nct6694_canfd.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* Nuvoton NCT6694 Socket CANfd driver based on USB interface.
  3 *
  4 * Copyright (C) 2025 Nuvoton Technology Corp.
  5 */
  6
  7#include <linux/bitfield.h>
  8#include <linux/can/dev.h>
  9#include <linux/can/rx-offload.h>
 10#include <linux/ethtool.h>
 11#include <linux/idr.h>
 12#include <linux/irqdomain.h>
 13#include <linux/kernel.h>
 14#include <linux/mfd/nct6694.h>
 15#include <linux/module.h>
 16#include <linux/netdevice.h>
 17#include <linux/platform_device.h>
 18
 19#define DEVICE_NAME "nct6694-canfd"
 20
 21/* USB command module type for NCT6694 CANfd controller.
 22 * This defines the module type used for communication with the NCT6694
 23 * CANfd controller over the USB interface.
 24 */
 25#define NCT6694_CANFD_MOD			0x05
 26
 27/* Command 00h - CAN Setting and Initialization */
 28#define NCT6694_CANFD_SETTING			0x00
 29#define NCT6694_CANFD_SETTING_ACTIVE_CTRL1	BIT(0)
 30#define NCT6694_CANFD_SETTING_ACTIVE_CTRL2	BIT(1)
 31#define NCT6694_CANFD_SETTING_ACTIVE_NBTP_DBTP	BIT(2)
 32#define NCT6694_CANFD_SETTING_CTRL1_MON		BIT(0)
 33#define NCT6694_CANFD_SETTING_CTRL1_NISO	BIT(1)
 34#define NCT6694_CANFD_SETTING_CTRL1_LBCK	BIT(2)
 35#define NCT6694_CANFD_SETTING_NBTP_NTSEG2	GENMASK(6, 0)
 36#define NCT6694_CANFD_SETTING_NBTP_NTSEG1	GENMASK(15, 8)
 37#define NCT6694_CANFD_SETTING_NBTP_NBRP		GENMASK(24, 16)
 38#define NCT6694_CANFD_SETTING_NBTP_NSJW		GENMASK(31, 25)
 39#define NCT6694_CANFD_SETTING_DBTP_DSJW		GENMASK(3, 0)
 40#define NCT6694_CANFD_SETTING_DBTP_DTSEG2	GENMASK(7, 4)
 41#define NCT6694_CANFD_SETTING_DBTP_DTSEG1	GENMASK(12, 8)
 42#define NCT6694_CANFD_SETTING_DBTP_DBRP		GENMASK(20, 16)
 43#define NCT6694_CANFD_SETTING_DBTP_TDC		BIT(23)
 44
 45/* Command 01h - CAN Information */
 46#define NCT6694_CANFD_INFORMATION		0x01
 47#define NCT6694_CANFD_INFORMATION_SEL		0x00
 48
 49/* Command 02h - CAN Event */
 50#define NCT6694_CANFD_EVENT			0x02
 51#define NCT6694_CANFD_EVENT_SEL(idx, mask)	\
 52	((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
 53
 54#define NCT6694_CANFD_EVENT_MASK		GENMASK(5, 0)
 55#define NCT6694_CANFD_EVT_TX_FIFO_EMPTY		BIT(7)	/* Read-clear */
 56#define NCT6694_CANFD_EVT_RX_DATA_LOST		BIT(5)	/* Read-clear */
 57#define NCT6694_CANFD_EVT_RX_DATA_IN		BIT(7)	/* Read-clear */
 58
 59/* Command 10h - CAN Deliver */
 60#define NCT6694_CANFD_DELIVER			0x10
 61#define NCT6694_CANFD_DELIVER_SEL(buf_cnt)	\
 62	((buf_cnt) & 0xFF)
 63
 64/* Command 11h - CAN Receive */
 65#define NCT6694_CANFD_RECEIVE			0x11
 66#define NCT6694_CANFD_RECEIVE_SEL(idx, buf_cnt)	\
 67	((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
 68
 69#define NCT6694_CANFD_FRAME_TAG(idx)		(0xC0 | (idx))
 70#define NCT6694_CANFD_FRAME_FLAG_EFF		BIT(0)
 71#define NCT6694_CANFD_FRAME_FLAG_RTR		BIT(1)
 72#define NCT6694_CANFD_FRAME_FLAG_FD		BIT(2)
 73#define NCT6694_CANFD_FRAME_FLAG_BRS		BIT(3)
 74#define NCT6694_CANFD_FRAME_FLAG_ERR		BIT(4)
 75
 76#define NCT6694_NAPI_WEIGHT			32
 77
 78enum nct6694_event_err {
 79	NCT6694_CANFD_EVT_ERR_NO_ERROR = 0,
 80	NCT6694_CANFD_EVT_ERR_CRC_ERROR,
 81	NCT6694_CANFD_EVT_ERR_STUFF_ERROR,
 82	NCT6694_CANFD_EVT_ERR_ACK_ERROR,
 83	NCT6694_CANFD_EVT_ERR_FORM_ERROR,
 84	NCT6694_CANFD_EVT_ERR_BIT_ERROR,
 85	NCT6694_CANFD_EVT_ERR_TIMEOUT_ERROR,
 86	NCT6694_CANFD_EVT_ERR_UNKNOWN_ERROR,
 87};
 88
 89enum nct6694_event_status {
 90	NCT6694_CANFD_EVT_STS_ERROR_ACTIVE = 0,
 91	NCT6694_CANFD_EVT_STS_ERROR_PASSIVE,
 92	NCT6694_CANFD_EVT_STS_BUS_OFF,
 93	NCT6694_CANFD_EVT_STS_WARNING,
 94};
 95
 96struct __packed nct6694_canfd_setting {
 97	__le32 nbr;
 98	__le32 dbr;
 99	u8 active;
100	u8 reserved[3];
101	__le16 ctrl1;
102	__le16 ctrl2;
103	__le32 nbtp;
104	__le32 dbtp;
105};
106
107struct __packed nct6694_canfd_information {
108	u8 tx_fifo_cnt;
109	u8 rx_fifo_cnt;
110	u8 reserved[2];
111	__le32 can_clk;
112};
113
114struct __packed nct6694_canfd_event {
115	u8 err;
116	u8 status;
117	u8 tx_evt;
118	u8 rx_evt;
119	u8 rec;
120	u8 tec;
121	u8 reserved[2];
122};
123
124struct __packed nct6694_canfd_frame {
125	u8 tag;
126	u8 flag;
127	u8 reserved;
128	u8 length;
129	__le32 id;
130	u8 data[CANFD_MAX_DLEN];
131};
132
133struct nct6694_canfd_priv {
134	struct can_priv can;	/* must be the first member */
135	struct can_rx_offload offload;
136	struct net_device *ndev;
137	struct nct6694 *nct6694;
138	struct workqueue_struct *wq;
139	struct work_struct tx_work;
140	struct nct6694_canfd_frame tx;
141	struct nct6694_canfd_frame rx;
142	struct nct6694_canfd_event event[2];
143	struct can_berr_counter bec;
144};
145
146static inline struct nct6694_canfd_priv *rx_offload_to_priv(struct can_rx_offload *offload)
147{
148	return container_of(offload, struct nct6694_canfd_priv, offload);
149}
150
151static const struct can_bittiming_const nct6694_canfd_bittiming_nominal_const = {
152	.name = DEVICE_NAME,
153	.tseg1_min = 1,
154	.tseg1_max = 256,
155	.tseg2_min = 1,
156	.tseg2_max = 128,
157	.sjw_max = 128,
158	.brp_min = 1,
159	.brp_max = 512,
160	.brp_inc = 1,
161};
162
163static const struct can_bittiming_const nct6694_canfd_bittiming_data_const = {
164	.name = DEVICE_NAME,
165	.tseg1_min = 1,
166	.tseg1_max = 32,
167	.tseg2_min = 1,
168	.tseg2_max = 16,
169	.sjw_max = 16,
170	.brp_min = 1,
171	.brp_max = 32,
172	.brp_inc = 1,
173};
174
175static void nct6694_canfd_rx_offload(struct can_rx_offload *offload,
176				     struct sk_buff *skb)
177{
178	struct nct6694_canfd_priv *priv = rx_offload_to_priv(offload);
179	int ret;
180
181	ret = can_rx_offload_queue_tail(offload, skb);
182	if (ret)
183		priv->ndev->stats.rx_fifo_errors++;
184}
185
186static void nct6694_canfd_handle_lost_msg(struct net_device *ndev)
187{
188	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
189	struct net_device_stats *stats = &ndev->stats;
190	struct can_frame *cf;
191	struct sk_buff *skb;
192
193	netdev_dbg(ndev, "RX FIFO overflow, message(s) lost.\n");
194
195	stats->rx_errors++;
196	stats->rx_over_errors++;
197
198	skb = alloc_can_err_skb(ndev, &cf);
199	if (!skb)
200		return;
201
202	cf->can_id |= CAN_ERR_CRTL;
203	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
204
205	nct6694_canfd_rx_offload(&priv->offload, skb);
206}
207
208static void nct6694_canfd_handle_rx(struct net_device *ndev, u8 rx_evt)
209{
210	struct net_device_stats *stats = &ndev->stats;
211	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
212	struct nct6694_canfd_frame *frame = &priv->rx;
213	const struct nct6694_cmd_header cmd_hd = {
214		.mod = NCT6694_CANFD_MOD,
215		.cmd = NCT6694_CANFD_RECEIVE,
216		.sel = NCT6694_CANFD_RECEIVE_SEL(ndev->dev_port, 1),
217		.len = cpu_to_le16(sizeof(*frame))
218	};
219	struct sk_buff *skb;
220	int ret;
221
222	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, frame);
223	if (ret)
224		return;
225
226	if (frame->flag & NCT6694_CANFD_FRAME_FLAG_FD) {
227		struct canfd_frame *cfd;
228
229		skb = alloc_canfd_skb(priv->ndev, &cfd);
230		if (!skb) {
231			stats->rx_dropped++;
232			return;
233		}
234
235		cfd->can_id = le32_to_cpu(frame->id);
236		cfd->len = canfd_sanitize_len(frame->length);
237		if (frame->flag & NCT6694_CANFD_FRAME_FLAG_EFF)
238			cfd->can_id |= CAN_EFF_FLAG;
239		if (frame->flag & NCT6694_CANFD_FRAME_FLAG_BRS)
240			cfd->flags |= CANFD_BRS;
241		if (frame->flag & NCT6694_CANFD_FRAME_FLAG_ERR)
242			cfd->flags |= CANFD_ESI;
243
244		memcpy(cfd->data, frame->data, cfd->len);
245	} else {
246		struct can_frame *cf;
247
248		skb = alloc_can_skb(priv->ndev, &cf);
249		if (!skb) {
250			stats->rx_dropped++;
251			return;
252		}
253
254		cf->can_id = le32_to_cpu(frame->id);
255		cf->len = can_cc_dlc2len(frame->length);
256		if (frame->flag & NCT6694_CANFD_FRAME_FLAG_EFF)
257			cf->can_id |= CAN_EFF_FLAG;
258
259		if (frame->flag & NCT6694_CANFD_FRAME_FLAG_RTR)
260			cf->can_id |= CAN_RTR_FLAG;
261		else
262			memcpy(cf->data, frame->data, cf->len);
263	}
264
265	nct6694_canfd_rx_offload(&priv->offload, skb);
266}
267
268static int nct6694_canfd_get_berr_counter(const struct net_device *ndev,
269					  struct can_berr_counter *bec)
270{
271	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
272
273	*bec = priv->bec;
274
275	return 0;
276}
277
278static void nct6694_canfd_handle_state_change(struct net_device *ndev, u8 status)
279{
280	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
281	enum can_state new_state, rx_state, tx_state;
282	struct can_berr_counter bec;
283	struct can_frame *cf;
284	struct sk_buff *skb;
285
286	nct6694_canfd_get_berr_counter(ndev, &bec);
287	can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);
288
289	new_state = max(tx_state, rx_state);
290
291	/* state hasn't changed */
292	if (new_state == priv->can.state)
293		return;
294
295	skb = alloc_can_err_skb(ndev, &cf);
296
297	can_change_state(ndev, cf, tx_state, rx_state);
298
299	if (new_state == CAN_STATE_BUS_OFF) {
300		can_bus_off(ndev);
301	} else if (cf) {
302		cf->can_id |= CAN_ERR_CNT;
303		cf->data[6] = bec.txerr;
304		cf->data[7] = bec.rxerr;
305	}
306
307	if (skb)
308		nct6694_canfd_rx_offload(&priv->offload, skb);
309}
310
311static void nct6694_canfd_handle_bus_err(struct net_device *ndev, u8 bus_err)
312{
313	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
314	struct can_frame *cf;
315	struct sk_buff *skb;
316
317	priv->can.can_stats.bus_error++;
318
319	skb = alloc_can_err_skb(ndev, &cf);
320	if (cf)
321		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
322
323	switch (bus_err) {
324	case NCT6694_CANFD_EVT_ERR_CRC_ERROR:
325		netdev_dbg(ndev, "CRC error\n");
326		ndev->stats.rx_errors++;
327		if (cf)
328			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
329		break;
330
331	case NCT6694_CANFD_EVT_ERR_STUFF_ERROR:
332		netdev_dbg(ndev, "Stuff error\n");
333		ndev->stats.rx_errors++;
334		if (cf)
335			cf->data[2] |= CAN_ERR_PROT_STUFF;
336		break;
337
338	case NCT6694_CANFD_EVT_ERR_ACK_ERROR:
339		netdev_dbg(ndev, "Ack error\n");
340		ndev->stats.tx_errors++;
341		if (cf) {
342			cf->can_id |= CAN_ERR_ACK;
343			cf->data[2] |= CAN_ERR_PROT_TX;
344		}
345		break;
346
347	case NCT6694_CANFD_EVT_ERR_FORM_ERROR:
348		netdev_dbg(ndev, "Form error\n");
349		ndev->stats.rx_errors++;
350		if (cf)
351			cf->data[2] |= CAN_ERR_PROT_FORM;
352		break;
353
354	case NCT6694_CANFD_EVT_ERR_BIT_ERROR:
355		netdev_dbg(ndev, "Bit error\n");
356		ndev->stats.tx_errors++;
357		if (cf)
358			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
359		break;
360
361	default:
362		break;
363	}
364
365	if (skb)
366		nct6694_canfd_rx_offload(&priv->offload, skb);
367}
368
369static void nct6694_canfd_handle_tx(struct net_device *ndev)
370{
371	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
372	struct net_device_stats *stats = &ndev->stats;
373
374	stats->tx_bytes += can_rx_offload_get_echo_skb_queue_tail(&priv->offload,
375								  0, NULL);
376	stats->tx_packets++;
377	netif_wake_queue(ndev);
378}
379
380static irqreturn_t nct6694_canfd_irq(int irq, void *data)
381{
382	struct net_device *ndev = data;
383	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
384	struct nct6694_canfd_event *event = &priv->event[ndev->dev_port];
385	const struct nct6694_cmd_header cmd_hd = {
386		.mod = NCT6694_CANFD_MOD,
387		.cmd = NCT6694_CANFD_EVENT,
388		.sel = NCT6694_CANFD_EVENT_SEL(ndev->dev_port, NCT6694_CANFD_EVENT_MASK),
389		.len = cpu_to_le16(sizeof(priv->event))
390	};
391	irqreturn_t handled = IRQ_NONE;
392	int ret;
393
394	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, priv->event);
395	if (ret < 0)
396		return handled;
397
398	if (event->rx_evt & NCT6694_CANFD_EVT_RX_DATA_IN) {
399		nct6694_canfd_handle_rx(ndev, event->rx_evt);
400		handled = IRQ_HANDLED;
401	}
402
403	if (event->rx_evt & NCT6694_CANFD_EVT_RX_DATA_LOST) {
404		nct6694_canfd_handle_lost_msg(ndev);
405		handled = IRQ_HANDLED;
406	}
407
408	if (event->status) {
409		nct6694_canfd_handle_state_change(ndev, event->status);
410		handled = IRQ_HANDLED;
411	}
412
413	if (event->err != NCT6694_CANFD_EVT_ERR_NO_ERROR) {
414		if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
415			nct6694_canfd_handle_bus_err(ndev, event->err);
416		handled = IRQ_HANDLED;
417	}
418
419	if (event->tx_evt & NCT6694_CANFD_EVT_TX_FIFO_EMPTY) {
420		nct6694_canfd_handle_tx(ndev);
421		handled = IRQ_HANDLED;
422	}
423
424	if (handled)
425		can_rx_offload_threaded_irq_finish(&priv->offload);
426
427	priv->bec.rxerr = event->rec;
428	priv->bec.txerr = event->tec;
429
430	return handled;
431}
432
433static void nct6694_canfd_tx_work(struct work_struct *work)
434{
435	struct nct6694_canfd_priv *priv = container_of(work,
436						       struct nct6694_canfd_priv,
437						       tx_work);
438	struct nct6694_canfd_frame *frame = &priv->tx;
439	struct net_device *ndev = priv->ndev;
440	struct net_device_stats *stats = &ndev->stats;
441	struct sk_buff *skb = priv->can.echo_skb[0];
442	static const struct nct6694_cmd_header cmd_hd = {
443		.mod = NCT6694_CANFD_MOD,
444		.cmd = NCT6694_CANFD_DELIVER,
445		.sel = NCT6694_CANFD_DELIVER_SEL(1),
446		.len = cpu_to_le16(sizeof(*frame))
447	};
448	u32 txid;
449	int err;
450
451	memset(frame, 0, sizeof(*frame));
452
453	frame->tag = NCT6694_CANFD_FRAME_TAG(ndev->dev_port);
454
455	if (can_is_canfd_skb(skb)) {
456		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
457
458		if (cfd->flags & CANFD_BRS)
459			frame->flag |= NCT6694_CANFD_FRAME_FLAG_BRS;
460
461		if (cfd->can_id & CAN_EFF_FLAG) {
462			txid = cfd->can_id & CAN_EFF_MASK;
463			frame->flag |= NCT6694_CANFD_FRAME_FLAG_EFF;
464		} else {
465			txid = cfd->can_id & CAN_SFF_MASK;
466		}
467		frame->flag |= NCT6694_CANFD_FRAME_FLAG_FD;
468		frame->id = cpu_to_le32(txid);
469		frame->length = canfd_sanitize_len(cfd->len);
470
471		memcpy(frame->data, cfd->data, frame->length);
472	} else {
473		struct can_frame *cf = (struct can_frame *)skb->data;
474
475		if (cf->can_id & CAN_EFF_FLAG) {
476			txid = cf->can_id & CAN_EFF_MASK;
477			frame->flag |= NCT6694_CANFD_FRAME_FLAG_EFF;
478		} else {
479			txid = cf->can_id & CAN_SFF_MASK;
480		}
481
482		if (cf->can_id & CAN_RTR_FLAG)
483			frame->flag |= NCT6694_CANFD_FRAME_FLAG_RTR;
484		else
485			memcpy(frame->data, cf->data, cf->len);
486
487		frame->id = cpu_to_le32(txid);
488		frame->length = cf->len;
489	}
490
491	err = nct6694_write_msg(priv->nct6694, &cmd_hd, frame);
492	if (err) {
493		can_free_echo_skb(ndev, 0, NULL);
494		stats->tx_dropped++;
495		stats->tx_errors++;
496		netif_wake_queue(ndev);
497	}
498}
499
500static netdev_tx_t nct6694_canfd_start_xmit(struct sk_buff *skb,
501					    struct net_device *ndev)
502{
503	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
504
505	if (can_dev_dropped_skb(ndev, skb))
506		return NETDEV_TX_OK;
507
508	netif_stop_queue(ndev);
509	can_put_echo_skb(skb, ndev, 0, 0);
510	queue_work(priv->wq, &priv->tx_work);
511
512	return NETDEV_TX_OK;
513}
514
515static int nct6694_canfd_start(struct net_device *ndev)
516{
517	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
518	const struct can_bittiming *n_bt = &priv->can.bittiming;
519	const struct can_bittiming *d_bt = &priv->can.fd.data_bittiming;
520	struct nct6694_canfd_setting *setting __free(kfree) = NULL;
521	const struct nct6694_cmd_header cmd_hd = {
522		.mod = NCT6694_CANFD_MOD,
523		.cmd = NCT6694_CANFD_SETTING,
524		.sel = ndev->dev_port,
525		.len = cpu_to_le16(sizeof(*setting))
526	};
527	u32 en_tdc;
528	int ret;
529
530	setting = kzalloc(sizeof(*setting), GFP_KERNEL);
531	if (!setting)
532		return -ENOMEM;
533
534	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
535		setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_MON);
536
537	if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
538		setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_NISO);
539
540	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
541		setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_LBCK);
542
543	/* Disable clock divider */
544	setting->ctrl2 = 0;
545
546	setting->nbtp = cpu_to_le32(FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NSJW,
547					       n_bt->sjw - 1) |
548				    FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NBRP,
549					       n_bt->brp - 1) |
550				    FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NTSEG2,
551					       n_bt->phase_seg2 - 1) |
552				    FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NTSEG1,
553					       n_bt->prop_seg + n_bt->phase_seg1 - 1));
554
555	if (d_bt->brp <= 2)
556		en_tdc = NCT6694_CANFD_SETTING_DBTP_TDC;
557	else
558		en_tdc = 0;
559
560	setting->dbtp = cpu_to_le32(FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DSJW,
561					       d_bt->sjw - 1) |
562				    FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DBRP,
563					       d_bt->brp - 1) |
564				    FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DTSEG2,
565					       d_bt->phase_seg2 - 1) |
566				    FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DTSEG1,
567					       d_bt->prop_seg + d_bt->phase_seg1 - 1) |
568				    en_tdc);
569
570	setting->active = NCT6694_CANFD_SETTING_ACTIVE_CTRL1 |
571			  NCT6694_CANFD_SETTING_ACTIVE_CTRL2 |
572			  NCT6694_CANFD_SETTING_ACTIVE_NBTP_DBTP;
573
574	ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
575	if (ret)
576		return ret;
577
578	priv->can.state = CAN_STATE_ERROR_ACTIVE;
579
580	return 0;
581}
582
583static void nct6694_canfd_stop(struct net_device *ndev)
584{
585	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
586	struct nct6694_canfd_setting *setting __free(kfree) = NULL;
587	const struct nct6694_cmd_header cmd_hd = {
588		.mod = NCT6694_CANFD_MOD,
589		.cmd = NCT6694_CANFD_SETTING,
590		.sel = ndev->dev_port,
591		.len = cpu_to_le16(sizeof(*setting))
592	};
593
594	/* The NCT6694 cannot be stopped. To ensure safe operation and avoid
595	 * interference, the control mode is set to Listen-Only mode. This
596	 * mode allows the device to monitor bus activity without actively
597	 * participating in communication.
598	 */
599	setting = kzalloc(sizeof(*setting), GFP_KERNEL);
600	if (!setting)
601		return;
602
603	nct6694_read_msg(priv->nct6694, &cmd_hd, setting);
604	setting->ctrl1 = cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_MON);
605	setting->active = NCT6694_CANFD_SETTING_ACTIVE_CTRL1;
606	nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
607
608	priv->can.state = CAN_STATE_STOPPED;
609}
610
611static int nct6694_canfd_close(struct net_device *ndev)
612{
613	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
614
615	netif_stop_queue(ndev);
616	nct6694_canfd_stop(ndev);
617	destroy_workqueue(priv->wq);
618	free_irq(ndev->irq, ndev);
619	can_rx_offload_disable(&priv->offload);
620	close_candev(ndev);
621	return 0;
622}
623
624static int nct6694_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
625{
626	int ret;
627
628	switch (mode) {
629	case CAN_MODE_START:
630		ret = nct6694_canfd_start(ndev);
631		if (ret)
632			return ret;
633
634		netif_wake_queue(ndev);
635		break;
636
637	default:
638		return -EOPNOTSUPP;
639	}
640
641	return ret;
642}
643
644static int nct6694_canfd_open(struct net_device *ndev)
645{
646	struct nct6694_canfd_priv *priv = netdev_priv(ndev);
647	int ret;
648
649	ret = open_candev(ndev);
650	if (ret)
651		return ret;
652
653	can_rx_offload_enable(&priv->offload);
654
655	ret = request_threaded_irq(ndev->irq, NULL,
656				   nct6694_canfd_irq, IRQF_ONESHOT,
657				   "nct6694_canfd", ndev);
658	if (ret) {
659		netdev_err(ndev, "Failed to request IRQ\n");
660		goto can_rx_offload_disable;
661	}
662
663	priv->wq = alloc_ordered_workqueue("%s-nct6694_wq",
664					   WQ_FREEZABLE | WQ_MEM_RECLAIM,
665					   ndev->name);
666	if (!priv->wq) {
667		ret = -ENOMEM;
668		goto free_irq;
669	}
670
671	ret = nct6694_canfd_start(ndev);
672	if (ret)
673		goto destroy_wq;
674
675	netif_start_queue(ndev);
676
677	return 0;
678
679destroy_wq:
680	destroy_workqueue(priv->wq);
681free_irq:
682	free_irq(ndev->irq, ndev);
683can_rx_offload_disable:
684	can_rx_offload_disable(&priv->offload);
685	close_candev(ndev);
686	return ret;
687}
688
689static const struct net_device_ops nct6694_canfd_netdev_ops = {
690	.ndo_open = nct6694_canfd_open,
691	.ndo_stop = nct6694_canfd_close,
692	.ndo_start_xmit = nct6694_canfd_start_xmit,
693};
694
695static const struct ethtool_ops nct6694_canfd_ethtool_ops = {
696	.get_ts_info = ethtool_op_get_ts_info,
697};
698
699static int nct6694_canfd_get_clock(struct nct6694_canfd_priv *priv)
700{
701	struct nct6694_canfd_information *info __free(kfree) = NULL;
702	static const struct nct6694_cmd_header cmd_hd = {
703		.mod = NCT6694_CANFD_MOD,
704		.cmd = NCT6694_CANFD_INFORMATION,
705		.sel = NCT6694_CANFD_INFORMATION_SEL,
706		.len = cpu_to_le16(sizeof(*info))
707	};
708	int ret;
709
710	info = kzalloc(sizeof(*info), GFP_KERNEL);
711	if (!info)
712		return -ENOMEM;
713
714	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, info);
715	if (ret)
716		return ret;
717
718	return le32_to_cpu(info->can_clk);
719}
720
721static int nct6694_canfd_probe(struct platform_device *pdev)
722{
723	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
724	struct nct6694_canfd_priv *priv;
725	struct net_device *ndev;
726	int port, irq, ret, can_clk;
727
728	port = ida_alloc(&nct6694->canfd_ida, GFP_KERNEL);
729	if (port < 0)
730		return port;
731
732	irq = irq_create_mapping(nct6694->domain,
733				 NCT6694_IRQ_CAN0 + port);
734	if (!irq) {
735		ret = -EINVAL;
736		goto free_ida;
737	}
738
739	ndev = alloc_candev(sizeof(struct nct6694_canfd_priv), 1);
740	if (!ndev) {
741		ret = -ENOMEM;
742		goto dispose_irq;
743	}
744
745	ndev->irq = irq;
746	ndev->flags |= IFF_ECHO;
747	ndev->dev_port = port;
748	ndev->netdev_ops = &nct6694_canfd_netdev_ops;
749	ndev->ethtool_ops = &nct6694_canfd_ethtool_ops;
750
751	priv = netdev_priv(ndev);
752	priv->nct6694 = nct6694;
753	priv->ndev = ndev;
754
755	can_clk = nct6694_canfd_get_clock(priv);
756	if (can_clk < 0) {
757		ret = dev_err_probe(&pdev->dev, can_clk,
758				    "Failed to get clock\n");
759		goto free_candev;
760	}
761
762	INIT_WORK(&priv->tx_work, nct6694_canfd_tx_work);
763
764	priv->can.clock.freq = can_clk;
765	priv->can.bittiming_const = &nct6694_canfd_bittiming_nominal_const;
766	priv->can.fd.data_bittiming_const = &nct6694_canfd_bittiming_data_const;
767	priv->can.do_set_mode = nct6694_canfd_set_mode;
768	priv->can.do_get_berr_counter = nct6694_canfd_get_berr_counter;
769	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
770		CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
771		CAN_CTRLMODE_FD_NON_ISO;
772
773	ret = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
774	if (ret)
775		goto free_candev;
776
777	ret = can_rx_offload_add_manual(ndev, &priv->offload,
778					NCT6694_NAPI_WEIGHT);
779	if (ret) {
780		dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
781		goto free_candev;
782	}
783
784	platform_set_drvdata(pdev, priv);
785	SET_NETDEV_DEV(priv->ndev, &pdev->dev);
786
787	ret = register_candev(priv->ndev);
788	if (ret)
789		goto rx_offload_del;
790
791	return 0;
792
793rx_offload_del:
794	can_rx_offload_del(&priv->offload);
795free_candev:
796	free_candev(ndev);
797dispose_irq:
798	irq_dispose_mapping(irq);
799free_ida:
800	ida_free(&nct6694->canfd_ida, port);
801	return ret;
802}
803
804static void nct6694_canfd_remove(struct platform_device *pdev)
805{
806	struct nct6694_canfd_priv *priv = platform_get_drvdata(pdev);
807	struct nct6694 *nct6694 = priv->nct6694;
808	struct net_device *ndev = priv->ndev;
809	int port = ndev->dev_port;
810	int irq = ndev->irq;
811
812	unregister_candev(ndev);
813	can_rx_offload_del(&priv->offload);
814	free_candev(ndev);
815	irq_dispose_mapping(irq);
816	ida_free(&nct6694->canfd_ida, port);
817}
818
819static struct platform_driver nct6694_canfd_driver = {
820	.driver = {
821		.name	= DEVICE_NAME,
822	},
823	.probe		= nct6694_canfd_probe,
824	.remove		= nct6694_canfd_remove,
825};
826
827module_platform_driver(nct6694_canfd_driver);
828
829MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
830MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
831MODULE_LICENSE("GPL");