xref: /openbmc/linux/drivers/net/can/janz-ican3.c (revision 4f6cce39)
1 /*
2  * Janz MODULbus VMOD-ICAN3 CAN Interface Driver
3  *
4  * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2 of the License, or (at your
9  * option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
15 #include <linux/delay.h>
16 #include <linux/platform_device.h>
17 
18 #include <linux/netdevice.h>
19 #include <linux/can.h>
20 #include <linux/can/dev.h>
21 #include <linux/can/skb.h>
22 #include <linux/can/error.h>
23 
24 #include <linux/mfd/janz.h>
25 #include <asm/io.h>
26 
27 /* the DPM has 64k of memory, organized into 256x 256 byte pages */
28 #define DPM_NUM_PAGES		256
29 #define DPM_PAGE_SIZE		256
30 #define DPM_PAGE_ADDR(p)	((p) * DPM_PAGE_SIZE)
31 
32 /* JANZ ICAN3 "old-style" host interface queue page numbers */
33 #define QUEUE_OLD_CONTROL	0
34 #define QUEUE_OLD_RB0		1
35 #define QUEUE_OLD_RB1		2
36 #define QUEUE_OLD_WB0		3
37 #define QUEUE_OLD_WB1		4
38 
39 /* Janz ICAN3 "old-style" host interface control registers */
40 #define MSYNC_PEER		0x00		/* ICAN only */
41 #define MSYNC_LOCL		0x01		/* host only */
42 #define TARGET_RUNNING		0x02
43 #define FIRMWARE_STAMP		0x60		/* big endian firmware stamp */
44 
45 #define MSYNC_RB0		0x01
46 #define MSYNC_RB1		0x02
47 #define MSYNC_RBLW		0x04
48 #define MSYNC_RB_MASK		(MSYNC_RB0 | MSYNC_RB1)
49 
50 #define MSYNC_WB0		0x10
51 #define MSYNC_WB1		0x20
52 #define MSYNC_WBLW		0x40
53 #define MSYNC_WB_MASK		(MSYNC_WB0 | MSYNC_WB1)
54 
55 /* Janz ICAN3 "new-style" host interface queue page numbers */
56 #define QUEUE_TOHOST		5
57 #define QUEUE_FROMHOST_MID	6
58 #define QUEUE_FROMHOST_HIGH	7
59 #define QUEUE_FROMHOST_LOW	8
60 
61 /* The first free page in the DPM is #9 */
62 #define DPM_FREE_START		9
63 
64 /* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */
65 #define DESC_VALID		0x80
66 #define DESC_WRAP		0x40
67 #define DESC_INTERRUPT		0x20
68 #define DESC_IVALID		0x10
69 #define DESC_LEN(len)		(len)
70 
71 /* Janz ICAN3 Firmware Messages */
72 #define MSG_CONNECTI		0x02
73 #define MSG_DISCONNECT		0x03
74 #define MSG_IDVERS		0x04
75 #define MSG_MSGLOST		0x05
76 #define MSG_NEWHOSTIF		0x08
77 #define MSG_INQUIRY		0x0a
78 #define MSG_SETAFILMASK		0x10
79 #define MSG_INITFDPMQUEUE	0x11
80 #define MSG_HWCONF		0x12
81 #define MSG_FMSGLOST		0x15
82 #define MSG_CEVTIND		0x37
83 #define MSG_CBTRREQ		0x41
84 #define MSG_COFFREQ		0x42
85 #define MSG_CONREQ		0x43
86 #define MSG_CCONFREQ		0x47
87 #define MSG_NMTS		0xb0
88 #define MSG_LMTS		0xb4
89 
90 /*
91  * Janz ICAN3 CAN Inquiry Message Types
92  *
93  * NOTE: there appears to be a firmware bug here. You must send
94  * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED
95  * NOTE: response. The controller never responds to a message with
96  * NOTE: the INQUIRY_EXTENDED subspec :(
97  */
98 #define INQUIRY_STATUS		0x00
99 #define INQUIRY_TERMINATION	0x01
100 #define INQUIRY_EXTENDED	0x04
101 
102 /* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */
103 #define SETAFILMASK_REJECT	0x00
104 #define SETAFILMASK_FASTIF	0x02
105 
106 /* Janz ICAN3 CAN Hardware Configuration Message Types */
107 #define HWCONF_TERMINATE_ON	0x01
108 #define HWCONF_TERMINATE_OFF	0x00
109 
110 /* Janz ICAN3 CAN Event Indication Message Types */
111 #define CEVTIND_EI		0x01
112 #define CEVTIND_DOI		0x02
113 #define CEVTIND_LOST		0x04
114 #define CEVTIND_FULL		0x08
115 #define CEVTIND_BEI		0x10
116 
117 #define CEVTIND_CHIP_SJA1000	0x02
118 
119 #define ICAN3_BUSERR_QUOTA_MAX	255
120 
121 /* Janz ICAN3 CAN Frame Conversion */
122 #define ICAN3_SNGL	0x02
123 #define ICAN3_ECHO	0x10
124 #define ICAN3_EFF_RTR	0x40
125 #define ICAN3_SFF_RTR	0x10
126 #define ICAN3_EFF	0x80
127 
128 #define ICAN3_CAN_TYPE_MASK	0x0f
129 #define ICAN3_CAN_TYPE_SFF	0x00
130 #define ICAN3_CAN_TYPE_EFF	0x01
131 
132 #define ICAN3_CAN_DLC_MASK	0x0f
133 
134 /* Janz ICAN3 NMTS subtypes */
135 #define NMTS_CREATE_NODE_REQ	0x0
136 #define NMTS_SLAVE_STATE_IND	0x8
137 #define NMTS_SLAVE_EVENT_IND	0x9
138 
139 /* Janz ICAN3 LMTS subtypes */
140 #define LMTS_BUSON_REQ		0x0
141 #define LMTS_BUSOFF_REQ		0x1
142 #define LMTS_CAN_CONF_REQ	0x2
143 
144 /* Janz ICAN3 NMTS Event indications */
145 #define NE_LOCAL_OCCURRED	0x3
146 #define NE_LOCAL_RESOLVED	0x2
147 #define NE_REMOTE_OCCURRED	0xc
148 #define NE_REMOTE_RESOLVED	0x8
149 
150 /*
151  * SJA1000 Status and Error Register Definitions
152  *
153  * Copied from drivers/net/can/sja1000/sja1000.h
154  */
155 
156 /* status register content */
157 #define SR_BS		0x80
158 #define SR_ES		0x40
159 #define SR_TS		0x20
160 #define SR_RS		0x10
161 #define SR_TCS		0x08
162 #define SR_TBS		0x04
163 #define SR_DOS		0x02
164 #define SR_RBS		0x01
165 
166 #define SR_CRIT (SR_BS|SR_ES)
167 
168 /* ECC register */
169 #define ECC_SEG		0x1F
170 #define ECC_DIR		0x20
171 #define ECC_ERR		6
172 #define ECC_BIT		0x00
173 #define ECC_FORM	0x40
174 #define ECC_STUFF	0x80
175 #define ECC_MASK	0xc0
176 
177 /* Number of buffers for use in the "new-style" host interface */
178 #define ICAN3_NEW_BUFFERS	16
179 
180 /* Number of buffers for use in the "fast" host interface */
181 #define ICAN3_TX_BUFFERS	512
182 #define ICAN3_RX_BUFFERS	1024
183 
184 /* SJA1000 Clock Input */
185 #define ICAN3_CAN_CLOCK		8000000
186 
187 /* Janz ICAN3 firmware types */
188 enum ican3_fwtype {
189 	ICAN3_FWTYPE_ICANOS,
190 	ICAN3_FWTYPE_CAL_CANOPEN,
191 };
192 
193 /* Driver Name */
194 #define DRV_NAME "janz-ican3"
195 
196 /* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */
197 struct ican3_dpm_control {
198 	/* window address register */
199 	u8 window_address;
200 	u8 unused1;
201 
202 	/*
203 	 * Read access: clear interrupt from microcontroller
204 	 * Write access: send interrupt to microcontroller
205 	 */
206 	u8 interrupt;
207 	u8 unused2;
208 
209 	/* write-only: reset all hardware on the module */
210 	u8 hwreset;
211 	u8 unused3;
212 
213 	/* write-only: generate an interrupt to the TPU */
214 	u8 tpuinterrupt;
215 };
216 
217 struct ican3_dev {
218 
219 	/* must be the first member */
220 	struct can_priv can;
221 
222 	/* CAN network device */
223 	struct net_device *ndev;
224 	struct napi_struct napi;
225 
226 	/* module number */
227 	unsigned int num;
228 
229 	/* base address of registers and IRQ */
230 	struct janz_cmodio_onboard_regs __iomem *ctrl;
231 	struct ican3_dpm_control __iomem *dpmctrl;
232 	void __iomem *dpm;
233 	int irq;
234 
235 	/* CAN bus termination status */
236 	struct completion termination_comp;
237 	bool termination_enabled;
238 
239 	/* CAN bus error status registers */
240 	struct completion buserror_comp;
241 	struct can_berr_counter bec;
242 
243 	/* firmware type */
244 	enum ican3_fwtype fwtype;
245 	char fwinfo[32];
246 
247 	/* old and new style host interface */
248 	unsigned int iftype;
249 
250 	/* queue for echo packets */
251 	struct sk_buff_head echoq;
252 
253 	/*
254 	 * Any function which changes the current DPM page must hold this
255 	 * lock while it is performing data accesses. This ensures that the
256 	 * function will not be preempted and end up reading data from a
257 	 * different DPM page than it expects.
258 	 */
259 	spinlock_t lock;
260 
261 	/* new host interface */
262 	unsigned int rx_int;
263 	unsigned int rx_num;
264 	unsigned int tx_num;
265 
266 	/* fast host interface */
267 	unsigned int fastrx_start;
268 	unsigned int fastrx_num;
269 	unsigned int fasttx_start;
270 	unsigned int fasttx_num;
271 
272 	/* first free DPM page */
273 	unsigned int free_page;
274 };
275 
276 struct ican3_msg {
277 	u8 control;
278 	u8 spec;
279 	__le16 len;
280 	u8 data[252];
281 };
282 
283 struct ican3_new_desc {
284 	u8 control;
285 	u8 pointer;
286 };
287 
288 struct ican3_fast_desc {
289 	u8 control;
290 	u8 command;
291 	u8 data[14];
292 };
293 
294 /* write to the window basic address register */
295 static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page)
296 {
297 	BUG_ON(page >= DPM_NUM_PAGES);
298 	iowrite8(page, &mod->dpmctrl->window_address);
299 }
300 
301 /*
302  * ICAN3 "old-style" host interface
303  */
304 
305 /*
306  * Receive a message from the ICAN3 "old-style" firmware interface
307  *
308  * LOCKING: must hold mod->lock
309  *
310  * returns 0 on success, -ENOMEM when no message exists
311  */
312 static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
313 {
314 	unsigned int mbox, mbox_page;
315 	u8 locl, peer, xord;
316 
317 	/* get the MSYNC registers */
318 	ican3_set_page(mod, QUEUE_OLD_CONTROL);
319 	peer = ioread8(mod->dpm + MSYNC_PEER);
320 	locl = ioread8(mod->dpm + MSYNC_LOCL);
321 	xord = locl ^ peer;
322 
323 	if ((xord & MSYNC_RB_MASK) == 0x00) {
324 		netdev_dbg(mod->ndev, "no mbox for reading\n");
325 		return -ENOMEM;
326 	}
327 
328 	/* find the first free mbox to read */
329 	if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK)
330 		mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1;
331 	else
332 		mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1;
333 
334 	/* copy the message */
335 	mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1;
336 	ican3_set_page(mod, mbox_page);
337 	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
338 
339 	/*
340 	 * notify the firmware that the read buffer is available
341 	 * for it to fill again
342 	 */
343 	locl ^= mbox;
344 
345 	ican3_set_page(mod, QUEUE_OLD_CONTROL);
346 	iowrite8(locl, mod->dpm + MSYNC_LOCL);
347 	return 0;
348 }
349 
350 /*
351  * Send a message through the "old-style" firmware interface
352  *
353  * LOCKING: must hold mod->lock
354  *
355  * returns 0 on success, -ENOMEM when no free space exists
356  */
357 static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
358 {
359 	unsigned int mbox, mbox_page;
360 	u8 locl, peer, xord;
361 
362 	/* get the MSYNC registers */
363 	ican3_set_page(mod, QUEUE_OLD_CONTROL);
364 	peer = ioread8(mod->dpm + MSYNC_PEER);
365 	locl = ioread8(mod->dpm + MSYNC_LOCL);
366 	xord = locl ^ peer;
367 
368 	if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) {
369 		netdev_err(mod->ndev, "no mbox for writing\n");
370 		return -ENOMEM;
371 	}
372 
373 	/* calculate a free mbox to use */
374 	mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0;
375 
376 	/* copy the message to the DPM */
377 	mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1;
378 	ican3_set_page(mod, mbox_page);
379 	memcpy_toio(mod->dpm, msg, sizeof(*msg));
380 
381 	locl ^= mbox;
382 	if (mbox == MSYNC_WB1)
383 		locl |= MSYNC_WBLW;
384 
385 	ican3_set_page(mod, QUEUE_OLD_CONTROL);
386 	iowrite8(locl, mod->dpm + MSYNC_LOCL);
387 	return 0;
388 }
389 
390 /*
391  * ICAN3 "new-style" Host Interface Setup
392  */
393 
394 static void ican3_init_new_host_interface(struct ican3_dev *mod)
395 {
396 	struct ican3_new_desc desc;
397 	unsigned long flags;
398 	void __iomem *dst;
399 	int i;
400 
401 	spin_lock_irqsave(&mod->lock, flags);
402 
403 	/* setup the internal datastructures for RX */
404 	mod->rx_num = 0;
405 	mod->rx_int = 0;
406 
407 	/* tohost queue descriptors are in page 5 */
408 	ican3_set_page(mod, QUEUE_TOHOST);
409 	dst = mod->dpm;
410 
411 	/* initialize the tohost (rx) queue descriptors: pages 9-24 */
412 	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
413 		desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */
414 		desc.pointer = mod->free_page;
415 
416 		/* set wrap flag on last buffer */
417 		if (i == ICAN3_NEW_BUFFERS - 1)
418 			desc.control |= DESC_WRAP;
419 
420 		memcpy_toio(dst, &desc, sizeof(desc));
421 		dst += sizeof(desc);
422 		mod->free_page++;
423 	}
424 
425 	/* fromhost (tx) mid queue descriptors are in page 6 */
426 	ican3_set_page(mod, QUEUE_FROMHOST_MID);
427 	dst = mod->dpm;
428 
429 	/* setup the internal datastructures for TX */
430 	mod->tx_num = 0;
431 
432 	/* initialize the fromhost mid queue descriptors: pages 25-40 */
433 	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
434 		desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */
435 		desc.pointer = mod->free_page;
436 
437 		/* set wrap flag on last buffer */
438 		if (i == ICAN3_NEW_BUFFERS - 1)
439 			desc.control |= DESC_WRAP;
440 
441 		memcpy_toio(dst, &desc, sizeof(desc));
442 		dst += sizeof(desc);
443 		mod->free_page++;
444 	}
445 
446 	/* fromhost hi queue descriptors are in page 7 */
447 	ican3_set_page(mod, QUEUE_FROMHOST_HIGH);
448 	dst = mod->dpm;
449 
450 	/* initialize only a single buffer in the fromhost hi queue (unused) */
451 	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
452 	desc.pointer = mod->free_page;
453 	memcpy_toio(dst, &desc, sizeof(desc));
454 	mod->free_page++;
455 
456 	/* fromhost low queue descriptors are in page 8 */
457 	ican3_set_page(mod, QUEUE_FROMHOST_LOW);
458 	dst = mod->dpm;
459 
460 	/* initialize only a single buffer in the fromhost low queue (unused) */
461 	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
462 	desc.pointer = mod->free_page;
463 	memcpy_toio(dst, &desc, sizeof(desc));
464 	mod->free_page++;
465 
466 	spin_unlock_irqrestore(&mod->lock, flags);
467 }
468 
469 /*
470  * ICAN3 Fast Host Interface Setup
471  */
472 
473 static void ican3_init_fast_host_interface(struct ican3_dev *mod)
474 {
475 	struct ican3_fast_desc desc;
476 	unsigned long flags;
477 	unsigned int addr;
478 	void __iomem *dst;
479 	int i;
480 
481 	spin_lock_irqsave(&mod->lock, flags);
482 
483 	/* save the start recv page */
484 	mod->fastrx_start = mod->free_page;
485 	mod->fastrx_num = 0;
486 
487 	/* build a single fast tohost queue descriptor */
488 	memset(&desc, 0, sizeof(desc));
489 	desc.control = 0x00;
490 	desc.command = 1;
491 
492 	/* build the tohost queue descriptor ring in memory */
493 	addr = 0;
494 	for (i = 0; i < ICAN3_RX_BUFFERS; i++) {
495 
496 		/* set the wrap bit on the last buffer */
497 		if (i == ICAN3_RX_BUFFERS - 1)
498 			desc.control |= DESC_WRAP;
499 
500 		/* switch to the correct page */
501 		ican3_set_page(mod, mod->free_page);
502 
503 		/* copy the descriptor to the DPM */
504 		dst = mod->dpm + addr;
505 		memcpy_toio(dst, &desc, sizeof(desc));
506 		addr += sizeof(desc);
507 
508 		/* move to the next page if necessary */
509 		if (addr >= DPM_PAGE_SIZE) {
510 			addr = 0;
511 			mod->free_page++;
512 		}
513 	}
514 
515 	/* make sure we page-align the next queue */
516 	if (addr != 0)
517 		mod->free_page++;
518 
519 	/* save the start xmit page */
520 	mod->fasttx_start = mod->free_page;
521 	mod->fasttx_num = 0;
522 
523 	/* build a single fast fromhost queue descriptor */
524 	memset(&desc, 0, sizeof(desc));
525 	desc.control = DESC_VALID;
526 	desc.command = 1;
527 
528 	/* build the fromhost queue descriptor ring in memory */
529 	addr = 0;
530 	for (i = 0; i < ICAN3_TX_BUFFERS; i++) {
531 
532 		/* set the wrap bit on the last buffer */
533 		if (i == ICAN3_TX_BUFFERS - 1)
534 			desc.control |= DESC_WRAP;
535 
536 		/* switch to the correct page */
537 		ican3_set_page(mod, mod->free_page);
538 
539 		/* copy the descriptor to the DPM */
540 		dst = mod->dpm + addr;
541 		memcpy_toio(dst, &desc, sizeof(desc));
542 		addr += sizeof(desc);
543 
544 		/* move to the next page if necessary */
545 		if (addr >= DPM_PAGE_SIZE) {
546 			addr = 0;
547 			mod->free_page++;
548 		}
549 	}
550 
551 	spin_unlock_irqrestore(&mod->lock, flags);
552 }
553 
554 /*
555  * ICAN3 "new-style" Host Interface Message Helpers
556  */
557 
558 /*
559  * LOCKING: must hold mod->lock
560  */
561 static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
562 {
563 	struct ican3_new_desc desc;
564 	void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc));
565 
566 	/* switch to the fromhost mid queue, and read the buffer descriptor */
567 	ican3_set_page(mod, QUEUE_FROMHOST_MID);
568 	memcpy_fromio(&desc, desc_addr, sizeof(desc));
569 
570 	if (!(desc.control & DESC_VALID)) {
571 		netdev_dbg(mod->ndev, "%s: no free buffers\n", __func__);
572 		return -ENOMEM;
573 	}
574 
575 	/* switch to the data page, copy the data */
576 	ican3_set_page(mod, desc.pointer);
577 	memcpy_toio(mod->dpm, msg, sizeof(*msg));
578 
579 	/* switch back to the descriptor, set the valid bit, write it back */
580 	ican3_set_page(mod, QUEUE_FROMHOST_MID);
581 	desc.control ^= DESC_VALID;
582 	memcpy_toio(desc_addr, &desc, sizeof(desc));
583 
584 	/* update the tx number */
585 	mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1);
586 	return 0;
587 }
588 
589 /*
590  * LOCKING: must hold mod->lock
591  */
592 static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
593 {
594 	struct ican3_new_desc desc;
595 	void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc));
596 
597 	/* switch to the tohost queue, and read the buffer descriptor */
598 	ican3_set_page(mod, QUEUE_TOHOST);
599 	memcpy_fromio(&desc, desc_addr, sizeof(desc));
600 
601 	if (!(desc.control & DESC_VALID)) {
602 		netdev_dbg(mod->ndev, "%s: no buffers to recv\n", __func__);
603 		return -ENOMEM;
604 	}
605 
606 	/* switch to the data page, copy the data */
607 	ican3_set_page(mod, desc.pointer);
608 	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
609 
610 	/* switch back to the descriptor, toggle the valid bit, write it back */
611 	ican3_set_page(mod, QUEUE_TOHOST);
612 	desc.control ^= DESC_VALID;
613 	memcpy_toio(desc_addr, &desc, sizeof(desc));
614 
615 	/* update the rx number */
616 	mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1);
617 	return 0;
618 }
619 
620 /*
621  * Message Send / Recv Helpers
622  */
623 
624 static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
625 {
626 	unsigned long flags;
627 	int ret;
628 
629 	spin_lock_irqsave(&mod->lock, flags);
630 
631 	if (mod->iftype == 0)
632 		ret = ican3_old_send_msg(mod, msg);
633 	else
634 		ret = ican3_new_send_msg(mod, msg);
635 
636 	spin_unlock_irqrestore(&mod->lock, flags);
637 	return ret;
638 }
639 
640 static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
641 {
642 	unsigned long flags;
643 	int ret;
644 
645 	spin_lock_irqsave(&mod->lock, flags);
646 
647 	if (mod->iftype == 0)
648 		ret = ican3_old_recv_msg(mod, msg);
649 	else
650 		ret = ican3_new_recv_msg(mod, msg);
651 
652 	spin_unlock_irqrestore(&mod->lock, flags);
653 	return ret;
654 }
655 
656 /*
657  * Quick Pre-constructed Messages
658  */
659 
660 static int ican3_msg_connect(struct ican3_dev *mod)
661 {
662 	struct ican3_msg msg;
663 
664 	memset(&msg, 0, sizeof(msg));
665 	msg.spec = MSG_CONNECTI;
666 	msg.len = cpu_to_le16(0);
667 
668 	return ican3_send_msg(mod, &msg);
669 }
670 
671 static int ican3_msg_disconnect(struct ican3_dev *mod)
672 {
673 	struct ican3_msg msg;
674 
675 	memset(&msg, 0, sizeof(msg));
676 	msg.spec = MSG_DISCONNECT;
677 	msg.len = cpu_to_le16(0);
678 
679 	return ican3_send_msg(mod, &msg);
680 }
681 
682 static int ican3_msg_newhostif(struct ican3_dev *mod)
683 {
684 	struct ican3_msg msg;
685 	int ret;
686 
687 	memset(&msg, 0, sizeof(msg));
688 	msg.spec = MSG_NEWHOSTIF;
689 	msg.len = cpu_to_le16(0);
690 
691 	/* If we're not using the old interface, switching seems bogus */
692 	WARN_ON(mod->iftype != 0);
693 
694 	ret = ican3_send_msg(mod, &msg);
695 	if (ret)
696 		return ret;
697 
698 	/* mark the module as using the new host interface */
699 	mod->iftype = 1;
700 	return 0;
701 }
702 
703 static int ican3_msg_fasthostif(struct ican3_dev *mod)
704 {
705 	struct ican3_msg msg;
706 	unsigned int addr;
707 
708 	memset(&msg, 0, sizeof(msg));
709 	msg.spec = MSG_INITFDPMQUEUE;
710 	msg.len = cpu_to_le16(8);
711 
712 	/* write the tohost queue start address */
713 	addr = DPM_PAGE_ADDR(mod->fastrx_start);
714 	msg.data[0] = addr & 0xff;
715 	msg.data[1] = (addr >> 8) & 0xff;
716 	msg.data[2] = (addr >> 16) & 0xff;
717 	msg.data[3] = (addr >> 24) & 0xff;
718 
719 	/* write the fromhost queue start address */
720 	addr = DPM_PAGE_ADDR(mod->fasttx_start);
721 	msg.data[4] = addr & 0xff;
722 	msg.data[5] = (addr >> 8) & 0xff;
723 	msg.data[6] = (addr >> 16) & 0xff;
724 	msg.data[7] = (addr >> 24) & 0xff;
725 
726 	/* If we're not using the new interface yet, we cannot do this */
727 	WARN_ON(mod->iftype != 1);
728 
729 	return ican3_send_msg(mod, &msg);
730 }
731 
732 /*
733  * Setup the CAN filter to either accept or reject all
734  * messages from the CAN bus.
735  */
736 static int ican3_set_id_filter(struct ican3_dev *mod, bool accept)
737 {
738 	struct ican3_msg msg;
739 	int ret;
740 
741 	/* Standard Frame Format */
742 	memset(&msg, 0, sizeof(msg));
743 	msg.spec = MSG_SETAFILMASK;
744 	msg.len = cpu_to_le16(5);
745 	msg.data[0] = 0x00; /* IDLo LSB */
746 	msg.data[1] = 0x00; /* IDLo MSB */
747 	msg.data[2] = 0xff; /* IDHi LSB */
748 	msg.data[3] = 0x07; /* IDHi MSB */
749 
750 	/* accept all frames for fast host if, or reject all frames */
751 	msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
752 
753 	ret = ican3_send_msg(mod, &msg);
754 	if (ret)
755 		return ret;
756 
757 	/* Extended Frame Format */
758 	memset(&msg, 0, sizeof(msg));
759 	msg.spec = MSG_SETAFILMASK;
760 	msg.len = cpu_to_le16(13);
761 	msg.data[0] = 0;    /* MUX = 0 */
762 	msg.data[1] = 0x00; /* IDLo LSB */
763 	msg.data[2] = 0x00;
764 	msg.data[3] = 0x00;
765 	msg.data[4] = 0x20; /* IDLo MSB */
766 	msg.data[5] = 0xff; /* IDHi LSB */
767 	msg.data[6] = 0xff;
768 	msg.data[7] = 0xff;
769 	msg.data[8] = 0x3f; /* IDHi MSB */
770 
771 	/* accept all frames for fast host if, or reject all frames */
772 	msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
773 
774 	return ican3_send_msg(mod, &msg);
775 }
776 
777 /*
778  * Bring the CAN bus online or offline
779  */
780 static int ican3_set_bus_state(struct ican3_dev *mod, bool on)
781 {
782 	struct can_bittiming *bt = &mod->can.bittiming;
783 	struct ican3_msg msg;
784 	u8 btr0, btr1;
785 	int res;
786 
787 	/* This algorithm was stolen from drivers/net/can/sja1000/sja1000.c      */
788 	/* The bittiming register command for the ICAN3 just sets the bit timing */
789 	/* registers on the SJA1000 chip directly                                */
790 	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
791 	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
792 		(((bt->phase_seg2 - 1) & 0x7) << 4);
793 	if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
794 		btr1 |= 0x80;
795 
796 	if (mod->fwtype == ICAN3_FWTYPE_ICANOS) {
797 		if (on) {
798 			/* set bittiming */
799 			memset(&msg, 0, sizeof(msg));
800 			msg.spec = MSG_CBTRREQ;
801 			msg.len = cpu_to_le16(4);
802 			msg.data[0] = 0x00;
803 			msg.data[1] = 0x00;
804 			msg.data[2] = btr0;
805 			msg.data[3] = btr1;
806 
807 			res = ican3_send_msg(mod, &msg);
808 			if (res)
809 				return res;
810 		}
811 
812 		/* can-on/off request */
813 		memset(&msg, 0, sizeof(msg));
814 		msg.spec = on ? MSG_CONREQ : MSG_COFFREQ;
815 		msg.len = cpu_to_le16(0);
816 
817 		return ican3_send_msg(mod, &msg);
818 
819 	} else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) {
820 		/* bittiming + can-on/off request */
821 		memset(&msg, 0, sizeof(msg));
822 		msg.spec = MSG_LMTS;
823 		if (on) {
824 			msg.len = cpu_to_le16(4);
825 			msg.data[0] = LMTS_BUSON_REQ;
826 			msg.data[1] = 0;
827 			msg.data[2] = btr0;
828 			msg.data[3] = btr1;
829 		} else {
830 			msg.len = cpu_to_le16(2);
831 			msg.data[0] = LMTS_BUSOFF_REQ;
832 			msg.data[1] = 0;
833 		}
834 		res = ican3_send_msg(mod, &msg);
835 		if (res)
836 			return res;
837 
838 		if (on) {
839 			/* create NMT Slave Node for error processing
840 			 *   class 2 (with error capability, see CiA/DS203-1)
841 			 *   id    1
842 			 *   name  locnod1 (must be exactly 7 bytes)
843 			 */
844 			memset(&msg, 0, sizeof(msg));
845 			msg.spec = MSG_NMTS;
846 			msg.len = cpu_to_le16(11);
847 			msg.data[0] = NMTS_CREATE_NODE_REQ;
848 			msg.data[1] = 0;
849 			msg.data[2] = 2;                 /* node class */
850 			msg.data[3] = 1;                 /* node id */
851 			strcpy(msg.data + 4, "locnod1"); /* node name  */
852 			return ican3_send_msg(mod, &msg);
853 		}
854 		return 0;
855 	}
856 	return -ENOTSUPP;
857 }
858 
859 static int ican3_set_termination(struct ican3_dev *mod, bool on)
860 {
861 	struct ican3_msg msg;
862 
863 	memset(&msg, 0, sizeof(msg));
864 	msg.spec = MSG_HWCONF;
865 	msg.len = cpu_to_le16(2);
866 	msg.data[0] = 0x00;
867 	msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF;
868 
869 	return ican3_send_msg(mod, &msg);
870 }
871 
872 static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec)
873 {
874 	struct ican3_msg msg;
875 
876 	memset(&msg, 0, sizeof(msg));
877 	msg.spec = MSG_INQUIRY;
878 	msg.len = cpu_to_le16(2);
879 	msg.data[0] = subspec;
880 	msg.data[1] = 0x00;
881 
882 	return ican3_send_msg(mod, &msg);
883 }
884 
885 static int ican3_set_buserror(struct ican3_dev *mod, u8 quota)
886 {
887 	struct ican3_msg msg;
888 
889 	if (mod->fwtype == ICAN3_FWTYPE_ICANOS) {
890 		memset(&msg, 0, sizeof(msg));
891 		msg.spec = MSG_CCONFREQ;
892 		msg.len = cpu_to_le16(2);
893 		msg.data[0] = 0x00;
894 		msg.data[1] = quota;
895 	} else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) {
896 		memset(&msg, 0, sizeof(msg));
897 		msg.spec = MSG_LMTS;
898 		msg.len = cpu_to_le16(4);
899 		msg.data[0] = LMTS_CAN_CONF_REQ;
900 		msg.data[1] = 0x00;
901 		msg.data[2] = 0x00;
902 		msg.data[3] = quota;
903 	} else {
904 		return -ENOTSUPP;
905 	}
906 	return ican3_send_msg(mod, &msg);
907 }
908 
909 /*
910  * ICAN3 to Linux CAN Frame Conversion
911  */
912 
913 static void ican3_to_can_frame(struct ican3_dev *mod,
914 			       struct ican3_fast_desc *desc,
915 			       struct can_frame *cf)
916 {
917 	if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) {
918 		if (desc->data[1] & ICAN3_SFF_RTR)
919 			cf->can_id |= CAN_RTR_FLAG;
920 
921 		cf->can_id |= desc->data[0] << 3;
922 		cf->can_id |= (desc->data[1] & 0xe0) >> 5;
923 		cf->can_dlc = get_can_dlc(desc->data[1] & ICAN3_CAN_DLC_MASK);
924 		memcpy(cf->data, &desc->data[2], cf->can_dlc);
925 	} else {
926 		cf->can_dlc = get_can_dlc(desc->data[0] & ICAN3_CAN_DLC_MASK);
927 		if (desc->data[0] & ICAN3_EFF_RTR)
928 			cf->can_id |= CAN_RTR_FLAG;
929 
930 		if (desc->data[0] & ICAN3_EFF) {
931 			cf->can_id |= CAN_EFF_FLAG;
932 			cf->can_id |= desc->data[2] << 21; /* 28-21 */
933 			cf->can_id |= desc->data[3] << 13; /* 20-13 */
934 			cf->can_id |= desc->data[4] << 5;  /* 12-5  */
935 			cf->can_id |= (desc->data[5] & 0xf8) >> 3;
936 		} else {
937 			cf->can_id |= desc->data[2] << 3;  /* 10-3  */
938 			cf->can_id |= desc->data[3] >> 5;  /* 2-0   */
939 		}
940 
941 		memcpy(cf->data, &desc->data[6], cf->can_dlc);
942 	}
943 }
944 
945 static void can_frame_to_ican3(struct ican3_dev *mod,
946 			       struct can_frame *cf,
947 			       struct ican3_fast_desc *desc)
948 {
949 	/* clear out any stale data in the descriptor */
950 	memset(desc->data, 0, sizeof(desc->data));
951 
952 	/* we always use the extended format, with the ECHO flag set */
953 	desc->command = ICAN3_CAN_TYPE_EFF;
954 	desc->data[0] |= cf->can_dlc;
955 	desc->data[1] |= ICAN3_ECHO;
956 
957 	/* support single transmission (no retries) mode */
958 	if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
959 		desc->data[1] |= ICAN3_SNGL;
960 
961 	if (cf->can_id & CAN_RTR_FLAG)
962 		desc->data[0] |= ICAN3_EFF_RTR;
963 
964 	/* pack the id into the correct places */
965 	if (cf->can_id & CAN_EFF_FLAG) {
966 		desc->data[0] |= ICAN3_EFF;
967 		desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */
968 		desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */
969 		desc->data[4] = (cf->can_id & 0x00001fe0) >> 5;  /* 12-5  */
970 		desc->data[5] = (cf->can_id & 0x0000001f) << 3;  /* 4-0   */
971 	} else {
972 		desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */
973 		desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0  */
974 	}
975 
976 	/* copy the data bits into the descriptor */
977 	memcpy(&desc->data[6], cf->data, cf->can_dlc);
978 }
979 
980 /*
981  * Interrupt Handling
982  */
983 
984 /*
985  * Handle an ID + Version message response from the firmware. We never generate
986  * this message in production code, but it is very useful when debugging to be
987  * able to display this message.
988  */
989 static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg)
990 {
991 	netdev_dbg(mod->ndev, "IDVERS response: %s\n", msg->data);
992 }
993 
994 static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg)
995 {
996 	struct net_device *dev = mod->ndev;
997 	struct net_device_stats *stats = &dev->stats;
998 	struct can_frame *cf;
999 	struct sk_buff *skb;
1000 
1001 	/*
1002 	 * Report that communication messages with the microcontroller firmware
1003 	 * are being lost. These are never CAN frames, so we do not generate an
1004 	 * error frame for userspace
1005 	 */
1006 	if (msg->spec == MSG_MSGLOST) {
1007 		netdev_err(mod->ndev, "lost %d control messages\n", msg->data[0]);
1008 		return;
1009 	}
1010 
1011 	/*
1012 	 * Oops, this indicates that we have lost messages in the fast queue,
1013 	 * which are exclusively CAN messages. Our driver isn't reading CAN
1014 	 * frames fast enough.
1015 	 *
1016 	 * We'll pretend that the SJA1000 told us that it ran out of buffer
1017 	 * space, because there is not a better message for this.
1018 	 */
1019 	skb = alloc_can_err_skb(dev, &cf);
1020 	if (skb) {
1021 		cf->can_id |= CAN_ERR_CRTL;
1022 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
1023 		stats->rx_over_errors++;
1024 		stats->rx_errors++;
1025 		netif_rx(skb);
1026 	}
1027 }
1028 
1029 /*
1030  * Handle CAN Event Indication Messages from the firmware
1031  *
1032  * The ICAN3 firmware provides the values of some SJA1000 registers when it
1033  * generates this message. The code below is largely copied from the
1034  * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary
1035  */
1036 static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg)
1037 {
1038 	struct net_device *dev = mod->ndev;
1039 	struct net_device_stats *stats = &dev->stats;
1040 	enum can_state state = mod->can.state;
1041 	u8 isrc, ecc, status, rxerr, txerr;
1042 	struct can_frame *cf;
1043 	struct sk_buff *skb;
1044 
1045 	/* we can only handle the SJA1000 part */
1046 	if (msg->data[1] != CEVTIND_CHIP_SJA1000) {
1047 		netdev_err(mod->ndev, "unable to handle errors on non-SJA1000\n");
1048 		return -ENODEV;
1049 	}
1050 
1051 	/* check the message length for sanity */
1052 	if (le16_to_cpu(msg->len) < 6) {
1053 		netdev_err(mod->ndev, "error message too short\n");
1054 		return -EINVAL;
1055 	}
1056 
1057 	isrc = msg->data[0];
1058 	ecc = msg->data[2];
1059 	status = msg->data[3];
1060 	rxerr = msg->data[4];
1061 	txerr = msg->data[5];
1062 
1063 	/*
1064 	 * This hardware lacks any support other than bus error messages to
1065 	 * determine if packet transmission has failed.
1066 	 *
1067 	 * When TX errors happen, one echo skb needs to be dropped from the
1068 	 * front of the queue.
1069 	 *
1070 	 * A small bit of code is duplicated here and below, to avoid error
1071 	 * skb allocation when it will just be freed immediately.
1072 	 */
1073 	if (isrc == CEVTIND_BEI) {
1074 		int ret;
1075 		netdev_dbg(mod->ndev, "bus error interrupt\n");
1076 
1077 		/* TX error */
1078 		if (!(ecc & ECC_DIR)) {
1079 			kfree_skb(skb_dequeue(&mod->echoq));
1080 			stats->tx_errors++;
1081 		} else {
1082 			stats->rx_errors++;
1083 		}
1084 
1085 		/*
1086 		 * The controller automatically disables bus-error interrupts
1087 		 * and therefore we must re-enable them.
1088 		 */
1089 		ret = ican3_set_buserror(mod, 1);
1090 		if (ret) {
1091 			netdev_err(mod->ndev, "unable to re-enable bus-error\n");
1092 			return ret;
1093 		}
1094 
1095 		/* bus error reporting is off, return immediately */
1096 		if (!(mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1097 			return 0;
1098 	}
1099 
1100 	skb = alloc_can_err_skb(dev, &cf);
1101 	if (skb == NULL)
1102 		return -ENOMEM;
1103 
1104 	/* data overrun interrupt */
1105 	if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) {
1106 		netdev_dbg(mod->ndev, "data overrun interrupt\n");
1107 		cf->can_id |= CAN_ERR_CRTL;
1108 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
1109 		stats->rx_over_errors++;
1110 		stats->rx_errors++;
1111 	}
1112 
1113 	/* error warning + passive interrupt */
1114 	if (isrc == CEVTIND_EI) {
1115 		netdev_dbg(mod->ndev, "error warning + passive interrupt\n");
1116 		if (status & SR_BS) {
1117 			state = CAN_STATE_BUS_OFF;
1118 			cf->can_id |= CAN_ERR_BUSOFF;
1119 			mod->can.can_stats.bus_off++;
1120 			can_bus_off(dev);
1121 		} else if (status & SR_ES) {
1122 			if (rxerr >= 128 || txerr >= 128)
1123 				state = CAN_STATE_ERROR_PASSIVE;
1124 			else
1125 				state = CAN_STATE_ERROR_WARNING;
1126 		} else {
1127 			state = CAN_STATE_ERROR_ACTIVE;
1128 		}
1129 	}
1130 
1131 	/* bus error interrupt */
1132 	if (isrc == CEVTIND_BEI) {
1133 		mod->can.can_stats.bus_error++;
1134 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
1135 
1136 		switch (ecc & ECC_MASK) {
1137 		case ECC_BIT:
1138 			cf->data[2] |= CAN_ERR_PROT_BIT;
1139 			break;
1140 		case ECC_FORM:
1141 			cf->data[2] |= CAN_ERR_PROT_FORM;
1142 			break;
1143 		case ECC_STUFF:
1144 			cf->data[2] |= CAN_ERR_PROT_STUFF;
1145 			break;
1146 		default:
1147 			cf->data[3] = ecc & ECC_SEG;
1148 			break;
1149 		}
1150 
1151 		if (!(ecc & ECC_DIR))
1152 			cf->data[2] |= CAN_ERR_PROT_TX;
1153 
1154 		cf->data[6] = txerr;
1155 		cf->data[7] = rxerr;
1156 	}
1157 
1158 	if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING ||
1159 					state == CAN_STATE_ERROR_PASSIVE)) {
1160 		cf->can_id |= CAN_ERR_CRTL;
1161 		if (state == CAN_STATE_ERROR_WARNING) {
1162 			mod->can.can_stats.error_warning++;
1163 			cf->data[1] = (txerr > rxerr) ?
1164 				CAN_ERR_CRTL_TX_WARNING :
1165 				CAN_ERR_CRTL_RX_WARNING;
1166 		} else {
1167 			mod->can.can_stats.error_passive++;
1168 			cf->data[1] = (txerr > rxerr) ?
1169 				CAN_ERR_CRTL_TX_PASSIVE :
1170 				CAN_ERR_CRTL_RX_PASSIVE;
1171 		}
1172 
1173 		cf->data[6] = txerr;
1174 		cf->data[7] = rxerr;
1175 	}
1176 
1177 	mod->can.state = state;
1178 	netif_rx(skb);
1179 	return 0;
1180 }
1181 
1182 static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg)
1183 {
1184 	switch (msg->data[0]) {
1185 	case INQUIRY_STATUS:
1186 	case INQUIRY_EXTENDED:
1187 		mod->bec.rxerr = msg->data[5];
1188 		mod->bec.txerr = msg->data[6];
1189 		complete(&mod->buserror_comp);
1190 		break;
1191 	case INQUIRY_TERMINATION:
1192 		mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON;
1193 		complete(&mod->termination_comp);
1194 		break;
1195 	default:
1196 		netdev_err(mod->ndev, "received an unknown inquiry response\n");
1197 		break;
1198 	}
1199 }
1200 
1201 /* Handle NMTS Slave Event Indication Messages from the firmware */
1202 static void ican3_handle_nmtsind(struct ican3_dev *mod, struct ican3_msg *msg)
1203 {
1204 	u16 subspec;
1205 
1206 	subspec = msg->data[0] + msg->data[1] * 0x100;
1207 	if (subspec == NMTS_SLAVE_EVENT_IND) {
1208 		switch (msg->data[2]) {
1209 		case NE_LOCAL_OCCURRED:
1210 		case NE_LOCAL_RESOLVED:
1211 			/* now follows the same message as Raw ICANOS CEVTIND
1212 			 * shift the data at the same place and call this method
1213 			 */
1214 			le16_add_cpu(&msg->len, -3);
1215 			memmove(msg->data, msg->data + 3, le16_to_cpu(msg->len));
1216 			ican3_handle_cevtind(mod, msg);
1217 			break;
1218 		case NE_REMOTE_OCCURRED:
1219 		case NE_REMOTE_RESOLVED:
1220 			/* should not occurre, ignore */
1221 			break;
1222 		default:
1223 			netdev_warn(mod->ndev, "unknown NMTS event indication %x\n",
1224 				    msg->data[2]);
1225 			break;
1226 		}
1227 	} else if (subspec == NMTS_SLAVE_STATE_IND) {
1228 		/* ignore state indications */
1229 	} else {
1230 		netdev_warn(mod->ndev, "unhandled NMTS indication %x\n",
1231 			    subspec);
1232 		return;
1233 	}
1234 }
1235 
1236 static void ican3_handle_unknown_message(struct ican3_dev *mod,
1237 					struct ican3_msg *msg)
1238 {
1239 	netdev_warn(mod->ndev, "received unknown message: spec 0x%.2x length %d\n",
1240 			   msg->spec, le16_to_cpu(msg->len));
1241 }
1242 
1243 /*
1244  * Handle a control message from the firmware
1245  */
1246 static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg)
1247 {
1248 	netdev_dbg(mod->ndev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__,
1249 			   mod->num, msg->spec, le16_to_cpu(msg->len));
1250 
1251 	switch (msg->spec) {
1252 	case MSG_IDVERS:
1253 		ican3_handle_idvers(mod, msg);
1254 		break;
1255 	case MSG_MSGLOST:
1256 	case MSG_FMSGLOST:
1257 		ican3_handle_msglost(mod, msg);
1258 		break;
1259 	case MSG_CEVTIND:
1260 		ican3_handle_cevtind(mod, msg);
1261 		break;
1262 	case MSG_INQUIRY:
1263 		ican3_handle_inquiry(mod, msg);
1264 		break;
1265 	case MSG_NMTS:
1266 		ican3_handle_nmtsind(mod, msg);
1267 		break;
1268 	default:
1269 		ican3_handle_unknown_message(mod, msg);
1270 		break;
1271 	}
1272 }
1273 
1274 /*
1275  * The ican3 needs to store all echo skbs, and therefore cannot
1276  * use the generic infrastructure for this.
1277  */
1278 static void ican3_put_echo_skb(struct ican3_dev *mod, struct sk_buff *skb)
1279 {
1280 	skb = can_create_echo_skb(skb);
1281 	if (!skb)
1282 		return;
1283 
1284 	/* save this skb for tx interrupt echo handling */
1285 	skb_queue_tail(&mod->echoq, skb);
1286 }
1287 
1288 static unsigned int ican3_get_echo_skb(struct ican3_dev *mod)
1289 {
1290 	struct sk_buff *skb = skb_dequeue(&mod->echoq);
1291 	struct can_frame *cf;
1292 	u8 dlc;
1293 
1294 	/* this should never trigger unless there is a driver bug */
1295 	if (!skb) {
1296 		netdev_err(mod->ndev, "BUG: echo skb not occupied\n");
1297 		return 0;
1298 	}
1299 
1300 	cf = (struct can_frame *)skb->data;
1301 	dlc = cf->can_dlc;
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->can_dlc != echo_cf->can_dlc)
1340 		return false;
1341 
1342 	return memcmp(cf->data, echo_cf->data, cf->can_dlc) == 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 	stats->rx_bytes += cf->can_dlc;
1429 	netif_receive_skb(skb);
1430 
1431 err_noalloc:
1432 	/* toggle the valid bit and return the descriptor to the ring */
1433 	desc.control ^= DESC_VALID;
1434 
1435 	spin_lock_irqsave(&mod->lock, flags);
1436 
1437 	ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16));
1438 	memcpy_toio(desc_addr, &desc, 1);
1439 
1440 	/* update the next buffer pointer */
1441 	mod->fastrx_num = (desc.control & DESC_WRAP) ? 0
1442 						     : (mod->fastrx_num + 1);
1443 
1444 	/* there are still more buffers to process */
1445 	spin_unlock_irqrestore(&mod->lock, flags);
1446 	return 0;
1447 }
1448 
1449 static int ican3_napi(struct napi_struct *napi, int budget)
1450 {
1451 	struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi);
1452 	unsigned long flags;
1453 	int received = 0;
1454 	int ret;
1455 
1456 	/* process all communication messages */
1457 	while (true) {
1458 		struct ican3_msg uninitialized_var(msg);
1459 		ret = ican3_recv_msg(mod, &msg);
1460 		if (ret)
1461 			break;
1462 
1463 		ican3_handle_message(mod, &msg);
1464 	}
1465 
1466 	/* process all CAN frames from the fast interface */
1467 	while (received < budget) {
1468 		ret = ican3_recv_skb(mod);
1469 		if (ret)
1470 			break;
1471 
1472 		received++;
1473 	}
1474 
1475 	/* We have processed all packets that the adapter had, but it
1476 	 * was less than our budget, stop polling */
1477 	if (received < budget)
1478 		napi_complete_done(napi, received);
1479 
1480 	spin_lock_irqsave(&mod->lock, flags);
1481 
1482 	/* Wake up the transmit queue if necessary */
1483 	if (netif_queue_stopped(mod->ndev) && ican3_txok(mod))
1484 		netif_wake_queue(mod->ndev);
1485 
1486 	spin_unlock_irqrestore(&mod->lock, flags);
1487 
1488 	/* re-enable interrupt generation */
1489 	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1490 	return received;
1491 }
1492 
1493 static irqreturn_t ican3_irq(int irq, void *dev_id)
1494 {
1495 	struct ican3_dev *mod = dev_id;
1496 	u8 stat;
1497 
1498 	/*
1499 	 * The interrupt status register on this device reports interrupts
1500 	 * as zeroes instead of using ones like most other devices
1501 	 */
1502 	stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num);
1503 	if (stat == (1 << mod->num))
1504 		return IRQ_NONE;
1505 
1506 	/* clear the MODULbus interrupt from the microcontroller */
1507 	ioread8(&mod->dpmctrl->interrupt);
1508 
1509 	/* disable interrupt generation, schedule the NAPI poller */
1510 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1511 	napi_schedule(&mod->napi);
1512 	return IRQ_HANDLED;
1513 }
1514 
1515 /*
1516  * Firmware reset, startup, and shutdown
1517  */
1518 
1519 /*
1520  * Reset an ICAN module to its power-on state
1521  *
1522  * CONTEXT: no network device registered
1523  */
1524 static int ican3_reset_module(struct ican3_dev *mod)
1525 {
1526 	unsigned long start;
1527 	u8 runold, runnew;
1528 
1529 	/* disable interrupts so no more work is scheduled */
1530 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1531 
1532 	/* the first unallocated page in the DPM is #9 */
1533 	mod->free_page = DPM_FREE_START;
1534 
1535 	ican3_set_page(mod, QUEUE_OLD_CONTROL);
1536 	runold = ioread8(mod->dpm + TARGET_RUNNING);
1537 
1538 	/* reset the module */
1539 	iowrite8(0x00, &mod->dpmctrl->hwreset);
1540 
1541 	/* wait until the module has finished resetting and is running */
1542 	start = jiffies;
1543 	do {
1544 		ican3_set_page(mod, QUEUE_OLD_CONTROL);
1545 		runnew = ioread8(mod->dpm + TARGET_RUNNING);
1546 		if (runnew == (runold ^ 0xff))
1547 			return 0;
1548 
1549 		msleep(10);
1550 	} while (time_before(jiffies, start + HZ / 2));
1551 
1552 	netdev_err(mod->ndev, "failed to reset CAN module\n");
1553 	return -ETIMEDOUT;
1554 }
1555 
1556 static void ican3_shutdown_module(struct ican3_dev *mod)
1557 {
1558 	ican3_msg_disconnect(mod);
1559 	ican3_reset_module(mod);
1560 }
1561 
1562 /*
1563  * Startup an ICAN module, bringing it into fast mode
1564  */
1565 static int ican3_startup_module(struct ican3_dev *mod)
1566 {
1567 	int ret;
1568 
1569 	ret = ican3_reset_module(mod);
1570 	if (ret) {
1571 		netdev_err(mod->ndev, "unable to reset module\n");
1572 		return ret;
1573 	}
1574 
1575 	/* detect firmware */
1576 	memcpy_fromio(mod->fwinfo, mod->dpm + FIRMWARE_STAMP, sizeof(mod->fwinfo) - 1);
1577 	if (strncmp(mod->fwinfo, "JANZ-ICAN3", 10)) {
1578 		netdev_err(mod->ndev, "ICAN3 not detected (found %s)\n", mod->fwinfo);
1579 		return -ENODEV;
1580 	}
1581 	if (strstr(mod->fwinfo, "CAL/CANopen"))
1582 		mod->fwtype = ICAN3_FWTYPE_CAL_CANOPEN;
1583 	else
1584 		mod->fwtype = ICAN3_FWTYPE_ICANOS;
1585 
1586 	/* re-enable interrupts so we can send messages */
1587 	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1588 
1589 	ret = ican3_msg_connect(mod);
1590 	if (ret) {
1591 		netdev_err(mod->ndev, "unable to connect to module\n");
1592 		return ret;
1593 	}
1594 
1595 	ican3_init_new_host_interface(mod);
1596 	ret = ican3_msg_newhostif(mod);
1597 	if (ret) {
1598 		netdev_err(mod->ndev, "unable to switch to new-style interface\n");
1599 		return ret;
1600 	}
1601 
1602 	/* default to "termination on" */
1603 	ret = ican3_set_termination(mod, true);
1604 	if (ret) {
1605 		netdev_err(mod->ndev, "unable to enable termination\n");
1606 		return ret;
1607 	}
1608 
1609 	/* default to "bus errors enabled" */
1610 	ret = ican3_set_buserror(mod, 1);
1611 	if (ret) {
1612 		netdev_err(mod->ndev, "unable to set bus-error\n");
1613 		return ret;
1614 	}
1615 
1616 	ican3_init_fast_host_interface(mod);
1617 	ret = ican3_msg_fasthostif(mod);
1618 	if (ret) {
1619 		netdev_err(mod->ndev, "unable to switch to fast host interface\n");
1620 		return ret;
1621 	}
1622 
1623 	ret = ican3_set_id_filter(mod, true);
1624 	if (ret) {
1625 		netdev_err(mod->ndev, "unable to set acceptance filter\n");
1626 		return ret;
1627 	}
1628 
1629 	return 0;
1630 }
1631 
1632 /*
1633  * CAN Network Device
1634  */
1635 
1636 static int ican3_open(struct net_device *ndev)
1637 {
1638 	struct ican3_dev *mod = netdev_priv(ndev);
1639 	int ret;
1640 
1641 	/* open the CAN layer */
1642 	ret = open_candev(ndev);
1643 	if (ret) {
1644 		netdev_err(mod->ndev, "unable to start CAN layer\n");
1645 		return ret;
1646 	}
1647 
1648 	/* bring the bus online */
1649 	ret = ican3_set_bus_state(mod, true);
1650 	if (ret) {
1651 		netdev_err(mod->ndev, "unable to set bus-on\n");
1652 		close_candev(ndev);
1653 		return ret;
1654 	}
1655 
1656 	/* start up the network device */
1657 	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1658 	netif_start_queue(ndev);
1659 
1660 	return 0;
1661 }
1662 
1663 static int ican3_stop(struct net_device *ndev)
1664 {
1665 	struct ican3_dev *mod = netdev_priv(ndev);
1666 	int ret;
1667 
1668 	/* stop the network device xmit routine */
1669 	netif_stop_queue(ndev);
1670 	mod->can.state = CAN_STATE_STOPPED;
1671 
1672 	/* bring the bus offline, stop receiving packets */
1673 	ret = ican3_set_bus_state(mod, false);
1674 	if (ret) {
1675 		netdev_err(mod->ndev, "unable to set bus-off\n");
1676 		return ret;
1677 	}
1678 
1679 	/* drop all outstanding echo skbs */
1680 	skb_queue_purge(&mod->echoq);
1681 
1682 	/* close the CAN layer */
1683 	close_candev(ndev);
1684 	return 0;
1685 }
1686 
1687 static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev)
1688 {
1689 	struct ican3_dev *mod = netdev_priv(ndev);
1690 	struct can_frame *cf = (struct can_frame *)skb->data;
1691 	struct ican3_fast_desc desc;
1692 	void __iomem *desc_addr;
1693 	unsigned long flags;
1694 
1695 	if (can_dropped_invalid_skb(ndev, skb))
1696 		return NETDEV_TX_OK;
1697 
1698 	spin_lock_irqsave(&mod->lock, flags);
1699 
1700 	/* check that we can actually transmit */
1701 	if (!ican3_txok(mod)) {
1702 		netdev_err(mod->ndev, "BUG: no free descriptors\n");
1703 		spin_unlock_irqrestore(&mod->lock, flags);
1704 		return NETDEV_TX_BUSY;
1705 	}
1706 
1707 	/* copy the control bits of the descriptor */
1708 	ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16));
1709 	desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc));
1710 	memset(&desc, 0, sizeof(desc));
1711 	memcpy_fromio(&desc, desc_addr, 1);
1712 
1713 	/* convert the Linux CAN frame into ICAN3 format */
1714 	can_frame_to_ican3(mod, cf, &desc);
1715 
1716 	/*
1717 	 * This hardware doesn't have TX-done notifications, so we'll try and
1718 	 * emulate it the best we can using ECHO skbs. Add the skb to the ECHO
1719 	 * stack. Upon packet reception, check if the ECHO skb and received
1720 	 * skb match, and use that to wake the queue.
1721 	 */
1722 	ican3_put_echo_skb(mod, skb);
1723 
1724 	/*
1725 	 * the programming manual says that you must set the IVALID bit, then
1726 	 * interrupt, then set the valid bit. Quite weird, but it seems to be
1727 	 * required for this to work
1728 	 */
1729 	desc.control |= DESC_IVALID;
1730 	memcpy_toio(desc_addr, &desc, sizeof(desc));
1731 
1732 	/* generate a MODULbus interrupt to the microcontroller */
1733 	iowrite8(0x01, &mod->dpmctrl->interrupt);
1734 
1735 	desc.control ^= DESC_VALID;
1736 	memcpy_toio(desc_addr, &desc, sizeof(desc));
1737 
1738 	/* update the next buffer pointer */
1739 	mod->fasttx_num = (desc.control & DESC_WRAP) ? 0
1740 						     : (mod->fasttx_num + 1);
1741 
1742 	/* if there is no free descriptor space, stop the transmit queue */
1743 	if (!ican3_txok(mod))
1744 		netif_stop_queue(ndev);
1745 
1746 	spin_unlock_irqrestore(&mod->lock, flags);
1747 	return NETDEV_TX_OK;
1748 }
1749 
1750 static const struct net_device_ops ican3_netdev_ops = {
1751 	.ndo_open	= ican3_open,
1752 	.ndo_stop	= ican3_stop,
1753 	.ndo_start_xmit	= ican3_xmit,
1754 	.ndo_change_mtu = can_change_mtu,
1755 };
1756 
1757 /*
1758  * Low-level CAN Device
1759  */
1760 
1761 /* This structure was stolen from drivers/net/can/sja1000/sja1000.c */
1762 static const struct can_bittiming_const ican3_bittiming_const = {
1763 	.name = DRV_NAME,
1764 	.tseg1_min = 1,
1765 	.tseg1_max = 16,
1766 	.tseg2_min = 1,
1767 	.tseg2_max = 8,
1768 	.sjw_max = 4,
1769 	.brp_min = 1,
1770 	.brp_max = 64,
1771 	.brp_inc = 1,
1772 };
1773 
1774 static int ican3_set_mode(struct net_device *ndev, enum can_mode mode)
1775 {
1776 	struct ican3_dev *mod = netdev_priv(ndev);
1777 	int ret;
1778 
1779 	if (mode != CAN_MODE_START)
1780 		return -ENOTSUPP;
1781 
1782 	/* bring the bus online */
1783 	ret = ican3_set_bus_state(mod, true);
1784 	if (ret) {
1785 		netdev_err(ndev, "unable to set bus-on\n");
1786 		return ret;
1787 	}
1788 
1789 	/* start up the network device */
1790 	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1791 
1792 	if (netif_queue_stopped(ndev))
1793 		netif_wake_queue(ndev);
1794 
1795 	return 0;
1796 }
1797 
1798 static int ican3_get_berr_counter(const struct net_device *ndev,
1799 				  struct can_berr_counter *bec)
1800 {
1801 	struct ican3_dev *mod = netdev_priv(ndev);
1802 	int ret;
1803 
1804 	ret = ican3_send_inquiry(mod, INQUIRY_STATUS);
1805 	if (ret)
1806 		return ret;
1807 
1808 	if (!wait_for_completion_timeout(&mod->buserror_comp, HZ)) {
1809 		netdev_info(mod->ndev, "%s timed out\n", __func__);
1810 		return -ETIMEDOUT;
1811 	}
1812 
1813 	bec->rxerr = mod->bec.rxerr;
1814 	bec->txerr = mod->bec.txerr;
1815 	return 0;
1816 }
1817 
1818 /*
1819  * Sysfs Attributes
1820  */
1821 
1822 static ssize_t ican3_sysfs_show_term(struct device *dev,
1823 				     struct device_attribute *attr,
1824 				     char *buf)
1825 {
1826 	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1827 	int ret;
1828 
1829 	ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION);
1830 	if (ret)
1831 		return ret;
1832 
1833 	if (!wait_for_completion_timeout(&mod->termination_comp, HZ)) {
1834 		netdev_info(mod->ndev, "%s timed out\n", __func__);
1835 		return -ETIMEDOUT;
1836 	}
1837 
1838 	return snprintf(buf, PAGE_SIZE, "%u\n", mod->termination_enabled);
1839 }
1840 
1841 static ssize_t ican3_sysfs_set_term(struct device *dev,
1842 				    struct device_attribute *attr,
1843 				    const char *buf, size_t count)
1844 {
1845 	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1846 	unsigned long enable;
1847 	int ret;
1848 
1849 	if (kstrtoul(buf, 0, &enable))
1850 		return -EINVAL;
1851 
1852 	ret = ican3_set_termination(mod, enable);
1853 	if (ret)
1854 		return ret;
1855 
1856 	return count;
1857 }
1858 
1859 static ssize_t ican3_sysfs_show_fwinfo(struct device *dev,
1860 				       struct device_attribute *attr,
1861 				       char *buf)
1862 {
1863 	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1864 
1865 	return scnprintf(buf, PAGE_SIZE, "%s\n", mod->fwinfo);
1866 }
1867 
1868 static DEVICE_ATTR(termination, S_IWUSR | S_IRUGO, ican3_sysfs_show_term,
1869 						   ican3_sysfs_set_term);
1870 static DEVICE_ATTR(fwinfo, S_IRUSR | S_IRUGO, ican3_sysfs_show_fwinfo, NULL);
1871 
1872 static struct attribute *ican3_sysfs_attrs[] = {
1873 	&dev_attr_termination.attr,
1874 	&dev_attr_fwinfo.attr,
1875 	NULL,
1876 };
1877 
1878 static struct attribute_group ican3_sysfs_attr_group = {
1879 	.attrs = ican3_sysfs_attrs,
1880 };
1881 
1882 /*
1883  * PCI Subsystem
1884  */
1885 
1886 static int ican3_probe(struct platform_device *pdev)
1887 {
1888 	struct janz_platform_data *pdata;
1889 	struct net_device *ndev;
1890 	struct ican3_dev *mod;
1891 	struct resource *res;
1892 	struct device *dev;
1893 	int ret;
1894 
1895 	pdata = dev_get_platdata(&pdev->dev);
1896 	if (!pdata)
1897 		return -ENXIO;
1898 
1899 	dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno);
1900 
1901 	/* save the struct device for printing */
1902 	dev = &pdev->dev;
1903 
1904 	/* allocate the CAN device and private data */
1905 	ndev = alloc_candev(sizeof(*mod), 0);
1906 	if (!ndev) {
1907 		dev_err(dev, "unable to allocate CANdev\n");
1908 		ret = -ENOMEM;
1909 		goto out_return;
1910 	}
1911 
1912 	platform_set_drvdata(pdev, ndev);
1913 	mod = netdev_priv(ndev);
1914 	mod->ndev = ndev;
1915 	mod->num = pdata->modno;
1916 	netif_napi_add(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS);
1917 	skb_queue_head_init(&mod->echoq);
1918 	spin_lock_init(&mod->lock);
1919 	init_completion(&mod->termination_comp);
1920 	init_completion(&mod->buserror_comp);
1921 
1922 	/* setup device-specific sysfs attributes */
1923 	ndev->sysfs_groups[0] = &ican3_sysfs_attr_group;
1924 
1925 	/* the first unallocated page in the DPM is 9 */
1926 	mod->free_page = DPM_FREE_START;
1927 
1928 	ndev->netdev_ops = &ican3_netdev_ops;
1929 	ndev->flags |= IFF_ECHO;
1930 	SET_NETDEV_DEV(ndev, &pdev->dev);
1931 
1932 	mod->can.clock.freq = ICAN3_CAN_CLOCK;
1933 	mod->can.bittiming_const = &ican3_bittiming_const;
1934 	mod->can.do_set_mode = ican3_set_mode;
1935 	mod->can.do_get_berr_counter = ican3_get_berr_counter;
1936 	mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES
1937 				    | CAN_CTRLMODE_BERR_REPORTING
1938 				    | CAN_CTRLMODE_ONE_SHOT;
1939 
1940 	/* find our IRQ number */
1941 	mod->irq = platform_get_irq(pdev, 0);
1942 	if (mod->irq < 0) {
1943 		dev_err(dev, "IRQ line not found\n");
1944 		ret = -ENODEV;
1945 		goto out_free_ndev;
1946 	}
1947 
1948 	ndev->irq = mod->irq;
1949 
1950 	/* get access to the MODULbus registers for this module */
1951 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1952 	if (!res) {
1953 		dev_err(dev, "MODULbus registers not found\n");
1954 		ret = -ENODEV;
1955 		goto out_free_ndev;
1956 	}
1957 
1958 	mod->dpm = ioremap(res->start, resource_size(res));
1959 	if (!mod->dpm) {
1960 		dev_err(dev, "MODULbus registers not ioremap\n");
1961 		ret = -ENOMEM;
1962 		goto out_free_ndev;
1963 	}
1964 
1965 	mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE;
1966 
1967 	/* get access to the control registers for this module */
1968 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1969 	if (!res) {
1970 		dev_err(dev, "CONTROL registers not found\n");
1971 		ret = -ENODEV;
1972 		goto out_iounmap_dpm;
1973 	}
1974 
1975 	mod->ctrl = ioremap(res->start, resource_size(res));
1976 	if (!mod->ctrl) {
1977 		dev_err(dev, "CONTROL registers not ioremap\n");
1978 		ret = -ENOMEM;
1979 		goto out_iounmap_dpm;
1980 	}
1981 
1982 	/* disable our IRQ, then hookup the IRQ handler */
1983 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1984 	ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod);
1985 	if (ret) {
1986 		dev_err(dev, "unable to request IRQ\n");
1987 		goto out_iounmap_ctrl;
1988 	}
1989 
1990 	/* reset and initialize the CAN controller into fast mode */
1991 	napi_enable(&mod->napi);
1992 	ret = ican3_startup_module(mod);
1993 	if (ret) {
1994 		dev_err(dev, "%s: unable to start CANdev\n", __func__);
1995 		goto out_free_irq;
1996 	}
1997 
1998 	/* register with the Linux CAN layer */
1999 	ret = register_candev(ndev);
2000 	if (ret) {
2001 		dev_err(dev, "%s: unable to register CANdev\n", __func__);
2002 		goto out_free_irq;
2003 	}
2004 
2005 	netdev_info(mod->ndev, "module %d: registered CAN device\n", pdata->modno);
2006 	return 0;
2007 
2008 out_free_irq:
2009 	napi_disable(&mod->napi);
2010 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
2011 	free_irq(mod->irq, mod);
2012 out_iounmap_ctrl:
2013 	iounmap(mod->ctrl);
2014 out_iounmap_dpm:
2015 	iounmap(mod->dpm);
2016 out_free_ndev:
2017 	free_candev(ndev);
2018 out_return:
2019 	return ret;
2020 }
2021 
2022 static int ican3_remove(struct platform_device *pdev)
2023 {
2024 	struct net_device *ndev = platform_get_drvdata(pdev);
2025 	struct ican3_dev *mod = netdev_priv(ndev);
2026 
2027 	/* unregister the netdevice, stop interrupts */
2028 	unregister_netdev(ndev);
2029 	napi_disable(&mod->napi);
2030 	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
2031 	free_irq(mod->irq, mod);
2032 
2033 	/* put the module into reset */
2034 	ican3_shutdown_module(mod);
2035 
2036 	/* unmap all registers */
2037 	iounmap(mod->ctrl);
2038 	iounmap(mod->dpm);
2039 
2040 	free_candev(ndev);
2041 
2042 	return 0;
2043 }
2044 
2045 static struct platform_driver ican3_driver = {
2046 	.driver		= {
2047 		.name	= DRV_NAME,
2048 	},
2049 	.probe		= ican3_probe,
2050 	.remove		= ican3_remove,
2051 };
2052 
2053 module_platform_driver(ican3_driver);
2054 
2055 MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
2056 MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver");
2057 MODULE_LICENSE("GPL");
2058 MODULE_ALIAS("platform:janz-ican3");
2059