Linux Audio

Check our new training course

Loading...
Note: File does not exist in v4.6.
   1// SPDX-License-Identifier: GPL-2.0
   2/* Fintek F81604 USB-to-2CAN controller driver.
   3 *
   4 * Copyright (C) 2023 Ji-Ze Hong (Peter Hong) <peter_hong@fintek.com.tw>
   5 */
   6#include <linux/bitfield.h>
   7#include <linux/netdevice.h>
   8#include <linux/units.h>
   9#include <linux/usb.h>
  10
  11#include <linux/can.h>
  12#include <linux/can/dev.h>
  13#include <linux/can/error.h>
  14#include <linux/can/platform/sja1000.h>
  15
  16#include <asm-generic/unaligned.h>
  17
  18/* vendor and product id */
  19#define F81604_VENDOR_ID 0x2c42
  20#define F81604_PRODUCT_ID 0x1709
  21#define F81604_CAN_CLOCK (12 * MEGA)
  22#define F81604_MAX_DEV 2
  23#define F81604_SET_DEVICE_RETRY 10
  24
  25#define F81604_USB_TIMEOUT 2000
  26#define F81604_SET_GET_REGISTER 0xA0
  27#define F81604_PORT_OFFSET 0x1000
  28#define F81604_MAX_RX_URBS 4
  29
  30#define F81604_CMD_DATA 0x00
  31
  32#define F81604_DLC_LEN_MASK GENMASK(3, 0)
  33#define F81604_DLC_EFF_BIT BIT(7)
  34#define F81604_DLC_RTR_BIT BIT(6)
  35
  36#define F81604_SFF_SHIFT 5
  37#define F81604_EFF_SHIFT 3
  38
  39#define F81604_BRP_MASK GENMASK(5, 0)
  40#define F81604_SJW_MASK GENMASK(7, 6)
  41
  42#define F81604_SEG1_MASK GENMASK(3, 0)
  43#define F81604_SEG2_MASK GENMASK(6, 4)
  44
  45#define F81604_CLEAR_ALC 0
  46#define F81604_CLEAR_ECC 1
  47#define F81604_CLEAR_OVERRUN 2
  48
  49/* device setting */
  50#define F81604_CTRL_MODE_REG 0x80
  51#define F81604_TX_ONESHOT (0x03 << 3)
  52#define F81604_TX_NORMAL (0x01 << 3)
  53#define F81604_RX_AUTO_RELEASE_BUF BIT(1)
  54#define F81604_INT_WHEN_CHANGE BIT(0)
  55
  56#define F81604_TERMINATOR_REG 0x105
  57#define F81604_CAN0_TERM BIT(2)
  58#define F81604_CAN1_TERM BIT(3)
  59
  60#define F81604_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
  61#define F81604_TERMINATION_ENABLED 120
  62
  63/* SJA1000 registers - manual section 6.4 (Pelican Mode) */
  64#define F81604_SJA1000_MOD 0x00
  65#define F81604_SJA1000_CMR 0x01
  66#define F81604_SJA1000_IR 0x03
  67#define F81604_SJA1000_IER 0x04
  68#define F81604_SJA1000_ALC 0x0B
  69#define F81604_SJA1000_ECC 0x0C
  70#define F81604_SJA1000_RXERR 0x0E
  71#define F81604_SJA1000_TXERR 0x0F
  72#define F81604_SJA1000_ACCC0 0x10
  73#define F81604_SJA1000_ACCM0 0x14
  74#define F81604_MAX_FILTER_CNT 4
  75
  76/* Common registers - manual section 6.5 */
  77#define F81604_SJA1000_BTR0 0x06
  78#define F81604_SJA1000_BTR1 0x07
  79#define F81604_SJA1000_BTR1_SAMPLE_TRIPLE BIT(7)
  80#define F81604_SJA1000_OCR 0x08
  81#define F81604_SJA1000_CDR 0x1F
  82
  83/* mode register */
  84#define F81604_SJA1000_MOD_RM 0x01
  85#define F81604_SJA1000_MOD_LOM 0x02
  86#define F81604_SJA1000_MOD_STM 0x04
  87
  88/* commands */
  89#define F81604_SJA1000_CMD_CDO 0x08
  90
  91/* interrupt sources */
  92#define F81604_SJA1000_IRQ_BEI 0x80
  93#define F81604_SJA1000_IRQ_ALI 0x40
  94#define F81604_SJA1000_IRQ_EPI 0x20
  95#define F81604_SJA1000_IRQ_DOI 0x08
  96#define F81604_SJA1000_IRQ_EI 0x04
  97#define F81604_SJA1000_IRQ_TI 0x02
  98#define F81604_SJA1000_IRQ_RI 0x01
  99#define F81604_SJA1000_IRQ_ALL 0xFF
 100#define F81604_SJA1000_IRQ_OFF 0x00
 101
 102/* status register content */
 103#define F81604_SJA1000_SR_BS 0x80
 104#define F81604_SJA1000_SR_ES 0x40
 105#define F81604_SJA1000_SR_TCS 0x08
 106
 107/* ECC register */
 108#define F81604_SJA1000_ECC_SEG 0x1F
 109#define F81604_SJA1000_ECC_DIR 0x20
 110#define F81604_SJA1000_ECC_BIT 0x00
 111#define F81604_SJA1000_ECC_FORM 0x40
 112#define F81604_SJA1000_ECC_STUFF 0x80
 113#define F81604_SJA1000_ECC_MASK 0xc0
 114
 115/* ALC register */
 116#define F81604_SJA1000_ALC_MASK 0x1f
 117
 118/* table of devices that work with this driver */
 119static const struct usb_device_id f81604_table[] = {
 120	{ USB_DEVICE(F81604_VENDOR_ID, F81604_PRODUCT_ID) },
 121	{} /* Terminating entry */
 122};
 123
 124MODULE_DEVICE_TABLE(usb, f81604_table);
 125
 126static const struct ethtool_ops f81604_ethtool_ops = {
 127	.get_ts_info = ethtool_op_get_ts_info,
 128};
 129
 130static const u16 f81604_termination[] = { F81604_TERMINATION_DISABLED,
 131					  F81604_TERMINATION_ENABLED };
 132
 133struct f81604_priv {
 134	struct net_device *netdev[F81604_MAX_DEV];
 135};
 136
 137struct f81604_port_priv {
 138	struct can_priv can;
 139	struct net_device *netdev;
 140	struct sk_buff *echo_skb;
 141
 142	unsigned long clear_flags;
 143	struct work_struct clear_reg_work;
 144
 145	struct usb_device *dev;
 146	struct usb_interface *intf;
 147
 148	struct usb_anchor urbs_anchor;
 149};
 150
 151/* Interrupt endpoint data format:
 152 *	Byte 0: Status register.
 153 *	Byte 1: Interrupt register.
 154 *	Byte 2: Interrupt enable register.
 155 *	Byte 3: Arbitration lost capture(ALC) register.
 156 *	Byte 4: Error code capture(ECC) register.
 157 *	Byte 5: Error warning limit register.
 158 *	Byte 6: RX error counter register.
 159 *	Byte 7: TX error counter register.
 160 *	Byte 8: Reserved.
 161 */
 162struct f81604_int_data {
 163	u8 sr;
 164	u8 isrc;
 165	u8 ier;
 166	u8 alc;
 167	u8 ecc;
 168	u8 ewlr;
 169	u8 rxerr;
 170	u8 txerr;
 171	u8 val;
 172} __packed __aligned(4);
 173
 174struct f81604_sff {
 175	__be16 id;
 176	u8 data[CAN_MAX_DLEN];
 177} __packed __aligned(2);
 178
 179struct f81604_eff {
 180	__be32 id;
 181	u8 data[CAN_MAX_DLEN];
 182} __packed __aligned(2);
 183
 184struct f81604_can_frame {
 185	u8 cmd;
 186
 187	/* According for F81604 DLC define:
 188	 *	bit 3~0: data length (0~8)
 189	 *	bit6: is RTR flag.
 190	 *	bit7: is EFF frame.
 191	 */
 192	u8 dlc;
 193
 194	union {
 195		struct f81604_sff sff;
 196		struct f81604_eff eff;
 197	};
 198} __packed __aligned(2);
 199
 200static const u8 bulk_in_addr[F81604_MAX_DEV] = { 2, 4 };
 201static const u8 bulk_out_addr[F81604_MAX_DEV] = { 1, 3 };
 202static const u8 int_in_addr[F81604_MAX_DEV] = { 1, 3 };
 203
 204static int f81604_write(struct usb_device *dev, u16 reg, u8 data)
 205{
 206	int ret;
 207
 208	ret = usb_control_msg_send(dev, 0, F81604_SET_GET_REGISTER,
 209				   USB_TYPE_VENDOR | USB_DIR_OUT, 0, reg,
 210				   &data, sizeof(data), F81604_USB_TIMEOUT,
 211				   GFP_KERNEL);
 212	if (ret)
 213		dev_err(&dev->dev, "%s: reg: %x data: %x failed: %pe\n",
 214			__func__, reg, data, ERR_PTR(ret));
 215
 216	return ret;
 217}
 218
 219static int f81604_read(struct usb_device *dev, u16 reg, u8 *data)
 220{
 221	int ret;
 222
 223	ret = usb_control_msg_recv(dev, 0, F81604_SET_GET_REGISTER,
 224				   USB_TYPE_VENDOR | USB_DIR_IN, 0, reg, data,
 225				   sizeof(*data), F81604_USB_TIMEOUT,
 226				   GFP_KERNEL);
 227
 228	if (ret < 0)
 229		dev_err(&dev->dev, "%s: reg: %x failed: %pe\n", __func__, reg,
 230			ERR_PTR(ret));
 231
 232	return ret;
 233}
 234
 235static int f81604_update_bits(struct usb_device *dev, u16 reg, u8 mask,
 236			      u8 data)
 237{
 238	int ret;
 239	u8 tmp;
 240
 241	ret = f81604_read(dev, reg, &tmp);
 242	if (ret)
 243		return ret;
 244
 245	tmp &= ~mask;
 246	tmp |= (mask & data);
 247
 248	return f81604_write(dev, reg, tmp);
 249}
 250
 251static int f81604_sja1000_write(struct f81604_port_priv *priv, u16 reg,
 252				u8 data)
 253{
 254	int port = priv->netdev->dev_port;
 255	int real_reg;
 256
 257	real_reg = reg + F81604_PORT_OFFSET * port + F81604_PORT_OFFSET;
 258	return f81604_write(priv->dev, real_reg, data);
 259}
 260
 261static int f81604_sja1000_read(struct f81604_port_priv *priv, u16 reg,
 262			       u8 *data)
 263{
 264	int port = priv->netdev->dev_port;
 265	int real_reg;
 266
 267	real_reg = reg + F81604_PORT_OFFSET * port + F81604_PORT_OFFSET;
 268	return f81604_read(priv->dev, real_reg, data);
 269}
 270
 271static int f81604_set_reset_mode(struct f81604_port_priv *priv)
 272{
 273	int ret, i;
 274	u8 tmp;
 275
 276	/* disable interrupts */
 277	ret = f81604_sja1000_write(priv, F81604_SJA1000_IER,
 278				   F81604_SJA1000_IRQ_OFF);
 279	if (ret)
 280		return ret;
 281
 282	for (i = 0; i < F81604_SET_DEVICE_RETRY; i++) {
 283		ret = f81604_sja1000_read(priv, F81604_SJA1000_MOD, &tmp);
 284		if (ret)
 285			return ret;
 286
 287		/* check reset bit */
 288		if (tmp & F81604_SJA1000_MOD_RM) {
 289			priv->can.state = CAN_STATE_STOPPED;
 290			return 0;
 291		}
 292
 293		/* reset chip */
 294		ret = f81604_sja1000_write(priv, F81604_SJA1000_MOD,
 295					   F81604_SJA1000_MOD_RM);
 296		if (ret)
 297			return ret;
 298	}
 299
 300	return -EPERM;
 301}
 302
 303static int f81604_set_normal_mode(struct f81604_port_priv *priv)
 304{
 305	u8 tmp, ier = 0;
 306	u8 mod_reg = 0;
 307	int ret, i;
 308
 309	for (i = 0; i < F81604_SET_DEVICE_RETRY; i++) {
 310		ret = f81604_sja1000_read(priv, F81604_SJA1000_MOD, &tmp);
 311		if (ret)
 312			return ret;
 313
 314		/* check reset bit */
 315		if ((tmp & F81604_SJA1000_MOD_RM) == 0) {
 316			priv->can.state = CAN_STATE_ERROR_ACTIVE;
 317			/* enable interrupts, RI handled by bulk-in */
 318			ier = F81604_SJA1000_IRQ_ALL & ~F81604_SJA1000_IRQ_RI;
 319			if (!(priv->can.ctrlmode &
 320			      CAN_CTRLMODE_BERR_REPORTING))
 321				ier &= ~F81604_SJA1000_IRQ_BEI;
 322
 323			return f81604_sja1000_write(priv, F81604_SJA1000_IER,
 324						    ier);
 325		}
 326
 327		/* set chip to normal mode */
 328		if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 329			mod_reg |= F81604_SJA1000_MOD_LOM;
 330		if (priv->can.ctrlmode & CAN_CTRLMODE_PRESUME_ACK)
 331			mod_reg |= F81604_SJA1000_MOD_STM;
 332
 333		ret = f81604_sja1000_write(priv, F81604_SJA1000_MOD, mod_reg);
 334		if (ret)
 335			return ret;
 336	}
 337
 338	return -EPERM;
 339}
 340
 341static int f81604_chipset_init(struct f81604_port_priv *priv)
 342{
 343	int i, ret;
 344
 345	/* set clock divider and output control register */
 346	ret = f81604_sja1000_write(priv, F81604_SJA1000_CDR,
 347				   CDR_CBP | CDR_PELICAN);
 348	if (ret)
 349		return ret;
 350
 351	/* set acceptance filter (accept all) */
 352	for (i = 0; i < F81604_MAX_FILTER_CNT; ++i) {
 353		ret = f81604_sja1000_write(priv, F81604_SJA1000_ACCC0 + i, 0);
 354		if (ret)
 355			return ret;
 356	}
 357
 358	for (i = 0; i < F81604_MAX_FILTER_CNT; ++i) {
 359		ret = f81604_sja1000_write(priv, F81604_SJA1000_ACCM0 + i,
 360					   0xFF);
 361		if (ret)
 362			return ret;
 363	}
 364
 365	return f81604_sja1000_write(priv, F81604_SJA1000_OCR,
 366				    OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL |
 367					    OCR_MODE_NORMAL);
 368}
 369
 370static void f81604_process_rx_packet(struct net_device *netdev,
 371				     struct f81604_can_frame *frame)
 372{
 373	struct net_device_stats *stats = &netdev->stats;
 374	struct can_frame *cf;
 375	struct sk_buff *skb;
 376
 377	if (frame->cmd != F81604_CMD_DATA)
 378		return;
 379
 380	skb = alloc_can_skb(netdev, &cf);
 381	if (!skb) {
 382		stats->rx_dropped++;
 383		return;
 384	}
 385
 386	cf->len = can_cc_dlc2len(frame->dlc & F81604_DLC_LEN_MASK);
 387
 388	if (frame->dlc & F81604_DLC_EFF_BIT) {
 389		cf->can_id = get_unaligned_be32(&frame->eff.id) >>
 390			     F81604_EFF_SHIFT;
 391		cf->can_id |= CAN_EFF_FLAG;
 392
 393		if (!(frame->dlc & F81604_DLC_RTR_BIT))
 394			memcpy(cf->data, frame->eff.data, cf->len);
 395	} else {
 396		cf->can_id = get_unaligned_be16(&frame->sff.id) >>
 397			     F81604_SFF_SHIFT;
 398
 399		if (!(frame->dlc & F81604_DLC_RTR_BIT))
 400			memcpy(cf->data, frame->sff.data, cf->len);
 401	}
 402
 403	if (frame->dlc & F81604_DLC_RTR_BIT)
 404		cf->can_id |= CAN_RTR_FLAG;
 405	else
 406		stats->rx_bytes += cf->len;
 407
 408	stats->rx_packets++;
 409	netif_rx(skb);
 410}
 411
 412static void f81604_read_bulk_callback(struct urb *urb)
 413{
 414	struct f81604_can_frame *frame = urb->transfer_buffer;
 415	struct net_device *netdev = urb->context;
 416	int ret;
 417
 418	if (!netif_device_present(netdev))
 419		return;
 420
 421	if (urb->status)
 422		netdev_info(netdev, "%s: URB aborted %pe\n", __func__,
 423			    ERR_PTR(urb->status));
 424
 425	switch (urb->status) {
 426	case 0: /* success */
 427		break;
 428
 429	case -ENOENT:
 430	case -EPIPE:
 431	case -EPROTO:
 432	case -ESHUTDOWN:
 433		return;
 434
 435	default:
 436		goto resubmit_urb;
 437	}
 438
 439	if (urb->actual_length != sizeof(*frame)) {
 440		netdev_warn(netdev, "URB length %u not equal to %zu\n",
 441			    urb->actual_length, sizeof(*frame));
 442		goto resubmit_urb;
 443	}
 444
 445	f81604_process_rx_packet(netdev, frame);
 446
 447resubmit_urb:
 448	ret = usb_submit_urb(urb, GFP_ATOMIC);
 449	if (ret == -ENODEV)
 450		netif_device_detach(netdev);
 451	else if (ret)
 452		netdev_err(netdev,
 453			   "%s: failed to resubmit read bulk urb: %pe\n",
 454			   __func__, ERR_PTR(ret));
 455}
 456
 457static void f81604_handle_tx(struct f81604_port_priv *priv,
 458			     struct f81604_int_data *data)
 459{
 460	struct net_device *netdev = priv->netdev;
 461	struct net_device_stats *stats = &netdev->stats;
 462
 463	/* transmission buffer released */
 464	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
 465	    !(data->sr & F81604_SJA1000_SR_TCS)) {
 466		stats->tx_errors++;
 467		can_free_echo_skb(netdev, 0, NULL);
 468	} else {
 469		/* transmission complete */
 470		stats->tx_bytes += can_get_echo_skb(netdev, 0, NULL);
 471		stats->tx_packets++;
 472	}
 473
 474	netif_wake_queue(netdev);
 475}
 476
 477static void f81604_handle_can_bus_errors(struct f81604_port_priv *priv,
 478					 struct f81604_int_data *data)
 479{
 480	enum can_state can_state = priv->can.state;
 481	struct net_device *netdev = priv->netdev;
 482	struct net_device_stats *stats = &netdev->stats;
 483	struct can_frame *cf;
 484	struct sk_buff *skb;
 485
 486	/* Note: ALC/ECC will not auto clear by read here, must be cleared by
 487	 * read register (via clear_reg_work).
 488	 */
 489
 490	skb = alloc_can_err_skb(netdev, &cf);
 491	if (skb) {
 492		cf->can_id |= CAN_ERR_CNT;
 493		cf->data[6] = data->txerr;
 494		cf->data[7] = data->rxerr;
 495	}
 496
 497	if (data->isrc & F81604_SJA1000_IRQ_DOI) {
 498		/* data overrun interrupt */
 499		netdev_dbg(netdev, "data overrun interrupt\n");
 500
 501		if (skb) {
 502			cf->can_id |= CAN_ERR_CRTL;
 503			cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 504		}
 505
 506		stats->rx_over_errors++;
 507		stats->rx_errors++;
 508
 509		set_bit(F81604_CLEAR_OVERRUN, &priv->clear_flags);
 510	}
 511
 512	if (data->isrc & F81604_SJA1000_IRQ_EI) {
 513		/* error warning interrupt */
 514		netdev_dbg(netdev, "error warning interrupt\n");
 515
 516		if (data->sr & F81604_SJA1000_SR_BS)
 517			can_state = CAN_STATE_BUS_OFF;
 518		else if (data->sr & F81604_SJA1000_SR_ES)
 519			can_state = CAN_STATE_ERROR_WARNING;
 520		else
 521			can_state = CAN_STATE_ERROR_ACTIVE;
 522	}
 523
 524	if (data->isrc & F81604_SJA1000_IRQ_BEI) {
 525		/* bus error interrupt */
 526		netdev_dbg(netdev, "bus error interrupt\n");
 527
 528		priv->can.can_stats.bus_error++;
 529		stats->rx_errors++;
 530
 531		if (skb) {
 532			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 533
 534			/* set error type */
 535			switch (data->ecc & F81604_SJA1000_ECC_MASK) {
 536			case F81604_SJA1000_ECC_BIT:
 537				cf->data[2] |= CAN_ERR_PROT_BIT;
 538				break;
 539			case F81604_SJA1000_ECC_FORM:
 540				cf->data[2] |= CAN_ERR_PROT_FORM;
 541				break;
 542			case F81604_SJA1000_ECC_STUFF:
 543				cf->data[2] |= CAN_ERR_PROT_STUFF;
 544				break;
 545			default:
 546				break;
 547			}
 548
 549			/* set error location */
 550			cf->data[3] = data->ecc & F81604_SJA1000_ECC_SEG;
 551
 552			/* Error occurred during transmission? */
 553			if ((data->ecc & F81604_SJA1000_ECC_DIR) == 0)
 554				cf->data[2] |= CAN_ERR_PROT_TX;
 555		}
 556
 557		set_bit(F81604_CLEAR_ECC, &priv->clear_flags);
 558	}
 559
 560	if (data->isrc & F81604_SJA1000_IRQ_EPI) {
 561		if (can_state == CAN_STATE_ERROR_PASSIVE)
 562			can_state = CAN_STATE_ERROR_WARNING;
 563		else
 564			can_state = CAN_STATE_ERROR_PASSIVE;
 565
 566		/* error passive interrupt */
 567		netdev_dbg(netdev, "error passive interrupt: %d\n", can_state);
 568	}
 569
 570	if (data->isrc & F81604_SJA1000_IRQ_ALI) {
 571		/* arbitration lost interrupt */
 572		netdev_dbg(netdev, "arbitration lost interrupt\n");
 573
 574		priv->can.can_stats.arbitration_lost++;
 575
 576		if (skb) {
 577			cf->can_id |= CAN_ERR_LOSTARB;
 578			cf->data[0] = data->alc & F81604_SJA1000_ALC_MASK;
 579		}
 580
 581		set_bit(F81604_CLEAR_ALC, &priv->clear_flags);
 582	}
 583
 584	if (can_state != priv->can.state) {
 585		enum can_state tx_state, rx_state;
 586
 587		tx_state = data->txerr >= data->rxerr ? can_state : 0;
 588		rx_state = data->txerr <= data->rxerr ? can_state : 0;
 589
 590		can_change_state(netdev, cf, tx_state, rx_state);
 591
 592		if (can_state == CAN_STATE_BUS_OFF)
 593			can_bus_off(netdev);
 594	}
 595
 596	if (priv->clear_flags)
 597		schedule_work(&priv->clear_reg_work);
 598
 599	if (skb)
 600		netif_rx(skb);
 601}
 602
 603static void f81604_read_int_callback(struct urb *urb)
 604{
 605	struct f81604_int_data *data = urb->transfer_buffer;
 606	struct net_device *netdev = urb->context;
 607	struct f81604_port_priv *priv;
 608	int ret;
 609
 610	priv = netdev_priv(netdev);
 611
 612	if (!netif_device_present(netdev))
 613		return;
 614
 615	if (urb->status)
 616		netdev_info(netdev, "%s: Int URB aborted: %pe\n", __func__,
 617			    ERR_PTR(urb->status));
 618
 619	switch (urb->status) {
 620	case 0: /* success */
 621		break;
 622
 623	case -ENOENT:
 624	case -EPIPE:
 625	case -EPROTO:
 626	case -ESHUTDOWN:
 627		return;
 628
 629	default:
 630		goto resubmit_urb;
 631	}
 632
 633	/* handle Errors */
 634	if (data->isrc & (F81604_SJA1000_IRQ_DOI | F81604_SJA1000_IRQ_EI |
 635			  F81604_SJA1000_IRQ_BEI | F81604_SJA1000_IRQ_EPI |
 636			  F81604_SJA1000_IRQ_ALI))
 637		f81604_handle_can_bus_errors(priv, data);
 638
 639	/* handle TX */
 640	if (priv->can.state != CAN_STATE_BUS_OFF &&
 641	    (data->isrc & F81604_SJA1000_IRQ_TI))
 642		f81604_handle_tx(priv, data);
 643
 644resubmit_urb:
 645	ret = usb_submit_urb(urb, GFP_ATOMIC);
 646	if (ret == -ENODEV)
 647		netif_device_detach(netdev);
 648	else if (ret)
 649		netdev_err(netdev, "%s: failed to resubmit int urb: %pe\n",
 650			   __func__, ERR_PTR(ret));
 651}
 652
 653static void f81604_unregister_urbs(struct f81604_port_priv *priv)
 654{
 655	usb_kill_anchored_urbs(&priv->urbs_anchor);
 656}
 657
 658static int f81604_register_urbs(struct f81604_port_priv *priv)
 659{
 660	struct net_device *netdev = priv->netdev;
 661	struct f81604_int_data *int_data;
 662	int id = netdev->dev_port;
 663	struct urb *int_urb;
 664	int rx_urb_cnt;
 665	int ret;
 666
 667	for (rx_urb_cnt = 0; rx_urb_cnt < F81604_MAX_RX_URBS; ++rx_urb_cnt) {
 668		struct f81604_can_frame *frame;
 669		struct urb *rx_urb;
 670
 671		rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 672		if (!rx_urb) {
 673			ret = -ENOMEM;
 674			break;
 675		}
 676
 677		frame = kmalloc(sizeof(*frame), GFP_KERNEL);
 678		if (!frame) {
 679			usb_free_urb(rx_urb);
 680			ret = -ENOMEM;
 681			break;
 682		}
 683
 684		usb_fill_bulk_urb(rx_urb, priv->dev,
 685				  usb_rcvbulkpipe(priv->dev, bulk_in_addr[id]),
 686				  frame, sizeof(*frame),
 687				  f81604_read_bulk_callback, netdev);
 688
 689		rx_urb->transfer_flags |= URB_FREE_BUFFER;
 690		usb_anchor_urb(rx_urb, &priv->urbs_anchor);
 691
 692		ret = usb_submit_urb(rx_urb, GFP_KERNEL);
 693		if (ret) {
 694			usb_unanchor_urb(rx_urb);
 695			usb_free_urb(rx_urb);
 696			break;
 697		}
 698
 699		/* Drop reference, USB core will take care of freeing it */
 700		usb_free_urb(rx_urb);
 701	}
 702
 703	if (rx_urb_cnt == 0) {
 704		netdev_warn(netdev, "%s: submit rx urb failed: %pe\n",
 705			    __func__, ERR_PTR(ret));
 706
 707		goto error;
 708	}
 709
 710	int_urb = usb_alloc_urb(0, GFP_KERNEL);
 711	if (!int_urb) {
 712		ret = -ENOMEM;
 713		goto error;
 714	}
 715
 716	int_data = kmalloc(sizeof(*int_data), GFP_KERNEL);
 717	if (!int_data) {
 718		usb_free_urb(int_urb);
 719		ret = -ENOMEM;
 720		goto error;
 721	}
 722
 723	usb_fill_int_urb(int_urb, priv->dev,
 724			 usb_rcvintpipe(priv->dev, int_in_addr[id]), int_data,
 725			 sizeof(*int_data), f81604_read_int_callback, netdev,
 726			 1);
 727
 728	int_urb->transfer_flags |= URB_FREE_BUFFER;
 729	usb_anchor_urb(int_urb, &priv->urbs_anchor);
 730
 731	ret = usb_submit_urb(int_urb, GFP_KERNEL);
 732	if (ret) {
 733		usb_unanchor_urb(int_urb);
 734		usb_free_urb(int_urb);
 735
 736		netdev_warn(netdev, "%s: submit int urb failed: %pe\n",
 737			    __func__, ERR_PTR(ret));
 738		goto error;
 739	}
 740
 741	/* Drop reference, USB core will take care of freeing it */
 742	usb_free_urb(int_urb);
 743
 744	return 0;
 745
 746error:
 747	f81604_unregister_urbs(priv);
 748	return ret;
 749}
 750
 751static int f81604_start(struct net_device *netdev)
 752{
 753	struct f81604_port_priv *priv = netdev_priv(netdev);
 754	int ret;
 755	u8 mode;
 756	u8 tmp;
 757
 758	mode = F81604_RX_AUTO_RELEASE_BUF | F81604_INT_WHEN_CHANGE;
 759
 760	/* Set TR/AT mode */
 761	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 762		mode |= F81604_TX_ONESHOT;
 763	else
 764		mode |= F81604_TX_NORMAL;
 765
 766	ret = f81604_sja1000_write(priv, F81604_CTRL_MODE_REG, mode);
 767	if (ret)
 768		return ret;
 769
 770	/* set reset mode */
 771	ret = f81604_set_reset_mode(priv);
 772	if (ret)
 773		return ret;
 774
 775	ret = f81604_chipset_init(priv);
 776	if (ret)
 777		return ret;
 778
 779	/* Clear error counters and error code capture */
 780	ret = f81604_sja1000_write(priv, F81604_SJA1000_TXERR, 0);
 781	if (ret)
 782		return ret;
 783
 784	ret = f81604_sja1000_write(priv, F81604_SJA1000_RXERR, 0);
 785	if (ret)
 786		return ret;
 787
 788	/* Read clear for ECC/ALC/IR register */
 789	ret = f81604_sja1000_read(priv, F81604_SJA1000_ECC, &tmp);
 790	if (ret)
 791		return ret;
 792
 793	ret = f81604_sja1000_read(priv, F81604_SJA1000_ALC, &tmp);
 794	if (ret)
 795		return ret;
 796
 797	ret = f81604_sja1000_read(priv, F81604_SJA1000_IR, &tmp);
 798	if (ret)
 799		return ret;
 800
 801	ret = f81604_register_urbs(priv);
 802	if (ret)
 803		return ret;
 804
 805	ret = f81604_set_normal_mode(priv);
 806	if (ret) {
 807		f81604_unregister_urbs(priv);
 808		return ret;
 809	}
 810
 811	return 0;
 812}
 813
 814static int f81604_set_bittiming(struct net_device *dev)
 815{
 816	struct f81604_port_priv *priv = netdev_priv(dev);
 817	struct can_bittiming *bt = &priv->can.bittiming;
 818	u8 btr0, btr1;
 819	int ret;
 820
 821	btr0 = FIELD_PREP(F81604_BRP_MASK, bt->brp - 1) |
 822	       FIELD_PREP(F81604_SJW_MASK, bt->sjw - 1);
 823
 824	btr1 = FIELD_PREP(F81604_SEG1_MASK,
 825			  bt->prop_seg + bt->phase_seg1 - 1) |
 826	       FIELD_PREP(F81604_SEG2_MASK, bt->phase_seg2 - 1);
 827
 828	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 829		btr1 |= F81604_SJA1000_BTR1_SAMPLE_TRIPLE;
 830
 831	ret = f81604_sja1000_write(priv, F81604_SJA1000_BTR0, btr0);
 832	if (ret) {
 833		netdev_warn(dev, "%s: Set BTR0 failed: %pe\n", __func__,
 834			    ERR_PTR(ret));
 835		return ret;
 836	}
 837
 838	ret = f81604_sja1000_write(priv, F81604_SJA1000_BTR1, btr1);
 839	if (ret) {
 840		netdev_warn(dev, "%s: Set BTR1 failed: %pe\n", __func__,
 841			    ERR_PTR(ret));
 842		return ret;
 843	}
 844
 845	return 0;
 846}
 847
 848static int f81604_set_mode(struct net_device *netdev, enum can_mode mode)
 849{
 850	int ret;
 851
 852	switch (mode) {
 853	case CAN_MODE_START:
 854		ret = f81604_start(netdev);
 855		if (!ret && netif_queue_stopped(netdev))
 856			netif_wake_queue(netdev);
 857		break;
 858
 859	default:
 860		ret = -EOPNOTSUPP;
 861	}
 862
 863	return ret;
 864}
 865
 866static void f81604_write_bulk_callback(struct urb *urb)
 867{
 868	struct net_device *netdev = urb->context;
 869
 870	if (!netif_device_present(netdev))
 871		return;
 872
 873	if (urb->status)
 874		netdev_info(netdev, "%s: Tx URB error: %pe\n", __func__,
 875			    ERR_PTR(urb->status));
 876}
 877
 878static void f81604_clear_reg_work(struct work_struct *work)
 879{
 880	struct f81604_port_priv *priv;
 881	u8 tmp;
 882
 883	priv = container_of(work, struct f81604_port_priv, clear_reg_work);
 884
 885	/* dummy read for clear Arbitration lost capture(ALC) register. */
 886	if (test_and_clear_bit(F81604_CLEAR_ALC, &priv->clear_flags))
 887		f81604_sja1000_read(priv, F81604_SJA1000_ALC, &tmp);
 888
 889	/* dummy read for clear Error code capture(ECC) register. */
 890	if (test_and_clear_bit(F81604_CLEAR_ECC, &priv->clear_flags))
 891		f81604_sja1000_read(priv, F81604_SJA1000_ECC, &tmp);
 892
 893	/* dummy write for clear data overrun flag. */
 894	if (test_and_clear_bit(F81604_CLEAR_OVERRUN, &priv->clear_flags))
 895		f81604_sja1000_write(priv, F81604_SJA1000_CMR,
 896				     F81604_SJA1000_CMD_CDO);
 897}
 898
 899static netdev_tx_t f81604_start_xmit(struct sk_buff *skb,
 900				     struct net_device *netdev)
 901{
 902	struct can_frame *cf = (struct can_frame *)skb->data;
 903	struct f81604_port_priv *priv = netdev_priv(netdev);
 904	struct net_device_stats *stats = &netdev->stats;
 905	struct f81604_can_frame *frame;
 906	struct urb *write_urb;
 907	int ret;
 908
 909	if (can_dev_dropped_skb(netdev, skb))
 910		return NETDEV_TX_OK;
 911
 912	netif_stop_queue(netdev);
 913
 914	write_urb = usb_alloc_urb(0, GFP_ATOMIC);
 915	if (!write_urb)
 916		goto nomem_urb;
 917
 918	frame = kzalloc(sizeof(*frame), GFP_ATOMIC);
 919	if (!frame)
 920		goto nomem_buf;
 921
 922	usb_fill_bulk_urb(write_urb, priv->dev,
 923			  usb_sndbulkpipe(priv->dev,
 924					  bulk_out_addr[netdev->dev_port]),
 925			  frame, sizeof(*frame), f81604_write_bulk_callback,
 926			  priv->netdev);
 927
 928	write_urb->transfer_flags |= URB_FREE_BUFFER;
 929
 930	frame->cmd = F81604_CMD_DATA;
 931	frame->dlc = cf->len;
 932
 933	if (cf->can_id & CAN_RTR_FLAG)
 934		frame->dlc |= F81604_DLC_RTR_BIT;
 935
 936	if (cf->can_id & CAN_EFF_FLAG) {
 937		u32 id = (cf->can_id & CAN_EFF_MASK) << F81604_EFF_SHIFT;
 938
 939		put_unaligned_be32(id, &frame->eff.id);
 940
 941		frame->dlc |= F81604_DLC_EFF_BIT;
 942
 943		if (!(cf->can_id & CAN_RTR_FLAG))
 944			memcpy(&frame->eff.data, cf->data, cf->len);
 945	} else {
 946		u32 id = (cf->can_id & CAN_SFF_MASK) << F81604_SFF_SHIFT;
 947
 948		put_unaligned_be16(id, &frame->sff.id);
 949
 950		if (!(cf->can_id & CAN_RTR_FLAG))
 951			memcpy(&frame->sff.data, cf->data, cf->len);
 952	}
 953
 954	can_put_echo_skb(skb, netdev, 0, 0);
 955
 956	ret = usb_submit_urb(write_urb, GFP_ATOMIC);
 957	if (ret) {
 958		netdev_err(netdev, "%s: failed to resubmit tx bulk urb: %pe\n",
 959			   __func__, ERR_PTR(ret));
 960
 961		can_free_echo_skb(netdev, 0, NULL);
 962		stats->tx_dropped++;
 963		stats->tx_errors++;
 964
 965		if (ret == -ENODEV)
 966			netif_device_detach(netdev);
 967		else
 968			netif_wake_queue(netdev);
 969	}
 970
 971	/* let usb core take care of this urb */
 972	usb_free_urb(write_urb);
 973
 974	return NETDEV_TX_OK;
 975
 976nomem_buf:
 977	usb_free_urb(write_urb);
 978
 979nomem_urb:
 980	dev_kfree_skb(skb);
 981	stats->tx_dropped++;
 982	stats->tx_errors++;
 983	netif_wake_queue(netdev);
 984
 985	return NETDEV_TX_OK;
 986}
 987
 988static int f81604_get_berr_counter(const struct net_device *netdev,
 989				   struct can_berr_counter *bec)
 990{
 991	struct f81604_port_priv *priv = netdev_priv(netdev);
 992	u8 txerr, rxerr;
 993	int ret;
 994
 995	ret = f81604_sja1000_read(priv, F81604_SJA1000_TXERR, &txerr);
 996	if (ret)
 997		return ret;
 998
 999	ret = f81604_sja1000_read(priv, F81604_SJA1000_RXERR, &rxerr);
1000	if (ret)
1001		return ret;
1002
1003	bec->txerr = txerr;
1004	bec->rxerr = rxerr;
1005
1006	return 0;
1007}
1008
1009/* Open USB device */
1010static int f81604_open(struct net_device *netdev)
1011{
1012	int ret;
1013
1014	ret = open_candev(netdev);
1015	if (ret)
1016		return ret;
1017
1018	ret = f81604_start(netdev);
1019	if (ret) {
1020		if (ret == -ENODEV)
1021			netif_device_detach(netdev);
1022
1023		close_candev(netdev);
1024		return ret;
1025	}
1026
1027	netif_start_queue(netdev);
1028	return 0;
1029}
1030
1031/* Close USB device */
1032static int f81604_close(struct net_device *netdev)
1033{
1034	struct f81604_port_priv *priv = netdev_priv(netdev);
1035
1036	f81604_set_reset_mode(priv);
1037
1038	netif_stop_queue(netdev);
1039	cancel_work_sync(&priv->clear_reg_work);
1040	close_candev(netdev);
1041
1042	f81604_unregister_urbs(priv);
1043
1044	return 0;
1045}
1046
1047static const struct net_device_ops f81604_netdev_ops = {
1048	.ndo_open = f81604_open,
1049	.ndo_stop = f81604_close,
1050	.ndo_start_xmit = f81604_start_xmit,
1051	.ndo_change_mtu = can_change_mtu,
1052};
1053
1054static const struct can_bittiming_const f81604_bittiming_const = {
1055	.name = KBUILD_MODNAME,
1056	.tseg1_min = 1,
1057	.tseg1_max = 16,
1058	.tseg2_min = 1,
1059	.tseg2_max = 8,
1060	.sjw_max = 4,
1061	.brp_min = 1,
1062	.brp_max = 64,
1063	.brp_inc = 1,
1064};
1065
1066/* Called by the usb core when driver is unloaded or device is removed */
1067static void f81604_disconnect(struct usb_interface *intf)
1068{
1069	struct f81604_priv *priv = usb_get_intfdata(intf);
1070	int i;
1071
1072	for (i = 0; i < ARRAY_SIZE(priv->netdev); ++i) {
1073		if (!priv->netdev[i])
1074			continue;
1075
1076		unregister_netdev(priv->netdev[i]);
1077		free_candev(priv->netdev[i]);
1078	}
1079}
1080
1081static int __f81604_set_termination(struct usb_device *dev, int idx, u16 term)
1082{
1083	u8 mask, data = 0;
1084
1085	if (idx == 0)
1086		mask = F81604_CAN0_TERM;
1087	else
1088		mask = F81604_CAN1_TERM;
1089
1090	if (term)
1091		data = mask;
1092
1093	return f81604_update_bits(dev, F81604_TERMINATOR_REG, mask, data);
1094}
1095
1096static int f81604_set_termination(struct net_device *netdev, u16 term)
1097{
1098	struct f81604_port_priv *port_priv = netdev_priv(netdev);
1099
1100	ASSERT_RTNL();
1101
1102	return __f81604_set_termination(port_priv->dev, netdev->dev_port,
1103					term);
1104}
1105
1106static int f81604_probe(struct usb_interface *intf,
1107			const struct usb_device_id *id)
1108{
1109	struct usb_device *dev = interface_to_usbdev(intf);
1110	struct net_device *netdev;
1111	struct f81604_priv *priv;
1112	int i, ret;
1113
1114	priv = devm_kzalloc(&intf->dev, sizeof(*priv), GFP_KERNEL);
1115	if (!priv)
1116		return -ENOMEM;
1117
1118	usb_set_intfdata(intf, priv);
1119
1120	for (i = 0; i < ARRAY_SIZE(priv->netdev); ++i) {
1121		ret = __f81604_set_termination(dev, i, 0);
1122		if (ret) {
1123			dev_err(&intf->dev,
1124				"Setting termination of CH#%d failed: %pe\n",
1125				i, ERR_PTR(ret));
1126			return ret;
1127		}
1128	}
1129
1130	for (i = 0; i < ARRAY_SIZE(priv->netdev); ++i) {
1131		struct f81604_port_priv *port_priv;
1132
1133		netdev = alloc_candev(sizeof(*port_priv), 1);
1134		if (!netdev) {
1135			dev_err(&intf->dev, "Couldn't alloc candev: %d\n", i);
1136			ret = -ENOMEM;
1137
1138			goto failure_cleanup;
1139		}
1140
1141		port_priv = netdev_priv(netdev);
1142
1143		INIT_WORK(&port_priv->clear_reg_work, f81604_clear_reg_work);
1144		init_usb_anchor(&port_priv->urbs_anchor);
1145
1146		port_priv->intf = intf;
1147		port_priv->dev = dev;
1148		port_priv->netdev = netdev;
1149		port_priv->can.clock.freq = F81604_CAN_CLOCK;
1150
1151		port_priv->can.termination_const = f81604_termination;
1152		port_priv->can.termination_const_cnt =
1153			ARRAY_SIZE(f81604_termination);
1154		port_priv->can.bittiming_const = &f81604_bittiming_const;
1155		port_priv->can.do_set_bittiming = f81604_set_bittiming;
1156		port_priv->can.do_set_mode = f81604_set_mode;
1157		port_priv->can.do_set_termination = f81604_set_termination;
1158		port_priv->can.do_get_berr_counter = f81604_get_berr_counter;
1159		port_priv->can.ctrlmode_supported =
1160			CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
1161			CAN_CTRLMODE_ONE_SHOT | CAN_CTRLMODE_BERR_REPORTING |
1162			CAN_CTRLMODE_PRESUME_ACK;
1163
1164		netdev->ethtool_ops = &f81604_ethtool_ops;
1165		netdev->netdev_ops = &f81604_netdev_ops;
1166		netdev->flags |= IFF_ECHO;
1167		netdev->dev_port = i;
1168
1169		SET_NETDEV_DEV(netdev, &intf->dev);
1170
1171		ret = register_candev(netdev);
1172		if (ret) {
1173			netdev_err(netdev, "register CAN device failed: %pe\n",
1174				   ERR_PTR(ret));
1175			free_candev(netdev);
1176
1177			goto failure_cleanup;
1178		}
1179
1180		priv->netdev[i] = netdev;
1181	}
1182
1183	return 0;
1184
1185failure_cleanup:
1186	f81604_disconnect(intf);
1187	return ret;
1188}
1189
1190static struct usb_driver f81604_driver = {
1191	.name = KBUILD_MODNAME,
1192	.probe = f81604_probe,
1193	.disconnect = f81604_disconnect,
1194	.id_table = f81604_table,
1195};
1196
1197module_usb_driver(f81604_driver);
1198
1199MODULE_AUTHOR("Ji-Ze Hong (Peter Hong) <peter_hong@fintek.com.tw>");
1200MODULE_DESCRIPTION("Fintek F81604 USB to 2xCANBUS");
1201MODULE_LICENSE("GPL");