--- /dev/null
+/*
+ * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
+ *
+ * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/usb.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+
+MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
+MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
+MODULE_LICENSE("GPL v2");
+
+/* Control-Values for CPC_Control() Command Subject Selection */
+#define CONTR_CAN_MESSAGE 0x04
+#define CONTR_CAN_STATE 0x0C
+#define CONTR_BUS_ERROR 0x1C
+
+/* Control Command Actions */
+#define CONTR_CONT_OFF 0
+#define CONTR_CONT_ON 1
+#define CONTR_ONCE 2
+
+/* Messages from CPC to PC */
+#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
+#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
+#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
+#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
+#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
+#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
+#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
+#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
+#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
+#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
+#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
+
+/* Messages from the PC to the CPC interface */
+#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
+#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
+#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
+#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
+#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
+#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
+#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
+#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
+
+#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
+#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
+#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
+
+#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
+
+#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
+
+/* Overrun types */
+#define CPC_OVR_EVENT_CAN 0x01
+#define CPC_OVR_EVENT_CANSTATE 0x02
+#define CPC_OVR_EVENT_BUSERROR 0x04
+
+/*
+ * If the CAN controller lost a message we indicate it with the highest bit
+ * set in the count field.
+ */
+#define CPC_OVR_HW 0x80
+
+/* Size of the "struct ems_cpc_msg" without the union */
+#define CPC_MSG_HEADER_LEN 11
+#define CPC_CAN_MSG_MIN_SIZE 5
+
+/* Define these values to match your devices */
+#define USB_CPCUSB_VENDOR_ID 0x12D6
+
+#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
+
+/* Mode register NXP LPC2119/SJA1000 CAN Controller */
+#define SJA1000_MOD_NORMAL 0x00
+#define SJA1000_MOD_RM 0x01
+
+/* ECC register NXP LPC2119/SJA1000 CAN Controller */
+#define SJA1000_ECC_SEG 0x1F
+#define SJA1000_ECC_DIR 0x20
+#define SJA1000_ECC_ERR 0x06
+#define SJA1000_ECC_BIT 0x00
+#define SJA1000_ECC_FORM 0x40
+#define SJA1000_ECC_STUFF 0x80
+#define SJA1000_ECC_MASK 0xc0
+
+/* Status register content */
+#define SJA1000_SR_BS 0x80
+#define SJA1000_SR_ES 0x40
+
+#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
+
+/*
+ * The device actually uses a 16MHz clock to generate the CAN clock
+ * but it expects SJA1000 bit settings based on 8MHz (is internally
+ * converted).
+ */
+#define EMS_USB_ARM7_CLOCK 8000000
+
+/*
+ * CAN-Message representation in a CPC_MSG. Message object type is
+ * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
+ * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
+ */
+struct cpc_can_msg {
+ __le32 id;
+ u8 length;
+ u8 msg[8];
+};
+
+/* Representation of the CAN parameters for the SJA1000 controller */
+struct cpc_sja1000_params {
+ u8 mode;
+ u8 acc_code0;
+ u8 acc_code1;
+ u8 acc_code2;
+ u8 acc_code3;
+ u8 acc_mask0;
+ u8 acc_mask1;
+ u8 acc_mask2;
+ u8 acc_mask3;
+ u8 btr0;
+ u8 btr1;
+ u8 outp_contr;
+};
+
+/* CAN params message representation */
+struct cpc_can_params {
+ u8 cc_type;
+
+ /* Will support M16C CAN controller in the future */
+ union {
+ struct cpc_sja1000_params sja1000;
+ } cc_params;
+};
+
+/* Structure for confirmed message handling */
+struct cpc_confirm {
+ u8 error; /* error code */
+};
+
+/* Structure for overrun conditions */
+struct cpc_overrun {
+ u8 event;
+ u8 count;
+};
+
+/* SJA1000 CAN errors (compatible to NXP LPC2119) */
+struct cpc_sja1000_can_error {
+ u8 ecc;
+ u8 rxerr;
+ u8 txerr;
+};
+
+/* structure for CAN error conditions */
+struct cpc_can_error {
+ u8 ecode;
+
+ struct {
+ u8 cc_type;
+
+ /* Other controllers may also provide error code capture regs */
+ union {
+ struct cpc_sja1000_can_error sja1000;
+ } regs;
+ } cc;
+};
+
+/*
+ * Structure containing RX/TX error counter. This structure is used to request
+ * the values of the CAN controllers TX and RX error counter.
+ */
+struct cpc_can_err_counter {
+ u8 rx;
+ u8 tx;
+};
+
+/* Main message type used between library and application */
+struct __packed ems_cpc_msg {
+ u8 type; /* type of message */
+ u8 length; /* length of data within union 'msg' */
+ u8 msgid; /* confirmation handle */
+ __le32 ts_sec; /* timestamp in seconds */
+ __le32 ts_nsec; /* timestamp in nano seconds */
+
+ union {
+ u8 generic[64];
+ struct cpc_can_msg can_msg;
+ struct cpc_can_params can_params;
+ struct cpc_confirm confirmation;
+ struct cpc_overrun overrun;
+ struct cpc_can_error error;
+ struct cpc_can_err_counter err_counter;
+ u8 can_state;
+ } msg;
+};
+
+/*
+ * Table of devices that work with this driver
+ * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
+ */
+static struct usb_device_id ems_usb_table[] = {
+ {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
+ {} /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, ems_usb_table);
+
+#define RX_BUFFER_SIZE 64
+#define CPC_HEADER_SIZE 4
+#define INTR_IN_BUFFER_SIZE 4
+
+#define MAX_RX_URBS 10
+#define MAX_TX_URBS 10
+
+struct ems_usb;
+
+struct ems_tx_urb_context {
+ struct ems_usb *dev;
+
+ u32 echo_index;
+ u8 dlc;
+};
+
+struct ems_usb {
+ struct can_priv can; /* must be the first member */
+
+ struct sk_buff *echo_skb[MAX_TX_URBS];
+
+ struct usb_device *udev;
+ struct net_device *netdev;
+
+ atomic_t active_tx_urbs;
+ struct usb_anchor tx_submitted;
+ struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
+
+ struct usb_anchor rx_submitted;
+
+ struct urb *intr_urb;
+
+ u8 *tx_msg_buffer;
+
+ u8 *intr_in_buffer;
+ unsigned int free_slots; /* remember number of available slots */
+
+ struct ems_cpc_msg active_params; /* active controller parameters */
+};
+
+static void ems_usb_read_interrupt_callback(struct urb *urb)
+{
+ struct ems_usb *dev = urb->context;
+ struct net_device *netdev = dev->netdev;
+ int err;
+
+ if (!netif_device_present(netdev))
+ return;
+
+ switch (urb->status) {
+ case 0:
+ dev->free_slots = dev->intr_in_buffer[1];
+ break;
+
+ case -ECONNRESET: /* unlink */
+ case -ENOENT:
+ case -ESHUTDOWN:
+ return;
+
+ default:
+ netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
+ break;
+ }
+
+ err = usb_submit_urb(urb, GFP_ATOMIC);
+
+ if (err == -ENODEV)
+ netif_device_detach(netdev);
+ else if (err)
+ netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
+}
+
+static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
+{
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ int i;
+ struct net_device_stats *stats = &dev->netdev->stats;
+
+ skb = alloc_can_skb(dev->netdev, &cf);
+ if (skb == NULL)
+ return;
+
+ cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
+ cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
+
+ if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
+ msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
+ cf->can_id |= CAN_EFF_FLAG;
+
+ if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
+ msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
+ cf->can_id |= CAN_RTR_FLAG;
+ } else {
+ for (i = 0; i < cf->can_dlc; i++)
+ cf->data[i] = msg->msg.can_msg.msg[i];
+ }
+
+ netif_rx(skb);
+
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+}
+
+static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
+{
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ struct net_device_stats *stats = &dev->netdev->stats;
+
+ skb = alloc_can_err_skb(dev->netdev, &cf);
+ if (skb == NULL)
+ return;
+
+ if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
+ u8 state = msg->msg.can_state;
+
+ if (state & SJA1000_SR_BS) {
+ dev->can.state = CAN_STATE_BUS_OFF;
+ cf->can_id |= CAN_ERR_BUSOFF;
+
+ dev->can.can_stats.bus_off++;
+ can_bus_off(dev->netdev);
+ } else if (state & SJA1000_SR_ES) {
+ dev->can.state = CAN_STATE_ERROR_WARNING;
+ dev->can.can_stats.error_warning++;
+ } else {
+ dev->can.state = CAN_STATE_ERROR_ACTIVE;
+ dev->can.can_stats.error_passive++;
+ }
+ } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
+ u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
+ u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
+ u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
+
+ /* bus error interrupt */
+ dev->can.can_stats.bus_error++;
+ stats->rx_errors++;
+
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ switch (ecc & SJA1000_ECC_MASK) {
+ case SJA1000_ECC_BIT:
+ cf->data[2] |= CAN_ERR_PROT_BIT;
+ break;
+ case SJA1000_ECC_FORM:
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+ case SJA1000_ECC_STUFF:
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+ default:
+ cf->data[2] |= CAN_ERR_PROT_UNSPEC;
+ cf->data[3] = ecc & SJA1000_ECC_SEG;
+ break;
+ }
+
+ /* Error occurred during transmission? */
+ if ((ecc & SJA1000_ECC_DIR) == 0)
+ cf->data[2] |= CAN_ERR_PROT_TX;
+
+ if (dev->can.state == CAN_STATE_ERROR_WARNING ||
+ dev->can.state == CAN_STATE_ERROR_PASSIVE) {
+ cf->data[1] = (txerr > rxerr) ?
+ CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
+ }
+ } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+ stats->rx_over_errors++;
+ stats->rx_errors++;
+ }
+
+ netif_rx(skb);
+
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+}
+
+/*
+ * callback for bulk IN urb
+ */
+static void ems_usb_read_bulk_callback(struct urb *urb)
+{
+ struct ems_usb *dev = urb->context;
+ struct net_device *netdev;
+ int retval;
+
+ netdev = dev->netdev;
+
+ if (!netif_device_present(netdev))
+ return;
+
+ switch (urb->status) {
+ case 0: /* success */
+ break;
+
+ case -ENOENT:
+ return;
+
+ default:
+ netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
+ goto resubmit_urb;
+ }
+
+ if (urb->actual_length > CPC_HEADER_SIZE) {
+ struct ems_cpc_msg *msg;
+ u8 *ibuf = urb->transfer_buffer;
+ u8 msg_count, start;
+
+ msg_count = ibuf[0] & ~0x80;
+
+ start = CPC_HEADER_SIZE;
+
+ while (msg_count) {
+ msg = (struct ems_cpc_msg *)&ibuf[start];
+
+ switch (msg->type) {
+ case CPC_MSG_TYPE_CAN_STATE:
+ /* Process CAN state changes */
+ ems_usb_rx_err(dev, msg);
+ break;
+
+ case CPC_MSG_TYPE_CAN_FRAME:
+ case CPC_MSG_TYPE_EXT_CAN_FRAME:
+ case CPC_MSG_TYPE_RTR_FRAME:
+ case CPC_MSG_TYPE_EXT_RTR_FRAME:
+ ems_usb_rx_can_msg(dev, msg);
+ break;
+
+ case CPC_MSG_TYPE_CAN_FRAME_ERROR:
+ /* Process errorframe */
+ ems_usb_rx_err(dev, msg);
+ break;
+
+ case CPC_MSG_TYPE_OVERRUN:
+ /* Message lost while receiving */
+ ems_usb_rx_err(dev, msg);
+ break;
+ }
+
+ start += CPC_MSG_HEADER_LEN + msg->length;
+ msg_count--;
+
+ if (start > urb->transfer_buffer_length) {
+ netdev_err(netdev, "format error\n");
+ break;
+ }
+ }
+ }
+
+resubmit_urb:
+ usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
+ urb->transfer_buffer, RX_BUFFER_SIZE,
+ ems_usb_read_bulk_callback, dev);
+
+ retval = usb_submit_urb(urb, GFP_ATOMIC);
+
+ if (retval == -ENODEV)
+ netif_device_detach(netdev);
+ else if (retval)
+ netdev_err(netdev,
+ "failed resubmitting read bulk urb: %d\n", retval);
+}
+
+/*
+ * callback for bulk IN urb
+ */
+static void ems_usb_write_bulk_callback(struct urb *urb)
+{
+ struct ems_tx_urb_context *context = urb->context;
+ struct ems_usb *dev;
+ struct net_device *netdev;
+
+ BUG_ON(!context);
+
+ dev = context->dev;
+ netdev = dev->netdev;
+
+ /* free up our allocated buffer */
+ usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+ urb->transfer_buffer, urb->transfer_dma);
+
+ atomic_dec(&dev->active_tx_urbs);
+
+ if (!netif_device_present(netdev))
+ return;
+
+ if (urb->status)
+ netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
+
+ netdev->trans_start = jiffies;
+
+ /* transmission complete interrupt */
+ netdev->stats.tx_packets++;
+ netdev->stats.tx_bytes += context->dlc;
+
+ can_get_echo_skb(netdev, context->echo_index);
+
+ /* Release context */
+ context->echo_index = MAX_TX_URBS;
+
+ if (netif_queue_stopped(netdev))
+ netif_wake_queue(netdev);
+}
+
+/*
+ * Send the given CPC command synchronously
+ */
+static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
+{
+ int actual_length;
+
+ /* Copy payload */
+ memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
+ msg->length + CPC_MSG_HEADER_LEN);
+
+ /* Clear header */
+ memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
+
+ return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
+ &dev->tx_msg_buffer[0],
+ msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
+ &actual_length, 1000);
+}
+
+/*
+ * Change CAN controllers' mode register
+ */
+static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
+{
+ dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
+
+ return ems_usb_command_msg(dev, &dev->active_params);
+}
+
+/*
+ * Send a CPC_Control command to change behaviour when interface receives a CAN
+ * message, bus error or CAN state changed notifications.
+ */
+static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
+{
+ struct ems_cpc_msg cmd;
+
+ cmd.type = CPC_CMD_TYPE_CONTROL;
+ cmd.length = CPC_MSG_HEADER_LEN + 1;
+
+ cmd.msgid = 0;
+
+ cmd.msg.generic[0] = val;
+
+ return ems_usb_command_msg(dev, &cmd);
+}
+
+/*
+ * Start interface
+ */
+static int ems_usb_start(struct ems_usb *dev)
+{
+ struct net_device *netdev = dev->netdev;
+ int err, i;
+
+ dev->intr_in_buffer[0] = 0;
+ dev->free_slots = 15; /* initial size */
+
+ for (i = 0; i < MAX_RX_URBS; i++) {
+ struct urb *urb = NULL;
+ u8 *buf = NULL;
+
+ /* create a URB, and a buffer for it */
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb) {
+ netdev_err(netdev, "No memory left for URBs\n");
+ err = -ENOMEM;
+ break;
+ }
+
+ buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
+ &urb->transfer_dma);
+ if (!buf) {
+ netdev_err(netdev, "No memory left for USB buffer\n");
+ usb_free_urb(urb);
+ err = -ENOMEM;
+ break;
+ }
+
+ usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
+ buf, RX_BUFFER_SIZE,
+ ems_usb_read_bulk_callback, dev);
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ usb_anchor_urb(urb, &dev->rx_submitted);
+
+ err = usb_submit_urb(urb, GFP_KERNEL);
+ if (err) {
+ usb_unanchor_urb(urb);
+ usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
+ urb->transfer_dma);
+ usb_free_urb(urb);
+ break;
+ }
+
+ /* Drop reference, USB core will take care of freeing it */
+ usb_free_urb(urb);
+ }
+
+ /* Did we submit any URBs */
+ if (i == 0) {
+ netdev_warn(netdev, "couldn't setup read URBs\n");
+ return err;
+ }
+
+ /* Warn if we've couldn't transmit all the URBs */
+ if (i < MAX_RX_URBS)
+ netdev_warn(netdev, "rx performance may be slow\n");
+
+ /* Setup and start interrupt URB */
+ usb_fill_int_urb(dev->intr_urb, dev->udev,
+ usb_rcvintpipe(dev->udev, 1),
+ dev->intr_in_buffer,
+ INTR_IN_BUFFER_SIZE,
+ ems_usb_read_interrupt_callback, dev, 1);
+
+ err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
+ if (err) {
+ netdev_warn(netdev, "intr URB submit failed: %d\n", err);
+
+ return err;
+ }
+
+ /* CPC-USB will transfer received message to host */
+ err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
+ if (err)
+ goto failed;
+
+ /* CPC-USB will transfer CAN state changes to host */
+ err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
+ if (err)
+ goto failed;
+
+ /* CPC-USB will transfer bus errors to host */
+ err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
+ if (err)
+ goto failed;
+
+ err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
+ if (err)
+ goto failed;
+
+ dev->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ return 0;
+
+failed:
+ netdev_warn(netdev, "couldn't submit control: %d\n", err);
+
+ return err;
+}
+
+static void unlink_all_urbs(struct ems_usb *dev)
+{
+ int i;
+
+ usb_unlink_urb(dev->intr_urb);
+
+ usb_kill_anchored_urbs(&dev->rx_submitted);
+
+ usb_kill_anchored_urbs(&dev->tx_submitted);
+ atomic_set(&dev->active_tx_urbs, 0);
+
+ for (i = 0; i < MAX_TX_URBS; i++)
+ dev->tx_contexts[i].echo_index = MAX_TX_URBS;
+}
+
+static int ems_usb_open(struct net_device *netdev)
+{
+ struct ems_usb *dev = netdev_priv(netdev);
+ int err;
+
+ err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
+ if (err)
+ return err;
+
+ /* common open */
+ err = open_candev(netdev);
+ if (err)
+ return err;
+
+ /* finally start device */
+ err = ems_usb_start(dev);
+ if (err) {
+ if (err == -ENODEV)
+ netif_device_detach(dev->netdev);
+
+ netdev_warn(netdev, "couldn't start device: %d\n", err);
+
+ close_candev(netdev);
+
+ return err;
+ }
+
+
+ netif_start_queue(netdev);
+
+ return 0;
+}
+
+static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+ struct ems_usb *dev = netdev_priv(netdev);
+ struct ems_tx_urb_context *context = NULL;
+ struct net_device_stats *stats = &netdev->stats;
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ struct ems_cpc_msg *msg;
+ struct urb *urb;
+ u8 *buf;
+ int i, err;
+ size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
+ + sizeof(struct cpc_can_msg);
+
+ if (can_dropped_invalid_skb(netdev, skb))
+ return NETDEV_TX_OK;
+
+ /* create a URB, and a buffer for it, and copy the data to the URB */
+ urb = usb_alloc_urb(0, GFP_ATOMIC);
+ if (!urb) {
+ netdev_err(netdev, "No memory left for URBs\n");
+ goto nomem;
+ }
+
+ buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
+ if (!buf) {
+ netdev_err(netdev, "No memory left for USB buffer\n");
+ usb_free_urb(urb);
+ goto nomem;
+ }
+
+ msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
+
+ msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
+ msg->msg.can_msg.length = cf->can_dlc;
+
+ if (cf->can_id & CAN_RTR_FLAG) {
+ msg->type = cf->can_id & CAN_EFF_FLAG ?
+ CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
+
+ msg->length = CPC_CAN_MSG_MIN_SIZE;
+ } else {
+ msg->type = cf->can_id & CAN_EFF_FLAG ?
+ CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
+
+ for (i = 0; i < cf->can_dlc; i++)
+ msg->msg.can_msg.msg[i] = cf->data[i];
+
+ msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
+ }
+
+ for (i = 0; i < MAX_TX_URBS; i++) {
+ if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
+ context = &dev->tx_contexts[i];
+ break;
+ }
+ }
+
+ /*
+ * May never happen! When this happens we'd more URBs in flight as
+ * allowed (MAX_TX_URBS).
+ */
+ if (!context) {
+ usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
+ usb_free_urb(urb);
+
+ netdev_warn(netdev, "couldn't find free context\n");
+
+ return NETDEV_TX_BUSY;
+ }
+
+ context->dev = dev;
+ context->echo_index = i;
+ context->dlc = cf->can_dlc;
+
+ usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
+ size, ems_usb_write_bulk_callback, context);
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ usb_anchor_urb(urb, &dev->tx_submitted);
+
+ can_put_echo_skb(skb, netdev, context->echo_index);
+
+ atomic_inc(&dev->active_tx_urbs);
+
+ err = usb_submit_urb(urb, GFP_ATOMIC);
+ if (unlikely(err)) {
+ can_free_echo_skb(netdev, context->echo_index);
+
+ usb_unanchor_urb(urb);
+ usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
+ dev_kfree_skb(skb);
+
+ atomic_dec(&dev->active_tx_urbs);
+
+ if (err == -ENODEV) {
+ netif_device_detach(netdev);
+ } else {
+ netdev_warn(netdev, "failed tx_urb %d\n", err);
+
+ stats->tx_dropped++;
+ }
+ } else {
+ netdev->trans_start = jiffies;
+
+ /* Slow down tx path */
+ if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
+ dev->free_slots < 5) {
+ netif_stop_queue(netdev);
+ }
+ }
+
+ /*
+ * Release our reference to this URB, the USB core will eventually free
+ * it entirely.
+ */
+ usb_free_urb(urb);
+
+ return NETDEV_TX_OK;
+
+nomem:
+ dev_kfree_skb(skb);
+ stats->tx_dropped++;
+
+ return NETDEV_TX_OK;
+}
+
+static int ems_usb_close(struct net_device *netdev)
+{
+ struct ems_usb *dev = netdev_priv(netdev);
+
+ /* Stop polling */
+ unlink_all_urbs(dev);
+
+ netif_stop_queue(netdev);
+
+ /* Set CAN controller to reset mode */
+ if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
+ netdev_warn(netdev, "couldn't stop device");
+
+ close_candev(netdev);
+
+ return 0;
+}
+
+static const struct net_device_ops ems_usb_netdev_ops = {
+ .ndo_open = ems_usb_open,
+ .ndo_stop = ems_usb_close,
+ .ndo_start_xmit = ems_usb_start_xmit,
+ .ndo_change_mtu = can_change_mtu,
+};
+
+static const struct can_bittiming_const ems_usb_bittiming_const = {
+ .name = "ems_usb",
+ .tseg1_min = 1,
+ .tseg1_max = 16,
+ .tseg2_min = 1,
+ .tseg2_max = 8,
+ .sjw_max = 4,
+ .brp_min = 1,
+ .brp_max = 64,
+ .brp_inc = 1,
+};
+
+static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
+{
+ struct ems_usb *dev = netdev_priv(netdev);
+
+ switch (mode) {
+ case CAN_MODE_START:
+ if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
+ netdev_warn(netdev, "couldn't start device");
+
+ if (netif_queue_stopped(netdev))
+ netif_wake_queue(netdev);
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int ems_usb_set_bittiming(struct net_device *netdev)
+{
+ struct ems_usb *dev = netdev_priv(netdev);
+ struct can_bittiming *bt = &dev->can.bittiming;
+ u8 btr0, btr1;
+
+ btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
+ btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
+ (((bt->phase_seg2 - 1) & 0x7) << 4);
+ if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+ btr1 |= 0x80;
+
+ netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
+
+ dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
+ dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
+
+ return ems_usb_command_msg(dev, &dev->active_params);
+}
+
+static void init_params_sja1000(struct ems_cpc_msg *msg)
+{
+ struct cpc_sja1000_params *sja1000 =
+ &msg->msg.can_params.cc_params.sja1000;
+
+ msg->type = CPC_CMD_TYPE_CAN_PARAMS;
+ msg->length = sizeof(struct cpc_can_params);
+ msg->msgid = 0;
+
+ msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
+
+ /* Acceptance filter open */
+ sja1000->acc_code0 = 0x00;
+ sja1000->acc_code1 = 0x00;
+ sja1000->acc_code2 = 0x00;
+ sja1000->acc_code3 = 0x00;
+
+ /* Acceptance filter open */
+ sja1000->acc_mask0 = 0xFF;
+ sja1000->acc_mask1 = 0xFF;
+ sja1000->acc_mask2 = 0xFF;
+ sja1000->acc_mask3 = 0xFF;
+
+ sja1000->btr0 = 0;
+ sja1000->btr1 = 0;
+
+ sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
+ sja1000->mode = SJA1000_MOD_RM;
+}
+
+/*
+ * probe function for new CPC-USB devices
+ */
+static int ems_usb_probe(struct usb_interface *intf,
+ const struct usb_device_id *id)
+{
+ struct net_device *netdev;
+ struct ems_usb *dev;
+ int i, err = -ENOMEM;
+
+ netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
+ if (!netdev) {
+ dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
+ return -ENOMEM;
+ }
+
+ dev = netdev_priv(netdev);
+
+ dev->udev = interface_to_usbdev(intf);
+ dev->netdev = netdev;
+
+ dev->can.state = CAN_STATE_STOPPED;
+ dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
+ dev->can.bittiming_const = &ems_usb_bittiming_const;
+ dev->can.do_set_bittiming = ems_usb_set_bittiming;
+ dev->can.do_set_mode = ems_usb_set_mode;
+ dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
+
+ netdev->netdev_ops = &ems_usb_netdev_ops;
+
+ netdev->flags |= IFF_ECHO; /* we support local echo */
+
+ init_usb_anchor(&dev->rx_submitted);
+
+ init_usb_anchor(&dev->tx_submitted);
+ atomic_set(&dev->active_tx_urbs, 0);
+
+ for (i = 0; i < MAX_TX_URBS; i++)
+ dev->tx_contexts[i].echo_index = MAX_TX_URBS;
+
+ dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!dev->intr_urb) {
+ dev_err(&intf->dev, "Couldn't alloc intr URB\n");
+ goto cleanup_candev;
+ }
+
+ dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
+ if (!dev->intr_in_buffer)
+ goto cleanup_intr_urb;
+
+ dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
+ sizeof(struct ems_cpc_msg), GFP_KERNEL);
+ if (!dev->tx_msg_buffer)
+ goto cleanup_intr_in_buffer;
+
+ usb_set_intfdata(intf, dev);
+
+ SET_NETDEV_DEV(netdev, &intf->dev);
+
+ init_params_sja1000(&dev->active_params);
+
+ err = ems_usb_command_msg(dev, &dev->active_params);
+ if (err) {
+ netdev_err(netdev, "couldn't initialize controller: %d\n", err);
+ goto cleanup_tx_msg_buffer;
+ }
+
+ err = register_candev(netdev);
+ if (err) {
+ netdev_err(netdev, "couldn't register CAN device: %d\n", err);
+ goto cleanup_tx_msg_buffer;
+ }
+
+ return 0;
+
+cleanup_tx_msg_buffer:
+ kfree(dev->tx_msg_buffer);
+
+cleanup_intr_in_buffer:
+ kfree(dev->intr_in_buffer);
+
+cleanup_intr_urb:
+ usb_free_urb(dev->intr_urb);
+
+cleanup_candev:
+ free_candev(netdev);
+
+ return err;
+}
+
+/*
+ * called by the usb core when the device is removed from the system
+ */
+static void ems_usb_disconnect(struct usb_interface *intf)
+{
+ struct ems_usb *dev = usb_get_intfdata(intf);
+
+ usb_set_intfdata(intf, NULL);
+
+ if (dev) {
+ unregister_netdev(dev->netdev);
+ free_candev(dev->netdev);
+
+ unlink_all_urbs(dev);
+
+ usb_free_urb(dev->intr_urb);
+
+ kfree(dev->intr_in_buffer);
+ }
+}
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver ems_usb_driver = {
+ .name = "ems_usb",
+ .probe = ems_usb_probe,
+ .disconnect = ems_usb_disconnect,
+ .id_table = ems_usb_table,
+};
+
+module_usb_driver(ems_usb_driver);
Code Review / kvmfornfv.git / blobdiff