drivers/net/can/usb/etas_es58x/es58x_fd.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0

 /* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
  *
  * File es58x_fd.c: Adds support to ETAS ES582.1 and ES584.1 (naming
  * convention: we use the term "ES58X FD" when referring to those two
  * variants together).
  *
  * Copyright (c) 2019 Robert Bosch Engineering and Business Solutions. All rights reserved.
  * Copyright (c) 2020 ETAS K.K.. All rights reserved.
  * Copyright (c) 2020, 2021 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
  */

 #include <linux/kernel.h>
 #include <asm/unaligned.h>

 #include "es58x_core.h"
 #include "es58x_fd.h"

 /**
  * es58x_fd_sizeof_rx_tx_msg() - Calculate the actual length of the
  *	structure of a rx or tx message.
  * @msg: message of variable length, must have a dlc and a len fields.
  *
  * Even if RTR frames have actually no payload, the ES58X devices
  * still expect it. Must be a macro in order to accept several types
  * (struct es58x_fd_tx_can_msg and struct es58x_fd_rx_can_msg) as an
  * input.
  *
  * Return: length of the message.
  */
 #define es58x_fd_sizeof_rx_tx_msg(msg)					\
 ({									\
 	typeof(msg) __msg = (msg);					\
 	size_t __msg_len;						\
 									\
 	if (__msg.flags & ES58X_FLAG_FD_DATA)				\
 		__msg_len = canfd_sanitize_len(__msg.len);		\
 	else								\
 		__msg_len = can_cc_dlc2len(__msg.dlc);			\
 									\
 	offsetof(typeof(__msg), data[__msg_len]);			\
 })

 static enum es58x_fd_cmd_type es58x_fd_cmd_type(struct net_device *netdev)
 {
 	u32 ctrlmode = es58x_priv(netdev)->can.ctrlmode;

 	if (ctrlmode & (CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO))
 		return ES58X_FD_CMD_TYPE_CANFD;
 	else
 		return ES58X_FD_CMD_TYPE_CAN;
 }

 static u16 es58x_fd_get_msg_len(const union es58x_urb_cmd *urb_cmd)
 {
 	return get_unaligned_le16(&urb_cmd->es58x_fd_urb_cmd.msg_len);
 }

 static int es58x_fd_echo_msg(struct net_device *netdev,
 			     const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	struct es58x_priv *priv = es58x_priv(netdev);
 	const struct es58x_fd_echo_msg *echo_msg;
 	struct es58x_device *es58x_dev = priv->es58x_dev;
 	u64 *tstamps = es58x_dev->timestamps;
 	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	int i, num_element;
 	u32 rcv_packet_idx;

 	const u32 mask = GENMASK(31, sizeof(echo_msg->packet_idx) * 8);

 	num_element = es58x_msg_num_element(es58x_dev->dev,
 					    es58x_fd_urb_cmd->echo_msg,
 					    msg_len);
 	if (num_element < 0)
 		return num_element;
 	echo_msg = es58x_fd_urb_cmd->echo_msg;

 	rcv_packet_idx = (priv->tx_tail & mask) | echo_msg[0].packet_idx;
 	for (i = 0; i < num_element; i++) {
 		if ((u8)rcv_packet_idx != echo_msg[i].packet_idx) {
 			netdev_err(netdev, "Packet idx jumped from %u to %u\n",
 				   (u8)rcv_packet_idx - 1,
 				   echo_msg[i].packet_idx);
 			return -EBADMSG;
 		}

 		tstamps[i] = get_unaligned_le64(&echo_msg[i].timestamp);
 		rcv_packet_idx++;
 	}

 	return es58x_can_get_echo_skb(netdev, priv->tx_tail, tstamps, num_element);
 }

 static int es58x_fd_rx_can_msg(struct net_device *netdev,
 			       const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
 	const u8 *rx_can_msg_buf = es58x_fd_urb_cmd->rx_can_msg_buf;
 	u16 rx_can_msg_buf_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	int pkts, ret;

 	ret = es58x_check_msg_max_len(es58x_dev->dev,
 				      es58x_fd_urb_cmd->rx_can_msg_buf,
 				      rx_can_msg_buf_len);
 	if (ret)
 		return ret;

 	for (pkts = 0; rx_can_msg_buf_len > 0; pkts++) {
 		const struct es58x_fd_rx_can_msg *rx_can_msg =
 		    (const struct es58x_fd_rx_can_msg *)rx_can_msg_buf;
 		bool is_can_fd = !!(rx_can_msg->flags & ES58X_FLAG_FD_DATA);
 		/* rx_can_msg_len is the length of the rx_can_msg
 		 * buffer. Not to be confused with rx_can_msg->len
 		 * which is the length of the CAN payload
 		 * rx_can_msg->data.
 		 */
 		u16 rx_can_msg_len = es58x_fd_sizeof_rx_tx_msg(*rx_can_msg);

 		if (rx_can_msg_len > rx_can_msg_buf_len) {
 			netdev_err(netdev,
 				   "%s: Expected a rx_can_msg of size %d but only %d bytes are left in rx_can_msg_buf\n",
 				   __func__,
 				   rx_can_msg_len, rx_can_msg_buf_len);
 			return -EMSGSIZE;
 		}
 		if (rx_can_msg->len > CANFD_MAX_DLEN) {
 			netdev_err(netdev,
 				   "%s: Data length is %d but maximum should be %d\n",
 				   __func__, rx_can_msg->len, CANFD_MAX_DLEN);
 			return -EMSGSIZE;
 		}

 		if (netif_running(netdev)) {
 			u64 tstamp = get_unaligned_le64(&rx_can_msg->timestamp);
 			canid_t can_id = get_unaligned_le32(&rx_can_msg->can_id);
 			u8 dlc;

 			if (is_can_fd)
 				dlc = can_fd_len2dlc(rx_can_msg->len);
 			else
 				dlc = rx_can_msg->dlc;

 			ret = es58x_rx_can_msg(netdev, tstamp, rx_can_msg->data,
 					       can_id, rx_can_msg->flags, dlc);
 			if (ret)
 				break;
 		}

 		rx_can_msg_buf_len -= rx_can_msg_len;
 		rx_can_msg_buf += rx_can_msg_len;
 	}

 	if (!netif_running(netdev)) {
 		if (net_ratelimit())
 			netdev_info(netdev,
 				    "%s: %s is down, dropping %d rx packets\n",
 				    __func__, netdev->name, pkts);
 		netdev->stats.rx_dropped += pkts;
 	}

 	return ret;
 }

 static int es58x_fd_rx_event_msg(struct net_device *netdev,
 				 const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
 	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	const struct es58x_fd_rx_event_msg *rx_event_msg;
 	int ret;

 	ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len);
 	if (ret)
 		return ret;

 	rx_event_msg = &es58x_fd_urb_cmd->rx_event_msg;

 	return es58x_rx_err_msg(netdev, rx_event_msg->error_code,
 				rx_event_msg->event_code,
 				get_unaligned_le64(&rx_event_msg->timestamp));
 }

 static int es58x_fd_rx_cmd_ret_u32(struct net_device *netdev,
 				   const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd,
 				   enum es58x_ret_type cmd_ret_type)
 {
 	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
 	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	int ret;

 	ret = es58x_check_msg_len(es58x_dev->dev,
 				  es58x_fd_urb_cmd->rx_cmd_ret_le32, msg_len);
 	if (ret)
 		return ret;

 	return es58x_rx_cmd_ret_u32(netdev, cmd_ret_type,
 				    get_unaligned_le32(&es58x_fd_urb_cmd->rx_cmd_ret_le32));
 }

 static int es58x_fd_tx_ack_msg(struct net_device *netdev,
 			       const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
 	const struct es58x_fd_tx_ack_msg *tx_ack_msg;
 	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	int ret;

 	tx_ack_msg = &es58x_fd_urb_cmd->tx_ack_msg;
 	ret = es58x_check_msg_len(es58x_dev->dev, *tx_ack_msg, msg_len);
 	if (ret)
 		return ret;

 	return es58x_tx_ack_msg(netdev,
 				get_unaligned_le16(&tx_ack_msg->tx_free_entries),
 				get_unaligned_le32(&tx_ack_msg->rx_cmd_ret_le32));
 }

 static int es58x_fd_can_cmd_id(struct es58x_device *es58x_dev,
 			       const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	struct net_device *netdev;
 	int ret;

 	ret = es58x_get_netdev(es58x_dev, es58x_fd_urb_cmd->channel_idx,
 			       ES58X_FD_CHANNEL_IDX_OFFSET, &netdev);
 	if (ret)
 		return ret;

 	switch ((enum es58x_fd_can_cmd_id)es58x_fd_urb_cmd->cmd_id) {
 	case ES58X_FD_CAN_CMD_ID_ENABLE_CHANNEL:
 		return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
 					       ES58X_RET_TYPE_ENABLE_CHANNEL);

 	case ES58X_FD_CAN_CMD_ID_DISABLE_CHANNEL:
 		return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
 					       ES58X_RET_TYPE_DISABLE_CHANNEL);

 	case ES58X_FD_CAN_CMD_ID_TX_MSG:
 		return es58x_fd_tx_ack_msg(netdev, es58x_fd_urb_cmd);

 	case ES58X_FD_CAN_CMD_ID_ECHO_MSG:
 		return es58x_fd_echo_msg(netdev, es58x_fd_urb_cmd);

 	case ES58X_FD_CAN_CMD_ID_RX_MSG:
 		return es58x_fd_rx_can_msg(netdev, es58x_fd_urb_cmd);

 	case ES58X_FD_CAN_CMD_ID_RESET_RX:
 		return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
 					       ES58X_RET_TYPE_RESET_RX);

 	case ES58X_FD_CAN_CMD_ID_RESET_TX:
 		return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
 					       ES58X_RET_TYPE_RESET_TX);

 	case ES58X_FD_CAN_CMD_ID_ERROR_OR_EVENT_MSG:
 		return es58x_fd_rx_event_msg(netdev, es58x_fd_urb_cmd);

 	default:
 		return -EBADRQC;
 	}
 }

 static int es58x_fd_device_cmd_id(struct es58x_device *es58x_dev,
 				  const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
 {
 	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
 	int ret;

 	switch ((enum es58x_fd_dev_cmd_id)es58x_fd_urb_cmd->cmd_id) {
 	case ES58X_FD_DEV_CMD_ID_TIMESTAMP:
 		ret = es58x_check_msg_len(es58x_dev->dev,
 					  es58x_fd_urb_cmd->timestamp, msg_len);
 		if (ret)
 			return ret;
 		es58x_rx_timestamp(es58x_dev,
 				   get_unaligned_le64(&es58x_fd_urb_cmd->timestamp));
 		return 0;

 	default:
 		return -EBADRQC;
 	}
 }

 static int es58x_fd_handle_urb_cmd(struct es58x_device *es58x_dev,
 				   const union es58x_urb_cmd *urb_cmd)
 {
 	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd;
 	int ret;

 	es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;

 	switch ((enum es58x_fd_cmd_type)es58x_fd_urb_cmd->cmd_type) {
 	case ES58X_FD_CMD_TYPE_CAN:
 	case ES58X_FD_CMD_TYPE_CANFD:
 		ret = es58x_fd_can_cmd_id(es58x_dev, es58x_fd_urb_cmd);
 		break;

 	case ES58X_FD_CMD_TYPE_DEVICE:
 		ret = es58x_fd_device_cmd_id(es58x_dev, es58x_fd_urb_cmd);
 		break;

 	default:
 		ret = -EBADRQC;
 		break;
 	}

 	if (ret == -EBADRQC)
 		dev_err(es58x_dev->dev,
 			"%s: Unknown command type (0x%02X) and command ID (0x%02X) combination\n",
 			__func__, es58x_fd_urb_cmd->cmd_type,
 			es58x_fd_urb_cmd->cmd_id);

 	return ret;
 }

 static void es58x_fd_fill_urb_header(union es58x_urb_cmd *urb_cmd, u8 cmd_type,
 				     u8 cmd_id, u8 channel_idx, u16 msg_len)
 {
 	struct es58x_fd_urb_cmd *es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;

 	es58x_fd_urb_cmd->SOF = cpu_to_le16(es58x_fd_param.tx_start_of_frame);
 	es58x_fd_urb_cmd->cmd_type = cmd_type;
 	es58x_fd_urb_cmd->cmd_id = cmd_id;
 	es58x_fd_urb_cmd->channel_idx = channel_idx;
 	es58x_fd_urb_cmd->msg_len = cpu_to_le16(msg_len);
 }

 static int es58x_fd_tx_can_msg(struct es58x_priv *priv,
 			       const struct sk_buff *skb)
 {
 	struct es58x_device *es58x_dev = priv->es58x_dev;
 	union es58x_urb_cmd *urb_cmd = priv->tx_urb->transfer_buffer;
 	struct es58x_fd_urb_cmd *es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;
 	struct can_frame *cf = (struct can_frame *)skb->data;
 	struct es58x_fd_tx_can_msg *tx_can_msg;
 	bool is_fd = can_is_canfd_skb(skb);
 	u16 msg_len;
 	int ret;

 	if (priv->tx_can_msg_cnt == 0) {
 		msg_len = 0;
 		es58x_fd_fill_urb_header(urb_cmd,
 					 is_fd ? ES58X_FD_CMD_TYPE_CANFD
 					       : ES58X_FD_CMD_TYPE_CAN,
 					 ES58X_FD_CAN_CMD_ID_TX_MSG_NO_ACK,
 					 priv->channel_idx, msg_len);
 	} else {
 		msg_len = es58x_fd_get_msg_len(urb_cmd);
 	}

 	ret = es58x_check_msg_max_len(es58x_dev->dev,
 				      es58x_fd_urb_cmd->tx_can_msg_buf,
 				      msg_len + sizeof(*tx_can_msg));
 	if (ret)
 		return ret;

 	/* Fill message contents. */
 	tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
 	tx_can_msg->packet_idx = (u8)priv->tx_head;
 	put_unaligned_le32(es58x_get_raw_can_id(cf), &tx_can_msg->can_id);
 	tx_can_msg->flags = (u8)es58x_get_flags(skb);
 	if (is_fd)
 		tx_can_msg->len = cf->len;
 	else
 		tx_can_msg->dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
 	memcpy(tx_can_msg->data, cf->data, cf->len);

 	/* Calculate new sizes */
 	msg_len += es58x_fd_sizeof_rx_tx_msg(*tx_can_msg);
 	priv->tx_urb->transfer_buffer_length = es58x_get_urb_cmd_len(es58x_dev,
 								     msg_len);
 	put_unaligned_le16(msg_len, &es58x_fd_urb_cmd->msg_len);

 	return 0;
 }

 static void es58x_fd_convert_bittiming(struct es58x_fd_bittiming *es58x_fd_bt,
 				       struct can_bittiming *bt)
 {
 	/* The actual value set in the hardware registers is one less
 	 * than the functional value.
 	 */
 	const int offset = 1;

 	es58x_fd_bt->bitrate = cpu_to_le32(bt->bitrate);
 	es58x_fd_bt->tseg1 =
 	    cpu_to_le16(bt->prop_seg + bt->phase_seg1 - offset);
 	es58x_fd_bt->tseg2 = cpu_to_le16(bt->phase_seg2 - offset);
 	es58x_fd_bt->brp = cpu_to_le16(bt->brp - offset);
 	es58x_fd_bt->sjw = cpu_to_le16(bt->sjw - offset);
 }

 static int es58x_fd_enable_channel(struct es58x_priv *priv)
 {
 	struct es58x_device *es58x_dev = priv->es58x_dev;
 	struct net_device *netdev = es58x_dev->netdev[priv->channel_idx];
 	struct es58x_fd_tx_conf_msg tx_conf_msg = { 0 };
 	u32 ctrlmode;
 	size_t conf_len = 0;

 	es58x_fd_convert_bittiming(&tx_conf_msg.nominal_bittiming,
 				   &priv->can.bittiming);
 	ctrlmode = priv->can.ctrlmode;

 	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 		tx_conf_msg.samples_per_bit = ES58X_SAMPLES_PER_BIT_THREE;
 	else
 		tx_conf_msg.samples_per_bit = ES58X_SAMPLES_PER_BIT_ONE;
 	tx_conf_msg.sync_edge = ES58X_SYNC_EDGE_SINGLE;
 	tx_conf_msg.physical_layer = ES58X_PHYSICAL_LAYER_HIGH_SPEED;
 	tx_conf_msg.echo_mode = ES58X_ECHO_ON;
 	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 		tx_conf_msg.ctrlmode |= ES58X_FD_CTRLMODE_PASSIVE;
 	else
 		tx_conf_msg.ctrlmode |=  ES58X_FD_CTRLMODE_ACTIVE;

 	if (ctrlmode & CAN_CTRLMODE_FD_NON_ISO) {
 		tx_conf_msg.ctrlmode |= ES58X_FD_CTRLMODE_FD_NON_ISO;
 		tx_conf_msg.canfd_enabled = 1;
 	} else if (ctrlmode & CAN_CTRLMODE_FD) {
 		tx_conf_msg.ctrlmode |= ES58X_FD_CTRLMODE_FD;
 		tx_conf_msg.canfd_enabled = 1;
 	}

 	if (tx_conf_msg.canfd_enabled) {
 		es58x_fd_convert_bittiming(&tx_conf_msg.data_bittiming,
 					   &priv->can.data_bittiming);

 		if (can_tdc_is_enabled(&priv->can)) {
 			tx_conf_msg.tdc_enabled = 1;
 			tx_conf_msg.tdco = cpu_to_le16(priv->can.tdc.tdco);
 			tx_conf_msg.tdcf = cpu_to_le16(priv->can.tdc.tdcf);
 		}

 		conf_len = ES58X_FD_CANFD_CONF_LEN;
 	} else {
 		conf_len = ES58X_FD_CAN_CONF_LEN;
 	}

 	return es58x_send_msg(es58x_dev, es58x_fd_cmd_type(netdev),
 			      ES58X_FD_CAN_CMD_ID_ENABLE_CHANNEL,
 			      &tx_conf_msg, conf_len, priv->channel_idx);
 }

 static int es58x_fd_disable_channel(struct es58x_priv *priv)
 {
 	/* The type (ES58X_FD_CMD_TYPE_CAN or ES58X_FD_CMD_TYPE_CANFD) does
 	 * not matter here.
 	 */
 	return es58x_send_msg(priv->es58x_dev, ES58X_FD_CMD_TYPE_CAN,
 			      ES58X_FD_CAN_CMD_ID_DISABLE_CHANNEL,
 			      ES58X_EMPTY_MSG, 0, priv->channel_idx);
 }

 static int es58x_fd_get_timestamp(struct es58x_device *es58x_dev)
 {
 	return es58x_send_msg(es58x_dev, ES58X_FD_CMD_TYPE_DEVICE,
 			      ES58X_FD_DEV_CMD_ID_TIMESTAMP, ES58X_EMPTY_MSG,
 			      0, ES58X_CHANNEL_IDX_NA);
 }

 /* Nominal bittiming constants for ES582.1 and ES584.1 as specified in
  * the microcontroller datasheet: "SAM E70/S70/V70/V71 Family" section
  * 49.6.8 "MCAN Nominal Bit Timing and Prescaler Register" from
  * Microchip.
  *
  * The values from the specification are the hardware register
  * values. To convert them to the functional values, all ranges were
  * incremented by 1 (e.g. range [0..n-1] changed to [1..n]).
  */
 static const struct can_bittiming_const es58x_fd_nom_bittiming_const = {
 	.name = "ES582.1/ES584.1",
 	.tseg1_min = 2,
 	.tseg1_max = 256,
 	.tseg2_min = 2,
 	.tseg2_max = 128,
 	.sjw_max = 128,
 	.brp_min = 1,
 	.brp_max = 512,
 	.brp_inc = 1
 };

 /* Data bittiming constants for ES582.1 and ES584.1 as specified in
  * the microcontroller datasheet: "SAM E70/S70/V70/V71 Family" section
  * 49.6.4 "MCAN Data Bit Timing and Prescaler Register" from
  * Microchip.
  */
 static const struct can_bittiming_const es58x_fd_data_bittiming_const = {
 	.name = "ES582.1/ES584.1",
 	.tseg1_min = 2,
 	.tseg1_max = 32,
 	.tseg2_min = 1,
 	.tseg2_max = 16,
 	.sjw_max = 8,
 	.brp_min = 1,
 	.brp_max = 32,
 	.brp_inc = 1
 };

 /* Transmission Delay Compensation constants for ES582.1 and ES584.1
  * as specified in the microcontroller datasheet: "SAM E70/S70/V70/V71
  * Family" section 49.6.15 "MCAN Transmitter Delay Compensation
  * Register" from Microchip.
  */
 static const struct can_tdc_const es58x_tdc_const = {
 	.tdcv_min = 0,
 	.tdcv_max = 0, /* Manual mode not supported. */
 	.tdco_min = 0,
 	.tdco_max = 127,
 	.tdcf_min = 0,
 	.tdcf_max = 127
 };

 const struct es58x_parameters es58x_fd_param = {
 	.bittiming_const = &es58x_fd_nom_bittiming_const,
 	.data_bittiming_const = &es58x_fd_data_bittiming_const,
 	.tdc_const = &es58x_tdc_const,
 	/* The devices use NXP TJA1044G transievers which guarantee
 	 * the timing for data rates up to 5 Mbps. Bitrates up to 8
 	 * Mbps work in an optimal environment but are not recommended
 	 * for production environment.
 	 */
 	.bitrate_max = 8 * CAN_MBPS,
 	.clock = {.freq = 80 * CAN_MHZ},
 	.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY |
 	    CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO |
 	    CAN_CTRLMODE_CC_LEN8_DLC | CAN_CTRLMODE_TDC_AUTO,
 	.tx_start_of_frame = 0xCEFA,	/* FACE in little endian */
 	.rx_start_of_frame = 0xFECA,	/* CAFE in little endian */
 	.tx_urb_cmd_max_len = ES58X_FD_TX_URB_CMD_MAX_LEN,
 	.rx_urb_cmd_max_len = ES58X_FD_RX_URB_CMD_MAX_LEN,
 	/* Size of internal device TX queue is 500.
 	 *
 	 * However, when reaching value around 278, the device's busy
 	 * LED turns on and thus maximum value of 500 is never reached
 	 * in practice. Also, when this value is too high, some error
 	 * on the echo_msg were witnessed when the device is
 	 * recovering from bus off.
 	 *
 	 * For above reasons, a value that would prevent the device
 	 * from becoming busy was chosen. In practice, BQL would
 	 * prevent the value from even getting closer to below
 	 * maximum, so no impact on performance was measured.
 	 */
 	.fifo_mask = 255, /* echo_skb_max = 256 */
 	.dql_min_limit = CAN_FRAME_LEN_MAX * 15, /* Empirical value. */
 	.tx_bulk_max = ES58X_FD_TX_BULK_MAX,
 	.urb_cmd_header_len = ES58X_FD_URB_CMD_HEADER_LEN,
 	.rx_urb_max = ES58X_RX_URBS_MAX,
 	.tx_urb_max = ES58X_TX_URBS_MAX
 };

 const struct es58x_operators es58x_fd_ops = {
 	.get_msg_len = es58x_fd_get_msg_len,
 	.handle_urb_cmd = es58x_fd_handle_urb_cmd,
 	.fill_urb_header = es58x_fd_fill_urb_header,
 	.tx_can_msg = es58x_fd_tx_can_msg,
 	.enable_channel = es58x_fd_enable_channel,
 	.disable_channel = es58x_fd_disable_channel,
 	.reset_device = NULL, /* Not implemented in the device firmware. */
 	.get_timestamp = es58x_fd_get_timestamp
 };
	// SPDX-License-Identifier: GPL-2.0

	/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
	*
	* File es58x_fd.c: Adds support to ETAS ES582.1 and ES584.1 (naming
	* convention: we use the term "ES58X FD" when referring to those two
	* variants together).
	*
	* Copyright (c) 2019 Robert Bosch Engineering and Business Solutions. All rights reserved.
	* Copyright (c) 2020 ETAS K.K.. All rights reserved.
	* Copyright (c) 2020, 2021 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
	*/

	#include <linux/kernel.h>
	#include <asm/unaligned.h>

	#include "es58x_core.h"
	#include "es58x_fd.h"

	/**
	* es58x_fd_sizeof_rx_tx_msg() - Calculate the actual length of the
	* structure of a rx or tx message.
	* @msg: message of variable length, must have a dlc and a len fields.
	*
	* Even if RTR frames have actually no payload, the ES58X devices
	* still expect it. Must be a macro in order to accept several types
	* (struct es58x_fd_tx_can_msg and struct es58x_fd_rx_can_msg) as an
	* input.
	*
	* Return: length of the message.
	*/
	#define es58x_fd_sizeof_rx_tx_msg(msg) \
	({ \
	typeof(msg) __msg = (msg); \
	size_t __msg_len; \
	\
	if (__msg.flags & ES58X_FLAG_FD_DATA) \
	__msg_len = canfd_sanitize_len(__msg.len); \
	else \
	__msg_len = can_cc_dlc2len(__msg.dlc); \
	\
	offsetof(typeof(__msg), data[__msg_len]); \
	})

	static enum es58x_fd_cmd_type es58x_fd_cmd_type(struct net_device *netdev)
	{
	u32 ctrlmode = es58x_priv(netdev)->can.ctrlmode;

	if (ctrlmode & (CAN_CTRLMODE_FD \| CAN_CTRLMODE_FD_NON_ISO))
	return ES58X_FD_CMD_TYPE_CANFD;
	else
	return ES58X_FD_CMD_TYPE_CAN;
	}

	static u16 es58x_fd_get_msg_len(const union es58x_urb_cmd *urb_cmd)
	{
	return get_unaligned_le16(&urb_cmd->es58x_fd_urb_cmd.msg_len);
	}

	static int es58x_fd_echo_msg(struct net_device *netdev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	struct es58x_priv *priv = es58x_priv(netdev);
	const struct es58x_fd_echo_msg *echo_msg;
	struct es58x_device *es58x_dev = priv->es58x_dev;
	u64 *tstamps = es58x_dev->timestamps;
	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	int i, num_element;
	u32 rcv_packet_idx;

	const u32 mask = GENMASK(31, sizeof(echo_msg->packet_idx) * 8);

	num_element = es58x_msg_num_element(es58x_dev->dev,
	es58x_fd_urb_cmd->echo_msg,
	msg_len);
	if (num_element < 0)
	return num_element;
	echo_msg = es58x_fd_urb_cmd->echo_msg;

	rcv_packet_idx = (priv->tx_tail & mask) \| echo_msg[0].packet_idx;
	for (i = 0; i < num_element; i++) {
	if ((u8)rcv_packet_idx != echo_msg[i].packet_idx) {
	netdev_err(netdev, "Packet idx jumped from %u to %u\n",
	(u8)rcv_packet_idx - 1,
	echo_msg[i].packet_idx);
	return -EBADMSG;
	}

	tstamps[i] = get_unaligned_le64(&echo_msg[i].timestamp);
	rcv_packet_idx++;
	}

	return es58x_can_get_echo_skb(netdev, priv->tx_tail, tstamps, num_element);
	}

	static int es58x_fd_rx_can_msg(struct net_device *netdev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
	const u8 *rx_can_msg_buf = es58x_fd_urb_cmd->rx_can_msg_buf;
	u16 rx_can_msg_buf_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	int pkts, ret;

	ret = es58x_check_msg_max_len(es58x_dev->dev,
	es58x_fd_urb_cmd->rx_can_msg_buf,
	rx_can_msg_buf_len);
	if (ret)
	return ret;

	for (pkts = 0; rx_can_msg_buf_len > 0; pkts++) {
	const struct es58x_fd_rx_can_msg *rx_can_msg =
	(const struct es58x_fd_rx_can_msg *)rx_can_msg_buf;
	bool is_can_fd = !!(rx_can_msg->flags & ES58X_FLAG_FD_DATA);
	/* rx_can_msg_len is the length of the rx_can_msg
	* buffer. Not to be confused with rx_can_msg->len
	* which is the length of the CAN payload
	* rx_can_msg->data.
	*/
	u16 rx_can_msg_len = es58x_fd_sizeof_rx_tx_msg(*rx_can_msg);

	if (rx_can_msg_len > rx_can_msg_buf_len) {
	netdev_err(netdev,
	"%s: Expected a rx_can_msg of size %d but only %d bytes are left in rx_can_msg_buf\n",
	__func__,
	rx_can_msg_len, rx_can_msg_buf_len);
	return -EMSGSIZE;
	}
	if (rx_can_msg->len > CANFD_MAX_DLEN) {
	netdev_err(netdev,
	"%s: Data length is %d but maximum should be %d\n",
	__func__, rx_can_msg->len, CANFD_MAX_DLEN);
	return -EMSGSIZE;
	}

	if (netif_running(netdev)) {
	u64 tstamp = get_unaligned_le64(&rx_can_msg->timestamp);
	canid_t can_id = get_unaligned_le32(&rx_can_msg->can_id);
	u8 dlc;

	if (is_can_fd)
	dlc = can_fd_len2dlc(rx_can_msg->len);
	else
	dlc = rx_can_msg->dlc;

	ret = es58x_rx_can_msg(netdev, tstamp, rx_can_msg->data,
	can_id, rx_can_msg->flags, dlc);
	if (ret)
	break;
	}

	rx_can_msg_buf_len -= rx_can_msg_len;
	rx_can_msg_buf += rx_can_msg_len;
	}

	if (!netif_running(netdev)) {
	if (net_ratelimit())
	netdev_info(netdev,
	"%s: %s is down, dropping %d rx packets\n",
	__func__, netdev->name, pkts);
	netdev->stats.rx_dropped += pkts;
	}

	return ret;
	}

	static int es58x_fd_rx_event_msg(struct net_device *netdev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	const struct es58x_fd_rx_event_msg *rx_event_msg;
	int ret;

	ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len);
	if (ret)
	return ret;

	rx_event_msg = &es58x_fd_urb_cmd->rx_event_msg;

	return es58x_rx_err_msg(netdev, rx_event_msg->error_code,
	rx_event_msg->event_code,
	get_unaligned_le64(&rx_event_msg->timestamp));
	}

	static int es58x_fd_rx_cmd_ret_u32(struct net_device *netdev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd,
	enum es58x_ret_type cmd_ret_type)
	{
	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	int ret;

	ret = es58x_check_msg_len(es58x_dev->dev,
	es58x_fd_urb_cmd->rx_cmd_ret_le32, msg_len);
	if (ret)
	return ret;

	return es58x_rx_cmd_ret_u32(netdev, cmd_ret_type,
	get_unaligned_le32(&es58x_fd_urb_cmd->rx_cmd_ret_le32));
	}

	static int es58x_fd_tx_ack_msg(struct net_device *netdev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
	const struct es58x_fd_tx_ack_msg *tx_ack_msg;
	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	int ret;

	tx_ack_msg = &es58x_fd_urb_cmd->tx_ack_msg;
	ret = es58x_check_msg_len(es58x_dev->dev, *tx_ack_msg, msg_len);
	if (ret)
	return ret;

	return es58x_tx_ack_msg(netdev,
	get_unaligned_le16(&tx_ack_msg->tx_free_entries),
	get_unaligned_le32(&tx_ack_msg->rx_cmd_ret_le32));
	}

	static int es58x_fd_can_cmd_id(struct es58x_device *es58x_dev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	struct net_device *netdev;
	int ret;

	ret = es58x_get_netdev(es58x_dev, es58x_fd_urb_cmd->channel_idx,
	ES58X_FD_CHANNEL_IDX_OFFSET, &netdev);
	if (ret)
	return ret;

	switch ((enum es58x_fd_can_cmd_id)es58x_fd_urb_cmd->cmd_id) {
	case ES58X_FD_CAN_CMD_ID_ENABLE_CHANNEL:
	return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
	ES58X_RET_TYPE_ENABLE_CHANNEL);

	case ES58X_FD_CAN_CMD_ID_DISABLE_CHANNEL:
	return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
	ES58X_RET_TYPE_DISABLE_CHANNEL);

	case ES58X_FD_CAN_CMD_ID_TX_MSG:
	return es58x_fd_tx_ack_msg(netdev, es58x_fd_urb_cmd);

	case ES58X_FD_CAN_CMD_ID_ECHO_MSG:
	return es58x_fd_echo_msg(netdev, es58x_fd_urb_cmd);

	case ES58X_FD_CAN_CMD_ID_RX_MSG:
	return es58x_fd_rx_can_msg(netdev, es58x_fd_urb_cmd);

	case ES58X_FD_CAN_CMD_ID_RESET_RX:
	return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
	ES58X_RET_TYPE_RESET_RX);

	case ES58X_FD_CAN_CMD_ID_RESET_TX:
	return es58x_fd_rx_cmd_ret_u32(netdev, es58x_fd_urb_cmd,
	ES58X_RET_TYPE_RESET_TX);

	case ES58X_FD_CAN_CMD_ID_ERROR_OR_EVENT_MSG:
	return es58x_fd_rx_event_msg(netdev, es58x_fd_urb_cmd);

	default:
	return -EBADRQC;
	}
	}

	static int es58x_fd_device_cmd_id(struct es58x_device *es58x_dev,
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd)
	{
	u16 msg_len = get_unaligned_le16(&es58x_fd_urb_cmd->msg_len);
	int ret;

	switch ((enum es58x_fd_dev_cmd_id)es58x_fd_urb_cmd->cmd_id) {
	case ES58X_FD_DEV_CMD_ID_TIMESTAMP:
	ret = es58x_check_msg_len(es58x_dev->dev,
	es58x_fd_urb_cmd->timestamp, msg_len);
	if (ret)
	return ret;
	es58x_rx_timestamp(es58x_dev,
	get_unaligned_le64(&es58x_fd_urb_cmd->timestamp));
	return 0;

	default:
	return -EBADRQC;
	}
	}

	static int es58x_fd_handle_urb_cmd(struct es58x_device *es58x_dev,
	const union es58x_urb_cmd *urb_cmd)
	{
	const struct es58x_fd_urb_cmd *es58x_fd_urb_cmd;
	int ret;

	es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;

	switch ((enum es58x_fd_cmd_type)es58x_fd_urb_cmd->cmd_type) {
	case ES58X_FD_CMD_TYPE_CAN:
	case ES58X_FD_CMD_TYPE_CANFD:
	ret = es58x_fd_can_cmd_id(es58x_dev, es58x_fd_urb_cmd);
	break;

	case ES58X_FD_CMD_TYPE_DEVICE:
	ret = es58x_fd_device_cmd_id(es58x_dev, es58x_fd_urb_cmd);
	break;

	default:
	ret = -EBADRQC;
	break;
	}

	if (ret == -EBADRQC)
	dev_err(es58x_dev->dev,
	"%s: Unknown command type (0x%02X) and command ID (0x%02X) combination\n",
	__func__, es58x_fd_urb_cmd->cmd_type,
	es58x_fd_urb_cmd->cmd_id);

	return ret;
	}

	static void es58x_fd_fill_urb_header(union es58x_urb_cmd *urb_cmd, u8 cmd_type,
	u8 cmd_id, u8 channel_idx, u16 msg_len)
	{
	struct es58x_fd_urb_cmd *es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;

	es58x_fd_urb_cmd->SOF = cpu_to_le16(es58x_fd_param.tx_start_of_frame);
	es58x_fd_urb_cmd->cmd_type = cmd_type;
	es58x_fd_urb_cmd->cmd_id = cmd_id;
	es58x_fd_urb_cmd->channel_idx = channel_idx;
	es58x_fd_urb_cmd->msg_len = cpu_to_le16(msg_len);
	}

	static int es58x_fd_tx_can_msg(struct es58x_priv *priv,
	const struct sk_buff *skb)
	{
	struct es58x_device *es58x_dev = priv->es58x_dev;
	union es58x_urb_cmd *urb_cmd = priv->tx_urb->transfer_buffer;
	struct es58x_fd_urb_cmd *es58x_fd_urb_cmd = &urb_cmd->es58x_fd_urb_cmd;
	struct can_frame cf = (struct can_frame )skb->data;
	struct es58x_fd_tx_can_msg *tx_can_msg;
	bool is_fd = can_is_canfd_skb(skb);
	u16 msg_len;
	int ret;

	if (priv->tx_can_msg_cnt == 0) {
	msg_len = 0;
	es58x_fd_fill_urb_header(urb_cmd,
	is_fd ? ES58X_FD_CMD_TYPE_CANFD
	: ES58X_FD_CMD_TYPE_CAN,
	ES58X_FD_CAN_CMD_ID_TX_MSG_NO_ACK,
	priv->channel_idx, msg_len);
	} else {
	msg_len = es58x_fd_get_msg_len(urb_cmd);
	}

	ret = es58x_check_msg_max_len(es58x_dev->dev,
	es58x_fd_urb_cmd->tx_can_msg_buf,
	msg_len + sizeof(*tx_can_msg));
	if (ret)
	return ret;

	/* Fill message contents. */
	tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
	tx_can_msg->packet_idx = (u8)priv->tx_head;
	put_unaligned_le32(es58x_get_raw_can_id(cf), &tx_can_msg->can_id);
	tx_can_msg->flags = (u8)es58x_get_flags(skb);
	if (is_fd)
	tx_can_msg->len = cf->len;
	else
	tx_can_msg->dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
	memcpy(tx_can_msg->data, cf->data, cf->len);

	/* Calculate new sizes */
	msg_len += es58x_fd_sizeof_rx_tx_msg(*tx_can_msg);
	priv->tx_urb->transfer_buffer_length = es58x_get_urb_cmd_len(es58x_dev,
	msg_len);
	put_unaligned_le16(msg_len, &es58x_fd_urb_cmd->msg_len);

	return 0;
	}

	static void es58x_fd_convert_bittiming(struct es58x_fd_bittiming *es58x_fd_bt,
	struct can_bittiming *bt)
	{
	/* The actual value set in the hardware registers is one less
	* than the functional value.
	*/
	const int offset = 1;

	es58x_fd_bt->bitrate = cpu_to_le32(bt->bitrate);
	es58x_fd_bt->tseg1 =
	cpu_to_le16(bt->prop_seg + bt->phase_seg1 - offset);
	es58x_fd_bt->tseg2 = cpu_to_le16(bt->phase_seg2 - offset);
	es58x_fd_bt->brp = cpu_to_le16(bt->brp - offset);
	es58x_fd_bt->sjw = cpu_to_le16(bt->sjw - offset);
	}

	static int es58x_fd_enable_channel(struct es58x_priv *priv)
	{
	struct es58x_device *es58x_dev = priv->es58x_dev;
	struct net_device *netdev = es58x_dev->netdev[priv->channel_idx];
	struct es58x_fd_tx_conf_msg tx_conf_msg = { 0 };
	u32 ctrlmode;
	size_t conf_len = 0;

	es58x_fd_convert_bittiming(&tx_conf_msg.nominal_bittiming,
	&priv->can.bittiming);
	ctrlmode = priv->can.ctrlmode;

	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
	tx_conf_msg.samples_per_bit = ES58X_SAMPLES_PER_BIT_THREE;
	else
	tx_conf_msg.samples_per_bit = ES58X_SAMPLES_PER_BIT_ONE;
	tx_conf_msg.sync_edge = ES58X_SYNC_EDGE_SINGLE;
	tx_conf_msg.physical_layer = ES58X_PHYSICAL_LAYER_HIGH_SPEED;
	tx_conf_msg.echo_mode = ES58X_ECHO_ON;
	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
	tx_conf_msg.ctrlmode \|= ES58X_FD_CTRLMODE_PASSIVE;
	else
	tx_conf_msg.ctrlmode \|= ES58X_FD_CTRLMODE_ACTIVE;

	if (ctrlmode & CAN_CTRLMODE_FD_NON_ISO) {
	tx_conf_msg.ctrlmode \|= ES58X_FD_CTRLMODE_FD_NON_ISO;
	tx_conf_msg.canfd_enabled = 1;
	} else if (ctrlmode & CAN_CTRLMODE_FD) {
	tx_conf_msg.ctrlmode \|= ES58X_FD_CTRLMODE_FD;
	tx_conf_msg.canfd_enabled = 1;
	}

	if (tx_conf_msg.canfd_enabled) {
	es58x_fd_convert_bittiming(&tx_conf_msg.data_bittiming,
	&priv->can.data_bittiming);

	if (can_tdc_is_enabled(&priv->can)) {
	tx_conf_msg.tdc_enabled = 1;
	tx_conf_msg.tdco = cpu_to_le16(priv->can.tdc.tdco);
	tx_conf_msg.tdcf = cpu_to_le16(priv->can.tdc.tdcf);
	}

	conf_len = ES58X_FD_CANFD_CONF_LEN;
	} else {
	conf_len = ES58X_FD_CAN_CONF_LEN;
	}

	return es58x_send_msg(es58x_dev, es58x_fd_cmd_type(netdev),
	ES58X_FD_CAN_CMD_ID_ENABLE_CHANNEL,
	&tx_conf_msg, conf_len, priv->channel_idx);
	}

	static int es58x_fd_disable_channel(struct es58x_priv *priv)
	{
	/* The type (ES58X_FD_CMD_TYPE_CAN or ES58X_FD_CMD_TYPE_CANFD) does
	* not matter here.
	*/
	return es58x_send_msg(priv->es58x_dev, ES58X_FD_CMD_TYPE_CAN,
	ES58X_FD_CAN_CMD_ID_DISABLE_CHANNEL,
	ES58X_EMPTY_MSG, 0, priv->channel_idx);
	}

	static int es58x_fd_get_timestamp(struct es58x_device *es58x_dev)
	{
	return es58x_send_msg(es58x_dev, ES58X_FD_CMD_TYPE_DEVICE,
	ES58X_FD_DEV_CMD_ID_TIMESTAMP, ES58X_EMPTY_MSG,
	0, ES58X_CHANNEL_IDX_NA);
	}

	/* Nominal bittiming constants for ES582.1 and ES584.1 as specified in
	* the microcontroller datasheet: "SAM E70/S70/V70/V71 Family" section
	* 49.6.8 "MCAN Nominal Bit Timing and Prescaler Register" from
	* Microchip.
	*
	* The values from the specification are the hardware register
	* values. To convert them to the functional values, all ranges were
	* incremented by 1 (e.g. range [0..n-1] changed to [1..n]).
	*/
	static const struct can_bittiming_const es58x_fd_nom_bittiming_const = {
	.name = "ES582.1/ES584.1",
	.tseg1_min = 2,
	.tseg1_max = 256,
	.tseg2_min = 2,
	.tseg2_max = 128,
	.sjw_max = 128,
	.brp_min = 1,
	.brp_max = 512,
	.brp_inc = 1
	};

	/* Data bittiming constants for ES582.1 and ES584.1 as specified in
	* the microcontroller datasheet: "SAM E70/S70/V70/V71 Family" section
	* 49.6.4 "MCAN Data Bit Timing and Prescaler Register" from
	* Microchip.
	*/
	static const struct can_bittiming_const es58x_fd_data_bittiming_const = {
	.name = "ES582.1/ES584.1",
	.tseg1_min = 2,
	.tseg1_max = 32,
	.tseg2_min = 1,
	.tseg2_max = 16,
	.sjw_max = 8,
	.brp_min = 1,
	.brp_max = 32,
	.brp_inc = 1
	};

	/* Transmission Delay Compensation constants for ES582.1 and ES584.1
	* as specified in the microcontroller datasheet: "SAM E70/S70/V70/V71
	* Family" section 49.6.15 "MCAN Transmitter Delay Compensation
	* Register" from Microchip.
	*/
	static const struct can_tdc_const es58x_tdc_const = {
	.tdcv_min = 0,
	.tdcv_max = 0, /* Manual mode not supported. */
	.tdco_min = 0,
	.tdco_max = 127,
	.tdcf_min = 0,
	.tdcf_max = 127
	};

	const struct es58x_parameters es58x_fd_param = {
	.bittiming_const = &es58x_fd_nom_bittiming_const,
	.data_bittiming_const = &es58x_fd_data_bittiming_const,
	.tdc_const = &es58x_tdc_const,
	/* The devices use NXP TJA1044G transievers which guarantee
	* the timing for data rates up to 5 Mbps. Bitrates up to 8
	* Mbps work in an optimal environment but are not recommended
	* for production environment.
	*/
	.bitrate_max = 8 * CAN_MBPS,
	.clock = {.freq = 80 * CAN_MHZ},
	.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK \| CAN_CTRLMODE_LISTENONLY \|
	CAN_CTRLMODE_3_SAMPLES \| CAN_CTRLMODE_FD \| CAN_CTRLMODE_FD_NON_ISO \|
	CAN_CTRLMODE_CC_LEN8_DLC \| CAN_CTRLMODE_TDC_AUTO,
	.tx_start_of_frame = 0xCEFA, /* FACE in little endian */
	.rx_start_of_frame = 0xFECA, /* CAFE in little endian */
	.tx_urb_cmd_max_len = ES58X_FD_TX_URB_CMD_MAX_LEN,
	.rx_urb_cmd_max_len = ES58X_FD_RX_URB_CMD_MAX_LEN,
	/* Size of internal device TX queue is 500.
	*
	* However, when reaching value around 278, the device's busy
	* LED turns on and thus maximum value of 500 is never reached
	* in practice. Also, when this value is too high, some error
	* on the echo_msg were witnessed when the device is
	* recovering from bus off.
	*
	* For above reasons, a value that would prevent the device
	* from becoming busy was chosen. In practice, BQL would
	* prevent the value from even getting closer to below
	* maximum, so no impact on performance was measured.
	*/
	.fifo_mask = 255, /* echo_skb_max = 256 */
	.dql_min_limit = CAN_FRAME_LEN_MAX * 15, /* Empirical value. */
	.tx_bulk_max = ES58X_FD_TX_BULK_MAX,
	.urb_cmd_header_len = ES58X_FD_URB_CMD_HEADER_LEN,
	.rx_urb_max = ES58X_RX_URBS_MAX,
	.tx_urb_max = ES58X_TX_URBS_MAX
	};

	const struct es58x_operators es58x_fd_ops = {
	.get_msg_len = es58x_fd_get_msg_len,
	.handle_urb_cmd = es58x_fd_handle_urb_cmd,
	.fill_urb_header = es58x_fd_fill_urb_header,
	.tx_can_msg = es58x_fd_tx_can_msg,
	.enable_channel = es58x_fd_enable_channel,
	.disable_channel = es58x_fd_disable_channel,
	.reset_device = NULL, /* Not implemented in the device firmware. */
	.get_timestamp = es58x_fd_get_timestamp
	};