xref: /linux/drivers/net/can/janz-ican3.c (revision 2d78eb0342dd2c9c5cde9ae9ada1d33f189a858b)
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 */
185 enum 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 */
194 struct 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 
214 struct 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 
273 struct ican3_msg {
274 	u8 control;
275 	u8 spec;
276 	__le16 len;
277 	u8 data[252];
278 };
279 
280 struct ican3_new_desc {
281 	u8 control;
282 	u8 pointer;
283 };
284 
285 struct ican3_fast_desc {
286 	u8 control;
287 	u8 command;
288 	u8 data[14];
289 };
290 
291 /* write to the window basic address register */
292 static 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  */
309 static 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  */
354 static 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 
391 static 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 
470 static 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  */
558 static 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  */
589 static 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 
621 static 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 
637 static 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 
657 static 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 
668 static 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 
679 static 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 
700 static 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  */
733 static 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  */
777 static 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 
856 static 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 
869 static 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 
882 static 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 
910 static 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 
942 static 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  */
986 static 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 
991 static 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  */
1033 static 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 
1179 static 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 */
1199 static 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 
1233 static 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  */
1243 static 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  */
1275 static 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 
1287 static 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  */
1326 static 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  */
1350 static 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  */
1376 static 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 
1432 err_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 
1450 static 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 
1494 static 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  */
1525 static 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 
1557 static 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  */
1566 static 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 
1637 static 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 
1664 static 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 
1688 static 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 
1751 static 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 
1758 static 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 */
1767 static 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 
1779 static 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 
1803 static 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 
1827 static 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 
1846 static 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 
1864 static 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 
1873 static DEVICE_ATTR_RW(termination);
1874 static DEVICE_ATTR_RO(fwinfo);
1875 
1876 static struct attribute *ican3_sysfs_attrs[] = {
1877 	&dev_attr_termination.attr,
1878 	&dev_attr_fwinfo.attr,
1879 	NULL,
1880 };
1881 
1882 static const struct attribute_group ican3_sysfs_attr_group = {
1883 	.attrs = ican3_sysfs_attrs,
1884 };
1885 
1886 /*
1887  * PCI Subsystem
1888  */
1889 
1890 static 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 
2012 out_free_irq:
2013 	napi_disable(&mod->napi);
2014 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
2015 	free_irq(mod->irq, mod);
2016 out_iounmap_ctrl:
2017 	iounmap(mod->ctrl);
2018 out_iounmap_dpm:
2019 	iounmap(mod->dpm);
2020 out_free_ndev:
2021 	free_candev(ndev);
2022 out_return:
2023 	return ret;
2024 }
2025 
2026 static int 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 	return 0;
2047 }
2048 
2049 static struct platform_driver ican3_driver = {
2050 	.driver		= {
2051 		.name	= DRV_NAME,
2052 	},
2053 	.probe		= ican3_probe,
2054 	.remove		= ican3_remove,
2055 };
2056 
2057 module_platform_driver(ican3_driver);
2058 
2059 MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
2060 MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver");
2061 MODULE_LICENSE("GPL");
2062 MODULE_ALIAS("platform:janz-ican3");
2063