janz-ican3.c revision 3d2bdf759f48f9b0a0ffcd798f3e9a3228d6455d
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/init.h>
15#include <linux/interrupt.h>
16#include <linux/delay.h>
17#include <linux/platform_device.h>
18
19#include <linux/netdevice.h>
20#include <linux/can.h>
21#include <linux/can/dev.h>
22#include <linux/can/error.h>
23
24#include <linux/mfd/janz.h>
25
26/* the DPM has 64k of memory, organized into 256x 256 byte pages */
27#define DPM_NUM_PAGES		256
28#define DPM_PAGE_SIZE		256
29#define DPM_PAGE_ADDR(p)	((p) * DPM_PAGE_SIZE)
30
31/* JANZ ICAN3 "old-style" host interface queue page numbers */
32#define QUEUE_OLD_CONTROL	0
33#define QUEUE_OLD_RB0		1
34#define QUEUE_OLD_RB1		2
35#define QUEUE_OLD_WB0		3
36#define QUEUE_OLD_WB1		4
37
38/* Janz ICAN3 "old-style" host interface control registers */
39#define MSYNC_PEER		0x00		/* ICAN only */
40#define MSYNC_LOCL		0x01		/* host only */
41#define TARGET_RUNNING		0x02
42
43#define MSYNC_RB0		0x01
44#define MSYNC_RB1		0x02
45#define MSYNC_RBLW		0x04
46#define MSYNC_RB_MASK		(MSYNC_RB0 | MSYNC_RB1)
47
48#define MSYNC_WB0		0x10
49#define MSYNC_WB1		0x20
50#define MSYNC_WBLW		0x40
51#define MSYNC_WB_MASK		(MSYNC_WB0 | MSYNC_WB1)
52
53/* Janz ICAN3 "new-style" host interface queue page numbers */
54#define QUEUE_TOHOST		5
55#define QUEUE_FROMHOST_MID	6
56#define QUEUE_FROMHOST_HIGH	7
57#define QUEUE_FROMHOST_LOW	8
58
59/* The first free page in the DPM is #9 */
60#define DPM_FREE_START		9
61
62/* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */
63#define DESC_VALID		0x80
64#define DESC_WRAP		0x40
65#define DESC_INTERRUPT		0x20
66#define DESC_IVALID		0x10
67#define DESC_LEN(len)		(len)
68
69/* Janz ICAN3 Firmware Messages */
70#define MSG_CONNECTI		0x02
71#define MSG_DISCONNECT		0x03
72#define MSG_IDVERS		0x04
73#define MSG_MSGLOST		0x05
74#define MSG_NEWHOSTIF		0x08
75#define MSG_INQUIRY		0x0a
76#define MSG_SETAFILMASK		0x10
77#define MSG_INITFDPMQUEUE	0x11
78#define MSG_HWCONF		0x12
79#define MSG_FMSGLOST		0x15
80#define MSG_CEVTIND		0x37
81#define MSG_CBTRREQ		0x41
82#define MSG_COFFREQ		0x42
83#define MSG_CONREQ		0x43
84#define MSG_CCONFREQ		0x47
85
86/*
87 * Janz ICAN3 CAN Inquiry Message Types
88 *
89 * NOTE: there appears to be a firmware bug here. You must send
90 * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED
91 * NOTE: response. The controller never responds to a message with
92 * NOTE: the INQUIRY_EXTENDED subspec :(
93 */
94#define INQUIRY_STATUS		0x00
95#define INQUIRY_TERMINATION	0x01
96#define INQUIRY_EXTENDED	0x04
97
98/* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */
99#define SETAFILMASK_REJECT	0x00
100#define SETAFILMASK_FASTIF	0x02
101
102/* Janz ICAN3 CAN Hardware Configuration Message Types */
103#define HWCONF_TERMINATE_ON	0x01
104#define HWCONF_TERMINATE_OFF	0x00
105
106/* Janz ICAN3 CAN Event Indication Message Types */
107#define CEVTIND_EI		0x01
108#define CEVTIND_DOI		0x02
109#define CEVTIND_LOST		0x04
110#define CEVTIND_FULL		0x08
111#define CEVTIND_BEI		0x10
112
113#define CEVTIND_CHIP_SJA1000	0x02
114
115#define ICAN3_BUSERR_QUOTA_MAX	255
116
117/* Janz ICAN3 CAN Frame Conversion */
118#define ICAN3_ECHO	0x10
119#define ICAN3_EFF_RTR	0x40
120#define ICAN3_SFF_RTR	0x10
121#define ICAN3_EFF	0x80
122
123#define ICAN3_CAN_TYPE_MASK	0x0f
124#define ICAN3_CAN_TYPE_SFF	0x00
125#define ICAN3_CAN_TYPE_EFF	0x01
126
127#define ICAN3_CAN_DLC_MASK	0x0f
128
129/*
130 * SJA1000 Status and Error Register Definitions
131 *
132 * Copied from drivers/net/can/sja1000/sja1000.h
133 */
134
135/* status register content */
136#define SR_BS		0x80
137#define SR_ES		0x40
138#define SR_TS		0x20
139#define SR_RS		0x10
140#define SR_TCS		0x08
141#define SR_TBS		0x04
142#define SR_DOS		0x02
143#define SR_RBS		0x01
144
145#define SR_CRIT (SR_BS|SR_ES)
146
147/* ECC register */
148#define ECC_SEG		0x1F
149#define ECC_DIR		0x20
150#define ECC_ERR		6
151#define ECC_BIT		0x00
152#define ECC_FORM	0x40
153#define ECC_STUFF	0x80
154#define ECC_MASK	0xc0
155
156/* Number of buffers for use in the "new-style" host interface */
157#define ICAN3_NEW_BUFFERS	16
158
159/* Number of buffers for use in the "fast" host interface */
160#define ICAN3_TX_BUFFERS	512
161#define ICAN3_RX_BUFFERS	1024
162
163/* SJA1000 Clock Input */
164#define ICAN3_CAN_CLOCK		8000000
165
166/* Driver Name */
167#define DRV_NAME "janz-ican3"
168
169/* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */
170struct ican3_dpm_control {
171	/* window address register */
172	u8 window_address;
173	u8 unused1;
174
175	/*
176	 * Read access: clear interrupt from microcontroller
177	 * Write access: send interrupt to microcontroller
178	 */
179	u8 interrupt;
180	u8 unused2;
181
182	/* write-only: reset all hardware on the module */
183	u8 hwreset;
184	u8 unused3;
185
186	/* write-only: generate an interrupt to the TPU */
187	u8 tpuinterrupt;
188};
189
190struct ican3_dev {
191
192	/* must be the first member */
193	struct can_priv can;
194
195	/* CAN network device */
196	struct net_device *ndev;
197	struct napi_struct napi;
198
199	/* Device for printing */
200	struct device *dev;
201
202	/* module number */
203	unsigned int num;
204
205	/* base address of registers and IRQ */
206	struct janz_cmodio_onboard_regs __iomem *ctrl;
207	struct ican3_dpm_control __iomem *dpmctrl;
208	void __iomem *dpm;
209	int irq;
210
211	/* CAN bus termination status */
212	struct completion termination_comp;
213	bool termination_enabled;
214
215	/* CAN bus error status registers */
216	struct completion buserror_comp;
217	struct can_berr_counter bec;
218
219	/* old and new style host interface */
220	unsigned int iftype;
221
222	/*
223	 * Any function which changes the current DPM page must hold this
224	 * lock while it is performing data accesses. This ensures that the
225	 * function will not be preempted and end up reading data from a
226	 * different DPM page than it expects.
227	 */
228	spinlock_t lock;
229
230	/* new host interface */
231	unsigned int rx_int;
232	unsigned int rx_num;
233	unsigned int tx_num;
234
235	/* fast host interface */
236	unsigned int fastrx_start;
237	unsigned int fastrx_int;
238	unsigned int fastrx_num;
239	unsigned int fasttx_start;
240	unsigned int fasttx_num;
241
242	/* first free DPM page */
243	unsigned int free_page;
244};
245
246struct ican3_msg {
247	u8 control;
248	u8 spec;
249	__le16 len;
250	u8 data[252];
251};
252
253struct ican3_new_desc {
254	u8 control;
255	u8 pointer;
256};
257
258struct ican3_fast_desc {
259	u8 control;
260	u8 command;
261	u8 data[14];
262};
263
264/* write to the window basic address register */
265static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page)
266{
267	BUG_ON(page >= DPM_NUM_PAGES);
268	iowrite8(page, &mod->dpmctrl->window_address);
269}
270
271/*
272 * ICAN3 "old-style" host interface
273 */
274
275/*
276 * Receive a message from the ICAN3 "old-style" firmware interface
277 *
278 * LOCKING: must hold mod->lock
279 *
280 * returns 0 on success, -ENOMEM when no message exists
281 */
282static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
283{
284	unsigned int mbox, mbox_page;
285	u8 locl, peer, xord;
286
287	/* get the MSYNC registers */
288	ican3_set_page(mod, QUEUE_OLD_CONTROL);
289	peer = ioread8(mod->dpm + MSYNC_PEER);
290	locl = ioread8(mod->dpm + MSYNC_LOCL);
291	xord = locl ^ peer;
292
293	if ((xord & MSYNC_RB_MASK) == 0x00) {
294		dev_dbg(mod->dev, "no mbox for reading\n");
295		return -ENOMEM;
296	}
297
298	/* find the first free mbox to read */
299	if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK)
300		mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1;
301	else
302		mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1;
303
304	/* copy the message */
305	mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1;
306	ican3_set_page(mod, mbox_page);
307	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
308
309	/*
310	 * notify the firmware that the read buffer is available
311	 * for it to fill again
312	 */
313	locl ^= mbox;
314
315	ican3_set_page(mod, QUEUE_OLD_CONTROL);
316	iowrite8(locl, mod->dpm + MSYNC_LOCL);
317	return 0;
318}
319
320/*
321 * Send a message through the "old-style" firmware interface
322 *
323 * LOCKING: must hold mod->lock
324 *
325 * returns 0 on success, -ENOMEM when no free space exists
326 */
327static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
328{
329	unsigned int mbox, mbox_page;
330	u8 locl, peer, xord;
331
332	/* get the MSYNC registers */
333	ican3_set_page(mod, QUEUE_OLD_CONTROL);
334	peer = ioread8(mod->dpm + MSYNC_PEER);
335	locl = ioread8(mod->dpm + MSYNC_LOCL);
336	xord = locl ^ peer;
337
338	if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) {
339		dev_err(mod->dev, "no mbox for writing\n");
340		return -ENOMEM;
341	}
342
343	/* calculate a free mbox to use */
344	mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0;
345
346	/* copy the message to the DPM */
347	mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1;
348	ican3_set_page(mod, mbox_page);
349	memcpy_toio(mod->dpm, msg, sizeof(*msg));
350
351	locl ^= mbox;
352	if (mbox == MSYNC_WB1)
353		locl |= MSYNC_WBLW;
354
355	ican3_set_page(mod, QUEUE_OLD_CONTROL);
356	iowrite8(locl, mod->dpm + MSYNC_LOCL);
357	return 0;
358}
359
360/*
361 * ICAN3 "new-style" Host Interface Setup
362 */
363
364static void __devinit ican3_init_new_host_interface(struct ican3_dev *mod)
365{
366	struct ican3_new_desc desc;
367	unsigned long flags;
368	void __iomem *dst;
369	int i;
370
371	spin_lock_irqsave(&mod->lock, flags);
372
373	/* setup the internal datastructures for RX */
374	mod->rx_num = 0;
375	mod->rx_int = 0;
376
377	/* tohost queue descriptors are in page 5 */
378	ican3_set_page(mod, QUEUE_TOHOST);
379	dst = mod->dpm;
380
381	/* initialize the tohost (rx) queue descriptors: pages 9-24 */
382	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
383		desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */
384		desc.pointer = mod->free_page;
385
386		/* set wrap flag on last buffer */
387		if (i == ICAN3_NEW_BUFFERS - 1)
388			desc.control |= DESC_WRAP;
389
390		memcpy_toio(dst, &desc, sizeof(desc));
391		dst += sizeof(desc);
392		mod->free_page++;
393	}
394
395	/* fromhost (tx) mid queue descriptors are in page 6 */
396	ican3_set_page(mod, QUEUE_FROMHOST_MID);
397	dst = mod->dpm;
398
399	/* setup the internal datastructures for TX */
400	mod->tx_num = 0;
401
402	/* initialize the fromhost mid queue descriptors: pages 25-40 */
403	for (i = 0; i < ICAN3_NEW_BUFFERS; i++) {
404		desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */
405		desc.pointer = mod->free_page;
406
407		/* set wrap flag on last buffer */
408		if (i == ICAN3_NEW_BUFFERS - 1)
409			desc.control |= DESC_WRAP;
410
411		memcpy_toio(dst, &desc, sizeof(desc));
412		dst += sizeof(desc);
413		mod->free_page++;
414	}
415
416	/* fromhost hi queue descriptors are in page 7 */
417	ican3_set_page(mod, QUEUE_FROMHOST_HIGH);
418	dst = mod->dpm;
419
420	/* initialize only a single buffer in the fromhost hi queue (unused) */
421	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
422	desc.pointer = mod->free_page;
423	memcpy_toio(dst, &desc, sizeof(desc));
424	mod->free_page++;
425
426	/* fromhost low queue descriptors are in page 8 */
427	ican3_set_page(mod, QUEUE_FROMHOST_LOW);
428	dst = mod->dpm;
429
430	/* initialize only a single buffer in the fromhost low queue (unused) */
431	desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */
432	desc.pointer = mod->free_page;
433	memcpy_toio(dst, &desc, sizeof(desc));
434	mod->free_page++;
435
436	spin_unlock_irqrestore(&mod->lock, flags);
437}
438
439/*
440 * ICAN3 Fast Host Interface Setup
441 */
442
443static void __devinit ican3_init_fast_host_interface(struct ican3_dev *mod)
444{
445	struct ican3_fast_desc desc;
446	unsigned long flags;
447	unsigned int addr;
448	void __iomem *dst;
449	int i;
450
451	spin_lock_irqsave(&mod->lock, flags);
452
453	/* save the start recv page */
454	mod->fastrx_start = mod->free_page;
455	mod->fastrx_num = 0;
456	mod->fastrx_int = 0;
457
458	/* build a single fast tohost queue descriptor */
459	memset(&desc, 0, sizeof(desc));
460	desc.control = 0x00;
461	desc.command = 1;
462
463	/* build the tohost queue descriptor ring in memory */
464	addr = 0;
465	for (i = 0; i < ICAN3_RX_BUFFERS; i++) {
466
467		/* set the wrap bit on the last buffer */
468		if (i == ICAN3_RX_BUFFERS - 1)
469			desc.control |= DESC_WRAP;
470
471		/* switch to the correct page */
472		ican3_set_page(mod, mod->free_page);
473
474		/* copy the descriptor to the DPM */
475		dst = mod->dpm + addr;
476		memcpy_toio(dst, &desc, sizeof(desc));
477		addr += sizeof(desc);
478
479		/* move to the next page if necessary */
480		if (addr >= DPM_PAGE_SIZE) {
481			addr = 0;
482			mod->free_page++;
483		}
484	}
485
486	/* make sure we page-align the next queue */
487	if (addr != 0)
488		mod->free_page++;
489
490	/* save the start xmit page */
491	mod->fasttx_start = mod->free_page;
492	mod->fasttx_num = 0;
493
494	/* build a single fast fromhost queue descriptor */
495	memset(&desc, 0, sizeof(desc));
496	desc.control = DESC_VALID;
497	desc.command = 1;
498
499	/* build the fromhost queue descriptor ring in memory */
500	addr = 0;
501	for (i = 0; i < ICAN3_TX_BUFFERS; i++) {
502
503		/* set the wrap bit on the last buffer */
504		if (i == ICAN3_TX_BUFFERS - 1)
505			desc.control |= DESC_WRAP;
506
507		/* switch to the correct page */
508		ican3_set_page(mod, mod->free_page);
509
510		/* copy the descriptor to the DPM */
511		dst = mod->dpm + addr;
512		memcpy_toio(dst, &desc, sizeof(desc));
513		addr += sizeof(desc);
514
515		/* move to the next page if necessary */
516		if (addr >= DPM_PAGE_SIZE) {
517			addr = 0;
518			mod->free_page++;
519		}
520	}
521
522	spin_unlock_irqrestore(&mod->lock, flags);
523}
524
525/*
526 * ICAN3 "new-style" Host Interface Message Helpers
527 */
528
529/*
530 * LOCKING: must hold mod->lock
531 */
532static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
533{
534	struct ican3_new_desc desc;
535	void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc));
536
537	/* switch to the fromhost mid queue, and read the buffer descriptor */
538	ican3_set_page(mod, QUEUE_FROMHOST_MID);
539	memcpy_fromio(&desc, desc_addr, sizeof(desc));
540
541	if (!(desc.control & DESC_VALID)) {
542		dev_dbg(mod->dev, "%s: no free buffers\n", __func__);
543		return -ENOMEM;
544	}
545
546	/* switch to the data page, copy the data */
547	ican3_set_page(mod, desc.pointer);
548	memcpy_toio(mod->dpm, msg, sizeof(*msg));
549
550	/* switch back to the descriptor, set the valid bit, write it back */
551	ican3_set_page(mod, QUEUE_FROMHOST_MID);
552	desc.control ^= DESC_VALID;
553	memcpy_toio(desc_addr, &desc, sizeof(desc));
554
555	/* update the tx number */
556	mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1);
557	return 0;
558}
559
560/*
561 * LOCKING: must hold mod->lock
562 */
563static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
564{
565	struct ican3_new_desc desc;
566	void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc));
567
568	/* switch to the tohost queue, and read the buffer descriptor */
569	ican3_set_page(mod, QUEUE_TOHOST);
570	memcpy_fromio(&desc, desc_addr, sizeof(desc));
571
572	if (!(desc.control & DESC_VALID)) {
573		dev_dbg(mod->dev, "%s: no buffers to recv\n", __func__);
574		return -ENOMEM;
575	}
576
577	/* switch to the data page, copy the data */
578	ican3_set_page(mod, desc.pointer);
579	memcpy_fromio(msg, mod->dpm, sizeof(*msg));
580
581	/* switch back to the descriptor, toggle the valid bit, write it back */
582	ican3_set_page(mod, QUEUE_TOHOST);
583	desc.control ^= DESC_VALID;
584	memcpy_toio(desc_addr, &desc, sizeof(desc));
585
586	/* update the rx number */
587	mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1);
588	return 0;
589}
590
591/*
592 * Message Send / Recv Helpers
593 */
594
595static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg)
596{
597	unsigned long flags;
598	int ret;
599
600	spin_lock_irqsave(&mod->lock, flags);
601
602	if (mod->iftype == 0)
603		ret = ican3_old_send_msg(mod, msg);
604	else
605		ret = ican3_new_send_msg(mod, msg);
606
607	spin_unlock_irqrestore(&mod->lock, flags);
608	return ret;
609}
610
611static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg)
612{
613	unsigned long flags;
614	int ret;
615
616	spin_lock_irqsave(&mod->lock, flags);
617
618	if (mod->iftype == 0)
619		ret = ican3_old_recv_msg(mod, msg);
620	else
621		ret = ican3_new_recv_msg(mod, msg);
622
623	spin_unlock_irqrestore(&mod->lock, flags);
624	return ret;
625}
626
627/*
628 * Quick Pre-constructed Messages
629 */
630
631static int __devinit ican3_msg_connect(struct ican3_dev *mod)
632{
633	struct ican3_msg msg;
634
635	memset(&msg, 0, sizeof(msg));
636	msg.spec = MSG_CONNECTI;
637	msg.len = cpu_to_le16(0);
638
639	return ican3_send_msg(mod, &msg);
640}
641
642static int __devexit ican3_msg_disconnect(struct ican3_dev *mod)
643{
644	struct ican3_msg msg;
645
646	memset(&msg, 0, sizeof(msg));
647	msg.spec = MSG_DISCONNECT;
648	msg.len = cpu_to_le16(0);
649
650	return ican3_send_msg(mod, &msg);
651}
652
653static int __devinit ican3_msg_newhostif(struct ican3_dev *mod)
654{
655	struct ican3_msg msg;
656	int ret;
657
658	memset(&msg, 0, sizeof(msg));
659	msg.spec = MSG_NEWHOSTIF;
660	msg.len = cpu_to_le16(0);
661
662	/* If we're not using the old interface, switching seems bogus */
663	WARN_ON(mod->iftype != 0);
664
665	ret = ican3_send_msg(mod, &msg);
666	if (ret)
667		return ret;
668
669	/* mark the module as using the new host interface */
670	mod->iftype = 1;
671	return 0;
672}
673
674static int __devinit ican3_msg_fasthostif(struct ican3_dev *mod)
675{
676	struct ican3_msg msg;
677	unsigned int addr;
678
679	memset(&msg, 0, sizeof(msg));
680	msg.spec = MSG_INITFDPMQUEUE;
681	msg.len = cpu_to_le16(8);
682
683	/* write the tohost queue start address */
684	addr = DPM_PAGE_ADDR(mod->fastrx_start);
685	msg.data[0] = addr & 0xff;
686	msg.data[1] = (addr >> 8) & 0xff;
687	msg.data[2] = (addr >> 16) & 0xff;
688	msg.data[3] = (addr >> 24) & 0xff;
689
690	/* write the fromhost queue start address */
691	addr = DPM_PAGE_ADDR(mod->fasttx_start);
692	msg.data[4] = addr & 0xff;
693	msg.data[5] = (addr >> 8) & 0xff;
694	msg.data[6] = (addr >> 16) & 0xff;
695	msg.data[7] = (addr >> 24) & 0xff;
696
697	/* If we're not using the new interface yet, we cannot do this */
698	WARN_ON(mod->iftype != 1);
699
700	return ican3_send_msg(mod, &msg);
701}
702
703/*
704 * Setup the CAN filter to either accept or reject all
705 * messages from the CAN bus.
706 */
707static int __devinit ican3_set_id_filter(struct ican3_dev *mod, bool accept)
708{
709	struct ican3_msg msg;
710	int ret;
711
712	/* Standard Frame Format */
713	memset(&msg, 0, sizeof(msg));
714	msg.spec = MSG_SETAFILMASK;
715	msg.len = cpu_to_le16(5);
716	msg.data[0] = 0x00; /* IDLo LSB */
717	msg.data[1] = 0x00; /* IDLo MSB */
718	msg.data[2] = 0xff; /* IDHi LSB */
719	msg.data[3] = 0x07; /* IDHi MSB */
720
721	/* accept all frames for fast host if, or reject all frames */
722	msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
723
724	ret = ican3_send_msg(mod, &msg);
725	if (ret)
726		return ret;
727
728	/* Extended Frame Format */
729	memset(&msg, 0, sizeof(msg));
730	msg.spec = MSG_SETAFILMASK;
731	msg.len = cpu_to_le16(13);
732	msg.data[0] = 0;    /* MUX = 0 */
733	msg.data[1] = 0x00; /* IDLo LSB */
734	msg.data[2] = 0x00;
735	msg.data[3] = 0x00;
736	msg.data[4] = 0x20; /* IDLo MSB */
737	msg.data[5] = 0xff; /* IDHi LSB */
738	msg.data[6] = 0xff;
739	msg.data[7] = 0xff;
740	msg.data[8] = 0x3f; /* IDHi MSB */
741
742	/* accept all frames for fast host if, or reject all frames */
743	msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT;
744
745	return ican3_send_msg(mod, &msg);
746}
747
748/*
749 * Bring the CAN bus online or offline
750 */
751static int ican3_set_bus_state(struct ican3_dev *mod, bool on)
752{
753	struct ican3_msg msg;
754
755	memset(&msg, 0, sizeof(msg));
756	msg.spec = on ? MSG_CONREQ : MSG_COFFREQ;
757	msg.len = cpu_to_le16(0);
758
759	return ican3_send_msg(mod, &msg);
760}
761
762static int ican3_set_termination(struct ican3_dev *mod, bool on)
763{
764	struct ican3_msg msg;
765
766	memset(&msg, 0, sizeof(msg));
767	msg.spec = MSG_HWCONF;
768	msg.len = cpu_to_le16(2);
769	msg.data[0] = 0x00;
770	msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF;
771
772	return ican3_send_msg(mod, &msg);
773}
774
775static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec)
776{
777	struct ican3_msg msg;
778
779	memset(&msg, 0, sizeof(msg));
780	msg.spec = MSG_INQUIRY;
781	msg.len = cpu_to_le16(2);
782	msg.data[0] = subspec;
783	msg.data[1] = 0x00;
784
785	return ican3_send_msg(mod, &msg);
786}
787
788static int ican3_set_buserror(struct ican3_dev *mod, u8 quota)
789{
790	struct ican3_msg msg;
791
792	memset(&msg, 0, sizeof(msg));
793	msg.spec = MSG_CCONFREQ;
794	msg.len = cpu_to_le16(2);
795	msg.data[0] = 0x00;
796	msg.data[1] = quota;
797
798	return ican3_send_msg(mod, &msg);
799}
800
801/*
802 * ICAN3 to Linux CAN Frame Conversion
803 */
804
805static void ican3_to_can_frame(struct ican3_dev *mod,
806			       struct ican3_fast_desc *desc,
807			       struct can_frame *cf)
808{
809	if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) {
810		if (desc->data[1] & ICAN3_SFF_RTR)
811			cf->can_id |= CAN_RTR_FLAG;
812
813		cf->can_id |= desc->data[0] << 3;
814		cf->can_id |= (desc->data[1] & 0xe0) >> 5;
815		cf->can_dlc = desc->data[1] & ICAN3_CAN_DLC_MASK;
816		memcpy(cf->data, &desc->data[2], sizeof(cf->data));
817	} else {
818		cf->can_dlc = desc->data[0] & ICAN3_CAN_DLC_MASK;
819		if (desc->data[0] & ICAN3_EFF_RTR)
820			cf->can_id |= CAN_RTR_FLAG;
821
822		if (desc->data[0] & ICAN3_EFF) {
823			cf->can_id |= CAN_EFF_FLAG;
824			cf->can_id |= desc->data[2] << 21; /* 28-21 */
825			cf->can_id |= desc->data[3] << 13; /* 20-13 */
826			cf->can_id |= desc->data[4] << 5;  /* 12-5  */
827			cf->can_id |= (desc->data[5] & 0xf8) >> 3;
828		} else {
829			cf->can_id |= desc->data[2] << 3;  /* 10-3  */
830			cf->can_id |= desc->data[3] >> 5;  /* 2-0   */
831		}
832
833		memcpy(cf->data, &desc->data[6], sizeof(cf->data));
834	}
835}
836
837static void can_frame_to_ican3(struct ican3_dev *mod,
838			       struct can_frame *cf,
839			       struct ican3_fast_desc *desc)
840{
841	/* clear out any stale data in the descriptor */
842	memset(desc->data, 0, sizeof(desc->data));
843
844	/* we always use the extended format, with the ECHO flag set */
845	desc->command = ICAN3_CAN_TYPE_EFF;
846	desc->data[0] |= cf->can_dlc;
847	desc->data[1] |= ICAN3_ECHO;
848
849	if (cf->can_id & CAN_RTR_FLAG)
850		desc->data[0] |= ICAN3_EFF_RTR;
851
852	/* pack the id into the correct places */
853	if (cf->can_id & CAN_EFF_FLAG) {
854		desc->data[0] |= ICAN3_EFF;
855		desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */
856		desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */
857		desc->data[4] = (cf->can_id & 0x00001fe0) >> 5;  /* 12-5  */
858		desc->data[5] = (cf->can_id & 0x0000001f) << 3;  /* 4-0   */
859	} else {
860		desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */
861		desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0  */
862	}
863
864	/* copy the data bits into the descriptor */
865	memcpy(&desc->data[6], cf->data, sizeof(cf->data));
866}
867
868/*
869 * Interrupt Handling
870 */
871
872/*
873 * Handle an ID + Version message response from the firmware. We never generate
874 * this message in production code, but it is very useful when debugging to be
875 * able to display this message.
876 */
877static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg)
878{
879	dev_dbg(mod->dev, "IDVERS response: %s\n", msg->data);
880}
881
882static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg)
883{
884	struct net_device *dev = mod->ndev;
885	struct net_device_stats *stats = &dev->stats;
886	struct can_frame *cf;
887	struct sk_buff *skb;
888
889	/*
890	 * Report that communication messages with the microcontroller firmware
891	 * are being lost. These are never CAN frames, so we do not generate an
892	 * error frame for userspace
893	 */
894	if (msg->spec == MSG_MSGLOST) {
895		dev_err(mod->dev, "lost %d control messages\n", msg->data[0]);
896		return;
897	}
898
899	/*
900	 * Oops, this indicates that we have lost messages in the fast queue,
901	 * which are exclusively CAN messages. Our driver isn't reading CAN
902	 * frames fast enough.
903	 *
904	 * We'll pretend that the SJA1000 told us that it ran out of buffer
905	 * space, because there is not a better message for this.
906	 */
907	skb = alloc_can_err_skb(dev, &cf);
908	if (skb) {
909		cf->can_id |= CAN_ERR_CRTL;
910		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
911		stats->rx_errors++;
912		stats->rx_bytes += cf->can_dlc;
913		netif_rx(skb);
914	}
915}
916
917/*
918 * Handle CAN Event Indication Messages from the firmware
919 *
920 * The ICAN3 firmware provides the values of some SJA1000 registers when it
921 * generates this message. The code below is largely copied from the
922 * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary
923 */
924static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg)
925{
926	struct net_device *dev = mod->ndev;
927	struct net_device_stats *stats = &dev->stats;
928	enum can_state state = mod->can.state;
929	u8 status, isrc, rxerr, txerr;
930	struct can_frame *cf;
931	struct sk_buff *skb;
932
933	/* we can only handle the SJA1000 part */
934	if (msg->data[1] != CEVTIND_CHIP_SJA1000) {
935		dev_err(mod->dev, "unable to handle errors on non-SJA1000\n");
936		return -ENODEV;
937	}
938
939	/* check the message length for sanity */
940	if (le16_to_cpu(msg->len) < 6) {
941		dev_err(mod->dev, "error message too short\n");
942		return -EINVAL;
943	}
944
945	skb = alloc_can_err_skb(dev, &cf);
946	if (skb == NULL)
947		return -ENOMEM;
948
949	isrc = msg->data[0];
950	status = msg->data[3];
951	rxerr = msg->data[4];
952	txerr = msg->data[5];
953
954	/* data overrun interrupt */
955	if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) {
956		dev_dbg(mod->dev, "data overrun interrupt\n");
957		cf->can_id |= CAN_ERR_CRTL;
958		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
959		stats->rx_over_errors++;
960		stats->rx_errors++;
961	}
962
963	/* error warning + passive interrupt */
964	if (isrc == CEVTIND_EI) {
965		dev_dbg(mod->dev, "error warning + passive interrupt\n");
966		if (status & SR_BS) {
967			state = CAN_STATE_BUS_OFF;
968			cf->can_id |= CAN_ERR_BUSOFF;
969			can_bus_off(dev);
970		} else if (status & SR_ES) {
971			if (rxerr >= 128 || txerr >= 128)
972				state = CAN_STATE_ERROR_PASSIVE;
973			else
974				state = CAN_STATE_ERROR_WARNING;
975		} else {
976			state = CAN_STATE_ERROR_ACTIVE;
977		}
978	}
979
980	/* bus error interrupt */
981	if (isrc == CEVTIND_BEI) {
982		u8 ecc = msg->data[2];
983
984		dev_dbg(mod->dev, "bus error interrupt\n");
985		mod->can.can_stats.bus_error++;
986		stats->rx_errors++;
987		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
988
989		switch (ecc & ECC_MASK) {
990		case ECC_BIT:
991			cf->data[2] |= CAN_ERR_PROT_BIT;
992			break;
993		case ECC_FORM:
994			cf->data[2] |= CAN_ERR_PROT_FORM;
995			break;
996		case ECC_STUFF:
997			cf->data[2] |= CAN_ERR_PROT_STUFF;
998			break;
999		default:
1000			cf->data[2] |= CAN_ERR_PROT_UNSPEC;
1001			cf->data[3] = ecc & ECC_SEG;
1002			break;
1003		}
1004
1005		if ((ecc & ECC_DIR) == 0)
1006			cf->data[2] |= CAN_ERR_PROT_TX;
1007
1008		cf->data[6] = txerr;
1009		cf->data[7] = rxerr;
1010	}
1011
1012	if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING ||
1013					state == CAN_STATE_ERROR_PASSIVE)) {
1014		cf->can_id |= CAN_ERR_CRTL;
1015		if (state == CAN_STATE_ERROR_WARNING) {
1016			mod->can.can_stats.error_warning++;
1017			cf->data[1] = (txerr > rxerr) ?
1018				CAN_ERR_CRTL_TX_WARNING :
1019				CAN_ERR_CRTL_RX_WARNING;
1020		} else {
1021			mod->can.can_stats.error_passive++;
1022			cf->data[1] = (txerr > rxerr) ?
1023				CAN_ERR_CRTL_TX_PASSIVE :
1024				CAN_ERR_CRTL_RX_PASSIVE;
1025		}
1026
1027		cf->data[6] = txerr;
1028		cf->data[7] = rxerr;
1029	}
1030
1031	mod->can.state = state;
1032	stats->rx_errors++;
1033	stats->rx_bytes += cf->can_dlc;
1034	netif_rx(skb);
1035	return 0;
1036}
1037
1038static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg)
1039{
1040	switch (msg->data[0]) {
1041	case INQUIRY_STATUS:
1042	case INQUIRY_EXTENDED:
1043		mod->bec.rxerr = msg->data[5];
1044		mod->bec.txerr = msg->data[6];
1045		complete(&mod->buserror_comp);
1046		break;
1047	case INQUIRY_TERMINATION:
1048		mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON;
1049		complete(&mod->termination_comp);
1050		break;
1051	default:
1052		dev_err(mod->dev, "received an unknown inquiry response\n");
1053		break;
1054	}
1055}
1056
1057static void ican3_handle_unknown_message(struct ican3_dev *mod,
1058					struct ican3_msg *msg)
1059{
1060	dev_warn(mod->dev, "received unknown message: spec 0x%.2x length %d\n",
1061			   msg->spec, le16_to_cpu(msg->len));
1062}
1063
1064/*
1065 * Handle a control message from the firmware
1066 */
1067static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg)
1068{
1069	dev_dbg(mod->dev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__,
1070			   mod->num, msg->spec, le16_to_cpu(msg->len));
1071
1072	switch (msg->spec) {
1073	case MSG_IDVERS:
1074		ican3_handle_idvers(mod, msg);
1075		break;
1076	case MSG_MSGLOST:
1077	case MSG_FMSGLOST:
1078		ican3_handle_msglost(mod, msg);
1079		break;
1080	case MSG_CEVTIND:
1081		ican3_handle_cevtind(mod, msg);
1082		break;
1083	case MSG_INQUIRY:
1084		ican3_handle_inquiry(mod, msg);
1085		break;
1086	default:
1087		ican3_handle_unknown_message(mod, msg);
1088		break;
1089	}
1090}
1091
1092/*
1093 * Check that there is room in the TX ring to transmit another skb
1094 *
1095 * LOCKING: must hold mod->lock
1096 */
1097static bool ican3_txok(struct ican3_dev *mod)
1098{
1099	struct ican3_fast_desc __iomem *desc;
1100	u8 control;
1101
1102	/* copy the control bits of the descriptor */
1103	ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16));
1104	desc = mod->dpm + ((mod->fasttx_num % 16) * sizeof(*desc));
1105	control = ioread8(&desc->control);
1106
1107	/* if the control bits are not valid, then we have no more space */
1108	if (!(control & DESC_VALID))
1109		return false;
1110
1111	return true;
1112}
1113
1114/*
1115 * Receive one CAN frame from the hardware
1116 *
1117 * CONTEXT: must be called from user context
1118 */
1119static int ican3_recv_skb(struct ican3_dev *mod)
1120{
1121	struct net_device *ndev = mod->ndev;
1122	struct net_device_stats *stats = &ndev->stats;
1123	struct ican3_fast_desc desc;
1124	void __iomem *desc_addr;
1125	struct can_frame *cf;
1126	struct sk_buff *skb;
1127	unsigned long flags;
1128
1129	spin_lock_irqsave(&mod->lock, flags);
1130
1131	/* copy the whole descriptor */
1132	ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16));
1133	desc_addr = mod->dpm + ((mod->fastrx_num % 16) * sizeof(desc));
1134	memcpy_fromio(&desc, desc_addr, sizeof(desc));
1135
1136	spin_unlock_irqrestore(&mod->lock, flags);
1137
1138	/* check that we actually have a CAN frame */
1139	if (!(desc.control & DESC_VALID))
1140		return -ENOBUFS;
1141
1142	/* allocate an skb */
1143	skb = alloc_can_skb(ndev, &cf);
1144	if (unlikely(skb == NULL)) {
1145		stats->rx_dropped++;
1146		goto err_noalloc;
1147	}
1148
1149	/* convert the ICAN3 frame into Linux CAN format */
1150	ican3_to_can_frame(mod, &desc, cf);
1151
1152	/* receive the skb, update statistics */
1153	netif_receive_skb(skb);
1154	stats->rx_packets++;
1155	stats->rx_bytes += cf->can_dlc;
1156
1157err_noalloc:
1158	/* toggle the valid bit and return the descriptor to the ring */
1159	desc.control ^= DESC_VALID;
1160
1161	spin_lock_irqsave(&mod->lock, flags);
1162
1163	ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16));
1164	memcpy_toio(desc_addr, &desc, 1);
1165
1166	/* update the next buffer pointer */
1167	mod->fastrx_num = (desc.control & DESC_WRAP) ? 0
1168						     : (mod->fastrx_num + 1);
1169
1170	/* there are still more buffers to process */
1171	spin_unlock_irqrestore(&mod->lock, flags);
1172	return 0;
1173}
1174
1175static int ican3_napi(struct napi_struct *napi, int budget)
1176{
1177	struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi);
1178	struct ican3_msg msg;
1179	unsigned long flags;
1180	int received = 0;
1181	int ret;
1182
1183	/* process all communication messages */
1184	while (true) {
1185		ret = ican3_recv_msg(mod, &msg);
1186		if (ret)
1187			break;
1188
1189		ican3_handle_message(mod, &msg);
1190	}
1191
1192	/* process all CAN frames from the fast interface */
1193	while (received < budget) {
1194		ret = ican3_recv_skb(mod);
1195		if (ret)
1196			break;
1197
1198		received++;
1199	}
1200
1201	/* We have processed all packets that the adapter had, but it
1202	 * was less than our budget, stop polling */
1203	if (received < budget)
1204		napi_complete(napi);
1205
1206	spin_lock_irqsave(&mod->lock, flags);
1207
1208	/* Wake up the transmit queue if necessary */
1209	if (netif_queue_stopped(mod->ndev) && ican3_txok(mod))
1210		netif_wake_queue(mod->ndev);
1211
1212	spin_unlock_irqrestore(&mod->lock, flags);
1213
1214	/* re-enable interrupt generation */
1215	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1216	return received;
1217}
1218
1219static irqreturn_t ican3_irq(int irq, void *dev_id)
1220{
1221	struct ican3_dev *mod = dev_id;
1222	u8 stat;
1223
1224	/*
1225	 * The interrupt status register on this device reports interrupts
1226	 * as zeroes instead of using ones like most other devices
1227	 */
1228	stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num);
1229	if (stat == (1 << mod->num))
1230		return IRQ_NONE;
1231
1232	/* clear the MODULbus interrupt from the microcontroller */
1233	ioread8(&mod->dpmctrl->interrupt);
1234
1235	/* disable interrupt generation, schedule the NAPI poller */
1236	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1237	napi_schedule(&mod->napi);
1238	return IRQ_HANDLED;
1239}
1240
1241/*
1242 * Firmware reset, startup, and shutdown
1243 */
1244
1245/*
1246 * Reset an ICAN module to its power-on state
1247 *
1248 * CONTEXT: no network device registered
1249 */
1250static int ican3_reset_module(struct ican3_dev *mod)
1251{
1252	u8 val = 1 << mod->num;
1253	unsigned long start;
1254	u8 runold, runnew;
1255
1256	/* disable interrupts so no more work is scheduled */
1257	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1258
1259	/* the first unallocated page in the DPM is #9 */
1260	mod->free_page = DPM_FREE_START;
1261
1262	ican3_set_page(mod, QUEUE_OLD_CONTROL);
1263	runold = ioread8(mod->dpm + TARGET_RUNNING);
1264
1265	/* reset the module */
1266	iowrite8(val, &mod->ctrl->reset_assert);
1267	iowrite8(val, &mod->ctrl->reset_deassert);
1268
1269	/* wait until the module has finished resetting and is running */
1270	start = jiffies;
1271	do {
1272		ican3_set_page(mod, QUEUE_OLD_CONTROL);
1273		runnew = ioread8(mod->dpm + TARGET_RUNNING);
1274		if (runnew == (runold ^ 0xff))
1275			return 0;
1276
1277		msleep(10);
1278	} while (time_before(jiffies, start + HZ / 4));
1279
1280	dev_err(mod->dev, "failed to reset CAN module\n");
1281	return -ETIMEDOUT;
1282}
1283
1284static void __devexit ican3_shutdown_module(struct ican3_dev *mod)
1285{
1286	ican3_msg_disconnect(mod);
1287	ican3_reset_module(mod);
1288}
1289
1290/*
1291 * Startup an ICAN module, bringing it into fast mode
1292 */
1293static int __devinit ican3_startup_module(struct ican3_dev *mod)
1294{
1295	int ret;
1296
1297	ret = ican3_reset_module(mod);
1298	if (ret) {
1299		dev_err(mod->dev, "unable to reset module\n");
1300		return ret;
1301	}
1302
1303	/* re-enable interrupts so we can send messages */
1304	iowrite8(1 << mod->num, &mod->ctrl->int_enable);
1305
1306	ret = ican3_msg_connect(mod);
1307	if (ret) {
1308		dev_err(mod->dev, "unable to connect to module\n");
1309		return ret;
1310	}
1311
1312	ican3_init_new_host_interface(mod);
1313	ret = ican3_msg_newhostif(mod);
1314	if (ret) {
1315		dev_err(mod->dev, "unable to switch to new-style interface\n");
1316		return ret;
1317	}
1318
1319	/* default to "termination on" */
1320	ret = ican3_set_termination(mod, true);
1321	if (ret) {
1322		dev_err(mod->dev, "unable to enable termination\n");
1323		return ret;
1324	}
1325
1326	/* default to "bus errors enabled" */
1327	ret = ican3_set_buserror(mod, ICAN3_BUSERR_QUOTA_MAX);
1328	if (ret) {
1329		dev_err(mod->dev, "unable to set bus-error\n");
1330		return ret;
1331	}
1332
1333	ican3_init_fast_host_interface(mod);
1334	ret = ican3_msg_fasthostif(mod);
1335	if (ret) {
1336		dev_err(mod->dev, "unable to switch to fast host interface\n");
1337		return ret;
1338	}
1339
1340	ret = ican3_set_id_filter(mod, true);
1341	if (ret) {
1342		dev_err(mod->dev, "unable to set acceptance filter\n");
1343		return ret;
1344	}
1345
1346	return 0;
1347}
1348
1349/*
1350 * CAN Network Device
1351 */
1352
1353static int ican3_open(struct net_device *ndev)
1354{
1355	struct ican3_dev *mod = netdev_priv(ndev);
1356	u8 quota;
1357	int ret;
1358
1359	/* open the CAN layer */
1360	ret = open_candev(ndev);
1361	if (ret) {
1362		dev_err(mod->dev, "unable to start CAN layer\n");
1363		return ret;
1364	}
1365
1366	/* set the bus error generation state appropriately */
1367	if (mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
1368		quota = ICAN3_BUSERR_QUOTA_MAX;
1369	else
1370		quota = 0;
1371
1372	ret = ican3_set_buserror(mod, quota);
1373	if (ret) {
1374		dev_err(mod->dev, "unable to set bus-error\n");
1375		close_candev(ndev);
1376		return ret;
1377	}
1378
1379	/* bring the bus online */
1380	ret = ican3_set_bus_state(mod, true);
1381	if (ret) {
1382		dev_err(mod->dev, "unable to set bus-on\n");
1383		close_candev(ndev);
1384		return ret;
1385	}
1386
1387	/* start up the network device */
1388	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1389	netif_start_queue(ndev);
1390
1391	return 0;
1392}
1393
1394static int ican3_stop(struct net_device *ndev)
1395{
1396	struct ican3_dev *mod = netdev_priv(ndev);
1397	int ret;
1398
1399	/* stop the network device xmit routine */
1400	netif_stop_queue(ndev);
1401	mod->can.state = CAN_STATE_STOPPED;
1402
1403	/* bring the bus offline, stop receiving packets */
1404	ret = ican3_set_bus_state(mod, false);
1405	if (ret) {
1406		dev_err(mod->dev, "unable to set bus-off\n");
1407		return ret;
1408	}
1409
1410	/* close the CAN layer */
1411	close_candev(ndev);
1412	return 0;
1413}
1414
1415static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev)
1416{
1417	struct ican3_dev *mod = netdev_priv(ndev);
1418	struct net_device_stats *stats = &ndev->stats;
1419	struct can_frame *cf = (struct can_frame *)skb->data;
1420	struct ican3_fast_desc desc;
1421	void __iomem *desc_addr;
1422	unsigned long flags;
1423
1424	spin_lock_irqsave(&mod->lock, flags);
1425
1426	/* check that we can actually transmit */
1427	if (!ican3_txok(mod)) {
1428		dev_err(mod->dev, "no free descriptors, stopping queue\n");
1429		netif_stop_queue(ndev);
1430		spin_unlock_irqrestore(&mod->lock, flags);
1431		return NETDEV_TX_BUSY;
1432	}
1433
1434	/* copy the control bits of the descriptor */
1435	ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16));
1436	desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc));
1437	memset(&desc, 0, sizeof(desc));
1438	memcpy_fromio(&desc, desc_addr, 1);
1439
1440	/* convert the Linux CAN frame into ICAN3 format */
1441	can_frame_to_ican3(mod, cf, &desc);
1442
1443	/*
1444	 * the programming manual says that you must set the IVALID bit, then
1445	 * interrupt, then set the valid bit. Quite weird, but it seems to be
1446	 * required for this to work
1447	 */
1448	desc.control |= DESC_IVALID;
1449	memcpy_toio(desc_addr, &desc, sizeof(desc));
1450
1451	/* generate a MODULbus interrupt to the microcontroller */
1452	iowrite8(0x01, &mod->dpmctrl->interrupt);
1453
1454	desc.control ^= DESC_VALID;
1455	memcpy_toio(desc_addr, &desc, sizeof(desc));
1456
1457	/* update the next buffer pointer */
1458	mod->fasttx_num = (desc.control & DESC_WRAP) ? 0
1459						     : (mod->fasttx_num + 1);
1460
1461	/* update statistics */
1462	stats->tx_packets++;
1463	stats->tx_bytes += cf->can_dlc;
1464	kfree_skb(skb);
1465
1466	/*
1467	 * This hardware doesn't have TX-done notifications, so we'll try and
1468	 * emulate it the best we can using ECHO skbs. Get the next TX
1469	 * descriptor, and see if we have room to send. If not, stop the queue.
1470	 * It will be woken when the ECHO skb for the current packet is recv'd.
1471	 */
1472
1473	/* copy the control bits of the descriptor */
1474	if (!ican3_txok(mod))
1475		netif_stop_queue(ndev);
1476
1477	spin_unlock_irqrestore(&mod->lock, flags);
1478	return NETDEV_TX_OK;
1479}
1480
1481static const struct net_device_ops ican3_netdev_ops = {
1482	.ndo_open	= ican3_open,
1483	.ndo_stop	= ican3_stop,
1484	.ndo_start_xmit	= ican3_xmit,
1485};
1486
1487/*
1488 * Low-level CAN Device
1489 */
1490
1491/* This structure was stolen from drivers/net/can/sja1000/sja1000.c */
1492static struct can_bittiming_const ican3_bittiming_const = {
1493	.name = DRV_NAME,
1494	.tseg1_min = 1,
1495	.tseg1_max = 16,
1496	.tseg2_min = 1,
1497	.tseg2_max = 8,
1498	.sjw_max = 4,
1499	.brp_min = 1,
1500	.brp_max = 64,
1501	.brp_inc = 1,
1502};
1503
1504/*
1505 * This routine was stolen from drivers/net/can/sja1000/sja1000.c
1506 *
1507 * The bittiming register command for the ICAN3 just sets the bit timing
1508 * registers on the SJA1000 chip directly
1509 */
1510static int ican3_set_bittiming(struct net_device *ndev)
1511{
1512	struct ican3_dev *mod = netdev_priv(ndev);
1513	struct can_bittiming *bt = &mod->can.bittiming;
1514	struct ican3_msg msg;
1515	u8 btr0, btr1;
1516
1517	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
1518	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
1519		(((bt->phase_seg2 - 1) & 0x7) << 4);
1520	if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1521		btr1 |= 0x80;
1522
1523	memset(&msg, 0, sizeof(msg));
1524	msg.spec = MSG_CBTRREQ;
1525	msg.len = cpu_to_le16(4);
1526	msg.data[0] = 0x00;
1527	msg.data[1] = 0x00;
1528	msg.data[2] = btr0;
1529	msg.data[3] = btr1;
1530
1531	return ican3_send_msg(mod, &msg);
1532}
1533
1534static int ican3_set_mode(struct net_device *ndev, enum can_mode mode)
1535{
1536	struct ican3_dev *mod = netdev_priv(ndev);
1537	int ret;
1538
1539	if (mode != CAN_MODE_START)
1540		return -ENOTSUPP;
1541
1542	/* bring the bus online */
1543	ret = ican3_set_bus_state(mod, true);
1544	if (ret) {
1545		dev_err(mod->dev, "unable to set bus-on\n");
1546		return ret;
1547	}
1548
1549	/* start up the network device */
1550	mod->can.state = CAN_STATE_ERROR_ACTIVE;
1551
1552	if (netif_queue_stopped(ndev))
1553		netif_wake_queue(ndev);
1554
1555	return 0;
1556}
1557
1558static int ican3_get_berr_counter(const struct net_device *ndev,
1559				  struct can_berr_counter *bec)
1560{
1561	struct ican3_dev *mod = netdev_priv(ndev);
1562	int ret;
1563
1564	ret = ican3_send_inquiry(mod, INQUIRY_STATUS);
1565	if (ret)
1566		return ret;
1567
1568	ret = wait_for_completion_timeout(&mod->buserror_comp, HZ);
1569	if (ret <= 0) {
1570		dev_info(mod->dev, "%s timed out\n", __func__);
1571		return -ETIMEDOUT;
1572	}
1573
1574	bec->rxerr = mod->bec.rxerr;
1575	bec->txerr = mod->bec.txerr;
1576	return 0;
1577}
1578
1579/*
1580 * Sysfs Attributes
1581 */
1582
1583static ssize_t ican3_sysfs_show_term(struct device *dev,
1584				     struct device_attribute *attr,
1585				     char *buf)
1586{
1587	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1588	int ret;
1589
1590	ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION);
1591	if (ret)
1592		return ret;
1593
1594	ret = wait_for_completion_timeout(&mod->termination_comp, HZ);
1595	if (ret <= 0) {
1596		dev_info(mod->dev, "%s timed out\n", __func__);
1597		return -ETIMEDOUT;
1598	}
1599
1600	return snprintf(buf, PAGE_SIZE, "%u\n", mod->termination_enabled);
1601}
1602
1603static ssize_t ican3_sysfs_set_term(struct device *dev,
1604				    struct device_attribute *attr,
1605				    const char *buf, size_t count)
1606{
1607	struct ican3_dev *mod = netdev_priv(to_net_dev(dev));
1608	unsigned long enable;
1609	int ret;
1610
1611	if (strict_strtoul(buf, 0, &enable))
1612		return -EINVAL;
1613
1614	ret = ican3_set_termination(mod, enable);
1615	if (ret)
1616		return ret;
1617
1618	return count;
1619}
1620
1621static DEVICE_ATTR(termination, S_IWUSR | S_IRUGO, ican3_sysfs_show_term,
1622						   ican3_sysfs_set_term);
1623
1624static struct attribute *ican3_sysfs_attrs[] = {
1625	&dev_attr_termination.attr,
1626	NULL,
1627};
1628
1629static struct attribute_group ican3_sysfs_attr_group = {
1630	.attrs = ican3_sysfs_attrs,
1631};
1632
1633/*
1634 * PCI Subsystem
1635 */
1636
1637static int __devinit ican3_probe(struct platform_device *pdev)
1638{
1639	struct janz_platform_data *pdata;
1640	struct net_device *ndev;
1641	struct ican3_dev *mod;
1642	struct resource *res;
1643	struct device *dev;
1644	int ret;
1645
1646	pdata = pdev->dev.platform_data;
1647	if (!pdata)
1648		return -ENXIO;
1649
1650	dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno);
1651
1652	/* save the struct device for printing */
1653	dev = &pdev->dev;
1654
1655	/* allocate the CAN device and private data */
1656	ndev = alloc_candev(sizeof(*mod), 0);
1657	if (!ndev) {
1658		dev_err(dev, "unable to allocate CANdev\n");
1659		ret = -ENOMEM;
1660		goto out_return;
1661	}
1662
1663	platform_set_drvdata(pdev, ndev);
1664	mod = netdev_priv(ndev);
1665	mod->ndev = ndev;
1666	mod->dev = &pdev->dev;
1667	mod->num = pdata->modno;
1668	netif_napi_add(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS);
1669	spin_lock_init(&mod->lock);
1670	init_completion(&mod->termination_comp);
1671	init_completion(&mod->buserror_comp);
1672
1673	/* setup device-specific sysfs attributes */
1674	ndev->sysfs_groups[0] = &ican3_sysfs_attr_group;
1675
1676	/* the first unallocated page in the DPM is 9 */
1677	mod->free_page = DPM_FREE_START;
1678
1679	ndev->netdev_ops = &ican3_netdev_ops;
1680	ndev->flags |= IFF_ECHO;
1681	SET_NETDEV_DEV(ndev, &pdev->dev);
1682
1683	mod->can.clock.freq = ICAN3_CAN_CLOCK;
1684	mod->can.bittiming_const = &ican3_bittiming_const;
1685	mod->can.do_set_bittiming = ican3_set_bittiming;
1686	mod->can.do_set_mode = ican3_set_mode;
1687	mod->can.do_get_berr_counter = ican3_get_berr_counter;
1688	mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES
1689				    | CAN_CTRLMODE_BERR_REPORTING;
1690
1691	/* find our IRQ number */
1692	mod->irq = platform_get_irq(pdev, 0);
1693	if (mod->irq < 0) {
1694		dev_err(dev, "IRQ line not found\n");
1695		ret = -ENODEV;
1696		goto out_free_ndev;
1697	}
1698
1699	ndev->irq = mod->irq;
1700
1701	/* get access to the MODULbus registers for this module */
1702	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1703	if (!res) {
1704		dev_err(dev, "MODULbus registers not found\n");
1705		ret = -ENODEV;
1706		goto out_free_ndev;
1707	}
1708
1709	mod->dpm = ioremap(res->start, resource_size(res));
1710	if (!mod->dpm) {
1711		dev_err(dev, "MODULbus registers not ioremap\n");
1712		ret = -ENOMEM;
1713		goto out_free_ndev;
1714	}
1715
1716	mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE;
1717
1718	/* get access to the control registers for this module */
1719	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1720	if (!res) {
1721		dev_err(dev, "CONTROL registers not found\n");
1722		ret = -ENODEV;
1723		goto out_iounmap_dpm;
1724	}
1725
1726	mod->ctrl = ioremap(res->start, resource_size(res));
1727	if (!mod->ctrl) {
1728		dev_err(dev, "CONTROL registers not ioremap\n");
1729		ret = -ENOMEM;
1730		goto out_iounmap_dpm;
1731	}
1732
1733	/* disable our IRQ, then hookup the IRQ handler */
1734	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1735	ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod);
1736	if (ret) {
1737		dev_err(dev, "unable to request IRQ\n");
1738		goto out_iounmap_ctrl;
1739	}
1740
1741	/* reset and initialize the CAN controller into fast mode */
1742	napi_enable(&mod->napi);
1743	ret = ican3_startup_module(mod);
1744	if (ret) {
1745		dev_err(dev, "%s: unable to start CANdev\n", __func__);
1746		goto out_free_irq;
1747	}
1748
1749	/* register with the Linux CAN layer */
1750	ret = register_candev(ndev);
1751	if (ret) {
1752		dev_err(dev, "%s: unable to register CANdev\n", __func__);
1753		goto out_free_irq;
1754	}
1755
1756	dev_info(dev, "module %d: registered CAN device\n", pdata->modno);
1757	return 0;
1758
1759out_free_irq:
1760	napi_disable(&mod->napi);
1761	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1762	free_irq(mod->irq, mod);
1763out_iounmap_ctrl:
1764	iounmap(mod->ctrl);
1765out_iounmap_dpm:
1766	iounmap(mod->dpm);
1767out_free_ndev:
1768	free_candev(ndev);
1769out_return:
1770	return ret;
1771}
1772
1773static int __devexit ican3_remove(struct platform_device *pdev)
1774{
1775	struct net_device *ndev = platform_get_drvdata(pdev);
1776	struct ican3_dev *mod = netdev_priv(ndev);
1777
1778	/* unregister the netdevice, stop interrupts */
1779	unregister_netdev(ndev);
1780	napi_disable(&mod->napi);
1781	iowrite8(1 << mod->num, &mod->ctrl->int_disable);
1782	free_irq(mod->irq, mod);
1783
1784	/* put the module into reset */
1785	ican3_shutdown_module(mod);
1786
1787	/* unmap all registers */
1788	iounmap(mod->ctrl);
1789	iounmap(mod->dpm);
1790
1791	free_candev(ndev);
1792
1793	return 0;
1794}
1795
1796static struct platform_driver ican3_driver = {
1797	.driver		= {
1798		.name	= DRV_NAME,
1799		.owner	= THIS_MODULE,
1800	},
1801	.probe		= ican3_probe,
1802	.remove		= __devexit_p(ican3_remove),
1803};
1804
1805static int __init ican3_init(void)
1806{
1807	return platform_driver_register(&ican3_driver);
1808}
1809
1810static void __exit ican3_exit(void)
1811{
1812	platform_driver_unregister(&ican3_driver);
1813}
1814
1815MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
1816MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver");
1817MODULE_LICENSE("GPL");
1818MODULE_ALIAS("platform:janz-ican3");
1819
1820module_init(ican3_init);
1821module_exit(ican3_exit);
1822