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
41 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
42 MODULE_LICENSE("GPL v2");
43 MODULE_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 receiption 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 */
69 static int msgobj15_eff;
70 module_param(msgobj15_eff, int, S_IRUGO);
71 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
72 "(default: 11-bit standard frames)");
73
74 static int i82527_compat;
75 module_param(i82527_compat, int, S_IRUGO);
76 MODULE_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 */
84 static 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
93 static 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
intid2obj(unsigned int intid)105 static inline int intid2obj(unsigned int intid)
106 {
107 if (intid == 2)
108 return 0;
109 else
110 return MSGOBJ_LAST + 2 - intid;
111 }
112
enable_all_objs(const struct net_device * dev)113 static 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
disable_all_objs(const struct cc770_priv * priv)177 static 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
set_reset_mode(struct net_device * dev)206 static 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
set_normal_mode(struct net_device * dev)225 static 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
chipset_init(struct cc770_priv * priv)247 static 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
cc770_probe_chip(struct net_device * dev)297 static 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
cc770_start(struct net_device * dev)335 static 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
cc770_set_mode(struct net_device * dev,enum can_mode mode)347 static 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
cc770_set_bittiming(struct net_device * dev)362 static 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
cc770_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)382 static 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
cc770_start_xmit(struct sk_buff * skb,struct net_device * dev)393 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
394 {
395 struct cc770_priv *priv = netdev_priv(dev);
396 struct net_device_stats *stats = &dev->stats;
397 struct can_frame *cf = (struct can_frame *)skb->data;
398 unsigned int mo = obj2msgobj(CC770_OBJ_TX);
399 u8 dlc, rtr;
400 u32 id;
401 int i;
402
403 if (can_dropped_invalid_skb(dev, skb))
404 return NETDEV_TX_OK;
405
406 if ((cc770_read_reg(priv,
407 msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
408 netdev_err(dev, "TX register is still occupied!\n");
409 return NETDEV_TX_BUSY;
410 }
411
412 netif_stop_queue(dev);
413
414 dlc = cf->can_dlc;
415 id = cf->can_id;
416 if (cf->can_id & CAN_RTR_FLAG)
417 rtr = 0;
418 else
419 rtr = MSGCFG_DIR;
420 cc770_write_reg(priv, msgobj[mo].ctrl1,
421 RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
422 cc770_write_reg(priv, msgobj[mo].ctrl0,
423 MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
424 if (id & CAN_EFF_FLAG) {
425 id &= CAN_EFF_MASK;
426 cc770_write_reg(priv, msgobj[mo].config,
427 (dlc << 4) | rtr | MSGCFG_XTD);
428 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
429 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
430 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
431 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
432 } else {
433 id &= CAN_SFF_MASK;
434 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
435 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
436 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
437 }
438
439 for (i = 0; i < dlc; i++)
440 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
441
442 /* Store echo skb before starting the transfer */
443 can_put_echo_skb(skb, dev, 0);
444
445 cc770_write_reg(priv, msgobj[mo].ctrl1,
446 RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
447
448 stats->tx_bytes += dlc;
449
450
451 /*
452 * HM: We had some cases of repeated IRQs so make sure the
453 * INT is acknowledged I know it's already further up, but
454 * doing again fixed the issue
455 */
456 cc770_write_reg(priv, msgobj[mo].ctrl0,
457 MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
458
459 return NETDEV_TX_OK;
460 }
461
cc770_rx(struct net_device * dev,unsigned int mo,u8 ctrl1)462 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
463 {
464 struct cc770_priv *priv = netdev_priv(dev);
465 struct net_device_stats *stats = &dev->stats;
466 struct can_frame *cf;
467 struct sk_buff *skb;
468 u8 config;
469 u32 id;
470 int i;
471
472 skb = alloc_can_skb(dev, &cf);
473 if (!skb)
474 return;
475
476 config = cc770_read_reg(priv, msgobj[mo].config);
477
478 if (ctrl1 & RMTPND_SET) {
479 /*
480 * Unfortunately, the chip does not store the real message
481 * identifier of the received remote transmission request
482 * frame. Therefore we set it to 0.
483 */
484 cf->can_id = CAN_RTR_FLAG;
485 if (config & MSGCFG_XTD)
486 cf->can_id |= CAN_EFF_FLAG;
487 cf->can_dlc = 0;
488 } else {
489 if (config & MSGCFG_XTD) {
490 id = cc770_read_reg(priv, msgobj[mo].id[3]);
491 id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
492 id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
493 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
494 id >>= 3;
495 id |= CAN_EFF_FLAG;
496 } else {
497 id = cc770_read_reg(priv, msgobj[mo].id[1]);
498 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
499 id >>= 5;
500 }
501
502 cf->can_id = id;
503 cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
504 for (i = 0; i < cf->can_dlc; i++)
505 cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
506 }
507 netif_rx(skb);
508
509 stats->rx_packets++;
510 stats->rx_bytes += cf->can_dlc;
511 }
512
cc770_err(struct net_device * dev,u8 status)513 static int cc770_err(struct net_device *dev, u8 status)
514 {
515 struct cc770_priv *priv = netdev_priv(dev);
516 struct net_device_stats *stats = &dev->stats;
517 struct can_frame *cf;
518 struct sk_buff *skb;
519 u8 lec;
520
521 netdev_dbg(dev, "status interrupt (%#x)\n", status);
522
523 skb = alloc_can_err_skb(dev, &cf);
524 if (!skb)
525 return -ENOMEM;
526
527 /* Use extended functions of the CC770 */
528 if (priv->control_normal_mode & CTRL_EAF) {
529 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
530 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
531 }
532
533 if (status & STAT_BOFF) {
534 /* Disable interrupts */
535 cc770_write_reg(priv, control, CTRL_INI);
536 cf->can_id |= CAN_ERR_BUSOFF;
537 priv->can.state = CAN_STATE_BUS_OFF;
538 can_bus_off(dev);
539 } else if (status & STAT_WARN) {
540 cf->can_id |= CAN_ERR_CRTL;
541 /* Only the CC770 does show error passive */
542 if (cf->data[7] > 127) {
543 cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
544 CAN_ERR_CRTL_TX_PASSIVE;
545 priv->can.state = CAN_STATE_ERROR_PASSIVE;
546 priv->can.can_stats.error_passive++;
547 } else {
548 cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
549 CAN_ERR_CRTL_TX_WARNING;
550 priv->can.state = CAN_STATE_ERROR_WARNING;
551 priv->can.can_stats.error_warning++;
552 }
553 } else {
554 /* Back to error avtive */
555 cf->can_id |= CAN_ERR_PROT;
556 cf->data[2] = CAN_ERR_PROT_ACTIVE;
557 priv->can.state = CAN_STATE_ERROR_ACTIVE;
558 }
559
560 lec = status & STAT_LEC_MASK;
561 if (lec < 7 && lec > 0) {
562 if (lec == STAT_LEC_ACK) {
563 cf->can_id |= CAN_ERR_ACK;
564 } else {
565 cf->can_id |= CAN_ERR_PROT;
566 switch (lec) {
567 case STAT_LEC_STUFF:
568 cf->data[2] |= CAN_ERR_PROT_STUFF;
569 break;
570 case STAT_LEC_FORM:
571 cf->data[2] |= CAN_ERR_PROT_FORM;
572 break;
573 case STAT_LEC_BIT1:
574 cf->data[2] |= CAN_ERR_PROT_BIT1;
575 break;
576 case STAT_LEC_BIT0:
577 cf->data[2] |= CAN_ERR_PROT_BIT0;
578 break;
579 case STAT_LEC_CRC:
580 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
581 break;
582 }
583 }
584 }
585
586 netif_rx(skb);
587
588 stats->rx_packets++;
589 stats->rx_bytes += cf->can_dlc;
590
591 return 0;
592 }
593
cc770_status_interrupt(struct net_device * dev)594 static int cc770_status_interrupt(struct net_device *dev)
595 {
596 struct cc770_priv *priv = netdev_priv(dev);
597 u8 status;
598
599 status = cc770_read_reg(priv, status);
600 /* Reset the status register including RXOK and TXOK */
601 cc770_write_reg(priv, status, STAT_LEC_MASK);
602
603 if (status & (STAT_WARN | STAT_BOFF) ||
604 (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
605 cc770_err(dev, status);
606 return status & STAT_BOFF;
607 }
608
609 return 0;
610 }
611
cc770_rx_interrupt(struct net_device * dev,unsigned int o)612 static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
613 {
614 struct cc770_priv *priv = netdev_priv(dev);
615 struct net_device_stats *stats = &dev->stats;
616 unsigned int mo = obj2msgobj(o);
617 u8 ctrl1;
618 int n = CC770_MAX_MSG;
619
620 while (n--) {
621 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
622
623 if (!(ctrl1 & NEWDAT_SET)) {
624 /* Check for RTR if additional functions are enabled */
625 if (priv->control_normal_mode & CTRL_EAF) {
626 if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
627 INTPND_SET))
628 break;
629 } else {
630 break;
631 }
632 }
633
634 if (ctrl1 & MSGLST_SET) {
635 stats->rx_over_errors++;
636 stats->rx_errors++;
637 }
638 if (mo < MSGOBJ_LAST)
639 cc770_write_reg(priv, msgobj[mo].ctrl1,
640 NEWDAT_RES | MSGLST_RES |
641 TXRQST_UNC | RMTPND_UNC);
642 cc770_rx(dev, mo, ctrl1);
643
644 cc770_write_reg(priv, msgobj[mo].ctrl0,
645 MSGVAL_SET | TXIE_RES |
646 RXIE_SET | INTPND_RES);
647 cc770_write_reg(priv, msgobj[mo].ctrl1,
648 NEWDAT_RES | MSGLST_RES |
649 TXRQST_RES | RMTPND_RES);
650 }
651 }
652
cc770_rtr_interrupt(struct net_device * dev,unsigned int o)653 static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
654 {
655 struct cc770_priv *priv = netdev_priv(dev);
656 unsigned int mo = obj2msgobj(o);
657 u8 ctrl0, ctrl1;
658 int n = CC770_MAX_MSG;
659
660 while (n--) {
661 ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
662 if (!(ctrl0 & INTPND_SET))
663 break;
664
665 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
666 cc770_rx(dev, mo, ctrl1);
667
668 cc770_write_reg(priv, msgobj[mo].ctrl0,
669 MSGVAL_SET | TXIE_RES |
670 RXIE_SET | INTPND_RES);
671 cc770_write_reg(priv, msgobj[mo].ctrl1,
672 NEWDAT_RES | CPUUPD_SET |
673 TXRQST_RES | RMTPND_RES);
674 }
675 }
676
cc770_tx_interrupt(struct net_device * dev,unsigned int o)677 static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
678 {
679 struct cc770_priv *priv = netdev_priv(dev);
680 struct net_device_stats *stats = &dev->stats;
681 unsigned int mo = obj2msgobj(o);
682
683 /* Nothing more to send, switch off interrupts */
684 cc770_write_reg(priv, msgobj[mo].ctrl0,
685 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
686 /*
687 * We had some cases of repeated IRQ so make sure the
688 * INT is acknowledged
689 */
690 cc770_write_reg(priv, msgobj[mo].ctrl0,
691 MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
692
693 stats->tx_packets++;
694 can_get_echo_skb(dev, 0);
695 netif_wake_queue(dev);
696 }
697
cc770_interrupt(int irq,void * dev_id)698 irqreturn_t cc770_interrupt(int irq, void *dev_id)
699 {
700 struct net_device *dev = (struct net_device *)dev_id;
701 struct cc770_priv *priv = netdev_priv(dev);
702 u8 intid;
703 int o, n = 0;
704
705 /* Shared interrupts and IRQ off? */
706 if (priv->can.state == CAN_STATE_STOPPED)
707 return IRQ_NONE;
708
709 if (priv->pre_irq)
710 priv->pre_irq(priv);
711
712 while (n < CC770_MAX_IRQ) {
713 /* Read the highest pending interrupt request */
714 intid = cc770_read_reg(priv, interrupt);
715 if (!intid)
716 break;
717 n++;
718
719 if (intid == 1) {
720 /* Exit in case of bus-off */
721 if (cc770_status_interrupt(dev))
722 break;
723 } else {
724 o = intid2obj(intid);
725
726 if (o >= CC770_OBJ_MAX) {
727 netdev_err(dev, "Unexpected interrupt id %d\n",
728 intid);
729 continue;
730 }
731
732 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
733 cc770_rtr_interrupt(dev, o);
734 else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
735 cc770_rx_interrupt(dev, o);
736 else
737 cc770_tx_interrupt(dev, o);
738 }
739 }
740
741 if (priv->post_irq)
742 priv->post_irq(priv);
743
744 if (n >= CC770_MAX_IRQ)
745 netdev_dbg(dev, "%d messages handled in ISR", n);
746
747 return (n) ? IRQ_HANDLED : IRQ_NONE;
748 }
749
cc770_open(struct net_device * dev)750 static int cc770_open(struct net_device *dev)
751 {
752 struct cc770_priv *priv = netdev_priv(dev);
753 int err;
754
755 /* set chip into reset mode */
756 set_reset_mode(dev);
757
758 /* common open */
759 err = open_candev(dev);
760 if (err)
761 return err;
762
763 err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
764 dev->name, dev);
765 if (err) {
766 close_candev(dev);
767 return -EAGAIN;
768 }
769
770 /* init and start chip */
771 cc770_start(dev);
772
773 netif_start_queue(dev);
774
775 return 0;
776 }
777
cc770_close(struct net_device * dev)778 static int cc770_close(struct net_device *dev)
779 {
780 netif_stop_queue(dev);
781 set_reset_mode(dev);
782
783 free_irq(dev->irq, dev);
784 close_candev(dev);
785
786 return 0;
787 }
788
alloc_cc770dev(int sizeof_priv)789 struct net_device *alloc_cc770dev(int sizeof_priv)
790 {
791 struct net_device *dev;
792 struct cc770_priv *priv;
793
794 dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
795 CC770_ECHO_SKB_MAX);
796 if (!dev)
797 return NULL;
798
799 priv = netdev_priv(dev);
800
801 priv->dev = dev;
802 priv->can.bittiming_const = &cc770_bittiming_const;
803 priv->can.do_set_bittiming = cc770_set_bittiming;
804 priv->can.do_set_mode = cc770_set_mode;
805 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
806
807 memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
808
809 if (sizeof_priv)
810 priv->priv = (void *)priv + sizeof(struct cc770_priv);
811
812 return dev;
813 }
814 EXPORT_SYMBOL_GPL(alloc_cc770dev);
815
free_cc770dev(struct net_device * dev)816 void free_cc770dev(struct net_device *dev)
817 {
818 free_candev(dev);
819 }
820 EXPORT_SYMBOL_GPL(free_cc770dev);
821
822 static const struct net_device_ops cc770_netdev_ops = {
823 .ndo_open = cc770_open,
824 .ndo_stop = cc770_close,
825 .ndo_start_xmit = cc770_start_xmit,
826 };
827
register_cc770dev(struct net_device * dev)828 int register_cc770dev(struct net_device *dev)
829 {
830 struct cc770_priv *priv = netdev_priv(dev);
831 int err;
832
833 err = cc770_probe_chip(dev);
834 if (err)
835 return err;
836
837 dev->netdev_ops = &cc770_netdev_ops;
838
839 dev->flags |= IFF_ECHO; /* we support local echo */
840
841 /* Should we use additional functions? */
842 if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
843 priv->can.do_get_berr_counter = cc770_get_berr_counter;
844 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
845 netdev_dbg(dev, "i82527 mode with additional functions\n");
846 } else {
847 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
848 netdev_dbg(dev, "strict i82527 compatibility mode\n");
849 }
850
851 chipset_init(priv);
852 set_reset_mode(dev);
853
854 return register_candev(dev);
855 }
856 EXPORT_SYMBOL_GPL(register_cc770dev);
857
unregister_cc770dev(struct net_device * dev)858 void unregister_cc770dev(struct net_device *dev)
859 {
860 set_reset_mode(dev);
861 unregister_candev(dev);
862 }
863 EXPORT_SYMBOL_GPL(unregister_cc770dev);
864
cc770_init(void)865 static __init int cc770_init(void)
866 {
867 if (msgobj15_eff) {
868 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
869 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
870 }
871
872 pr_info("CAN netdevice driver\n");
873
874 return 0;
875 }
876 module_init(cc770_init);
877
cc770_exit(void)878 static __exit void cc770_exit(void)
879 {
880 pr_info("driver removed\n");
881 }
882 module_exit(cc770_exit);
883