can: peak: add support for PEAK PCAN-PCIe FD CAN-FD boards (8ac8321e) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/net/can/Kconfig

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Original line number	Diff line number	Diff line
		@@ -142,6 +142,7 @@ source "drivers/net/can/cc770/Kconfig"
		source "drivers/net/can/ifi_canfd/Kconfig"
		source "drivers/net/can/m_can/Kconfig"
		source "drivers/net/can/mscan/Kconfig"
		source "drivers/net/can/peak_canfd/Kconfig"
		source "drivers/net/can/rcar/Kconfig"
		source "drivers/net/can/sja1000/Kconfig"
		source "drivers/net/can/softing/Kconfig"

drivers/net/can/Makefile

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Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@ obj-$(CONFIG_CAN_IFI_CANFD) += ifi_canfd/
		obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o
		obj-$(CONFIG_CAN_MSCAN) += mscan/
		obj-$(CONFIG_CAN_M_CAN) += m_can/
		obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_canfd/
		obj-$(CONFIG_CAN_SJA1000) += sja1000/
		obj-$(CONFIG_CAN_SUN4I) += sun4i_can.o
		obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o

drivers/net/can/peak_canfd/Kconfig

0 → 100644

+13 −0

Original line number	Diff line number	Diff line
		config CAN_PEAK_PCIEFD
		depends on PCI
		tristate "PEAK-System PCAN-PCIe FD cards"
		---help---
		This driver adds support for the PEAK-System PCI Express FD
		CAN-FD cards family.
		These 1x or 2x CAN-FD channels cards offer CAN 2.0 a/b as well as
		CAN-FD access to the CAN bus. Besides the nominal bitrate of up to
		1 Mbit/s, the data bytes of CAN-FD frames can be transmitted with
		up to 12 Mbit/s. A galvanic isolation of the CAN ports protects the
		electronics of the card and the respective computer against
		disturbances of up to 500 Volts. The PCAN-PCI Express FD can be
		operated with ambient temperatures in a range of -40 to +85 °C.

drivers/net/can/peak_canfd/Makefile

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Original line number	Diff line number	Diff line
		#
		# Makefile for the PEAK-System CAN-FD IP module drivers
		#
		obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_pciefd.o
		peak_pciefd-y := peak_pciefd_main.o peak_canfd.o

drivers/net/can/peak_canfd/peak_canfd.c

0 → 100644

+801 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
		* Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
		*
		* Copyright (C) 2016 PEAK System-Technik GmbH
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the version 2 of the GNU General Public License
		* as published by the Free Software Foundation
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*/

		#include <linux/can.h>
		#include <linux/can/dev.h>

		#include "peak_canfd_user.h"

		/* internal IP core cache size (used as default echo skbs max number) */
		#define PCANFD_ECHO_SKB_MAX 24

		/* bittiming ranges of the PEAK-System PC CAN-FD interfaces */
		static const struct can_bittiming_const peak_canfd_nominal_const = {
		.name = "peak_canfd",
		.tseg1_min = 1,
		.tseg1_max = (1 << PUCAN_TSLOW_TSGEG1_BITS),
		.tseg2_min = 1,
		.tseg2_max = (1 << PUCAN_TSLOW_TSGEG2_BITS),
		.sjw_max = (1 << PUCAN_TSLOW_SJW_BITS),
		.brp_min = 1,
		.brp_max = (1 << PUCAN_TSLOW_BRP_BITS),
		.brp_inc = 1,
		};

		static const struct can_bittiming_const peak_canfd_data_const = {
		.name = "peak_canfd",
		.tseg1_min = 1,
		.tseg1_max = (1 << PUCAN_TFAST_TSGEG1_BITS),
		.tseg2_min = 1,
		.tseg2_max = (1 << PUCAN_TFAST_TSGEG2_BITS),
		.sjw_max = (1 << PUCAN_TFAST_SJW_BITS),
		.brp_min = 1,
		.brp_max = (1 << PUCAN_TFAST_BRP_BITS),
		.brp_inc = 1,
		};

		static struct peak_canfd_priv pucan_init_cmd(struct peak_canfd_priv priv)
		{
		priv->cmd_len = 0;
		return priv;
		}

		static void pucan_add_cmd(struct peak_canfd_priv priv, int cmd_op)
		{
		struct pucan_command *cmd;

		if (priv->cmd_len + sizeof(*cmd) > priv->cmd_maxlen)
		return NULL;

		cmd = priv->cmd_buffer + priv->cmd_len;

		/* reset all unused bit to default */
		memset(cmd, 0, sizeof(*cmd));

		cmd->opcode_channel = pucan_cmd_opcode_channel(priv->index, cmd_op);
		priv->cmd_len += sizeof(*cmd);

		return cmd;
		}

		static int pucan_write_cmd(struct peak_canfd_priv *priv)
		{
		int err;

		if (priv->pre_cmd) {
		err = priv->pre_cmd(priv);
		if (err)
		return err;
		}

		err = priv->write_cmd(priv);
		if (err)
		return err;

		if (priv->post_cmd)
		err = priv->post_cmd(priv);

		return err;
		}

		/* uCAN commands interface functions */
		static int pucan_set_reset_mode(struct peak_canfd_priv *priv)
		{
		pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_RESET_MODE);
		return pucan_write_cmd(priv);
		}

		static int pucan_set_normal_mode(struct peak_canfd_priv *priv)
		{
		int err;

		pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_NORMAL_MODE);
		err = pucan_write_cmd(priv);
		if (!err)
		priv->can.state = CAN_STATE_ERROR_ACTIVE;

		return err;
		}

		static int pucan_set_listen_only_mode(struct peak_canfd_priv *priv)
		{
		int err;

		pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_LISTEN_ONLY_MODE);
		err = pucan_write_cmd(priv);
		if (!err)
		priv->can.state = CAN_STATE_ERROR_ACTIVE;

		return err;
		}

		static int pucan_set_timing_slow(struct peak_canfd_priv *priv,
		const struct can_bittiming *pbt)
		{
		struct pucan_timing_slow *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TIMING_SLOW);

		cmd->sjw_t = PUCAN_TSLOW_SJW_T(pbt->sjw - 1,
		priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES);
		cmd->tseg1 = PUCAN_TSLOW_TSEG1(pbt->prop_seg + pbt->phase_seg1 - 1);
		cmd->tseg2 = PUCAN_TSLOW_TSEG2(pbt->phase_seg2 - 1);
		cmd->brp = cpu_to_le16(PUCAN_TSLOW_BRP(pbt->brp - 1));

		cmd->ewl = 96; /* default */

		netdev_dbg(priv->ndev,
		"nominal: brp=%u tseg1=%u tseg2=%u sjw=%u\n",
		le16_to_cpu(cmd->brp), cmd->tseg1, cmd->tseg2, cmd->sjw_t);

		return pucan_write_cmd(priv);
		}

		static int pucan_set_timing_fast(struct peak_canfd_priv *priv,
		const struct can_bittiming *pbt)
		{
		struct pucan_timing_fast *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TIMING_FAST);

		cmd->sjw = PUCAN_TFAST_SJW(pbt->sjw - 1);
		cmd->tseg1 = PUCAN_TFAST_TSEG1(pbt->prop_seg + pbt->phase_seg1 - 1);
		cmd->tseg2 = PUCAN_TFAST_TSEG2(pbt->phase_seg2 - 1);
		cmd->brp = cpu_to_le16(PUCAN_TFAST_BRP(pbt->brp - 1));

		netdev_dbg(priv->ndev,
		"data: brp=%u tseg1=%u tseg2=%u sjw=%u\n",
		le16_to_cpu(cmd->brp), cmd->tseg1, cmd->tseg2, cmd->sjw);

		return pucan_write_cmd(priv);
		}

		static int pucan_set_std_filter(struct peak_canfd_priv *priv, u8 row, u32 mask)
		{
		struct pucan_std_filter *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_SET_STD_FILTER);

		/* all the 11-bits CAN ID values are represented by one bit in a
		* 64 rows array of 32 bits: the upper 6 bits of the CAN ID select the
		* row while the lowest 5 bits select the bit in that row.
		*
		* bit filter
		* 1 passed
		* 0 discarded
		*/

		/* select the row */
		cmd->idx = row;

		/* set/unset bits in the row */
		cmd->mask = cpu_to_le32(mask);

		return pucan_write_cmd(priv);
		}

		static int pucan_tx_abort(struct peak_canfd_priv *priv, u16 flags)
		{
		struct pucan_tx_abort *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TX_ABORT);

		cmd->flags = cpu_to_le16(flags);

		return pucan_write_cmd(priv);
		}

		static int pucan_clr_err_counters(struct peak_canfd_priv *priv)
		{
		struct pucan_wr_err_cnt *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_WR_ERR_CNT);

		cmd->sel_mask = cpu_to_le16(PUCAN_WRERRCNT_TE \| PUCAN_WRERRCNT_RE);
		cmd->tx_counter = 0;
		cmd->rx_counter = 0;

		return pucan_write_cmd(priv);
		}

		static int pucan_set_options(struct peak_canfd_priv *priv, u16 opt_mask)
		{
		struct pucan_options *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_SET_EN_OPTION);

		cmd->options = cpu_to_le16(opt_mask);

		return pucan_write_cmd(priv);
		}

		static int pucan_clr_options(struct peak_canfd_priv *priv, u16 opt_mask)
		{
		struct pucan_options *cmd;

		cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_CLR_DIS_OPTION);

		cmd->options = cpu_to_le16(opt_mask);

		return pucan_write_cmd(priv);
		}

		static int pucan_setup_rx_barrier(struct peak_canfd_priv *priv)
		{
		pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_RX_BARRIER);

		return pucan_write_cmd(priv);
		}

		/* handle the reception of one CAN frame */
		static int pucan_handle_can_rx(struct peak_canfd_priv *priv,
		struct pucan_rx_msg *msg)
		{
		struct net_device_stats *stats = &priv->ndev->stats;
		struct canfd_frame *cf;
		struct sk_buff *skb;
		const u16 rx_msg_flags = le16_to_cpu(msg->flags);
		u8 cf_len;

		if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN)
		cf_len = can_dlc2len(get_canfd_dlc(pucan_msg_get_dlc(msg)));
		else
		cf_len = get_can_dlc(pucan_msg_get_dlc(msg));

		/* if this frame is an echo, */
		if ((rx_msg_flags & PUCAN_MSG_LOOPED_BACK) &&
		!(rx_msg_flags & PUCAN_MSG_SELF_RECEIVE)) {
		int n;
		unsigned long flags;

		spin_lock_irqsave(&priv->echo_lock, flags);
		n = can_get_echo_skb(priv->ndev, msg->client);
		spin_unlock_irqrestore(&priv->echo_lock, flags);

		/* count bytes of the echo instead of skb */
		stats->tx_bytes += cf_len;
		stats->tx_packets++;

		if (n) {
		/* restart tx queue only if a slot is free */
		netif_wake_queue(priv->ndev);
		}

		return 0;
		}

		/* otherwise, it should be pushed into rx fifo */
		if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN) {
		/* CANFD frame case */
		skb = alloc_canfd_skb(priv->ndev, &cf);
		if (!skb)
		return -ENOMEM;

		if (rx_msg_flags & PUCAN_MSG_BITRATE_SWITCH)
		cf->flags \|= CANFD_BRS;

		if (rx_msg_flags & PUCAN_MSG_ERROR_STATE_IND)
		cf->flags \|= CANFD_ESI;
		} else {
		/* CAN 2.0 frame case */
		skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cf);
		if (!skb)
		return -ENOMEM;
		}

		cf->can_id = le32_to_cpu(msg->can_id);
		cf->len = cf_len;

		if (rx_msg_flags & PUCAN_MSG_EXT_ID)
		cf->can_id \|= CAN_EFF_FLAG;

		if (rx_msg_flags & PUCAN_MSG_RTR)
		cf->can_id \|= CAN_RTR_FLAG;
		else
		memcpy(cf->data, msg->d, cf->len);

		stats->rx_bytes += cf->len;
		stats->rx_packets++;

		netif_rx(skb);

		return 0;
		}

		/* handle rx/tx error counters notification */
		static int pucan_handle_error(struct peak_canfd_priv *priv,
		struct pucan_error_msg *msg)
		{
		priv->bec.txerr = msg->tx_err_cnt;
		priv->bec.rxerr = msg->rx_err_cnt;

		return 0;
		}

		/* handle status notification */
		static int pucan_handle_status(struct peak_canfd_priv *priv,
		struct pucan_status_msg *msg)
		{
		struct net_device *ndev = priv->ndev;
		struct net_device_stats *stats = &ndev->stats;
		struct can_frame *cf;
		struct sk_buff *skb;

		/* this STATUS is the CNF of the RX_BARRIER: Tx path can be setup */
		if (pucan_status_is_rx_barrier(msg)) {
		unsigned long flags;

		if (priv->enable_tx_path) {
		int err = priv->enable_tx_path(priv);

		if (err)
		return err;
		}

		/* restart network queue only if echo skb array is free */
		spin_lock_irqsave(&priv->echo_lock, flags);

		if (!priv->can.echo_skb[priv->echo_idx]) {
		spin_unlock_irqrestore(&priv->echo_lock, flags);

		netif_wake_queue(ndev);
		} else {
		spin_unlock_irqrestore(&priv->echo_lock, flags);
		}

		return 0;
		}

		skb = alloc_can_err_skb(ndev, &cf);

		/* test state error bits according to their priority */
		if (pucan_status_is_busoff(msg)) {
		netdev_dbg(ndev, "Bus-off entry status\n");
		priv->can.state = CAN_STATE_BUS_OFF;
		priv->can.can_stats.bus_off++;
		can_bus_off(ndev);
		if (skb)
		cf->can_id \|= CAN_ERR_BUSOFF;

		} else if (pucan_status_is_passive(msg)) {
		netdev_dbg(ndev, "Error passive status\n");
		priv->can.state = CAN_STATE_ERROR_PASSIVE;
		priv->can.can_stats.error_passive++;
		if (skb) {
		cf->can_id \|= CAN_ERR_CRTL;
		cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
		CAN_ERR_CRTL_TX_PASSIVE :
		CAN_ERR_CRTL_RX_PASSIVE;
		cf->data[6] = priv->bec.txerr;
		cf->data[7] = priv->bec.rxerr;
		}

		} else if (pucan_status_is_warning(msg)) {
		netdev_dbg(ndev, "Error warning status\n");
		priv->can.state = CAN_STATE_ERROR_WARNING;
		priv->can.can_stats.error_warning++;
		if (skb) {
		cf->can_id \|= CAN_ERR_CRTL;
		cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
		CAN_ERR_CRTL_TX_WARNING :
		CAN_ERR_CRTL_RX_WARNING;
		cf->data[6] = priv->bec.txerr;
		cf->data[7] = priv->bec.rxerr;
		}

		} else if (priv->can.state != CAN_STATE_ERROR_ACTIVE) {
		/* back to ERROR_ACTIVE */
		netdev_dbg(ndev, "Error active status\n");
		can_change_state(ndev, cf, CAN_STATE_ERROR_ACTIVE,
		CAN_STATE_ERROR_ACTIVE);
		} else {
		dev_kfree_skb(skb);
		return 0;
		}

		if (!skb) {
		stats->rx_dropped++;
		return -ENOMEM;
		}

		stats->rx_packets++;
		stats->rx_bytes += cf->can_dlc;
		netif_rx(skb);

		return 0;
		}

		/* handle uCAN Rx overflow notification */
		static int pucan_handle_cache_critical(struct peak_canfd_priv *priv)
		{
		struct net_device_stats *stats = &priv->ndev->stats;
		struct can_frame *cf;
		struct sk_buff *skb;

		stats->rx_over_errors++;
		stats->rx_errors++;

		skb = alloc_can_err_skb(priv->ndev, &cf);
		if (!skb) {
		stats->rx_dropped++;
		return -ENOMEM;
		}

		cf->can_id \|= CAN_ERR_CRTL;
		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;

		cf->data[6] = priv->bec.txerr;
		cf->data[7] = priv->bec.rxerr;

		stats->rx_bytes += cf->can_dlc;
		stats->rx_packets++;
		netif_rx(skb);

		return 0;
		}

		/* handle a single uCAN message */
		int peak_canfd_handle_msg(struct peak_canfd_priv *priv,
		struct pucan_rx_msg *msg)
		{
		u16 msg_type = le16_to_cpu(msg->type);
		int msg_size = le16_to_cpu(msg->size);
		int err;

		if (!msg_size \|\| !msg_type) {
		/* null packet found: end of list */
		goto exit;
		}

		switch (msg_type) {
		case PUCAN_MSG_CAN_RX:
		err = pucan_handle_can_rx(priv, (struct pucan_rx_msg *)msg);
		break;
		case PUCAN_MSG_ERROR:
		err = pucan_handle_error(priv, (struct pucan_error_msg *)msg);
		break;
		case PUCAN_MSG_STATUS:
		err = pucan_handle_status(priv, (struct pucan_status_msg *)msg);
		break;
		case PUCAN_MSG_CACHE_CRITICAL:
		err = pucan_handle_cache_critical(priv);
		break;
		default:
		err = 0;
		}

		if (err < 0)
		return err;

		exit:
		return msg_size;
		}

		/* handle a list of rx_count messages from rx_msg memory address */
		int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
		struct pucan_rx_msg *msg_list, int msg_count)
		{
		void *msg_ptr = msg_list;
		int i, msg_size;

		for (i = 0; i < msg_count; i++) {
		msg_size = peak_canfd_handle_msg(priv, msg_ptr);

		/* a null packet can be found at the end of a list */
		if (msg_size <= 0)
		break;

		msg_ptr += msg_size;
		}

		if (msg_size < 0)
		return msg_size;

		return i;
		}

		static int peak_canfd_start(struct peak_canfd_priv *priv)
		{
		int err;

		err = pucan_clr_err_counters(priv);
		if (err)
		goto err_exit;

		priv->echo_idx = 0;

		priv->bec.txerr = 0;
		priv->bec.rxerr = 0;

		if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
		err = pucan_set_listen_only_mode(priv);
		else
		err = pucan_set_normal_mode(priv);

		err_exit:
		return err;
		}

		static void peak_canfd_stop(struct peak_canfd_priv *priv)
		{
		int err;

		/* go back to RESET mode */
		err = pucan_set_reset_mode(priv);
		if (err) {
		netdev_err(priv->ndev, "channel %u reset failed\n",
		priv->index);
		} else {
		/* abort last Tx (MUST be done in RESET mode only!) */
		pucan_tx_abort(priv, PUCAN_TX_ABORT_FLUSH);
		}
		}

		static int peak_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);

		switch (mode) {
		case CAN_MODE_START:
		peak_canfd_start(priv);
		netif_wake_queue(ndev);
		break;
		default:
		return -EOPNOTSUPP;
		}

		return 0;
		}

		static int peak_canfd_get_berr_counter(const struct net_device *ndev,
		struct can_berr_counter *bec)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);

		*bec = priv->bec;
		return 0;
		}

		static int peak_canfd_open(struct net_device *ndev)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);
		int i, err = 0;

		err = open_candev(ndev);
		if (err) {
		netdev_err(ndev, "open_candev() failed, error %d\n", err);
		goto err_exit;
		}

		err = pucan_set_reset_mode(priv);
		if (err)
		goto err_close;

		if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
		if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
		err = pucan_clr_options(priv, PUCAN_OPTION_CANDFDISO);
		else
		err = pucan_set_options(priv, PUCAN_OPTION_CANDFDISO);

		if (err)
		goto err_close;
		}

		/* set option: get rx/tx error counters */
		err = pucan_set_options(priv, PUCAN_OPTION_ERROR);
		if (err)
		goto err_close;

		/* accept all standard CAN ID */
		for (i = 0; i <= PUCAN_FLTSTD_ROW_IDX_MAX; i++)
		pucan_set_std_filter(priv, i, 0xffffffff);

		err = peak_canfd_start(priv);
		if (err)
		goto err_close;

		/* receiving the RB status says when Tx path is ready */
		err = pucan_setup_rx_barrier(priv);
		if (!err)
		goto err_exit;

		err_close:
		close_candev(ndev);
		err_exit:
		return err;
		}

		static int peak_canfd_set_bittiming(struct net_device *ndev)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);

		return pucan_set_timing_slow(priv, &priv->can.bittiming);
		}

		static int peak_canfd_set_data_bittiming(struct net_device *ndev)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);

		return pucan_set_timing_fast(priv, &priv->can.data_bittiming);
		}

		static int peak_canfd_close(struct net_device *ndev)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);

		netif_stop_queue(ndev);
		peak_canfd_stop(priv);
		close_candev(ndev);

		return 0;
		}

		static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
		struct net_device *ndev)
		{
		struct peak_canfd_priv *priv = netdev_priv(ndev);
		struct net_device_stats *stats = &ndev->stats;
		struct canfd_frame cf = (struct canfd_frame )skb->data;
		struct pucan_tx_msg *msg;
		u16 msg_size, msg_flags;
		unsigned long flags;
		bool should_stop_tx_queue;
		int room_left;
		u8 can_dlc;

		if (can_dropped_invalid_skb(ndev, skb))
		return NETDEV_TX_OK;

		msg_size = ALIGN(sizeof(*msg) + cf->len, 4);
		msg = priv->alloc_tx_msg(priv, msg_size, &room_left);

		/* should never happen except under bus-off condition and (auto-)restart
		* mechanism
		*/
		if (!msg) {
		stats->tx_dropped++;
		netif_stop_queue(ndev);
		return NETDEV_TX_BUSY;
		}

		msg->size = cpu_to_le16(msg_size);
		msg->type = cpu_to_le16(PUCAN_MSG_CAN_TX);
		msg_flags = 0;

		if (cf->can_id & CAN_EFF_FLAG) {
		msg_flags \|= PUCAN_MSG_EXT_ID;
		msg->can_id = cpu_to_le32(cf->can_id & CAN_EFF_MASK);
		} else {
		msg->can_id = cpu_to_le32(cf->can_id & CAN_SFF_MASK);
		}

		if (can_is_canfd_skb(skb)) {
		/* CAN FD frame format */
		can_dlc = can_len2dlc(cf->len);

		msg_flags \|= PUCAN_MSG_EXT_DATA_LEN;

		if (cf->flags & CANFD_BRS)
		msg_flags \|= PUCAN_MSG_BITRATE_SWITCH;

		if (cf->flags & CANFD_ESI)
		msg_flags \|= PUCAN_MSG_ERROR_STATE_IND;
		} else {
		/* CAN 2.0 frame format */
		can_dlc = cf->len;

		if (cf->can_id & CAN_RTR_FLAG)
		msg_flags \|= PUCAN_MSG_RTR;
		}

		/* always ask loopback for echo management */
		msg_flags \|= PUCAN_MSG_LOOPED_BACK;

		/* set driver specific bit to differentiate with application loopback */
		if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
		msg_flags \|= PUCAN_MSG_SELF_RECEIVE;

		msg->flags = cpu_to_le16(msg_flags);
		msg->channel_dlc = PUCAN_MSG_CHANNEL_DLC(priv->index, can_dlc);
		memcpy(msg->d, cf->data, cf->len);

		/* struct msg client field is used as an index in the echo skbs ring */
		msg->client = priv->echo_idx;

		spin_lock_irqsave(&priv->echo_lock, flags);

		/* prepare and save echo skb in internal slot */
		can_put_echo_skb(skb, ndev, priv->echo_idx);

		/* move echo index to the next slot */
		priv->echo_idx = (priv->echo_idx + 1) % priv->can.echo_skb_max;

		/* if next slot is not free, stop network queue (no slot free in echo
		* skb ring means that the controller did not write these frames on
		* the bus: no need to continue).
		*/
		should_stop_tx_queue = !!(priv->can.echo_skb[priv->echo_idx]);

		spin_unlock_irqrestore(&priv->echo_lock, flags);

		/* write the skb on the interface */
		priv->write_tx_msg(priv, msg);

		/* stop network tx queue if not enough room to save one more msg too */
		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
		should_stop_tx_queue \|= (room_left <
		(sizeof(*msg) + CANFD_MAX_DLEN));
		else
		should_stop_tx_queue \|= (room_left <
		(sizeof(*msg) + CAN_MAX_DLEN));

		if (should_stop_tx_queue)
		netif_stop_queue(ndev);

		return NETDEV_TX_OK;
		}

		static const struct net_device_ops peak_canfd_netdev_ops = {
		.ndo_open = peak_canfd_open,
		.ndo_stop = peak_canfd_close,
		.ndo_start_xmit = peak_canfd_start_xmit,
		.ndo_change_mtu = can_change_mtu,
		};

		struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
		int echo_skb_max)
		{
		struct net_device *ndev;
		struct peak_canfd_priv *priv;

		/* we DO support local echo */
		if (echo_skb_max < 0)
		echo_skb_max = PCANFD_ECHO_SKB_MAX;

		/* allocate the candev object */
		ndev = alloc_candev(sizeof_priv, echo_skb_max);
		if (!ndev)
		return NULL;

		priv = netdev_priv(ndev);

		/* complete now socket-can initialization side */
		priv->can.state = CAN_STATE_STOPPED;
		priv->can.bittiming_const = &peak_canfd_nominal_const;
		priv->can.data_bittiming_const = &peak_canfd_data_const;

		priv->can.do_set_mode = peak_canfd_set_mode;
		priv->can.do_get_berr_counter = peak_canfd_get_berr_counter;
		priv->can.do_set_bittiming = peak_canfd_set_bittiming;
		priv->can.do_set_data_bittiming = peak_canfd_set_data_bittiming;
		priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK \|
		CAN_CTRLMODE_LISTENONLY \|
		CAN_CTRLMODE_3_SAMPLES \|
		CAN_CTRLMODE_FD \|
		CAN_CTRLMODE_FD_NON_ISO \|
		CAN_CTRLMODE_BERR_REPORTING;

		priv->ndev = ndev;
		priv->index = index;
		priv->cmd_len = 0;
		spin_lock_init(&priv->echo_lock);

		ndev->flags \|= IFF_ECHO;
		ndev->netdev_ops = &peak_canfd_netdev_ops;
		ndev->dev_id = index;

		return ndev;
		}