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   1/*
   2 * CAN driver for esd CAN-USB/2
   3 *
   4 * Copyright (C) 2010 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License as published
   8 * by the Free Software Foundation; version 2 of the License.
   9 *
  10 * This program is distributed in the hope that it will be useful, but
  11 * WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 * General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License along
  16 * with this program; if not, write to the Free Software Foundation, Inc.,
  17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19#include <linux/init.h>
  20#include <linux/signal.h>
  21#include <linux/slab.h>
  22#include <linux/module.h>
  23#include <linux/netdevice.h>
  24#include <linux/usb.h>
  25
  26#include <linux/can.h>
  27#include <linux/can/dev.h>
  28#include <linux/can/error.h>
  29
  30MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
  31MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 interfaces");
  32MODULE_LICENSE("GPL v2");
  33
  34/* Define these values to match your devices */
  35#define USB_ESDGMBH_VENDOR_ID	0x0ab4
  36#define USB_CANUSB2_PRODUCT_ID	0x0010
  37
  38#define ESD_USB2_CAN_CLOCK	60000000
  39#define ESD_USB2_MAX_NETS	2
  40
  41/* USB2 commands */
  42#define CMD_VERSION		1 /* also used for VERSION_REPLY */
  43#define CMD_CAN_RX		2 /* device to host only */
  44#define CMD_CAN_TX		3 /* also used for TX_DONE */
  45#define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
  46#define CMD_TS			5 /* also used for TS_REPLY */
  47#define CMD_IDADD		6 /* also used for IDADD_REPLY */
  48
  49/* esd CAN message flags - dlc field */
  50#define ESD_RTR			0x10
  51
  52/* esd CAN message flags - id field */
  53#define ESD_EXTID		0x20000000
  54#define ESD_EVENT		0x40000000
  55#define ESD_IDMASK		0x1fffffff
  56
  57/* esd CAN event ids used by this driver */
  58#define ESD_EV_CAN_ERROR_EXT	2
  59
  60/* baudrate message flags */
  61#define ESD_USB2_UBR		0x80000000
  62#define ESD_USB2_LOM		0x40000000
  63#define ESD_USB2_NO_BAUDRATE	0x7fffffff
  64#define ESD_USB2_TSEG1_MIN	1
  65#define ESD_USB2_TSEG1_MAX	16
  66#define ESD_USB2_TSEG1_SHIFT	16
  67#define ESD_USB2_TSEG2_MIN	1
  68#define ESD_USB2_TSEG2_MAX	8
  69#define ESD_USB2_TSEG2_SHIFT	20
  70#define ESD_USB2_SJW_MAX	4
  71#define ESD_USB2_SJW_SHIFT	14
  72#define ESD_USB2_BRP_MIN	1
  73#define ESD_USB2_BRP_MAX	1024
  74#define ESD_USB2_BRP_INC	1
  75#define ESD_USB2_3_SAMPLES	0x00800000
  76
  77/* esd IDADD message */
  78#define ESD_ID_ENABLE		0x80
  79#define ESD_MAX_ID_SEGMENT	64
  80
  81/* SJA1000 ECC register (emulated by usb2 firmware) */
  82#define SJA1000_ECC_SEG		0x1F
  83#define SJA1000_ECC_DIR		0x20
  84#define SJA1000_ECC_ERR		0x06
  85#define SJA1000_ECC_BIT		0x00
  86#define SJA1000_ECC_FORM	0x40
  87#define SJA1000_ECC_STUFF	0x80
  88#define SJA1000_ECC_MASK	0xc0
  89
  90/* esd bus state event codes */
  91#define ESD_BUSSTATE_MASK	0xc0
  92#define ESD_BUSSTATE_WARN	0x40
  93#define ESD_BUSSTATE_ERRPASSIVE	0x80
  94#define ESD_BUSSTATE_BUSOFF	0xc0
  95
  96#define RX_BUFFER_SIZE		1024
  97#define MAX_RX_URBS		4
  98#define MAX_TX_URBS		16 /* must be power of 2 */
  99
 100struct header_msg {
 101	u8 len; /* len is always the total message length in 32bit words */
 102	u8 cmd;
 103	u8 rsvd[2];
 104};
 105
 106struct version_msg {
 107	u8 len;
 108	u8 cmd;
 109	u8 rsvd;
 110	u8 flags;
 111	__le32 drv_version;
 112};
 113
 114struct version_reply_msg {
 115	u8 len;
 116	u8 cmd;
 117	u8 nets;
 118	u8 features;
 119	__le32 version;
 120	u8 name[16];
 121	__le32 rsvd;
 122	__le32 ts;
 123};
 124
 125struct rx_msg {
 126	u8 len;
 127	u8 cmd;
 128	u8 net;
 129	u8 dlc;
 130	__le32 ts;
 131	__le32 id; /* upper 3 bits contain flags */
 132	u8 data[8];
 133};
 134
 135struct tx_msg {
 136	u8 len;
 137	u8 cmd;
 138	u8 net;
 139	u8 dlc;
 140	__le32 hnd;
 141	__le32 id; /* upper 3 bits contain flags */
 142	u8 data[8];
 143};
 144
 145struct tx_done_msg {
 146	u8 len;
 147	u8 cmd;
 148	u8 net;
 149	u8 status;
 150	__le32 hnd;
 151	__le32 ts;
 152};
 153
 154struct id_filter_msg {
 155	u8 len;
 156	u8 cmd;
 157	u8 net;
 158	u8 option;
 159	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
 160};
 161
 162struct set_baudrate_msg {
 163	u8 len;
 164	u8 cmd;
 165	u8 net;
 166	u8 rsvd;
 167	__le32 baud;
 168};
 169
 170/* Main message type used between library and application */
 171struct __attribute__ ((packed)) esd_usb2_msg {
 172	union {
 173		struct header_msg hdr;
 174		struct version_msg version;
 175		struct version_reply_msg version_reply;
 176		struct rx_msg rx;
 177		struct tx_msg tx;
 178		struct tx_done_msg txdone;
 179		struct set_baudrate_msg setbaud;
 180		struct id_filter_msg filter;
 181	} msg;
 182};
 183
 184static struct usb_device_id esd_usb2_table[] = {
 185	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
 186	{}
 187};
 188MODULE_DEVICE_TABLE(usb, esd_usb2_table);
 189
 190struct esd_usb2_net_priv;
 191
 192struct esd_tx_urb_context {
 193	struct esd_usb2_net_priv *priv;
 194	u32 echo_index;
 195	int dlc;
 196};
 197
 198struct esd_usb2 {
 199	struct usb_device *udev;
 200	struct esd_usb2_net_priv *nets[ESD_USB2_MAX_NETS];
 201
 202	struct usb_anchor rx_submitted;
 203
 204	int net_count;
 205	u32 version;
 206	int rxinitdone;
 207};
 208
 209struct esd_usb2_net_priv {
 210	struct can_priv can; /* must be the first member */
 211
 212	atomic_t active_tx_jobs;
 213	struct usb_anchor tx_submitted;
 214	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
 215
 216	int open_time;
 217	struct esd_usb2 *usb2;
 218	struct net_device *netdev;
 219	int index;
 220	u8 old_state;
 221	struct can_berr_counter bec;
 222};
 223
 224static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
 225			      struct esd_usb2_msg *msg)
 226{
 227	struct net_device_stats *stats = &priv->netdev->stats;
 228	struct can_frame *cf;
 229	struct sk_buff *skb;
 230	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
 231
 232	if (id == ESD_EV_CAN_ERROR_EXT) {
 233		u8 state = msg->msg.rx.data[0];
 234		u8 ecc = msg->msg.rx.data[1];
 235		u8 txerr = msg->msg.rx.data[2];
 236		u8 rxerr = msg->msg.rx.data[3];
 237
 238		skb = alloc_can_err_skb(priv->netdev, &cf);
 239		if (skb == NULL) {
 240			stats->rx_dropped++;
 241			return;
 242		}
 243
 244		if (state != priv->old_state) {
 245			priv->old_state = state;
 246
 247			switch (state & ESD_BUSSTATE_MASK) {
 248			case ESD_BUSSTATE_BUSOFF:
 249				priv->can.state = CAN_STATE_BUS_OFF;
 250				cf->can_id |= CAN_ERR_BUSOFF;
 251				can_bus_off(priv->netdev);
 252				break;
 253			case ESD_BUSSTATE_WARN:
 254				priv->can.state = CAN_STATE_ERROR_WARNING;
 255				priv->can.can_stats.error_warning++;
 256				break;
 257			case ESD_BUSSTATE_ERRPASSIVE:
 258				priv->can.state = CAN_STATE_ERROR_PASSIVE;
 259				priv->can.can_stats.error_passive++;
 260				break;
 261			default:
 262				priv->can.state = CAN_STATE_ERROR_ACTIVE;
 263				break;
 264			}
 265		} else {
 266			priv->can.can_stats.bus_error++;
 267			stats->rx_errors++;
 268
 269			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 270
 271			switch (ecc & SJA1000_ECC_MASK) {
 272			case SJA1000_ECC_BIT:
 273				cf->data[2] |= CAN_ERR_PROT_BIT;
 274				break;
 275			case SJA1000_ECC_FORM:
 276				cf->data[2] |= CAN_ERR_PROT_FORM;
 277				break;
 278			case SJA1000_ECC_STUFF:
 279				cf->data[2] |= CAN_ERR_PROT_STUFF;
 280				break;
 281			default:
 282				cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 283				cf->data[3] = ecc & SJA1000_ECC_SEG;
 284				break;
 285			}
 286
 287			/* Error occurred during transmission? */
 288			if (!(ecc & SJA1000_ECC_DIR))
 289				cf->data[2] |= CAN_ERR_PROT_TX;
 290
 291			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
 292			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
 293				cf->data[1] = (txerr > rxerr) ?
 294					CAN_ERR_CRTL_TX_PASSIVE :
 295					CAN_ERR_CRTL_RX_PASSIVE;
 296			}
 297			cf->data[6] = txerr;
 298			cf->data[7] = rxerr;
 299		}
 300
 301		netif_rx(skb);
 302
 303		priv->bec.txerr = txerr;
 304		priv->bec.rxerr = rxerr;
 305
 306		stats->rx_packets++;
 307		stats->rx_bytes += cf->can_dlc;
 308	}
 309}
 310
 311static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
 312				struct esd_usb2_msg *msg)
 313{
 314	struct net_device_stats *stats = &priv->netdev->stats;
 315	struct can_frame *cf;
 316	struct sk_buff *skb;
 317	int i;
 318	u32 id;
 319
 320	if (!netif_device_present(priv->netdev))
 321		return;
 322
 323	id = le32_to_cpu(msg->msg.rx.id);
 324
 325	if (id & ESD_EVENT) {
 326		esd_usb2_rx_event(priv, msg);
 327	} else {
 328		skb = alloc_can_skb(priv->netdev, &cf);
 329		if (skb == NULL) {
 330			stats->rx_dropped++;
 331			return;
 332		}
 333
 334		cf->can_id = id & ESD_IDMASK;
 335		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc);
 336
 337		if (id & ESD_EXTID)
 338			cf->can_id |= CAN_EFF_FLAG;
 339
 340		if (msg->msg.rx.dlc & ESD_RTR) {
 341			cf->can_id |= CAN_RTR_FLAG;
 342		} else {
 343			for (i = 0; i < cf->can_dlc; i++)
 344				cf->data[i] = msg->msg.rx.data[i];
 345		}
 346
 347		netif_rx(skb);
 348
 349		stats->rx_packets++;
 350		stats->rx_bytes += cf->can_dlc;
 351	}
 352
 353	return;
 354}
 355
 356static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
 357				 struct esd_usb2_msg *msg)
 358{
 359	struct net_device_stats *stats = &priv->netdev->stats;
 360	struct net_device *netdev = priv->netdev;
 361	struct esd_tx_urb_context *context;
 362
 363	if (!netif_device_present(netdev))
 364		return;
 365
 366	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
 367
 368	if (!msg->msg.txdone.status) {
 369		stats->tx_packets++;
 370		stats->tx_bytes += context->dlc;
 371		can_get_echo_skb(netdev, context->echo_index);
 372	} else {
 373		stats->tx_errors++;
 374		can_free_echo_skb(netdev, context->echo_index);
 375	}
 376
 377	/* Release context */
 378	context->echo_index = MAX_TX_URBS;
 379	atomic_dec(&priv->active_tx_jobs);
 380
 381	netif_wake_queue(netdev);
 382}
 383
 384static void esd_usb2_read_bulk_callback(struct urb *urb)
 385{
 386	struct esd_usb2 *dev = urb->context;
 387	int retval;
 388	int pos = 0;
 389	int i;
 390
 391	switch (urb->status) {
 392	case 0: /* success */
 393		break;
 394
 395	case -ENOENT:
 396	case -ESHUTDOWN:
 397		return;
 398
 399	default:
 400		dev_info(dev->udev->dev.parent,
 401			 "Rx URB aborted (%d)\n", urb->status);
 402		goto resubmit_urb;
 403	}
 404
 405	while (pos < urb->actual_length) {
 406		struct esd_usb2_msg *msg;
 407
 408		msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
 409
 410		switch (msg->msg.hdr.cmd) {
 411		case CMD_CAN_RX:
 412			esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
 413			break;
 414
 415		case CMD_CAN_TX:
 416			esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
 417					     msg);
 418			break;
 419		}
 420
 421		pos += msg->msg.hdr.len << 2;
 422
 423		if (pos > urb->actual_length) {
 424			dev_err(dev->udev->dev.parent, "format error\n");
 425			break;
 426		}
 427	}
 428
 429resubmit_urb:
 430	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
 431			  urb->transfer_buffer, RX_BUFFER_SIZE,
 432			  esd_usb2_read_bulk_callback, dev);
 433
 434	retval = usb_submit_urb(urb, GFP_ATOMIC);
 435	if (retval == -ENODEV) {
 436		for (i = 0; i < dev->net_count; i++) {
 437			if (dev->nets[i])
 438				netif_device_detach(dev->nets[i]->netdev);
 439		}
 440	} else if (retval) {
 441		dev_err(dev->udev->dev.parent,
 442			"failed resubmitting read bulk urb: %d\n", retval);
 443	}
 444
 445	return;
 446}
 447
 448/*
 449 * callback for bulk IN urb
 450 */
 451static void esd_usb2_write_bulk_callback(struct urb *urb)
 452{
 453	struct esd_tx_urb_context *context = urb->context;
 454	struct esd_usb2_net_priv *priv;
 455	struct esd_usb2 *dev;
 456	struct net_device *netdev;
 457	size_t size = sizeof(struct esd_usb2_msg);
 458
 459	WARN_ON(!context);
 460
 461	priv = context->priv;
 462	netdev = priv->netdev;
 463	dev = priv->usb2;
 464
 465	/* free up our allocated buffer */
 466	usb_free_coherent(urb->dev, size,
 467			  urb->transfer_buffer, urb->transfer_dma);
 468
 469	if (!netif_device_present(netdev))
 470		return;
 471
 472	if (urb->status)
 473		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 474
 475	netdev->trans_start = jiffies;
 476}
 477
 478static ssize_t show_firmware(struct device *d,
 479			     struct device_attribute *attr, char *buf)
 480{
 481	struct usb_interface *intf = to_usb_interface(d);
 482	struct esd_usb2 *dev = usb_get_intfdata(intf);
 483
 484	return sprintf(buf, "%d.%d.%d\n",
 485		       (dev->version >> 12) & 0xf,
 486		       (dev->version >> 8) & 0xf,
 487		       dev->version & 0xff);
 488}
 489static DEVICE_ATTR(firmware, S_IRUGO, show_firmware, NULL);
 490
 491static ssize_t show_hardware(struct device *d,
 492			     struct device_attribute *attr, char *buf)
 493{
 494	struct usb_interface *intf = to_usb_interface(d);
 495	struct esd_usb2 *dev = usb_get_intfdata(intf);
 496
 497	return sprintf(buf, "%d.%d.%d\n",
 498		       (dev->version >> 28) & 0xf,
 499		       (dev->version >> 24) & 0xf,
 500		       (dev->version >> 16) & 0xff);
 501}
 502static DEVICE_ATTR(hardware, S_IRUGO, show_hardware, NULL);
 503
 504static ssize_t show_nets(struct device *d,
 505			 struct device_attribute *attr, char *buf)
 506{
 507	struct usb_interface *intf = to_usb_interface(d);
 508	struct esd_usb2 *dev = usb_get_intfdata(intf);
 509
 510	return sprintf(buf, "%d", dev->net_count);
 511}
 512static DEVICE_ATTR(nets, S_IRUGO, show_nets, NULL);
 513
 514static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
 515{
 516	int actual_length;
 517
 518	return usb_bulk_msg(dev->udev,
 519			    usb_sndbulkpipe(dev->udev, 2),
 520			    msg,
 521			    msg->msg.hdr.len << 2,
 522			    &actual_length,
 523			    1000);
 524}
 525
 526static int esd_usb2_wait_msg(struct esd_usb2 *dev,
 527			     struct esd_usb2_msg *msg)
 528{
 529	int actual_length;
 530
 531	return usb_bulk_msg(dev->udev,
 532			    usb_rcvbulkpipe(dev->udev, 1),
 533			    msg,
 534			    sizeof(*msg),
 535			    &actual_length,
 536			    1000);
 537}
 538
 539static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
 540{
 541	int i, err = 0;
 542
 543	if (dev->rxinitdone)
 544		return 0;
 545
 546	for (i = 0; i < MAX_RX_URBS; i++) {
 547		struct urb *urb = NULL;
 548		u8 *buf = NULL;
 549
 550		/* create a URB, and a buffer for it */
 551		urb = usb_alloc_urb(0, GFP_KERNEL);
 552		if (!urb) {
 553			dev_warn(dev->udev->dev.parent,
 554				 "No memory left for URBs\n");
 555			err = -ENOMEM;
 556			break;
 557		}
 558
 559		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 560					 &urb->transfer_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		usb_fill_bulk_urb(urb, dev->udev,
 569				  usb_rcvbulkpipe(dev->udev, 1),
 570				  buf, RX_BUFFER_SIZE,
 571				  esd_usb2_read_bulk_callback, dev);
 572		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 573		usb_anchor_urb(urb, &dev->rx_submitted);
 574
 575		err = usb_submit_urb(urb, GFP_KERNEL);
 576		if (err) {
 577			usb_unanchor_urb(urb);
 578			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 579					  urb->transfer_dma);
 580		}
 581
 582freeurb:
 583		/* Drop reference, USB core will take care of freeing it */
 584		usb_free_urb(urb);
 585		if (err)
 586			break;
 587	}
 588
 589	/* Did we submit any URBs */
 590	if (i == 0) {
 591		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
 592		return err;
 593	}
 594
 595	/* Warn if we've couldn't transmit all the URBs */
 596	if (i < MAX_RX_URBS) {
 597		dev_warn(dev->udev->dev.parent,
 598			 "rx performance may be slow\n");
 599	}
 600
 601	dev->rxinitdone = 1;
 602	return 0;
 603}
 604
 605/*
 606 * Start interface
 607 */
 608static int esd_usb2_start(struct esd_usb2_net_priv *priv)
 609{
 610	struct esd_usb2 *dev = priv->usb2;
 611	struct net_device *netdev = priv->netdev;
 612	struct esd_usb2_msg msg;
 613	int err, i;
 614
 615	/*
 616	 * Enable all IDs
 617	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
 618	 * Each bit represents one 11 bit CAN identifier. A set bit
 619	 * enables reception of the corresponding CAN identifier. A cleared
 620	 * bit disabled this identifier. An additional bitmask value
 621	 * following the CAN 2.0A bits is used to enable reception of
 622	 * extended CAN frames. Only the LSB of this final mask is checked
 623	 * for the complete 29 bit ID range. The IDADD message also allows
 624	 * filter configuration for an ID subset. In this case you can add
 625	 * the number of the starting bitmask (0..64) to the filter.option
 626	 * field followed by only some bitmasks.
 627	 */
 628	msg.msg.hdr.cmd = CMD_IDADD;
 629	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 630	msg.msg.filter.net = priv->index;
 631	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 632	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
 633		msg.msg.filter.mask[i] = cpu_to_le32(0xffffffff);
 634	/* enable 29bit extended IDs */
 635	msg.msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
 636
 637	err = esd_usb2_send_msg(dev, &msg);
 638	if (err)
 639		goto failed;
 640
 641	err = esd_usb2_setup_rx_urbs(dev);
 642	if (err)
 643		goto failed;
 644
 645	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 646
 647	return 0;
 648
 649failed:
 650	if (err == -ENODEV)
 651		netif_device_detach(netdev);
 652
 653	netdev_err(netdev, "couldn't start device: %d\n", err);
 654
 655	return err;
 656}
 657
 658static void unlink_all_urbs(struct esd_usb2 *dev)
 659{
 660	struct esd_usb2_net_priv *priv;
 661	int i, j;
 662
 663	usb_kill_anchored_urbs(&dev->rx_submitted);
 664	for (i = 0; i < dev->net_count; i++) {
 665		priv = dev->nets[i];
 666		if (priv) {
 667			usb_kill_anchored_urbs(&priv->tx_submitted);
 668			atomic_set(&priv->active_tx_jobs, 0);
 669
 670			for (j = 0; j < MAX_TX_URBS; j++)
 671				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
 672		}
 673	}
 674}
 675
 676static int esd_usb2_open(struct net_device *netdev)
 677{
 678	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 679	int err;
 680
 681	/* common open */
 682	err = open_candev(netdev);
 683	if (err)
 684		return err;
 685
 686	/* finally start device */
 687	err = esd_usb2_start(priv);
 688	if (err) {
 689		netdev_warn(netdev, "couldn't start device: %d\n", err);
 690		close_candev(netdev);
 691		return err;
 692	}
 693
 694	priv->open_time = jiffies;
 695
 696	netif_start_queue(netdev);
 697
 698	return 0;
 699}
 700
 701static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
 702				      struct net_device *netdev)
 703{
 704	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 705	struct esd_usb2 *dev = priv->usb2;
 706	struct esd_tx_urb_context *context = NULL;
 707	struct net_device_stats *stats = &netdev->stats;
 708	struct can_frame *cf = (struct can_frame *)skb->data;
 709	struct esd_usb2_msg *msg;
 710	struct urb *urb;
 711	u8 *buf;
 712	int i, err;
 713	int ret = NETDEV_TX_OK;
 714	size_t size = sizeof(struct esd_usb2_msg);
 715
 716	if (can_dropped_invalid_skb(netdev, skb))
 717		return NETDEV_TX_OK;
 718
 719	/* create a URB, and a buffer for it, and copy the data to the URB */
 720	urb = usb_alloc_urb(0, GFP_ATOMIC);
 721	if (!urb) {
 722		netdev_err(netdev, "No memory left for URBs\n");
 723		stats->tx_dropped++;
 724		dev_kfree_skb(skb);
 725		goto nourbmem;
 726	}
 727
 728	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
 729				 &urb->transfer_dma);
 730	if (!buf) {
 731		netdev_err(netdev, "No memory left for USB buffer\n");
 732		stats->tx_dropped++;
 733		dev_kfree_skb(skb);
 734		goto nobufmem;
 735	}
 736
 737	msg = (struct esd_usb2_msg *)buf;
 738
 739	msg->msg.hdr.len = 3; /* minimal length */
 740	msg->msg.hdr.cmd = CMD_CAN_TX;
 741	msg->msg.tx.net = priv->index;
 742	msg->msg.tx.dlc = cf->can_dlc;
 743	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
 744
 745	if (cf->can_id & CAN_RTR_FLAG)
 746		msg->msg.tx.dlc |= ESD_RTR;
 747
 748	if (cf->can_id & CAN_EFF_FLAG)
 749		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
 750
 751	for (i = 0; i < cf->can_dlc; i++)
 752		msg->msg.tx.data[i] = cf->data[i];
 753
 754	msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
 755
 756	for (i = 0; i < MAX_TX_URBS; i++) {
 757		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 758			context = &priv->tx_contexts[i];
 759			break;
 760		}
 761	}
 762
 763	/*
 764	 * This may never happen.
 765	 */
 766	if (!context) {
 767		netdev_warn(netdev, "couldn't find free context\n");
 768		ret = NETDEV_TX_BUSY;
 769		goto releasebuf;
 770	}
 771
 772	context->priv = priv;
 773	context->echo_index = i;
 774	context->dlc = cf->can_dlc;
 775
 776	/* hnd must not be 0 - MSB is stripped in txdone handling */
 777	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
 778
 779	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 780			  msg->msg.hdr.len << 2,
 781			  esd_usb2_write_bulk_callback, context);
 782
 783	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 784
 785	usb_anchor_urb(urb, &priv->tx_submitted);
 786
 787	can_put_echo_skb(skb, netdev, context->echo_index);
 788
 789	atomic_inc(&priv->active_tx_jobs);
 790
 791	/* Slow down tx path */
 792	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
 793		netif_stop_queue(netdev);
 794
 795	err = usb_submit_urb(urb, GFP_ATOMIC);
 796	if (err) {
 797		can_free_echo_skb(netdev, context->echo_index);
 798
 799		atomic_dec(&priv->active_tx_jobs);
 800		usb_unanchor_urb(urb);
 801
 802		stats->tx_dropped++;
 803
 804		if (err == -ENODEV)
 805			netif_device_detach(netdev);
 806		else
 807			netdev_warn(netdev, "failed tx_urb %d\n", err);
 808
 809		goto releasebuf;
 810	}
 811
 812	netdev->trans_start = jiffies;
 813
 814	/*
 815	 * Release our reference to this URB, the USB core will eventually free
 816	 * it entirely.
 817	 */
 818	usb_free_urb(urb);
 819
 820	return NETDEV_TX_OK;
 821
 822releasebuf:
 823	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 824
 825nobufmem:
 826	usb_free_urb(urb);
 827
 828nourbmem:
 829	return ret;
 830}
 831
 832static int esd_usb2_close(struct net_device *netdev)
 833{
 834	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 835	struct esd_usb2_msg msg;
 836	int i;
 837
 838	/* Disable all IDs (see esd_usb2_start()) */
 839	msg.msg.hdr.cmd = CMD_IDADD;
 840	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 841	msg.msg.filter.net = priv->index;
 842	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 843	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
 844		msg.msg.filter.mask[i] = 0;
 845	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
 846		netdev_err(netdev, "sending idadd message failed\n");
 847
 848	/* set CAN controller to reset mode */
 849	msg.msg.hdr.len = 2;
 850	msg.msg.hdr.cmd = CMD_SETBAUD;
 851	msg.msg.setbaud.net = priv->index;
 852	msg.msg.setbaud.rsvd = 0;
 853	msg.msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
 854	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
 855		netdev_err(netdev, "sending setbaud message failed\n");
 856
 857	priv->can.state = CAN_STATE_STOPPED;
 858
 859	netif_stop_queue(netdev);
 860
 861	close_candev(netdev);
 862
 863	priv->open_time = 0;
 864
 865	return 0;
 866}
 867
 868static const struct net_device_ops esd_usb2_netdev_ops = {
 869	.ndo_open = esd_usb2_open,
 870	.ndo_stop = esd_usb2_close,
 871	.ndo_start_xmit = esd_usb2_start_xmit,
 872};
 873
 874static struct can_bittiming_const esd_usb2_bittiming_const = {
 875	.name = "esd_usb2",
 876	.tseg1_min = ESD_USB2_TSEG1_MIN,
 877	.tseg1_max = ESD_USB2_TSEG1_MAX,
 878	.tseg2_min = ESD_USB2_TSEG2_MIN,
 879	.tseg2_max = ESD_USB2_TSEG2_MAX,
 880	.sjw_max = ESD_USB2_SJW_MAX,
 881	.brp_min = ESD_USB2_BRP_MIN,
 882	.brp_max = ESD_USB2_BRP_MAX,
 883	.brp_inc = ESD_USB2_BRP_INC,
 884};
 885
 886static int esd_usb2_set_bittiming(struct net_device *netdev)
 887{
 888	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 889	struct can_bittiming *bt = &priv->can.bittiming;
 890	struct esd_usb2_msg msg;
 891	u32 canbtr;
 892
 893	canbtr = ESD_USB2_UBR;
 894	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
 895	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
 896		<< ESD_USB2_SJW_SHIFT;
 897	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
 898		   & (ESD_USB2_TSEG1_MAX - 1))
 899		<< ESD_USB2_TSEG1_SHIFT;
 900	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
 901		<< ESD_USB2_TSEG2_SHIFT;
 902	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 903		canbtr |= ESD_USB2_3_SAMPLES;
 904
 905	msg.msg.hdr.len = 2;
 906	msg.msg.hdr.cmd = CMD_SETBAUD;
 907	msg.msg.setbaud.net = priv->index;
 908	msg.msg.setbaud.rsvd = 0;
 909	msg.msg.setbaud.baud = cpu_to_le32(canbtr);
 910
 911	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
 912
 913	return esd_usb2_send_msg(priv->usb2, &msg);
 914}
 915
 916static int esd_usb2_get_berr_counter(const struct net_device *netdev,
 917				     struct can_berr_counter *bec)
 918{
 919	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 920
 921	bec->txerr = priv->bec.txerr;
 922	bec->rxerr = priv->bec.rxerr;
 923
 924	return 0;
 925}
 926
 927static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
 928{
 929	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 930
 931	if (!priv->open_time)
 932		return -EINVAL;
 933
 934	switch (mode) {
 935	case CAN_MODE_START:
 936		netif_wake_queue(netdev);
 937		break;
 938
 939	default:
 940		return -EOPNOTSUPP;
 941	}
 942
 943	return 0;
 944}
 945
 946static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
 947{
 948	struct esd_usb2 *dev = usb_get_intfdata(intf);
 949	struct net_device *netdev;
 950	struct esd_usb2_net_priv *priv;
 951	int err = 0;
 952	int i;
 953
 954	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
 955	if (!netdev) {
 956		dev_err(&intf->dev, "couldn't alloc candev\n");
 957		err = -ENOMEM;
 958		goto done;
 959	}
 960
 961	priv = netdev_priv(netdev);
 962
 963	init_usb_anchor(&priv->tx_submitted);
 964	atomic_set(&priv->active_tx_jobs, 0);
 965
 966	for (i = 0; i < MAX_TX_URBS; i++)
 967		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 968
 969	priv->usb2 = dev;
 970	priv->netdev = netdev;
 971	priv->index = index;
 972
 973	priv->can.state = CAN_STATE_STOPPED;
 974	priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
 975	priv->can.bittiming_const = &esd_usb2_bittiming_const;
 976	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
 977	priv->can.do_set_mode = esd_usb2_set_mode;
 978	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
 979	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 980
 981	netdev->flags |= IFF_ECHO; /* we support local echo */
 982
 983	netdev->netdev_ops = &esd_usb2_netdev_ops;
 984
 985	SET_NETDEV_DEV(netdev, &intf->dev);
 986
 987	err = register_candev(netdev);
 988	if (err) {
 989		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 990		free_candev(netdev);
 991		err = -ENOMEM;
 992		goto done;
 993	}
 994
 995	dev->nets[index] = priv;
 996	netdev_info(netdev, "device %s registered\n", netdev->name);
 997
 998done:
 999	return err;
1000}
1001
1002/*
1003 * probe function for new USB2 devices
1004 *
1005 * check version information and number of available
1006 * CAN interfaces
1007 */
1008static int esd_usb2_probe(struct usb_interface *intf,
1009			 const struct usb_device_id *id)
1010{
1011	struct esd_usb2 *dev;
1012	struct esd_usb2_msg msg;
1013	int i, err;
1014
1015	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1016	if (!dev) {
1017		err = -ENOMEM;
1018		goto done;
1019	}
1020
1021	dev->udev = interface_to_usbdev(intf);
1022
1023	init_usb_anchor(&dev->rx_submitted);
1024
1025	usb_set_intfdata(intf, dev);
1026
1027	/* query number of CAN interfaces (nets) */
1028	msg.msg.hdr.cmd = CMD_VERSION;
1029	msg.msg.hdr.len = 2;
1030	msg.msg.version.rsvd = 0;
1031	msg.msg.version.flags = 0;
1032	msg.msg.version.drv_version = 0;
1033
1034	err = esd_usb2_send_msg(dev, &msg);
1035	if (err < 0) {
1036		dev_err(&intf->dev, "sending version message failed\n");
1037		goto free_dev;
1038	}
1039
1040	err = esd_usb2_wait_msg(dev, &msg);
1041	if (err < 0) {
1042		dev_err(&intf->dev, "no version message answer\n");
1043		goto free_dev;
1044	}
1045
1046	dev->net_count = (int)msg.msg.version_reply.nets;
1047	dev->version = le32_to_cpu(msg.msg.version_reply.version);
1048
1049	if (device_create_file(&intf->dev, &dev_attr_firmware))
1050		dev_err(&intf->dev,
1051			"Couldn't create device file for firmware\n");
1052
1053	if (device_create_file(&intf->dev, &dev_attr_hardware))
1054		dev_err(&intf->dev,
1055			"Couldn't create device file for hardware\n");
1056
1057	if (device_create_file(&intf->dev, &dev_attr_nets))
1058		dev_err(&intf->dev,
1059			"Couldn't create device file for nets\n");
1060
1061	/* do per device probing */
1062	for (i = 0; i < dev->net_count; i++)
1063		esd_usb2_probe_one_net(intf, i);
1064
1065	return 0;
1066
1067free_dev:
1068	kfree(dev);
1069done:
1070	return err;
1071}
1072
1073/*
1074 * called by the usb core when the device is removed from the system
1075 */
1076static void esd_usb2_disconnect(struct usb_interface *intf)
1077{
1078	struct esd_usb2 *dev = usb_get_intfdata(intf);
1079	struct net_device *netdev;
1080	int i;
1081
1082	device_remove_file(&intf->dev, &dev_attr_firmware);
1083	device_remove_file(&intf->dev, &dev_attr_hardware);
1084	device_remove_file(&intf->dev, &dev_attr_nets);
1085
1086	usb_set_intfdata(intf, NULL);
1087
1088	if (dev) {
1089		for (i = 0; i < dev->net_count; i++) {
1090			if (dev->nets[i]) {
1091				netdev = dev->nets[i]->netdev;
1092				unregister_netdev(netdev);
1093				free_candev(netdev);
1094			}
1095		}
1096		unlink_all_urbs(dev);
1097	}
1098}
1099
1100/* usb specific object needed to register this driver with the usb subsystem */
1101static struct usb_driver esd_usb2_driver = {
1102	.name = "esd_usb2",
1103	.probe = esd_usb2_probe,
1104	.disconnect = esd_usb2_disconnect,
1105	.id_table = esd_usb2_table,
1106};
1107
1108module_usb_driver(esd_usb2_driver);