[PATCH v6 4/7] can: Add Nuvoton NCT6694 CANFD support

Ming Yu
2025-01-23T09:12:01Z

This driver supports Socket CANFD functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
MAINTAINERS | 1 +
drivers/net/can/usb/Kconfig | 11 +
drivers/net/can/usb/Makefile | 1 +
drivers/net/can/usb/nct6694_canfd.c | 813 ++++++++++++++++++++++++++++
4 files changed, 826 insertions(+)
create mode 100644 drivers/net/can/usb/nct6694_canfd.c

diff --git a/MAINTAINERS b/MAINTAINERS
index f930252ad132..3196f87c547d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16808,6 +16808,7 @@ S: Supported
F: drivers/gpio/gpio-nct6694.c
F: drivers/i2c/busses/i2c-nct6694.c
F: drivers/mfd/nct6694.c
+F: drivers/net/can/usb/nct6694_canfd.c
F: include/linux/mfd/nct6694.h

NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index 9dae0c71a2e1..759e724a67cf 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -133,6 +133,17 @@ config CAN_MCBA_USB
This driver supports the CAN BUS Analyzer interface
from Microchip (http://www.microchip.com/development-tools/).

+config CAN_NCT6694
+ tristate "Nuvoton NCT6694 Socket CANfd support"
+ depends on MFD_NCT6694
+ select CAN_RX_OFFLOAD
+ help
+ If you say yes to this option, support will be included for Nuvoton
+ NCT6694, a USB device to socket CANfd controller.
+
+ This driver can also be built as a module. If so, the module will
+ be called nct6694_canfd.
+
config CAN_PEAK_USB
tristate "PEAK PCAN-USB/USB Pro interfaces for CAN 2.0b/CAN-FD"
help
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index 8b11088e9a59..fcafb1ac262e 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -11,5 +11,6 @@ obj-$(CONFIG_CAN_F81604) += f81604.o
obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb/
obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
+obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
obj-$(CONFIG_CAN_UCAN) += ucan.o
diff --git a/drivers/net/can/usb/nct6694_canfd.c b/drivers/net/can/usb/nct6694_canfd.c
new file mode 100644
index 000000000000..56d729b438f3
--- /dev/null
+++ b/drivers/net/can/usb/nct6694_canfd.c
@@ -0,0 +1,813 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 Socket CANfd driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/can/dev.h>
+#include <linux/can/rx-offload.h>
+#include <linux/ethtool.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+
+#define DRVNAME "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_CAN_MOD 0x05
+
+/* Command 00h - CAN Setting and Initialization */
+#define NCT6694_CAN_SETTING 0x00
+#define NCT6694_CAN_SETTING_CTRL1_MON BIT(0)
+#define NCT6694_CAN_SETTING_CTRL1_NISO BIT(1)
+#define NCT6694_CAN_SETTING_CTRL1_LBCK BIT(2)
+
+/* Command 01h - CAN Information */
+#define NCT6694_CAN_INFORMATION 0x01
+#define NCT6694_CAN_INFORMATION_SEL 0x00
+
+/* Command 02h - CAN Event */
+#define NCT6694_CAN_EVENT 0x02
+#define NCT6694_CAN_EVENT_SEL(idx, mask) \
+ ((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
+
+#define NCT6694_CAN_EVENT_MASK GENMASK(5, 0)
+#define NCT6694_CAN_EVT_TX_FIFO_EMPTY BIT(7) /* Read-clear */
+#define NCT6694_CAN_EVT_RX_DATA_LOST BIT(5) /* Read-clear */
+#define NCT6694_CAN_EVT_RX_DATA_IN BIT(7) /* Read-clear*/
+
+/* Command 10h - CAN Deliver */
+#define NCT6694_CAN_DELIVER 0x10
+#define NCT6694_CAN_DELIVER_SEL(buf_cnt) \
+ ((buf_cnt) & 0xFF)
+
+/* Command 11h - CAN Receive */
+#define NCT6694_CAN_RECEIVE 0x11
+#define NCT6694_CAN_RECEIVE_SEL(idx, buf_cnt) \
+ ((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
+
+#define NCT6694_CAN_FRAME_TAG_CAN0 0xC0
+#define NCT6694_CAN_FRAME_TAG_CAN1 0xC1
+#define NCT6694_CAN_FRAME_FLAG_EFF BIT(0)
+#define NCT6694_CAN_FRAME_FLAG_RTR BIT(1)
+#define NCT6694_CAN_FRAME_FLAG_FD BIT(2)
+#define NCT6694_CAN_FRAME_FLAG_BRS BIT(3)
+#define NCT6694_CAN_FRAME_FLAG_ERR BIT(4)
+
+#define NCT6694_NAPI_WEIGHT 32
+
+enum nct6694_event_err {
+ NCT6694_CAN_EVT_ERR_NO_ERROR = 0,
+ NCT6694_CAN_EVT_ERR_CRC_ERROR,
+ NCT6694_CAN_EVT_ERR_STUFF_ERROR,
+ NCT6694_CAN_EVT_ERR_ACK_ERROR,
+ NCT6694_CAN_EVT_ERR_FORM_ERROR,
+ NCT6694_CAN_EVT_ERR_BIT_ERROR,
+ NCT6694_CAN_EVT_ERR_TIMEOUT_ERROR,
+ NCT6694_CAN_EVT_ERR_UNKNOWN_ERROR,
+};
+
+enum nct6694_event_status {
+ NCT6694_CAN_EVT_STS_ERROR_ACTIVE = 0,
+ NCT6694_CAN_EVT_STS_ERROR_PASSIVE,
+ NCT6694_CAN_EVT_STS_BUS_OFF,
+ NCT6694_CAN_EVT_STS_WARNING,
+};
+
+struct __packed nct6694_can_setting {
+ __le32 nbr;
+ __le32 dbr;
+ u8 active;
+ u8 reserved[3];
+ __le16 ctrl1;
+ __le16 ctrl2;
+ __le32 nbtp;
+ __le32 dbtp;
+};
+
+struct __packed nct6694_can_information {
+ u8 tx_fifo_cnt;
+ u8 rx_fifo_cnt;
+ u8 reserved[2];
+ __le32 can_clk;
+};
+
+struct __packed nct6694_can_event {
+ u8 err;
+ u8 status;
+ u8 tx_evt;
+ u8 rx_evt;
+ u8 rec;
+ u8 tec;
+ u8 reserved[2];
+};
+
+struct __packed nct6694_can_frame {
+ u8 tag;
+ u8 flag;
+ u8 reserved;
+ u8 length;
+ __le32 id;
+ u8 data[CANFD_MAX_DLEN];
+};
+
+struct nct6694_can_priv {
+ struct can_priv can; /* must be the first member */
+ struct can_rx_offload offload;
+ struct can_berr_counter bec;
+ struct net_device *ndev;
+ struct nct6694 *nct6694;
+ struct workqueue_struct *wq;
+ struct work_struct tx_work;
+ struct nct6694_can_frame tx;
+ struct nct6694_can_frame rx;
+ struct nct6694_can_event event[2];
+ unsigned char can_idx;
+};
+
+static inline struct nct6694_can_priv *rx_offload_to_priv(struct can_rx_offload *offload)
+{
+ return container_of(offload, struct nct6694_can_priv, offload);
+}
+
+static const struct can_bittiming_const nct6694_can_bittiming_nominal_const = {
+ .name = DRVNAME,
+ .tseg1_min = 2,
+ .tseg1_max = 256,
+ .tseg2_min = 2,
+ .tseg2_max = 128,
+ .sjw_max = 128,
+ .brp_min = 1,
+ .brp_max = 511,
+ .brp_inc = 1,
+};
+
+static const struct can_bittiming_const nct6694_can_bittiming_data_const = {
+ .name = DRVNAME,
+ .tseg1_min = 1,
+ .tseg1_max = 32,
+ .tseg2_min = 1,
+ .tseg2_max = 16,
+ .sjw_max = 16,
+ .brp_min = 1,
+ .brp_max = 31,
+ .brp_inc = 1,
+};
+
+static void nct6694_can_rx_offload(struct can_rx_offload *offload,
+ struct sk_buff *skb)
+{
+ struct nct6694_can_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_can_handle_lost_msg(struct net_device *ndev)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ netdev_err(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_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_rx(struct net_device *ndev, u8 rx_evt)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_frame *frame = &priv->rx;
+ struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CAN_MOD,
+ .cmd = NCT6694_CAN_RECEIVE,
+ .sel = NCT6694_CAN_RECEIVE_SEL(priv->can_idx, 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_CAN_FRAME_FLAG_FD) {
+ struct canfd_frame *cfd;
+
+ skb = alloc_canfd_skb(priv->ndev, &cfd);
+ if (!skb)
+ return;
+
+ cfd->can_id = le32_to_cpu(frame->id);
+ cfd->len = canfd_sanitize_len(frame->length);
+ if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
+ cfd->can_id |= CAN_EFF_FLAG;
+ if (frame->flag & NCT6694_CAN_FRAME_FLAG_BRS)
+ cfd->flags |= CANFD_BRS;
+ if (frame->flag & NCT6694_CAN_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)
+ return;
+
+ cf->can_id = le32_to_cpu(frame->id);
+ cf->len = canfd_sanitize_len(frame->length);
+ if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
+ cf->can_id |= CAN_EFF_FLAG;
+
+ if (frame->flag & NCT6694_CAN_FRAME_FLAG_RTR)
+ cf->can_id |= CAN_RTR_FLAG;
+ else
+ memcpy(cf->data, frame->data, cf->len);
+ }
+
+ nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static int nct6694_can_get_berr_counter(const struct net_device *ndev,
+ struct can_berr_counter *bec)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+ bec->txerr = priv->bec.txerr;
+ bec->rxerr = priv->bec.rxerr;
+
+ return 0;
+}
+
+static void nct6694_can_handle_state_change(struct net_device *ndev,
+ enum can_state new_state)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct can_berr_counter bec;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ switch (new_state) {
+ case CAN_STATE_ERROR_ACTIVE:
+ priv->can.can_stats.error_warning++;
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ break;
+ case CAN_STATE_ERROR_WARNING:
+ priv->can.can_stats.error_warning++;
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ break;
+ case CAN_STATE_ERROR_PASSIVE:
+ priv->can.can_stats.error_passive++;
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ break;
+ case CAN_STATE_BUS_OFF:
+ priv->can.state = CAN_STATE_BUS_OFF;
+ priv->can.can_stats.bus_off++;
+ can_free_echo_skb(ndev, 0, NULL);
+ netif_stop_queue(ndev);
+ can_bus_off(ndev);
+ break;
+ default:
+ break;
+ }
+
+ skb = alloc_can_err_skb(ndev, &cf);
+
+ nct6694_can_get_berr_counter(ndev, &bec);
+
+ switch (new_state) {
+ case CAN_STATE_ERROR_WARNING:
+ cf->can_id |= CAN_ERR_CRTL;
+ if (bec.txerr > bec.rxerr)
+ cf->data[1] = CAN_ERR_CRTL_TX_WARNING;
+ else
+ cf->data[1] = CAN_ERR_CRTL_RX_WARNING;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ break;
+ case CAN_STATE_ERROR_PASSIVE:
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
+ if (bec.txerr > 127)
+ cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ break;
+ case CAN_STATE_BUS_OFF:
+ cf->can_id |= CAN_ERR_BUSOFF;
+ break;
+ default:
+ break;
+ }
+
+ nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+ if (status == NCT6694_CAN_EVT_STS_ERROR_ACTIVE &&
+ priv->can.state != CAN_STATE_ERROR_ACTIVE) {
+ netdev_dbg(ndev, "Error, entered active state\n");
+ nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_ACTIVE);
+ }
+
+ if (status == NCT6694_CAN_EVT_STS_WARNING &&
+ priv->can.state != CAN_STATE_ERROR_WARNING) {
+ netdev_dbg(ndev, "Error, entered warning state\n");
+ nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_WARNING);
+ }
+
+ if (status == NCT6694_CAN_EVT_STS_ERROR_PASSIVE &&
+ priv->can.state != CAN_STATE_ERROR_PASSIVE) {
+ netdev_dbg(ndev, "Error, entered passive state\n");
+ nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_PASSIVE);
+ }
+
+ if (status == NCT6694_CAN_EVT_STS_BUS_OFF &&
+ priv->can.state != CAN_STATE_BUS_OFF) {
+ netdev_dbg(ndev, "Error, entered bus-off state\n");
+ nct6694_can_handle_state_change(ndev, CAN_STATE_BUS_OFF);
+ }
+}
+
+static void nct6694_can_handle_bus_err(struct net_device *ndev, u8 bus_err)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ if (bus_err == NCT6694_CAN_EVT_ERR_NO_ERROR)
+ return;
+
+ priv->can.can_stats.bus_error++;
+
+ skb = alloc_can_err_skb(ndev, &cf);
+ if (skb)
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ switch (bus_err) {
+ case NCT6694_CAN_EVT_ERR_CRC_ERROR:
+ netdev_dbg(ndev, "CRC error\n");
+ ndev->stats.rx_errors++;
+ if (skb)
+ cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+ break;
+
+ case NCT6694_CAN_EVT_ERR_STUFF_ERROR:
+ netdev_dbg(ndev, "Stuff error\n");
+ ndev->stats.rx_errors++;
+ if (skb)
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+
+ case NCT6694_CAN_EVT_ERR_ACK_ERROR:
+ netdev_dbg(ndev, "Ack error\n");
+ ndev->stats.tx_errors++;
+ if (skb) {
+ cf->can_id |= CAN_ERR_ACK;
+ cf->data[2] |= CAN_ERR_PROT_TX;
+ }
+ break;
+
+ case NCT6694_CAN_EVT_ERR_FORM_ERROR:
+ netdev_dbg(ndev, "Form error\n");
+ ndev->stats.rx_errors++;
+ if (skb)
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+
+ case NCT6694_CAN_EVT_ERR_BIT_ERROR:
+ netdev_dbg(ndev, "Bit error\n");
+ ndev->stats.tx_errors++;
+ if (skb)
+ cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
+ break;
+
+ default:
+ break;
+ }
+
+ nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_tx_irq(struct net_device *ndev)
+{
+ struct net_device_stats *stats = &ndev->stats;
+
+ stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
+ stats->tx_packets++;
+ netif_wake_queue(ndev);
+}
+
+static irqreturn_t nct6694_can_irq(int irq, void *data)
+{
+ struct net_device *ndev = data;
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_event *evt = priv->event;
+ struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CAN_MOD,
+ .cmd = NCT6694_CAN_EVENT,
+ .sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
+ .len = cpu_to_le16(sizeof(priv->event))
+ };
+ irqreturn_t handled = IRQ_NONE;
+ int can_idx = priv->can_idx;
+ int ret;
+
+ ret = nct6694_read_msg(priv->nct6694, &cmd_hd, evt);
+ if (ret < 0)
+ return handled;
+
+ if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) {
+ nct6694_can_rx(ndev, priv->event[can_idx].rx_evt);
+ handled = IRQ_HANDLED;
+ }
+
+ if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) {
+ nct6694_can_handle_lost_msg(ndev);
+ handled = IRQ_HANDLED;
+ }
+
+ if (priv->event[can_idx].status) {
+ nct6694_can_handle_state_errors(ndev, priv->event[can_idx].status);
+ handled = IRQ_HANDLED;
+ }
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
+ nct6694_can_handle_bus_err(ndev, priv->event[can_idx].err);
+ handled = IRQ_HANDLED;
+ }
+
+ if (handled)
+ can_rx_offload_threaded_irq_finish(&priv->offload);
+
+ if (priv->event[can_idx].tx_evt & NCT6694_CAN_EVT_TX_FIFO_EMPTY)
+ nct6694_can_tx_irq(ndev);
+
+ priv->bec.rxerr = priv->event[can_idx].rec;
+ priv->bec.txerr = priv->event[can_idx].tec;
+
+ return handled;
+}
+
+static void nct6694_can_tx_work(struct work_struct *work)
+{
+ struct nct6694_can_priv *priv = container_of(work,
+ struct nct6694_can_priv,
+ tx_work);
+ struct nct6694_can_frame *frame = &priv->tx;
+ struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CAN_MOD,
+ .cmd = NCT6694_CAN_DELIVER,
+ .sel = NCT6694_CAN_DELIVER_SEL(1),
+ .len = cpu_to_le16(sizeof(*frame))
+ };
+ struct net_device *ndev = priv->ndev;
+ struct net_device_stats *stats = &ndev->stats;
+ struct sk_buff *skb = priv->can.echo_skb[0];
+ u32 txid;
+ int err;
+
+ memset(frame, 0, sizeof(*frame));
+
+ if (priv->can_idx == 0)
+ frame->tag = NCT6694_CAN_FRAME_TAG_CAN0;
+ else
+ frame->tag = NCT6694_CAN_FRAME_TAG_CAN1;
+
+ if (can_is_canfd_skb(skb)) {
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (cfd->flags & CANFD_BRS)
+ frame->flag |= NCT6694_CAN_FRAME_FLAG_BRS;
+
+ if (cfd->can_id & CAN_EFF_FLAG) {
+ txid = cfd->can_id & CAN_EFF_MASK;
+ frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
+ } else {
+ txid = cfd->can_id & CAN_SFF_MASK;
+ }
+ frame->flag |= NCT6694_CAN_FRAME_FLAG_FD;
+ frame->id = cpu_to_le32(txid);
+ frame->length = cfd->len;
+
+ memcpy(frame->data, cfd->data, cfd->len);
+ } 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_CAN_FRAME_FLAG_EFF;
+ } else {
+ txid = cf->can_id & CAN_SFF_MASK;
+ }
+
+ if (cf->can_id & CAN_RTR_FLAG)
+ frame->flag |= NCT6694_CAN_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) {
+ netdev_err(ndev, "%s: TX FIFO is full!\n", __func__);
+ can_free_echo_skb(ndev, 0, NULL);
+ stats->tx_dropped++;
+ stats->tx_errors++;
+ netif_wake_queue(ndev);
+ }
+}
+
+static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
+ struct net_device *ndev)
+{
+ struct nct6694_can_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_can_start(struct net_device *ndev)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_setting *setting;
+ struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CAN_MOD,
+ .cmd = NCT6694_CAN_SETTING,
+ .sel = priv->can_idx,
+ .len = cpu_to_le16(sizeof(*setting))
+ };
+ const struct can_bittiming *n_bt = &priv->can.bittiming;
+ const struct can_bittiming *d_bt = &priv->can.data_bittiming;
+ int ret;
+
+ setting = kzalloc(sizeof(*setting), GFP_KERNEL);
+ if (!setting)
+ return -ENOMEM;
+
+ setting->nbr = cpu_to_le32(n_bt->bitrate);
+ setting->dbr = cpu_to_le32(d_bt->bitrate);
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_MON);
+
+ if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
+ priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_NISO);
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+ setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_LBCK);
+
+ ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
+ if (ret)
+ goto exit;
+
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+exit:
+ kfree(setting);
+ return ret;
+}
+
+static int nct6694_can_stop(struct net_device *ndev)
+{
+ struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ free_irq(ndev->irq, ndev);
+ destroy_workqueue(priv->wq);
+ priv->wq = NULL;
+ priv->can.state = CAN_STATE_STOPPED;
+ can_rx_offload_disable(&priv->offload);
+ close_candev(ndev);
+
+ return 0;
+}
+
+static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+ switch (mode) {
+ case CAN_MODE_START:
+ nct6694_can_start(ndev);
+ netif_wake_queue(ndev);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int nct6694_can_open(struct net_device *ndev)
+{
+ struct nct6694_can_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_can_irq, IRQF_ONESHOT,
+ "nct6694_can", ndev);
+ if (ret) {
+ netdev_err(ndev, "Failed to request IRQ\n");
+ goto close_candev;
+ }
+
+ 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_can_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);
+close_candev:
+ can_rx_offload_disable(&priv->offload);
+ close_candev(ndev);
+ return ret;
+}
+
+static const struct net_device_ops nct6694_can_netdev_ops = {
+ .ndo_open = nct6694_can_open,
+ .ndo_stop = nct6694_can_stop,
+ .ndo_start_xmit = nct6694_can_start_xmit,
+ .ndo_change_mtu = can_change_mtu,
+};
+
+static const struct ethtool_ops nct6694_can_ethtool_ops = {
+ .get_ts_info = ethtool_op_get_ts_info,
+};
+
+static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
+{
+ struct nct6694_can_information *info;
+ struct nct6694_cmd_header cmd_hd = {
+ .mod = NCT6694_CAN_MOD,
+ .cmd = NCT6694_CAN_INFORMATION,
+ .sel = NCT6694_CAN_INFORMATION_SEL,
+ .len = cpu_to_le16(sizeof(*info))
+ };
+ int ret, can_clk;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ ret = nct6694_read_msg(priv->nct6694, &cmd_hd, info);
+ if (ret)
+ goto exit;
+
+ can_clk = le32_to_cpu(info->can_clk);
+
+exit:
+ kfree(info);
+ return can_clk;
+}
+
+static int nct6694_can_probe(struct platform_device *pdev)
+{
+ const struct mfd_cell *cell = mfd_get_cell(pdev);
+ struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+ struct nct6694_can_priv *priv;
+ struct net_device *ndev;
+ int ret, irq, can_clk;
+
+ irq = irq_create_mapping(nct6694->domain,
+ NCT6694_IRQ_CAN1 + cell->id);
+ if (!irq)
+ return irq;
+
+ ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1);
+ if (!ndev)
+ return -ENOMEM;
+
+ ndev->irq = irq;
+ ndev->flags |= IFF_ECHO;
+ ndev->dev_port = cell->id;
+ ndev->netdev_ops = &nct6694_can_netdev_ops;
+ ndev->ethtool_ops = &nct6694_can_ethtool_ops;
+
+ priv = netdev_priv(ndev);
+ priv->nct6694 = nct6694;
+ priv->ndev = ndev;
+
+ can_clk = nct6694_can_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_can_tx_work);
+
+ priv->can_idx = cell->id;
+ priv->can.state = CAN_STATE_STOPPED;
+ priv->can.clock.freq = can_clk;
+ priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
+ priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
+ priv->can.do_set_mode = nct6694_can_set_mode;
+ priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
+
+ priv->can.ctrlmode = CAN_CTRLMODE_FD;
+
+ priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+ CAN_CTRLMODE_LISTENONLY |
+ CAN_CTRLMODE_FD |
+ CAN_CTRLMODE_FD_NON_ISO |
+ CAN_CTRLMODE_BERR_REPORTING;
+
+ 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 del_rx_offload;
+
+ return 0;
+
+del_rx_offload:
+ can_rx_offload_del(&priv->offload);
+free_candev:
+ free_candev(ndev);
+ return ret;
+}
+
+static void nct6694_can_remove(struct platform_device *pdev)
+{
+ struct nct6694_can_priv *priv = platform_get_drvdata(pdev);
+
+ cancel_work_sync(&priv->tx_work);
+ unregister_candev(priv->ndev);
+ can_rx_offload_del(&priv->offload);
+ free_candev(priv->ndev);
+}
+
+static struct platform_driver nct6694_can_driver = {
+ .driver = {
+ .name = DRVNAME,
+ },
+ .probe = nct6694_can_probe,
+ .remove = nct6694_can_remove,
+};
+
+module_platform_driver(nct6694_can_driver);
+
+MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-can");
--
2.34.1