diff options
Diffstat (limited to 'drivers/net/can/usb/ems_usb.c')
| -rw-r--r-- | drivers/net/can/usb/ems_usb.c | 1155 |
1 files changed, 1155 insertions, 0 deletions
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c new file mode 100644 index 00000000000..9012e0abc62 --- /dev/null +++ b/drivers/net/can/usb/ems_usb.c @@ -0,0 +1,1155 @@ +/* + * 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/init.h> +#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 { + u32 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 __attribute__ ((packed)) ems_cpc_msg { + u8 type; /* type of message */ + u8 length; /* length of data within union 'msg' */ + u8 msgid; /* confirmation handle */ + u32 ts_sec; /* timestamp in seconds */ + u32 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 CAN_ECHO_SKB_MAX + +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 */ + int open_time; + + 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: + dev_info(netdev->dev.parent, "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) + dev_err(netdev->dev.parent, + "failed resubmitting intr urb: %d\n", err); + + return; +} + +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 = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame)); + if (skb == NULL) + return; + + skb->protocol = htons(ETH_P_CAN); + + cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); + + cf->can_id = msg->msg.can_msg.id; + cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8); + + 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 = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame)); + if (skb == NULL) + return; + + skb->protocol = htons(ETH_P_CAN); + + cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); + memset(cf, 0, sizeof(struct can_frame)); + + cf->can_id = CAN_ERR_FLAG; + cf->can_dlc = CAN_ERR_DLC; + + 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; + + 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 occured 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: + dev_info(netdev->dev.parent, "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, again, start; + + msg_count = ibuf[0] & ~0x80; + again = 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) { + dev_err(netdev->dev.parent, "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) + dev_err(netdev->dev.parent, + "failed resubmitting read bulk urb: %d\n", retval); + + return; +} + +/* + * 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_buffer_free(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) + dev_info(netdev->dev.parent, "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) { + dev_err(netdev->dev.parent, + "No memory left for URBs\n"); + return -ENOMEM; + } + + buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, + &urb->transfer_dma); + if (!buf) { + dev_err(netdev->dev.parent, + "No memory left for USB buffer\n"); + usb_free_urb(urb); + return -ENOMEM; + } + + 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) { + if (err == -ENODEV) + netif_device_detach(dev->netdev); + + usb_unanchor_urb(urb); + usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf, + urb->transfer_dma); + break; + } + + /* Drop reference, USB core will take care of freeing it */ + usb_free_urb(urb); + } + + /* Did we submit any URBs */ + if (i == 0) { + dev_warn(netdev->dev.parent, "couldn't setup read URBs\n"); + return err; + } + + /* Warn if we've couldn't transmit all the URBs */ + if (i < MAX_RX_URBS) + dev_warn(netdev->dev.parent, "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) { + if (err == -ENODEV) + netif_device_detach(dev->netdev); + + dev_warn(netdev->dev.parent, "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: + if (err == -ENODEV) + netif_device_detach(dev->netdev); + + dev_warn(netdev->dev.parent, "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); + + dev_warn(netdev->dev.parent, "couldn't start device: %d\n", + err); + + close_candev(netdev); + + return err; + } + + dev->open_time = jiffies; + + 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); + + /* create a URB, and a buffer for it, and copy the data to the URB */ + urb = usb_alloc_urb(0, GFP_ATOMIC); + if (!urb) { + dev_err(netdev->dev.parent, "No memory left for URBs\n"); + goto nomem; + } + + buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); + if (!buf) { + dev_err(netdev->dev.parent, "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 = 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_unanchor_urb(urb); + usb_buffer_free(dev->udev, size, buf, urb->transfer_dma); + + dev_warn(netdev->dev.parent, "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_buffer_free(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 { + dev_warn(netdev->dev.parent, "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: + if (skb) + 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)) + dev_warn(netdev->dev.parent, "couldn't stop device"); + + close_candev(netdev); + + dev->open_time = 0; + + 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, +}; + +static 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); + + if (!dev->open_time) + return -EINVAL; + + switch (mode) { + case CAN_MODE_START: + if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) + dev_warn(netdev->dev.parent, "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; + + dev_info(netdev->dev.parent, "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)); + if (!netdev) { + dev_err(netdev->dev.parent, "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; + + netdev->flags |= IFF_ECHO; /* we support local echo */ + + 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(netdev->dev.parent, "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) { + dev_err(netdev->dev.parent, "Couldn't alloc Intr buffer\n"); + goto cleanup_intr_urb; + } + + dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + + sizeof(struct ems_cpc_msg), GFP_KERNEL); + if (!dev->tx_msg_buffer) { + dev_err(netdev->dev.parent, "Couldn't alloc Tx buffer\n"); + 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) { + dev_err(netdev->dev.parent, + "couldn't initialize controller: %d\n", err); + goto cleanup_tx_msg_buffer; + } + + err = register_candev(netdev); + if (err) { + dev_err(netdev->dev.parent, + "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, +}; + +static int __init ems_usb_init(void) +{ + int err; + + printk(KERN_INFO "CPC-USB kernel driver loaded\n"); + + /* register this driver with the USB subsystem */ + err = usb_register(&ems_usb_driver); + + if (err) { + err("usb_register failed. Error number %d\n", err); + return err; + } + + return 0; +} + +static void __exit ems_usb_exit(void) +{ + /* deregister this driver with the USB subsystem */ + usb_deregister(&ems_usb_driver); +} + +module_init(ems_usb_init); +module_exit(ems_usb_exit); |