[PATCH v2 4/7] can: Add Nuvoton NCT6694 CAN support

Ming Yu
2024-11-21T06:41:17Z

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

Signed-off-by: Ming Yu <tmyu0@nuvoton.com>
---
MAINTAINERS | 1 +
drivers/net/can/Kconfig | 10 +
drivers/net/can/Makefile | 1 +
drivers/net/can/nct6694_canfd.c | 926 ++++++++++++++++++++++++++++++++
4 files changed, 938 insertions(+)
create mode 100644 drivers/net/can/nct6694_canfd.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a190f2b08fa3..eb5d46825e71 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16548,6 +16548,7 @@ S: Supported
F: drivers/gpio/gpio-nct6694.c
F: drivers/i2c/busses/i2c-nct6694.c
F: drivers/mfd/nct6694.c
+F: drivers/net/can/nct6694_canfd.c
F: include/linux/mfd/nct6694.h

NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index cf989bea9aa3..130e98ec28a5 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -200,6 +200,16 @@ config CAN_SUN4I
To compile this driver as a module, choose M here: the module will
be called sun4i_can.

+config CAN_NCT6694
+ tristate "Nuvoton NCT6694 Socket CANfd support"
+ depends on MFD_NCT6694
+ 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_TI_HECC
depends on ARM
tristate "TI High End CAN Controller"
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index a71db2cfe990..4a6b5b9d6c2b 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o
obj-$(CONFIG_CAN_KVASER_PCIEFD) += kvaser_pciefd.o
obj-$(CONFIG_CAN_MSCAN) += mscan/
obj-$(CONFIG_CAN_M_CAN) += m_can/
+obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_canfd/
obj-$(CONFIG_CAN_SJA1000) += sja1000/
obj-$(CONFIG_CAN_SUN4I) += sun4i_can.o
diff --git a/drivers/net/can/nct6694_canfd.c b/drivers/net/can/nct6694_canfd.c
new file mode 100644
index 000000000000..d488414981ec
--- /dev/null
+++ b/drivers/net/can/nct6694_canfd.c
@@ -0,0 +1,926 @@
+// 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/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-can"
+
+/* Host interface */
+#define NCT6694_CAN_MOD 0x05
+
+/* Message Channel*/
+/* Command 00h */
+#define NCT6694_CAN_CMD0_LEN 0x18
+#define NCT6694_CAN_CMD0_OFFSET(idx) (idx ? 0x0100 : 0x0000)
+#define NCT6694_CAN_CTRL1_MON BIT(0)
+#define NCT6694_CAN_CTRL1_NISO BIT(1)
+#define NCT6694_CAN_CTRL1_LBCK BIT(2)
+
+/* Command 01h */
+#define NCT6694_CAN_CMD1_LEN 0x08
+#define NCT6694_CAN_CMD1_OFFSET 0x0001
+
+/* Command 02h */
+#define NCT6694_CAN_CMD2_LEN 0x10
+#define NCT6694_CAN_CMD2_OFFSET(idx, mask) \
+ ({ typeof(mask) mask_ = (mask); \
+ idx ? ((0x80 | (mask_ & 0xFF)) << 8 | 0x02) : \
+ ((0x00 | (mask_ & 0xFF)) << 8 | 0x02); })
+
+#define NCT6694_CAN_EVENT_ERR BIT(0)
+#define NCT6694_CAN_EVENT_STATUS BIT(1)
+#define NCT6694_CAN_EVENT_TX_EVT BIT(2)
+#define NCT6694_CAN_EVENT_RX_EVT BIT(3)
+#define NCT6694_CAN_EVENT_REC BIT(4)
+#define NCT6694_CAN_EVENT_TEC BIT(5)
+#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_HALF_FULL BIT(6) /* Read-clear */
+#define NCT6694_CAN_EVT_RX_DATA_IN BIT(7)
+
+/* Command 10h */
+#define NCT6694_CAN_CMD10_LEN 0x90
+#define NCT6694_CAN_CMD10_OFFSET(buf_cnt) \
+ (((buf_cnt) & 0xFF) << 8 | 0x10)
+#define NCT6694_CAN_TAG_CAN0 0xC0
+#define NCT6694_CAN_TAG_CAN1 0xC1
+#define NCT6694_CAN_FLAG_EFF BIT(0)
+#define NCT6694_CAN_FLAG_RTR BIT(1)
+#define NCT6694_CAN_FLAG_FD BIT(2)
+#define NCT6694_CAN_FLAG_BRS BIT(3)
+#define NCT6694_CAN_FLAG_ERR BIT(4)
+
+/* Command 11h */
+#define NCT6694_CAN_CMD11_LEN 0x90
+#define NCT6694_CAN_CMD11_OFFSET(idx, buf_cnt) \
+ ({ typeof(buf_cnt) buf_cnt_ = (buf_cnt); \
+ idx ? ((0x80 | (buf_cnt_ & 0xFF)) << 8 | 0x11) : \
+ ((0x00 | (buf_cnt_ & 0xFF)) << 8 | 0x11); })
+
+#define NCT6694_CAN_RX_QUOTA 64
+
+enum nct6694_event_err {
+ NCT6694_CAN_EVT_NO_ERROR,
+ NCT6694_CAN_EVT_CRC_ERROR,
+ NCT6694_CAN_EVT_STUFF_ERROR,
+ NCT6694_CAN_EVT_ACK_ERROR,
+ NCT6694_CAN_EVT_FORM_ERROR,
+ NCT6694_CAN_EVT_BIT_ERROR,
+ NCT6694_CAN_EVT_TIMEOUT_ERROR,
+ NCT6694_CAN_EVT_UNKNOWN_ERROR,
+};
+
+enum nct6694_event_status {
+ NCT6694_CAN_EVT_ERROR_ACTIVE,
+ NCT6694_CAN_EVT_ERROR_PASSIVE,
+ NCT6694_CAN_EVT_BUS_OFF,
+ NCT6694_CAN_EVT_WARNING,
+};
+
+struct __packed nct6694_can_cmd0 {
+ u32 nbr;
+ u32 dbr;
+ u32 active:8;
+ u32 reserved:24;
+ u16 ctrl1;
+ u16 ctrl2;
+ u32 nbtp;
+ u32 dbtp;
+};
+
+struct __packed nct6694_can_cmd1 {
+ u8 tx_fifo_cnt;
+ u8 rx_fifo_cnt;
+ u16 reserved;
+ __le32 can_clk;
+};
+
+struct __packed nct6694_can_cmd2 {
+ u8 err1;
+ u8 status1;
+ u8 tx_evt1;
+ u8 rx_evt1;
+ u8 rec1;
+ u8 tec1;
+ u8 reserved1[2];
+ u8 err2;
+ u8 status2;
+ u8 tx_evt2;
+ u8 rx_evt2;
+ u8 rec2;
+ u8 tec2;
+ u8 reserved2[2];
+};
+
+struct __packed nct6694_can_cmd10_11 {
+ u8 tag;
+ u8 flag;
+ u8 reserved;
+ u8 dlc;
+ __le32 id;
+ u8 data[64];
+ u8 msg_buf[72];
+};
+
+struct nct6694_canfd_priv {
+ struct can_priv can; /* must be the first member */
+ struct net_device *ndev;
+ struct nct6694 *nct6694;
+ struct mutex lock;
+ struct sk_buff *tx_skb;
+ struct workqueue_struct *wq;
+ struct work_struct tx_work;
+ unsigned char *tx_buf;
+ unsigned char *rx_buf;
+ unsigned char can_idx;
+ bool tx_busy;
+};
+
+static const struct can_bittiming_const nct6694_canfd_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_canfd_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_canfd_clean(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+
+ if (priv->tx_skb || priv->tx_busy)
+ ndev->stats.tx_errors++;
+ dev_kfree_skb(priv->tx_skb);
+ if (priv->tx_busy)
+ can_free_echo_skb(priv->ndev, 0, NULL);
+ priv->tx_skb = NULL;
+ priv->tx_busy = false;
+}
+
+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);
+ struct nct6694_can_cmd2 *buf = (struct nct6694_can_cmd2 *)priv->rx_buf;
+ u8 mask = NCT6694_CAN_EVENT_REC | NCT6694_CAN_EVENT_TEC;
+ int ret;
+
+ guard(mutex)(&priv->lock);
+
+ ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD2_OFFSET(priv->can_idx, mask),
+ NCT6694_CAN_CMD2_LEN,
+ buf);
+ if (ret < 0)
+ return ret;
+
+ bec->rxerr = priv->can_idx ? buf->rec2 : buf->rec1;
+ bec->txerr = priv->can_idx ? buf->tec2 : buf->tec1;
+
+ return 0;
+}
+
+static int nuv_canfd_handle_lost_msg(struct net_device *ndev)
+{
+ struct net_device_stats *stats = &ndev->stats;
+ struct sk_buff *skb;
+ struct can_frame *frame;
+
+ netdev_err(ndev, "RX FIFO overflow, message(s) lost.\n");
+
+ stats->rx_errors++;
+ stats->rx_over_errors++;
+
+ skb = alloc_can_err_skb(ndev, &frame);
+ if (unlikely(!skb))
+ return 0;
+
+ frame->can_id |= CAN_ERR_CRTL;
+ frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+ netif_receive_skb(skb);
+
+ return 1;
+}
+
+static void nuv_canfd_read_fifo(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_cmd10_11 *buf = (struct nct6694_can_cmd10_11 *)priv->rx_buf;
+ struct net_device_stats *stats = &ndev->stats;
+ struct canfd_frame *cf;
+ struct sk_buff *skb;
+ int can_idx = priv->can_idx;
+ u32 id;
+ int ret;
+ u8 fd_format = 0;
+ int i;
+
+ guard(mutex)(&priv->lock);
+
+ ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD11_OFFSET(can_idx, 1),
+ NCT6694_CAN_CMD11_LEN, buf);
+ if (ret < 0)
+ return;
+
+ /* Check type of frame and create skb */
+ fd_format = buf->flag & NCT6694_CAN_FLAG_FD;
+ if (fd_format)
+ skb = alloc_canfd_skb(ndev, &cf);
+ else
+ skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
+
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cf->len = buf->dlc;
+
+ /* Get ID and set flag by its type(Standard ID format or Ext ID format) */
+ id = le32_to_cpu(buf->id);
+ if (buf->flag & NCT6694_CAN_FLAG_EFF) {
+ /*
+ * In case the Extended ID frame is received, the standard
+ * and extended part of the ID are swapped in the register,
+ * so swap them back to obtain the correct ID.
+ */
+ id |= CAN_EFF_FLAG;
+ }
+
+ cf->can_id = id;
+
+ /* Set ESI flag */
+ if (buf->flag & NCT6694_CAN_FLAG_ERR) {
+ cf->flags |= CANFD_ESI;
+ netdev_dbg(ndev, "ESI Error\n");
+ }
+
+ /* Set RTR and BRS */
+ if (!fd_format && (buf->flag & NCT6694_CAN_FLAG_RTR)) {
+ cf->can_id |= CAN_RTR_FLAG;
+ } else {
+ if (buf->flag & NCT6694_CAN_FLAG_BRS)
+ cf->flags |= CANFD_BRS;
+
+ for (i = 0; i < cf->len; i++)
+ cf->data[i] = buf->data[i];
+ }
+
+ /* Remove the packet from FIFO */
+ stats->rx_packets++;
+ stats->rx_bytes += cf->len;
+ netif_receive_skb(skb);
+}
+
+static int nct6694_canfd_do_rx_poll(struct net_device *ndev, int quota)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_cmd2 *buf = (struct nct6694_can_cmd2 *)priv->rx_buf;
+ int can_idx = priv->can_idx;
+ u32 pkts = 0;
+ u8 mask_rx = NCT6694_CAN_EVENT_RX_EVT;
+ u8 rx_evt;
+
+ for (;;) {
+ scoped_guard(mutex, &priv->lock) {
+ nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD2_OFFSET(can_idx, mask_rx),
+ NCT6694_CAN_CMD2_LEN, buf);
+
+ rx_evt = can_idx ? buf->rx_evt2 : buf->rx_evt1;
+ }
+
+ if (rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST)
+ nuv_canfd_handle_lost_msg(ndev);
+
+ /* No data */
+ if ((rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) == 0)
+ break;
+
+ if (quota <= 0)
+ break;
+
+ nuv_canfd_read_fifo(ndev);
+ quota--;
+ pkts++;
+ }
+
+ return pkts;
+}
+
+static int nct6694_canfd_handle_lec_err(struct net_device *ndev, u8 bus_err)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ if (bus_err == NCT6694_CAN_EVT_NO_ERROR)
+ return 0;
+
+ priv->can.can_stats.bus_error++;
+ stats->rx_errors++;
+
+ /* Propagate the error condition to the CAN stack. */
+ skb = alloc_can_err_skb(ndev, &cf);
+
+ if (unlikely(!skb))
+ return 0;
+
+ /* Read the error counter register and check for new errors. */
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ switch (bus_err) {
+ case NCT6694_CAN_EVT_CRC_ERROR:
+ cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+ break;
+
+ case NCT6694_CAN_EVT_STUFF_ERROR:
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+
+ case NCT6694_CAN_EVT_ACK_ERROR:
+ cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+ break;
+
+ case NCT6694_CAN_EVT_FORM_ERROR:
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+
+ case NCT6694_CAN_EVT_BIT_ERROR:
+ cf->data[2] |= CAN_ERR_PROT_BIT |
+ CAN_ERR_PROT_BIT0 |
+ CAN_ERR_PROT_BIT1;
+ break;
+
+ case NCT6694_CAN_EVT_TIMEOUT_ERROR:
+ cf->data[2] |= CAN_ERR_PROT_UNSPEC;
+ break;
+
+ case NCT6694_CAN_EVT_UNKNOWN_ERROR:
+ cf->data[2] |= CAN_ERR_PROT_UNSPEC;
+ /*
+ * It means 'unspecified'(the value is '0').
+ * But it is not sure if it's ok to send an error package
+ * without specific error bit.
+ */
+ break;
+
+ default:
+ break;
+ }
+
+ /* Reset the error counter, ack the IRQ and re-enable the counter. */
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
+
+ return 1;
+}
+
+static int nct6694_canfd_handle_state_change(struct net_device *ndev,
+ enum can_state new_state)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ struct can_berr_counter bec;
+
+ switch (new_state) {
+ case CAN_STATE_ERROR_ACTIVE:
+ /* error active state */
+ priv->can.can_stats.error_warning++;
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ break;
+ case CAN_STATE_ERROR_WARNING:
+ /* error warning state */
+ priv->can.can_stats.error_warning++;
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ break;
+ case CAN_STATE_ERROR_PASSIVE:
+ /* error passive state */
+ priv->can.can_stats.error_passive++;
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ break;
+ case CAN_STATE_BUS_OFF:
+ /* bus-off state */
+ priv->can.state = CAN_STATE_BUS_OFF;
+ priv->can.can_stats.bus_off++;
+ can_bus_off(ndev);
+ break;
+ default:
+ break;
+ }
+
+ /* propagate the error condition to the CAN stack */
+ skb = alloc_can_err_skb(ndev, &cf);
+ if (unlikely(!skb))
+ return 0;
+
+ nct6694_canfd_get_berr_counter(ndev, &bec);
+
+ switch (new_state) {
+ case CAN_STATE_ERROR_WARNING:
+ /* error warning state */
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = (bec.txerr > bec.rxerr) ? CAN_ERR_CRTL_TX_WARNING :
+ CAN_ERR_CRTL_RX_WARNING;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ break;
+ case CAN_STATE_ERROR_PASSIVE:
+ /* error passive state */
+ 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:
+ /* bus-off state */
+ cf->can_id |= CAN_ERR_BUSOFF;
+ break;
+ default:
+ break;
+ }
+
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
+
+ return 1;
+}
+
+static int nct6694_canfd_handle_state_errors(struct net_device *ndev,
+ unsigned char can_status)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ int work_done = 0;
+
+ if (can_status == NCT6694_CAN_EVT_ERROR_ACTIVE &&
+ priv->can.state != CAN_STATE_ERROR_ACTIVE) {
+ netdev_dbg(ndev, "Error, entered active state\n");
+ work_done += nct6694_canfd_handle_state_change(ndev,
+ CAN_STATE_ERROR_ACTIVE);
+ }
+
+ if (can_status == NCT6694_CAN_EVT_WARNING &&
+ priv->can.state != CAN_STATE_ERROR_WARNING) {
+ netdev_dbg(ndev, "Error, entered warning state\n");
+ work_done += nct6694_canfd_handle_state_change(ndev,
+ CAN_STATE_ERROR_WARNING);
+ }
+
+ if (can_status == NCT6694_CAN_EVT_ERROR_PASSIVE &&
+ priv->can.state != CAN_STATE_ERROR_PASSIVE) {
+ netdev_dbg(ndev, "Error, entered passive state\n");
+ work_done += nct6694_canfd_handle_state_change(ndev,
+ CAN_STATE_ERROR_PASSIVE);
+ }
+
+ if (can_status == NCT6694_CAN_EVT_BUS_OFF &&
+ priv->can.state != CAN_STATE_BUS_OFF) {
+ netdev_dbg(ndev, "Error, entered bus-off state\n");
+ work_done += nct6694_canfd_handle_state_change(ndev,
+ CAN_STATE_BUS_OFF);
+ }
+
+ return work_done;
+}
+
+static int nct6694_canfd_poll(struct net_device *ndev, int quota)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_cmd2 *buf = (struct nct6694_can_cmd2 *)priv->rx_buf;
+ int can_idx = priv->can_idx;
+ int work_done = 0, ret;
+ u8 evt_mask = NCT6694_CAN_EVENT_ERR | NCT6694_CAN_EVENT_STATUS;
+ u8 bus_err, can_status;
+
+ scoped_guard(mutex, &priv->lock) {
+ ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD2_OFFSET(can_idx, evt_mask),
+ NCT6694_CAN_CMD2_LEN, buf);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ if (can_idx) {
+ bus_err = buf->err2;
+ can_status = buf->status2;
+ } else {
+ bus_err = buf->err1;
+ can_status = buf->status1;
+ }
+ }
+
+ /* Handle bus state changes */
+ work_done += nct6694_canfd_handle_state_errors(ndev, can_status);
+
+ /* Handle lec errors on the bus */
+ if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+ work_done += nct6694_canfd_handle_lec_err(ndev, bus_err);
+
+ /* Handle RX events */
+ work_done += nct6694_canfd_do_rx_poll(ndev, quota - work_done);
+ return work_done;
+}
+
+static void nct6694_canfd_tx_irq(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+
+ guard(mutex)(&priv->lock);
+ stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
+ stats->tx_packets++;
+ priv->tx_busy = false;
+ 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_can_cmd2 *buf = (struct nct6694_can_cmd2 *)priv->rx_buf;
+ int can_idx = priv->can_idx;
+ int ret;
+ u8 mask_sts = NCT6694_CAN_EVENT_TX_EVT;
+ u8 tx_evt;
+
+ scoped_guard(mutex, &priv->lock) {
+ ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD2_OFFSET(can_idx, mask_sts),
+ NCT6694_CAN_CMD2_LEN, buf);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ tx_evt = can_idx ? buf->tx_evt2 : buf->tx_evt1;
+ }
+
+ if (tx_evt) {
+ nct6694_canfd_tx_irq(ndev);
+ } else {
+ ret = nct6694_canfd_poll(ndev, NCT6694_CAN_RX_QUOTA);
+ if (!ret)
+ return IRQ_NONE;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int nct6694_canfd_start(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_cmd0 *buf = (struct nct6694_can_cmd0 *)priv->tx_buf;
+ const struct can_bittiming *n_bt = &priv->can.bittiming;
+ const struct can_bittiming *d_bt = &priv->can.data_bittiming;
+ int ret;
+
+ guard(mutex)(&priv->lock);
+
+ memset(priv->tx_buf, 0, NCT6694_CAN_CMD0_LEN);
+ buf->nbr = n_bt->bitrate;
+ buf->dbr = d_bt->bitrate;
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+ buf->ctrl1 |= NCT6694_CAN_CTRL1_MON;
+
+ if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
+ priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
+ buf->ctrl1 |= NCT6694_CAN_CTRL1_NISO;
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+ buf->ctrl1 |= NCT6694_CAN_CTRL1_LBCK;
+
+ ret = nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD0_OFFSET(priv->can_idx),
+ NCT6694_CAN_CMD0_LEN, buf);
+ if (ret < 0)
+ return ret;
+
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ return 0;
+}
+
+static int nct6694_canfd_stop(struct net_device *ndev)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ free_irq(ndev->irq, ndev);
+ destroy_workqueue(priv->wq);
+ priv->wq = NULL;
+ nct6694_canfd_clean(ndev);
+ priv->can.state = CAN_STATE_STOPPED;
+ close_candev(ndev);
+
+ return 0;
+}
+
+static int nct6694_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+ switch (mode) {
+ case CAN_MODE_START:
+ nct6694_canfd_clean(ndev);
+ nct6694_canfd_start(ndev);
+ netif_wake_queue(ndev);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+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;
+
+ ret = request_threaded_irq(ndev->irq, NULL,
+ nct6694_canfd_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;
+ }
+
+ priv->tx_skb = NULL;
+ priv->tx_busy = false;
+
+ 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);
+close_candev:
+ close_candev(ndev);
+ return ret;
+}
+
+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 (priv->tx_skb || priv->tx_busy) {
+ netdev_err(ndev, "hard_xmit called while tx busy\n");
+ return NETDEV_TX_BUSY;
+ }
+
+ if (can_dev_dropped_skb(ndev, skb))
+ return NETDEV_TX_OK;
+
+ netif_stop_queue(ndev);
+ priv->tx_skb = skb;
+ queue_work(priv->wq, &priv->tx_work);
+
+ return NETDEV_TX_OK;
+}
+
+static void nct6694_canfd_tx(struct net_device *ndev, struct canfd_frame *cf)
+{
+ struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+ struct nct6694_can_cmd10_11 *buf = (struct nct6694_can_cmd10_11 *)priv->tx_buf;
+ u32 txid = 0;
+ int i;
+
+ memset(buf, 0, NCT6694_CAN_CMD10_LEN);
+
+ if (priv->can_idx == 0)
+ buf->tag = NCT6694_CAN_TAG_CAN0;
+ else
+ buf->tag = NCT6694_CAN_TAG_CAN1;
+
+ if (cf->can_id & CAN_EFF_FLAG) {
+ txid = cf->can_id & CAN_EFF_MASK;
+ /*
+ * In case the Extended ID frame is transmitted, the
+ * standard and extended part of the ID are swapped
+ * in the register, so swap them back to send the
+ * correct ID.
+ */
+ buf->flag |= NCT6694_CAN_FLAG_EFF;
+ } else {
+ txid = cf->can_id & CAN_SFF_MASK;
+ }
+
+ buf->id = cpu_to_le32(txid);
+ buf->dlc = cf->len;
+
+ if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
+ can_is_canfd_skb(priv->tx_skb)) {
+ buf->flag |= NCT6694_CAN_FLAG_FD;
+ if (cf->flags & CANFD_BRS)
+ buf->flag |= NCT6694_CAN_FLAG_BRS;
+ }
+
+ if (cf->can_id & CAN_RTR_FLAG)
+ buf->flag |= NCT6694_CAN_FLAG_RTR;
+
+ /* set data to buf */
+ for (i = 0; i < cf->len; i++)
+ buf->data[i] = cf->data[i];
+
+ nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD10_OFFSET(1),
+ NCT6694_CAN_CMD10_LEN,
+ buf);
+}
+
+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 net_device *ndev = priv->ndev;
+ struct canfd_frame *cf;
+
+ guard(mutex)(&priv->lock);
+
+ if (priv->tx_skb) {
+ if (priv->can.state == CAN_STATE_BUS_OFF) {
+ nct6694_canfd_clean(ndev);
+ } else {
+ cf = (struct canfd_frame *)priv->tx_skb->data;
+ nct6694_canfd_tx(ndev, cf);
+ priv->tx_busy = true;
+ can_put_echo_skb(priv->tx_skb, ndev, 0, 0);
+ priv->tx_skb = NULL;
+ }
+ }
+}
+
+static const struct net_device_ops nct6694_canfd_netdev_ops = {
+ .ndo_open = nct6694_canfd_open,
+ .ndo_stop = nct6694_canfd_stop,
+ .ndo_start_xmit = nct6694_canfd_start_xmit,
+ .ndo_change_mtu = can_change_mtu,
+};
+
+static int nct6694_canfd_get_clock(struct nct6694_canfd_priv *priv)
+{
+ struct nct6694_can_cmd1 *buf = (struct nct6694_can_cmd1 *)priv->rx_buf;
+ int ret;
+
+ ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
+ NCT6694_CAN_CMD1_OFFSET,
+ NCT6694_CAN_CMD1_LEN,
+ buf);
+ if (ret)
+ return ret;
+
+ return le32_to_cpu(buf->can_clk);
+}
+
+static int nct6694_canfd_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_canfd_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 -EINVAL;
+
+ ndev = alloc_candev(sizeof(struct nct6694_canfd_priv), 1);
+ if (!ndev)
+ return -ENOMEM;
+
+ ndev->irq = irq;
+ ndev->flags |= IFF_ECHO;
+ ndev->netdev_ops = &nct6694_canfd_netdev_ops;
+
+ priv = netdev_priv(ndev);
+ priv->nct6694 = nct6694;
+ priv->ndev = ndev;
+
+ priv->tx_buf = devm_kcalloc(&pdev->dev, NCT6694_MAX_PACKET_SZ,
+ sizeof(unsigned char), GFP_KERNEL);
+ if (!priv->tx_buf) {
+ ret = -ENOMEM;
+ goto free_candev;
+ }
+
+ priv->rx_buf = devm_kcalloc(&pdev->dev, NCT6694_MAX_PACKET_SZ,
+ sizeof(unsigned char), GFP_KERNEL);
+ if (!priv->rx_buf) {
+ ret = -ENOMEM;
+ goto free_candev;
+ }
+
+ can_clk = nct6694_canfd_get_clock(priv);
+ if (can_clk < 0) {
+ ret = -EIO;
+ goto free_candev;
+ }
+
+ mutex_init(&priv->lock);
+ INIT_WORK(&priv->tx_work, nct6694_canfd_tx_work);
+
+ priv->can_idx = cell->id;
+ priv->can.state = CAN_STATE_STOPPED;
+ priv->can.clock.freq = can_clk;
+ priv->can.bittiming_const = &nct6694_canfd_bittiming_nominal_const;
+ priv->can.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 = 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;
+
+ platform_set_drvdata(pdev, priv);
+ SET_NETDEV_DEV(priv->ndev, &pdev->dev);
+
+ ret = register_candev(priv->ndev);
+ if (ret)
+ goto free_candev;
+
+ return 0;
+
+free_candev:
+ free_candev(ndev);
+ return dev_err_probe(&pdev->dev, ret, "Probe failed\n");
+}
+
+static void nct6694_canfd_remove(struct platform_device *pdev)
+{
+ struct nct6694_canfd_priv *priv = platform_get_drvdata(pdev);
+
+ cancel_work_sync(&priv->tx_work);
+ unregister_candev(priv->ndev);
+ free_candev(priv->ndev);
+}
+
+static struct platform_driver nct6694_canfd_driver = {
+ .driver = {
+ .name = DRVNAME,
+ },
+ .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");
--
2.34.1