| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jakob Unterwurzacher | 5815 | 98.49% | 1 | 4.35% |
| Vincent Mailhol | 23 | 0.39% | 3 | 13.04% |
| Anssi Hannula | 11 | 0.19% | 1 | 4.35% |
| Oliver Hartkopp | 11 | 0.19% | 3 | 13.04% |
| Marc Kleine-Budde | 10 | 0.17% | 3 | 13.04% |
| Jeppe Ledet-Pedersen | 8 | 0.14% | 1 | 4.35% |
| Gustavo A. R. Silva | 6 | 0.10% | 1 | 4.35% |
| Maximilian Schneider | 6 | 0.10% | 2 | 8.70% |
| Arnd Bergmann | 4 | 0.07% | 1 | 4.35% |
| xupanda | 3 | 0.05% | 1 | 4.35% |
| Julia Lawall | 2 | 0.03% | 1 | 4.35% |
| Johan Hovold | 1 | 0.02% | 1 | 4.35% |
| Jakub Kiciński | 1 | 0.02% | 1 | 4.35% |
| Mao Zhu | 1 | 0.02% | 1 | 4.35% |
| Dongliang Mu | 1 | 0.02% | 1 | 4.35% |
| Colin Ian King | 1 | 0.02% | 1 | 4.35% |
| Total | 5904 | 23 |
// SPDX-License-Identifier: GPL-2.0 /* Driver for Theobroma Systems UCAN devices, Protocol Version 3 * * Copyright (C) 2018 Theobroma Systems Design und Consulting GmbH * * * General Description: * * The USB Device uses three Endpoints: * * CONTROL Endpoint: Is used the setup the device (start, stop, * info, configure). * * IN Endpoint: The device sends CAN Frame Messages and Device * Information using the IN endpoint. * * OUT Endpoint: The driver sends configuration requests, and CAN * Frames on the out endpoint. * * Error Handling: * * If error reporting is turned on the device encodes error into CAN * error frames (see uapi/linux/can/error.h) and sends it using the * IN Endpoint. The driver updates statistics and forward it. */ #include <linux/can.h> #include <linux/can/dev.h> #include <linux/can/error.h> #include <linux/ethtool.h> #include <linux/module.h> #include <linux/netdevice.h> #include <linux/signal.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/usb.h> #define UCAN_DRIVER_NAME "ucan" #define UCAN_MAX_RX_URBS 8 /* the CAN controller needs a while to enable/disable the bus */ #define UCAN_USB_CTL_PIPE_TIMEOUT 1000 /* this driver currently supports protocol version 3 only */ #define UCAN_PROTOCOL_VERSION_MIN 3 #define UCAN_PROTOCOL_VERSION_MAX 3 /* UCAN Message Definitions * ------------------------ * * ucan_message_out_t and ucan_message_in_t define the messages * transmitted on the OUT and IN endpoint. * * Multibyte fields are transmitted with little endianness * * INTR Endpoint: a single uint32_t storing the current space in the fifo * * OUT Endpoint: single message of type ucan_message_out_t is * transmitted on the out endpoint * * IN Endpoint: multiple messages ucan_message_in_t concateted in * the following way: * * m[n].len <=> the length if message n(including the header in bytes) * m[n] is is aligned to a 4 byte boundary, hence * offset(m[0]) := 0; * offset(m[n+1]) := offset(m[n]) + (m[n].len + 3) & 3 * * this implies that * offset(m[n]) % 4 <=> 0 */ /* Device Global Commands */ enum { UCAN_DEVICE_GET_FW_STRING = 0, }; /* UCAN Commands */ enum { /* start the can transceiver - val defines the operation mode */ UCAN_COMMAND_START = 0, /* cancel pending transmissions and stop the can transceiver */ UCAN_COMMAND_STOP = 1, /* send can transceiver into low-power sleep mode */ UCAN_COMMAND_SLEEP = 2, /* wake up can transceiver from low-power sleep mode */ UCAN_COMMAND_WAKEUP = 3, /* reset the can transceiver */ UCAN_COMMAND_RESET = 4, /* get piece of info from the can transceiver - subcmd defines what * piece */ UCAN_COMMAND_GET = 5, /* clear or disable hardware filter - subcmd defines which of the two */ UCAN_COMMAND_FILTER = 6, /* Setup bittiming */ UCAN_COMMAND_SET_BITTIMING = 7, /* recover from bus-off state */ UCAN_COMMAND_RESTART = 8, }; /* UCAN_COMMAND_START and UCAN_COMMAND_GET_INFO operation modes (bitmap). * Undefined bits must be set to 0. */ enum { UCAN_MODE_LOOPBACK = BIT(0), UCAN_MODE_SILENT = BIT(1), UCAN_MODE_3_SAMPLES = BIT(2), UCAN_MODE_ONE_SHOT = BIT(3), UCAN_MODE_BERR_REPORT = BIT(4), }; /* UCAN_COMMAND_GET subcommands */ enum { UCAN_COMMAND_GET_INFO = 0, UCAN_COMMAND_GET_PROTOCOL_VERSION = 1, }; /* UCAN_COMMAND_FILTER subcommands */ enum { UCAN_FILTER_CLEAR = 0, UCAN_FILTER_DISABLE = 1, UCAN_FILTER_ENABLE = 2, }; /* OUT endpoint message types */ enum { UCAN_OUT_TX = 2, /* transmit a CAN frame */ }; /* IN endpoint message types */ enum { UCAN_IN_TX_COMPLETE = 1, /* CAN frame transmission completed */ UCAN_IN_RX = 2, /* CAN frame received */ }; struct ucan_ctl_cmd_start { __le16 mode; /* OR-ing any of UCAN_MODE_* */ } __packed; struct ucan_ctl_cmd_set_bittiming { __le32 tq; /* Time quanta (TQ) in nanoseconds */ __le16 brp; /* TQ Prescaler */ __le16 sample_point; /* Samplepoint on tenth percent */ u8 prop_seg; /* Propagation segment in TQs */ u8 phase_seg1; /* Phase buffer segment 1 in TQs */ u8 phase_seg2; /* Phase buffer segment 2 in TQs */ u8 sjw; /* Synchronisation jump width in TQs */ } __packed; struct ucan_ctl_cmd_device_info { __le32 freq; /* Clock Frequency for tq generation */ u8 tx_fifo; /* Size of the transmission fifo */ u8 sjw_max; /* can_bittiming fields... */ u8 tseg1_min; u8 tseg1_max; u8 tseg2_min; u8 tseg2_max; __le16 brp_inc; __le32 brp_min; __le32 brp_max; /* ...can_bittiming fields */ __le16 ctrlmodes; /* supported control modes */ __le16 hwfilter; /* Number of HW filter banks */ __le16 rxmboxes; /* Number of receive Mailboxes */ } __packed; struct ucan_ctl_cmd_get_protocol_version { __le32 version; } __packed; union ucan_ctl_payload { /* Setup Bittiming * bmRequest == UCAN_COMMAND_START */ struct ucan_ctl_cmd_start cmd_start; /* Setup Bittiming * bmRequest == UCAN_COMMAND_SET_BITTIMING */ struct ucan_ctl_cmd_set_bittiming cmd_set_bittiming; /* Get Device Information * bmRequest == UCAN_COMMAND_GET; wValue = UCAN_COMMAND_GET_INFO */ struct ucan_ctl_cmd_device_info cmd_get_device_info; /* Get Protocol Version * bmRequest == UCAN_COMMAND_GET; * wValue = UCAN_COMMAND_GET_PROTOCOL_VERSION */ struct ucan_ctl_cmd_get_protocol_version cmd_get_protocol_version; u8 raw[128]; } __packed; enum { UCAN_TX_COMPLETE_SUCCESS = BIT(0), }; /* Transmission Complete within ucan_message_in */ struct ucan_tx_complete_entry_t { u8 echo_index; u8 flags; } __packed __aligned(0x2); /* CAN Data message format within ucan_message_in/out */ struct ucan_can_msg { /* note DLC is computed by * msg.len - sizeof (msg.len) * - sizeof (msg.type) * - sizeof (msg.can_msg.id) */ __le32 id; union { u8 data[CAN_MAX_DLEN]; /* Data of CAN frames */ u8 dlc; /* RTR dlc */ }; } __packed; /* OUT Endpoint, outbound messages */ struct ucan_message_out { __le16 len; /* Length of the content include header */ u8 type; /* UCAN_OUT_TX and friends */ u8 subtype; /* command sub type */ union { /* Transmit CAN frame * (type == UCAN_TX) && ((msg.can_msg.id & CAN_RTR_FLAG) == 0) * subtype stores the echo id */ struct ucan_can_msg can_msg; } msg; } __packed __aligned(0x4); /* IN Endpoint, inbound messages */ struct ucan_message_in { __le16 len; /* Length of the content include header */ u8 type; /* UCAN_IN_RX and friends */ u8 subtype; /* command sub type */ union { /* CAN Frame received * (type == UCAN_IN_RX) * && ((msg.can_msg.id & CAN_RTR_FLAG) == 0) */ struct ucan_can_msg can_msg; /* CAN transmission complete * (type == UCAN_IN_TX_COMPLETE) */ DECLARE_FLEX_ARRAY(struct ucan_tx_complete_entry_t, can_tx_complete_msg); } __aligned(0x4) msg; } __packed __aligned(0x4); /* Macros to calculate message lengths */ #define UCAN_OUT_HDR_SIZE offsetof(struct ucan_message_out, msg) #define UCAN_IN_HDR_SIZE offsetof(struct ucan_message_in, msg) #define UCAN_IN_LEN(member) (UCAN_OUT_HDR_SIZE + sizeof(member)) struct ucan_priv; /* Context Information for transmission URBs */ struct ucan_urb_context { struct ucan_priv *up; bool allocated; }; /* Information reported by the USB device */ struct ucan_device_info { struct can_bittiming_const bittiming_const; u8 tx_fifo; }; /* Driver private data */ struct ucan_priv { /* must be the first member */ struct can_priv can; /* linux USB device structures */ struct usb_device *udev; struct net_device *netdev; /* lock for can->echo_skb (used around * can_put/get/free_echo_skb */ spinlock_t echo_skb_lock; /* usb device information */ u8 intf_index; u8 in_ep_addr; u8 out_ep_addr; u16 in_ep_size; /* transmission and reception buffers */ struct usb_anchor rx_urbs; struct usb_anchor tx_urbs; union ucan_ctl_payload *ctl_msg_buffer; struct ucan_device_info device_info; /* transmission control information and locks */ spinlock_t context_lock; unsigned int available_tx_urbs; struct ucan_urb_context *context_array; }; static u8 ucan_can_cc_dlc2len(struct ucan_can_msg *msg, u16 len) { if (le32_to_cpu(msg->id) & CAN_RTR_FLAG) return can_cc_dlc2len(msg->dlc); else return can_cc_dlc2len(len - (UCAN_IN_HDR_SIZE + sizeof(msg->id))); } static void ucan_release_context_array(struct ucan_priv *up) { if (!up->context_array) return; /* lock is not needed because, driver is currently opening or closing */ up->available_tx_urbs = 0; kfree(up->context_array); up->context_array = NULL; } static int ucan_alloc_context_array(struct ucan_priv *up) { int i; /* release contexts if any */ ucan_release_context_array(up); up->context_array = kcalloc(up->device_info.tx_fifo, sizeof(*up->context_array), GFP_KERNEL); if (!up->context_array) { netdev_err(up->netdev, "Not enough memory to allocate tx contexts\n"); return -ENOMEM; } for (i = 0; i < up->device_info.tx_fifo; i++) { up->context_array[i].allocated = false; up->context_array[i].up = up; } /* lock is not needed because, driver is currently opening */ up->available_tx_urbs = up->device_info.tx_fifo; return 0; } static struct ucan_urb_context *ucan_alloc_context(struct ucan_priv *up) { int i; unsigned long flags; struct ucan_urb_context *ret = NULL; if (WARN_ON_ONCE(!up->context_array)) return NULL; /* execute context operation atomically */ spin_lock_irqsave(&up->context_lock, flags); for (i = 0; i < up->device_info.tx_fifo; i++) { if (!up->context_array[i].allocated) { /* update context */ ret = &up->context_array[i]; up->context_array[i].allocated = true; /* stop queue if necessary */ up->available_tx_urbs--; if (!up->available_tx_urbs) netif_stop_queue(up->netdev); break; } } spin_unlock_irqrestore(&up->context_lock, flags); return ret; } static bool ucan_release_context(struct ucan_priv *up, struct ucan_urb_context *ctx) { unsigned long flags; bool ret = false; if (WARN_ON_ONCE(!up->context_array)) return false; /* execute context operation atomically */ spin_lock_irqsave(&up->context_lock, flags); /* context was not allocated, maybe the device sent garbage */ if (ctx->allocated) { ctx->allocated = false; /* check if the queue needs to be woken */ if (!up->available_tx_urbs) netif_wake_queue(up->netdev); up->available_tx_urbs++; ret = true; } spin_unlock_irqrestore(&up->context_lock, flags); return ret; } static int ucan_ctrl_command_out(struct ucan_priv *up, u8 cmd, u16 subcmd, u16 datalen) { return usb_control_msg(up->udev, usb_sndctrlpipe(up->udev, 0), cmd, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE, subcmd, up->intf_index, up->ctl_msg_buffer, datalen, UCAN_USB_CTL_PIPE_TIMEOUT); } static int ucan_device_request_in(struct ucan_priv *up, u8 cmd, u16 subcmd, u16 datalen) { return usb_control_msg(up->udev, usb_rcvctrlpipe(up->udev, 0), cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, subcmd, 0, up->ctl_msg_buffer, datalen, UCAN_USB_CTL_PIPE_TIMEOUT); } /* Parse the device information structure reported by the device and * setup private variables accordingly */ static void ucan_parse_device_info(struct ucan_priv *up, struct ucan_ctl_cmd_device_info *device_info) { struct can_bittiming_const *bittiming = &up->device_info.bittiming_const; u16 ctrlmodes; /* store the data */ up->can.clock.freq = le32_to_cpu(device_info->freq); up->device_info.tx_fifo = device_info->tx_fifo; strcpy(bittiming->name, "ucan"); bittiming->tseg1_min = device_info->tseg1_min; bittiming->tseg1_max = device_info->tseg1_max; bittiming->tseg2_min = device_info->tseg2_min; bittiming->tseg2_max = device_info->tseg2_max; bittiming->sjw_max = device_info->sjw_max; bittiming->brp_min = le32_to_cpu(device_info->brp_min); bittiming->brp_max = le32_to_cpu(device_info->brp_max); bittiming->brp_inc = le16_to_cpu(device_info->brp_inc); ctrlmodes = le16_to_cpu(device_info->ctrlmodes); up->can.ctrlmode_supported = 0; if (ctrlmodes & UCAN_MODE_LOOPBACK) up->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK; if (ctrlmodes & UCAN_MODE_SILENT) up->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY; if (ctrlmodes & UCAN_MODE_3_SAMPLES) up->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES; if (ctrlmodes & UCAN_MODE_ONE_SHOT) up->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT; if (ctrlmodes & UCAN_MODE_BERR_REPORT) up->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING; } /* Handle a CAN error frame that we have received from the device. * Returns true if the can state has changed. */ static bool ucan_handle_error_frame(struct ucan_priv *up, struct ucan_message_in *m, canid_t canid) { enum can_state new_state = up->can.state; struct net_device_stats *net_stats = &up->netdev->stats; struct can_device_stats *can_stats = &up->can.can_stats; if (canid & CAN_ERR_LOSTARB) can_stats->arbitration_lost++; if (canid & CAN_ERR_BUSERROR) can_stats->bus_error++; if (canid & CAN_ERR_ACK) net_stats->tx_errors++; if (canid & CAN_ERR_BUSOFF) new_state = CAN_STATE_BUS_OFF; /* controller problems, details in data[1] */ if (canid & CAN_ERR_CRTL) { u8 d1 = m->msg.can_msg.data[1]; if (d1 & CAN_ERR_CRTL_RX_OVERFLOW) net_stats->rx_over_errors++; /* controller state bits: if multiple are set the worst wins */ if (d1 & CAN_ERR_CRTL_ACTIVE) new_state = CAN_STATE_ERROR_ACTIVE; if (d1 & (CAN_ERR_CRTL_RX_WARNING | CAN_ERR_CRTL_TX_WARNING)) new_state = CAN_STATE_ERROR_WARNING; if (d1 & (CAN_ERR_CRTL_RX_PASSIVE | CAN_ERR_CRTL_TX_PASSIVE)) new_state = CAN_STATE_ERROR_PASSIVE; } /* protocol error, details in data[2] */ if (canid & CAN_ERR_PROT) { u8 d2 = m->msg.can_msg.data[2]; if (d2 & CAN_ERR_PROT_TX) net_stats->tx_errors++; else net_stats->rx_errors++; } /* no state change - we are done */ if (up->can.state == new_state) return false; /* we switched into a better state */ if (up->can.state > new_state) { up->can.state = new_state; return true; } /* we switched into a worse state */ up->can.state = new_state; switch (new_state) { case CAN_STATE_BUS_OFF: can_stats->bus_off++; can_bus_off(up->netdev); break; case CAN_STATE_ERROR_PASSIVE: can_stats->error_passive++; break; case CAN_STATE_ERROR_WARNING: can_stats->error_warning++; break; default: break; } return true; } /* Callback on reception of a can frame via the IN endpoint * * This function allocates an skb and transferres it to the Linux * network stack */ static void ucan_rx_can_msg(struct ucan_priv *up, struct ucan_message_in *m) { int len; canid_t canid; struct can_frame *cf; struct sk_buff *skb; struct net_device_stats *stats = &up->netdev->stats; /* get the contents of the length field */ len = le16_to_cpu(m->len); /* check sanity */ if (len < UCAN_IN_HDR_SIZE + sizeof(m->msg.can_msg.id)) { netdev_warn(up->netdev, "invalid input message len: %d\n", len); return; } /* handle error frames */ canid = le32_to_cpu(m->msg.can_msg.id); if (canid & CAN_ERR_FLAG) { bool busstate_changed = ucan_handle_error_frame(up, m, canid); /* if berr-reporting is off only state changes get through */ if (!(up->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) && !busstate_changed) return; } else { canid_t canid_mask; /* compute the mask for canid */ canid_mask = CAN_RTR_FLAG; if (canid & CAN_EFF_FLAG) canid_mask |= CAN_EFF_MASK | CAN_EFF_FLAG; else canid_mask |= CAN_SFF_MASK; if (canid & ~canid_mask) netdev_warn(up->netdev, "unexpected bits set (canid %x, mask %x)", canid, canid_mask); canid &= canid_mask; } /* allocate skb */ skb = alloc_can_skb(up->netdev, &cf); if (!skb) return; /* fill the can frame */ cf->can_id = canid; /* compute DLC taking RTR_FLAG into account */ cf->len = ucan_can_cc_dlc2len(&m->msg.can_msg, len); /* copy the payload of non RTR frames */ if (!(cf->can_id & CAN_RTR_FLAG) || (cf->can_id & CAN_ERR_FLAG)) memcpy(cf->data, m->msg.can_msg.data, cf->len); /* don't count error frames as real packets */ if (!(cf->can_id & CAN_ERR_FLAG)) { stats->rx_packets++; if (!(cf->can_id & CAN_RTR_FLAG)) stats->rx_bytes += cf->len; } /* pass it to Linux */ netif_rx(skb); } /* callback indicating completed transmission */ static void ucan_tx_complete_msg(struct ucan_priv *up, struct ucan_message_in *m) { unsigned long flags; u16 count, i; u8 echo_index; u16 len = le16_to_cpu(m->len); struct ucan_urb_context *context; if (len < UCAN_IN_HDR_SIZE || (len % 2 != 0)) { netdev_err(up->netdev, "invalid tx complete length\n"); return; } count = (len - UCAN_IN_HDR_SIZE) / 2; for (i = 0; i < count; i++) { /* we did not submit such echo ids */ echo_index = m->msg.can_tx_complete_msg[i].echo_index; if (echo_index >= up->device_info.tx_fifo) { up->netdev->stats.tx_errors++; netdev_err(up->netdev, "invalid echo_index %d received\n", echo_index); continue; } /* gather information from the context */ context = &up->context_array[echo_index]; /* Release context and restart queue if necessary. * Also check if the context was allocated */ if (!ucan_release_context(up, context)) continue; spin_lock_irqsave(&up->echo_skb_lock, flags); if (m->msg.can_tx_complete_msg[i].flags & UCAN_TX_COMPLETE_SUCCESS) { /* update statistics */ up->netdev->stats.tx_packets++; up->netdev->stats.tx_bytes += can_get_echo_skb(up->netdev, echo_index, NULL); } else { up->netdev->stats.tx_dropped++; can_free_echo_skb(up->netdev, echo_index, NULL); } spin_unlock_irqrestore(&up->echo_skb_lock, flags); } } /* callback on reception of a USB message */ static void ucan_read_bulk_callback(struct urb *urb) { int ret; int pos; struct ucan_priv *up = urb->context; struct net_device *netdev = up->netdev; struct ucan_message_in *m; /* the device is not up and the driver should not receive any * data on the bulk in pipe */ if (WARN_ON(!up->context_array)) { usb_free_coherent(up->udev, up->in_ep_size, urb->transfer_buffer, urb->transfer_dma); return; } /* check URB status */ switch (urb->status) { case 0: break; case -ENOENT: case -EPIPE: case -EPROTO: case -ESHUTDOWN: case -ETIME: /* urb is not resubmitted -> free dma data */ usb_free_coherent(up->udev, up->in_ep_size, urb->transfer_buffer, urb->transfer_dma); netdev_dbg(up->netdev, "not resubmitting urb; status: %d\n", urb->status); return; default: goto resubmit; } /* sanity check */ if (!netif_device_present(netdev)) return; /* iterate over input */ pos = 0; while (pos < urb->actual_length) { int len; /* check sanity (length of header) */ if ((urb->actual_length - pos) < UCAN_IN_HDR_SIZE) { netdev_warn(up->netdev, "invalid message (short; no hdr; l:%d)\n", urb->actual_length); goto resubmit; } /* setup the message address */ m = (struct ucan_message_in *) ((u8 *)urb->transfer_buffer + pos); len = le16_to_cpu(m->len); /* check sanity (length of content) */ if (urb->actual_length - pos < len) { netdev_warn(up->netdev, "invalid message (short; no data; l:%d)\n", urb->actual_length); print_hex_dump(KERN_WARNING, "raw data: ", DUMP_PREFIX_ADDRESS, 16, 1, urb->transfer_buffer, urb->actual_length, true); goto resubmit; } switch (m->type) { case UCAN_IN_RX: ucan_rx_can_msg(up, m); break; case UCAN_IN_TX_COMPLETE: ucan_tx_complete_msg(up, m); break; default: netdev_warn(up->netdev, "invalid message (type; t:%d)\n", m->type); break; } /* proceed to next message */ pos += len; /* align to 4 byte boundary */ pos = round_up(pos, 4); } resubmit: /* resubmit urb when done */ usb_fill_bulk_urb(urb, up->udev, usb_rcvbulkpipe(up->udev, up->in_ep_addr), urb->transfer_buffer, up->in_ep_size, ucan_read_bulk_callback, up); usb_anchor_urb(urb, &up->rx_urbs); ret = usb_submit_urb(urb, GFP_ATOMIC); if (ret < 0) { netdev_err(up->netdev, "failed resubmitting read bulk urb: %d\n", ret); usb_unanchor_urb(urb); usb_free_coherent(up->udev, up->in_ep_size, urb->transfer_buffer, urb->transfer_dma); if (ret == -ENODEV) netif_device_detach(netdev); } } /* callback after transmission of a USB message */ static void ucan_write_bulk_callback(struct urb *urb) { unsigned long flags; struct ucan_priv *up; struct ucan_urb_context *context = urb->context; /* get the urb context */ if (WARN_ON_ONCE(!context)) return; /* free up our allocated buffer */ usb_free_coherent(urb->dev, sizeof(struct ucan_message_out), urb->transfer_buffer, urb->transfer_dma); up = context->up; if (WARN_ON_ONCE(!up)) return; /* sanity check */ if (!netif_device_present(up->netdev)) return; /* transmission failed (USB - the device will not send a TX complete) */ if (urb->status) { netdev_warn(up->netdev, "failed to transmit USB message to device: %d\n", urb->status); /* update counters an cleanup */ spin_lock_irqsave(&up->echo_skb_lock, flags); can_free_echo_skb(up->netdev, context - up->context_array, NULL); spin_unlock_irqrestore(&up->echo_skb_lock, flags); up->netdev->stats.tx_dropped++; /* release context and restart the queue if necessary */ if (!ucan_release_context(up, context)) netdev_err(up->netdev, "urb failed, failed to release context\n"); } } static void ucan_cleanup_rx_urbs(struct ucan_priv *up, struct urb **urbs) { int i; for (i = 0; i < UCAN_MAX_RX_URBS; i++) { if (urbs[i]) { usb_unanchor_urb(urbs[i]); usb_free_coherent(up->udev, up->in_ep_size, urbs[i]->transfer_buffer, urbs[i]->transfer_dma); usb_free_urb(urbs[i]); } } memset(urbs, 0, sizeof(*urbs) * UCAN_MAX_RX_URBS); } static int ucan_prepare_and_anchor_rx_urbs(struct ucan_priv *up, struct urb **urbs) { int i; memset(urbs, 0, sizeof(*urbs) * UCAN_MAX_RX_URBS); for (i = 0; i < UCAN_MAX_RX_URBS; i++) { void *buf; urbs[i] = usb_alloc_urb(0, GFP_KERNEL); if (!urbs[i]) goto err; buf = usb_alloc_coherent(up->udev, up->in_ep_size, GFP_KERNEL, &urbs[i]->transfer_dma); if (!buf) { /* cleanup this urb */ usb_free_urb(urbs[i]); urbs[i] = NULL; goto err; } usb_fill_bulk_urb(urbs[i], up->udev, usb_rcvbulkpipe(up->udev, up->in_ep_addr), buf, up->in_ep_size, ucan_read_bulk_callback, up); urbs[i]->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; usb_anchor_urb(urbs[i], &up->rx_urbs); } return 0; err: /* cleanup other unsubmitted urbs */ ucan_cleanup_rx_urbs(up, urbs); return -ENOMEM; } /* Submits rx urbs with the semantic: Either submit all, or cleanup * everything. I case of errors submitted urbs are killed and all urbs in * the array are freed. I case of no errors every entry in the urb * array is set to NULL. */ static int ucan_submit_rx_urbs(struct ucan_priv *up, struct urb **urbs) { int i, ret; /* Iterate over all urbs to submit. On success remove the urb * from the list. */ for (i = 0; i < UCAN_MAX_RX_URBS; i++) { ret = usb_submit_urb(urbs[i], GFP_KERNEL); if (ret) { netdev_err(up->netdev, "could not submit urb; code: %d\n", ret); goto err; } /* Anchor URB and drop reference, USB core will take * care of freeing it */ usb_free_urb(urbs[i]); urbs[i] = NULL; } return 0; err: /* Cleanup unsubmitted urbs */ ucan_cleanup_rx_urbs(up, urbs); /* Kill urbs that are already submitted */ usb_kill_anchored_urbs(&up->rx_urbs); return ret; } /* Open the network device */ static int ucan_open(struct net_device *netdev) { int ret, ret_cleanup; u16 ctrlmode; struct urb *urbs[UCAN_MAX_RX_URBS]; struct ucan_priv *up = netdev_priv(netdev); ret = ucan_alloc_context_array(up); if (ret) return ret; /* Allocate and prepare IN URBS - allocated and anchored * urbs are stored in urbs[] for clean */ ret = ucan_prepare_and_anchor_rx_urbs(up, urbs); if (ret) goto err_contexts; /* Check the control mode */ ctrlmode = 0; if (up->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) ctrlmode |= UCAN_MODE_LOOPBACK; if (up->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) ctrlmode |= UCAN_MODE_SILENT; if (up->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) ctrlmode |= UCAN_MODE_3_SAMPLES; if (up->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) ctrlmode |= UCAN_MODE_ONE_SHOT; /* Enable this in any case - filtering is down within the * receive path */ ctrlmode |= UCAN_MODE_BERR_REPORT; up->ctl_msg_buffer->cmd_start.mode = cpu_to_le16(ctrlmode); /* Driver is ready to receive data - start the USB device */ ret = ucan_ctrl_command_out(up, UCAN_COMMAND_START, 0, 2); if (ret < 0) { netdev_err(up->netdev, "could not start device, code: %d\n", ret); goto err_reset; } /* Call CAN layer open */ ret = open_candev(netdev); if (ret) goto err_stop; /* Driver is ready to receive data. Submit RX URBS */ ret = ucan_submit_rx_urbs(up, urbs); if (ret) goto err_stop; up->can.state = CAN_STATE_ERROR_ACTIVE; /* Start the network queue */ netif_start_queue(netdev); return 0; err_stop: /* The device have started already stop it */ ret_cleanup = ucan_ctrl_command_out(up, UCAN_COMMAND_STOP, 0, 0); if (ret_cleanup < 0) netdev_err(up->netdev, "could not stop device, code: %d\n", ret_cleanup); err_reset: /* The device might have received data, reset it for * consistent state */ ret_cleanup = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0); if (ret_cleanup < 0) netdev_err(up->netdev, "could not reset device, code: %d\n", ret_cleanup); /* clean up unsubmitted urbs */ ucan_cleanup_rx_urbs(up, urbs); err_contexts: ucan_release_context_array(up); return ret; } static struct urb *ucan_prepare_tx_urb(struct ucan_priv *up, struct ucan_urb_context *context, struct can_frame *cf, u8 echo_index) { int mlen; struct urb *urb; struct ucan_message_out *m; /* create a URB, and a buffer for it, and copy the data to the URB */ urb = usb_alloc_urb(0, GFP_ATOMIC); if (!urb) { netdev_err(up->netdev, "no memory left for URBs\n"); return NULL; } m = usb_alloc_coherent(up->udev, sizeof(struct ucan_message_out), GFP_ATOMIC, &urb->transfer_dma); if (!m) { netdev_err(up->netdev, "no memory left for USB buffer\n"); usb_free_urb(urb); return NULL; } /* build the USB message */ m->type = UCAN_OUT_TX; m->msg.can_msg.id = cpu_to_le32(cf->can_id); if (cf->can_id & CAN_RTR_FLAG) { mlen = UCAN_OUT_HDR_SIZE + offsetof(struct ucan_can_msg, dlc) + sizeof(m->msg.can_msg.dlc); m->msg.can_msg.dlc = cf->len; } else { mlen = UCAN_OUT_HDR_SIZE + sizeof(m->msg.can_msg.id) + cf->len; memcpy(m->msg.can_msg.data, cf->data, cf->len); } m->len = cpu_to_le16(mlen); m->subtype = echo_index; /* build the urb */ usb_fill_bulk_urb(urb, up->udev, usb_sndbulkpipe(up->udev, up->out_ep_addr), m, mlen, ucan_write_bulk_callback, context); urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; return urb; } static void ucan_clean_up_tx_urb(struct ucan_priv *up, struct urb *urb) { usb_free_coherent(up->udev, sizeof(struct ucan_message_out), urb->transfer_buffer, urb->transfer_dma); usb_free_urb(urb); } /* callback when Linux needs to send a can frame */ static netdev_tx_t ucan_start_xmit(struct sk_buff *skb, struct net_device *netdev) { unsigned long flags; int ret; u8 echo_index; struct urb *urb; struct ucan_urb_context *context; struct ucan_priv *up = netdev_priv(netdev); struct can_frame *cf = (struct can_frame *)skb->data; /* check skb */ if (can_dev_dropped_skb(netdev, skb)) return NETDEV_TX_OK; /* allocate a context and slow down tx path, if fifo state is low */ context = ucan_alloc_context(up); echo_index = context - up->context_array; if (WARN_ON_ONCE(!context)) return NETDEV_TX_BUSY; /* prepare urb for transmission */ urb = ucan_prepare_tx_urb(up, context, cf, echo_index); if (!urb) goto drop; /* put the skb on can loopback stack */ spin_lock_irqsave(&up->echo_skb_lock, flags); can_put_echo_skb(skb, up->netdev, echo_index, 0); spin_unlock_irqrestore(&up->echo_skb_lock, flags); /* transmit it */ usb_anchor_urb(urb, &up->tx_urbs); ret = usb_submit_urb(urb, GFP_ATOMIC); /* cleanup urb */ if (ret) { /* on error, clean up */ usb_unanchor_urb(urb); ucan_clean_up_tx_urb(up, urb); if (!ucan_release_context(up, context)) netdev_err(up->netdev, "xmit err: failed to release context\n"); /* remove the skb from the echo stack - this also * frees the skb */ spin_lock_irqsave(&up->echo_skb_lock, flags); can_free_echo_skb(up->netdev, echo_index, NULL); spin_unlock_irqrestore(&up->echo_skb_lock, flags); if (ret == -ENODEV) { netif_device_detach(up->netdev); } else { netdev_warn(up->netdev, "xmit err: failed to submit urb %d\n", ret); up->netdev->stats.tx_dropped++; } return NETDEV_TX_OK; } netif_trans_update(netdev); /* release ref, as we do not need the urb anymore */ usb_free_urb(urb); return NETDEV_TX_OK; drop: if (!ucan_release_context(up, context)) netdev_err(up->netdev, "xmit drop: failed to release context\n"); dev_kfree_skb(skb); up->netdev->stats.tx_dropped++; return NETDEV_TX_OK; } /* Device goes down * * Clean up used resources */ static int ucan_close(struct net_device *netdev) { int ret; struct ucan_priv *up = netdev_priv(netdev); up->can.state = CAN_STATE_STOPPED; /* stop sending data */ usb_kill_anchored_urbs(&up->tx_urbs); /* stop receiving data */ usb_kill_anchored_urbs(&up->rx_urbs); /* stop and reset can device */ ret = ucan_ctrl_command_out(up, UCAN_COMMAND_STOP, 0, 0); if (ret < 0) netdev_err(up->netdev, "could not stop device, code: %d\n", ret); ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0); if (ret < 0) netdev_err(up->netdev, "could not reset device, code: %d\n", ret); netif_stop_queue(netdev); ucan_release_context_array(up); close_candev(up->netdev); return 0; } /* CAN driver callbacks */ static const struct net_device_ops ucan_netdev_ops = { .ndo_open = ucan_open, .ndo_stop = ucan_close, .ndo_start_xmit = ucan_start_xmit, .ndo_change_mtu = can_change_mtu, }; static const struct ethtool_ops ucan_ethtool_ops = { .get_ts_info = ethtool_op_get_ts_info, }; /* Request to set bittiming * * This function generates an USB set bittiming message and transmits * it to the device */ static int ucan_set_bittiming(struct net_device *netdev) { int ret; struct ucan_priv *up = netdev_priv(netdev); struct ucan_ctl_cmd_set_bittiming *cmd_set_bittiming; cmd_set_bittiming = &up->ctl_msg_buffer->cmd_set_bittiming; cmd_set_bittiming->tq = cpu_to_le32(up->can.bittiming.tq); cmd_set_bittiming->brp = cpu_to_le16(up->can.bittiming.brp); cmd_set_bittiming->sample_point = cpu_to_le16(up->can.bittiming.sample_point); cmd_set_bittiming->prop_seg = up->can.bittiming.prop_seg; cmd_set_bittiming->phase_seg1 = up->can.bittiming.phase_seg1; cmd_set_bittiming->phase_seg2 = up->can.bittiming.phase_seg2; cmd_set_bittiming->sjw = up->can.bittiming.sjw; ret = ucan_ctrl_command_out(up, UCAN_COMMAND_SET_BITTIMING, 0, sizeof(*cmd_set_bittiming)); return (ret < 0) ? ret : 0; } /* Restart the device to get it out of BUS-OFF state. * Called when the user runs "ip link set can1 type can restart". */ static int ucan_set_mode(struct net_device *netdev, enum can_mode mode) { int ret; unsigned long flags; struct ucan_priv *up = netdev_priv(netdev); switch (mode) { case CAN_MODE_START: netdev_dbg(up->netdev, "restarting device\n"); ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESTART, 0, 0); up->can.state = CAN_STATE_ERROR_ACTIVE; /* check if queue can be restarted, * up->available_tx_urbs must be protected by the * lock */ spin_lock_irqsave(&up->context_lock, flags); if (up->available_tx_urbs > 0) netif_wake_queue(up->netdev); spin_unlock_irqrestore(&up->context_lock, flags); return ret; default: return -EOPNOTSUPP; } } /* Probe the device, reset it and gather general device information */ static int ucan_probe(struct usb_interface *intf, const struct usb_device_id *id) { int ret; int i; u32 protocol_version; struct usb_device *udev; struct net_device *netdev; struct usb_host_interface *iface_desc; struct ucan_priv *up; struct usb_endpoint_descriptor *ep; u16 in_ep_size; u16 out_ep_size; u8 in_ep_addr; u8 out_ep_addr; union ucan_ctl_payload *ctl_msg_buffer; char firmware_str[sizeof(union ucan_ctl_payload) + 1]; udev = interface_to_usbdev(intf); /* Stage 1 - Interface Parsing * --------------------------- * * Identifie the device USB interface descriptor and its * endpoints. Probing is aborted on errors. */ /* check if the interface is sane */ iface_desc = intf->cur_altsetting; if (!iface_desc) return -ENODEV; dev_info(&udev->dev, "%s: probing device on interface #%d\n", UCAN_DRIVER_NAME, iface_desc->desc.bInterfaceNumber); /* interface sanity check */ if (iface_desc->desc.bNumEndpoints != 2) { dev_err(&udev->dev, "%s: invalid EP count (%d)", UCAN_DRIVER_NAME, iface_desc->desc.bNumEndpoints); goto err_firmware_needs_update; } /* check interface endpoints */ in_ep_addr = 0; out_ep_addr = 0; in_ep_size = 0; out_ep_size = 0; for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) { ep = &iface_desc->endpoint[i].desc; if (((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != 0) && ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* In Endpoint */ in_ep_addr = ep->bEndpointAddress; in_ep_addr &= USB_ENDPOINT_NUMBER_MASK; in_ep_size = le16_to_cpu(ep->wMaxPacketSize); } else if (((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == 0) && ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* Out Endpoint */ out_ep_addr = ep->bEndpointAddress; out_ep_addr &= USB_ENDPOINT_NUMBER_MASK; out_ep_size = le16_to_cpu(ep->wMaxPacketSize); } } /* check if interface is sane */ if (!in_ep_addr || !out_ep_addr) { dev_err(&udev->dev, "%s: invalid endpoint configuration\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } if (in_ep_size < sizeof(struct ucan_message_in)) { dev_err(&udev->dev, "%s: invalid in_ep MaxPacketSize\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } if (out_ep_size < sizeof(struct ucan_message_out)) { dev_err(&udev->dev, "%s: invalid out_ep MaxPacketSize\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } /* Stage 2 - Device Identification * ------------------------------- * * The device interface seems to be a ucan device. Do further * compatibility checks. On error probing is aborted, on * success this stage leaves the ctl_msg_buffer with the * reported contents of a GET_INFO command (supported * bittimings, tx_fifo depth). This information is used in * Stage 3 for the final driver initialisation. */ /* Prepare Memory for control transfers */ ctl_msg_buffer = devm_kzalloc(&udev->dev, sizeof(union ucan_ctl_payload), GFP_KERNEL); if (!ctl_msg_buffer) { dev_err(&udev->dev, "%s: failed to allocate control pipe memory\n", UCAN_DRIVER_NAME); return -ENOMEM; } /* get protocol version * * note: ucan_ctrl_command_* wrappers cannot be used yet * because `up` is initialised in Stage 3 */ ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), UCAN_COMMAND_GET, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE, UCAN_COMMAND_GET_PROTOCOL_VERSION, iface_desc->desc.bInterfaceNumber, ctl_msg_buffer, sizeof(union ucan_ctl_payload), UCAN_USB_CTL_PIPE_TIMEOUT); /* older firmware version do not support this command - those * are not supported by this drive */ if (ret != 4) { dev_err(&udev->dev, "%s: could not read protocol version, ret=%d\n", UCAN_DRIVER_NAME, ret); if (ret >= 0) ret = -EINVAL; goto err_firmware_needs_update; } /* this driver currently supports protocol version 3 only */ protocol_version = le32_to_cpu(ctl_msg_buffer->cmd_get_protocol_version.version); if (protocol_version < UCAN_PROTOCOL_VERSION_MIN || protocol_version > UCAN_PROTOCOL_VERSION_MAX) { dev_err(&udev->dev, "%s: device protocol version %d is not supported\n", UCAN_DRIVER_NAME, protocol_version); goto err_firmware_needs_update; } /* request the device information and store it in ctl_msg_buffer * * note: ucan_ctrl_command_* wrappers cannot be used yet * because `up` is initialised in Stage 3 */ ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), UCAN_COMMAND_GET, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE, UCAN_COMMAND_GET_INFO, iface_desc->desc.bInterfaceNumber, ctl_msg_buffer, sizeof(ctl_msg_buffer->cmd_get_device_info), UCAN_USB_CTL_PIPE_TIMEOUT); if (ret < 0) { dev_err(&udev->dev, "%s: failed to retrieve device info\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } if (ret < sizeof(ctl_msg_buffer->cmd_get_device_info)) { dev_err(&udev->dev, "%s: device reported invalid device info\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } if (ctl_msg_buffer->cmd_get_device_info.tx_fifo == 0) { dev_err(&udev->dev, "%s: device reported invalid tx-fifo size\n", UCAN_DRIVER_NAME); goto err_firmware_needs_update; } /* Stage 3 - Driver Initialisation * ------------------------------- * * Register device to Linux, prepare private structures and * reset the device. */ /* allocate driver resources */ netdev = alloc_candev(sizeof(struct ucan_priv), ctl_msg_buffer->cmd_get_device_info.tx_fifo); if (!netdev) { dev_err(&udev->dev, "%s: cannot allocate candev\n", UCAN_DRIVER_NAME); return -ENOMEM; } up = netdev_priv(netdev); /* initialize data */ up->udev = udev; up->netdev = netdev; up->intf_index = iface_desc->desc.bInterfaceNumber; up->in_ep_addr = in_ep_addr; up->out_ep_addr = out_ep_addr; up->in_ep_size = in_ep_size; up->ctl_msg_buffer = ctl_msg_buffer; up->context_array = NULL; up->available_tx_urbs = 0; up->can.state = CAN_STATE_STOPPED; up->can.bittiming_const = &up->device_info.bittiming_const; up->can.do_set_bittiming = ucan_set_bittiming; up->can.do_set_mode = &ucan_set_mode; spin_lock_init(&up->context_lock); spin_lock_init(&up->echo_skb_lock); netdev->netdev_ops = &ucan_netdev_ops; netdev->ethtool_ops = &ucan_ethtool_ops; usb_set_intfdata(intf, up); SET_NETDEV_DEV(netdev, &intf->dev); /* parse device information * the data retrieved in Stage 2 is still available in * up->ctl_msg_buffer */ ucan_parse_device_info(up, &ctl_msg_buffer->cmd_get_device_info); /* just print some device information - if available */ ret = ucan_device_request_in(up, UCAN_DEVICE_GET_FW_STRING, 0, sizeof(union ucan_ctl_payload)); if (ret > 0) { /* copy string while ensuring zero termination */ strscpy(firmware_str, up->ctl_msg_buffer->raw, sizeof(union ucan_ctl_payload) + 1); } else { strcpy(firmware_str, "unknown"); } /* device is compatible, reset it */ ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0); if (ret < 0) goto err_free_candev; init_usb_anchor(&up->rx_urbs); init_usb_anchor(&up->tx_urbs); up->can.state = CAN_STATE_STOPPED; /* register the device */ ret = register_candev(netdev); if (ret) goto err_free_candev; /* initialisation complete, log device info */ netdev_info(up->netdev, "registered device\n"); netdev_info(up->netdev, "firmware string: %s\n", firmware_str); /* success */ return 0; err_free_candev: free_candev(netdev); return ret; err_firmware_needs_update: dev_err(&udev->dev, "%s: probe failed; try to update the device firmware\n", UCAN_DRIVER_NAME); return -ENODEV; } /* disconnect the device */ static void ucan_disconnect(struct usb_interface *intf) { struct ucan_priv *up = usb_get_intfdata(intf); usb_set_intfdata(intf, NULL); if (up) { unregister_candev(up->netdev); free_candev(up->netdev); } } static struct usb_device_id ucan_table[] = { /* Mule (soldered onto compute modules) */ {USB_DEVICE_INTERFACE_NUMBER(0x2294, 0x425a, 0)}, /* Seal (standalone USB stick) */ {USB_DEVICE_INTERFACE_NUMBER(0x2294, 0x425b, 0)}, {} /* Terminating entry */ }; MODULE_DEVICE_TABLE(usb, ucan_table); /* driver callbacks */ static struct usb_driver ucan_driver = { .name = UCAN_DRIVER_NAME, .probe = ucan_probe, .disconnect = ucan_disconnect, .id_table = ucan_table, }; module_usb_driver(ucan_driver); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Martin Elshuber <martin.elshuber@theobroma-systems.com>"); MODULE_AUTHOR("Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>"); MODULE_DESCRIPTION("Driver for Theobroma Systems UCAN devices");
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