Hi Sebastian,
Sebastian Haas wrote:
> This patch adds support for one channel CAN/USB interace CPC-USB/ARM7 from
> EMS Dr. Thomas Wuensche (http://www.ems-wuensche.com).
>
> Signed-off-by: Sebastian Haas <[email protected]>
The driver is almost OK from the Socket-CAN point of view. Just some
*final* nitpicking:
[snip]
> +static void ems_usb_read_interrupt_callback(struct urb *urb)
> +{
> + struct ems_usb *dev = urb->context;
> + struct net_device *netdev;
> + int err;
> +
> + netdev = dev->netdev;
Could be done in the declaration part above.
> + 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 = dev_alloc_skb(sizeof(struct can_frame));
Please use netdev_alloc_skb() ...
> + if (skb == NULL)
> + return;
> +
> + skb->dev = dev->netdev;
... making the line above obsolete.
> + 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);
> +
> + dev->netdev->last_rx = jiffies;
> + 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 = dev_alloc_skb(sizeof(struct can_frame));
> + if (skb == NULL)
> + return;
> +
> + skb->dev = dev->netdev;
Ditto.
[snip]
> +static int 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 & 0x1FFFFFFFU;
Please use CAN_ERR_MASK instead (even if the name is somehow
misleading). See http://lxr.linux.no/#linux+v2.6.31/include/linux/can.h#L31.
[snip]
> +}
> +
> +
Remove one empty line, please.
> +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;
> +
> + 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.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 */
> +
> + /*
> + * The device actually uses a 16MHz clock to generate the CAN clock
> + * but it expects SJA1000 bit settings based on 8MHz (is internally
> + * converted).
> + */
Should go up to the macro definition.
> + dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
> +
> + 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");
> + free_candev(netdev);
Please use goto's for cleanup to avoid code duplication.
> + return -ENOMEM;
> + }
> +
> + 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");
> + free_candev(netdev);
> + usb_free_urb(dev->intr_urb);
> + return -ENOMEM;
Ditto.
> + }
> +
> + 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");
> + free_candev(netdev);
> + usb_free_urb(dev->intr_urb);
> + kfree(dev->intr_in_buffer);
> + return -ENOMEM;
Ditto.
> + }
> +
> + 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);
> + free_candev(netdev);
> + usb_free_urb(dev->intr_urb);
> + return err;
Ditto. Also kfree(dev->intr_in_buffer) seems to be missing.
Please add a version number to the next patch, e.g. [PATCH v3 ...].
It would also be nice, if some USB guru's could have a look as well.
Thanks,
Wolfgang.
_______________________________________________
Socketcan-core mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/socketcan-core
