// SPDX-License-Identifier: GPL-2.0-only
/*
* CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
*
* Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
*/
#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
#define CPC_TX_QUEUE_TRIGGER_LOW 25
#define CPC_TX_QUEUE_TRIGGER_HIGH 35
/*
* 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];
if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
netif_queue_stopped(netdev))
netif_wake_queue(netdev);
break;
case -ECONNRESET: /* unlink */
case -ENOENT:
case -EPIPE:
case -EPROTO:
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];
}
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_rx(skb);
}
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[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->can_id |= CAN_ERR_CRTL;
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++;
}
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_rx(skb);
}
/*
* 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);
netif_trans_update(netdev);
/* 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;
}
/*
* 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 = 50; /* 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) {
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)
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 {
netif_trans_update(netdev);
/* Slow down tx path */
if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
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)
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);
kfree(dev->tx_msg_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);