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WIP FPC-III support
[linux/fpc-iii.git] / drivers / net / can / cc770 / cc770.c
blob8d9f332c35e0c52a552b24116dd5a3f26ecb479d
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/netdevice.h>
21 #include <linux/if_arp.h>
22 #include <linux/if_ether.h>
23 #include <linux/skbuff.h>
24 #include <linux/delay.h>
25
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29 #include <linux/can/platform/cc770.h>
30
31 #include "cc770.h"
32
33 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
34 MODULE_LICENSE("GPL v2");
35 MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
36
37 /*
38 * The CC770 is a CAN controller from Bosch, which is 100% compatible
39 * with the AN82527 from Intel, but with "bugs" being fixed and some
40 * additional functionality, mainly:
41 *
42 * 1. RX and TX error counters are readable.
43 * 2. Support of silent (listen-only) mode.
44 * 3. Message object 15 can receive all types of frames, also RTR and EFF.
45 *
46 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
47 * which explains in detail the compatibility between the CC770 and the
48 * 82527. This driver use the additional functionality 3. on real CC770
49 * devices. Unfortunately, the CC770 does still not store the message
50 * identifier of received remote transmission request frames and
51 * therefore it's set to 0.
52 *
53 * The message objects 1..14 can be used for TX and RX while the message
54 * objects 15 is optimized for RX. It has a shadow register for reliable
55 * data reception under heavy bus load. Therefore it makes sense to use
56 * this message object for the needed use case. The frame type (EFF/SFF)
57 * for the message object 15 can be defined via kernel module parameter
58 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
59 * otherwise 11 bit SFF messages.
60 */
61 static int msgobj15_eff;
62 module_param(msgobj15_eff, int, 0444);
63 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
64 "(default: 11-bit standard frames)");
65
66 static int i82527_compat;
67 module_param(i82527_compat, int, 0444);
68 MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 compatibility mode "
69 "without using additional functions");
70
71 /*
72 * This driver uses the last 5 message objects 11..15. The definitions
73 * and structure below allows to configure and assign them to the real
74 * message object.
75 */
76 static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
77 [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
78 [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
79 [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
80 [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
81 CC770_OBJ_FLAG_EFF,
82 [CC770_OBJ_TX] = 0,
83 };
84
85 static const struct can_bittiming_const cc770_bittiming_const = {
86 .name = KBUILD_MODNAME,
87 .tseg1_min = 1,
88 .tseg1_max = 16,
89 .tseg2_min = 1,
90 .tseg2_max = 8,
91 .sjw_max = 4,
92 .brp_min = 1,
93 .brp_max = 64,
94 .brp_inc = 1,
95 };
96
97 static inline int intid2obj(unsigned int intid)
98 {
99 if (intid == 2)
100 return 0;
101 else
102 return MSGOBJ_LAST + 2 - intid;
103 }
104
105 static void enable_all_objs(const struct net_device *dev)
106 {
107 struct cc770_priv *priv = netdev_priv(dev);
108 u8 msgcfg;
109 unsigned char obj_flags;
110 unsigned int o, mo;
111
112 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
113 obj_flags = priv->obj_flags[o];
114 mo = obj2msgobj(o);
115
116 if (obj_flags & CC770_OBJ_FLAG_RX) {
117 /*
118 * We don't need extra objects for RTR and EFF if
119 * the additional CC770 functions are enabled.
120 */
121 if (priv->control_normal_mode & CTRL_EAF) {
122 if (o > 0)
123 continue;
124 netdev_dbg(dev, "Message object %d for "
125 "RX data, RTR, SFF and EFF\n", mo);
126 } else {
127 netdev_dbg(dev,
128 "Message object %d for RX %s %s\n",
129 mo, obj_flags & CC770_OBJ_FLAG_RTR ?
130 "RTR" : "data",
131 obj_flags & CC770_OBJ_FLAG_EFF ?
132 "EFF" : "SFF");
133 }
134
135 if (obj_flags & CC770_OBJ_FLAG_EFF)
136 msgcfg = MSGCFG_XTD;
137 else
138 msgcfg = 0;
139 if (obj_flags & CC770_OBJ_FLAG_RTR)
140 msgcfg |= MSGCFG_DIR;
141
142 cc770_write_reg(priv, msgobj[mo].config, msgcfg);
143 cc770_write_reg(priv, msgobj[mo].ctrl0,
144 MSGVAL_SET | TXIE_RES |
145 RXIE_SET | INTPND_RES);
146
147 if (obj_flags & CC770_OBJ_FLAG_RTR)
148 cc770_write_reg(priv, msgobj[mo].ctrl1,
149 NEWDAT_RES | CPUUPD_SET |
150 TXRQST_RES | RMTPND_RES);
151 else
152 cc770_write_reg(priv, msgobj[mo].ctrl1,
153 NEWDAT_RES | MSGLST_RES |
154 TXRQST_RES | RMTPND_RES);
155 } else {
156 netdev_dbg(dev, "Message object %d for "
157 "TX data, RTR, SFF and EFF\n", mo);
158
159 cc770_write_reg(priv, msgobj[mo].ctrl1,
160 RMTPND_RES | TXRQST_RES |
161 CPUUPD_RES | NEWDAT_RES);
162 cc770_write_reg(priv, msgobj[mo].ctrl0,
163 MSGVAL_RES | TXIE_RES |
164 RXIE_RES | INTPND_RES);
165 }
166 }
167 }
168
169 static void disable_all_objs(const struct cc770_priv *priv)
170 {
171 int o, mo;
172
173 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
174 mo = obj2msgobj(o);
175
176 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
177 if (o > 0 && priv->control_normal_mode & CTRL_EAF)
178 continue;
179
180 cc770_write_reg(priv, msgobj[mo].ctrl1,
181 NEWDAT_RES | MSGLST_RES |
182 TXRQST_RES | RMTPND_RES);
183 cc770_write_reg(priv, msgobj[mo].ctrl0,
184 MSGVAL_RES | TXIE_RES |
185 RXIE_RES | INTPND_RES);
186 } else {
187 /* Clear message object for send */
188 cc770_write_reg(priv, msgobj[mo].ctrl1,
189 RMTPND_RES | TXRQST_RES |
190 CPUUPD_RES | NEWDAT_RES);
191 cc770_write_reg(priv, msgobj[mo].ctrl0,
192 MSGVAL_RES | TXIE_RES |
193 RXIE_RES | INTPND_RES);
194 }
195 }
196 }
197
198 static void set_reset_mode(struct net_device *dev)
199 {
200 struct cc770_priv *priv = netdev_priv(dev);
201
202 /* Enable configuration and puts chip in bus-off, disable interrupts */
203 cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
204
205 priv->can.state = CAN_STATE_STOPPED;
206
207 /* Clear interrupts */
208 cc770_read_reg(priv, interrupt);
209
210 /* Clear status register */
211 cc770_write_reg(priv, status, 0);
212
213 /* Disable all used message objects */
214 disable_all_objs(priv);
215 }
216
217 static void set_normal_mode(struct net_device *dev)
218 {
219 struct cc770_priv *priv = netdev_priv(dev);
220
221 /* Clear interrupts */
222 cc770_read_reg(priv, interrupt);
223
224 /* Clear status register and pre-set last error code */
225 cc770_write_reg(priv, status, STAT_LEC_MASK);
226
227 /* Enable all used message objects*/
228 enable_all_objs(dev);
229
230 /*
231 * Clear bus-off, interrupts only for errors,
232 * not for status change
233 */
234 cc770_write_reg(priv, control, priv->control_normal_mode);
235
236 priv->can.state = CAN_STATE_ERROR_ACTIVE;
237 }
238
239 static void chipset_init(struct cc770_priv *priv)
240 {
241 int mo, id, data;
242
243 /* Enable configuration and put chip in bus-off, disable interrupts */
244 cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
245
246 /* Set CLKOUT divider and slew rates */
247 cc770_write_reg(priv, clkout, priv->clkout);
248
249 /* Configure CPU interface / CLKOUT enable */
250 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
251
252 /* Set bus configuration */
253 cc770_write_reg(priv, bus_config, priv->bus_config);
254
255 /* Clear interrupts */
256 cc770_read_reg(priv, interrupt);
257
258 /* Clear status register */
259 cc770_write_reg(priv, status, 0);
260
261 /* Clear and invalidate message objects */
262 for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
263 cc770_write_reg(priv, msgobj[mo].ctrl0,
264 INTPND_UNC | RXIE_RES |
265 TXIE_RES | MSGVAL_RES);
266 cc770_write_reg(priv, msgobj[mo].ctrl0,
267 INTPND_RES | RXIE_RES |
268 TXIE_RES | MSGVAL_RES);
269 cc770_write_reg(priv, msgobj[mo].ctrl1,
270 NEWDAT_RES | MSGLST_RES |
271 TXRQST_RES | RMTPND_RES);
272 for (data = 0; data < 8; data++)
273 cc770_write_reg(priv, msgobj[mo].data[data], 0);
274 for (id = 0; id < 4; id++)
275 cc770_write_reg(priv, msgobj[mo].id[id], 0);
276 cc770_write_reg(priv, msgobj[mo].config, 0);
277 }
278
279 /* Set all global ID masks to "don't care" */
280 cc770_write_reg(priv, global_mask_std[0], 0);
281 cc770_write_reg(priv, global_mask_std[1], 0);
282 cc770_write_reg(priv, global_mask_ext[0], 0);
283 cc770_write_reg(priv, global_mask_ext[1], 0);
284 cc770_write_reg(priv, global_mask_ext[2], 0);
285 cc770_write_reg(priv, global_mask_ext[3], 0);
286
287 }
288
289 static int cc770_probe_chip(struct net_device *dev)
290 {
291 struct cc770_priv *priv = netdev_priv(dev);
292
293 /* Enable configuration, put chip in bus-off, disable ints */
294 cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
295 /* Configure cpu interface / CLKOUT disable */
296 cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
297
298 /*
299 * Check if hardware reset is still inactive or maybe there
300 * is no chip in this address space
301 */
302 if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
303 netdev_info(dev, "probing @0x%p failed (reset)\n",
304 priv->reg_base);
305 return -ENODEV;
306 }
307
308 /* Write and read back test pattern (some arbitrary values) */
309 cc770_write_reg(priv, msgobj[1].data[1], 0x25);
310 cc770_write_reg(priv, msgobj[2].data[3], 0x52);
311 cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
312 if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
313 (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
314 (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
315 netdev_info(dev, "probing @0x%p failed (pattern)\n",
316 priv->reg_base);
317 return -ENODEV;
318 }
319
320 /* Check if this chip is a CC770 supporting additional functions */
321 if (cc770_read_reg(priv, control) & CTRL_EAF)
322 priv->control_normal_mode |= CTRL_EAF;
323
324 return 0;
325 }
326
327 static void cc770_start(struct net_device *dev)
328 {
329 struct cc770_priv *priv = netdev_priv(dev);
330
331 /* leave reset mode */
332 if (priv->can.state != CAN_STATE_STOPPED)
333 set_reset_mode(dev);
334
335 /* leave reset mode */
336 set_normal_mode(dev);
337 }
338
339 static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
340 {
341 switch (mode) {
342 case CAN_MODE_START:
343 cc770_start(dev);
344 netif_wake_queue(dev);
345 break;
346
347 default:
348 return -EOPNOTSUPP;
349 }
350
351 return 0;
352 }
353
354 static int cc770_set_bittiming(struct net_device *dev)
355 {
356 struct cc770_priv *priv = netdev_priv(dev);
357 struct can_bittiming *bt = &priv->can.bittiming;
358 u8 btr0, btr1;
359
360 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
361 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
362 (((bt->phase_seg2 - 1) & 0x7) << 4);
363 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
364 btr1 |= 0x80;
365
366 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
367
368 cc770_write_reg(priv, bit_timing_0, btr0);
369 cc770_write_reg(priv, bit_timing_1, btr1);
370
371 return 0;
372 }
373
374 static int cc770_get_berr_counter(const struct net_device *dev,
375 struct can_berr_counter *bec)
376 {
377 struct cc770_priv *priv = netdev_priv(dev);
378
379 bec->txerr = cc770_read_reg(priv, tx_error_counter);
380 bec->rxerr = cc770_read_reg(priv, rx_error_counter);
381
382 return 0;
383 }
384
385 static void cc770_tx(struct net_device *dev, int mo)
386 {
387 struct cc770_priv *priv = netdev_priv(dev);
388 struct can_frame *cf = (struct can_frame *)priv->tx_skb->data;
389 u8 dlc, rtr;
390 u32 id;
391 int i;
392
393 dlc = cf->len;
394 id = cf->can_id;
395 rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR;
396
397 cc770_write_reg(priv, msgobj[mo].ctrl0,
398 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
399 cc770_write_reg(priv, msgobj[mo].ctrl1,
400 RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
401
402 if (id & CAN_EFF_FLAG) {
403 id &= CAN_EFF_MASK;
404 cc770_write_reg(priv, msgobj[mo].config,
405 (dlc << 4) | rtr | MSGCFG_XTD);
406 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
407 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
408 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
409 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
410 } else {
411 id &= CAN_SFF_MASK;
412 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
413 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
414 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
415 }
416
417 for (i = 0; i < dlc; i++)
418 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
419
420 cc770_write_reg(priv, msgobj[mo].ctrl1,
421 RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
422 cc770_write_reg(priv, msgobj[mo].ctrl0,
423 MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC);
424 }
425
426 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
427 {
428 struct cc770_priv *priv = netdev_priv(dev);
429 unsigned int mo = obj2msgobj(CC770_OBJ_TX);
430
431 if (can_dropped_invalid_skb(dev, skb))
432 return NETDEV_TX_OK;
433
434 netif_stop_queue(dev);
435
436 if ((cc770_read_reg(priv,
437 msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
438 netdev_err(dev, "TX register is still occupied!\n");
439 return NETDEV_TX_BUSY;
440 }
441
442 priv->tx_skb = skb;
443 cc770_tx(dev, mo);
444
445 return NETDEV_TX_OK;
446 }
447
448 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
449 {
450 struct cc770_priv *priv = netdev_priv(dev);
451 struct net_device_stats *stats = &dev->stats;
452 struct can_frame *cf;
453 struct sk_buff *skb;
454 u8 config;
455 u32 id;
456 int i;
457
458 skb = alloc_can_skb(dev, &cf);
459 if (!skb)
460 return;
461
462 config = cc770_read_reg(priv, msgobj[mo].config);
463
464 if (ctrl1 & RMTPND_SET) {
465 /*
466 * Unfortunately, the chip does not store the real message
467 * identifier of the received remote transmission request
468 * frame. Therefore we set it to 0.
469 */
470 cf->can_id = CAN_RTR_FLAG;
471 if (config & MSGCFG_XTD)
472 cf->can_id |= CAN_EFF_FLAG;
473 cf->len = 0;
474 } else {
475 if (config & MSGCFG_XTD) {
476 id = cc770_read_reg(priv, msgobj[mo].id[3]);
477 id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
478 id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
479 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
480 id >>= 3;
481 id |= CAN_EFF_FLAG;
482 } else {
483 id = cc770_read_reg(priv, msgobj[mo].id[1]);
484 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
485 id >>= 5;
486 }
487
488 cf->can_id = id;
489 cf->len = can_cc_dlc2len((config & 0xf0) >> 4);
490 for (i = 0; i < cf->len; i++)
491 cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
492 }
493
494 stats->rx_packets++;
495 stats->rx_bytes += cf->len;
496 netif_rx(skb);
497 }
498
499 static int cc770_err(struct net_device *dev, u8 status)
500 {
501 struct cc770_priv *priv = netdev_priv(dev);
502 struct net_device_stats *stats = &dev->stats;
503 struct can_frame *cf;
504 struct sk_buff *skb;
505 u8 lec;
506
507 netdev_dbg(dev, "status interrupt (%#x)\n", status);
508
509 skb = alloc_can_err_skb(dev, &cf);
510 if (!skb)
511 return -ENOMEM;
512
513 /* Use extended functions of the CC770 */
514 if (priv->control_normal_mode & CTRL_EAF) {
515 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
516 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
517 }
518
519 if (status & STAT_BOFF) {
520 /* Disable interrupts */
521 cc770_write_reg(priv, control, CTRL_INI);
522 cf->can_id |= CAN_ERR_BUSOFF;
523 priv->can.state = CAN_STATE_BUS_OFF;
524 priv->can.can_stats.bus_off++;
525 can_bus_off(dev);
526 } else if (status & STAT_WARN) {
527 cf->can_id |= CAN_ERR_CRTL;
528 /* Only the CC770 does show error passive */
529 if (cf->data[7] > 127) {
530 cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
531 CAN_ERR_CRTL_TX_PASSIVE;
532 priv->can.state = CAN_STATE_ERROR_PASSIVE;
533 priv->can.can_stats.error_passive++;
534 } else {
535 cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
536 CAN_ERR_CRTL_TX_WARNING;
537 priv->can.state = CAN_STATE_ERROR_WARNING;
538 priv->can.can_stats.error_warning++;
539 }
540 } else {
541 /* Back to error active */
542 cf->can_id |= CAN_ERR_PROT;
543 cf->data[2] = CAN_ERR_PROT_ACTIVE;
544 priv->can.state = CAN_STATE_ERROR_ACTIVE;
545 }
546
547 lec = status & STAT_LEC_MASK;
548 if (lec < 7 && lec > 0) {
549 if (lec == STAT_LEC_ACK) {
550 cf->can_id |= CAN_ERR_ACK;
551 } else {
552 cf->can_id |= CAN_ERR_PROT;
553 switch (lec) {
554 case STAT_LEC_STUFF:
555 cf->data[2] |= CAN_ERR_PROT_STUFF;
556 break;
557 case STAT_LEC_FORM:
558 cf->data[2] |= CAN_ERR_PROT_FORM;
559 break;
560 case STAT_LEC_BIT1:
561 cf->data[2] |= CAN_ERR_PROT_BIT1;
562 break;
563 case STAT_LEC_BIT0:
564 cf->data[2] |= CAN_ERR_PROT_BIT0;
565 break;
566 case STAT_LEC_CRC:
567 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
568 break;
569 }
570 }
571 }
572
573
574 stats->rx_packets++;
575 stats->rx_bytes += cf->len;
576 netif_rx(skb);
577
578 return 0;
579 }
580
581 static 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
599 static 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
640 static 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
664 static 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 struct can_frame *cf;
670 u8 ctrl1;
671
672 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
673
674 cc770_write_reg(priv, msgobj[mo].ctrl0,
675 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
676 cc770_write_reg(priv, msgobj[mo].ctrl1,
677 RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES);
678
679 if (unlikely(!priv->tx_skb)) {
680 netdev_err(dev, "missing tx skb in tx interrupt\n");
681 return;
682 }
683
684 if (unlikely(ctrl1 & MSGLST_SET)) {
685 stats->rx_over_errors++;
686 stats->rx_errors++;
687 }
688
689 /* When the CC770 is sending an RTR message and it receives a regular
690 * message that matches the id of the RTR message, it will overwrite the
691 * outgoing message in the TX register. When this happens we must
692 * process the received message and try to transmit the outgoing skb
693 * again.
694 */
695 if (unlikely(ctrl1 & NEWDAT_SET)) {
696 cc770_rx(dev, mo, ctrl1);
697 cc770_tx(dev, mo);
698 return;
699 }
700
701 cf = (struct can_frame *)priv->tx_skb->data;
702 stats->tx_bytes += cf->len;
703 stats->tx_packets++;
704
705 can_put_echo_skb(priv->tx_skb, dev, 0);
706 can_get_echo_skb(dev, 0);
707 priv->tx_skb = NULL;
708
709 netif_wake_queue(dev);
710 }
711
712 static irqreturn_t cc770_interrupt(int irq, void *dev_id)
713 {
714 struct net_device *dev = (struct net_device *)dev_id;
715 struct cc770_priv *priv = netdev_priv(dev);
716 u8 intid;
717 int o, n = 0;
718
719 /* Shared interrupts and IRQ off? */
720 if (priv->can.state == CAN_STATE_STOPPED)
721 return IRQ_NONE;
722
723 if (priv->pre_irq)
724 priv->pre_irq(priv);
725
726 while (n < CC770_MAX_IRQ) {
727 /* Read the highest pending interrupt request */
728 intid = cc770_read_reg(priv, interrupt);
729 if (!intid)
730 break;
731 n++;
732
733 if (intid == 1) {
734 /* Exit in case of bus-off */
735 if (cc770_status_interrupt(dev))
736 break;
737 } else {
738 o = intid2obj(intid);
739
740 if (o >= CC770_OBJ_MAX) {
741 netdev_err(dev, "Unexpected interrupt id %d\n",
742 intid);
743 continue;
744 }
745
746 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
747 cc770_rtr_interrupt(dev, o);
748 else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
749 cc770_rx_interrupt(dev, o);
750 else
751 cc770_tx_interrupt(dev, o);
752 }
753 }
754
755 if (priv->post_irq)
756 priv->post_irq(priv);
757
758 if (n >= CC770_MAX_IRQ)
759 netdev_dbg(dev, "%d messages handled in ISR", n);
760
761 return (n) ? IRQ_HANDLED : IRQ_NONE;
762 }
763
764 static int cc770_open(struct net_device *dev)
765 {
766 struct cc770_priv *priv = netdev_priv(dev);
767 int err;
768
769 /* set chip into reset mode */
770 set_reset_mode(dev);
771
772 /* common open */
773 err = open_candev(dev);
774 if (err)
775 return err;
776
777 err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
778 dev->name, dev);
779 if (err) {
780 close_candev(dev);
781 return -EAGAIN;
782 }
783
784 /* init and start chip */
785 cc770_start(dev);
786
787 netif_start_queue(dev);
788
789 return 0;
790 }
791
792 static int cc770_close(struct net_device *dev)
793 {
794 netif_stop_queue(dev);
795 set_reset_mode(dev);
796
797 free_irq(dev->irq, dev);
798 close_candev(dev);
799
800 return 0;
801 }
802
803 struct net_device *alloc_cc770dev(int sizeof_priv)
804 {
805 struct net_device *dev;
806 struct cc770_priv *priv;
807
808 dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
809 CC770_ECHO_SKB_MAX);
810 if (!dev)
811 return NULL;
812
813 priv = netdev_priv(dev);
814
815 priv->dev = dev;
816 priv->can.bittiming_const = &cc770_bittiming_const;
817 priv->can.do_set_bittiming = cc770_set_bittiming;
818 priv->can.do_set_mode = cc770_set_mode;
819 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
820 priv->tx_skb = NULL;
821
822 memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
823
824 if (sizeof_priv)
825 priv->priv = (void *)priv + sizeof(struct cc770_priv);
826
827 return dev;
828 }
829 EXPORT_SYMBOL_GPL(alloc_cc770dev);
830
831 void free_cc770dev(struct net_device *dev)
832 {
833 free_candev(dev);
834 }
835 EXPORT_SYMBOL_GPL(free_cc770dev);
836
837 static const struct net_device_ops cc770_netdev_ops = {
838 .ndo_open = cc770_open,
839 .ndo_stop = cc770_close,
840 .ndo_start_xmit = cc770_start_xmit,
841 .ndo_change_mtu = can_change_mtu,
842 };
843
844 int 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
855 dev->flags |= IFF_ECHO; /* we support local echo */
856
857 /* Should we use additional functions? */
858 if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
859 priv->can.do_get_berr_counter = cc770_get_berr_counter;
860 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
861 netdev_dbg(dev, "i82527 mode with additional functions\n");
862 } else {
863 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
864 netdev_dbg(dev, "strict i82527 compatibility mode\n");
865 }
866
867 chipset_init(priv);
868 set_reset_mode(dev);
869
870 return register_candev(dev);
871 }
872 EXPORT_SYMBOL_GPL(register_cc770dev);
873
874 void unregister_cc770dev(struct net_device *dev)
875 {
876 set_reset_mode(dev);
877 unregister_candev(dev);
878 }
879 EXPORT_SYMBOL_GPL(unregister_cc770dev);
880
881 static __init int cc770_init(void)
882 {
883 if (msgobj15_eff) {
884 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
885 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
886 }
887
888 pr_info("CAN netdevice driver\n");
889
890 return 0;
891 }
892 module_init(cc770_init);
893
894 static __exit void cc770_exit(void)
895 {
896 pr_info("driver removed\n");
897 }
898 module_exit(cc770_exit);
Linux with added FPC-III support