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);