1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 *
4 * CTU CAN FD IP Core
5 *
6 * Copyright (C) 2015-2018 Ondrej Ille <ondrej.ille@gmail.com> FEE CTU
7 * Copyright (C) 2018-2021 Ondrej Ille <ondrej.ille@gmail.com> self-funded
8 * Copyright (C) 2018-2019 Martin Jerabek <martin.jerabek01@gmail.com> FEE CTU
9 * Copyright (C) 2018-2022 Pavel Pisa <pisa@cmp.felk.cvut.cz> FEE CTU/self-funded
10 *
11 * Project advisors:
12 *     Jiri Novak <jnovak@fel.cvut.cz>
13 *     Pavel Pisa <pisa@cmp.felk.cvut.cz>
14 *
15 * Department of Measurement         (http://meas.fel.cvut.cz/)
16 * Faculty of Electrical Engineering (http://www.fel.cvut.cz)
17 * Czech Technical University        (http://www.cvut.cz/)
18 ******************************************************************************/
19
20#include <linux/clk.h>
21#include <linux/errno.h>
22#include <linux/ethtool.h>
23#include <linux/init.h>
24#include <linux/bitfield.h>
25#include <linux/interrupt.h>
26#include <linux/io.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/skbuff.h>
30#include <linux/string.h>
31#include <linux/types.h>
32#include <linux/can/error.h>
33#include <linux/pm_runtime.h>
34
35#include "ctucanfd.h"
36#include "ctucanfd_kregs.h"
37#include "ctucanfd_kframe.h"
38
39#ifdef DEBUG
40#define  ctucan_netdev_dbg(ndev, args...) \
41		netdev_dbg(ndev, args)
42#else
43#define ctucan_netdev_dbg(...) do { } while (0)
44#endif
45
46#define CTUCANFD_ID 0xCAFD
47
48/* TX buffer rotation:
49 * - when a buffer transitions to empty state, rotate order and priorities
50 * - if more buffers seem to transition at the same time, rotate by the number of buffers
51 * - it may be assumed that buffers transition to empty state in FIFO order (because we manage
52 *   priorities that way)
53 * - at frame filling, do not rotate anything, just increment buffer modulo counter
54 */
55
56#define CTUCANFD_FLAG_RX_FFW_BUFFERED	1
57
58#define CTUCAN_STATE_TO_TEXT_ENTRY(st) \
59		[st] = #st
60
61enum ctucan_txtb_status {
62	TXT_NOT_EXIST       = 0x0,
63	TXT_RDY             = 0x1,
64	TXT_TRAN            = 0x2,
65	TXT_ABTP            = 0x3,
66	TXT_TOK             = 0x4,
67	TXT_ERR             = 0x6,
68	TXT_ABT             = 0x7,
69	TXT_ETY             = 0x8,
70};
71
72enum ctucan_txtb_command {
73	TXT_CMD_SET_EMPTY   = 0x01,
74	TXT_CMD_SET_READY   = 0x02,
75	TXT_CMD_SET_ABORT   = 0x04
76};
77
78static const struct can_bittiming_const ctu_can_fd_bit_timing_max = {
79	.name = "ctu_can_fd",
80	.tseg1_min = 2,
81	.tseg1_max = 190,
82	.tseg2_min = 1,
83	.tseg2_max = 63,
84	.sjw_max = 31,
85	.brp_min = 1,
86	.brp_max = 8,
87	.brp_inc = 1,
88};
89
90static const struct can_bittiming_const ctu_can_fd_bit_timing_data_max = {
91	.name = "ctu_can_fd",
92	.tseg1_min = 2,
93	.tseg1_max = 94,
94	.tseg2_min = 1,
95	.tseg2_max = 31,
96	.sjw_max = 31,
97	.brp_min = 1,
98	.brp_max = 2,
99	.brp_inc = 1,
100};
101
102static const char * const ctucan_state_strings[CAN_STATE_MAX] = {
103	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_ERROR_ACTIVE),
104	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_ERROR_WARNING),
105	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_ERROR_PASSIVE),
106	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_BUS_OFF),
107	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_STOPPED),
108	CTUCAN_STATE_TO_TEXT_ENTRY(CAN_STATE_SLEEPING)
109};
110
111static void ctucan_write32_le(struct ctucan_priv *priv,
112			      enum ctu_can_fd_can_registers reg, u32 val)
113{
114	iowrite32(val, priv->mem_base + reg);
115}
116
117static void ctucan_write32_be(struct ctucan_priv *priv,
118			      enum ctu_can_fd_can_registers reg, u32 val)
119{
120	iowrite32be(val, priv->mem_base + reg);
121}
122
123static u32 ctucan_read32_le(struct ctucan_priv *priv,
124			    enum ctu_can_fd_can_registers reg)
125{
126	return ioread32(priv->mem_base + reg);
127}
128
129static u32 ctucan_read32_be(struct ctucan_priv *priv,
130			    enum ctu_can_fd_can_registers reg)
131{
132	return ioread32be(priv->mem_base + reg);
133}
134
135static void ctucan_write32(struct ctucan_priv *priv, enum ctu_can_fd_can_registers reg, u32 val)
136{
137	priv->write_reg(priv, reg, val);
138}
139
140static u32 ctucan_read32(struct ctucan_priv *priv, enum ctu_can_fd_can_registers reg)
141{
142	return priv->read_reg(priv, reg);
143}
144
145static void ctucan_write_txt_buf(struct ctucan_priv *priv, enum ctu_can_fd_can_registers buf_base,
146				 u32 offset, u32 val)
147{
148	priv->write_reg(priv, buf_base + offset, val);
149}
150
151#define CTU_CAN_FD_TXTNF(priv) (!!FIELD_GET(REG_STATUS_TXNF, ctucan_read32(priv, CTUCANFD_STATUS)))
152#define CTU_CAN_FD_ENABLED(priv) (!!FIELD_GET(REG_MODE_ENA, ctucan_read32(priv, CTUCANFD_MODE)))
153
154/**
155 * ctucan_state_to_str() - Converts CAN controller state code to corresponding text
156 * @state:	CAN controller state code
157 *
158 * Return: Pointer to string representation of the error state
159 */
160static const char *ctucan_state_to_str(enum can_state state)
161{
162	const char *txt = NULL;
163
164	if (state >= 0 && state < CAN_STATE_MAX)
165		txt = ctucan_state_strings[state];
166	return txt ? txt : "UNKNOWN";
167}
168
169/**
170 * ctucan_reset() - Issues software reset request to CTU CAN FD
171 * @ndev:	Pointer to net_device structure
172 *
173 * Return: 0 for success, -%ETIMEDOUT if CAN controller does not leave reset
174 */
175static int ctucan_reset(struct net_device *ndev)
176{
177	struct ctucan_priv *priv = netdev_priv(ndev);
178	int i = 100;
179
180	ctucan_write32(priv, CTUCANFD_MODE, REG_MODE_RST);
181	clear_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);
182
183	do {
184		u16 device_id = FIELD_GET(REG_DEVICE_ID_DEVICE_ID,
185					  ctucan_read32(priv, CTUCANFD_DEVICE_ID));
186
187		if (device_id == 0xCAFD)
188			return 0;
189		if (!i--) {
190			netdev_warn(ndev, "device did not leave reset\n");
191			return -ETIMEDOUT;
192		}
193		usleep_range(100, 200);
194	} while (1);
195}
196
197/**
198 * ctucan_set_btr() - Sets CAN bus bit timing in CTU CAN FD
199 * @ndev:	Pointer to net_device structure
200 * @bt:		Pointer to Bit timing structure
201 * @nominal:	True - Nominal bit timing, False - Data bit timing
202 *
203 * Return: 0 - OK, -%EPERM if controller is enabled
204 */
205static int ctucan_set_btr(struct net_device *ndev, struct can_bittiming *bt, bool nominal)
206{
207	struct ctucan_priv *priv = netdev_priv(ndev);
208	int max_ph1_len = 31;
209	u32 btr = 0;
210	u32 prop_seg = bt->prop_seg;
211	u32 phase_seg1 = bt->phase_seg1;
212
213	if (CTU_CAN_FD_ENABLED(priv)) {
214		netdev_err(ndev, "BUG! Cannot set bittiming - CAN is enabled\n");
215		return -EPERM;
216	}
217
218	if (nominal)
219		max_ph1_len = 63;
220
221	/* The timing calculation functions have only constraints on tseg1, which is prop_seg +
222	 * phase1_seg combined. tseg1 is then split in half and stored into prog_seg and phase_seg1.
223	 * In CTU CAN FD, PROP is 6/7 bits wide but PH1 only 6/5, so we must re-distribute the
224	 * values here.
225	 */
226	if (phase_seg1 > max_ph1_len) {
227		prop_seg += phase_seg1 - max_ph1_len;
228		phase_seg1 = max_ph1_len;
229		bt->prop_seg = prop_seg;
230		bt->phase_seg1 = phase_seg1;
231	}
232
233	if (nominal) {
234		btr = FIELD_PREP(REG_BTR_PROP, prop_seg);
235		btr |= FIELD_PREP(REG_BTR_PH1, phase_seg1);
236		btr |= FIELD_PREP(REG_BTR_PH2, bt->phase_seg2);
237		btr |= FIELD_PREP(REG_BTR_BRP, bt->brp);
238		btr |= FIELD_PREP(REG_BTR_SJW, bt->sjw);
239
240		ctucan_write32(priv, CTUCANFD_BTR, btr);
241	} else {
242		btr = FIELD_PREP(REG_BTR_FD_PROP_FD, prop_seg);
243		btr |= FIELD_PREP(REG_BTR_FD_PH1_FD, phase_seg1);
244		btr |= FIELD_PREP(REG_BTR_FD_PH2_FD, bt->phase_seg2);
245		btr |= FIELD_PREP(REG_BTR_FD_BRP_FD, bt->brp);
246		btr |= FIELD_PREP(REG_BTR_FD_SJW_FD, bt->sjw);
247
248		ctucan_write32(priv, CTUCANFD_BTR_FD, btr);
249	}
250
251	return 0;
252}
253
254/**
255 * ctucan_set_bittiming() - CAN set nominal bit timing routine
256 * @ndev:	Pointer to net_device structure
257 *
258 * Return: 0 on success, -%EPERM on error
259 */
260static int ctucan_set_bittiming(struct net_device *ndev)
261{
262	struct ctucan_priv *priv = netdev_priv(ndev);
263	struct can_bittiming *bt = &priv->can.bittiming;
264
265	/* Note that bt may be modified here */
266	return ctucan_set_btr(ndev, bt, true);
267}
268
269/**
270 * ctucan_set_data_bittiming() - CAN set data bit timing routine
271 * @ndev:	Pointer to net_device structure
272 *
273 * Return: 0 on success, -%EPERM on error
274 */
275static int ctucan_set_data_bittiming(struct net_device *ndev)
276{
277	struct ctucan_priv *priv = netdev_priv(ndev);
278	struct can_bittiming *dbt = &priv->can.data_bittiming;
279
280	/* Note that dbt may be modified here */
281	return ctucan_set_btr(ndev, dbt, false);
282}
283
284/**
285 * ctucan_set_secondary_sample_point() - Sets secondary sample point in CTU CAN FD
286 * @ndev:	Pointer to net_device structure
287 *
288 * Return: 0 on success, -%EPERM if controller is enabled
289 */
290static int ctucan_set_secondary_sample_point(struct net_device *ndev)
291{
292	struct ctucan_priv *priv = netdev_priv(ndev);
293	struct can_bittiming *dbt = &priv->can.data_bittiming;
294	int ssp_offset = 0;
295	u32 ssp_cfg = 0; /* No SSP by default */
296
297	if (CTU_CAN_FD_ENABLED(priv)) {
298		netdev_err(ndev, "BUG! Cannot set SSP - CAN is enabled\n");
299		return -EPERM;
300	}
301
302	/* Use SSP for bit-rates above 1 Mbits/s */
303	if (dbt->bitrate > 1000000) {
304		/* Calculate SSP in minimal time quanta */
305		ssp_offset = (priv->can.clock.freq / 1000) * dbt->sample_point / dbt->bitrate;
306
307		if (ssp_offset > 127) {
308			netdev_warn(ndev, "SSP offset saturated to 127\n");
309			ssp_offset = 127;
310		}
311
312		ssp_cfg = FIELD_PREP(REG_TRV_DELAY_SSP_OFFSET, ssp_offset);
313		ssp_cfg |= FIELD_PREP(REG_TRV_DELAY_SSP_SRC, 0x1);
314	}
315
316	ctucan_write32(priv, CTUCANFD_TRV_DELAY, ssp_cfg);
317
318	return 0;
319}
320
321/**
322 * ctucan_set_mode() - Sets CTU CAN FDs mode
323 * @priv:	Pointer to private data
324 * @mode:	Pointer to controller modes to be set
325 */
326static void ctucan_set_mode(struct ctucan_priv *priv, const struct can_ctrlmode *mode)
327{
328	u32 mode_reg = ctucan_read32(priv, CTUCANFD_MODE);
329
330	mode_reg = (mode->flags & CAN_CTRLMODE_LOOPBACK) ?
331			(mode_reg | REG_MODE_ILBP) :
332			(mode_reg & ~REG_MODE_ILBP);
333
334	mode_reg = (mode->flags & CAN_CTRLMODE_LISTENONLY) ?
335			(mode_reg | REG_MODE_BMM) :
336			(mode_reg & ~REG_MODE_BMM);
337
338	mode_reg = (mode->flags & CAN_CTRLMODE_FD) ?
339			(mode_reg | REG_MODE_FDE) :
340			(mode_reg & ~REG_MODE_FDE);
341
342	mode_reg = (mode->flags & CAN_CTRLMODE_PRESUME_ACK) ?
343			(mode_reg | REG_MODE_ACF) :
344			(mode_reg & ~REG_MODE_ACF);
345
346	mode_reg = (mode->flags & CAN_CTRLMODE_FD_NON_ISO) ?
347			(mode_reg | REG_MODE_NISOFD) :
348			(mode_reg & ~REG_MODE_NISOFD);
349
350	/* One shot mode supported indirectly via Retransmit limit */
351	mode_reg &= ~FIELD_PREP(REG_MODE_RTRTH, 0xF);
352	mode_reg = (mode->flags & CAN_CTRLMODE_ONE_SHOT) ?
353			(mode_reg | REG_MODE_RTRLE) :
354			(mode_reg & ~REG_MODE_RTRLE);
355
356	/* Some bits fixed:
357	 *   TSTM  - Off, User shall not be able to change REC/TEC by hand during operation
358	 */
359	mode_reg &= ~REG_MODE_TSTM;
360
361	ctucan_write32(priv, CTUCANFD_MODE, mode_reg);
362}
363
364/**
365 * ctucan_chip_start() - This routine starts the driver
366 * @ndev:	Pointer to net_device structure
367 *
368 * Routine expects that chip is in reset state. It setups initial
369 * Tx buffers for FIFO priorities, sets bittiming, enables interrupts,
370 * switches core to operational mode and changes controller
371 * state to %CAN_STATE_STOPPED.
372 *
373 * Return: 0 on success and failure value on error
374 */
375static int ctucan_chip_start(struct net_device *ndev)
376{
377	struct ctucan_priv *priv = netdev_priv(ndev);
378	u32 int_ena, int_msk;
379	u32 mode_reg;
380	int err;
381	struct can_ctrlmode mode;
382
383	priv->txb_prio = 0x01234567;
384	priv->txb_head = 0;
385	priv->txb_tail = 0;
386	ctucan_write32(priv, CTUCANFD_TX_PRIORITY, priv->txb_prio);
387
388	/* Configure bit-rates and ssp */
389	err = ctucan_set_bittiming(ndev);
390	if (err < 0)
391		return err;
392
393	err = ctucan_set_data_bittiming(ndev);
394	if (err < 0)
395		return err;
396
397	err = ctucan_set_secondary_sample_point(ndev);
398	if (err < 0)
399		return err;
400
401	/* Configure modes */
402	mode.flags = priv->can.ctrlmode;
403	mode.mask = 0xFFFFFFFF;
404	ctucan_set_mode(priv, &mode);
405
406	/* Configure interrupts */
407	int_ena = REG_INT_STAT_RBNEI |
408		  REG_INT_STAT_TXBHCI |
409		  REG_INT_STAT_EWLI |
410		  REG_INT_STAT_FCSI;
411
412	/* Bus error reporting -> Allow Error/Arb.lost interrupts */
413	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
414		int_ena |= REG_INT_STAT_ALI |
415			   REG_INT_STAT_BEI;
416	}
417
418	int_msk = ~int_ena; /* Mask all disabled interrupts */
419
420	/* It's after reset, so there is no need to clear anything */
421	ctucan_write32(priv, CTUCANFD_INT_MASK_SET, int_msk);
422	ctucan_write32(priv, CTUCANFD_INT_ENA_SET, int_ena);
423
424	/* Controller enters ERROR_ACTIVE on initial FCSI */
425	priv->can.state = CAN_STATE_STOPPED;
426
427	/* Enable the controller */
428	mode_reg = ctucan_read32(priv, CTUCANFD_MODE);
429	mode_reg |= REG_MODE_ENA;
430	ctucan_write32(priv, CTUCANFD_MODE, mode_reg);
431
432	return 0;
433}
434
435/**
436 * ctucan_do_set_mode() - Sets mode of the driver
437 * @ndev:	Pointer to net_device structure
438 * @mode:	Tells the mode of the driver
439 *
440 * This check the drivers state and calls the corresponding modes to set.
441 *
442 * Return: 0 on success and failure value on error
443 */
444static int ctucan_do_set_mode(struct net_device *ndev, enum can_mode mode)
445{
446	int ret;
447
448	switch (mode) {
449	case CAN_MODE_START:
450		ret = ctucan_reset(ndev);
451		if (ret < 0)
452			return ret;
453		ret = ctucan_chip_start(ndev);
454		if (ret < 0) {
455			netdev_err(ndev, "ctucan_chip_start failed!\n");
456			return ret;
457		}
458		netif_wake_queue(ndev);
459		break;
460	default:
461		ret = -EOPNOTSUPP;
462		break;
463	}
464
465	return ret;
466}
467
468/**
469 * ctucan_get_tx_status() - Gets status of TXT buffer
470 * @priv:	Pointer to private data
471 * @buf:	Buffer index (0-based)
472 *
473 * Return: Status of TXT buffer
474 */
475static enum ctucan_txtb_status ctucan_get_tx_status(struct ctucan_priv *priv, u8 buf)
476{
477	u32 tx_status = ctucan_read32(priv, CTUCANFD_TX_STATUS);
478	enum ctucan_txtb_status status = (tx_status >> (buf * 4)) & 0x7;
479
480	return status;
481}
482
483/**
484 * ctucan_is_txt_buf_writable() - Checks if frame can be inserted to TXT Buffer
485 * @priv:	Pointer to private data
486 * @buf:	Buffer index (0-based)
487 *
488 * Return: True - Frame can be inserted to TXT Buffer, False - If attempted, frame will not be
489 *	   inserted to TXT Buffer
490 */
491static bool ctucan_is_txt_buf_writable(struct ctucan_priv *priv, u8 buf)
492{
493	enum ctucan_txtb_status buf_status;
494
495	buf_status = ctucan_get_tx_status(priv, buf);
496	if (buf_status == TXT_RDY || buf_status == TXT_TRAN || buf_status == TXT_ABTP)
497		return false;
498
499	return true;
500}
501
502/**
503 * ctucan_insert_frame() - Inserts frame to TXT buffer
504 * @priv:	Pointer to private data
505 * @cf:		Pointer to CAN frame to be inserted
506 * @buf:	TXT Buffer index to which frame is inserted (0-based)
507 * @isfdf:	True - CAN FD Frame, False - CAN 2.0 Frame
508 *
509 * Return: True - Frame inserted successfully
510 *	   False - Frame was not inserted due to one of:
511 *			1. TXT Buffer is not writable (it is in wrong state)
512 *			2. Invalid TXT buffer index
513 *			3. Invalid frame length
514 */
515static bool ctucan_insert_frame(struct ctucan_priv *priv, const struct canfd_frame *cf, u8 buf,
516				bool isfdf)
517{
518	u32 buf_base;
519	u32 ffw = 0;
520	u32 idw = 0;
521	unsigned int i;
522
523	if (buf >= priv->ntxbufs)
524		return false;
525
526	if (!ctucan_is_txt_buf_writable(priv, buf))
527		return false;
528
529	if (cf->len > CANFD_MAX_DLEN)
530		return false;
531
532	/* Prepare Frame format */
533	if (cf->can_id & CAN_RTR_FLAG)
534		ffw |= REG_FRAME_FORMAT_W_RTR;
535
536	if (cf->can_id & CAN_EFF_FLAG)
537		ffw |= REG_FRAME_FORMAT_W_IDE;
538
539	if (isfdf) {
540		ffw |= REG_FRAME_FORMAT_W_FDF;
541		if (cf->flags & CANFD_BRS)
542			ffw |= REG_FRAME_FORMAT_W_BRS;
543	}
544
545	ffw |= FIELD_PREP(REG_FRAME_FORMAT_W_DLC, can_fd_len2dlc(cf->len));
546
547	/* Prepare identifier */
548	if (cf->can_id & CAN_EFF_FLAG)
549		idw = cf->can_id & CAN_EFF_MASK;
550	else
551		idw = FIELD_PREP(REG_IDENTIFIER_W_IDENTIFIER_BASE, cf->can_id & CAN_SFF_MASK);
552
553	/* Write ID, Frame format, Don't write timestamp -> Time triggered transmission disabled */
554	buf_base = (buf + 1) * 0x100;
555	ctucan_write_txt_buf(priv, buf_base, CTUCANFD_FRAME_FORMAT_W, ffw);
556	ctucan_write_txt_buf(priv, buf_base, CTUCANFD_IDENTIFIER_W, idw);
557
558	/* Write Data payload */
559	if (!(cf->can_id & CAN_RTR_FLAG)) {
560		for (i = 0; i < cf->len; i += 4) {
561			u32 data = le32_to_cpu(*(__le32 *)(cf->data + i));
562
563			ctucan_write_txt_buf(priv, buf_base, CTUCANFD_DATA_1_4_W + i, data);
564		}
565	}
566
567	return true;
568}
569
570/**
571 * ctucan_give_txtb_cmd() - Applies command on TXT buffer
572 * @priv:	Pointer to private data
573 * @cmd:	Command to give
574 * @buf:	Buffer index (0-based)
575 */
576static void ctucan_give_txtb_cmd(struct ctucan_priv *priv, enum ctucan_txtb_command cmd, u8 buf)
577{
578	u32 tx_cmd = cmd;
579
580	tx_cmd |= 1 << (buf + 8);
581	ctucan_write32(priv, CTUCANFD_TX_COMMAND, tx_cmd);
582}
583
584/**
585 * ctucan_start_xmit() - Starts the transmission
586 * @skb:	sk_buff pointer that contains data to be Txed
587 * @ndev:	Pointer to net_device structure
588 *
589 * Invoked from upper layers to initiate transmission. Uses the next available free TXT Buffer and
590 * populates its fields to start the transmission.
591 *
592 * Return: %NETDEV_TX_OK on success, %NETDEV_TX_BUSY when no free TXT buffer is available,
593 *         negative return values reserved for error cases
594 */
595static netdev_tx_t ctucan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
596{
597	struct ctucan_priv *priv = netdev_priv(ndev);
598	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
599	u32 txtb_id;
600	bool ok;
601	unsigned long flags;
602
603	if (can_dev_dropped_skb(ndev, skb))
604		return NETDEV_TX_OK;
605
606	if (unlikely(!CTU_CAN_FD_TXTNF(priv))) {
607		netif_stop_queue(ndev);
608		netdev_err(ndev, "BUG!, no TXB free when queue awake!\n");
609		return NETDEV_TX_BUSY;
610	}
611
612	txtb_id = priv->txb_head % priv->ntxbufs;
613	ctucan_netdev_dbg(ndev, "%s: using TXB#%u\n", __func__, txtb_id);
614	ok = ctucan_insert_frame(priv, cf, txtb_id, can_is_canfd_skb(skb));
615
616	if (!ok) {
617		netdev_err(ndev, "BUG! TXNF set but cannot insert frame into TXTB! HW Bug?");
618		kfree_skb(skb);
619		ndev->stats.tx_dropped++;
620		return NETDEV_TX_OK;
621	}
622
623	can_put_echo_skb(skb, ndev, txtb_id, 0);
624
625	spin_lock_irqsave(&priv->tx_lock, flags);
626	ctucan_give_txtb_cmd(priv, TXT_CMD_SET_READY, txtb_id);
627	priv->txb_head++;
628
629	/* Check if all TX buffers are full */
630	if (!CTU_CAN_FD_TXTNF(priv))
631		netif_stop_queue(ndev);
632
633	spin_unlock_irqrestore(&priv->tx_lock, flags);
634
635	return NETDEV_TX_OK;
636}
637
638/**
639 * ctucan_read_rx_frame() - Reads frame from RX FIFO
640 * @priv:	Pointer to CTU CAN FD's private data
641 * @cf:		Pointer to CAN frame struct
642 * @ffw:	Previously read frame format word
643 *
644 * Note: Frame format word must be read separately and provided in 'ffw'.
645 */
646static void ctucan_read_rx_frame(struct ctucan_priv *priv, struct canfd_frame *cf, u32 ffw)
647{
648	u32 idw;
649	unsigned int i;
650	unsigned int wc;
651	unsigned int len;
652
653	idw = ctucan_read32(priv, CTUCANFD_RX_DATA);
654	if (FIELD_GET(REG_FRAME_FORMAT_W_IDE, ffw))
655		cf->can_id = (idw & CAN_EFF_MASK) | CAN_EFF_FLAG;
656	else
657		cf->can_id = (idw >> 18) & CAN_SFF_MASK;
658
659	/* BRS, ESI, RTR Flags */
660	if (FIELD_GET(REG_FRAME_FORMAT_W_FDF, ffw)) {
661		if (FIELD_GET(REG_FRAME_FORMAT_W_BRS, ffw))
662			cf->flags |= CANFD_BRS;
663		if (FIELD_GET(REG_FRAME_FORMAT_W_ESI_RSV, ffw))
664			cf->flags |= CANFD_ESI;
665	} else if (FIELD_GET(REG_FRAME_FORMAT_W_RTR, ffw)) {
666		cf->can_id |= CAN_RTR_FLAG;
667	}
668
669	wc = FIELD_GET(REG_FRAME_FORMAT_W_RWCNT, ffw) - 3;
670
671	/* DLC */
672	if (FIELD_GET(REG_FRAME_FORMAT_W_DLC, ffw) <= 8) {
673		len = FIELD_GET(REG_FRAME_FORMAT_W_DLC, ffw);
674	} else {
675		if (FIELD_GET(REG_FRAME_FORMAT_W_FDF, ffw))
676			len = wc << 2;
677		else
678			len = 8;
679	}
680	cf->len = len;
681	if (unlikely(len > wc * 4))
682		len = wc * 4;
683
684	/* Timestamp - Read and throw away */
685	ctucan_read32(priv, CTUCANFD_RX_DATA);
686	ctucan_read32(priv, CTUCANFD_RX_DATA);
687
688	/* Data */
689	for (i = 0; i < len; i += 4) {
690		u32 data = ctucan_read32(priv, CTUCANFD_RX_DATA);
691		*(__le32 *)(cf->data + i) = cpu_to_le32(data);
692	}
693	while (unlikely(i < wc * 4)) {
694		ctucan_read32(priv, CTUCANFD_RX_DATA);
695		i += 4;
696	}
697}
698
699/**
700 * ctucan_rx() -  Called from CAN ISR to complete the received frame processing
701 * @ndev:	Pointer to net_device structure
702 *
703 * This function is invoked from the CAN isr(poll) to process the Rx frames. It does minimal
704 * processing and invokes "netif_receive_skb" to complete further processing.
705 * Return: 1 when frame is passed to the network layer, 0 when the first frame word is read but
706 *	   system is out of free SKBs temporally and left code to resolve SKB allocation later,
707 *         -%EAGAIN in a case of empty Rx FIFO.
708 */
709static int ctucan_rx(struct net_device *ndev)
710{
711	struct ctucan_priv *priv = netdev_priv(ndev);
712	struct net_device_stats *stats = &ndev->stats;
713	struct canfd_frame *cf;
714	struct sk_buff *skb;
715	u32 ffw;
716
717	if (test_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags)) {
718		ffw = priv->rxfrm_first_word;
719		clear_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);
720	} else {
721		ffw = ctucan_read32(priv, CTUCANFD_RX_DATA);
722	}
723
724	if (!FIELD_GET(REG_FRAME_FORMAT_W_RWCNT, ffw))
725		return -EAGAIN;
726
727	if (FIELD_GET(REG_FRAME_FORMAT_W_FDF, ffw))
728		skb = alloc_canfd_skb(ndev, &cf);
729	else
730		skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
731
732	if (unlikely(!skb)) {
733		priv->rxfrm_first_word = ffw;
734		set_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);
735		return 0;
736	}
737
738	ctucan_read_rx_frame(priv, cf, ffw);
739
740	stats->rx_bytes += cf->len;
741	stats->rx_packets++;
742	netif_receive_skb(skb);
743
744	return 1;
745}
746
747/**
748 * ctucan_read_fault_state() - Reads CTU CAN FDs fault confinement state.
749 * @priv:	Pointer to private data
750 *
751 * Returns: Fault confinement state of controller
752 */
753static enum can_state ctucan_read_fault_state(struct ctucan_priv *priv)
754{
755	u32 fs;
756	u32 rec_tec;
757	u32 ewl;
758
759	fs = ctucan_read32(priv, CTUCANFD_EWL);
760	rec_tec = ctucan_read32(priv, CTUCANFD_REC);
761	ewl = FIELD_GET(REG_EWL_EW_LIMIT, fs);
762
763	if (FIELD_GET(REG_EWL_ERA, fs)) {
764		if (ewl > FIELD_GET(REG_REC_REC_VAL, rec_tec) &&
765		    ewl > FIELD_GET(REG_REC_TEC_VAL, rec_tec))
766			return CAN_STATE_ERROR_ACTIVE;
767		else
768			return CAN_STATE_ERROR_WARNING;
769	} else if (FIELD_GET(REG_EWL_ERP, fs)) {
770		return CAN_STATE_ERROR_PASSIVE;
771	} else if (FIELD_GET(REG_EWL_BOF, fs)) {
772		return CAN_STATE_BUS_OFF;
773	}
774
775	WARN(true, "Invalid error state");
776	return CAN_STATE_ERROR_PASSIVE;
777}
778
779/**
780 * ctucan_get_rec_tec() - Reads REC/TEC counter values from controller
781 * @priv:	Pointer to private data
782 * @bec:	Pointer to Error counter structure
783 */
784static void ctucan_get_rec_tec(struct ctucan_priv *priv, struct can_berr_counter *bec)
785{
786	u32 err_ctrs = ctucan_read32(priv, CTUCANFD_REC);
787
788	bec->rxerr = FIELD_GET(REG_REC_REC_VAL, err_ctrs);
789	bec->txerr = FIELD_GET(REG_REC_TEC_VAL, err_ctrs);
790}
791
792/**
793 * ctucan_err_interrupt() - Error frame ISR
794 * @ndev:	net_device pointer
795 * @isr:	interrupt status register value
796 *
797 * This is the CAN error interrupt and it will check the type of error and forward the error
798 * frame to upper layers.
799 */
800static void ctucan_err_interrupt(struct net_device *ndev, u32 isr)
801{
802	struct ctucan_priv *priv = netdev_priv(ndev);
803	struct net_device_stats *stats = &ndev->stats;
804	struct can_frame *cf;
805	struct sk_buff *skb;
806	enum can_state state;
807	struct can_berr_counter bec;
808	u32 err_capt_alc;
809	int dologerr = net_ratelimit();
810
811	ctucan_get_rec_tec(priv, &bec);
812	state = ctucan_read_fault_state(priv);
813	err_capt_alc = ctucan_read32(priv, CTUCANFD_ERR_CAPT);
814
815	if (dologerr)
816		netdev_info(ndev, "%s: ISR = 0x%08x, rxerr %d, txerr %d, error type %lu, pos %lu, ALC id_field %lu, bit %lu\n",
817			    __func__, isr, bec.rxerr, bec.txerr,
818			    FIELD_GET(REG_ERR_CAPT_ERR_TYPE, err_capt_alc),
819			    FIELD_GET(REG_ERR_CAPT_ERR_POS, err_capt_alc),
820			    FIELD_GET(REG_ERR_CAPT_ALC_ID_FIELD, err_capt_alc),
821			    FIELD_GET(REG_ERR_CAPT_ALC_BIT, err_capt_alc));
822
823	skb = alloc_can_err_skb(ndev, &cf);
824
825	/* EWLI: error warning limit condition met
826	 * FCSI: fault confinement state changed
827	 * ALI:  arbitration lost (just informative)
828	 * BEI:  bus error interrupt
829	 */
830	if (FIELD_GET(REG_INT_STAT_FCSI, isr) || FIELD_GET(REG_INT_STAT_EWLI, isr)) {
831		netdev_info(ndev, "state changes from %s to %s\n",
832			    ctucan_state_to_str(priv->can.state),
833			    ctucan_state_to_str(state));
834
835		if (priv->can.state == state)
836			netdev_warn(ndev,
837				    "current and previous state is the same! (missed interrupt?)\n");
838
839		priv->can.state = state;
840		switch (state) {
841		case CAN_STATE_BUS_OFF:
842			priv->can.can_stats.bus_off++;
843			can_bus_off(ndev);
844			if (skb)
845				cf->can_id |= CAN_ERR_BUSOFF;
846			break;
847		case CAN_STATE_ERROR_PASSIVE:
848			priv->can.can_stats.error_passive++;
849			if (skb) {
850				cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
851				cf->data[1] = (bec.rxerr > 127) ?
852						CAN_ERR_CRTL_RX_PASSIVE :
853						CAN_ERR_CRTL_TX_PASSIVE;
854				cf->data[6] = bec.txerr;
855				cf->data[7] = bec.rxerr;
856			}
857			break;
858		case CAN_STATE_ERROR_WARNING:
859			priv->can.can_stats.error_warning++;
860			if (skb) {
861				cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
862				cf->data[1] |= (bec.txerr > bec.rxerr) ?
863					CAN_ERR_CRTL_TX_WARNING :
864					CAN_ERR_CRTL_RX_WARNING;
865				cf->data[6] = bec.txerr;
866				cf->data[7] = bec.rxerr;
867			}
868			break;
869		case CAN_STATE_ERROR_ACTIVE:
870			cf->can_id |= CAN_ERR_CNT;
871			cf->data[1] = CAN_ERR_CRTL_ACTIVE;
872			cf->data[6] = bec.txerr;
873			cf->data[7] = bec.rxerr;
874			break;
875		default:
876			netdev_warn(ndev, "unhandled error state (%d:%s)!\n",
877				    state, ctucan_state_to_str(state));
878			break;
879		}
880	}
881
882	/* Check for Arbitration Lost interrupt */
883	if (FIELD_GET(REG_INT_STAT_ALI, isr)) {
884		if (dologerr)
885			netdev_info(ndev, "arbitration lost\n");
886		priv->can.can_stats.arbitration_lost++;
887		if (skb) {
888			cf->can_id |= CAN_ERR_LOSTARB;
889			cf->data[0] = CAN_ERR_LOSTARB_UNSPEC;
890		}
891	}
892
893	/* Check for Bus Error interrupt */
894	if (FIELD_GET(REG_INT_STAT_BEI, isr)) {
895		netdev_info(ndev, "bus error\n");
896		priv->can.can_stats.bus_error++;
897		stats->rx_errors++;
898		if (skb) {
899			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
900			cf->data[2] = CAN_ERR_PROT_UNSPEC;
901			cf->data[3] = CAN_ERR_PROT_LOC_UNSPEC;
902		}
903	}
904
905	if (skb) {
906		stats->rx_packets++;
907		stats->rx_bytes += cf->can_dlc;
908		netif_rx(skb);
909	}
910}
911
912/**
913 * ctucan_rx_poll() - Poll routine for rx packets (NAPI)
914 * @napi:	NAPI structure pointer
915 * @quota:	Max number of rx packets to be processed.
916 *
917 * This is the poll routine for rx part. It will process the packets maximux quota value.
918 *
919 * Return: Number of packets received
920 */
921static int ctucan_rx_poll(struct napi_struct *napi, int quota)
922{
923	struct net_device *ndev = napi->dev;
924	struct ctucan_priv *priv = netdev_priv(ndev);
925	int work_done = 0;
926	u32 status;
927	u32 framecnt;
928	int res = 1;
929
930	framecnt = FIELD_GET(REG_RX_STATUS_RXFRC, ctucan_read32(priv, CTUCANFD_RX_STATUS));
931	while (framecnt && work_done < quota && res > 0) {
932		res = ctucan_rx(ndev);
933		work_done++;
934		framecnt = FIELD_GET(REG_RX_STATUS_RXFRC, ctucan_read32(priv, CTUCANFD_RX_STATUS));
935	}
936
937	/* Check for RX FIFO Overflow */
938	status = ctucan_read32(priv, CTUCANFD_STATUS);
939	if (FIELD_GET(REG_STATUS_DOR, status)) {
940		struct net_device_stats *stats = &ndev->stats;
941		struct can_frame *cf;
942		struct sk_buff *skb;
943
944		netdev_info(ndev, "rx_poll: rx fifo overflow\n");
945		stats->rx_over_errors++;
946		stats->rx_errors++;
947		skb = alloc_can_err_skb(ndev, &cf);
948		if (skb) {
949			cf->can_id |= CAN_ERR_CRTL;
950			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
951			stats->rx_packets++;
952			stats->rx_bytes += cf->can_dlc;
953			netif_rx(skb);
954		}
955
956		/* Clear Data Overrun */
957		ctucan_write32(priv, CTUCANFD_COMMAND, REG_COMMAND_CDO);
958	}
959
960	if (!framecnt && res != 0) {
961		if (napi_complete_done(napi, work_done)) {
962			/* Clear and enable RBNEI. It is level-triggered, so
963			 * there is no race condition.
964			 */
965			ctucan_write32(priv, CTUCANFD_INT_STAT, REG_INT_STAT_RBNEI);
966			ctucan_write32(priv, CTUCANFD_INT_MASK_CLR, REG_INT_STAT_RBNEI);
967		}
968	}
969
970	return work_done;
971}
972
973/**
974 * ctucan_rotate_txb_prio() - Rotates priorities of TXT Buffers
975 * @ndev:	net_device pointer
976 */
977static void ctucan_rotate_txb_prio(struct net_device *ndev)
978{
979	struct ctucan_priv *priv = netdev_priv(ndev);
980	u32 prio = priv->txb_prio;
981
982	prio = (prio << 4) | ((prio >> ((priv->ntxbufs - 1) * 4)) & 0xF);
983	ctucan_netdev_dbg(ndev, "%s: from 0x%08x to 0x%08x\n", __func__, priv->txb_prio, prio);
984	priv->txb_prio = prio;
985	ctucan_write32(priv, CTUCANFD_TX_PRIORITY, prio);
986}
987
988/**
989 * ctucan_tx_interrupt() - Tx done Isr
990 * @ndev:	net_device pointer
991 */
992static void ctucan_tx_interrupt(struct net_device *ndev)
993{
994	struct ctucan_priv *priv = netdev_priv(ndev);
995	struct net_device_stats *stats = &ndev->stats;
996	bool first = true;
997	bool some_buffers_processed;
998	unsigned long flags;
999	enum ctucan_txtb_status txtb_status;
1000	u32 txtb_id;
1001
1002	/*  read tx_status
1003	 *  if txb[n].finished (bit 2)
1004	 *	if ok -> echo
1005	 *	if error / aborted -> ?? (find how to handle oneshot mode)
1006	 *	txb_tail++
1007	 */
1008	do {
1009		spin_lock_irqsave(&priv->tx_lock, flags);
1010
1011		some_buffers_processed = false;
1012		while ((int)(priv->txb_head - priv->txb_tail) > 0) {
1013			txtb_id = priv->txb_tail % priv->ntxbufs;
1014			txtb_status = ctucan_get_tx_status(priv, txtb_id);
1015
1016			ctucan_netdev_dbg(ndev, "TXI: TXB#%u: status 0x%x\n", txtb_id, txtb_status);
1017
1018			switch (txtb_status) {
1019			case TXT_TOK:
1020				ctucan_netdev_dbg(ndev, "TXT_OK\n");
1021				stats->tx_bytes += can_get_echo_skb(ndev, txtb_id, NULL);
1022				stats->tx_packets++;
1023				break;
1024			case TXT_ERR:
1025				/* This indicated that retransmit limit has been reached. Obviously
1026				 * we should not echo the frame, but also not indicate any kind of
1027				 * error. If desired, it was already reported (possible multiple
1028				 * times) on each arbitration lost.
1029				 */
1030				netdev_warn(ndev, "TXB in Error state\n");
1031				can_free_echo_skb(ndev, txtb_id, NULL);
1032				stats->tx_dropped++;
1033				break;
1034			case TXT_ABT:
1035				/* Same as for TXT_ERR, only with different cause. We *could*
1036				 * re-queue the frame, but multiqueue/abort is not supported yet
1037				 * anyway.
1038				 */
1039				netdev_warn(ndev, "TXB in Aborted state\n");
1040				can_free_echo_skb(ndev, txtb_id, NULL);
1041				stats->tx_dropped++;
1042				break;
1043			default:
1044				/* Bug only if the first buffer is not finished, otherwise it is
1045				 * pretty much expected.
1046				 */
1047				if (first) {
1048					netdev_err(ndev,
1049						   "BUG: TXB#%u not in a finished state (0x%x)!\n",
1050						   txtb_id, txtb_status);
1051					spin_unlock_irqrestore(&priv->tx_lock, flags);
1052					/* do not clear nor wake */
1053					return;
1054				}
1055				goto clear;
1056			}
1057			priv->txb_tail++;
1058			first = false;
1059			some_buffers_processed = true;
1060			/* Adjust priorities *before* marking the buffer as empty. */
1061			ctucan_rotate_txb_prio(ndev);
1062			ctucan_give_txtb_cmd(priv, TXT_CMD_SET_EMPTY, txtb_id);
1063		}
1064clear:
1065		spin_unlock_irqrestore(&priv->tx_lock, flags);
1066
1067		/* If no buffers were processed this time, we cannot clear - that would introduce
1068		 * a race condition.
1069		 */
1070		if (some_buffers_processed) {
1071			/* Clear the interrupt again. We do not want to receive again interrupt for
1072			 * the buffer already handled. If it is the last finished one then it would
1073			 * cause log of spurious interrupt.
1074			 */
1075			ctucan_write32(priv, CTUCANFD_INT_STAT, REG_INT_STAT_TXBHCI);
1076		}
1077	} while (some_buffers_processed);
1078
1079	spin_lock_irqsave(&priv->tx_lock, flags);
1080
1081	/* Check if at least one TX buffer is free */
1082	if (CTU_CAN_FD_TXTNF(priv))
1083		netif_wake_queue(ndev);
1084
1085	spin_unlock_irqrestore(&priv->tx_lock, flags);
1086}
1087
1088/**
1089 * ctucan_interrupt() - CAN Isr
1090 * @irq:	irq number
1091 * @dev_id:	device id pointer
1092 *
1093 * This is the CTU CAN FD ISR. It checks for the type of interrupt
1094 * and invokes the corresponding ISR.
1095 *
1096 * Return:
1097 * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
1098 */
1099static irqreturn_t ctucan_interrupt(int irq, void *dev_id)
1100{
1101	struct net_device *ndev = (struct net_device *)dev_id;
1102	struct ctucan_priv *priv = netdev_priv(ndev);
1103	u32 isr, icr;
1104	u32 imask;
1105	int irq_loops;
1106
1107	for (irq_loops = 0; irq_loops < 10000; irq_loops++) {
1108		/* Get the interrupt status */
1109		isr = ctucan_read32(priv, CTUCANFD_INT_STAT);
1110
1111		if (!isr)
1112			return irq_loops ? IRQ_HANDLED : IRQ_NONE;
1113
1114		/* Receive Buffer Not Empty Interrupt */
1115		if (FIELD_GET(REG_INT_STAT_RBNEI, isr)) {
1116			ctucan_netdev_dbg(ndev, "RXBNEI\n");
1117			/* Mask RXBNEI the first, then clear interrupt and schedule NAPI. Even if
1118			 * another IRQ fires, RBNEI will always be 0 (masked).
1119			 */
1120			icr = REG_INT_STAT_RBNEI;
1121			ctucan_write32(priv, CTUCANFD_INT_MASK_SET, icr);
1122			ctucan_write32(priv, CTUCANFD_INT_STAT, icr);
1123			napi_schedule(&priv->napi);
1124		}
1125
1126		/* TXT Buffer HW Command Interrupt */
1127		if (FIELD_GET(REG_INT_STAT_TXBHCI, isr)) {
1128			ctucan_netdev_dbg(ndev, "TXBHCI\n");
1129			/* Cleared inside */
1130			ctucan_tx_interrupt(ndev);
1131		}
1132
1133		/* Error interrupts */
1134		if (FIELD_GET(REG_INT_STAT_EWLI, isr) ||
1135		    FIELD_GET(REG_INT_STAT_FCSI, isr) ||
1136		    FIELD_GET(REG_INT_STAT_ALI, isr)) {
1137			icr = isr & (REG_INT_STAT_EWLI | REG_INT_STAT_FCSI | REG_INT_STAT_ALI);
1138
1139			ctucan_netdev_dbg(ndev, "some ERR interrupt: clearing 0x%08x\n", icr);
1140			ctucan_write32(priv, CTUCANFD_INT_STAT, icr);
1141			ctucan_err_interrupt(ndev, isr);
1142		}
1143		/* Ignore RI, TI, LFI, RFI, BSI */
1144	}
1145
1146	netdev_err(ndev, "%s: stuck interrupt (isr=0x%08x), stopping\n", __func__, isr);
1147
1148	if (FIELD_GET(REG_INT_STAT_TXBHCI, isr)) {
1149		int i;
1150
1151		netdev_err(ndev, "txb_head=0x%08x txb_tail=0x%08x\n",
1152			   priv->txb_head, priv->txb_tail);
1153		for (i = 0; i < priv->ntxbufs; i++) {
1154			u32 status = ctucan_get_tx_status(priv, i);
1155
1156			netdev_err(ndev, "txb[%d] txb status=0x%08x\n", i, status);
1157		}
1158	}
1159
1160	imask = 0xffffffff;
1161	ctucan_write32(priv, CTUCANFD_INT_ENA_CLR, imask);
1162	ctucan_write32(priv, CTUCANFD_INT_MASK_SET, imask);
1163
1164	return IRQ_HANDLED;
1165}
1166
1167/**
1168 * ctucan_chip_stop() - Driver stop routine
1169 * @ndev:	Pointer to net_device structure
1170 *
1171 * This is the drivers stop routine. It will disable the
1172 * interrupts and disable the controller.
1173 */
1174static void ctucan_chip_stop(struct net_device *ndev)
1175{
1176	struct ctucan_priv *priv = netdev_priv(ndev);
1177	u32 mask = 0xffffffff;
1178	u32 mode;
1179
1180	/* Disable interrupts and disable CAN */
1181	ctucan_write32(priv, CTUCANFD_INT_ENA_CLR, mask);
1182	ctucan_write32(priv, CTUCANFD_INT_MASK_SET, mask);
1183	mode = ctucan_read32(priv, CTUCANFD_MODE);
1184	mode &= ~REG_MODE_ENA;
1185	ctucan_write32(priv, CTUCANFD_MODE, mode);
1186
1187	priv->can.state = CAN_STATE_STOPPED;
1188}
1189
1190/**
1191 * ctucan_open() - Driver open routine
1192 * @ndev:	Pointer to net_device structure
1193 *
1194 * This is the driver open routine.
1195 * Return: 0 on success and failure value on error
1196 */
1197static int ctucan_open(struct net_device *ndev)
1198{
1199	struct ctucan_priv *priv = netdev_priv(ndev);
1200	int ret;
1201
1202	ret = pm_runtime_get_sync(priv->dev);
1203	if (ret < 0) {
1204		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1205			   __func__, ret);
1206		pm_runtime_put_noidle(priv->dev);
1207		return ret;
1208	}
1209
1210	ret = ctucan_reset(ndev);
1211	if (ret < 0)
1212		goto err_reset;
1213
1214	/* Common open */
1215	ret = open_candev(ndev);
1216	if (ret) {
1217		netdev_warn(ndev, "open_candev failed!\n");
1218		goto err_open;
1219	}
1220
1221	ret = request_irq(ndev->irq, ctucan_interrupt, priv->irq_flags, ndev->name, ndev);
1222	if (ret < 0) {
1223		netdev_err(ndev, "irq allocation for CAN failed\n");
1224		goto err_irq;
1225	}
1226
1227	ret = ctucan_chip_start(ndev);
1228	if (ret < 0) {
1229		netdev_err(ndev, "ctucan_chip_start failed!\n");
1230		goto err_chip_start;
1231	}
1232
1233	netdev_info(ndev, "ctu_can_fd device registered\n");
1234	napi_enable(&priv->napi);
1235	netif_start_queue(ndev);
1236
1237	return 0;
1238
1239err_chip_start:
1240	free_irq(ndev->irq, ndev);
1241err_irq:
1242	close_candev(ndev);
1243err_open:
1244err_reset:
1245	pm_runtime_put(priv->dev);
1246
1247	return ret;
1248}
1249
1250/**
1251 * ctucan_close() - Driver close routine
1252 * @ndev:	Pointer to net_device structure
1253 *
1254 * Return: 0 always
1255 */
1256static int ctucan_close(struct net_device *ndev)
1257{
1258	struct ctucan_priv *priv = netdev_priv(ndev);
1259
1260	netif_stop_queue(ndev);
1261	napi_disable(&priv->napi);
1262	ctucan_chip_stop(ndev);
1263	free_irq(ndev->irq, ndev);
1264	close_candev(ndev);
1265
1266	pm_runtime_put(priv->dev);
1267
1268	return 0;
1269}
1270
1271/**
1272 * ctucan_get_berr_counter() - error counter routine
1273 * @ndev:	Pointer to net_device structure
1274 * @bec:	Pointer to can_berr_counter structure
1275 *
1276 * This is the driver error counter routine.
1277 * Return: 0 on success and failure value on error
1278 */
1279static int ctucan_get_berr_counter(const struct net_device *ndev, struct can_berr_counter *bec)
1280{
1281	struct ctucan_priv *priv = netdev_priv(ndev);
1282	int ret;
1283
1284	ret = pm_runtime_get_sync(priv->dev);
1285	if (ret < 0) {
1286		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", __func__, ret);
1287		pm_runtime_put_noidle(priv->dev);
1288		return ret;
1289	}
1290
1291	ctucan_get_rec_tec(priv, bec);
1292	pm_runtime_put(priv->dev);
1293
1294	return 0;
1295}
1296
1297static const struct net_device_ops ctucan_netdev_ops = {
1298	.ndo_open	= ctucan_open,
1299	.ndo_stop	= ctucan_close,
1300	.ndo_start_xmit	= ctucan_start_xmit,
1301	.ndo_change_mtu	= can_change_mtu,
1302};
1303
1304static const struct ethtool_ops ctucan_ethtool_ops = {
1305	.get_ts_info = ethtool_op_get_ts_info,
1306};
1307
1308int ctucan_suspend(struct device *dev)
1309{
1310	struct net_device *ndev = dev_get_drvdata(dev);
1311	struct ctucan_priv *priv = netdev_priv(ndev);
1312
1313	if (netif_running(ndev)) {
1314		netif_stop_queue(ndev);
1315		netif_device_detach(ndev);
1316	}
1317
1318	priv->can.state = CAN_STATE_SLEEPING;
1319
1320	return 0;
1321}
1322EXPORT_SYMBOL(ctucan_suspend);
1323
1324int ctucan_resume(struct device *dev)
1325{
1326	struct net_device *ndev = dev_get_drvdata(dev);
1327	struct ctucan_priv *priv = netdev_priv(ndev);
1328
1329	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1330
1331	if (netif_running(ndev)) {
1332		netif_device_attach(ndev);
1333		netif_start_queue(ndev);
1334	}
1335
1336	return 0;
1337}
1338EXPORT_SYMBOL(ctucan_resume);
1339
1340int ctucan_probe_common(struct device *dev, void __iomem *addr, int irq, unsigned int ntxbufs,
1341			unsigned long can_clk_rate, int pm_enable_call,
1342			void (*set_drvdata_fnc)(struct device *dev, struct net_device *ndev))
1343{
1344	struct ctucan_priv *priv;
1345	struct net_device *ndev;
1346	int ret;
1347
1348	/* Create a CAN device instance */
1349	ndev = alloc_candev(sizeof(struct ctucan_priv), ntxbufs);
1350	if (!ndev)
1351		return -ENOMEM;
1352
1353	priv = netdev_priv(ndev);
1354	spin_lock_init(&priv->tx_lock);
1355	INIT_LIST_HEAD(&priv->peers_on_pdev);
1356	priv->ntxbufs = ntxbufs;
1357	priv->dev = dev;
1358	priv->can.bittiming_const = &ctu_can_fd_bit_timing_max;
1359	priv->can.data_bittiming_const = &ctu_can_fd_bit_timing_data_max;
1360	priv->can.do_set_mode = ctucan_do_set_mode;
1361
1362	/* Needed for timing adjustment to be performed as soon as possible */
1363	priv->can.do_set_bittiming = ctucan_set_bittiming;
1364	priv->can.do_set_data_bittiming = ctucan_set_data_bittiming;
1365
1366	priv->can.do_get_berr_counter = ctucan_get_berr_counter;
1367	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK
1368					| CAN_CTRLMODE_LISTENONLY
1369					| CAN_CTRLMODE_FD
1370					| CAN_CTRLMODE_PRESUME_ACK
1371					| CAN_CTRLMODE_BERR_REPORTING
1372					| CAN_CTRLMODE_FD_NON_ISO
1373					| CAN_CTRLMODE_ONE_SHOT;
1374	priv->mem_base = addr;
1375
1376	/* Get IRQ for the device */
1377	ndev->irq = irq;
1378	ndev->flags |= IFF_ECHO;	/* We support local echo */
1379
1380	if (set_drvdata_fnc)
1381		set_drvdata_fnc(dev, ndev);
1382	SET_NETDEV_DEV(ndev, dev);
1383	ndev->netdev_ops = &ctucan_netdev_ops;
1384	ndev->ethtool_ops = &ctucan_ethtool_ops;
1385
1386	/* Getting the can_clk info */
1387	if (!can_clk_rate) {
1388		priv->can_clk = devm_clk_get(dev, NULL);
1389		if (IS_ERR(priv->can_clk)) {
1390			dev_err(dev, "Device clock not found.\n");
1391			ret = PTR_ERR(priv->can_clk);
1392			goto err_free;
1393		}
1394		can_clk_rate = clk_get_rate(priv->can_clk);
1395	}
1396
1397	priv->write_reg = ctucan_write32_le;
1398	priv->read_reg = ctucan_read32_le;
1399
1400	if (pm_enable_call)
1401		pm_runtime_enable(dev);
1402	ret = pm_runtime_get_sync(dev);
1403	if (ret < 0) {
1404		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1405			   __func__, ret);
1406		pm_runtime_put_noidle(priv->dev);
1407		goto err_pmdisable;
1408	}
1409
1410	/* Check for big-endianity and set according IO-accessors */
1411	if ((ctucan_read32(priv, CTUCANFD_DEVICE_ID) & 0xFFFF) != CTUCANFD_ID) {
1412		priv->write_reg = ctucan_write32_be;
1413		priv->read_reg = ctucan_read32_be;
1414		if ((ctucan_read32(priv, CTUCANFD_DEVICE_ID) & 0xFFFF) != CTUCANFD_ID) {
1415			netdev_err(ndev, "CTU_CAN_FD signature not found\n");
1416			ret = -ENODEV;
1417			goto err_deviceoff;
1418		}
1419	}
1420
1421	ret = ctucan_reset(ndev);
1422	if (ret < 0)
1423		goto err_deviceoff;
1424
1425	priv->can.clock.freq = can_clk_rate;
1426
1427	netif_napi_add(ndev, &priv->napi, ctucan_rx_poll);
1428
1429	ret = register_candev(ndev);
1430	if (ret) {
1431		dev_err(dev, "fail to register failed (err=%d)\n", ret);
1432		goto err_deviceoff;
1433	}
1434
1435	pm_runtime_put(dev);
1436
1437	netdev_dbg(ndev, "mem_base=0x%p irq=%d clock=%d, no. of txt buffers:%d\n",
1438		   priv->mem_base, ndev->irq, priv->can.clock.freq, priv->ntxbufs);
1439
1440	return 0;
1441
1442err_deviceoff:
1443	pm_runtime_put(priv->dev);
1444err_pmdisable:
1445	if (pm_enable_call)
1446		pm_runtime_disable(dev);
1447err_free:
1448	list_del_init(&priv->peers_on_pdev);
1449	free_candev(ndev);
1450	return ret;
1451}
1452EXPORT_SYMBOL(ctucan_probe_common);
1453
1454MODULE_LICENSE("GPL");
1455MODULE_AUTHOR("Martin Jerabek <martin.jerabek01@gmail.com>");
1456MODULE_AUTHOR("Pavel Pisa <pisa@cmp.felk.cvut.cz>");
1457MODULE_AUTHOR("Ondrej Ille <ondrej.ille@gmail.com>");
1458MODULE_DESCRIPTION("CTU CAN FD interface");
1459