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linux/drivers/net/can/usb/ems_usb.c
Thomas Gleixner 935912c538 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 164 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 12 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.745497013@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:38 -07:00

1076 lines
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// 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);
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