// 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 #include #include #include #include #include #include #include MODULE_AUTHOR("Sebastian Haas "); 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; }; 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 */ void *rxbuf[MAX_RX_URBS]; dma_addr_t rxbuf_dma[MAX_RX_URBS]; }; 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->len = can_cc_dlc2len(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->len; i++) cf->data[i] = msg->msg.can_msg.msg[i]; stats->rx_bytes += cf->len; } stats->rx_packets++; 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++; } 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 += can_get_echo_skb(netdev, context->echo_index, NULL); /* 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; dma_addr_t buf_dma; /* 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, &buf_dma); if (!buf) { netdev_err(netdev, "No memory left for USB buffer\n"); usb_free_urb(urb); err = -ENOMEM; break; } urb->transfer_dma = buf_dma; 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; } dev->rxbuf[i] = buf; dev->rxbuf_dma[i] = buf_dma; /* 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); for (i = 0; i < MAX_RX_URBS; ++i) usb_free_coherent(dev->udev, RX_BUFFER_SIZE, dev->rxbuf[i], dev->rxbuf_dma[i]); 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->len; 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->len; i++) msg->msg.can_msg.msg[i] = cf->data[i]; msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; } 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; 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, 0); atomic_inc(&dev->active_tx_urbs); err = usb_submit_urb(urb, GFP_ATOMIC); if (unlikely(err)) { can_free_echo_skb(netdev, context->echo_index, NULL); usb_unanchor_urb(urb); usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 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); unlink_all_urbs(dev); usb_free_urb(dev->intr_urb); kfree(dev->intr_in_buffer); kfree(dev->tx_msg_buffer); free_candev(dev->netdev); } } /* 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);