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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * CAN driver for esd CAN-USB/2 and CAN-USB/Micro
   4 *
   5 * Copyright (C) 2010-2012 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
   6 */
   7#include <linux/signal.h>
   8#include <linux/slab.h>
   9#include <linux/module.h>
  10#include <linux/netdevice.h>
  11#include <linux/usb.h>
  12
  13#include <linux/can.h>
  14#include <linux/can/dev.h>
  15#include <linux/can/error.h>
  16
  17MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
  18MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 and CAN-USB/Micro interfaces");
  19MODULE_LICENSE("GPL v2");
  20
  21/* Define these values to match your devices */
  22#define USB_ESDGMBH_VENDOR_ID	0x0ab4
  23#define USB_CANUSB2_PRODUCT_ID	0x0010
  24#define USB_CANUSBM_PRODUCT_ID	0x0011
  25
  26#define ESD_USB2_CAN_CLOCK	60000000
  27#define ESD_USBM_CAN_CLOCK	36000000
  28#define ESD_USB2_MAX_NETS	2
  29
  30/* USB2 commands */
  31#define CMD_VERSION		1 /* also used for VERSION_REPLY */
  32#define CMD_CAN_RX		2 /* device to host only */
  33#define CMD_CAN_TX		3 /* also used for TX_DONE */
  34#define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
  35#define CMD_TS			5 /* also used for TS_REPLY */
  36#define CMD_IDADD		6 /* also used for IDADD_REPLY */
  37
  38/* esd CAN message flags - dlc field */
  39#define ESD_RTR			0x10
  40
  41/* esd CAN message flags - id field */
  42#define ESD_EXTID		0x20000000
  43#define ESD_EVENT		0x40000000
  44#define ESD_IDMASK		0x1fffffff
  45
  46/* esd CAN event ids used by this driver */
  47#define ESD_EV_CAN_ERROR_EXT	2
  48
  49/* baudrate message flags */
  50#define ESD_USB2_UBR		0x80000000
  51#define ESD_USB2_LOM		0x40000000
  52#define ESD_USB2_NO_BAUDRATE	0x7fffffff
  53#define ESD_USB2_TSEG1_MIN	1
  54#define ESD_USB2_TSEG1_MAX	16
  55#define ESD_USB2_TSEG1_SHIFT	16
  56#define ESD_USB2_TSEG2_MIN	1
  57#define ESD_USB2_TSEG2_MAX	8
  58#define ESD_USB2_TSEG2_SHIFT	20
  59#define ESD_USB2_SJW_MAX	4
  60#define ESD_USB2_SJW_SHIFT	14
  61#define ESD_USBM_SJW_SHIFT	24
  62#define ESD_USB2_BRP_MIN	1
  63#define ESD_USB2_BRP_MAX	1024
  64#define ESD_USB2_BRP_INC	1
  65#define ESD_USB2_3_SAMPLES	0x00800000
  66
  67/* esd IDADD message */
  68#define ESD_ID_ENABLE		0x80
  69#define ESD_MAX_ID_SEGMENT	64
  70
  71/* SJA1000 ECC register (emulated by usb2 firmware) */
  72#define SJA1000_ECC_SEG		0x1F
  73#define SJA1000_ECC_DIR		0x20
  74#define SJA1000_ECC_ERR		0x06
  75#define SJA1000_ECC_BIT		0x00
  76#define SJA1000_ECC_FORM	0x40
  77#define SJA1000_ECC_STUFF	0x80
  78#define SJA1000_ECC_MASK	0xc0
  79
  80/* esd bus state event codes */
  81#define ESD_BUSSTATE_MASK	0xc0
  82#define ESD_BUSSTATE_WARN	0x40
  83#define ESD_BUSSTATE_ERRPASSIVE	0x80
  84#define ESD_BUSSTATE_BUSOFF	0xc0
  85
  86#define RX_BUFFER_SIZE		1024
  87#define MAX_RX_URBS		4
  88#define MAX_TX_URBS		16 /* must be power of 2 */
  89
  90struct header_msg {
  91	u8 len; /* len is always the total message length in 32bit words */
  92	u8 cmd;
  93	u8 rsvd[2];
  94};
  95
  96struct version_msg {
  97	u8 len;
  98	u8 cmd;
  99	u8 rsvd;
 100	u8 flags;
 101	__le32 drv_version;
 102};
 103
 104struct version_reply_msg {
 105	u8 len;
 106	u8 cmd;
 107	u8 nets;
 108	u8 features;
 109	__le32 version;
 110	u8 name[16];
 111	__le32 rsvd;
 112	__le32 ts;
 113};
 114
 115struct rx_msg {
 116	u8 len;
 117	u8 cmd;
 118	u8 net;
 119	u8 dlc;
 120	__le32 ts;
 121	__le32 id; /* upper 3 bits contain flags */
 122	u8 data[8];
 123};
 124
 125struct tx_msg {
 126	u8 len;
 127	u8 cmd;
 128	u8 net;
 129	u8 dlc;
 130	u32 hnd;	/* opaque handle, not used by device */
 131	__le32 id; /* upper 3 bits contain flags */
 132	u8 data[8];
 133};
 134
 135struct tx_done_msg {
 136	u8 len;
 137	u8 cmd;
 138	u8 net;
 139	u8 status;
 140	u32 hnd;	/* opaque handle, not used by device */
 141	__le32 ts;
 142};
 143
 144struct id_filter_msg {
 145	u8 len;
 146	u8 cmd;
 147	u8 net;
 148	u8 option;
 149	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
 150};
 151
 152struct set_baudrate_msg {
 153	u8 len;
 154	u8 cmd;
 155	u8 net;
 156	u8 rsvd;
 157	__le32 baud;
 158};
 159
 160/* Main message type used between library and application */
 161struct __attribute__ ((packed)) esd_usb2_msg {
 162	union {
 163		struct header_msg hdr;
 164		struct version_msg version;
 165		struct version_reply_msg version_reply;
 166		struct rx_msg rx;
 167		struct tx_msg tx;
 168		struct tx_done_msg txdone;
 169		struct set_baudrate_msg setbaud;
 170		struct id_filter_msg filter;
 171	} msg;
 172};
 173
 174static struct usb_device_id esd_usb2_table[] = {
 175	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
 176	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSBM_PRODUCT_ID)},
 177	{}
 178};
 179MODULE_DEVICE_TABLE(usb, esd_usb2_table);
 180
 181struct esd_usb2_net_priv;
 182
 183struct esd_tx_urb_context {
 184	struct esd_usb2_net_priv *priv;
 185	u32 echo_index;
 186	int len;	/* CAN payload length */
 187};
 188
 189struct esd_usb2 {
 190	struct usb_device *udev;
 191	struct esd_usb2_net_priv *nets[ESD_USB2_MAX_NETS];
 192
 193	struct usb_anchor rx_submitted;
 194
 195	int net_count;
 196	u32 version;
 197	int rxinitdone;
 198	void *rxbuf[MAX_RX_URBS];
 199	dma_addr_t rxbuf_dma[MAX_RX_URBS];
 200};
 201
 202struct esd_usb2_net_priv {
 203	struct can_priv can; /* must be the first member */
 204
 205	atomic_t active_tx_jobs;
 206	struct usb_anchor tx_submitted;
 207	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
 208
 209	struct esd_usb2 *usb2;
 210	struct net_device *netdev;
 211	int index;
 212	u8 old_state;
 213	struct can_berr_counter bec;
 214};
 215
 216static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
 217			      struct esd_usb2_msg *msg)
 218{
 219	struct net_device_stats *stats = &priv->netdev->stats;
 220	struct can_frame *cf;
 221	struct sk_buff *skb;
 222	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
 223
 224	if (id == ESD_EV_CAN_ERROR_EXT) {
 225		u8 state = msg->msg.rx.data[0];
 226		u8 ecc = msg->msg.rx.data[1];
 227		u8 rxerr = msg->msg.rx.data[2];
 228		u8 txerr = msg->msg.rx.data[3];
 229
 230		skb = alloc_can_err_skb(priv->netdev, &cf);
 231		if (skb == NULL) {
 232			stats->rx_dropped++;
 233			return;
 234		}
 235
 236		if (state != priv->old_state) {
 237			priv->old_state = state;
 238
 239			switch (state & ESD_BUSSTATE_MASK) {
 240			case ESD_BUSSTATE_BUSOFF:
 241				priv->can.state = CAN_STATE_BUS_OFF;
 242				cf->can_id |= CAN_ERR_BUSOFF;
 243				priv->can.can_stats.bus_off++;
 244				can_bus_off(priv->netdev);
 245				break;
 246			case ESD_BUSSTATE_WARN:
 247				priv->can.state = CAN_STATE_ERROR_WARNING;
 248				priv->can.can_stats.error_warning++;
 249				break;
 250			case ESD_BUSSTATE_ERRPASSIVE:
 251				priv->can.state = CAN_STATE_ERROR_PASSIVE;
 252				priv->can.can_stats.error_passive++;
 253				break;
 254			default:
 255				priv->can.state = CAN_STATE_ERROR_ACTIVE;
 256				break;
 257			}
 258		} else {
 259			priv->can.can_stats.bus_error++;
 260			stats->rx_errors++;
 261
 262			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 263
 264			switch (ecc & SJA1000_ECC_MASK) {
 265			case SJA1000_ECC_BIT:
 266				cf->data[2] |= CAN_ERR_PROT_BIT;
 267				break;
 268			case SJA1000_ECC_FORM:
 269				cf->data[2] |= CAN_ERR_PROT_FORM;
 270				break;
 271			case SJA1000_ECC_STUFF:
 272				cf->data[2] |= CAN_ERR_PROT_STUFF;
 273				break;
 274			default:
 275				cf->data[3] = ecc & SJA1000_ECC_SEG;
 276				break;
 277			}
 278
 279			/* Error occurred during transmission? */
 280			if (!(ecc & SJA1000_ECC_DIR))
 281				cf->data[2] |= CAN_ERR_PROT_TX;
 282
 283			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
 284			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
 285				cf->data[1] = (txerr > rxerr) ?
 286					CAN_ERR_CRTL_TX_PASSIVE :
 287					CAN_ERR_CRTL_RX_PASSIVE;
 288			}
 289			cf->data[6] = txerr;
 290			cf->data[7] = rxerr;
 291		}
 292
 293		priv->bec.txerr = txerr;
 294		priv->bec.rxerr = rxerr;
 295
 296		stats->rx_packets++;
 297		stats->rx_bytes += cf->len;
 298		netif_rx(skb);
 299	}
 300}
 301
 302static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
 303				struct esd_usb2_msg *msg)
 304{
 305	struct net_device_stats *stats = &priv->netdev->stats;
 306	struct can_frame *cf;
 307	struct sk_buff *skb;
 308	int i;
 309	u32 id;
 310
 311	if (!netif_device_present(priv->netdev))
 312		return;
 313
 314	id = le32_to_cpu(msg->msg.rx.id);
 315
 316	if (id & ESD_EVENT) {
 317		esd_usb2_rx_event(priv, msg);
 318	} else {
 319		skb = alloc_can_skb(priv->netdev, &cf);
 320		if (skb == NULL) {
 321			stats->rx_dropped++;
 322			return;
 323		}
 324
 325		cf->can_id = id & ESD_IDMASK;
 326		can_frame_set_cc_len(cf, msg->msg.rx.dlc & ~ESD_RTR,
 327				     priv->can.ctrlmode);
 328
 329		if (id & ESD_EXTID)
 330			cf->can_id |= CAN_EFF_FLAG;
 331
 332		if (msg->msg.rx.dlc & ESD_RTR) {
 333			cf->can_id |= CAN_RTR_FLAG;
 334		} else {
 335			for (i = 0; i < cf->len; i++)
 336				cf->data[i] = msg->msg.rx.data[i];
 337		}
 338
 339		stats->rx_packets++;
 340		stats->rx_bytes += cf->len;
 341		netif_rx(skb);
 342	}
 343
 344	return;
 345}
 346
 347static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
 348				 struct esd_usb2_msg *msg)
 349{
 350	struct net_device_stats *stats = &priv->netdev->stats;
 351	struct net_device *netdev = priv->netdev;
 352	struct esd_tx_urb_context *context;
 353
 354	if (!netif_device_present(netdev))
 355		return;
 356
 357	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
 358
 359	if (!msg->msg.txdone.status) {
 360		stats->tx_packets++;
 361		stats->tx_bytes += context->len;
 362		can_get_echo_skb(netdev, context->echo_index, NULL);
 363	} else {
 364		stats->tx_errors++;
 365		can_free_echo_skb(netdev, context->echo_index, NULL);
 366	}
 367
 368	/* Release context */
 369	context->echo_index = MAX_TX_URBS;
 370	atomic_dec(&priv->active_tx_jobs);
 371
 372	netif_wake_queue(netdev);
 373}
 374
 375static void esd_usb2_read_bulk_callback(struct urb *urb)
 376{
 377	struct esd_usb2 *dev = urb->context;
 378	int retval;
 379	int pos = 0;
 380	int i;
 381
 382	switch (urb->status) {
 383	case 0: /* success */
 384		break;
 385
 386	case -ENOENT:
 387	case -EPIPE:
 388	case -EPROTO:
 389	case -ESHUTDOWN:
 390		return;
 391
 392	default:
 393		dev_info(dev->udev->dev.parent,
 394			 "Rx URB aborted (%d)\n", urb->status);
 395		goto resubmit_urb;
 396	}
 397
 398	while (pos < urb->actual_length) {
 399		struct esd_usb2_msg *msg;
 400
 401		msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
 402
 403		switch (msg->msg.hdr.cmd) {
 404		case CMD_CAN_RX:
 405			if (msg->msg.rx.net >= dev->net_count) {
 406				dev_err(dev->udev->dev.parent, "format error\n");
 407				break;
 408			}
 409
 410			esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
 411			break;
 412
 413		case CMD_CAN_TX:
 414			if (msg->msg.txdone.net >= dev->net_count) {
 415				dev_err(dev->udev->dev.parent, "format error\n");
 416				break;
 417			}
 418
 419			esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
 420					     msg);
 421			break;
 422		}
 423
 424		pos += msg->msg.hdr.len << 2;
 425
 426		if (pos > urb->actual_length) {
 427			dev_err(dev->udev->dev.parent, "format error\n");
 428			break;
 429		}
 430	}
 431
 432resubmit_urb:
 433	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
 434			  urb->transfer_buffer, RX_BUFFER_SIZE,
 435			  esd_usb2_read_bulk_callback, dev);
 436
 437	retval = usb_submit_urb(urb, GFP_ATOMIC);
 438	if (retval == -ENODEV) {
 439		for (i = 0; i < dev->net_count; i++) {
 440			if (dev->nets[i])
 441				netif_device_detach(dev->nets[i]->netdev);
 442		}
 443	} else if (retval) {
 444		dev_err(dev->udev->dev.parent,
 445			"failed resubmitting read bulk urb: %d\n", retval);
 446	}
 447
 448	return;
 449}
 450
 451/*
 452 * callback for bulk IN urb
 453 */
 454static void esd_usb2_write_bulk_callback(struct urb *urb)
 455{
 456	struct esd_tx_urb_context *context = urb->context;
 457	struct esd_usb2_net_priv *priv;
 458	struct net_device *netdev;
 459	size_t size = sizeof(struct esd_usb2_msg);
 460
 461	WARN_ON(!context);
 462
 463	priv = context->priv;
 464	netdev = priv->netdev;
 465
 466	/* free up our allocated buffer */
 467	usb_free_coherent(urb->dev, size,
 468			  urb->transfer_buffer, urb->transfer_dma);
 469
 470	if (!netif_device_present(netdev))
 471		return;
 472
 473	if (urb->status)
 474		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 475
 476	netif_trans_update(netdev);
 477}
 478
 479static ssize_t show_firmware(struct device *d,
 480			     struct device_attribute *attr, char *buf)
 481{
 482	struct usb_interface *intf = to_usb_interface(d);
 483	struct esd_usb2 *dev = usb_get_intfdata(intf);
 484
 485	return sprintf(buf, "%d.%d.%d\n",
 486		       (dev->version >> 12) & 0xf,
 487		       (dev->version >> 8) & 0xf,
 488		       dev->version & 0xff);
 489}
 490static DEVICE_ATTR(firmware, 0444, show_firmware, NULL);
 491
 492static ssize_t show_hardware(struct device *d,
 493			     struct device_attribute *attr, char *buf)
 494{
 495	struct usb_interface *intf = to_usb_interface(d);
 496	struct esd_usb2 *dev = usb_get_intfdata(intf);
 497
 498	return sprintf(buf, "%d.%d.%d\n",
 499		       (dev->version >> 28) & 0xf,
 500		       (dev->version >> 24) & 0xf,
 501		       (dev->version >> 16) & 0xff);
 502}
 503static DEVICE_ATTR(hardware, 0444, show_hardware, NULL);
 504
 505static ssize_t show_nets(struct device *d,
 506			 struct device_attribute *attr, char *buf)
 507{
 508	struct usb_interface *intf = to_usb_interface(d);
 509	struct esd_usb2 *dev = usb_get_intfdata(intf);
 510
 511	return sprintf(buf, "%d", dev->net_count);
 512}
 513static DEVICE_ATTR(nets, 0444, show_nets, NULL);
 514
 515static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
 516{
 517	int actual_length;
 518
 519	return usb_bulk_msg(dev->udev,
 520			    usb_sndbulkpipe(dev->udev, 2),
 521			    msg,
 522			    msg->msg.hdr.len << 2,
 523			    &actual_length,
 524			    1000);
 525}
 526
 527static int esd_usb2_wait_msg(struct esd_usb2 *dev,
 528			     struct esd_usb2_msg *msg)
 529{
 530	int actual_length;
 531
 532	return usb_bulk_msg(dev->udev,
 533			    usb_rcvbulkpipe(dev->udev, 1),
 534			    msg,
 535			    sizeof(*msg),
 536			    &actual_length,
 537			    1000);
 538}
 539
 540static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
 541{
 542	int i, err = 0;
 543
 544	if (dev->rxinitdone)
 545		return 0;
 546
 547	for (i = 0; i < MAX_RX_URBS; i++) {
 548		struct urb *urb = NULL;
 549		u8 *buf = NULL;
 550		dma_addr_t buf_dma;
 551
 552		/* create a URB, and a buffer for it */
 553		urb = usb_alloc_urb(0, GFP_KERNEL);
 554		if (!urb) {
 555			err = -ENOMEM;
 556			break;
 557		}
 558
 559		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 560					 &buf_dma);
 561		if (!buf) {
 562			dev_warn(dev->udev->dev.parent,
 563				 "No memory left for USB buffer\n");
 564			err = -ENOMEM;
 565			goto freeurb;
 566		}
 567
 568		urb->transfer_dma = buf_dma;
 569
 570		usb_fill_bulk_urb(urb, dev->udev,
 571				  usb_rcvbulkpipe(dev->udev, 1),
 572				  buf, RX_BUFFER_SIZE,
 573				  esd_usb2_read_bulk_callback, dev);
 574		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 575		usb_anchor_urb(urb, &dev->rx_submitted);
 576
 577		err = usb_submit_urb(urb, GFP_KERNEL);
 578		if (err) {
 579			usb_unanchor_urb(urb);
 580			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 581					  urb->transfer_dma);
 582			goto freeurb;
 583		}
 584
 585		dev->rxbuf[i] = buf;
 586		dev->rxbuf_dma[i] = buf_dma;
 587
 588freeurb:
 589		/* Drop reference, USB core will take care of freeing it */
 590		usb_free_urb(urb);
 591		if (err)
 592			break;
 593	}
 594
 595	/* Did we submit any URBs */
 596	if (i == 0) {
 597		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
 598		return err;
 599	}
 600
 601	/* Warn if we've couldn't transmit all the URBs */
 602	if (i < MAX_RX_URBS) {
 603		dev_warn(dev->udev->dev.parent,
 604			 "rx performance may be slow\n");
 605	}
 606
 607	dev->rxinitdone = 1;
 608	return 0;
 609}
 610
 611/*
 612 * Start interface
 613 */
 614static int esd_usb2_start(struct esd_usb2_net_priv *priv)
 615{
 616	struct esd_usb2 *dev = priv->usb2;
 617	struct net_device *netdev = priv->netdev;
 618	struct esd_usb2_msg *msg;
 619	int err, i;
 620
 621	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 622	if (!msg) {
 623		err = -ENOMEM;
 624		goto out;
 625	}
 626
 627	/*
 628	 * Enable all IDs
 629	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
 630	 * Each bit represents one 11 bit CAN identifier. A set bit
 631	 * enables reception of the corresponding CAN identifier. A cleared
 632	 * bit disabled this identifier. An additional bitmask value
 633	 * following the CAN 2.0A bits is used to enable reception of
 634	 * extended CAN frames. Only the LSB of this final mask is checked
 635	 * for the complete 29 bit ID range. The IDADD message also allows
 636	 * filter configuration for an ID subset. In this case you can add
 637	 * the number of the starting bitmask (0..64) to the filter.option
 638	 * field followed by only some bitmasks.
 639	 */
 640	msg->msg.hdr.cmd = CMD_IDADD;
 641	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 642	msg->msg.filter.net = priv->index;
 643	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 644	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
 645		msg->msg.filter.mask[i] = cpu_to_le32(0xffffffff);
 646	/* enable 29bit extended IDs */
 647	msg->msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
 648
 649	err = esd_usb2_send_msg(dev, msg);
 650	if (err)
 651		goto out;
 652
 653	err = esd_usb2_setup_rx_urbs(dev);
 654	if (err)
 655		goto out;
 656
 657	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 658
 659out:
 660	if (err == -ENODEV)
 661		netif_device_detach(netdev);
 662	if (err)
 663		netdev_err(netdev, "couldn't start device: %d\n", err);
 664
 665	kfree(msg);
 666	return err;
 667}
 668
 669static void unlink_all_urbs(struct esd_usb2 *dev)
 670{
 671	struct esd_usb2_net_priv *priv;
 672	int i, j;
 673
 674	usb_kill_anchored_urbs(&dev->rx_submitted);
 675
 676	for (i = 0; i < MAX_RX_URBS; ++i)
 677		usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
 678				  dev->rxbuf[i], dev->rxbuf_dma[i]);
 679
 680	for (i = 0; i < dev->net_count; i++) {
 681		priv = dev->nets[i];
 682		if (priv) {
 683			usb_kill_anchored_urbs(&priv->tx_submitted);
 684			atomic_set(&priv->active_tx_jobs, 0);
 685
 686			for (j = 0; j < MAX_TX_URBS; j++)
 687				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
 688		}
 689	}
 690}
 691
 692static int esd_usb2_open(struct net_device *netdev)
 693{
 694	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 695	int err;
 696
 697	/* common open */
 698	err = open_candev(netdev);
 699	if (err)
 700		return err;
 701
 702	/* finally start device */
 703	err = esd_usb2_start(priv);
 704	if (err) {
 705		netdev_warn(netdev, "couldn't start device: %d\n", err);
 706		close_candev(netdev);
 707		return err;
 708	}
 709
 710	netif_start_queue(netdev);
 711
 712	return 0;
 713}
 714
 715static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
 716				      struct net_device *netdev)
 717{
 718	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 719	struct esd_usb2 *dev = priv->usb2;
 720	struct esd_tx_urb_context *context = NULL;
 721	struct net_device_stats *stats = &netdev->stats;
 722	struct can_frame *cf = (struct can_frame *)skb->data;
 723	struct esd_usb2_msg *msg;
 724	struct urb *urb;
 725	u8 *buf;
 726	int i, err;
 727	int ret = NETDEV_TX_OK;
 728	size_t size = sizeof(struct esd_usb2_msg);
 729
 730	if (can_dropped_invalid_skb(netdev, skb))
 731		return NETDEV_TX_OK;
 732
 733	/* create a URB, and a buffer for it, and copy the data to the URB */
 734	urb = usb_alloc_urb(0, GFP_ATOMIC);
 735	if (!urb) {
 736		stats->tx_dropped++;
 737		dev_kfree_skb(skb);
 738		goto nourbmem;
 739	}
 740
 741	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
 742				 &urb->transfer_dma);
 743	if (!buf) {
 744		netdev_err(netdev, "No memory left for USB buffer\n");
 745		stats->tx_dropped++;
 746		dev_kfree_skb(skb);
 747		goto nobufmem;
 748	}
 749
 750	msg = (struct esd_usb2_msg *)buf;
 751
 752	msg->msg.hdr.len = 3; /* minimal length */
 753	msg->msg.hdr.cmd = CMD_CAN_TX;
 754	msg->msg.tx.net = priv->index;
 755	msg->msg.tx.dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
 756	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
 757
 758	if (cf->can_id & CAN_RTR_FLAG)
 759		msg->msg.tx.dlc |= ESD_RTR;
 760
 761	if (cf->can_id & CAN_EFF_FLAG)
 762		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
 763
 764	for (i = 0; i < cf->len; i++)
 765		msg->msg.tx.data[i] = cf->data[i];
 766
 767	msg->msg.hdr.len += (cf->len + 3) >> 2;
 768
 769	for (i = 0; i < MAX_TX_URBS; i++) {
 770		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 771			context = &priv->tx_contexts[i];
 772			break;
 773		}
 774	}
 775
 776	/*
 777	 * This may never happen.
 778	 */
 779	if (!context) {
 780		netdev_warn(netdev, "couldn't find free context\n");
 781		ret = NETDEV_TX_BUSY;
 782		goto releasebuf;
 783	}
 784
 785	context->priv = priv;
 786	context->echo_index = i;
 787	context->len = cf->len;
 788
 789	/* hnd must not be 0 - MSB is stripped in txdone handling */
 790	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
 791
 792	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 793			  msg->msg.hdr.len << 2,
 794			  esd_usb2_write_bulk_callback, context);
 795
 796	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 797
 798	usb_anchor_urb(urb, &priv->tx_submitted);
 799
 800	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 801
 802	atomic_inc(&priv->active_tx_jobs);
 803
 804	/* Slow down tx path */
 805	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
 806		netif_stop_queue(netdev);
 807
 808	err = usb_submit_urb(urb, GFP_ATOMIC);
 809	if (err) {
 810		can_free_echo_skb(netdev, context->echo_index, NULL);
 811
 812		atomic_dec(&priv->active_tx_jobs);
 813		usb_unanchor_urb(urb);
 814
 815		stats->tx_dropped++;
 816
 817		if (err == -ENODEV)
 818			netif_device_detach(netdev);
 819		else
 820			netdev_warn(netdev, "failed tx_urb %d\n", err);
 821
 822		goto releasebuf;
 823	}
 824
 825	netif_trans_update(netdev);
 826
 827	/*
 828	 * Release our reference to this URB, the USB core will eventually free
 829	 * it entirely.
 830	 */
 831	usb_free_urb(urb);
 832
 833	return NETDEV_TX_OK;
 834
 835releasebuf:
 836	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 837
 838nobufmem:
 839	usb_free_urb(urb);
 840
 841nourbmem:
 842	return ret;
 843}
 844
 845static int esd_usb2_close(struct net_device *netdev)
 846{
 847	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 848	struct esd_usb2_msg *msg;
 849	int i;
 850
 851	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 852	if (!msg)
 853		return -ENOMEM;
 854
 855	/* Disable all IDs (see esd_usb2_start()) */
 856	msg->msg.hdr.cmd = CMD_IDADD;
 857	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 858	msg->msg.filter.net = priv->index;
 859	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 860	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
 861		msg->msg.filter.mask[i] = 0;
 862	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
 863		netdev_err(netdev, "sending idadd message failed\n");
 864
 865	/* set CAN controller to reset mode */
 866	msg->msg.hdr.len = 2;
 867	msg->msg.hdr.cmd = CMD_SETBAUD;
 868	msg->msg.setbaud.net = priv->index;
 869	msg->msg.setbaud.rsvd = 0;
 870	msg->msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
 871	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
 872		netdev_err(netdev, "sending setbaud message failed\n");
 873
 874	priv->can.state = CAN_STATE_STOPPED;
 875
 876	netif_stop_queue(netdev);
 877
 878	close_candev(netdev);
 879
 880	kfree(msg);
 881
 882	return 0;
 883}
 884
 885static const struct net_device_ops esd_usb2_netdev_ops = {
 886	.ndo_open = esd_usb2_open,
 887	.ndo_stop = esd_usb2_close,
 888	.ndo_start_xmit = esd_usb2_start_xmit,
 889	.ndo_change_mtu = can_change_mtu,
 890};
 891
 892static const struct can_bittiming_const esd_usb2_bittiming_const = {
 893	.name = "esd_usb2",
 894	.tseg1_min = ESD_USB2_TSEG1_MIN,
 895	.tseg1_max = ESD_USB2_TSEG1_MAX,
 896	.tseg2_min = ESD_USB2_TSEG2_MIN,
 897	.tseg2_max = ESD_USB2_TSEG2_MAX,
 898	.sjw_max = ESD_USB2_SJW_MAX,
 899	.brp_min = ESD_USB2_BRP_MIN,
 900	.brp_max = ESD_USB2_BRP_MAX,
 901	.brp_inc = ESD_USB2_BRP_INC,
 902};
 903
 904static int esd_usb2_set_bittiming(struct net_device *netdev)
 905{
 906	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 907	struct can_bittiming *bt = &priv->can.bittiming;
 908	struct esd_usb2_msg *msg;
 909	int err;
 910	u32 canbtr;
 911	int sjw_shift;
 912
 913	canbtr = ESD_USB2_UBR;
 914	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 915		canbtr |= ESD_USB2_LOM;
 916
 917	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
 918
 919	if (le16_to_cpu(priv->usb2->udev->descriptor.idProduct) ==
 920	    USB_CANUSBM_PRODUCT_ID)
 921		sjw_shift = ESD_USBM_SJW_SHIFT;
 922	else
 923		sjw_shift = ESD_USB2_SJW_SHIFT;
 924
 925	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
 926		<< sjw_shift;
 927	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
 928		   & (ESD_USB2_TSEG1_MAX - 1))
 929		<< ESD_USB2_TSEG1_SHIFT;
 930	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
 931		<< ESD_USB2_TSEG2_SHIFT;
 932	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 933		canbtr |= ESD_USB2_3_SAMPLES;
 934
 935	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 936	if (!msg)
 937		return -ENOMEM;
 938
 939	msg->msg.hdr.len = 2;
 940	msg->msg.hdr.cmd = CMD_SETBAUD;
 941	msg->msg.setbaud.net = priv->index;
 942	msg->msg.setbaud.rsvd = 0;
 943	msg->msg.setbaud.baud = cpu_to_le32(canbtr);
 944
 945	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
 946
 947	err = esd_usb2_send_msg(priv->usb2, msg);
 948
 949	kfree(msg);
 950	return err;
 951}
 952
 953static int esd_usb2_get_berr_counter(const struct net_device *netdev,
 954				     struct can_berr_counter *bec)
 955{
 956	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 957
 958	bec->txerr = priv->bec.txerr;
 959	bec->rxerr = priv->bec.rxerr;
 960
 961	return 0;
 962}
 963
 964static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
 965{
 966	switch (mode) {
 967	case CAN_MODE_START:
 968		netif_wake_queue(netdev);
 969		break;
 970
 971	default:
 972		return -EOPNOTSUPP;
 973	}
 974
 975	return 0;
 976}
 977
 978static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
 979{
 980	struct esd_usb2 *dev = usb_get_intfdata(intf);
 981	struct net_device *netdev;
 982	struct esd_usb2_net_priv *priv;
 983	int err = 0;
 984	int i;
 985
 986	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
 987	if (!netdev) {
 988		dev_err(&intf->dev, "couldn't alloc candev\n");
 989		err = -ENOMEM;
 990		goto done;
 991	}
 992
 993	priv = netdev_priv(netdev);
 994
 995	init_usb_anchor(&priv->tx_submitted);
 996	atomic_set(&priv->active_tx_jobs, 0);
 997
 998	for (i = 0; i < MAX_TX_URBS; i++)
 999		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
1000
1001	priv->usb2 = dev;
1002	priv->netdev = netdev;
1003	priv->index = index;
1004
1005	priv->can.state = CAN_STATE_STOPPED;
1006	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
1007		CAN_CTRLMODE_CC_LEN8_DLC;
1008
1009	if (le16_to_cpu(dev->udev->descriptor.idProduct) ==
1010	    USB_CANUSBM_PRODUCT_ID)
1011		priv->can.clock.freq = ESD_USBM_CAN_CLOCK;
1012	else {
1013		priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
1014		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1015	}
1016
1017	priv->can.bittiming_const = &esd_usb2_bittiming_const;
1018	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
1019	priv->can.do_set_mode = esd_usb2_set_mode;
1020	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
1021
1022	netdev->flags |= IFF_ECHO; /* we support local echo */
1023
1024	netdev->netdev_ops = &esd_usb2_netdev_ops;
1025
1026	SET_NETDEV_DEV(netdev, &intf->dev);
1027	netdev->dev_id = index;
1028
1029	err = register_candev(netdev);
1030	if (err) {
1031		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
1032		free_candev(netdev);
1033		err = -ENOMEM;
1034		goto done;
1035	}
1036
1037	dev->nets[index] = priv;
1038	netdev_info(netdev, "device %s registered\n", netdev->name);
1039
1040done:
1041	return err;
1042}
1043
1044/*
1045 * probe function for new USB2 devices
1046 *
1047 * check version information and number of available
1048 * CAN interfaces
1049 */
1050static int esd_usb2_probe(struct usb_interface *intf,
1051			 const struct usb_device_id *id)
1052{
1053	struct esd_usb2 *dev;
1054	struct esd_usb2_msg *msg;
1055	int i, err;
1056
1057	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1058	if (!dev) {
1059		err = -ENOMEM;
1060		goto done;
1061	}
1062
1063	dev->udev = interface_to_usbdev(intf);
1064
1065	init_usb_anchor(&dev->rx_submitted);
1066
1067	usb_set_intfdata(intf, dev);
1068
1069	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1070	if (!msg) {
1071		err = -ENOMEM;
1072		goto free_msg;
1073	}
1074
1075	/* query number of CAN interfaces (nets) */
1076	msg->msg.hdr.cmd = CMD_VERSION;
1077	msg->msg.hdr.len = 2;
1078	msg->msg.version.rsvd = 0;
1079	msg->msg.version.flags = 0;
1080	msg->msg.version.drv_version = 0;
1081
1082	err = esd_usb2_send_msg(dev, msg);
1083	if (err < 0) {
1084		dev_err(&intf->dev, "sending version message failed\n");
1085		goto free_msg;
1086	}
1087
1088	err = esd_usb2_wait_msg(dev, msg);
1089	if (err < 0) {
1090		dev_err(&intf->dev, "no version message answer\n");
1091		goto free_msg;
1092	}
1093
1094	dev->net_count = (int)msg->msg.version_reply.nets;
1095	dev->version = le32_to_cpu(msg->msg.version_reply.version);
1096
1097	if (device_create_file(&intf->dev, &dev_attr_firmware))
1098		dev_err(&intf->dev,
1099			"Couldn't create device file for firmware\n");
1100
1101	if (device_create_file(&intf->dev, &dev_attr_hardware))
1102		dev_err(&intf->dev,
1103			"Couldn't create device file for hardware\n");
1104
1105	if (device_create_file(&intf->dev, &dev_attr_nets))
1106		dev_err(&intf->dev,
1107			"Couldn't create device file for nets\n");
1108
1109	/* do per device probing */
1110	for (i = 0; i < dev->net_count; i++)
1111		esd_usb2_probe_one_net(intf, i);
1112
1113free_msg:
1114	kfree(msg);
1115	if (err)
1116		kfree(dev);
1117done:
1118	return err;
1119}
1120
1121/*
1122 * called by the usb core when the device is removed from the system
1123 */
1124static void esd_usb2_disconnect(struct usb_interface *intf)
1125{
1126	struct esd_usb2 *dev = usb_get_intfdata(intf);
1127	struct net_device *netdev;
1128	int i;
1129
1130	device_remove_file(&intf->dev, &dev_attr_firmware);
1131	device_remove_file(&intf->dev, &dev_attr_hardware);
1132	device_remove_file(&intf->dev, &dev_attr_nets);
1133
1134	usb_set_intfdata(intf, NULL);
1135
1136	if (dev) {
1137		for (i = 0; i < dev->net_count; i++) {
1138			if (dev->nets[i]) {
1139				netdev = dev->nets[i]->netdev;
1140				unregister_netdev(netdev);
1141				free_candev(netdev);
1142			}
1143		}
1144		unlink_all_urbs(dev);
1145		kfree(dev);
1146	}
1147}
1148
1149/* usb specific object needed to register this driver with the usb subsystem */
1150static struct usb_driver esd_usb2_driver = {
1151	.name = "esd_usb2",
1152	.probe = esd_usb2_probe,
1153	.disconnect = esd_usb2_disconnect,
1154	.id_table = esd_usb2_table,
1155};
1156
1157module_usb_driver(esd_usb2_driver);