1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Janz MODULbus VMOD-ICAN3 CAN Interface Driver
   4 *
   5 * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/module.h>
  10#include <linux/interrupt.h>
  11#include <linux/delay.h>
  12#include <linux/ethtool.h>
  13#include <linux/platform_device.h>
  14
  15#include <linux/netdevice.h>
  16#include <linux/can.h>
  17#include <linux/can/dev.h>
  18#include <linux/can/skb.h>
  19#include <linux/can/error.h>
  20
  21#include <linux/mfd/janz.h>
  22#include <asm/io.h>
  23
  24/* the DPM has 64k of memory, organized into 256x 256 byte pages */
  25#define DPM_NUM_PAGES		256
  26#define DPM_PAGE_SIZE		256
  27#define DPM_PAGE_ADDR(p)	((p) * DPM_PAGE_SIZE)
  28
  29/* JANZ ICAN3 "old-style" host interface queue page numbers */
  30#define QUEUE_OLD_CONTROL	0
  31#define QUEUE_OLD_RB0		1
  32#define QUEUE_OLD_RB1		2
  33#define QUEUE_OLD_WB0		3
  34#define QUEUE_OLD_WB1		4
  35
  36/* Janz ICAN3 "old-style" host interface control registers */
  37#define MSYNC_PEER		0x00		/* ICAN only */
  38#define MSYNC_LOCL		0x01		/* host only */
  39#define TARGET_RUNNING		0x02
  40#define FIRMWARE_STAMP		0x60		/* big endian firmware stamp */
  41
  42#define MSYNC_RB0		0x01
  43#define MSYNC_RB1		0x02
  44#define MSYNC_RBLW		0x04
  45#define MSYNC_RB_MASK		(MSYNC_RB0 | MSYNC_RB1)
  46
  47#define MSYNC_WB0		0x10
  48#define MSYNC_WB1		0x20
  49#define MSYNC_WBLW		0x40
  50#define MSYNC_WB_MASK		(MSYNC_WB0 | MSYNC_WB1)
  51
  52/* Janz ICAN3 "new-style" host interface queue page numbers */
  53#define QUEUE_TOHOST		5
  54#define QUEUE_FROMHOST_MID	6
  55#define QUEUE_FROMHOST_HIGH	7
  56#define QUEUE_FROMHOST_LOW	8
  57
  58/* The first free page in the DPM is #9 */
  59#define DPM_FREE_START		9
  60
  61/* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */
  62#define DESC_VALID		0x80
  63#define DESC_WRAP		0x40
  64#define DESC_INTERRUPT		0x20
  65#define DESC_IVALID		0x10
  66#define DESC_LEN(len)		(len)
  67
  68/* Janz ICAN3 Firmware Messages */
  69#define MSG_CONNECTI		0x02
  70#define MSG_DISCONNECT		0x03
  71#define MSG_IDVERS		0x04
  72#define MSG_MSGLOST		0x05
  73#define MSG_NEWHOSTIF		0x08
  74#define MSG_INQUIRY		0x0a
  75#define MSG_SETAFILMASK		0x10
  76#define MSG_INITFDPMQUEUE	0x11
  77#define MSG_HWCONF		0x12
  78#define MSG_FMSGLOST		0x15
  79#define MSG_CEVTIND		0x37
  80#define MSG_CBTRREQ		0x41
  81#define MSG_COFFREQ		0x42
  82#define MSG_CONREQ		0x43
  83#define MSG_CCONFREQ		0x47
  84#define MSG_NMTS		0xb0
  85#define MSG_LMTS		0xb4
  86
  87/*
  88 * Janz ICAN3 CAN Inquiry Message Types
  89 *
  90 * NOTE: there appears to be a firmware bug here. You must send
  91 * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED
  92 * NOTE: response. The controller never responds to a message with
  93 * NOTE: the INQUIRY_EXTENDED subspec :(
  94 */
  95#define INQUIRY_STATUS		0x00
  96#define INQUIRY_TERMINATION	0x01
  97#define INQUIRY_EXTENDED	0x04
  98
  99/* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */
 100#define SETAFILMASK_REJECT	0x00
 101#define SETAFILMASK_FASTIF	0x02
 102
 103/* Janz ICAN3 CAN Hardware Configuration Message Types */
 104#define HWCONF_TERMINATE_ON	0x01
 105#define HWCONF_TERMINATE_OFF	0x00
 106
 107/* Janz ICAN3 CAN Event Indication Message Types */
 108#define CEVTIND_EI		0x01
 109#define CEVTIND_DOI		0x02
 110#define CEVTIND_LOST		0x04
 111#define CEVTIND_FULL		0x08
 112#define CEVTIND_BEI		0x10
 113
 114#define CEVTIND_CHIP_SJA1000	0x02
 115
 116#define ICAN3_BUSERR_QUOTA_MAX	255
 117
 118/* Janz ICAN3 CAN Frame Conversion */
 119#define ICAN3_SNGL	0x02
 120#define ICAN3_ECHO	0x10
 121#define ICAN3_EFF_RTR	0x40
 122#define ICAN3_SFF_RTR	0x10
 123#define ICAN3_EFF	0x80
 124
 125#define ICAN3_CAN_TYPE_MASK	0x0f
 126#define ICAN3_CAN_TYPE_SFF	0x00
 127#define ICAN3_CAN_TYPE_EFF	0x01
 128
 129#define ICAN3_CAN_DLC_MASK	0x0f
 130
 131/* Janz ICAN3 NMTS subtypes */
 132#define NMTS_CREATE_NODE_REQ	0x0
 133#define NMTS_SLAVE_STATE_IND	0x8
 134#define NMTS_SLAVE_EVENT_IND	0x9
 135
 136/* Janz ICAN3 LMTS subtypes */
 137#define LMTS_BUSON_REQ		0x0
 138#define LMTS_BUSOFF_REQ		0x1
 139#define LMTS_CAN_CONF_REQ	0x2
 140
 141/* Janz ICAN3 NMTS Event indications */
 142#define NE_LOCAL_OCCURRED	0x3
 143#define NE_LOCAL_RESOLVED	0x2
 144#define NE_REMOTE_OCCURRED	0xc
 145#define NE_REMOTE_RESOLVED	0x8
 146
 147/*
 148 * SJA1000 Status and Error Register Definitions
 149 *
 150 * Copied from drivers/net/can/sja1000/sja1000.h
 151 */
 152
 153/* status register content */
 154#define SR_BS		0x80
 155#define SR_ES		0x40
 156#define SR_TS		0x20
 157#define SR_RS		0x10
 158#define SR_TCS		0x08
 159#define SR_TBS		0x04
 160#define SR_DOS		0x02
 161#define SR_RBS		0x01
 162
 163#define SR_CRIT (SR_BS|SR_ES)
 164
 165/* ECC register */
 166#define ECC_SEG		0x1F
 167#define ECC_DIR		0x20
 168#define ECC_ERR		6
 169#define ECC_BIT		0x00
 170#define ECC_FORM	0x40
 171#define ECC_STUFF	0x80
 172#define ECC_MASK	0xc0
 173
 174/* Number of buffers for use in the "new-style" host interface */
 175#define ICAN3_NEW_BUFFERS	16
 176
 177/* Number of buffers for use in the "fast" host interface */
 178#define ICAN3_TX_BUFFERS	512
 179#define ICAN3_RX_BUFFERS	1024
 180
 181/* SJA1000 Clock Input */
 182#define ICAN3_CAN_CLOCK		8000000
 183
 184/* Janz ICAN3 firmware types */
 185enum ican3_fwtype {
 186	ICAN3_FWTYPE_ICANOS,
 187	ICAN3_FWTYPE_CAL_CANOPEN,
 188};
 189
 190/* Driver Name */
 191#define DRV_NAME "janz-ican3"
 192
 193/* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */
 194struct ican3_dpm_control {
 195	/* window address register */
 196	u8 window_address;
 197	u8 unused1;
 198
 199	/*
 200	 * Read access: clear interrupt from microcontroller
 201	 * Write access: send interrupt to microcontroller
 202	 */
 203	u8 interrupt;
 204	u8 unused2;
 205
 206	/* write-only: reset all hardware on the module */
 207	u8 hwreset;
 208	u8 unused3;
 209
 210	/* write-only: generate an interrupt to the TPU */
 211	u8 tpuinterrupt;
 212};
 213
 214struct ican3_dev {
 215
 216	/* must be the first member */
 217	struct can_priv can;
 218
 219	/* CAN network device */
 220	struct net_device *ndev;
 221	struct napi_struct napi;
 222
 223	/* module number */
 224	unsigned int num;
 225
 226	/* base address of registers and IRQ */
 227	struct janz_cmodio_onboard_regs __iomem *ctrl;
 228	struct ican3_dpm_control __iomem *dpmctrl;
 229	void __iomem *dpm;
 230	int irq;
 231
 232	/* CAN bus termination status */
 233	struct completion termination_comp;
 234	bool termination_enabled;
 235
 236	/* CAN bus error status registers */
 237	struct completion buserror_comp;
 238	struct can_berr_counter bec;
 239
 240	/* firmware type */
 241	enum ican3_fwtype fwtype;
 242	char fwinfo[32];
 243
 244	/* old and new style host interface */
 245	unsigned int iftype;
 246
 247	/* queue for echo packets */
 248	struct sk_buff_head echoq;
 249
 250	/*
 251	 * Any function which changes the current DPM page must hold this
 252	 * lock while it is performing data accesses. This ensures that the
 253	 * function will not be preempted and end up reading data from a
 254	 * different DPM page than it expects.
 255	 */
 256	spinlock_t lock;
 257
 258	/* new host interface */
 259	unsigned int rx_int;
 260	unsigned int rx_num;
 261	unsigned int tx_num;
 262
 263	/* fast host interface */
 264	unsigned int fastrx_start;
 265	unsigned int fastrx_num;
 266	unsigned int fasttx_start;
 267	unsigned int fasttx_num;
 268
 269	/* first free DPM page */
 270	unsigned int free_page;
 271};
 272
 273struct ican3_msg {
 274	u8 control;
 275	u8 spec;
 276	__le16 len;
 277	u8 data[252];
 278};
 279
 280struct ican3_new_desc {
 281	u8 control;
 282	u8 pointer;
 283};
 284
 285struct ican3_fast_desc {
 286	u8 control;
 287	u8 command;
 288	u8 data[14];
 289};
 290
 291/* write to the window basic address register */
 292static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page)
 293{
 294	BUG_ON(page >= DPM_NUM_PAGES);
 295	iowrite8(page, &mod->dpmctrl->window_address);
 296}
 297
 298/*
 299 * ICAN3 "old-style" host interface
 300 */
 301
 302/*
 303 * Receive a message from the ICAN3 "old-style" firmware interface
 304 *
 305 * LOCKING: must hold mod->lock
 306 *
 307 * returns 0 on success, -ENOMEM when no message exists
 308 */
 309static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 310{
 311	unsigned int mbox, mbox_page;
 312	u8 locl, peer, xord;
 313
 314	/* get the MSYNC registers */
 315	ican3_set_page(mod, QUEUE_OLD_CONTROL);
 316	peer = ioread8(mod->dpm + MSYNC_PEER);
 317	locl = ioread8(mod->dpm + MSYNC_LOCL);
 318	xord = locl ^ peer;
 319
 320	if ((xord & MSYNC_RB_MASK) == 0x00) {
 321		netdev_dbg(mod->ndev, "no mbox for reading\n");
 322		return -ENOMEM;
 323	}
 324
 325	/* find the first free mbox to read */
 326	if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK)
 327		mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1;
 328	else
 329		mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1;
 330
 331	/* copy the message */
 332	mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1;
 333	ican3_set_page(mod, mbox_page);
 334	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
 335
 336	/*
 337	 * notify the firmware that the read buffer is available
 338	 * for it to fill again
 339	 */
 340	locl ^= mbox;
 341
 342	ican3_set_page(mod, QUEUE_OLD_CONTROL);
 343	iowrite8(locl, mod->dpm + MSYNC_LOCL);
 344	return 0;
 345}
 346
 347/*
 348 * Send a message through the "old-style" firmware interface
 349 *
 350 * LOCKING: must hold mod->lock
 351 *
 352 * returns 0 on success, -ENOMEM when no free space exists
 353 */
 354static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 355{
 356	unsigned int mbox, mbox_page;
 357	u8 locl, peer, xord;
 358
 359	/* get the MSYNC registers */
 360	ican3_set_page(mod, QUEUE_OLD_CONTROL);
 361	peer = ioread8(mod->dpm + MSYNC_PEER);
 362	locl = ioread8(mod->dpm + MSYNC_LOCL);
 363	xord = locl ^ peer;
 364
 365	if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) {
 366		netdev_err(mod->ndev, "no mbox for writing\n");
 367		return -ENOMEM;
 368	}
 369
 370	/* calculate a free mbox to use */
 371	mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0;
 372
 373	/* copy the message to the DPM */
 374	mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1;
 375	ican3_set_page(mod, mbox_page);
 376	memcpy_toio(mod->dpm, msg, sizeof(*msg));
 377
 378	locl ^= mbox;
 379	if (mbox == MSYNC_WB1)
 380		locl |= MSYNC_WBLW;
 381
 382	ican3_set_page(mod, QUEUE_OLD_CONTROL);
 383	iowrite8(locl, mod->dpm + MSYNC_LOCL);
 384	return 0;
 385}
 386
 387/*
 388 * ICAN3 "new-style" Host Interface Setup
 389 */
 390
 391static void ican3_init_new_host_interface(struct ican3_dev *mod)
 392{
 393	struct ican3_new_desc desc;
 394	unsigned long flags;
 395	void __iomem *dst;
 396	int i;
 397
 398	spin_lock_irqsave(&mod->lock, flags);
 399
 400	/* setup the internal datastructures for RX */
 401	mod->rx_num = 0;
 402	mod->rx_int = 0;
 403
 404	/* tohost queue descriptors are in page 5 */
 405	ican3_set_page(mod, QUEUE_TOHOST);
 406	dst = mod->dpm;
 407
 408	/* initialize the tohost (rx) queue descriptors: pages 9-24 */
 409	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
 410		desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */
 411		desc.pointer = mod->free_page;
 412
 413		/* set wrap flag on last buffer */
 414		if (i == ICAN3_NEW_BUFFERS - 1)
 415			desc.control |= DESC_WRAP;
 416
 417		memcpy_toio(dst, &desc, sizeof(desc));
 418		dst += sizeof(desc);
 419		mod->free_page++;
 420	}
 421
 422	/* fromhost (tx) mid queue descriptors are in page 6 */
 423	ican3_set_page(mod, QUEUE_FROMHOST_MID);
 424	dst = mod->dpm;
 425
 426	/* setup the internal datastructures for TX */
 427	mod->tx_num = 0;
 428
 429	/* initialize the fromhost mid queue descriptors: pages 25-40 */
 430	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
 431		desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */
 432		desc.pointer = mod->free_page;
 433
 434		/* set wrap flag on last buffer */
 435		if (i == ICAN3_NEW_BUFFERS - 1)
 436			desc.control |= DESC_WRAP;
 437
 438		memcpy_toio(dst, &desc, sizeof(desc));
 439		dst += sizeof(desc);
 440		mod->free_page++;
 441	}
 442
 443	/* fromhost hi queue descriptors are in page 7 */
 444	ican3_set_page(mod, QUEUE_FROMHOST_HIGH);
 445	dst = mod->dpm;
 446
 447	/* initialize only a single buffer in the fromhost hi queue (unused) */
 448	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
 449	desc.pointer = mod->free_page;
 450	memcpy_toio(dst, &desc, sizeof(desc));
 451	mod->free_page++;
 452
 453	/* fromhost low queue descriptors are in page 8 */
 454	ican3_set_page(mod, QUEUE_FROMHOST_LOW);
 455	dst = mod->dpm;
 456
 457	/* initialize only a single buffer in the fromhost low queue (unused) */
 458	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
 459	desc.pointer = mod->free_page;
 460	memcpy_toio(dst, &desc, sizeof(desc));
 461	mod->free_page++;
 462
 463	spin_unlock_irqrestore(&mod->lock, flags);
 464}
 465
 466/*
 467 * ICAN3 Fast Host Interface Setup
 468 */
 469
 470static void ican3_init_fast_host_interface(struct ican3_dev *mod)
 471{
 472	struct ican3_fast_desc desc;
 473	unsigned long flags;
 474	unsigned int addr;
 475	void __iomem *dst;
 476	int i;
 477
 478	spin_lock_irqsave(&mod->lock, flags);
 479
 480	/* save the start recv page */
 481	mod->fastrx_start = mod->free_page;
 482	mod->fastrx_num = 0;
 483
 484	/* build a single fast tohost queue descriptor */
 485	memset(&desc, 0, sizeof(desc));
 486	desc.control = 0x00;
 487	desc.command = 1;
 488
 489	/* build the tohost queue descriptor ring in memory */
 490	addr = 0;
 491	for (i = 0; i < ICAN3_RX_BUFFERS; i++) {
 492
 493		/* set the wrap bit on the last buffer */
 494		if (i == ICAN3_RX_BUFFERS - 1)
 495			desc.control |= DESC_WRAP;
 496
 497		/* switch to the correct page */
 498		ican3_set_page(mod, mod->free_page);
 499
 500		/* copy the descriptor to the DPM */
 501		dst = mod->dpm + addr;
 502		memcpy_toio(dst, &desc, sizeof(desc));
 503		addr += sizeof(desc);
 504
 505		/* move to the next page if necessary */
 506		if (addr >= DPM_PAGE_SIZE) {
 507			addr = 0;
 508			mod->free_page++;
 509		}
 510	}
 511
 512	/* make sure we page-align the next queue */
 513	if (addr != 0)
 514		mod->free_page++;
 515
 516	/* save the start xmit page */
 517	mod->fasttx_start = mod->free_page;
 518	mod->fasttx_num = 0;
 519
 520	/* build a single fast fromhost queue descriptor */
 521	memset(&desc, 0, sizeof(desc));
 522	desc.control = DESC_VALID;
 523	desc.command = 1;
 524
 525	/* build the fromhost queue descriptor ring in memory */
 526	addr = 0;
 527	for (i = 0; i < ICAN3_TX_BUFFERS; i++) {
 528
 529		/* set the wrap bit on the last buffer */
 530		if (i == ICAN3_TX_BUFFERS - 1)
 531			desc.control |= DESC_WRAP;
 532
 533		/* switch to the correct page */
 534		ican3_set_page(mod, mod->free_page);
 535
 536		/* copy the descriptor to the DPM */
 537		dst = mod->dpm + addr;
 538		memcpy_toio(dst, &desc, sizeof(desc));
 539		addr += sizeof(desc);
 540
 541		/* move to the next page if necessary */
 542		if (addr >= DPM_PAGE_SIZE) {
 543			addr = 0;
 544			mod->free_page++;
 545		}
 546	}
 547
 548	spin_unlock_irqrestore(&mod->lock, flags);
 549}
 550
 551/*
 552 * ICAN3 "new-style" Host Interface Message Helpers
 553 */
 554
 555/*
 556 * LOCKING: must hold mod->lock
 557 */
 558static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 559{
 560	struct ican3_new_desc desc;
 561	void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc));
 562
 563	/* switch to the fromhost mid queue, and read the buffer descriptor */
 564	ican3_set_page(mod, QUEUE_FROMHOST_MID);
 565	memcpy_fromio(&desc, desc_addr, sizeof(desc));
 566
 567	if (!(desc.control & DESC_VALID)) {
 568		netdev_dbg(mod->ndev, "%s: no free buffers\n", __func__);
 569		return -ENOMEM;
 570	}
 571
 572	/* switch to the data page, copy the data */
 573	ican3_set_page(mod, desc.pointer);
 574	memcpy_toio(mod->dpm, msg, sizeof(*msg));
 575
 576	/* switch back to the descriptor, set the valid bit, write it back */
 577	ican3_set_page(mod, QUEUE_FROMHOST_MID);
 578	desc.control ^= DESC_VALID;
 579	memcpy_toio(desc_addr, &desc, sizeof(desc));
 580
 581	/* update the tx number */
 582	mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1);
 583	return 0;
 584}
 585
 586/*
 587 * LOCKING: must hold mod->lock
 588 */
 589static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 590{
 591	struct ican3_new_desc desc;
 592	void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc));
 593
 594	/* switch to the tohost queue, and read the buffer descriptor */
 595	ican3_set_page(mod, QUEUE_TOHOST);
 596	memcpy_fromio(&desc, desc_addr, sizeof(desc));
 597
 598	if (!(desc.control & DESC_VALID)) {
 599		netdev_dbg(mod->ndev, "%s: no buffers to recv\n", __func__);
 600		return -ENOMEM;
 601	}
 602
 603	/* switch to the data page, copy the data */
 604	ican3_set_page(mod, desc.pointer);
 605	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
 606
 607	/* switch back to the descriptor, toggle the valid bit, write it back */
 608	ican3_set_page(mod, QUEUE_TOHOST);
 609	desc.control ^= DESC_VALID;
 610	memcpy_toio(desc_addr, &desc, sizeof(desc));
 611
 612	/* update the rx number */
 613	mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1);
 614	return 0;
 615}
 616
 617/*
 618 * Message Send / Recv Helpers
 619 */
 620
 621static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 622{
 623	unsigned long flags;
 624	int ret;
 625
 626	spin_lock_irqsave(&mod->lock, flags);
 627
 628	if (mod->iftype == 0)
 629		ret = ican3_old_send_msg(mod, msg);
 630	else
 631		ret = ican3_new_send_msg(mod, msg);
 632
 633	spin_unlock_irqrestore(&mod->lock, flags);
 634	return ret;
 635}
 636
 637static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
 638{
 639	unsigned long flags;
 640	int ret;
 641
 642	spin_lock_irqsave(&mod->lock, flags);
 643
 644	if (mod->iftype == 0)
 645		ret = ican3_old_recv_msg(mod, msg);
 646	else
 647		ret = ican3_new_recv_msg(mod, msg);
 648
 649	spin_unlock_irqrestore(&mod->lock, flags);
 650	return ret;
 651}
 652
 653/*
 654 * Quick Pre-constructed Messages
 655 */
 656
 657static int ican3_msg_connect(struct ican3_dev *mod)
 658{
 659	struct ican3_msg msg;
 660
 661	memset(&msg, 0, sizeof(msg));
 662	msg.spec = MSG_CONNECTI;
 663	msg.len = cpu_to_le16(0);
 664
 665	return ican3_send_msg(mod, &msg);
 666}
 667
 668static int ican3_msg_disconnect(struct ican3_dev *mod)
 669{
 670	struct ican3_msg msg;
 671
 672	memset(&msg, 0, sizeof(msg));
 673	msg.spec = MSG_DISCONNECT;
 674	msg.len = cpu_to_le16(0);
 675
 676	return ican3_send_msg(mod, &msg);
 677}
 678
 679static int ican3_msg_newhostif(struct ican3_dev *mod)
 680{
 681	struct ican3_msg msg;
 682	int ret;
 683
 684	memset(&msg, 0, sizeof(msg));
 685	msg.spec = MSG_NEWHOSTIF;
 686	msg.len = cpu_to_le16(0);
 687
 688	/* If we're not using the old interface, switching seems bogus */
 689	WARN_ON(mod->iftype != 0);
 690
 691	ret = ican3_send_msg(mod, &msg);
 692	if (ret)
 693		return ret;
 694
 695	/* mark the module as using the new host interface */
 696	mod->iftype = 1;
 697	return 0;
 698}
 699
 700static int ican3_msg_fasthostif(struct ican3_dev *mod)
 701{
 702	struct ican3_msg msg;
 703	unsigned int addr;
 704
 705	memset(&msg, 0, sizeof(msg));
 706	msg.spec = MSG_INITFDPMQUEUE;
 707	msg.len = cpu_to_le16(8);
 708
 709	/* write the tohost queue start address */
 710	addr = DPM_PAGE_ADDR(mod->fastrx_start);
 711	msg.data[0] = addr & 0xff;
 712	msg.data[1] = (addr >> 8) & 0xff;
 713	msg.data[2] = (addr >> 16) & 0xff;
 714	msg.data[3] = (addr >> 24) & 0xff;
 715
 716	/* write the fromhost queue start address */
 717	addr = DPM_PAGE_ADDR(mod->fasttx_start);
 718	msg.data[4] = addr & 0xff;
 719	msg.data[5] = (addr >> 8) & 0xff;
 720	msg.data[6] = (addr >> 16) & 0xff;
 721	msg.data[7] = (addr >> 24) & 0xff;
 722
 723	/* If we're not using the new interface yet, we cannot do this */
 724	WARN_ON(mod->iftype != 1);
 725
 726	return ican3_send_msg(mod, &msg);
 727}
 728
 729/*
 730 * Setup the CAN filter to either accept or reject all
 731 * messages from the CAN bus.
 732 */
 733static int ican3_set_id_filter(struct ican3_dev *mod, bool accept)
 734{
 735	struct ican3_msg msg;
 736	int ret;
 737
 738	/* Standard Frame Format */
 739	memset(&msg, 0, sizeof(msg));
 740	msg.spec = MSG_SETAFILMASK;
 741	msg.len = cpu_to_le16(5);
 742	msg.data[0] = 0x00; /* IDLo LSB */
 743	msg.data[1] = 0x00; /* IDLo MSB */
 744	msg.data[2] = 0xff; /* IDHi LSB */
 745	msg.data[3] = 0x07; /* IDHi MSB */
 746
 747	/* accept all frames for fast host if, or reject all frames */
 748	msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
 749
 750	ret = ican3_send_msg(mod, &msg);
 751	if (ret)
 752		return ret;
 753
 754	/* Extended Frame Format */
 755	memset(&msg, 0, sizeof(msg));
 756	msg.spec = MSG_SETAFILMASK;
 757	msg.len = cpu_to_le16(13);
 758	msg.data[0] = 0;    /* MUX = 0 */
 759	msg.data[1] = 0x00; /* IDLo LSB */
 760	msg.data[2] = 0x00;
 761	msg.data[3] = 0x00;
 762	msg.data[4] = 0x20; /* IDLo MSB */
 763	msg.data[5] = 0xff; /* IDHi LSB */
 764	msg.data[6] = 0xff;
 765	msg.data[7] = 0xff;
 766	msg.data[8] = 0x3f; /* IDHi MSB */
 767
 768	/* accept all frames for fast host if, or reject all frames */
 769	msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
 770
 771	return ican3_send_msg(mod, &msg);
 772}
 773
 774/*
 775 * Bring the CAN bus online or offline
 776 */
 777static int ican3_set_bus_state(struct ican3_dev *mod, bool on)
 778{
 779	struct can_bittiming *bt = &mod->can.bittiming;
 780	struct ican3_msg msg;
 781	u8 btr0, btr1;
 782	int res;
 783
 784	/* This algorithm was stolen from drivers/net/can/sja1000/sja1000.c      */
 785	/* The bittiming register command for the ICAN3 just sets the bit timing */
 786	/* registers on the SJA1000 chip directly                                */
 787	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 788	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 789		(((bt->phase_seg2 - 1) & 0x7) << 4);
 790	if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 791		btr1 |= 0x80;
 792
 793	if (mod->fwtype == ICAN3_FWTYPE_ICANOS) {
 794		if (on) {
 795			/* set bittiming */
 796			memset(&msg, 0, sizeof(msg));
 797			msg.spec = MSG_CBTRREQ;
 798			msg.len = cpu_to_le16(4);
 799			msg.data[0] = 0x00;
 800			msg.data[1] = 0x00;
 801			msg.data[2] = btr0;
 802			msg.data[3] = btr1;
 803
 804			res = ican3_send_msg(mod, &msg);
 805			if (res)
 806				return res;
 807		}
 808
 809		/* can-on/off request */
 810		memset(&msg, 0, sizeof(msg));
 811		msg.spec = on ? MSG_CONREQ : MSG_COFFREQ;
 812		msg.len = cpu_to_le16(0);
 813
 814		return ican3_send_msg(mod, &msg);
 815
 816	} else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) {
 817		/* bittiming + can-on/off request */
 818		memset(&msg, 0, sizeof(msg));
 819		msg.spec = MSG_LMTS;
 820		if (on) {
 821			msg.len = cpu_to_le16(4);
 822			msg.data[0] = LMTS_BUSON_REQ;
 823			msg.data[1] = 0;
 824			msg.data[2] = btr0;
 825			msg.data[3] = btr1;
 826		} else {
 827			msg.len = cpu_to_le16(2);
 828			msg.data[0] = LMTS_BUSOFF_REQ;
 829			msg.data[1] = 0;
 830		}
 831		res = ican3_send_msg(mod, &msg);
 832		if (res)
 833			return res;
 834
 835		if (on) {
 836			/* create NMT Slave Node for error processing
 837			 *   class 2 (with error capability, see CiA/DS203-1)
 838			 *   id    1
 839			 *   name  locnod1 (must be exactly 7 bytes)
 840			 */
 841			memset(&msg, 0, sizeof(msg));
 842			msg.spec = MSG_NMTS;
 843			msg.len = cpu_to_le16(11);
 844			msg.data[0] = NMTS_CREATE_NODE_REQ;
 845			msg.data[1] = 0;
 846			msg.data[2] = 2;                 /* node class */
 847			msg.data[3] = 1;                 /* node id */
 848			strcpy(msg.data + 4, "locnod1"); /* node name  */
 849			return ican3_send_msg(mod, &msg);
 850		}
 851		return 0;
 852	}
 853	return -ENOTSUPP;
 854}
 855
 856static int ican3_set_termination(struct ican3_dev *mod, bool on)
 857{
 858	struct ican3_msg msg;
 859
 860	memset(&msg, 0, sizeof(msg));
 861	msg.spec = MSG_HWCONF;
 862	msg.len = cpu_to_le16(2);
 863	msg.data[0] = 0x00;
 864	msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF;
 865
 866	return ican3_send_msg(mod, &msg);
 867}
 868
 869static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec)
 870{
 871	struct ican3_msg msg;
 872
 873	memset(&msg, 0, sizeof(msg));
 874	msg.spec = MSG_INQUIRY;
 875	msg.len = cpu_to_le16(2);
 876	msg.data[0] = subspec;
 877	msg.data[1] = 0x00;
 878
 879	return ican3_send_msg(mod, &msg);
 880}
 881
 882static int ican3_set_buserror(struct ican3_dev *mod, u8 quota)
 883{
 884	struct ican3_msg msg;
 885
 886	if (mod->fwtype == ICAN3_FWTYPE_ICANOS) {
 887		memset(&msg, 0, sizeof(msg));
 888		msg.spec = MSG_CCONFREQ;
 889		msg.len = cpu_to_le16(2);
 890		msg.data[0] = 0x00;
 891		msg.data[1] = quota;
 892	} else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) {
 893		memset(&msg, 0, sizeof(msg));
 894		msg.spec = MSG_LMTS;
 895		msg.len = cpu_to_le16(4);
 896		msg.data[0] = LMTS_CAN_CONF_REQ;
 897		msg.data[1] = 0x00;
 898		msg.data[2] = 0x00;
 899		msg.data[3] = quota;
 900	} else {
 901		return -ENOTSUPP;
 902	}
 903	return ican3_send_msg(mod, &msg);
 904}
 905
 906/*
 907 * ICAN3 to Linux CAN Frame Conversion
 908 */
 909
 910static void ican3_to_can_frame(struct ican3_dev *mod,
 911			       struct ican3_fast_desc *desc,
 912			       struct can_frame *cf)
 913{
 914	if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) {
 915		if (desc->data[1] & ICAN3_SFF_RTR)
 916			cf->can_id |= CAN_RTR_FLAG;
 917
 918		cf->can_id |= desc->data[0] << 3;
 919		cf->can_id |= (desc->data[1] & 0xe0) >> 5;
 920		cf->len = can_cc_dlc2len(desc->data[1] & ICAN3_CAN_DLC_MASK);
 921		memcpy(cf->data, &desc->data[2], cf->len);
 922	} else {
 923		cf->len = can_cc_dlc2len(desc->data[0] & ICAN3_CAN_DLC_MASK);
 924		if (desc->data[0] & ICAN3_EFF_RTR)
 925			cf->can_id |= CAN_RTR_FLAG;
 926
 927		if (desc->data[0] & ICAN3_EFF) {
 928			cf->can_id |= CAN_EFF_FLAG;
 929			cf->can_id |= desc->data[2] << 21; /* 28-21 */
 930			cf->can_id |= desc->data[3] << 13; /* 20-13 */
 931			cf->can_id |= desc->data[4] << 5;  /* 12-5  */
 932			cf->can_id |= (desc->data[5] & 0xf8) >> 3;
 933		} else {
 934			cf->can_id |= desc->data[2] << 3;  /* 10-3  */
 935			cf->can_id |= desc->data[3] >> 5;  /* 2-0   */
 936		}
 937
 938		memcpy(cf->data, &desc->data[6], cf->len);
 939	}
 940}
 941
 942static void can_frame_to_ican3(struct ican3_dev *mod,
 943			       struct can_frame *cf,
 944			       struct ican3_fast_desc *desc)
 945{
 946	/* clear out any stale data in the descriptor */
 947	memset(desc->data, 0, sizeof(desc->data));
 948
 949	/* we always use the extended format, with the ECHO flag set */
 950	desc->command = ICAN3_CAN_TYPE_EFF;
 951	desc->data[0] |= cf->len;
 952	desc->data[1] |= ICAN3_ECHO;
 953
 954	/* support single transmission (no retries) mode */
 955	if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 956		desc->data[1] |= ICAN3_SNGL;
 957
 958	if (cf->can_id & CAN_RTR_FLAG)
 959		desc->data[0] |= ICAN3_EFF_RTR;
 960
 961	/* pack the id into the correct places */
 962	if (cf->can_id & CAN_EFF_FLAG) {
 963		desc->data[0] |= ICAN3_EFF;
 964		desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */
 965		desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */
 966		desc->data[4] = (cf->can_id & 0x00001fe0) >> 5;  /* 12-5  */
 967		desc->data[5] = (cf->can_id & 0x0000001f) << 3;  /* 4-0   */
 968	} else {
 969		desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */
 970		desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0  */
 971	}
 972
 973	/* copy the data bits into the descriptor */
 974	memcpy(&desc->data[6], cf->data, cf->len);
 975}
 976
 977/*
 978 * Interrupt Handling
 979 */
 980
 981/*
 982 * Handle an ID + Version message response from the firmware. We never generate
 983 * this message in production code, but it is very useful when debugging to be
 984 * able to display this message.
 985 */
 986static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg)
 987{
 988	netdev_dbg(mod->ndev, "IDVERS response: %s\n", msg->data);
 989}
 990
 991static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg)
 992{
 993	struct net_device *dev = mod->ndev;
 994	struct net_device_stats *stats = &dev->stats;
 995	struct can_frame *cf;
 996	struct sk_buff *skb;
 997
 998	/*
 999	 * Report that communication messages with the microcontroller firmware
1000	 * are being lost. These are never CAN frames, so we do not generate an
1001	 * error frame for userspace
1002	 */
1003	if (msg->spec == MSG_MSGLOST) {
1004		netdev_err(mod->ndev, "lost %d control messages\n", msg->data[0]);
1005		return;
1006	}
1007
1008	/*
1009	 * Oops, this indicates that we have lost messages in the fast queue,
1010	 * which are exclusively CAN messages. Our driver isn't reading CAN
1011	 * frames fast enough.
1012	 *
1013	 * We'll pretend that the SJA1000 told us that it ran out of buffer
1014	 * space, because there is not a better message for this.
1015	 */
1016	skb = alloc_can_err_skb(dev, &cf);
1017	if (skb) {
1018		cf->can_id |= CAN_ERR_CRTL;
1019		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
1020		stats->rx_over_errors++;
1021		stats->rx_errors++;
1022		netif_rx(skb);
1023	}
1024}
1025
1026/*
1027 * Handle CAN Event Indication Messages from the firmware
1028 *
1029 * The ICAN3 firmware provides the values of some SJA1000 registers when it
1030 * generates this message. The code below is largely copied from the
1031 * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary
1032 */
1033static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg)
1034{
1035	struct net_device *dev = mod->ndev;
1036	struct net_device_stats *stats = &dev->stats;
1037	enum can_state state = mod->can.state;
1038	u8 isrc, ecc, status, rxerr, txerr;
1039	struct can_frame *cf;
1040	struct sk_buff *skb;
1041
1042	/* we can only handle the SJA1000 part */
1043	if (msg->data[1] != CEVTIND_CHIP_SJA1000) {
1044		netdev_err(mod->ndev, "unable to handle errors on non-SJA1000\n");
1045		return -ENODEV;
1046	}
1047
1048	/* check the message length for sanity */
1049	if (le16_to_cpu(msg->len) < 6) {
1050		netdev_err(mod->ndev, "error message too short\n");
1051		return -EINVAL;
1052	}
1053
1054	isrc = msg->data[0];
1055	ecc = msg->data[2];
1056	status = msg->data[3];
1057	rxerr = msg->data[4];
1058	txerr = msg->data[5];
1059
1060	/*
1061	 * This hardware lacks any support other than bus error messages to
1062	 * determine if packet transmission has failed.
1063	 *
1064	 * When TX errors happen, one echo skb needs to be dropped from the
1065	 * front of the queue.
1066	 *
1067	 * A small bit of code is duplicated here and below, to avoid error
1068	 * skb allocation when it will just be freed immediately.
1069	 */
1070	if (isrc == CEVTIND_BEI) {
1071		int ret;
1072		netdev_dbg(mod->ndev, "bus error interrupt\n");
1073
1074		/* TX error */
1075		if (!(ecc & ECC_DIR)) {
1076			kfree_skb(skb_dequeue(&mod->echoq));
1077			stats->tx_errors++;
1078		} else {
1079			stats->rx_errors++;
1080		}
1081
1082		/*
1083		 * The controller automatically disables bus-error interrupts
1084		 * and therefore we must re-enable them.
1085		 */
1086		ret = ican3_set_buserror(mod, 1);
1087		if (ret) {
1088			netdev_err(mod->ndev, "unable to re-enable bus-error\n");
1089			return ret;
1090		}
1091
1092		/* bus error reporting is off, return immediately */
1093		if (!(mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1094			return 0;
1095	}
1096
1097	skb = alloc_can_err_skb(dev, &cf);
1098	if (skb == NULL)
1099		return -ENOMEM;
1100
1101	/* data overrun interrupt */
1102	if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) {
1103		netdev_dbg(mod->ndev, "data overrun interrupt\n");
1104		cf->can_id |= CAN_ERR_CRTL;
1105		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
1106		stats->rx_over_errors++;
1107		stats->rx_errors++;
1108	}
1109
1110	/* error warning + passive interrupt */
1111	if (isrc == CEVTIND_EI) {
1112		netdev_dbg(mod->ndev, "error warning + passive interrupt\n");
1113		if (status & SR_BS) {
1114			state = CAN_STATE_BUS_OFF;
1115			cf->can_id |= CAN_ERR_BUSOFF;
1116			mod->can.can_stats.bus_off++;
1117			can_bus_off(dev);
1118		} else if (status & SR_ES) {
1119			if (rxerr >= 128 || txerr >= 128)
1120				state = CAN_STATE_ERROR_PASSIVE;
1121			else
1122				state = CAN_STATE_ERROR_WARNING;
1123		} else {
1124			state = CAN_STATE_ERROR_ACTIVE;
1125		}
1126	}
1127
1128	/* bus error interrupt */
1129	if (isrc == CEVTIND_BEI) {
1130		mod->can.can_stats.bus_error++;
1131		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR | CAN_ERR_CNT;
1132
1133		switch (ecc & ECC_MASK) {
1134		case ECC_BIT:
1135			cf->data[2] |= CAN_ERR_PROT_BIT;
1136			break;
1137		case ECC_FORM:
1138			cf->data[2] |= CAN_ERR_PROT_FORM;
1139			break;
1140		case ECC_STUFF:
1141			cf->data[2] |= CAN_ERR_PROT_STUFF;
1142			break;
1143		default:
1144			cf->data[3] = ecc & ECC_SEG;
1145			break;
1146		}
1147
1148		if (!(ecc & ECC_DIR))
1149			cf->data[2] |= CAN_ERR_PROT_TX;
1150
1151		cf->data[6] = txerr;
1152		cf->data[7] = rxerr;
1153	}
1154
1155	if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING ||
1156					state == CAN_STATE_ERROR_PASSIVE)) {
1157		cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
1158		if (state == CAN_STATE_ERROR_WARNING) {
1159			mod->can.can_stats.error_warning++;
1160			cf->data[1] = (txerr > rxerr) ?
1161				CAN_ERR_CRTL_TX_WARNING :
1162				CAN_ERR_CRTL_RX_WARNING;
1163		} else {
1164			mod->can.can_stats.error_passive++;
1165			cf->data[1] = (txerr > rxerr) ?
1166				CAN_ERR_CRTL_TX_PASSIVE :
1167				CAN_ERR_CRTL_RX_PASSIVE;
1168		}
1169
1170		cf->data[6] = txerr;
1171		cf->data[7] = rxerr;
1172	}
1173
1174	mod->can.state = state;
1175	netif_rx(skb);
1176	return 0;
1177}
1178
1179static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg)
1180{
1181	switch (msg->data[0]) {
1182	case INQUIRY_STATUS:
1183	case INQUIRY_EXTENDED:
1184		mod->bec.rxerr = msg->data[5];
1185		mod->bec.txerr = msg->data[6];
1186		complete(&mod->buserror_comp);
1187		break;
1188	case INQUIRY_TERMINATION:
1189		mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON;
1190		complete(&mod->termination_comp);
1191		break;
1192	default:
1193		netdev_err(mod->ndev, "received an unknown inquiry response\n");
1194		break;
1195	}
1196}
1197
1198/* Handle NMTS Slave Event Indication Messages from the firmware */
1199static void ican3_handle_nmtsind(struct ican3_dev *mod, struct ican3_msg *msg)
1200{
1201	u16 subspec;
1202
1203	subspec = msg->data[0] + msg->data[1] * 0x100;
1204	if (subspec == NMTS_SLAVE_EVENT_IND) {
1205		switch (msg->data[2]) {
1206		case NE_LOCAL_OCCURRED:
1207		case NE_LOCAL_RESOLVED:
1208			/* now follows the same message as Raw ICANOS CEVTIND
1209			 * shift the data at the same place and call this method
1210			 */
1211			le16_add_cpu(&msg->len, -3);
1212			memmove(msg->data, msg->data + 3, le16_to_cpu(msg->len));
1213			ican3_handle_cevtind(mod, msg);
1214			break;
1215		case NE_REMOTE_OCCURRED:
1216		case NE_REMOTE_RESOLVED:
1217			/* should not occurre, ignore */
1218			break;
1219		default:
1220			netdev_warn(mod->ndev, "unknown NMTS event indication %x\n",
1221				    msg->data[2]);
1222			break;
1223		}
1224	} else if (subspec == NMTS_SLAVE_STATE_IND) {
1225		/* ignore state indications */
1226	} else {
1227		netdev_warn(mod->ndev, "unhandled NMTS indication %x\n",
1228			    subspec);
1229		return;
1230	}
1231}
1232
1233static void ican3_handle_unknown_message(struct ican3_dev *mod,
1234					struct ican3_msg *msg)
1235{
1236	netdev_warn(mod->ndev, "received unknown message: spec 0x%.2x length %d\n",
1237			   msg->spec, le16_to_cpu(msg->len));
1238}
1239
1240/*
1241 * Handle a control message from the firmware
1242 */
1243static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg)
1244{
1245	netdev_dbg(mod->ndev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__,
1246			   mod->num, msg->spec, le16_to_cpu(msg->len));
1247
1248	switch (msg->spec) {
1249	case MSG_IDVERS:
1250		ican3_handle_idvers(mod, msg);
1251		break;
1252	case MSG_MSGLOST:
1253	case MSG_FMSGLOST:
1254		ican3_handle_msglost(mod, msg);
1255		break;
1256	case MSG_CEVTIND:
1257		ican3_handle_cevtind(mod, msg);
1258		break;
1259	case MSG_INQUIRY:
1260		ican3_handle_inquiry(mod, msg);
1261		break;
1262	case MSG_NMTS:
1263		ican3_handle_nmtsind(mod, msg);
1264		break;
1265	default:
1266		ican3_handle_unknown_message(mod, msg);
1267		break;
1268	}
1269}
1270
1271/*
1272 * The ican3 needs to store all echo skbs, and therefore cannot
1273 * use the generic infrastructure for this.
1274 */
1275static void ican3_put_echo_skb(struct ican3_dev *mod, struct sk_buff *skb)
1276{
1277	skb = can_create_echo_skb(skb);
1278	if (!skb)
1279		return;
1280
1281	skb_tx_timestamp(skb);
1282
1283	/* save this skb for tx interrupt echo handling */
1284	skb_queue_tail(&mod->echoq, skb);
1285}
1286
1287static unsigned int ican3_get_echo_skb(struct ican3_dev *mod)
1288{
1289	struct sk_buff *skb = skb_dequeue(&mod->echoq);
1290	struct can_frame *cf;
1291	u8 dlc = 0;
1292
1293	/* this should never trigger unless there is a driver bug */
1294	if (!skb) {
1295		netdev_err(mod->ndev, "BUG: echo skb not occupied\n");
1296		return 0;
1297	}
1298
1299	cf = (struct can_frame *)skb->data;
1300	if (!(cf->can_id & CAN_RTR_FLAG))
1301		dlc = cf->len;
1302
1303	/* check flag whether this packet has to be looped back */
1304	if (skb->pkt_type != PACKET_LOOPBACK) {
1305		kfree_skb(skb);
1306		return dlc;
1307	}
1308
1309	skb->protocol = htons(ETH_P_CAN);
1310	skb->pkt_type = PACKET_BROADCAST;
1311	skb->ip_summed = CHECKSUM_UNNECESSARY;
1312	skb->dev = mod->ndev;
1313	netif_receive_skb(skb);
1314	return dlc;
1315}
1316
1317/*
1318 * Compare an skb with an existing echo skb
1319 *
1320 * This function will be used on devices which have a hardware loopback.
1321 * On these devices, this function can be used to compare a received skb
1322 * with the saved echo skbs so that the hardware echo skb can be dropped.
1323 *
1324 * Returns true if the skb's are identical, false otherwise.
1325 */
1326static bool ican3_echo_skb_matches(struct ican3_dev *mod, struct sk_buff *skb)
1327{
1328	struct can_frame *cf = (struct can_frame *)skb->data;
1329	struct sk_buff *echo_skb = skb_peek(&mod->echoq);
1330	struct can_frame *echo_cf;
1331
1332	if (!echo_skb)
1333		return false;
1334
1335	echo_cf = (struct can_frame *)echo_skb->data;
1336	if (cf->can_id != echo_cf->can_id)
1337		return false;
1338
1339	if (cf->len != echo_cf->len)
1340		return false;
1341
1342	return memcmp(cf->data, echo_cf->data, cf->len) == 0;
1343}
1344
1345/*
1346 * Check that there is room in the TX ring to transmit another skb
1347 *
1348 * LOCKING: must hold mod->lock
1349 */
1350static bool ican3_txok(struct ican3_dev *mod)
1351{
1352	struct ican3_fast_desc __iomem *desc;
1353	u8 control;
1354
1355	/* check that we have echo queue space */
1356	if (skb_queue_len(&mod->echoq) >= ICAN3_TX_BUFFERS)
1357		return false;
1358
1359	/* copy the control bits of the descriptor */
1360	ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16));
1361	desc = mod->dpm + ((mod->fasttx_num % 16) * sizeof(*desc));
1362	control = ioread8(&desc->control);
1363
1364	/* if the control bits are not valid, then we have no more space */
1365	if (!(control & DESC_VALID))
1366		return false;
1367
1368	return true;
1369}
1370
1371/*
1372 * Receive one CAN frame from the hardware
1373 *
1374 * CONTEXT: must be called from user context
1375 */
1376static int ican3_recv_skb(struct ican3_dev *mod)
1377{
1378	struct net_device *ndev = mod->ndev;
1379	struct net_device_stats *stats = &ndev->stats;
1380	struct ican3_fast_desc desc;
1381	void __iomem *desc_addr;
1382	struct can_frame *cf;
1383	struct sk_buff *skb;
1384	unsigned long flags;
1385
1386	spin_lock_irqsave(&mod->lock, flags);
1387
1388	/* copy the whole descriptor */
1389	ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16));
1390	desc_addr = mod->dpm + ((mod->fastrx_num % 16) * sizeof(desc));
1391	memcpy_fromio(&desc, desc_addr, sizeof(desc));
1392
1393	spin_unlock_irqrestore(&mod->lock, flags);
1394
1395	/* check that we actually have a CAN frame */
1396	if (!(desc.control & DESC_VALID))
1397		return -ENOBUFS;
1398
1399	/* allocate an skb */
1400	skb = alloc_can_skb(ndev, &cf);
1401	if (unlikely(skb == NULL)) {
1402		stats->rx_dropped++;
1403		goto err_noalloc;
1404	}
1405
1406	/* convert the ICAN3 frame into Linux CAN format */
1407	ican3_to_can_frame(mod, &desc, cf);
1408
1409	/*
1410	 * If this is an ECHO frame received from the hardware loopback
1411	 * feature, use the skb saved in the ECHO stack instead. This allows
1412	 * the Linux CAN core to support CAN_RAW_RECV_OWN_MSGS correctly.
1413	 *
1414	 * Since this is a confirmation of a successfully transmitted packet
1415	 * sent from this host, update the transmit statistics.
1416	 *
1417	 * Also, the netdevice queue needs to be allowed to send packets again.
1418	 */
1419	if (ican3_echo_skb_matches(mod, skb)) {
1420		stats->tx_packets++;
1421		stats->tx_bytes += ican3_get_echo_skb(mod);
1422		kfree_skb(skb);
1423		goto err_noalloc;
1424	}
1425
1426	/* update statistics, receive the skb */
1427	stats->rx_packets++;
1428	if (!(cf->can_id & CAN_RTR_FLAG))
1429		stats->rx_bytes += cf->len;
1430	netif_receive_skb(skb);
1431
1432err_noalloc:
1433	/* toggle the valid bit and return the descriptor to the ring */
1434	desc.control ^= DESC_VALID;
1435
1436	spin_lock_irqsave(&mod->lock, flags);
1437
1438	ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16));
1439	memcpy_toio(desc_addr, &desc, 1);
1440
1441	/* update the next buffer pointer */
1442	mod->fastrx_num = (desc.control & DESC_WRAP) ? 0
1443						     : (mod->fastrx_num + 1);
1444
1445	/* there are still more buffers to process */
1446	spin_unlock_irqrestore(&mod->lock, flags);
1447	return 0;
1448}
1449
1450static int ican3_napi(struct napi_struct *napi, int budget)
1451{
1452	struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi);
1453	unsigned long flags;
1454	int received = 0;
1455	int ret;
1456
1457	/* process all communication messages */
1458	while (true) {
1459		struct ican3_msg msg;
1460		ret = ican3_recv_msg(mod, &msg);
1461		if (ret)
1462			break;
1463
1464		ican3_handle_message(mod, &msg);
1465	}
1466
1467	/* process all CAN frames from the fast interface */
1468	while (received < budget) {
1469		ret = ican3_recv_skb(mod);
1470		if (ret)
1471			break;
1472
1473		received++;
1474	}
1475
1476	/* We have processed all packets that the adapter had, but it
1477	 * was less than our budget, stop polling */
1478	if (received < budget)
1479		napi_complete_done(napi, received);
1480
1481	spin_lock_irqsave(&mod->lock, flags);
1482
1483	/* Wake up the transmit queue if necessary */
1484	if (netif_queue_stopped(mod->ndev) && ican3_txok(mod))
1485		netif_wake_queue(mod->ndev);
1486
1487	spin_unlock_irqrestore(&mod->lock, flags);
1488
1489	/* re-enable interrupt generation */
1490	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1491	return received;
1492}
1493
1494static irqreturn_t ican3_irq(int irq, void *dev_id)
1495{
1496	struct ican3_dev *mod = dev_id;
1497	u8 stat;
1498
1499	/*
1500	 * The interrupt status register on this device reports interrupts
1501	 * as zeroes instead of using ones like most other devices
1502	 */
1503	stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num);
1504	if (stat == (1 << mod->num))
1505		return IRQ_NONE;
1506
1507	/* clear the MODULbus interrupt from the microcontroller */
1508	ioread8(&mod->dpmctrl->interrupt);
1509
1510	/* disable interrupt generation, schedule the NAPI poller */
1511	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1512	napi_schedule(&mod->napi);
1513	return IRQ_HANDLED;
1514}
1515
1516/*
1517 * Firmware reset, startup, and shutdown
1518 */
1519
1520/*
1521 * Reset an ICAN module to its power-on state
1522 *
1523 * CONTEXT: no network device registered
1524 */
1525static int ican3_reset_module(struct ican3_dev *mod)
1526{
1527	unsigned long start;
1528	u8 runold, runnew;
1529
1530	/* disable interrupts so no more work is scheduled */
1531	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1532
1533	/* the first unallocated page in the DPM is #9 */
1534	mod->free_page = DPM_FREE_START;
1535
1536	ican3_set_page(mod, QUEUE_OLD_CONTROL);
1537	runold = ioread8(mod->dpm + TARGET_RUNNING);
1538
1539	/* reset the module */
1540	iowrite8(0x00, &mod->dpmctrl->hwreset);
1541
1542	/* wait until the module has finished resetting and is running */
1543	start = jiffies;
1544	do {
1545		ican3_set_page(mod, QUEUE_OLD_CONTROL);
1546		runnew = ioread8(mod->dpm + TARGET_RUNNING);
1547		if (runnew == (runold ^ 0xff))
1548			return 0;
1549
1550		msleep(10);
1551	} while (time_before(jiffies, start + HZ / 2));
1552
1553	netdev_err(mod->ndev, "failed to reset CAN module\n");
1554	return -ETIMEDOUT;
1555}
1556
1557static void ican3_shutdown_module(struct ican3_dev *mod)
1558{
1559	ican3_msg_disconnect(mod);
1560	ican3_reset_module(mod);
1561}
1562
1563/*
1564 * Startup an ICAN module, bringing it into fast mode
1565 */
1566static int ican3_startup_module(struct ican3_dev *mod)
1567{
1568	int ret;
1569
1570	ret = ican3_reset_module(mod);
1571	if (ret) {
1572		netdev_err(mod->ndev, "unable to reset module\n");
1573		return ret;
1574	}
1575
1576	/* detect firmware */
1577	memcpy_fromio(mod->fwinfo, mod->dpm + FIRMWARE_STAMP, sizeof(mod->fwinfo) - 1);
1578	if (strncmp(mod->fwinfo, "JANZ-ICAN3", 10)) {
1579		netdev_err(mod->ndev, "ICAN3 not detected (found %s)\n", mod->fwinfo);
1580		return -ENODEV;
1581	}
1582	if (strstr(mod->fwinfo, "CAL/CANopen"))
1583		mod->fwtype = ICAN3_FWTYPE_CAL_CANOPEN;
1584	else
1585		mod->fwtype = ICAN3_FWTYPE_ICANOS;
1586
1587	/* re-enable interrupts so we can send messages */
1588	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1589
1590	ret = ican3_msg_connect(mod);
1591	if (ret) {
1592		netdev_err(mod->ndev, "unable to connect to module\n");
1593		return ret;
1594	}
1595
1596	ican3_init_new_host_interface(mod);
1597	ret = ican3_msg_newhostif(mod);
1598	if (ret) {
1599		netdev_err(mod->ndev, "unable to switch to new-style interface\n");
1600		return ret;
1601	}
1602
1603	/* default to "termination on" */
1604	ret = ican3_set_termination(mod, true);
1605	if (ret) {
1606		netdev_err(mod->ndev, "unable to enable termination\n");
1607		return ret;
1608	}
1609
1610	/* default to "bus errors enabled" */
1611	ret = ican3_set_buserror(mod, 1);
1612	if (ret) {
1613		netdev_err(mod->ndev, "unable to set bus-error\n");
1614		return ret;
1615	}
1616
1617	ican3_init_fast_host_interface(mod);
1618	ret = ican3_msg_fasthostif(mod);
1619	if (ret) {
1620		netdev_err(mod->ndev, "unable to switch to fast host interface\n");
1621		return ret;
1622	}
1623
1624	ret = ican3_set_id_filter(mod, true);
1625	if (ret) {
1626		netdev_err(mod->ndev, "unable to set acceptance filter\n");
1627		return ret;
1628	}
1629
1630	return 0;
1631}
1632
1633/*
1634 * CAN Network Device
1635 */
1636
1637static int ican3_open(struct net_device *ndev)
1638{
1639	struct ican3_dev *mod = netdev_priv(ndev);
1640	int ret;
1641
1642	/* open the CAN layer */
1643	ret = open_candev(ndev);
1644	if (ret) {
1645		netdev_err(mod->ndev, "unable to start CAN layer\n");
1646		return ret;
1647	}
1648
1649	/* bring the bus online */
1650	ret = ican3_set_bus_state(mod, true);
1651	if (ret) {
1652		netdev_err(mod->ndev, "unable to set bus-on\n");
1653		close_candev(ndev);
1654		return ret;
1655	}
1656
1657	/* start up the network device */
1658	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1659	netif_start_queue(ndev);
1660
1661	return 0;
1662}
1663
1664static int ican3_stop(struct net_device *ndev)
1665{
1666	struct ican3_dev *mod = netdev_priv(ndev);
1667	int ret;
1668
1669	/* stop the network device xmit routine */
1670	netif_stop_queue(ndev);
1671	mod->can.state = CAN_STATE_STOPPED;
1672
1673	/* bring the bus offline, stop receiving packets */
1674	ret = ican3_set_bus_state(mod, false);
1675	if (ret) {
1676		netdev_err(mod->ndev, "unable to set bus-off\n");
1677		return ret;
1678	}
1679
1680	/* drop all outstanding echo skbs */
1681	skb_queue_purge(&mod->echoq);
1682
1683	/* close the CAN layer */
1684	close_candev(ndev);
1685	return 0;
1686}
1687
1688static netdev_tx_t ican3_xmit(struct sk_buff *skb, struct net_device *ndev)
1689{
1690	struct ican3_dev *mod = netdev_priv(ndev);
1691	struct can_frame *cf = (struct can_frame *)skb->data;
1692	struct ican3_fast_desc desc;
1693	void __iomem *desc_addr;
1694	unsigned long flags;
1695
1696	if (can_dev_dropped_skb(ndev, skb))
1697		return NETDEV_TX_OK;
1698
1699	spin_lock_irqsave(&mod->lock, flags);
1700
1701	/* check that we can actually transmit */
1702	if (!ican3_txok(mod)) {
1703		netdev_err(mod->ndev, "BUG: no free descriptors\n");
1704		spin_unlock_irqrestore(&mod->lock, flags);
1705		return NETDEV_TX_BUSY;
1706	}
1707
1708	/* copy the control bits of the descriptor */
1709	ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16));
1710	desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc));
1711	memset(&desc, 0, sizeof(desc));
1712	memcpy_fromio(&desc, desc_addr, 1);
1713
1714	/* convert the Linux CAN frame into ICAN3 format */
1715	can_frame_to_ican3(mod, cf, &desc);
1716
1717	/*
1718	 * This hardware doesn't have TX-done notifications, so we'll try and
1719	 * emulate it the best we can using ECHO skbs. Add the skb to the ECHO
1720	 * stack. Upon packet reception, check if the ECHO skb and received
1721	 * skb match, and use that to wake the queue.
1722	 */
1723	ican3_put_echo_skb(mod, skb);
1724
1725	/*
1726	 * the programming manual says that you must set the IVALID bit, then
1727	 * interrupt, then set the valid bit. Quite weird, but it seems to be
1728	 * required for this to work
1729	 */
1730	desc.control |= DESC_IVALID;
1731	memcpy_toio(desc_addr, &desc, sizeof(desc));
1732
1733	/* generate a MODULbus interrupt to the microcontroller */
1734	iowrite8(0x01, &mod->dpmctrl->interrupt);
1735
1736	desc.control ^= DESC_VALID;
1737	memcpy_toio(desc_addr, &desc, sizeof(desc));
1738
1739	/* update the next buffer pointer */
1740	mod->fasttx_num = (desc.control & DESC_WRAP) ? 0
1741						     : (mod->fasttx_num + 1);
1742
1743	/* if there is no free descriptor space, stop the transmit queue */
1744	if (!ican3_txok(mod))
1745		netif_stop_queue(ndev);
1746
1747	spin_unlock_irqrestore(&mod->lock, flags);
1748	return NETDEV_TX_OK;
1749}
1750
1751static const struct net_device_ops ican3_netdev_ops = {
1752	.ndo_open	= ican3_open,
1753	.ndo_stop	= ican3_stop,
1754	.ndo_start_xmit	= ican3_xmit,
1755	.ndo_change_mtu = can_change_mtu,
1756};
1757
1758static const struct ethtool_ops ican3_ethtool_ops = {
1759	.get_ts_info = ethtool_op_get_ts_info,
1760};
1761
1762/*
1763 * Low-level CAN Device
1764 */
1765
1766/* This structure was stolen from drivers/net/can/sja1000/sja1000.c */
1767static const struct can_bittiming_const ican3_bittiming_const = {
1768	.name = DRV_NAME,
1769	.tseg1_min = 1,
1770	.tseg1_max = 16,
1771	.tseg2_min = 1,
1772	.tseg2_max = 8,
1773	.sjw_max = 4,
1774	.brp_min = 1,
1775	.brp_max = 64,
1776	.brp_inc = 1,
1777};
1778
1779static int ican3_set_mode(struct net_device *ndev, enum can_mode mode)
1780{
1781	struct ican3_dev *mod = netdev_priv(ndev);
1782	int ret;
1783
1784	if (mode != CAN_MODE_START)
1785		return -ENOTSUPP;
1786
1787	/* bring the bus online */
1788	ret = ican3_set_bus_state(mod, true);
1789	if (ret) {
1790		netdev_err(ndev, "unable to set bus-on\n");
1791		return ret;
1792	}
1793
1794	/* start up the network device */
1795	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1796
1797	if (netif_queue_stopped(ndev))
1798		netif_wake_queue(ndev);
1799
1800	return 0;
1801}
1802
1803static int ican3_get_berr_counter(const struct net_device *ndev,
1804				  struct can_berr_counter *bec)
1805{
1806	struct ican3_dev *mod = netdev_priv(ndev);
1807	int ret;
1808
1809	ret = ican3_send_inquiry(mod, INQUIRY_STATUS);
1810	if (ret)
1811		return ret;
1812
1813	if (!wait_for_completion_timeout(&mod->buserror_comp, HZ)) {
1814		netdev_info(mod->ndev, "%s timed out\n", __func__);
1815		return -ETIMEDOUT;
1816	}
1817
1818	bec->rxerr = mod->bec.rxerr;
1819	bec->txerr = mod->bec.txerr;
1820	return 0;
1821}
1822
1823/*
1824 * Sysfs Attributes
1825 */
1826
1827static ssize_t termination_show(struct device *dev,
1828				struct device_attribute *attr,
1829				char *buf)
1830{
1831	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1832	int ret;
1833
1834	ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION);
1835	if (ret)
1836		return ret;
1837
1838	if (!wait_for_completion_timeout(&mod->termination_comp, HZ)) {
1839		netdev_info(mod->ndev, "%s timed out\n", __func__);
1840		return -ETIMEDOUT;
1841	}
1842
1843	return sysfs_emit(buf, "%u\n", mod->termination_enabled);
1844}
1845
1846static ssize_t termination_store(struct device *dev,
1847				 struct device_attribute *attr,
1848				 const char *buf, size_t count)
1849{
1850	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1851	unsigned long enable;
1852	int ret;
1853
1854	if (kstrtoul(buf, 0, &enable))
1855		return -EINVAL;
1856
1857	ret = ican3_set_termination(mod, enable);
1858	if (ret)
1859		return ret;
1860
1861	return count;
1862}
1863
1864static ssize_t fwinfo_show(struct device *dev,
1865			   struct device_attribute *attr,
1866			   char *buf)
1867{
1868	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1869
1870	return scnprintf(buf, PAGE_SIZE, "%s\n", mod->fwinfo);
1871}
1872
1873static DEVICE_ATTR_RW(termination);
1874static DEVICE_ATTR_RO(fwinfo);
 
1875
1876static struct attribute *ican3_sysfs_attrs[] = {
1877	&dev_attr_termination.attr,
1878	&dev_attr_fwinfo.attr,
1879	NULL,
1880};
1881
1882static const struct attribute_group ican3_sysfs_attr_group = {
1883	.attrs = ican3_sysfs_attrs,
1884};
1885
1886/*
1887 * PCI Subsystem
1888 */
1889
1890static int ican3_probe(struct platform_device *pdev)
1891{
1892	struct janz_platform_data *pdata;
1893	struct net_device *ndev;
1894	struct ican3_dev *mod;
1895	struct resource *res;
1896	struct device *dev;
1897	int ret;
1898
1899	pdata = dev_get_platdata(&pdev->dev);
1900	if (!pdata)
1901		return -ENXIO;
1902
1903	dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno);
1904
1905	/* save the struct device for printing */
1906	dev = &pdev->dev;
1907
1908	/* allocate the CAN device and private data */
1909	ndev = alloc_candev(sizeof(*mod), 0);
1910	if (!ndev) {
1911		dev_err(dev, "unable to allocate CANdev\n");
1912		ret = -ENOMEM;
1913		goto out_return;
1914	}
1915
1916	platform_set_drvdata(pdev, ndev);
1917	mod = netdev_priv(ndev);
1918	mod->ndev = ndev;
1919	mod->num = pdata->modno;
1920	netif_napi_add_weight(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS);
1921	skb_queue_head_init(&mod->echoq);
1922	spin_lock_init(&mod->lock);
1923	init_completion(&mod->termination_comp);
1924	init_completion(&mod->buserror_comp);
1925
1926	/* setup device-specific sysfs attributes */
1927	ndev->sysfs_groups[0] = &ican3_sysfs_attr_group;
1928
1929	/* the first unallocated page in the DPM is 9 */
1930	mod->free_page = DPM_FREE_START;
1931
1932	ndev->netdev_ops = &ican3_netdev_ops;
1933	ndev->ethtool_ops = &ican3_ethtool_ops;
1934	ndev->flags |= IFF_ECHO;
1935	SET_NETDEV_DEV(ndev, &pdev->dev);
1936
1937	mod->can.clock.freq = ICAN3_CAN_CLOCK;
1938	mod->can.bittiming_const = &ican3_bittiming_const;
1939	mod->can.do_set_mode = ican3_set_mode;
1940	mod->can.do_get_berr_counter = ican3_get_berr_counter;
1941	mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES
1942				    | CAN_CTRLMODE_BERR_REPORTING
1943				    | CAN_CTRLMODE_ONE_SHOT;
1944
1945	/* find our IRQ number */
1946	mod->irq = platform_get_irq(pdev, 0);
1947	if (mod->irq < 0) {
1948		ret = -ENODEV;
1949		goto out_free_ndev;
1950	}
1951
1952	ndev->irq = mod->irq;
1953
1954	/* get access to the MODULbus registers for this module */
1955	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1956	if (!res) {
1957		dev_err(dev, "MODULbus registers not found\n");
1958		ret = -ENODEV;
1959		goto out_free_ndev;
1960	}
1961
1962	mod->dpm = ioremap(res->start, resource_size(res));
1963	if (!mod->dpm) {
1964		dev_err(dev, "MODULbus registers not ioremap\n");
1965		ret = -ENOMEM;
1966		goto out_free_ndev;
1967	}
1968
1969	mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE;
1970
1971	/* get access to the control registers for this module */
1972	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1973	if (!res) {
1974		dev_err(dev, "CONTROL registers not found\n");
1975		ret = -ENODEV;
1976		goto out_iounmap_dpm;
1977	}
1978
1979	mod->ctrl = ioremap(res->start, resource_size(res));
1980	if (!mod->ctrl) {
1981		dev_err(dev, "CONTROL registers not ioremap\n");
1982		ret = -ENOMEM;
1983		goto out_iounmap_dpm;
1984	}
1985
1986	/* disable our IRQ, then hookup the IRQ handler */
1987	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1988	ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod);
1989	if (ret) {
1990		dev_err(dev, "unable to request IRQ\n");
1991		goto out_iounmap_ctrl;
1992	}
1993
1994	/* reset and initialize the CAN controller into fast mode */
1995	napi_enable(&mod->napi);
1996	ret = ican3_startup_module(mod);
1997	if (ret) {
1998		dev_err(dev, "%s: unable to start CANdev\n", __func__);
1999		goto out_free_irq;
2000	}
2001
2002	/* register with the Linux CAN layer */
2003	ret = register_candev(ndev);
2004	if (ret) {
2005		dev_err(dev, "%s: unable to register CANdev\n", __func__);
2006		goto out_free_irq;
2007	}
2008
2009	netdev_info(mod->ndev, "module %d: registered CAN device\n", pdata->modno);
2010	return 0;
2011
2012out_free_irq:
2013	napi_disable(&mod->napi);
2014	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
2015	free_irq(mod->irq, mod);
2016out_iounmap_ctrl:
2017	iounmap(mod->ctrl);
2018out_iounmap_dpm:
2019	iounmap(mod->dpm);
2020out_free_ndev:
2021	free_candev(ndev);
2022out_return:
2023	return ret;
2024}
2025
2026static void ican3_remove(struct platform_device *pdev)
2027{
2028	struct net_device *ndev = platform_get_drvdata(pdev);
2029	struct ican3_dev *mod = netdev_priv(ndev);
2030
2031	/* unregister the netdevice, stop interrupts */
2032	unregister_netdev(ndev);
2033	napi_disable(&mod->napi);
2034	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
2035	free_irq(mod->irq, mod);
2036
2037	/* put the module into reset */
2038	ican3_shutdown_module(mod);
2039
2040	/* unmap all registers */
2041	iounmap(mod->ctrl);
2042	iounmap(mod->dpm);
2043
2044	free_candev(ndev);
 
 
2045}
2046
2047static struct platform_driver ican3_driver = {
2048	.driver		= {
2049		.name	= DRV_NAME,
2050	},
2051	.probe		= ican3_probe,
2052	.remove		= ican3_remove,
2053};
2054
2055module_platform_driver(ican3_driver);
2056
2057MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
2058MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver");
2059MODULE_LICENSE("GPL");
2060MODULE_ALIAS("platform:janz-ican3");