			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1617				hf_size_rx = struct_size(hf, classic_can_ts, 1);
1618			else
1619				hf_size_rx = struct_size(hf, classic_can, 1);
1620		}
1621		parent->hf_size_rx = max(parent->hf_size_rx, hf_size_rx);
1622	}
1623
1624	return 0;
1625}
1626
1627static void gs_usb_disconnect(struct usb_interface *intf)
1628{
1629	struct gs_usb *parent = usb_get_intfdata(intf);
1630	unsigned int i;
1631
1632	usb_set_intfdata(intf, NULL);
1633
1634	if (!parent) {
1635		dev_err(&intf->dev, "Disconnect (nodata)\n");
1636		return;
1637	}
1638
1639	for (i = 0; i < parent->channel_cnt; i++)
1640		if (parent->canch[i])
1641			gs_destroy_candev(parent->canch[i]);
1642
1643	kfree(parent);
1644}
1645
1646static const struct usb_device_id gs_usb_table[] = {
1647	{ USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
1648				      USB_GS_USB_1_PRODUCT_ID, 0) },
1649	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1650				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1651	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1652				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1653	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1654				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1655	{ USB_DEVICE_INTERFACE_NUMBER(USB_XYLANTA_SAINT3_VENDOR_ID,
1656				      USB_XYLANTA_SAINT3_PRODUCT_ID, 0) },
1657	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANNECTIVITY_VENDOR_ID,
1658				      USB_CANNECTIVITY_PRODUCT_ID, 0) },
1659	{} /* Terminating entry */
1660};
1661
1662MODULE_DEVICE_TABLE(usb, gs_usb_table);
1663
1664static struct usb_driver gs_usb_driver = {
1665	.name = KBUILD_MODNAME,
1666	.probe = gs_usb_probe,
1667	.disconnect = gs_usb_disconnect,
1668	.id_table = gs_usb_table,
1669};
1670
1671module_usb_driver(gs_usb_driver);
1672
1673MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1674MODULE_DESCRIPTION(
1675"Socket CAN device driver for Geschwister Schneider Technologie-, "
1676"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1677"and bytewerk.org candleLight USB CAN interfaces.");
1678MODULE_LICENSE("GPL v2");