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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Core driver for the CC770 and AN82527 CAN controllers
4 *
5 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/types.h>
15#include <linux/fcntl.h>
16#include <linux/interrupt.h>
17#include <linux/ptrace.h>
18#include <linux/string.h>
19#include <linux/errno.h>
20#include <linux/ethtool.h>
21#include <linux/netdevice.h>
22#include <linux/if_arp.h>
23#include <linux/if_ether.h>
24#include <linux/skbuff.h>
25#include <linux/delay.h>
26
27#include <linux/can.h>
28#include <linux/can/dev.h>
29#include <linux/can/error.h>
30#include <linux/can/platform/cc770.h>
31
32#include "cc770.h"
33
34MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
35MODULE_LICENSE("GPL v2");
36MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
37
38/*
39 * The CC770 is a CAN controller from Bosch, which is 100% compatible
40 * with the AN82527 from Intel, but with "bugs" being fixed and some
41 * additional functionality, mainly:
42 *
43 * 1. RX and TX error counters are readable.
44 * 2. Support of silent (listen-only) mode.
45 * 3. Message object 15 can receive all types of frames, also RTR and EFF.
46 *
47 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
48 * which explains in detail the compatibility between the CC770 and the
49 * 82527. This driver use the additional functionality 3. on real CC770
50 * devices. Unfortunately, the CC770 does still not store the message
51 * identifier of received remote transmission request frames and
52 * therefore it's set to 0.
53 *
54 * The message objects 1..14 can be used for TX and RX while the message
55 * objects 15 is optimized for RX. It has a shadow register for reliable
56 * data reception under heavy bus load. Therefore it makes sense to use
57 * this message object for the needed use case. The frame type (EFF/SFF)
58 * for the message object 15 can be defined via kernel module parameter
59 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
60 * otherwise 11 bit SFF messages.
61 */
62static int msgobj15_eff;
63module_param(msgobj15_eff, int, 0444);
64MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
65 "(default: 11-bit standard frames)");
66
67static int i82527_compat;
68module_param(i82527_compat, int, 0444);
69MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 compatibility mode "
70 "without using additional functions");
71
72/*
73 * This driver uses the last 5 message objects 11..15. The definitions
74 * and structure below allows to configure and assign them to the real
75 * message object.
76 */
77static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
78 [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
79 [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
80 [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
81 [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
82 CC770_OBJ_FLAG_EFF,
83 [CC770_OBJ_TX] = 0,
84};
85
86static const struct can_bittiming_const cc770_bittiming_const = {
87 .name = KBUILD_MODNAME,
88 .tseg1_min = 1,
89 .tseg1_max = 16,
90 .tseg2_min = 1,
91 .tseg2_max = 8,
92 .sjw_max = 4,
93 .brp_min = 1,
94 .brp_max = 64,
95 .brp_inc = 1,
96};
97
98static inline int intid2obj(unsigned int intid)
99{
100 if (intid == 2)
101 return 0;
102 else
103 return MSGOBJ_LAST + 2 - intid;
104}
105
106static void enable_all_objs(const struct net_device *dev)
107{
108 struct cc770_priv *priv = netdev_priv(dev);
109 u8 msgcfg;
110 unsigned char obj_flags;
111 unsigned int o, mo;
112
113 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
114 obj_flags = priv->obj_flags[o];
115 mo = obj2msgobj(o);
116
117 if (obj_flags & CC770_OBJ_FLAG_RX) {
118 /*
119 * We don't need extra objects for RTR and EFF if
120 * the additional CC770 functions are enabled.
121 */
122 if (priv->control_normal_mode & CTRL_EAF) {
123 if (o > 0)
124 continue;
125 netdev_dbg(dev, "Message object %d for "
126 "RX data, RTR, SFF and EFF\n", mo);
127 } else {
128 netdev_dbg(dev,
129 "Message object %d for RX %s %s\n",
130 mo, obj_flags & CC770_OBJ_FLAG_RTR ?
131 "RTR" : "data",
132 obj_flags & CC770_OBJ_FLAG_EFF ?
133 "EFF" : "SFF");
134 }
135
136 if (obj_flags & CC770_OBJ_FLAG_EFF)
137 msgcfg = MSGCFG_XTD;
138 else
139 msgcfg = 0;
140 if (obj_flags & CC770_OBJ_FLAG_RTR)
141 msgcfg |= MSGCFG_DIR;
142
143 cc770_write_reg(priv, msgobj[mo].config, msgcfg);
144 cc770_write_reg(priv, msgobj[mo].ctrl0,
145 MSGVAL_SET | TXIE_RES |
146 RXIE_SET | INTPND_RES);
147
148 if (obj_flags & CC770_OBJ_FLAG_RTR)
149 cc770_write_reg(priv, msgobj[mo].ctrl1,
150 NEWDAT_RES | CPUUPD_SET |
151 TXRQST_RES | RMTPND_RES);
152 else
153 cc770_write_reg(priv, msgobj[mo].ctrl1,
154 NEWDAT_RES | MSGLST_RES |
155 TXRQST_RES | RMTPND_RES);
156 } else {
157 netdev_dbg(dev, "Message object %d for "
158 "TX data, RTR, SFF and EFF\n", mo);
159
160 cc770_write_reg(priv, msgobj[mo].ctrl1,
161 RMTPND_RES | TXRQST_RES |
162 CPUUPD_RES | NEWDAT_RES);
163 cc770_write_reg(priv, msgobj[mo].ctrl0,
164 MSGVAL_RES | TXIE_RES |
165 RXIE_RES | INTPND_RES);
166 }
167 }
168}
169
170static void disable_all_objs(const struct cc770_priv *priv)
171{
172 int o, mo;
173
174 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
175 mo = obj2msgobj(o);
176
177 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
178 if (o > 0 && priv->control_normal_mode & CTRL_EAF)
179 continue;
180
181 cc770_write_reg(priv, msgobj[mo].ctrl1,
182 NEWDAT_RES | MSGLST_RES |
183 TXRQST_RES | RMTPND_RES);
184 cc770_write_reg(priv, msgobj[mo].ctrl0,
185 MSGVAL_RES | TXIE_RES |
186 RXIE_RES | INTPND_RES);
187 } else {
188 /* Clear message object for send */
189 cc770_write_reg(priv, msgobj[mo].ctrl1,
190 RMTPND_RES | TXRQST_RES |
191 CPUUPD_RES | NEWDAT_RES);
192 cc770_write_reg(priv, msgobj[mo].ctrl0,
193 MSGVAL_RES | TXIE_RES |
194 RXIE_RES | INTPND_RES);
195 }
196 }
197}
198
199static void set_reset_mode(struct net_device *dev)
200{
201 struct cc770_priv *priv = netdev_priv(dev);
202
203 /* Enable configuration and puts chip in bus-off, disable interrupts */
204 cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
205
206 priv->can.state = CAN_STATE_STOPPED;
207
208 /* Clear interrupts */
209 cc770_read_reg(priv, interrupt);
210
211 /* Clear status register */
212 cc770_write_reg(priv, status, 0);
213
214 /* Disable all used message objects */
215 disable_all_objs(priv);
216}
217
218static void set_normal_mode(struct net_device *dev)
219{
220 struct cc770_priv *priv = netdev_priv(dev);
221
222 /* Clear interrupts */
223 cc770_read_reg(priv, interrupt);
224
225 /* Clear status register and pre-set last error code */
226 cc770_write_reg(priv, status, STAT_LEC_MASK);
227
228 /* Enable all used message objects*/
229 enable_all_objs(dev);
230
231 /*
232 * Clear bus-off, interrupts only for errors,
233 * not for status change
234 */
235 cc770_write_reg(priv, control, priv->control_normal_mode);
236
237 priv->can.state = CAN_STATE_ERROR_ACTIVE;
238}
239
240static void chipset_init(struct cc770_priv *priv)
241{
242 int mo, id, data;
243
244 /* Enable configuration and put chip in bus-off, disable interrupts */
245 cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
246
247 /* Set CLKOUT divider and slew rates */
248 cc770_write_reg(priv, clkout, priv->clkout);
249
250 /* Configure CPU interface / CLKOUT enable */
251 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
252
253 /* Set bus configuration */
254 cc770_write_reg(priv, bus_config, priv->bus_config);
255
256 /* Clear interrupts */
257 cc770_read_reg(priv, interrupt);
258
259 /* Clear status register */
260 cc770_write_reg(priv, status, 0);
261
262 /* Clear and invalidate message objects */
263 for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
264 cc770_write_reg(priv, msgobj[mo].ctrl0,
265 INTPND_UNC | RXIE_RES |
266 TXIE_RES | MSGVAL_RES);
267 cc770_write_reg(priv, msgobj[mo].ctrl0,
268 INTPND_RES | RXIE_RES |
269 TXIE_RES | MSGVAL_RES);
270 cc770_write_reg(priv, msgobj[mo].ctrl1,
271 NEWDAT_RES | MSGLST_RES |
272 TXRQST_RES | RMTPND_RES);
273 for (data = 0; data < 8; data++)
274 cc770_write_reg(priv, msgobj[mo].data[data], 0);
275 for (id = 0; id < 4; id++)
276 cc770_write_reg(priv, msgobj[mo].id[id], 0);
277 cc770_write_reg(priv, msgobj[mo].config, 0);
278 }
279
280 /* Set all global ID masks to "don't care" */
281 cc770_write_reg(priv, global_mask_std[0], 0);
282 cc770_write_reg(priv, global_mask_std[1], 0);
283 cc770_write_reg(priv, global_mask_ext[0], 0);
284 cc770_write_reg(priv, global_mask_ext[1], 0);
285 cc770_write_reg(priv, global_mask_ext[2], 0);
286 cc770_write_reg(priv, global_mask_ext[3], 0);
287
288}
289
290static int cc770_probe_chip(struct net_device *dev)
291{
292 struct cc770_priv *priv = netdev_priv(dev);
293
294 /* Enable configuration, put chip in bus-off, disable ints */
295 cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
296 /* Configure cpu interface / CLKOUT disable */
297 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
298
299 /*
300 * Check if hardware reset is still inactive or maybe there
301 * is no chip in this address space
302 */
303 if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
304 netdev_info(dev, "probing @0x%p failed (reset)\n",
305 priv->reg_base);
306 return -ENODEV;
307 }
308
309 /* Write and read back test pattern (some arbitrary values) */
310 cc770_write_reg(priv, msgobj[1].data[1], 0x25);
311 cc770_write_reg(priv, msgobj[2].data[3], 0x52);
312 cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
313 if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
314 (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
315 (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
316 netdev_info(dev, "probing @0x%p failed (pattern)\n",
317 priv->reg_base);
318 return -ENODEV;
319 }
320
321 /* Check if this chip is a CC770 supporting additional functions */
322 if (cc770_read_reg(priv, control) & CTRL_EAF)
323 priv->control_normal_mode |= CTRL_EAF;
324
325 return 0;
326}
327
328static void cc770_start(struct net_device *dev)
329{
330 struct cc770_priv *priv = netdev_priv(dev);
331
332 /* leave reset mode */
333 if (priv->can.state != CAN_STATE_STOPPED)
334 set_reset_mode(dev);
335
336 /* leave reset mode */
337 set_normal_mode(dev);
338}
339
340static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
341{
342 switch (mode) {
343 case CAN_MODE_START:
344 cc770_start(dev);
345 netif_wake_queue(dev);
346 break;
347
348 default:
349 return -EOPNOTSUPP;
350 }
351
352 return 0;
353}
354
355static int cc770_set_bittiming(struct net_device *dev)
356{
357 struct cc770_priv *priv = netdev_priv(dev);
358 struct can_bittiming *bt = &priv->can.bittiming;
359 u8 btr0, btr1;
360
361 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
362 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
363 (((bt->phase_seg2 - 1) & 0x7) << 4);
364 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
365 btr1 |= 0x80;
366
367 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
368
369 cc770_write_reg(priv, bit_timing_0, btr0);
370 cc770_write_reg(priv, bit_timing_1, btr1);
371
372 return 0;
373}
374
375static int cc770_get_berr_counter(const struct net_device *dev,
376 struct can_berr_counter *bec)
377{
378 struct cc770_priv *priv = netdev_priv(dev);
379
380 bec->txerr = cc770_read_reg(priv, tx_error_counter);
381 bec->rxerr = cc770_read_reg(priv, rx_error_counter);
382
383 return 0;
384}
385
386static void cc770_tx(struct net_device *dev, int mo)
387{
388 struct cc770_priv *priv = netdev_priv(dev);
389 struct can_frame *cf = (struct can_frame *)priv->tx_skb->data;
390 u8 dlc, rtr;
391 u32 id;
392 int i;
393
394 dlc = cf->len;
395 id = cf->can_id;
396 rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR;
397
398 cc770_write_reg(priv, msgobj[mo].ctrl0,
399 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
400 cc770_write_reg(priv, msgobj[mo].ctrl1,
401 RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
402
403 if (id & CAN_EFF_FLAG) {
404 id &= CAN_EFF_MASK;
405 cc770_write_reg(priv, msgobj[mo].config,
406 (dlc << 4) | rtr | MSGCFG_XTD);
407 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
408 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
409 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
410 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
411 } else {
412 id &= CAN_SFF_MASK;
413 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
414 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
415 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
416 }
417
418 for (i = 0; i < dlc; i++)
419 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
420
421 cc770_write_reg(priv, msgobj[mo].ctrl1,
422 RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
423 cc770_write_reg(priv, msgobj[mo].ctrl0,
424 MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC);
425}
426
427static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
428{
429 struct cc770_priv *priv = netdev_priv(dev);
430 unsigned int mo = obj2msgobj(CC770_OBJ_TX);
431
432 if (can_dev_dropped_skb(dev, skb))
433 return NETDEV_TX_OK;
434
435 netif_stop_queue(dev);
436
437 if ((cc770_read_reg(priv,
438 msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
439 netdev_err(dev, "TX register is still occupied!\n");
440 return NETDEV_TX_BUSY;
441 }
442
443 priv->tx_skb = skb;
444 cc770_tx(dev, mo);
445
446 return NETDEV_TX_OK;
447}
448
449static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
450{
451 struct cc770_priv *priv = netdev_priv(dev);
452 struct net_device_stats *stats = &dev->stats;
453 struct can_frame *cf;
454 struct sk_buff *skb;
455 u8 config;
456 u32 id;
457 int i;
458
459 skb = alloc_can_skb(dev, &cf);
460 if (!skb)
461 return;
462
463 config = cc770_read_reg(priv, msgobj[mo].config);
464
465 if (ctrl1 & RMTPND_SET) {
466 /*
467 * Unfortunately, the chip does not store the real message
468 * identifier of the received remote transmission request
469 * frame. Therefore we set it to 0.
470 */
471 cf->can_id = CAN_RTR_FLAG;
472 if (config & MSGCFG_XTD)
473 cf->can_id |= CAN_EFF_FLAG;
474 cf->len = 0;
475 } else {
476 if (config & MSGCFG_XTD) {
477 id = cc770_read_reg(priv, msgobj[mo].id[3]);
478 id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
479 id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
480 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
481 id >>= 3;
482 id |= CAN_EFF_FLAG;
483 } else {
484 id = cc770_read_reg(priv, msgobj[mo].id[1]);
485 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
486 id >>= 5;
487 }
488
489 cf->can_id = id;
490 cf->len = can_cc_dlc2len((config & 0xf0) >> 4);
491 for (i = 0; i < cf->len; i++)
492 cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
493
494 stats->rx_bytes += cf->len;
495 }
496 stats->rx_packets++;
497
498 netif_rx(skb);
499}
500
501static int cc770_err(struct net_device *dev, u8 status)
502{
503 struct cc770_priv *priv = netdev_priv(dev);
504 struct can_frame *cf;
505 struct sk_buff *skb;
506 u8 lec;
507
508 netdev_dbg(dev, "status interrupt (%#x)\n", status);
509
510 skb = alloc_can_err_skb(dev, &cf);
511 if (!skb)
512 return -ENOMEM;
513
514 /* Use extended functions of the CC770 */
515 if (priv->control_normal_mode & CTRL_EAF) {
516 cf->can_id |= CAN_ERR_CNT;
517 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
518 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
519 }
520
521 if (status & STAT_BOFF) {
522 /* Disable interrupts */
523 cc770_write_reg(priv, control, CTRL_INI);
524 cf->can_id |= CAN_ERR_BUSOFF;
525 priv->can.state = CAN_STATE_BUS_OFF;
526 priv->can.can_stats.bus_off++;
527 can_bus_off(dev);
528 } else if (status & STAT_WARN) {
529 cf->can_id |= CAN_ERR_CRTL;
530 /* Only the CC770 does show error passive */
531 if (cf->data[7] > 127) {
532 cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
533 CAN_ERR_CRTL_TX_PASSIVE;
534 priv->can.state = CAN_STATE_ERROR_PASSIVE;
535 priv->can.can_stats.error_passive++;
536 } else {
537 cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
538 CAN_ERR_CRTL_TX_WARNING;
539 priv->can.state = CAN_STATE_ERROR_WARNING;
540 priv->can.can_stats.error_warning++;
541 }
542 } else {
543 /* Back to error active */
544 cf->can_id |= CAN_ERR_PROT;
545 cf->data[2] = CAN_ERR_PROT_ACTIVE;
546 priv->can.state = CAN_STATE_ERROR_ACTIVE;
547 }
548
549 lec = status & STAT_LEC_MASK;
550 if (lec < 7 && lec > 0) {
551 if (lec == STAT_LEC_ACK) {
552 cf->can_id |= CAN_ERR_ACK;
553 } else {
554 cf->can_id |= CAN_ERR_PROT;
555 switch (lec) {
556 case STAT_LEC_STUFF:
557 cf->data[2] |= CAN_ERR_PROT_STUFF;
558 break;
559 case STAT_LEC_FORM:
560 cf->data[2] |= CAN_ERR_PROT_FORM;
561 break;
562 case STAT_LEC_BIT1:
563 cf->data[2] |= CAN_ERR_PROT_BIT1;
564 break;
565 case STAT_LEC_BIT0:
566 cf->data[2] |= CAN_ERR_PROT_BIT0;
567 break;
568 case STAT_LEC_CRC:
569 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
570 break;
571 }
572 }
573 }
574
575
576 netif_rx(skb);
577
578 return 0;
579}
580
581static int cc770_status_interrupt(struct net_device *dev)
582{
583 struct cc770_priv *priv = netdev_priv(dev);
584 u8 status;
585
586 status = cc770_read_reg(priv, status);
587 /* Reset the status register including RXOK and TXOK */
588 cc770_write_reg(priv, status, STAT_LEC_MASK);
589
590 if (status & (STAT_WARN | STAT_BOFF) ||
591 (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
592 cc770_err(dev, status);
593 return status & STAT_BOFF;
594 }
595
596 return 0;
597}
598
599static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
600{
601 struct cc770_priv *priv = netdev_priv(dev);
602 struct net_device_stats *stats = &dev->stats;
603 unsigned int mo = obj2msgobj(o);
604 u8 ctrl1;
605 int n = CC770_MAX_MSG;
606
607 while (n--) {
608 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
609
610 if (!(ctrl1 & NEWDAT_SET)) {
611 /* Check for RTR if additional functions are enabled */
612 if (priv->control_normal_mode & CTRL_EAF) {
613 if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
614 INTPND_SET))
615 break;
616 } else {
617 break;
618 }
619 }
620
621 if (ctrl1 & MSGLST_SET) {
622 stats->rx_over_errors++;
623 stats->rx_errors++;
624 }
625 if (mo < MSGOBJ_LAST)
626 cc770_write_reg(priv, msgobj[mo].ctrl1,
627 NEWDAT_RES | MSGLST_RES |
628 TXRQST_UNC | RMTPND_UNC);
629 cc770_rx(dev, mo, ctrl1);
630
631 cc770_write_reg(priv, msgobj[mo].ctrl0,
632 MSGVAL_SET | TXIE_RES |
633 RXIE_SET | INTPND_RES);
634 cc770_write_reg(priv, msgobj[mo].ctrl1,
635 NEWDAT_RES | MSGLST_RES |
636 TXRQST_RES | RMTPND_RES);
637 }
638}
639
640static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
641{
642 struct cc770_priv *priv = netdev_priv(dev);
643 unsigned int mo = obj2msgobj(o);
644 u8 ctrl0, ctrl1;
645 int n = CC770_MAX_MSG;
646
647 while (n--) {
648 ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
649 if (!(ctrl0 & INTPND_SET))
650 break;
651
652 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
653 cc770_rx(dev, mo, ctrl1);
654
655 cc770_write_reg(priv, msgobj[mo].ctrl0,
656 MSGVAL_SET | TXIE_RES |
657 RXIE_SET | INTPND_RES);
658 cc770_write_reg(priv, msgobj[mo].ctrl1,
659 NEWDAT_RES | CPUUPD_SET |
660 TXRQST_RES | RMTPND_RES);
661 }
662}
663
664static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
665{
666 struct cc770_priv *priv = netdev_priv(dev);
667 struct net_device_stats *stats = &dev->stats;
668 unsigned int mo = obj2msgobj(o);
669 u8 ctrl1;
670
671 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
672
673 cc770_write_reg(priv, msgobj[mo].ctrl0,
674 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
675 cc770_write_reg(priv, msgobj[mo].ctrl1,
676 RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES);
677
678 if (unlikely(!priv->tx_skb)) {
679 netdev_err(dev, "missing tx skb in tx interrupt\n");
680 return;
681 }
682
683 if (unlikely(ctrl1 & MSGLST_SET)) {
684 stats->rx_over_errors++;
685 stats->rx_errors++;
686 }
687
688 /* When the CC770 is sending an RTR message and it receives a regular
689 * message that matches the id of the RTR message, it will overwrite the
690 * outgoing message in the TX register. When this happens we must
691 * process the received message and try to transmit the outgoing skb
692 * again.
693 */
694 if (unlikely(ctrl1 & NEWDAT_SET)) {
695 cc770_rx(dev, mo, ctrl1);
696 cc770_tx(dev, mo);
697 return;
698 }
699
700 can_put_echo_skb(priv->tx_skb, dev, 0, 0);
701 stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
702 stats->tx_packets++;
703 priv->tx_skb = NULL;
704
705 netif_wake_queue(dev);
706}
707
708static irqreturn_t cc770_interrupt(int irq, void *dev_id)
709{
710 struct net_device *dev = (struct net_device *)dev_id;
711 struct cc770_priv *priv = netdev_priv(dev);
712 u8 intid;
713 int o, n = 0;
714
715 /* Shared interrupts and IRQ off? */
716 if (priv->can.state == CAN_STATE_STOPPED)
717 return IRQ_NONE;
718
719 if (priv->pre_irq)
720 priv->pre_irq(priv);
721
722 while (n < CC770_MAX_IRQ) {
723 /* Read the highest pending interrupt request */
724 intid = cc770_read_reg(priv, interrupt);
725 if (!intid)
726 break;
727 n++;
728
729 if (intid == 1) {
730 /* Exit in case of bus-off */
731 if (cc770_status_interrupt(dev))
732 break;
733 } else {
734 o = intid2obj(intid);
735
736 if (o >= CC770_OBJ_MAX) {
737 netdev_err(dev, "Unexpected interrupt id %d\n",
738 intid);
739 continue;
740 }
741
742 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
743 cc770_rtr_interrupt(dev, o);
744 else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
745 cc770_rx_interrupt(dev, o);
746 else
747 cc770_tx_interrupt(dev, o);
748 }
749 }
750
751 if (priv->post_irq)
752 priv->post_irq(priv);
753
754 if (n >= CC770_MAX_IRQ)
755 netdev_dbg(dev, "%d messages handled in ISR", n);
756
757 return (n) ? IRQ_HANDLED : IRQ_NONE;
758}
759
760static int cc770_open(struct net_device *dev)
761{
762 struct cc770_priv *priv = netdev_priv(dev);
763 int err;
764
765 /* set chip into reset mode */
766 set_reset_mode(dev);
767
768 /* common open */
769 err = open_candev(dev);
770 if (err)
771 return err;
772
773 err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
774 dev->name, dev);
775 if (err) {
776 close_candev(dev);
777 return -EAGAIN;
778 }
779
780 /* init and start chip */
781 cc770_start(dev);
782
783 netif_start_queue(dev);
784
785 return 0;
786}
787
788static int cc770_close(struct net_device *dev)
789{
790 netif_stop_queue(dev);
791 set_reset_mode(dev);
792
793 free_irq(dev->irq, dev);
794 close_candev(dev);
795
796 return 0;
797}
798
799struct net_device *alloc_cc770dev(int sizeof_priv)
800{
801 struct net_device *dev;
802 struct cc770_priv *priv;
803
804 dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
805 CC770_ECHO_SKB_MAX);
806 if (!dev)
807 return NULL;
808
809 priv = netdev_priv(dev);
810
811 priv->dev = dev;
812 priv->can.bittiming_const = &cc770_bittiming_const;
813 priv->can.do_set_bittiming = cc770_set_bittiming;
814 priv->can.do_set_mode = cc770_set_mode;
815 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
816 priv->tx_skb = NULL;
817
818 memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
819
820 if (sizeof_priv)
821 priv->priv = (void *)priv + sizeof(struct cc770_priv);
822
823 return dev;
824}
825EXPORT_SYMBOL_GPL(alloc_cc770dev);
826
827void free_cc770dev(struct net_device *dev)
828{
829 free_candev(dev);
830}
831EXPORT_SYMBOL_GPL(free_cc770dev);
832
833static const struct net_device_ops cc770_netdev_ops = {
834 .ndo_open = cc770_open,
835 .ndo_stop = cc770_close,
836 .ndo_start_xmit = cc770_start_xmit,
837 .ndo_change_mtu = can_change_mtu,
838};
839
840static const struct ethtool_ops cc770_ethtool_ops = {
841 .get_ts_info = ethtool_op_get_ts_info,
842};
843
844int register_cc770dev(struct net_device *dev)
845{
846 struct cc770_priv *priv = netdev_priv(dev);
847 int err;
848
849 err = cc770_probe_chip(dev);
850 if (err)
851 return err;
852
853 dev->netdev_ops = &cc770_netdev_ops;
854 dev->ethtool_ops = &cc770_ethtool_ops;
855
856 dev->flags |= IFF_ECHO; /* we support local echo */
857
858 /* Should we use additional functions? */
859 if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
860 priv->can.do_get_berr_counter = cc770_get_berr_counter;
861 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
862 netdev_dbg(dev, "i82527 mode with additional functions\n");
863 } else {
864 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
865 netdev_dbg(dev, "strict i82527 compatibility mode\n");
866 }
867
868 chipset_init(priv);
869 set_reset_mode(dev);
870
871 return register_candev(dev);
872}
873EXPORT_SYMBOL_GPL(register_cc770dev);
874
875void unregister_cc770dev(struct net_device *dev)
876{
877 set_reset_mode(dev);
878 unregister_candev(dev);
879}
880EXPORT_SYMBOL_GPL(unregister_cc770dev);
881
882static __init int cc770_init(void)
883{
884 if (msgobj15_eff) {
885 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
886 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
887 }
888
889 pr_info("CAN netdevice driver\n");
890
891 return 0;
892}
893module_init(cc770_init);
894
895static __exit void cc770_exit(void)
896{
897 pr_info("driver removed\n");
898}
899module_exit(cc770_exit);
1/*
2 * Core driver for the CC770 and AN82527 CAN controllers
3 *
4 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the version 2 of the GNU General Public License
8 * as published by the Free Software Foundation
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/types.h>
23#include <linux/fcntl.h>
24#include <linux/interrupt.h>
25#include <linux/ptrace.h>
26#include <linux/string.h>
27#include <linux/errno.h>
28#include <linux/netdevice.h>
29#include <linux/if_arp.h>
30#include <linux/if_ether.h>
31#include <linux/skbuff.h>
32#include <linux/delay.h>
33
34#include <linux/can.h>
35#include <linux/can/dev.h>
36#include <linux/can/error.h>
37#include <linux/can/platform/cc770.h>
38
39#include "cc770.h"
40
41MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
42MODULE_LICENSE("GPL v2");
43MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
44
45/*
46 * The CC770 is a CAN controller from Bosch, which is 100% compatible
47 * with the AN82527 from Intel, but with "bugs" being fixed and some
48 * additional functionality, mainly:
49 *
50 * 1. RX and TX error counters are readable.
51 * 2. Support of silent (listen-only) mode.
52 * 3. Message object 15 can receive all types of frames, also RTR and EFF.
53 *
54 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
55 * which explains in detail the compatibility between the CC770 and the
56 * 82527. This driver use the additional functionality 3. on real CC770
57 * devices. Unfortunately, the CC770 does still not store the message
58 * identifier of received remote transmission request frames and
59 * therefore it's set to 0.
60 *
61 * The message objects 1..14 can be used for TX and RX while the message
62 * objects 15 is optimized for RX. It has a shadow register for reliable
63 * data reception under heavy bus load. Therefore it makes sense to use
64 * this message object for the needed use case. The frame type (EFF/SFF)
65 * for the message object 15 can be defined via kernel module parameter
66 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
67 * otherwise 11 bit SFF messages.
68 */
69static int msgobj15_eff;
70module_param(msgobj15_eff, int, 0444);
71MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
72 "(default: 11-bit standard frames)");
73
74static int i82527_compat;
75module_param(i82527_compat, int, 0444);
76MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
77 "without using additional functions");
78
79/*
80 * This driver uses the last 5 message objects 11..15. The definitions
81 * and structure below allows to configure and assign them to the real
82 * message object.
83 */
84static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
85 [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
86 [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
87 [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
88 [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
89 CC770_OBJ_FLAG_EFF,
90 [CC770_OBJ_TX] = 0,
91};
92
93static const struct can_bittiming_const cc770_bittiming_const = {
94 .name = KBUILD_MODNAME,
95 .tseg1_min = 1,
96 .tseg1_max = 16,
97 .tseg2_min = 1,
98 .tseg2_max = 8,
99 .sjw_max = 4,
100 .brp_min = 1,
101 .brp_max = 64,
102 .brp_inc = 1,
103};
104
105static inline int intid2obj(unsigned int intid)
106{
107 if (intid == 2)
108 return 0;
109 else
110 return MSGOBJ_LAST + 2 - intid;
111}
112
113static void enable_all_objs(const struct net_device *dev)
114{
115 struct cc770_priv *priv = netdev_priv(dev);
116 u8 msgcfg;
117 unsigned char obj_flags;
118 unsigned int o, mo;
119
120 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
121 obj_flags = priv->obj_flags[o];
122 mo = obj2msgobj(o);
123
124 if (obj_flags & CC770_OBJ_FLAG_RX) {
125 /*
126 * We don't need extra objects for RTR and EFF if
127 * the additional CC770 functions are enabled.
128 */
129 if (priv->control_normal_mode & CTRL_EAF) {
130 if (o > 0)
131 continue;
132 netdev_dbg(dev, "Message object %d for "
133 "RX data, RTR, SFF and EFF\n", mo);
134 } else {
135 netdev_dbg(dev,
136 "Message object %d for RX %s %s\n",
137 mo, obj_flags & CC770_OBJ_FLAG_RTR ?
138 "RTR" : "data",
139 obj_flags & CC770_OBJ_FLAG_EFF ?
140 "EFF" : "SFF");
141 }
142
143 if (obj_flags & CC770_OBJ_FLAG_EFF)
144 msgcfg = MSGCFG_XTD;
145 else
146 msgcfg = 0;
147 if (obj_flags & CC770_OBJ_FLAG_RTR)
148 msgcfg |= MSGCFG_DIR;
149
150 cc770_write_reg(priv, msgobj[mo].config, msgcfg);
151 cc770_write_reg(priv, msgobj[mo].ctrl0,
152 MSGVAL_SET | TXIE_RES |
153 RXIE_SET | INTPND_RES);
154
155 if (obj_flags & CC770_OBJ_FLAG_RTR)
156 cc770_write_reg(priv, msgobj[mo].ctrl1,
157 NEWDAT_RES | CPUUPD_SET |
158 TXRQST_RES | RMTPND_RES);
159 else
160 cc770_write_reg(priv, msgobj[mo].ctrl1,
161 NEWDAT_RES | MSGLST_RES |
162 TXRQST_RES | RMTPND_RES);
163 } else {
164 netdev_dbg(dev, "Message object %d for "
165 "TX data, RTR, SFF and EFF\n", mo);
166
167 cc770_write_reg(priv, msgobj[mo].ctrl1,
168 RMTPND_RES | TXRQST_RES |
169 CPUUPD_RES | NEWDAT_RES);
170 cc770_write_reg(priv, msgobj[mo].ctrl0,
171 MSGVAL_RES | TXIE_RES |
172 RXIE_RES | INTPND_RES);
173 }
174 }
175}
176
177static void disable_all_objs(const struct cc770_priv *priv)
178{
179 int o, mo;
180
181 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
182 mo = obj2msgobj(o);
183
184 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
185 if (o > 0 && priv->control_normal_mode & CTRL_EAF)
186 continue;
187
188 cc770_write_reg(priv, msgobj[mo].ctrl1,
189 NEWDAT_RES | MSGLST_RES |
190 TXRQST_RES | RMTPND_RES);
191 cc770_write_reg(priv, msgobj[mo].ctrl0,
192 MSGVAL_RES | TXIE_RES |
193 RXIE_RES | INTPND_RES);
194 } else {
195 /* Clear message object for send */
196 cc770_write_reg(priv, msgobj[mo].ctrl1,
197 RMTPND_RES | TXRQST_RES |
198 CPUUPD_RES | NEWDAT_RES);
199 cc770_write_reg(priv, msgobj[mo].ctrl0,
200 MSGVAL_RES | TXIE_RES |
201 RXIE_RES | INTPND_RES);
202 }
203 }
204}
205
206static void set_reset_mode(struct net_device *dev)
207{
208 struct cc770_priv *priv = netdev_priv(dev);
209
210 /* Enable configuration and puts chip in bus-off, disable interrupts */
211 cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
212
213 priv->can.state = CAN_STATE_STOPPED;
214
215 /* Clear interrupts */
216 cc770_read_reg(priv, interrupt);
217
218 /* Clear status register */
219 cc770_write_reg(priv, status, 0);
220
221 /* Disable all used message objects */
222 disable_all_objs(priv);
223}
224
225static void set_normal_mode(struct net_device *dev)
226{
227 struct cc770_priv *priv = netdev_priv(dev);
228
229 /* Clear interrupts */
230 cc770_read_reg(priv, interrupt);
231
232 /* Clear status register and pre-set last error code */
233 cc770_write_reg(priv, status, STAT_LEC_MASK);
234
235 /* Enable all used message objects*/
236 enable_all_objs(dev);
237
238 /*
239 * Clear bus-off, interrupts only for errors,
240 * not for status change
241 */
242 cc770_write_reg(priv, control, priv->control_normal_mode);
243
244 priv->can.state = CAN_STATE_ERROR_ACTIVE;
245}
246
247static void chipset_init(struct cc770_priv *priv)
248{
249 int mo, id, data;
250
251 /* Enable configuration and put chip in bus-off, disable interrupts */
252 cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
253
254 /* Set CLKOUT divider and slew rates */
255 cc770_write_reg(priv, clkout, priv->clkout);
256
257 /* Configure CPU interface / CLKOUT enable */
258 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
259
260 /* Set bus configuration */
261 cc770_write_reg(priv, bus_config, priv->bus_config);
262
263 /* Clear interrupts */
264 cc770_read_reg(priv, interrupt);
265
266 /* Clear status register */
267 cc770_write_reg(priv, status, 0);
268
269 /* Clear and invalidate message objects */
270 for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
271 cc770_write_reg(priv, msgobj[mo].ctrl0,
272 INTPND_UNC | RXIE_RES |
273 TXIE_RES | MSGVAL_RES);
274 cc770_write_reg(priv, msgobj[mo].ctrl0,
275 INTPND_RES | RXIE_RES |
276 TXIE_RES | MSGVAL_RES);
277 cc770_write_reg(priv, msgobj[mo].ctrl1,
278 NEWDAT_RES | MSGLST_RES |
279 TXRQST_RES | RMTPND_RES);
280 for (data = 0; data < 8; data++)
281 cc770_write_reg(priv, msgobj[mo].data[data], 0);
282 for (id = 0; id < 4; id++)
283 cc770_write_reg(priv, msgobj[mo].id[id], 0);
284 cc770_write_reg(priv, msgobj[mo].config, 0);
285 }
286
287 /* Set all global ID masks to "don't care" */
288 cc770_write_reg(priv, global_mask_std[0], 0);
289 cc770_write_reg(priv, global_mask_std[1], 0);
290 cc770_write_reg(priv, global_mask_ext[0], 0);
291 cc770_write_reg(priv, global_mask_ext[1], 0);
292 cc770_write_reg(priv, global_mask_ext[2], 0);
293 cc770_write_reg(priv, global_mask_ext[3], 0);
294
295}
296
297static int cc770_probe_chip(struct net_device *dev)
298{
299 struct cc770_priv *priv = netdev_priv(dev);
300
301 /* Enable configuration, put chip in bus-off, disable ints */
302 cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
303 /* Configure cpu interface / CLKOUT disable */
304 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
305
306 /*
307 * Check if hardware reset is still inactive or maybe there
308 * is no chip in this address space
309 */
310 if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
311 netdev_info(dev, "probing @0x%p failed (reset)\n",
312 priv->reg_base);
313 return -ENODEV;
314 }
315
316 /* Write and read back test pattern (some arbitrary values) */
317 cc770_write_reg(priv, msgobj[1].data[1], 0x25);
318 cc770_write_reg(priv, msgobj[2].data[3], 0x52);
319 cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
320 if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
321 (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
322 (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
323 netdev_info(dev, "probing @0x%p failed (pattern)\n",
324 priv->reg_base);
325 return -ENODEV;
326 }
327
328 /* Check if this chip is a CC770 supporting additional functions */
329 if (cc770_read_reg(priv, control) & CTRL_EAF)
330 priv->control_normal_mode |= CTRL_EAF;
331
332 return 0;
333}
334
335static void cc770_start(struct net_device *dev)
336{
337 struct cc770_priv *priv = netdev_priv(dev);
338
339 /* leave reset mode */
340 if (priv->can.state != CAN_STATE_STOPPED)
341 set_reset_mode(dev);
342
343 /* leave reset mode */
344 set_normal_mode(dev);
345}
346
347static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
348{
349 switch (mode) {
350 case CAN_MODE_START:
351 cc770_start(dev);
352 netif_wake_queue(dev);
353 break;
354
355 default:
356 return -EOPNOTSUPP;
357 }
358
359 return 0;
360}
361
362static int cc770_set_bittiming(struct net_device *dev)
363{
364 struct cc770_priv *priv = netdev_priv(dev);
365 struct can_bittiming *bt = &priv->can.bittiming;
366 u8 btr0, btr1;
367
368 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
369 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
370 (((bt->phase_seg2 - 1) & 0x7) << 4);
371 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
372 btr1 |= 0x80;
373
374 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
375
376 cc770_write_reg(priv, bit_timing_0, btr0);
377 cc770_write_reg(priv, bit_timing_1, btr1);
378
379 return 0;
380}
381
382static int cc770_get_berr_counter(const struct net_device *dev,
383 struct can_berr_counter *bec)
384{
385 struct cc770_priv *priv = netdev_priv(dev);
386
387 bec->txerr = cc770_read_reg(priv, tx_error_counter);
388 bec->rxerr = cc770_read_reg(priv, rx_error_counter);
389
390 return 0;
391}
392
393static void cc770_tx(struct net_device *dev, int mo)
394{
395 struct cc770_priv *priv = netdev_priv(dev);
396 struct can_frame *cf = (struct can_frame *)priv->tx_skb->data;
397 u8 dlc, rtr;
398 u32 id;
399 int i;
400
401 dlc = cf->can_dlc;
402 id = cf->can_id;
403 rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR;
404
405 cc770_write_reg(priv, msgobj[mo].ctrl0,
406 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
407 cc770_write_reg(priv, msgobj[mo].ctrl1,
408 RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
409
410 if (id & CAN_EFF_FLAG) {
411 id &= CAN_EFF_MASK;
412 cc770_write_reg(priv, msgobj[mo].config,
413 (dlc << 4) | rtr | MSGCFG_XTD);
414 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
415 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
416 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
417 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
418 } else {
419 id &= CAN_SFF_MASK;
420 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
421 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
422 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
423 }
424
425 for (i = 0; i < dlc; i++)
426 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
427
428 cc770_write_reg(priv, msgobj[mo].ctrl1,
429 RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
430 cc770_write_reg(priv, msgobj[mo].ctrl0,
431 MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC);
432}
433
434static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
435{
436 struct cc770_priv *priv = netdev_priv(dev);
437 unsigned int mo = obj2msgobj(CC770_OBJ_TX);
438
439 if (can_dropped_invalid_skb(dev, skb))
440 return NETDEV_TX_OK;
441
442 netif_stop_queue(dev);
443
444 if ((cc770_read_reg(priv,
445 msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
446 netdev_err(dev, "TX register is still occupied!\n");
447 return NETDEV_TX_BUSY;
448 }
449
450 priv->tx_skb = skb;
451 cc770_tx(dev, mo);
452
453 return NETDEV_TX_OK;
454}
455
456static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
457{
458 struct cc770_priv *priv = netdev_priv(dev);
459 struct net_device_stats *stats = &dev->stats;
460 struct can_frame *cf;
461 struct sk_buff *skb;
462 u8 config;
463 u32 id;
464 int i;
465
466 skb = alloc_can_skb(dev, &cf);
467 if (!skb)
468 return;
469
470 config = cc770_read_reg(priv, msgobj[mo].config);
471
472 if (ctrl1 & RMTPND_SET) {
473 /*
474 * Unfortunately, the chip does not store the real message
475 * identifier of the received remote transmission request
476 * frame. Therefore we set it to 0.
477 */
478 cf->can_id = CAN_RTR_FLAG;
479 if (config & MSGCFG_XTD)
480 cf->can_id |= CAN_EFF_FLAG;
481 cf->can_dlc = 0;
482 } else {
483 if (config & MSGCFG_XTD) {
484 id = cc770_read_reg(priv, msgobj[mo].id[3]);
485 id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
486 id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
487 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
488 id >>= 3;
489 id |= CAN_EFF_FLAG;
490 } else {
491 id = cc770_read_reg(priv, msgobj[mo].id[1]);
492 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
493 id >>= 5;
494 }
495
496 cf->can_id = id;
497 cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
498 for (i = 0; i < cf->can_dlc; i++)
499 cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
500 }
501
502 stats->rx_packets++;
503 stats->rx_bytes += cf->can_dlc;
504 netif_rx(skb);
505}
506
507static int cc770_err(struct net_device *dev, u8 status)
508{
509 struct cc770_priv *priv = netdev_priv(dev);
510 struct net_device_stats *stats = &dev->stats;
511 struct can_frame *cf;
512 struct sk_buff *skb;
513 u8 lec;
514
515 netdev_dbg(dev, "status interrupt (%#x)\n", status);
516
517 skb = alloc_can_err_skb(dev, &cf);
518 if (!skb)
519 return -ENOMEM;
520
521 /* Use extended functions of the CC770 */
522 if (priv->control_normal_mode & CTRL_EAF) {
523 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
524 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
525 }
526
527 if (status & STAT_BOFF) {
528 /* Disable interrupts */
529 cc770_write_reg(priv, control, CTRL_INI);
530 cf->can_id |= CAN_ERR_BUSOFF;
531 priv->can.state = CAN_STATE_BUS_OFF;
532 priv->can.can_stats.bus_off++;
533 can_bus_off(dev);
534 } else if (status & STAT_WARN) {
535 cf->can_id |= CAN_ERR_CRTL;
536 /* Only the CC770 does show error passive */
537 if (cf->data[7] > 127) {
538 cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
539 CAN_ERR_CRTL_TX_PASSIVE;
540 priv->can.state = CAN_STATE_ERROR_PASSIVE;
541 priv->can.can_stats.error_passive++;
542 } else {
543 cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
544 CAN_ERR_CRTL_TX_WARNING;
545 priv->can.state = CAN_STATE_ERROR_WARNING;
546 priv->can.can_stats.error_warning++;
547 }
548 } else {
549 /* Back to error avtive */
550 cf->can_id |= CAN_ERR_PROT;
551 cf->data[2] = CAN_ERR_PROT_ACTIVE;
552 priv->can.state = CAN_STATE_ERROR_ACTIVE;
553 }
554
555 lec = status & STAT_LEC_MASK;
556 if (lec < 7 && lec > 0) {
557 if (lec == STAT_LEC_ACK) {
558 cf->can_id |= CAN_ERR_ACK;
559 } else {
560 cf->can_id |= CAN_ERR_PROT;
561 switch (lec) {
562 case STAT_LEC_STUFF:
563 cf->data[2] |= CAN_ERR_PROT_STUFF;
564 break;
565 case STAT_LEC_FORM:
566 cf->data[2] |= CAN_ERR_PROT_FORM;
567 break;
568 case STAT_LEC_BIT1:
569 cf->data[2] |= CAN_ERR_PROT_BIT1;
570 break;
571 case STAT_LEC_BIT0:
572 cf->data[2] |= CAN_ERR_PROT_BIT0;
573 break;
574 case STAT_LEC_CRC:
575 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
576 break;
577 }
578 }
579 }
580
581
582 stats->rx_packets++;
583 stats->rx_bytes += cf->can_dlc;
584 netif_rx(skb);
585
586 return 0;
587}
588
589static int cc770_status_interrupt(struct net_device *dev)
590{
591 struct cc770_priv *priv = netdev_priv(dev);
592 u8 status;
593
594 status = cc770_read_reg(priv, status);
595 /* Reset the status register including RXOK and TXOK */
596 cc770_write_reg(priv, status, STAT_LEC_MASK);
597
598 if (status & (STAT_WARN | STAT_BOFF) ||
599 (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
600 cc770_err(dev, status);
601 return status & STAT_BOFF;
602 }
603
604 return 0;
605}
606
607static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
608{
609 struct cc770_priv *priv = netdev_priv(dev);
610 struct net_device_stats *stats = &dev->stats;
611 unsigned int mo = obj2msgobj(o);
612 u8 ctrl1;
613 int n = CC770_MAX_MSG;
614
615 while (n--) {
616 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
617
618 if (!(ctrl1 & NEWDAT_SET)) {
619 /* Check for RTR if additional functions are enabled */
620 if (priv->control_normal_mode & CTRL_EAF) {
621 if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
622 INTPND_SET))
623 break;
624 } else {
625 break;
626 }
627 }
628
629 if (ctrl1 & MSGLST_SET) {
630 stats->rx_over_errors++;
631 stats->rx_errors++;
632 }
633 if (mo < MSGOBJ_LAST)
634 cc770_write_reg(priv, msgobj[mo].ctrl1,
635 NEWDAT_RES | MSGLST_RES |
636 TXRQST_UNC | RMTPND_UNC);
637 cc770_rx(dev, mo, ctrl1);
638
639 cc770_write_reg(priv, msgobj[mo].ctrl0,
640 MSGVAL_SET | TXIE_RES |
641 RXIE_SET | INTPND_RES);
642 cc770_write_reg(priv, msgobj[mo].ctrl1,
643 NEWDAT_RES | MSGLST_RES |
644 TXRQST_RES | RMTPND_RES);
645 }
646}
647
648static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
649{
650 struct cc770_priv *priv = netdev_priv(dev);
651 unsigned int mo = obj2msgobj(o);
652 u8 ctrl0, ctrl1;
653 int n = CC770_MAX_MSG;
654
655 while (n--) {
656 ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
657 if (!(ctrl0 & INTPND_SET))
658 break;
659
660 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
661 cc770_rx(dev, mo, ctrl1);
662
663 cc770_write_reg(priv, msgobj[mo].ctrl0,
664 MSGVAL_SET | TXIE_RES |
665 RXIE_SET | INTPND_RES);
666 cc770_write_reg(priv, msgobj[mo].ctrl1,
667 NEWDAT_RES | CPUUPD_SET |
668 TXRQST_RES | RMTPND_RES);
669 }
670}
671
672static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
673{
674 struct cc770_priv *priv = netdev_priv(dev);
675 struct net_device_stats *stats = &dev->stats;
676 unsigned int mo = obj2msgobj(o);
677 struct can_frame *cf;
678 u8 ctrl1;
679
680 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
681
682 cc770_write_reg(priv, msgobj[mo].ctrl0,
683 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
684 cc770_write_reg(priv, msgobj[mo].ctrl1,
685 RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES);
686
687 if (unlikely(!priv->tx_skb)) {
688 netdev_err(dev, "missing tx skb in tx interrupt\n");
689 return;
690 }
691
692 if (unlikely(ctrl1 & MSGLST_SET)) {
693 stats->rx_over_errors++;
694 stats->rx_errors++;
695 }
696
697 /* When the CC770 is sending an RTR message and it receives a regular
698 * message that matches the id of the RTR message, it will overwrite the
699 * outgoing message in the TX register. When this happens we must
700 * process the received message and try to transmit the outgoing skb
701 * again.
702 */
703 if (unlikely(ctrl1 & NEWDAT_SET)) {
704 cc770_rx(dev, mo, ctrl1);
705 cc770_tx(dev, mo);
706 return;
707 }
708
709 cf = (struct can_frame *)priv->tx_skb->data;
710 stats->tx_bytes += cf->can_dlc;
711 stats->tx_packets++;
712
713 can_put_echo_skb(priv->tx_skb, dev, 0);
714 can_get_echo_skb(dev, 0);
715 priv->tx_skb = NULL;
716
717 netif_wake_queue(dev);
718}
719
720static irqreturn_t cc770_interrupt(int irq, void *dev_id)
721{
722 struct net_device *dev = (struct net_device *)dev_id;
723 struct cc770_priv *priv = netdev_priv(dev);
724 u8 intid;
725 int o, n = 0;
726
727 /* Shared interrupts and IRQ off? */
728 if (priv->can.state == CAN_STATE_STOPPED)
729 return IRQ_NONE;
730
731 if (priv->pre_irq)
732 priv->pre_irq(priv);
733
734 while (n < CC770_MAX_IRQ) {
735 /* Read the highest pending interrupt request */
736 intid = cc770_read_reg(priv, interrupt);
737 if (!intid)
738 break;
739 n++;
740
741 if (intid == 1) {
742 /* Exit in case of bus-off */
743 if (cc770_status_interrupt(dev))
744 break;
745 } else {
746 o = intid2obj(intid);
747
748 if (o >= CC770_OBJ_MAX) {
749 netdev_err(dev, "Unexpected interrupt id %d\n",
750 intid);
751 continue;
752 }
753
754 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
755 cc770_rtr_interrupt(dev, o);
756 else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
757 cc770_rx_interrupt(dev, o);
758 else
759 cc770_tx_interrupt(dev, o);
760 }
761 }
762
763 if (priv->post_irq)
764 priv->post_irq(priv);
765
766 if (n >= CC770_MAX_IRQ)
767 netdev_dbg(dev, "%d messages handled in ISR", n);
768
769 return (n) ? IRQ_HANDLED : IRQ_NONE;
770}
771
772static int cc770_open(struct net_device *dev)
773{
774 struct cc770_priv *priv = netdev_priv(dev);
775 int err;
776
777 /* set chip into reset mode */
778 set_reset_mode(dev);
779
780 /* common open */
781 err = open_candev(dev);
782 if (err)
783 return err;
784
785 err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
786 dev->name, dev);
787 if (err) {
788 close_candev(dev);
789 return -EAGAIN;
790 }
791
792 /* init and start chip */
793 cc770_start(dev);
794
795 netif_start_queue(dev);
796
797 return 0;
798}
799
800static int cc770_close(struct net_device *dev)
801{
802 netif_stop_queue(dev);
803 set_reset_mode(dev);
804
805 free_irq(dev->irq, dev);
806 close_candev(dev);
807
808 return 0;
809}
810
811struct net_device *alloc_cc770dev(int sizeof_priv)
812{
813 struct net_device *dev;
814 struct cc770_priv *priv;
815
816 dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
817 CC770_ECHO_SKB_MAX);
818 if (!dev)
819 return NULL;
820
821 priv = netdev_priv(dev);
822
823 priv->dev = dev;
824 priv->can.bittiming_const = &cc770_bittiming_const;
825 priv->can.do_set_bittiming = cc770_set_bittiming;
826 priv->can.do_set_mode = cc770_set_mode;
827 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
828 priv->tx_skb = NULL;
829
830 memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
831
832 if (sizeof_priv)
833 priv->priv = (void *)priv + sizeof(struct cc770_priv);
834
835 return dev;
836}
837EXPORT_SYMBOL_GPL(alloc_cc770dev);
838
839void free_cc770dev(struct net_device *dev)
840{
841 free_candev(dev);
842}
843EXPORT_SYMBOL_GPL(free_cc770dev);
844
845static const struct net_device_ops cc770_netdev_ops = {
846 .ndo_open = cc770_open,
847 .ndo_stop = cc770_close,
848 .ndo_start_xmit = cc770_start_xmit,
849 .ndo_change_mtu = can_change_mtu,
850};
851
852int register_cc770dev(struct net_device *dev)
853{
854 struct cc770_priv *priv = netdev_priv(dev);
855 int err;
856
857 err = cc770_probe_chip(dev);
858 if (err)
859 return err;
860
861 dev->netdev_ops = &cc770_netdev_ops;
862
863 dev->flags |= IFF_ECHO; /* we support local echo */
864
865 /* Should we use additional functions? */
866 if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
867 priv->can.do_get_berr_counter = cc770_get_berr_counter;
868 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
869 netdev_dbg(dev, "i82527 mode with additional functions\n");
870 } else {
871 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
872 netdev_dbg(dev, "strict i82527 compatibility mode\n");
873 }
874
875 chipset_init(priv);
876 set_reset_mode(dev);
877
878 return register_candev(dev);
879}
880EXPORT_SYMBOL_GPL(register_cc770dev);
881
882void unregister_cc770dev(struct net_device *dev)
883{
884 set_reset_mode(dev);
885 unregister_candev(dev);
886}
887EXPORT_SYMBOL_GPL(unregister_cc770dev);
888
889static __init int cc770_init(void)
890{
891 if (msgobj15_eff) {
892 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
893 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
894 }
895
896 pr_info("CAN netdevice driver\n");
897
898 return 0;
899}
900module_init(cc770_init);
901
902static __exit void cc770_exit(void)
903{
904 pr_info("driver removed\n");
905}
906module_exit(cc770_exit);