1// SPDX-License-Identifier: GPL-2.0
2
3/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
4 *
5 * File es581_4.c: Adds support to ETAS ES581.4.
6 *
7 * Copyright (c) 2019 Robert Bosch Engineering and Business Solutions. All rights reserved.
8 * Copyright (c) 2020 ETAS K.K.. All rights reserved.
9 * Copyright (c) 2020-2022 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
10 */
11
12#include <asm/unaligned.h>
13#include <linux/kernel.h>
14#include <linux/units.h>
15
16#include "es58x_core.h"
17#include "es581_4.h"
18
19/**
20 * es581_4_sizeof_rx_tx_msg() - Calculate the actual length of the
21 *	structure of a rx or tx message.
22 * @msg: message of variable length, must have a dlc field.
23 *
24 * Even if RTR frames have actually no payload, the ES58X devices
25 * still expect it. Must be a macro in order to accept several types
26 * (struct es581_4_tx_can_msg and struct es581_4_rx_can_msg) as an
27 * input.
28 *
29 * Return: length of the message.
30 */
31#define es581_4_sizeof_rx_tx_msg(msg)				\
32	offsetof(typeof(msg), data[can_cc_dlc2len((msg).dlc)])
33
34static u16 es581_4_get_msg_len(const union es58x_urb_cmd *urb_cmd)
35{
36	return get_unaligned_le16(&urb_cmd->es581_4_urb_cmd.msg_len);
37}
38
39static int es581_4_echo_msg(struct es58x_device *es58x_dev,
40			    const struct es581_4_urb_cmd *es581_4_urb_cmd)
41{
42	struct net_device *netdev;
43	const struct es581_4_bulk_echo_msg *bulk_echo_msg;
44	const struct es581_4_echo_msg *echo_msg;
45	u64 *tstamps = es58x_dev->timestamps;
46	u16 msg_len;
47	u32 first_packet_idx, packet_idx;
48	unsigned int dropped = 0;
49	int i, num_element, ret;
50
51	bulk_echo_msg = &es581_4_urb_cmd->bulk_echo_msg;
52	msg_len = get_unaligned_le16(&es581_4_urb_cmd->msg_len) -
53	    sizeof(bulk_echo_msg->channel_no);
54	num_element = es58x_msg_num_element(es58x_dev->dev,
55					    bulk_echo_msg->echo_msg, msg_len);
56	if (num_element <= 0)
57		return num_element;
58
59	ret = es58x_get_netdev(es58x_dev, bulk_echo_msg->channel_no,
60			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
61	if (ret)
62		return ret;
63
64	echo_msg = &bulk_echo_msg->echo_msg[0];
65	first_packet_idx = get_unaligned_le32(&echo_msg->packet_idx);
66	packet_idx = first_packet_idx;
67	for (i = 0; i < num_element; i++) {
68		u32 tmp_idx;
69
70		echo_msg = &bulk_echo_msg->echo_msg[i];
71		tmp_idx = get_unaligned_le32(&echo_msg->packet_idx);
72		if (tmp_idx == packet_idx - 1) {
73			if (net_ratelimit())
74				netdev_warn(netdev,
75					    "Received echo packet idx %u twice\n",
76					    packet_idx - 1);
77			dropped++;
78			continue;
79		}
80		if (tmp_idx != packet_idx) {
81			netdev_err(netdev, "Echo packet idx jumped from %u to %u\n",
82				   packet_idx - 1, echo_msg->packet_idx);
83			return -EBADMSG;
84		}
85
86		tstamps[i] = get_unaligned_le64(&echo_msg->timestamp);
87		packet_idx++;
88	}
89
90	netdev->stats.tx_dropped += dropped;
91	return es58x_can_get_echo_skb(netdev, first_packet_idx,
92				      tstamps, num_element - dropped);
93}
94
95static int es581_4_rx_can_msg(struct es58x_device *es58x_dev,
96			      const struct es581_4_urb_cmd *es581_4_urb_cmd,
97			      u16 msg_len)
98{
99	const struct device *dev = es58x_dev->dev;
100	struct net_device *netdev;
101	int pkts, num_element, channel_no, ret;
102
103	num_element = es58x_msg_num_element(dev, es581_4_urb_cmd->rx_can_msg,
104					    msg_len);
105	if (num_element <= 0)
106		return num_element;
107
108	channel_no = es581_4_urb_cmd->rx_can_msg[0].channel_no;
109	ret = es58x_get_netdev(es58x_dev, channel_no,
110			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
111	if (ret)
112		return ret;
113
114	if (!netif_running(netdev)) {
115		if (net_ratelimit())
116			netdev_info(netdev,
117				    "%s: %s is down, dropping %d rx packets\n",
118				    __func__, netdev->name, num_element);
119		netdev->stats.rx_dropped += num_element;
120		return 0;
121	}
122
123	for (pkts = 0; pkts < num_element; pkts++) {
124		const struct es581_4_rx_can_msg *rx_can_msg =
125		    &es581_4_urb_cmd->rx_can_msg[pkts];
126		u64 tstamp = get_unaligned_le64(&rx_can_msg->timestamp);
127		canid_t can_id = get_unaligned_le32(&rx_can_msg->can_id);
128
129		if (channel_no != rx_can_msg->channel_no)
130			return -EBADMSG;
131
132		ret = es58x_rx_can_msg(netdev, tstamp, rx_can_msg->data,
133				       can_id, rx_can_msg->flags,
134				       rx_can_msg->dlc);
135		if (ret)
136			break;
137	}
138
139	return ret;
140}
141
142static int es581_4_rx_err_msg(struct es58x_device *es58x_dev,
143			      const struct es581_4_rx_err_msg *rx_err_msg)
144{
145	struct net_device *netdev;
146	enum es58x_err error = get_unaligned_le32(&rx_err_msg->error);
147	int ret;
148
149	ret = es58x_get_netdev(es58x_dev, rx_err_msg->channel_no,
150			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
151	if (ret)
152		return ret;
153
154	return es58x_rx_err_msg(netdev, error, 0,
155				get_unaligned_le64(&rx_err_msg->timestamp));
156}
157
158static int es581_4_rx_event_msg(struct es58x_device *es58x_dev,
159				const struct es581_4_rx_event_msg *rx_event_msg)
160{
161	struct net_device *netdev;
162	enum es58x_event event = get_unaligned_le32(&rx_event_msg->event);
163	int ret;
164
165	ret = es58x_get_netdev(es58x_dev, rx_event_msg->channel_no,
166			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
167	if (ret)
168		return ret;
169
170	return es58x_rx_err_msg(netdev, 0, event,
171				get_unaligned_le64(&rx_event_msg->timestamp));
172}
173
174static int es581_4_rx_cmd_ret_u32(struct es58x_device *es58x_dev,
175				  const struct es581_4_urb_cmd *es581_4_urb_cmd,
176				  enum es58x_ret_type ret_type)
177{
178	struct net_device *netdev;
179	const struct es581_4_rx_cmd_ret *rx_cmd_ret;
180	u16 msg_len = get_unaligned_le16(&es581_4_urb_cmd->msg_len);
181	int ret;
182
183	ret = es58x_check_msg_len(es58x_dev->dev,
184				  es581_4_urb_cmd->rx_cmd_ret, msg_len);
185	if (ret)
186		return ret;
187
188	rx_cmd_ret = &es581_4_urb_cmd->rx_cmd_ret;
189
190	ret = es58x_get_netdev(es58x_dev, rx_cmd_ret->channel_no,
191			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
192	if (ret)
193		return ret;
194
195	return es58x_rx_cmd_ret_u32(netdev, ret_type,
196				    get_unaligned_le32(&rx_cmd_ret->rx_cmd_ret_le32));
197}
198
199static int es581_4_tx_ack_msg(struct es58x_device *es58x_dev,
200			      const struct es581_4_urb_cmd *es581_4_urb_cmd)
201{
202	struct net_device *netdev;
203	const struct es581_4_tx_ack_msg *tx_ack_msg;
204	u16 msg_len = get_unaligned_le16(&es581_4_urb_cmd->msg_len);
205	int ret;
206
207	tx_ack_msg = &es581_4_urb_cmd->tx_ack_msg;
208	ret = es58x_check_msg_len(es58x_dev->dev, *tx_ack_msg, msg_len);
209	if (ret)
210		return ret;
211
212	if (tx_ack_msg->rx_cmd_ret_u8 != ES58X_RET_U8_OK)
213		return es58x_rx_cmd_ret_u8(es58x_dev->dev,
214					   ES58X_RET_TYPE_TX_MSG,
215					   tx_ack_msg->rx_cmd_ret_u8);
216
217	ret = es58x_get_netdev(es58x_dev, tx_ack_msg->channel_no,
218			       ES581_4_CHANNEL_IDX_OFFSET, &netdev);
219	if (ret)
220		return ret;
221
222	return es58x_tx_ack_msg(netdev,
223				get_unaligned_le16(&tx_ack_msg->tx_free_entries),
224				ES58X_RET_U32_OK);
225}
226
227static int es581_4_dispatch_rx_cmd(struct es58x_device *es58x_dev,
228				   const struct es581_4_urb_cmd *es581_4_urb_cmd)
229{
230	const struct device *dev = es58x_dev->dev;
231	u16 msg_len = get_unaligned_le16(&es581_4_urb_cmd->msg_len);
232	enum es581_4_rx_type rx_type = es581_4_urb_cmd->rx_can_msg[0].rx_type;
233	int ret = 0;
234
235	switch (rx_type) {
236	case ES581_4_RX_TYPE_MESSAGE:
237		return es581_4_rx_can_msg(es58x_dev, es581_4_urb_cmd, msg_len);
238
239	case ES581_4_RX_TYPE_ERROR:
240		ret = es58x_check_msg_len(dev, es581_4_urb_cmd->rx_err_msg,
241					  msg_len);
242		if (ret < 0)
243			return ret;
244		return es581_4_rx_err_msg(es58x_dev,
245					  &es581_4_urb_cmd->rx_err_msg);
246
247	case ES581_4_RX_TYPE_EVENT:
248		ret = es58x_check_msg_len(dev, es581_4_urb_cmd->rx_event_msg,
249					  msg_len);
250		if (ret < 0)
251			return ret;
252		return es581_4_rx_event_msg(es58x_dev,
253					    &es581_4_urb_cmd->rx_event_msg);
254
255	default:
256		dev_err(dev, "%s: Unknown rx_type 0x%02X\n", __func__, rx_type);
257		return -EBADRQC;
258	}
259}
260
261static int es581_4_handle_urb_cmd(struct es58x_device *es58x_dev,
262				  const union es58x_urb_cmd *urb_cmd)
263{
264	const struct es581_4_urb_cmd *es581_4_urb_cmd;
265	struct device *dev = es58x_dev->dev;
266	u16 msg_len = es581_4_get_msg_len(urb_cmd);
267	int ret;
268
269	es581_4_urb_cmd = &urb_cmd->es581_4_urb_cmd;
270
271	if (es581_4_urb_cmd->cmd_type != ES581_4_CAN_COMMAND_TYPE) {
272		dev_err(dev, "%s: Unknown command type (0x%02X)\n",
273			__func__, es581_4_urb_cmd->cmd_type);
274		return -EBADRQC;
275	}
276
277	switch ((enum es581_4_cmd_id)es581_4_urb_cmd->cmd_id) {
278	case ES581_4_CMD_ID_SET_BITTIMING:
279		return es581_4_rx_cmd_ret_u32(es58x_dev, es581_4_urb_cmd,
280					      ES58X_RET_TYPE_SET_BITTIMING);
281
282	case ES581_4_CMD_ID_ENABLE_CHANNEL:
283		return es581_4_rx_cmd_ret_u32(es58x_dev, es581_4_urb_cmd,
284					      ES58X_RET_TYPE_ENABLE_CHANNEL);
285
286	case ES581_4_CMD_ID_TX_MSG:
287		return es581_4_tx_ack_msg(es58x_dev, es581_4_urb_cmd);
288
289	case ES581_4_CMD_ID_RX_MSG:
290		return es581_4_dispatch_rx_cmd(es58x_dev, es581_4_urb_cmd);
291
292	case ES581_4_CMD_ID_RESET_RX:
293		ret = es581_4_rx_cmd_ret_u32(es58x_dev, es581_4_urb_cmd,
294					     ES58X_RET_TYPE_RESET_RX);
295		return ret;
296
297	case ES581_4_CMD_ID_RESET_TX:
298		ret = es581_4_rx_cmd_ret_u32(es58x_dev, es581_4_urb_cmd,
299					     ES58X_RET_TYPE_RESET_TX);
300		return ret;
301
302	case ES581_4_CMD_ID_DISABLE_CHANNEL:
303		return es581_4_rx_cmd_ret_u32(es58x_dev, es581_4_urb_cmd,
304					      ES58X_RET_TYPE_DISABLE_CHANNEL);
305
306	case ES581_4_CMD_ID_TIMESTAMP:
307		ret = es58x_check_msg_len(dev, es581_4_urb_cmd->timestamp,
308					  msg_len);
309		if (ret < 0)
310			return ret;
311		es58x_rx_timestamp(es58x_dev,
312				   get_unaligned_le64(&es581_4_urb_cmd->timestamp));
313		return 0;
314
315	case ES581_4_CMD_ID_ECHO:
316		return es581_4_echo_msg(es58x_dev, es581_4_urb_cmd);
317
318	case ES581_4_CMD_ID_DEVICE_ERR:
319		ret = es58x_check_msg_len(dev, es581_4_urb_cmd->rx_cmd_ret_u8,
320					  msg_len);
321		if (ret)
322			return ret;
323		return es58x_rx_cmd_ret_u8(dev, ES58X_RET_TYPE_DEVICE_ERR,
324					   es581_4_urb_cmd->rx_cmd_ret_u8);
325
326	default:
327		dev_warn(dev, "%s: Unexpected command ID: 0x%02X\n",
328			 __func__, es581_4_urb_cmd->cmd_id);
329		return -EBADRQC;
330	}
331}
332
333static void es581_4_fill_urb_header(union es58x_urb_cmd *urb_cmd, u8 cmd_type,
334				    u8 cmd_id, u8 channel_idx, u16 msg_len)
335{
336	struct es581_4_urb_cmd *es581_4_urb_cmd = &urb_cmd->es581_4_urb_cmd;
337
338	es581_4_urb_cmd->SOF = cpu_to_le16(es581_4_param.tx_start_of_frame);
339	es581_4_urb_cmd->cmd_type = cmd_type;
340	es581_4_urb_cmd->cmd_id = cmd_id;
341	es581_4_urb_cmd->msg_len = cpu_to_le16(msg_len);
342}
343
344static int es581_4_tx_can_msg(struct es58x_priv *priv,
345			      const struct sk_buff *skb)
346{
347	struct es58x_device *es58x_dev = priv->es58x_dev;
348	union es58x_urb_cmd *urb_cmd = priv->tx_urb->transfer_buffer;
349	struct es581_4_urb_cmd *es581_4_urb_cmd = &urb_cmd->es581_4_urb_cmd;
350	struct can_frame *cf = (struct can_frame *)skb->data;
351	struct es581_4_tx_can_msg *tx_can_msg;
352	u16 msg_len;
353	int ret;
354
355	if (can_is_canfd_skb(skb))
356		return -EMSGSIZE;
357
358	if (priv->tx_can_msg_cnt == 0) {
359		msg_len = sizeof(es581_4_urb_cmd->bulk_tx_can_msg.num_can_msg);
360		es581_4_fill_urb_header(urb_cmd, ES581_4_CAN_COMMAND_TYPE,
361					ES581_4_CMD_ID_TX_MSG,
362					priv->channel_idx, msg_len);
363		es581_4_urb_cmd->bulk_tx_can_msg.num_can_msg = 0;
364	} else {
365		msg_len = es581_4_get_msg_len(urb_cmd);
366	}
367
368	ret = es58x_check_msg_max_len(es58x_dev->dev,
369				      es581_4_urb_cmd->bulk_tx_can_msg,
370				      msg_len + sizeof(*tx_can_msg));
371	if (ret)
372		return ret;
373
374	/* Fill message contents. */
375	tx_can_msg = (typeof(tx_can_msg))&es581_4_urb_cmd->raw_msg[msg_len];
376	put_unaligned_le32(es58x_get_raw_can_id(cf), &tx_can_msg->can_id);
377	put_unaligned_le32(priv->tx_head, &tx_can_msg->packet_idx);
378	put_unaligned_le16((u16)es58x_get_flags(skb), &tx_can_msg->flags);
379	tx_can_msg->channel_no = priv->channel_idx + ES581_4_CHANNEL_IDX_OFFSET;
380	tx_can_msg->dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
381
382	memcpy(tx_can_msg->data, cf->data, cf->len);
383
384	/* Calculate new sizes. */
385	es581_4_urb_cmd->bulk_tx_can_msg.num_can_msg++;
386	msg_len += es581_4_sizeof_rx_tx_msg(*tx_can_msg);
387	priv->tx_urb->transfer_buffer_length = es58x_get_urb_cmd_len(es58x_dev,
388								     msg_len);
389	es581_4_urb_cmd->msg_len = cpu_to_le16(msg_len);
390
391	return 0;
392}
393
394static int es581_4_set_bittiming(struct es58x_priv *priv)
395{
396	struct es581_4_tx_conf_msg tx_conf_msg = { 0 };
397	struct can_bittiming *bt = &priv->can.bittiming;
398
399	tx_conf_msg.bitrate = cpu_to_le32(bt->bitrate);
400	/* bt->sample_point is in tenth of percent. Convert it to percent. */
401	tx_conf_msg.sample_point = cpu_to_le32(bt->sample_point / 10U);
402	tx_conf_msg.samples_per_bit = cpu_to_le32(ES58X_SAMPLES_PER_BIT_ONE);
403	tx_conf_msg.bit_time = cpu_to_le32(can_bit_time(bt));
404	tx_conf_msg.sjw = cpu_to_le32(bt->sjw);
405	tx_conf_msg.sync_edge = cpu_to_le32(ES58X_SYNC_EDGE_SINGLE);
406	tx_conf_msg.physical_layer =
407	    cpu_to_le32(ES58X_PHYSICAL_LAYER_HIGH_SPEED);
408	tx_conf_msg.echo_mode = cpu_to_le32(ES58X_ECHO_ON);
409	tx_conf_msg.channel_no = priv->channel_idx + ES581_4_CHANNEL_IDX_OFFSET;
410
411	return es58x_send_msg(priv->es58x_dev, ES581_4_CAN_COMMAND_TYPE,
412			      ES581_4_CMD_ID_SET_BITTIMING, &tx_conf_msg,
413			      sizeof(tx_conf_msg), priv->channel_idx);
414}
415
416static int es581_4_enable_channel(struct es58x_priv *priv)
417{
418	int ret;
419	u8 msg = priv->channel_idx + ES581_4_CHANNEL_IDX_OFFSET;
420
421	ret = es581_4_set_bittiming(priv);
422	if (ret)
423		return ret;
424
425	return es58x_send_msg(priv->es58x_dev, ES581_4_CAN_COMMAND_TYPE,
426			      ES581_4_CMD_ID_ENABLE_CHANNEL, &msg, sizeof(msg),
427			      priv->channel_idx);
428}
429
430static int es581_4_disable_channel(struct es58x_priv *priv)
431{
432	u8 msg = priv->channel_idx + ES581_4_CHANNEL_IDX_OFFSET;
433
434	return es58x_send_msg(priv->es58x_dev, ES581_4_CAN_COMMAND_TYPE,
435			      ES581_4_CMD_ID_DISABLE_CHANNEL, &msg, sizeof(msg),
436			      priv->channel_idx);
437}
438
439static int es581_4_reset_device(struct es58x_device *es58x_dev)
440{
441	return es58x_send_msg(es58x_dev, ES581_4_CAN_COMMAND_TYPE,
442			      ES581_4_CMD_ID_RESET_DEVICE,
443			      ES58X_EMPTY_MSG, 0, ES58X_CHANNEL_IDX_NA);
444}
445
446static int es581_4_get_timestamp(struct es58x_device *es58x_dev)
447{
448	return es58x_send_msg(es58x_dev, ES581_4_CAN_COMMAND_TYPE,
449			      ES581_4_CMD_ID_TIMESTAMP,
450			      ES58X_EMPTY_MSG, 0, ES58X_CHANNEL_IDX_NA);
451}
452
453/* Nominal bittiming constants for ES581.4 as specified in the
454 * microcontroller datasheet: "Stellaris(R) LM3S5B91 Microcontroller"
455 * table 17-4 "CAN Protocol Ranges" from Texas Instruments.
456 */
457static const struct can_bittiming_const es581_4_bittiming_const = {
458	.name = "ES581.4",
459	.tseg1_min = 1,
460	.tseg1_max = 8,
461	.tseg2_min = 1,
462	.tseg2_max = 8,
463	.sjw_max = 4,
464	.brp_min = 1,
465	.brp_max = 128,
466	.brp_inc = 1
467};
468
469const struct es58x_parameters es581_4_param = {
470	.bittiming_const = &es581_4_bittiming_const,
471	.data_bittiming_const = NULL,
472	.tdc_const = NULL,
473	.bitrate_max = 1 * MEGA /* BPS */,
474	.clock = {.freq = 50 * MEGA /* Hz */},
475	.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC,
476	.tx_start_of_frame = 0xAFAF,
477	.rx_start_of_frame = 0xFAFA,
478	.tx_urb_cmd_max_len = ES581_4_TX_URB_CMD_MAX_LEN,
479	.rx_urb_cmd_max_len = ES581_4_RX_URB_CMD_MAX_LEN,
480	/* Size of internal device TX queue is 330.
481	 *
482	 * However, we witnessed some ES58X_ERR_PROT_CRC errors from
483	 * the device and thus, echo_skb_max was lowered to the
484	 * empirical value of 75 which seems stable and then rounded
485	 * down to become a power of two.
486	 *
487	 * Root cause of those ES58X_ERR_PROT_CRC errors is still
488	 * unclear.
489	 */
490	.fifo_mask = 63, /* echo_skb_max = 64 */
491	.dql_min_limit = CAN_FRAME_LEN_MAX * 50, /* Empirical value. */
492	.tx_bulk_max = ES581_4_TX_BULK_MAX,
493	.urb_cmd_header_len = ES581_4_URB_CMD_HEADER_LEN,
494	.rx_urb_max = ES58X_RX_URBS_MAX,
495	.tx_urb_max = ES58X_TX_URBS_MAX
496};
497
498const struct es58x_operators es581_4_ops = {
499	.get_msg_len = es581_4_get_msg_len,
500	.handle_urb_cmd = es581_4_handle_urb_cmd,
501	.fill_urb_header = es581_4_fill_urb_header,
502	.tx_can_msg = es581_4_tx_can_msg,
503	.enable_channel = es581_4_enable_channel,
504	.disable_channel = es581_4_disable_channel,
505	.reset_device = es581_4_reset_device,
506	.get_timestamp = es581_4_get_timestamp
507};
508