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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		dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
 474			 urb->status);
 475
 476	netdev->trans_start = jiffies;
 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, S_IRUGO, 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, S_IRUGO, 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, S_IRUGO, 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
 551		/* create a URB, and a buffer for it */
 552		urb = usb_alloc_urb(0, GFP_KERNEL);
 553		if (!urb) {
 554			dev_warn(dev->udev->dev.parent,
 555				 "No memory left for URBs\n");
 556			err = -ENOMEM;
 557			break;
 558		}
 559
 560		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 561					 &urb->transfer_dma);
 562		if (!buf) {
 563			dev_warn(dev->udev->dev.parent,
 564				 "No memory left for USB buffer\n");
 565			err = -ENOMEM;
 566			goto freeurb;
 567		}
 568
 569		usb_fill_bulk_urb(urb, dev->udev,
 570				  usb_rcvbulkpipe(dev->udev, 1),
 571				  buf, RX_BUFFER_SIZE,
 572				  esd_usb2_read_bulk_callback, dev);
 573		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 574		usb_anchor_urb(urb, &dev->rx_submitted);
 575
 576		err = usb_submit_urb(urb, GFP_KERNEL);
 577		if (err) {
 578			usb_unanchor_urb(urb);
 579			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 580					  urb->transfer_dma);
 581		}
 582
 583freeurb:
 584		/* Drop reference, USB core will take care of freeing it */
 585		usb_free_urb(urb);
 586		if (err)
 587			break;
 588	}
 589
 590	/* Did we submit any URBs */
 591	if (i == 0) {
 592		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
 593		return err;
 594	}
 595
 596	/* Warn if we've couldn't transmit all the URBs */
 597	if (i < MAX_RX_URBS) {
 598		dev_warn(dev->udev->dev.parent,
 599			 "rx performance may be slow\n");
 600	}
 601
 602	dev->rxinitdone = 1;
 603	return 0;
 604}
 605
 606/*
 607 * Start interface
 608 */
 609static int esd_usb2_start(struct esd_usb2_net_priv *priv)
 610{
 611	struct esd_usb2 *dev = priv->usb2;
 612	struct net_device *netdev = priv->netdev;
 613	struct esd_usb2_msg msg;
 614	int err, i;
 615
 616	/*
 617	 * Enable all IDs
 618	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
 619	 * Each bit represents one 11 bit CAN identifier. A set bit
 620	 * enables reception of the corresponding CAN identifier. A cleared
 621	 * bit disabled this identifier. An additional bitmask value
 622	 * following the CAN 2.0A bits is used to enable reception of
 623	 * extended CAN frames. Only the LSB of this final mask is checked
 624	 * for the complete 29 bit ID range. The IDADD message also allows
 625	 * filter configuration for an ID subset. In this case you can add
 626	 * the number of the starting bitmask (0..64) to the filter.option
 627	 * field followed by only some bitmasks.
 628	 */
 629	msg.msg.hdr.cmd = CMD_IDADD;
 630	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 631	msg.msg.filter.net = priv->index;
 632	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 633	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
 634		msg.msg.filter.mask[i] = cpu_to_le32(0xffffffff);
 635	/* enable 29bit extended IDs */
 636	msg.msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
 637
 638	err = esd_usb2_send_msg(dev, &msg);
 639	if (err)
 640		goto failed;
 641
 642	err = esd_usb2_setup_rx_urbs(dev);
 643	if (err)
 644		goto failed;
 645
 646	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 647
 648	return 0;
 649
 650failed:
 651	if (err == -ENODEV)
 652		netif_device_detach(netdev);
 653
 654	dev_err(netdev->dev.parent, "couldn't start device: %d\n", err);
 655
 656	return err;
 657}
 658
 659static void unlink_all_urbs(struct esd_usb2 *dev)
 660{
 661	struct esd_usb2_net_priv *priv;
 662	int i, j;
 663
 664	usb_kill_anchored_urbs(&dev->rx_submitted);
 665	for (i = 0; i < dev->net_count; i++) {
 666		priv = dev->nets[i];
 667		if (priv) {
 668			usb_kill_anchored_urbs(&priv->tx_submitted);
 669			atomic_set(&priv->active_tx_jobs, 0);
 670
 671			for (j = 0; j < MAX_TX_URBS; j++)
 672				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
 673		}
 674	}
 675}
 676
 677static int esd_usb2_open(struct net_device *netdev)
 678{
 679	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 680	int err;
 681
 682	/* common open */
 683	err = open_candev(netdev);
 684	if (err)
 685		return err;
 686
 687	/* finally start device */
 688	err = esd_usb2_start(priv);
 689	if (err) {
 690		dev_warn(netdev->dev.parent,
 691			 "couldn't start device: %d\n", err);
 692		close_candev(netdev);
 693		return err;
 694	}
 695
 696	priv->open_time = jiffies;
 697
 698	netif_start_queue(netdev);
 699
 700	return 0;
 701}
 702
 703static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
 704				      struct net_device *netdev)
 705{
 706	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 707	struct esd_usb2 *dev = priv->usb2;
 708	struct esd_tx_urb_context *context = NULL;
 709	struct net_device_stats *stats = &netdev->stats;
 710	struct can_frame *cf = (struct can_frame *)skb->data;
 711	struct esd_usb2_msg *msg;
 712	struct urb *urb;
 713	u8 *buf;
 714	int i, err;
 715	int ret = NETDEV_TX_OK;
 716	size_t size = sizeof(struct esd_usb2_msg);
 717
 718	if (can_dropped_invalid_skb(netdev, skb))
 719		return NETDEV_TX_OK;
 720
 721	/* create a URB, and a buffer for it, and copy the data to the URB */
 722	urb = usb_alloc_urb(0, GFP_ATOMIC);
 723	if (!urb) {
 724		dev_err(netdev->dev.parent, "No memory left for URBs\n");
 725		stats->tx_dropped++;
 726		dev_kfree_skb(skb);
 727		goto nourbmem;
 728	}
 729
 730	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
 731				 &urb->transfer_dma);
 732	if (!buf) {
 733		dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
 734		stats->tx_dropped++;
 735		dev_kfree_skb(skb);
 736		goto nobufmem;
 737	}
 738
 739	msg = (struct esd_usb2_msg *)buf;
 740
 741	msg->msg.hdr.len = 3; /* minimal length */
 742	msg->msg.hdr.cmd = CMD_CAN_TX;
 743	msg->msg.tx.net = priv->index;
 744	msg->msg.tx.dlc = cf->can_dlc;
 745	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
 746
 747	if (cf->can_id & CAN_RTR_FLAG)
 748		msg->msg.tx.dlc |= ESD_RTR;
 749
 750	if (cf->can_id & CAN_EFF_FLAG)
 751		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
 752
 753	for (i = 0; i < cf->can_dlc; i++)
 754		msg->msg.tx.data[i] = cf->data[i];
 755
 756	msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
 757
 758	for (i = 0; i < MAX_TX_URBS; i++) {
 759		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 760			context = &priv->tx_contexts[i];
 761			break;
 762		}
 763	}
 764
 765	/*
 766	 * This may never happen.
 767	 */
 768	if (!context) {
 769		dev_warn(netdev->dev.parent, "couldn't find free context\n");
 770		ret = NETDEV_TX_BUSY;
 771		goto releasebuf;
 772	}
 773
 774	context->priv = priv;
 775	context->echo_index = i;
 776	context->dlc = cf->can_dlc;
 777
 778	/* hnd must not be 0 - MSB is stripped in txdone handling */
 779	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
 780
 781	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 782			  msg->msg.hdr.len << 2,
 783			  esd_usb2_write_bulk_callback, context);
 784
 785	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 786
 787	usb_anchor_urb(urb, &priv->tx_submitted);
 788
 789	can_put_echo_skb(skb, netdev, context->echo_index);
 790
 791	atomic_inc(&priv->active_tx_jobs);
 792
 793	/* Slow down tx path */
 794	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
 795		netif_stop_queue(netdev);
 796
 797	err = usb_submit_urb(urb, GFP_ATOMIC);
 798	if (err) {
 799		can_free_echo_skb(netdev, context->echo_index);
 800
 801		atomic_dec(&priv->active_tx_jobs);
 802		usb_unanchor_urb(urb);
 803
 804		stats->tx_dropped++;
 805
 806		if (err == -ENODEV)
 807			netif_device_detach(netdev);
 808		else
 809			dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
 810
 811		goto releasebuf;
 812	}
 813
 814	netdev->trans_start = jiffies;
 815
 816	/*
 817	 * Release our reference to this URB, the USB core will eventually free
 818	 * it entirely.
 819	 */
 820	usb_free_urb(urb);
 821
 822	return NETDEV_TX_OK;
 823
 824releasebuf:
 825	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 826
 827nobufmem:
 828	usb_free_urb(urb);
 829
 830nourbmem:
 831	return ret;
 832}
 833
 834static int esd_usb2_close(struct net_device *netdev)
 835{
 836	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 837	struct esd_usb2_msg msg;
 838	int i;
 839
 840	/* Disable all IDs (see esd_usb2_start()) */
 841	msg.msg.hdr.cmd = CMD_IDADD;
 842	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
 843	msg.msg.filter.net = priv->index;
 844	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
 845	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
 846		msg.msg.filter.mask[i] = 0;
 847	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
 848		dev_err(netdev->dev.parent, "sending idadd message failed\n");
 849
 850	/* set CAN controller to reset mode */
 851	msg.msg.hdr.len = 2;
 852	msg.msg.hdr.cmd = CMD_SETBAUD;
 853	msg.msg.setbaud.net = priv->index;
 854	msg.msg.setbaud.rsvd = 0;
 855	msg.msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
 856	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
 857		dev_err(netdev->dev.parent, "sending setbaud message failed\n");
 858
 859	priv->can.state = CAN_STATE_STOPPED;
 860
 861	netif_stop_queue(netdev);
 862
 863	close_candev(netdev);
 864
 865	priv->open_time = 0;
 866
 867	return 0;
 868}
 869
 870static const struct net_device_ops esd_usb2_netdev_ops = {
 871	.ndo_open = esd_usb2_open,
 872	.ndo_stop = esd_usb2_close,
 873	.ndo_start_xmit = esd_usb2_start_xmit,
 874};
 875
 876static struct can_bittiming_const esd_usb2_bittiming_const = {
 877	.name = "esd_usb2",
 878	.tseg1_min = ESD_USB2_TSEG1_MIN,
 879	.tseg1_max = ESD_USB2_TSEG1_MAX,
 880	.tseg2_min = ESD_USB2_TSEG2_MIN,
 881	.tseg2_max = ESD_USB2_TSEG2_MAX,
 882	.sjw_max = ESD_USB2_SJW_MAX,
 883	.brp_min = ESD_USB2_BRP_MIN,
 884	.brp_max = ESD_USB2_BRP_MAX,
 885	.brp_inc = ESD_USB2_BRP_INC,
 886};
 887
 888static int esd_usb2_set_bittiming(struct net_device *netdev)
 889{
 890	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 891	struct can_bittiming *bt = &priv->can.bittiming;
 892	struct esd_usb2_msg msg;
 893	u32 canbtr;
 894
 895	canbtr = ESD_USB2_UBR;
 896	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
 897	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
 898		<< ESD_USB2_SJW_SHIFT;
 899	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
 900		   & (ESD_USB2_TSEG1_MAX - 1))
 901		<< ESD_USB2_TSEG1_SHIFT;
 902	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
 903		<< ESD_USB2_TSEG2_SHIFT;
 904	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 905		canbtr |= ESD_USB2_3_SAMPLES;
 906
 907	msg.msg.hdr.len = 2;
 908	msg.msg.hdr.cmd = CMD_SETBAUD;
 909	msg.msg.setbaud.net = priv->index;
 910	msg.msg.setbaud.rsvd = 0;
 911	msg.msg.setbaud.baud = cpu_to_le32(canbtr);
 912
 913	dev_info(netdev->dev.parent, "setting BTR=%#x\n", canbtr);
 914
 915	return esd_usb2_send_msg(priv->usb2, &msg);
 916}
 917
 918static int esd_usb2_get_berr_counter(const struct net_device *netdev,
 919				     struct can_berr_counter *bec)
 920{
 921	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 922
 923	bec->txerr = priv->bec.txerr;
 924	bec->rxerr = priv->bec.rxerr;
 925
 926	return 0;
 927}
 928
 929static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
 930{
 931	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
 932
 933	if (!priv->open_time)
 934		return -EINVAL;
 935
 936	switch (mode) {
 937	case CAN_MODE_START:
 938		netif_wake_queue(netdev);
 939		break;
 940
 941	default:
 942		return -EOPNOTSUPP;
 943	}
 944
 945	return 0;
 946}
 947
 948static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
 949{
 950	struct esd_usb2 *dev = usb_get_intfdata(intf);
 951	struct net_device *netdev;
 952	struct esd_usb2_net_priv *priv;
 953	int err = 0;
 954	int i;
 955
 956	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
 957	if (!netdev) {
 958		dev_err(&intf->dev, "couldn't alloc candev\n");
 959		err = -ENOMEM;
 960		goto done;
 961	}
 962
 963	priv = netdev_priv(netdev);
 964
 965	init_usb_anchor(&priv->tx_submitted);
 966	atomic_set(&priv->active_tx_jobs, 0);
 967
 968	for (i = 0; i < MAX_TX_URBS; i++)
 969		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 970
 971	priv->usb2 = dev;
 972	priv->netdev = netdev;
 973	priv->index = index;
 974
 975	priv->can.state = CAN_STATE_STOPPED;
 976	priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
 977	priv->can.bittiming_const = &esd_usb2_bittiming_const;
 978	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
 979	priv->can.do_set_mode = esd_usb2_set_mode;
 980	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
 981	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 982
 983	netdev->flags |= IFF_ECHO; /* we support local echo */
 984
 985	netdev->netdev_ops = &esd_usb2_netdev_ops;
 986
 987	SET_NETDEV_DEV(netdev, &intf->dev);
 988
 989	err = register_candev(netdev);
 990	if (err) {
 991		dev_err(&intf->dev,
 992			"couldn't register CAN device: %d\n", err);
 993		free_candev(netdev);
 994		err = -ENOMEM;
 995		goto done;
 996	}
 997
 998	dev->nets[index] = priv;
 999	dev_info(netdev->dev.parent, "device %s registered\n", netdev->name);
1000
1001done:
1002	return err;
1003}
1004
1005/*
1006 * probe function for new USB2 devices
1007 *
1008 * check version information and number of available
1009 * CAN interfaces
1010 */
1011static int esd_usb2_probe(struct usb_interface *intf,
1012			 const struct usb_device_id *id)
1013{
1014	struct esd_usb2 *dev;
1015	struct esd_usb2_msg msg;
1016	int i, err;
1017
1018	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1019	if (!dev) {
1020		err = -ENOMEM;
1021		goto done;
1022	}
1023
1024	dev->udev = interface_to_usbdev(intf);
1025
1026	init_usb_anchor(&dev->rx_submitted);
1027
1028	usb_set_intfdata(intf, dev);
1029
1030	/* query number of CAN interfaces (nets) */
1031	msg.msg.hdr.cmd = CMD_VERSION;
1032	msg.msg.hdr.len = 2;
1033	msg.msg.version.rsvd = 0;
1034	msg.msg.version.flags = 0;
1035	msg.msg.version.drv_version = 0;
1036
1037	err = esd_usb2_send_msg(dev, &msg);
1038	if (err < 0) {
1039		dev_err(&intf->dev, "sending version message failed\n");
1040		goto free_dev;
1041	}
1042
1043	err = esd_usb2_wait_msg(dev, &msg);
1044	if (err < 0) {
1045		dev_err(&intf->dev, "no version message answer\n");
1046		goto free_dev;
1047	}
1048
1049	dev->net_count = (int)msg.msg.version_reply.nets;
1050	dev->version = le32_to_cpu(msg.msg.version_reply.version);
1051
1052	if (device_create_file(&intf->dev, &dev_attr_firmware))
1053		dev_err(&intf->dev,
1054			"Couldn't create device file for firmware\n");
1055
1056	if (device_create_file(&intf->dev, &dev_attr_hardware))
1057		dev_err(&intf->dev,
1058			"Couldn't create device file for hardware\n");
1059
1060	if (device_create_file(&intf->dev, &dev_attr_nets))
1061		dev_err(&intf->dev,
1062			"Couldn't create device file for nets\n");
1063
1064	/* do per device probing */
1065	for (i = 0; i < dev->net_count; i++)
1066		esd_usb2_probe_one_net(intf, i);
1067
1068	return 0;
1069
1070free_dev:
1071	kfree(dev);
1072done:
1073	return err;
1074}
1075
1076/*
1077 * called by the usb core when the device is removed from the system
1078 */
1079static void esd_usb2_disconnect(struct usb_interface *intf)
1080{
1081	struct esd_usb2 *dev = usb_get_intfdata(intf);
1082	struct net_device *netdev;
1083	int i;
1084
1085	device_remove_file(&intf->dev, &dev_attr_firmware);
1086	device_remove_file(&intf->dev, &dev_attr_hardware);
1087	device_remove_file(&intf->dev, &dev_attr_nets);
1088
1089	usb_set_intfdata(intf, NULL);
1090
1091	if (dev) {
1092		for (i = 0; i < dev->net_count; i++) {
1093			if (dev->nets[i]) {
1094				netdev = dev->nets[i]->netdev;
1095				unregister_netdev(netdev);
1096				free_candev(netdev);
1097			}
1098		}
1099		unlink_all_urbs(dev);
1100	}
1101}
1102
1103/* usb specific object needed to register this driver with the usb subsystem */
1104static struct usb_driver esd_usb2_driver = {
1105	.name = "esd_usb2",
1106	.probe = esd_usb2_probe,
1107	.disconnect = esd_usb2_disconnect,
1108	.id_table = esd_usb2_table,
1109};
1110
1111static int __init esd_usb2_init(void)
1112{
1113	int err;
1114
1115	/* register this driver with the USB subsystem */
1116	err = usb_register(&esd_usb2_driver);
1117
1118	if (err) {
1119		err("usb_register failed. Error number %d\n", err);
1120		return err;
1121	}
1122
1123	return 0;
1124}
1125module_init(esd_usb2_init);
1126
1127static void __exit esd_usb2_exit(void)
1128{
1129	/* deregister this driver with the USB subsystem */
1130	usb_deregister(&esd_usb2_driver);
1131}
1132module_exit(esd_usb2_exit);