--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/* Nuvoton NCT6694 Socket CANfd driver based on USB interface.
+ *
+ * Copyright (C) 2025 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/can/dev.h>
+#include <linux/can/rx-offload.h>
+#include <linux/ethtool.h>
+#include <linux/idr.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+
+#define DEVICE_NAME "nct6694-canfd"
+
+/* USB command module type for NCT6694 CANfd controller.
+ * This defines the module type used for communication with the NCT6694
+ * CANfd controller over the USB interface.
+ */
+#define NCT6694_CANFD_MOD 0x05
+
+/* Command 00h - CAN Setting and Initialization */
+#define NCT6694_CANFD_SETTING 0x00
+#define NCT6694_CANFD_SETTING_ACTIVE_CTRL1 BIT(0)
+#define NCT6694_CANFD_SETTING_ACTIVE_CTRL2 BIT(1)
+#define NCT6694_CANFD_SETTING_ACTIVE_NBTP_DBTP BIT(2)
+#define NCT6694_CANFD_SETTING_CTRL1_MON BIT(0)
+#define NCT6694_CANFD_SETTING_CTRL1_NISO BIT(1)
+#define NCT6694_CANFD_SETTING_CTRL1_LBCK BIT(2)
+#define NCT6694_CANFD_SETTING_NBTP_NTSEG2 GENMASK(6, 0)
+#define NCT6694_CANFD_SETTING_NBTP_NTSEG1 GENMASK(15, 8)
+#define NCT6694_CANFD_SETTING_NBTP_NBRP GENMASK(24, 16)
+#define NCT6694_CANFD_SETTING_NBTP_NSJW GENMASK(31, 25)
+#define NCT6694_CANFD_SETTING_DBTP_DSJW GENMASK(3, 0)
+#define NCT6694_CANFD_SETTING_DBTP_DTSEG2 GENMASK(7, 4)
+#define NCT6694_CANFD_SETTING_DBTP_DTSEG1 GENMASK(12, 8)
+#define NCT6694_CANFD_SETTING_DBTP_DBRP GENMASK(20, 16)
+#define NCT6694_CANFD_SETTING_DBTP_TDC BIT(23)
+
+/* Command 01h - CAN Information */
+#define NCT6694_CANFD_INFORMATION 0x01
+#define NCT6694_CANFD_INFORMATION_SEL 0x00
+
+/* Command 02h - CAN Event */
+#define NCT6694_CANFD_EVENT 0x02
+#define NCT6694_CANFD_EVENT_SEL(idx, mask) \
+ ((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
+
+#define NCT6694_CANFD_EVENT_MASK GENMASK(5, 0)
+#define NCT6694_CANFD_EVT_TX_FIFO_EMPTY BIT(7) /* Read-clear */
+#define NCT6694_CANFD_EVT_RX_DATA_LOST BIT(5) /* Read-clear */
+#define NCT6694_CANFD_EVT_RX_DATA_IN BIT(7) /* Read-clear */
+
+/* Command 10h - CAN Deliver */
+#define NCT6694_CANFD_DELIVER 0x10
+#define NCT6694_CANFD_DELIVER_SEL(buf_cnt) \
+ ((buf_cnt) & 0xFF)
+
+/* Command 11h - CAN Receive */
+#define NCT6694_CANFD_RECEIVE 0x11
+#define NCT6694_CANFD_RECEIVE_SEL(idx, buf_cnt) \
+ ((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
+
+#define NCT6694_CANFD_FRAME_TAG(idx) (0xC0 | (idx))
+#define NCT6694_CANFD_FRAME_FLAG_EFF BIT(0)
+#define NCT6694_CANFD_FRAME_FLAG_RTR BIT(1)
+#define NCT6694_CANFD_FRAME_FLAG_FD BIT(2)
+#define NCT6694_CANFD_FRAME_FLAG_BRS BIT(3)
+#define NCT6694_CANFD_FRAME_FLAG_ERR BIT(4)
+
+#define NCT6694_NAPI_WEIGHT 32
+
+enum nct6694_event_err {
+ NCT6694_CANFD_EVT_ERR_NO_ERROR = 0,
+ NCT6694_CANFD_EVT_ERR_CRC_ERROR,
+ NCT6694_CANFD_EVT_ERR_STUFF_ERROR,
+ NCT6694_CANFD_EVT_ERR_ACK_ERROR,
+ NCT6694_CANFD_EVT_ERR_FORM_ERROR,
+ NCT6694_CANFD_EVT_ERR_BIT_ERROR,
+ NCT6694_CANFD_EVT_ERR_TIMEOUT_ERROR,
+ NCT6694_CANFD_EVT_ERR_UNKNOWN_ERROR,
+};
+
+enum nct6694_event_status {
+ NCT6694_CANFD_EVT_STS_ERROR_ACTIVE = 0,
+ NCT6694_CANFD_EVT_STS_ERROR_PASSIVE,
+ NCT6694_CANFD_EVT_STS_BUS_OFF,
+ NCT6694_CANFD_EVT_STS_WARNING,
+};
+
+struct __packed nct6694_canfd_setting {
+ __le32 nbr;
+ __le32 dbr;
+ u8 active;
+ u8 reserved[3];
+ __le16 ctrl1;
+ __le16 ctrl2;
+ __le32 nbtp;
+ __le32 dbtp;
+};
+
+struct __packed nct6694_canfd_information {
+ u8 tx_fifo_cnt;
+ u8 rx_fifo_cnt;
+ u8 reserved[2];
+ __le32 can_clk;
+};
+
+struct __packed nct6694_canfd_event {
+ u8 err;
+ u8 status;
+ u8 tx_evt;
+ u8 rx_evt;
+ u8 rec;
+ u8 tec;
+ u8 reserved[2];
+};
+
+struct __packed nct6694_canfd_frame {
+ u8 tag;
+ u8 flag;
+ u8 reserved;
+ u8 length;
+ __le32 id;
+ u8 data[CANFD_MAX_DLEN];
+};
+
+struct nct6694_canfd_priv {
+ struct can_priv can; /* must be the first member */
+ struct can_rx_offload offload;
+ struct net_device *ndev;
+ struct nct6694 *nct6694;
+ struct workqueue_struct *wq;
+ struct work_struct tx_work;
+ struct nct6694_canfd_frame tx;
+ struct nct6694_canfd_frame rx;
+ struct nct6694_canfd_event event[2];
+ struct can_berr_counter bec;
+};
+
+static inline struct nct6694_canfd_priv *rx_offload_to_priv(struct can_rx_offload *offload)
+{
+ return container_of(offload, struct nct6694_canfd_priv, offload);
+}
+
+static const struct can_bittiming_const nct6694_canfd_bittiming_nominal_const = {
+ .name = DEVICE_NAME,
+ .tseg1_min = 1,
+ .tseg1_max = 256,
+ .tseg2_min = 1,
+ .tseg2_max = 128,
+ .sjw_max = 128,
+ .brp_min = 1,
+ .brp_max = 512,
+ .brp_inc = 1,
+};
+
+static const struct can_bittiming_const nct6694_canfd_bittiming_data_const = {
+ .name = DEVICE_NAME,
+ .tseg1_min = 1,
+ .tseg1_max = 32,
+ .tseg2_min = 1,
+ .tseg2_max = 16,
+ .sjw_max = 16,
+ .brp_min = 1,
+ .brp_max = 32,
+ .brp_inc = 1,
+};
+
+static void nct6694_canfd_rx_offload(struct can_rx_offload *offload,
+ struct sk_buff *skb)
+{
+ struct nct6694_canfd_priv *priv = rx_offload_to_priv(offload);
+ int ret;
+
+ ret = can_rx_offload_queue_tail(offload, skb);
+ if (ret)
+ priv->ndev->stats.rx_fifo_errors++;
+}
+
+static void nct6694_canfd_handle_lost_msg(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ netdev_dbg(ndev, "RX FIFO overflow, message(s) lost.\n");
+
+ stats->rx_errors++;
+ stats->rx_over_errors++;
+
+ skb = alloc_can_err_skb(ndev, &cf);
+ if (!skb)
+ return;
+
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+ nct6694_canfd_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_canfd_handle_rx(struct net_device *ndev, u8 rx_evt)
+{
+ struct net_device_stats *stats = &ndev->stats;
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_canfd_frame *frame = &priv->rx;
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_RECEIVE,
+ .sel = NCT6694_CANFD_RECEIVE_SEL(ndev->dev_port, 1),
+ .len = cpu_to_le16(sizeof(*frame))
+ };
+ struct sk_buff *skb;
+ int ret;
+
+ ret = nct6694_read_msg(priv->nct6694, &cmd_hd, frame);
+ if (ret)
+ return;
+
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_FD) {
+ struct canfd_frame *cfd;
+
+ skb = alloc_canfd_skb(priv->ndev, &cfd);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cfd->can_id = le32_to_cpu(frame->id);
+ cfd->len = canfd_sanitize_len(frame->length);
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_EFF)
+ cfd->can_id |= CAN_EFF_FLAG;
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_BRS)
+ cfd->flags |= CANFD_BRS;
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_ERR)
+ cfd->flags |= CANFD_ESI;
+
+ memcpy(cfd->data, frame->data, cfd->len);
+ } else {
+ struct can_frame *cf;
+
+ skb = alloc_can_skb(priv->ndev, &cf);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cf->can_id = le32_to_cpu(frame->id);
+ cf->len = can_cc_dlc2len(frame->length);
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_EFF)
+ cf->can_id |= CAN_EFF_FLAG;
+
+ if (frame->flag & NCT6694_CANFD_FRAME_FLAG_RTR)
+ cf->can_id |= CAN_RTR_FLAG;
+ else
+ memcpy(cf->data, frame->data, cf->len);
+ }
+
+ nct6694_canfd_rx_offload(&priv->offload, skb);
+}
+
+static int nct6694_canfd_get_berr_counter(const struct net_device *ndev,
+ struct can_berr_counter *bec)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+
+ *bec = priv->bec;
+
+ return 0;
+}
+
+static void nct6694_canfd_handle_state_change(struct net_device *ndev, u8 status)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ enum can_state new_state, rx_state, tx_state;
+ struct can_berr_counter bec;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ nct6694_canfd_get_berr_counter(ndev, &bec);
+ can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);
+
+ new_state = max(tx_state, rx_state);
+
+ /* state hasn't changed */
+ if (new_state == priv->can.state)
+ return;
+
+ skb = alloc_can_err_skb(ndev, &cf);
+
+ can_change_state(ndev, cf, tx_state, rx_state);
+
+ if (new_state == CAN_STATE_BUS_OFF) {
+ can_bus_off(ndev);
+ } else if (cf) {
+ cf->can_id |= CAN_ERR_CNT;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ }
+
+ if (skb)
+ nct6694_canfd_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_canfd_handle_bus_err(struct net_device *ndev, u8 bus_err)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ priv->can.can_stats.bus_error++;
+
+ skb = alloc_can_err_skb(ndev, &cf);
+ if (cf)
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ switch (bus_err) {
+ case NCT6694_CANFD_EVT_ERR_CRC_ERROR:
+ netdev_dbg(ndev, "CRC error\n");
+ ndev->stats.rx_errors++;
+ if (cf)
+ cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+ break;
+
+ case NCT6694_CANFD_EVT_ERR_STUFF_ERROR:
+ netdev_dbg(ndev, "Stuff error\n");
+ ndev->stats.rx_errors++;
+ if (cf)
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+
+ case NCT6694_CANFD_EVT_ERR_ACK_ERROR:
+ netdev_dbg(ndev, "Ack error\n");
+ ndev->stats.tx_errors++;
+ if (cf) {
+ cf->can_id |= CAN_ERR_ACK;
+ cf->data[2] |= CAN_ERR_PROT_TX;
+ }
+ break;
+
+ case NCT6694_CANFD_EVT_ERR_FORM_ERROR:
+ netdev_dbg(ndev, "Form error\n");
+ ndev->stats.rx_errors++;
+ if (cf)
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+
+ case NCT6694_CANFD_EVT_ERR_BIT_ERROR:
+ netdev_dbg(ndev, "Bit error\n");
+ ndev->stats.tx_errors++;
+ if (cf)
+ cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
+ break;
+
+ default:
+ break;
+ }
+
+ if (skb)
+ nct6694_canfd_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_canfd_handle_tx(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+
+ stats->tx_bytes += can_rx_offload_get_echo_skb_queue_tail(&priv->offload,
+ 0, NULL);
+ stats->tx_packets++;
+ netif_wake_queue(ndev);
+}
+
+static irqreturn_t nct6694_canfd_irq(int irq, void *data)
+{
+ struct net_device *ndev = data;
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_canfd_event *event = &priv->event[ndev->dev_port];
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_EVENT,
+ .sel = NCT6694_CANFD_EVENT_SEL(ndev->dev_port, NCT6694_CANFD_EVENT_MASK),
+ .len = cpu_to_le16(sizeof(priv->event))
+ };
+ irqreturn_t handled = IRQ_NONE;
+ int ret;
+
+ ret = nct6694_read_msg(priv->nct6694, &cmd_hd, priv->event);
+ if (ret < 0)
+ return handled;
+
+ if (event->rx_evt & NCT6694_CANFD_EVT_RX_DATA_IN) {
+ nct6694_canfd_handle_rx(ndev, event->rx_evt);
+ handled = IRQ_HANDLED;
+ }
+
+ if (event->rx_evt & NCT6694_CANFD_EVT_RX_DATA_LOST) {
+ nct6694_canfd_handle_lost_msg(ndev);
+ handled = IRQ_HANDLED;
+ }
+
+ if (event->status) {
+ nct6694_canfd_handle_state_change(ndev, event->status);
+ handled = IRQ_HANDLED;
+ }
+
+ if (event->err != NCT6694_CANFD_EVT_ERR_NO_ERROR) {
+ if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+ nct6694_canfd_handle_bus_err(ndev, event->err);
+ handled = IRQ_HANDLED;
+ }
+
+ if (event->tx_evt & NCT6694_CANFD_EVT_TX_FIFO_EMPTY) {
+ nct6694_canfd_handle_tx(ndev);
+ handled = IRQ_HANDLED;
+ }
+
+ if (handled)
+ can_rx_offload_threaded_irq_finish(&priv->offload);
+
+ priv->bec.rxerr = event->rec;
+ priv->bec.txerr = event->tec;
+
+ return handled;
+}
+
+static void nct6694_canfd_tx_work(struct work_struct *work)
+{
+ struct nct6694_canfd_priv *priv = container_of(work,
+ struct nct6694_canfd_priv,
+ tx_work);
+ struct nct6694_canfd_frame *frame = &priv->tx;
+ struct net_device *ndev = priv->ndev;
+ struct net_device_stats *stats = &ndev->stats;
+ struct sk_buff *skb = priv->can.echo_skb[0];
+ static const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_DELIVER,
+ .sel = NCT6694_CANFD_DELIVER_SEL(1),
+ .len = cpu_to_le16(sizeof(*frame))
+ };
+ u32 txid;
+ int err;
+
+ memset(frame, 0, sizeof(*frame));
+
+ frame->tag = NCT6694_CANFD_FRAME_TAG(ndev->dev_port);
+
+ if (can_is_canfd_skb(skb)) {
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (cfd->flags & CANFD_BRS)
+ frame->flag |= NCT6694_CANFD_FRAME_FLAG_BRS;
+
+ if (cfd->can_id & CAN_EFF_FLAG) {
+ txid = cfd->can_id & CAN_EFF_MASK;
+ frame->flag |= NCT6694_CANFD_FRAME_FLAG_EFF;
+ } else {
+ txid = cfd->can_id & CAN_SFF_MASK;
+ }
+ frame->flag |= NCT6694_CANFD_FRAME_FLAG_FD;
+ frame->id = cpu_to_le32(txid);
+ frame->length = canfd_sanitize_len(cfd->len);
+
+ memcpy(frame->data, cfd->data, frame->length);
+ } else {
+ struct can_frame *cf = (struct can_frame *)skb->data;
+
+ if (cf->can_id & CAN_EFF_FLAG) {
+ txid = cf->can_id & CAN_EFF_MASK;
+ frame->flag |= NCT6694_CANFD_FRAME_FLAG_EFF;
+ } else {
+ txid = cf->can_id & CAN_SFF_MASK;
+ }
+
+ if (cf->can_id & CAN_RTR_FLAG)
+ frame->flag |= NCT6694_CANFD_FRAME_FLAG_RTR;
+ else
+ memcpy(frame->data, cf->data, cf->len);
+
+ frame->id = cpu_to_le32(txid);
+ frame->length = cf->len;
+ }
+
+ err = nct6694_write_msg(priv->nct6694, &cmd_hd, frame);
+ if (err) {
+ can_free_echo_skb(ndev, 0, NULL);
+ stats->tx_dropped++;
+ stats->tx_errors++;
+ netif_wake_queue(ndev);
+ }
+}
+
+static netdev_tx_t nct6694_canfd_start_xmit(struct sk_buff *skb,
+ struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+
+ if (can_dev_dropped_skb(ndev, skb))
+ return NETDEV_TX_OK;
+
+ netif_stop_queue(ndev);
+ can_put_echo_skb(skb, ndev, 0, 0);
+ queue_work(priv->wq, &priv->tx_work);
+
+ return NETDEV_TX_OK;
+}
+
+static int nct6694_canfd_start(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ const struct can_bittiming *n_bt = &priv->can.bittiming;
+ const struct can_bittiming *d_bt = &priv->can.fd.data_bittiming;
+ struct nct6694_canfd_setting *setting __free(kfree) = NULL;
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_SETTING,
+ .sel = ndev->dev_port,
+ .len = cpu_to_le16(sizeof(*setting))
+ };
+ u32 en_tdc;
+ int ret;
+
+ setting = kzalloc(sizeof(*setting), GFP_KERNEL);
+ if (!setting)
+ return -ENOMEM;
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_MON);
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_NISO);
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_LBCK);
+
+ /* Disable clock divider */
+ setting->ctrl2 = 0;
+
+ setting->nbtp = cpu_to_le32(FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NSJW,
+ n_bt->sjw - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NBRP,
+ n_bt->brp - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NTSEG2,
+ n_bt->phase_seg2 - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_NBTP_NTSEG1,
+ n_bt->prop_seg + n_bt->phase_seg1 - 1));
+
+ if (d_bt->brp <= 2)
+ en_tdc = NCT6694_CANFD_SETTING_DBTP_TDC;
+ else
+ en_tdc = 0;
+
+ setting->dbtp = cpu_to_le32(FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DSJW,
+ d_bt->sjw - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DBRP,
+ d_bt->brp - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DTSEG2,
+ d_bt->phase_seg2 - 1) |
+ FIELD_PREP(NCT6694_CANFD_SETTING_DBTP_DTSEG1,
+ d_bt->prop_seg + d_bt->phase_seg1 - 1) |
+ en_tdc);
+
+ setting->active = NCT6694_CANFD_SETTING_ACTIVE_CTRL1 |
+ NCT6694_CANFD_SETTING_ACTIVE_CTRL2 |
+ NCT6694_CANFD_SETTING_ACTIVE_NBTP_DBTP;
+
+ ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
+ if (ret)
+ return ret;
+
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ return 0;
+}
+
+static void nct6694_canfd_stop(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_canfd_setting *setting __free(kfree) = NULL;
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_SETTING,
+ .sel = ndev->dev_port,
+ .len = cpu_to_le16(sizeof(*setting))
+ };
+
+ /* The NCT6694 cannot be stopped. To ensure safe operation and avoid
+ * interference, the control mode is set to Listen-Only mode. This
+ * mode allows the device to monitor bus activity without actively
+ * participating in communication.
+ */
+ setting = kzalloc(sizeof(*setting), GFP_KERNEL);
+ if (!setting)
+ return;
+
+ nct6694_read_msg(priv->nct6694, &cmd_hd, setting);
+ setting->ctrl1 = cpu_to_le16(NCT6694_CANFD_SETTING_CTRL1_MON);
+ setting->active = NCT6694_CANFD_SETTING_ACTIVE_CTRL1;
+ nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
+
+ priv->can.state = CAN_STATE_STOPPED;
+}
+
+static int nct6694_canfd_close(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ nct6694_canfd_stop(ndev);
+ destroy_workqueue(priv->wq);
+ free_irq(ndev->irq, ndev);
+ can_rx_offload_disable(&priv->offload);
+ close_candev(ndev);
+ return 0;
+}
+
+static int nct6694_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+ int ret;
+
+ switch (mode) {
+ case CAN_MODE_START:
+ ret = nct6694_canfd_start(ndev);
+ if (ret)
+ return ret;
+
+ netif_wake_queue(ndev);
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return ret;
+}
+
+static int nct6694_canfd_open(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ int ret;
+
+ ret = open_candev(ndev);
+ if (ret)
+ return ret;
+
+ can_rx_offload_enable(&priv->offload);
+
+ ret = request_threaded_irq(ndev->irq, NULL,
+ nct6694_canfd_irq, IRQF_ONESHOT,
+ "nct6694_canfd", ndev);
+ if (ret) {
+ netdev_err(ndev, "Failed to request IRQ\n");
+ goto can_rx_offload_disable;
+ }
+
+ priv->wq = alloc_ordered_workqueue("%s-nct6694_wq",
+ WQ_FREEZABLE | WQ_MEM_RECLAIM,
+ ndev->name);
+ if (!priv->wq) {
+ ret = -ENOMEM;
+ goto free_irq;
+ }
+
+ ret = nct6694_canfd_start(ndev);
+ if (ret)
+ goto destroy_wq;
+
+ netif_start_queue(ndev);
+
+ return 0;
+
+destroy_wq:
+ destroy_workqueue(priv->wq);
+free_irq:
+ free_irq(ndev->irq, ndev);
+can_rx_offload_disable:
+ can_rx_offload_disable(&priv->offload);
+ close_candev(ndev);
+ return ret;
+}
+
+static const struct net_device_ops nct6694_canfd_netdev_ops = {
+ .ndo_open = nct6694_canfd_open,
+ .ndo_stop = nct6694_canfd_close,
+ .ndo_start_xmit = nct6694_canfd_start_xmit,
+ .ndo_change_mtu = can_change_mtu,
+};
+
+static const struct ethtool_ops nct6694_canfd_ethtool_ops = {
+ .get_ts_info = ethtool_op_get_ts_info,
+};
+
+static int nct6694_canfd_get_clock(struct nct6694_canfd_priv *priv)
+{
+ struct nct6694_canfd_information *info __free(kfree) = NULL;
+ static const struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CANFD_MOD,
+ .cmd = NCT6694_CANFD_INFORMATION,
+ .sel = NCT6694_CANFD_INFORMATION_SEL,
+ .len = cpu_to_le16(sizeof(*info))
+ };
+ int ret;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ ret = nct6694_read_msg(priv->nct6694, &cmd_hd, info);
+ if (ret)
+ return ret;
+
+ return le32_to_cpu(info->can_clk);
+}
+
+static int nct6694_canfd_probe(struct platform_device *pdev)
+{
+ struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+ struct nct6694_canfd_priv *priv;
+ struct net_device *ndev;
+ int port, irq, ret, can_clk;
+
+ port = ida_alloc(&nct6694->canfd_ida, GFP_KERNEL);
+ if (port < 0)
+ return port;
+
+ irq = irq_create_mapping(nct6694->domain,
+ NCT6694_IRQ_CAN0 + port);
+ if (!irq) {
+ ret = -EINVAL;
+ goto free_ida;
+ }
+
+ ndev = alloc_candev(sizeof(struct nct6694_canfd_priv), 1);
+ if (!ndev) {
+ ret = -ENOMEM;
+ goto dispose_irq;
+ }
+
+ ndev->irq = irq;
+ ndev->flags |= IFF_ECHO;
+ ndev->dev_port = port;
+ ndev->netdev_ops = &nct6694_canfd_netdev_ops;
+ ndev->ethtool_ops = &nct6694_canfd_ethtool_ops;
+
+ priv = netdev_priv(ndev);
+ priv->nct6694 = nct6694;
+ priv->ndev = ndev;
+
+ can_clk = nct6694_canfd_get_clock(priv);
+ if (can_clk < 0) {
+ ret = dev_err_probe(&pdev->dev, can_clk,
+ "Failed to get clock\n");
+ goto free_candev;
+ }
+
+ INIT_WORK(&priv->tx_work, nct6694_canfd_tx_work);
+
+ priv->can.clock.freq = can_clk;
+ priv->can.bittiming_const = &nct6694_canfd_bittiming_nominal_const;
+ priv->can.fd.data_bittiming_const = &nct6694_canfd_bittiming_data_const;
+ priv->can.do_set_mode = nct6694_canfd_set_mode;
+ priv->can.do_get_berr_counter = nct6694_canfd_get_berr_counter;
+ priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+ CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
+ CAN_CTRLMODE_FD_NON_ISO;
+
+ ret = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
+ if (ret)
+ goto free_candev;
+
+ ret = can_rx_offload_add_manual(ndev, &priv->offload,
+ NCT6694_NAPI_WEIGHT);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
+ goto free_candev;
+ }
+
+ platform_set_drvdata(pdev, priv);
+ SET_NETDEV_DEV(priv->ndev, &pdev->dev);
+
+ ret = register_candev(priv->ndev);
+ if (ret)
+ goto rx_offload_del;
+
+ return 0;
+
+rx_offload_del:
+ can_rx_offload_del(&priv->offload);
+free_candev:
+ free_candev(ndev);
+dispose_irq:
+ irq_dispose_mapping(irq);
+free_ida:
+ ida_free(&nct6694->canfd_ida, port);
+ return ret;
+}
+
+static void nct6694_canfd_remove(struct platform_device *pdev)
+{
+ struct nct6694_canfd_priv *priv = platform_get_drvdata(pdev);
+ struct nct6694 *nct6694 = priv->nct6694;
+ struct net_device *ndev = priv->ndev;
+ int port = ndev->dev_port;
+ int irq = ndev->irq;
+
+ unregister_candev(ndev);
+ can_rx_offload_del(&priv->offload);
+ free_candev(ndev);
+ irq_dispose_mapping(irq);
+ ida_free(&nct6694->canfd_ida, port);
+}
+
+static struct platform_driver nct6694_canfd_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ },
+ .probe = nct6694_canfd_probe,
+ .remove = nct6694_canfd_remove,
+};
+
+module_platform_driver(nct6694_canfd_driver);
+
+MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
projects / thirdparty / kernel / stable.git / commitdiff
