Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Marc Kleine-Budde]

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On 12/04/2012 11:43 PM, Bernd Krumboeck wrote:
> Add device driver for USB2CAN interface from "8 devices"
> (http://www.8devices.com).
> 
> Signed-off-by: Bernd Krumboeck <krumboeck-Hi41barv6paIERSsAYjmKA@public.gmane.org>

Please use git send-email.

A changelog would be nice, in the form of:

changes since v4:
- done this, deleted that

If you post v5, changes since v4 are sufficient.

> ---
>  drivers/net/can/usb/Kconfig    |    6 +
>  drivers/net/can/usb/Makefile   |    1 +
>  drivers/net/can/usb/usb_8dev.c | 1089
> ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1096 insertions(+)
>  create mode 100644 drivers/net/can/usb/usb_8dev.c
> 
> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> index a4e4bee..2162233 100644
> --- a/drivers/net/can/usb/Kconfig
> +++ b/drivers/net/can/usb/Kconfig
> @@ -48,4 +48,10 @@ config CAN_PEAK_USB
>        This driver supports the PCAN-USB and PCAN-USB Pro adapters
>        from PEAK-System Technik (http://www.peak-system.com).
> 
> +config CAN_8DEV_USB
> +    tristate "8 devices USB2CAN interface"
> +    ---help---
> +      This driver supports the USB2CAN interface
> +      from 8 devices (http://www.8devices.com).
> +
>  endmenu
> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> index 80a2ee4..becef46 100644
> --- a/drivers/net/can/usb/Makefile
> +++ b/drivers/net/can/usb/Makefile
> @@ -6,5 +6,6 @@ obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
>  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
>  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
> +obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
> 
>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/usb/usb_8dev.c
> b/drivers/net/can/usb/usb_8dev.c
> new file mode 100644
> index 0000000..b3a7eee
> --- /dev/null
> +++ b/drivers/net/can/usb/usb_8dev.c
> @@ -0,0 +1,1089 @@
> +/*
> + * CAN driver for "8 devices" USB2CAN converter
> + *
> + * Copyright (C) 2012 Bernd Krumboeck (krumboeck-Hi41barv6paIERSsAYjmKA@public.gmane.org)
> + *
> + * 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.

you can remove the address here.

> + *
> + * This driver is inspired by the 3.2.0 version of
> drivers/net/can/usb/ems_usb.c
> + * and drivers/net/can/usb/esd_usb2.c
> + *
> + * Many thanks to Gerhard Bertelsmann (info-La43T0Mi4bH5xCKuJOYmCvaTkwRoYoCU@public.gmane.org)
> + * for testing and fixing this driver. Also many thanks to "8 devices",
> + * who were very cooperative and answered my questions.
> + */

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Marc Kleine-Budde]

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On 12/04/2012 11:11 PM, Marc Kleine-Budde wrote:
> On 12/04/2012 11:43 PM, Bernd Krumboeck wrote:
                ^^^^^^^^

btw: your clock is wrong by about 1h :)

Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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[PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Bernd Krumboeck]

Add device driver for USB2CAN interface from "8 devices" (http://www.8devices.com).

Signed-off-by: Bernd Krumboeck <krumboeck@universalnet.at>
---
  drivers/net/can/usb/Kconfig    |    6 +
  drivers/net/can/usb/Makefile   |    1 +
  drivers/net/can/usb/usb_8dev.c | 1089 ++++++++++++++++++++++++++++++++++++++++
  3 files changed, 1096 insertions(+)
  create mode 100644 drivers/net/can/usb/usb_8dev.c

diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index a4e4bee..2162233 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -48,4 +48,10 @@ config CAN_PEAK_USB
  	  This driver supports the PCAN-USB and PCAN-USB Pro adapters
  	  from PEAK-System Technik (http://www.peak-system.com).

+config CAN_8DEV_USB
+	tristate "8 devices USB2CAN interface"
+	---help---
+	  This driver supports the USB2CAN interface
+	  from 8 devices (http://www.8devices.com).
+
  endmenu
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index 80a2ee4..becef46 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -6,5 +6,6 @@ obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
+obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o

  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
new file mode 100644
index 0000000..b3a7eee
--- /dev/null
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -0,0 +1,1089 @@
+/*
+ * CAN driver for "8 devices" USB2CAN converter
+ *
+ * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at)
+ *
+ * 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.
+ *
+ * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
+ * and drivers/net/can/usb/esd_usb2.c
+ *
+ * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de)
+ * for testing and fixing this driver. Also many thanks to "8 devices",
+ * who were very cooperative and answered my questions.
+ */
+
+#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>
+
+/* driver constants */
+#define MAX_RX_URBS			10
+#define MAX_TX_URBS			10
+#define RX_BUFFER_SIZE			64
+
+/* vendor and product id */
+#define USB_8DEV_VENDOR_ID		0x0483
+#define USB_8DEV_PRODUCT_ID		0x1234
+
+/* endpoints */
+enum usb_8dev_endpoint {
+	USB_8DEV_ENDP_DATA_RX = 1,
+	USB_8DEV_ENDP_DATA_TX,
+	USB_8DEV_ENDP_CMD_RX,
+	USB_8DEV_ENDP_CMD_TX
+};
+
+/* bittiming constants */
+#define USB_8DEV_ABP_CLOCK		32000000
+#define USB_8DEV_BAUD_MANUAL		0x09
+#define USB_8DEV_TSEG1_MIN		1
+#define USB_8DEV_TSEG1_MAX		16
+#define USB_8DEV_TSEG2_MIN		1
+#define USB_8DEV_TSEG2_MAX		8
+#define USB_8DEV_SJW_MAX		4
+#define USB_8DEV_BRP_MIN		1
+#define USB_8DEV_BRP_MAX		1024
+#define USB_8DEV_BRP_INC		1
+
+/* setup flags */
+#define USB_8DEV_SILENT			0x01
+#define USB_8DEV_LOOPBACK		0x02
+#define USB_8DEV_DISABLE_AUTO_RESTRANS	0x04
+#define USB_8DEV_STATUS_FRAME		0x08
+
+/* commands */
+enum usb_8dev_cmd {
+	USB_8DEV_RESET = 1,
+	USB_8DEV_OPEN,
+	USB_8DEV_CLOSE,
+	USB_8DEV_SET_SPEED,
+	USB_8DEV_SET_MASK_FILTER,
+	USB_8DEV_GET_STATUS,
+	USB_8DEV_GET_STATISTICS,
+	USB_8DEV_GET_SERIAL,
+	USB_8DEV_GET_SOFTW_VER,
+	USB_8DEV_GET_HARDW_VER,
+	USB_8DEV_RESET_TIMESTAMP,
+	USB_8DEV_GET_SOFTW_HARDW_VER
+};
+
+#define USB_8DEV_CMD_START		0x11
+#define USB_8DEV_CMD_END		0x22
+
+#define USB_8DEV_CMD_SUCCESS		0
+#define USB_8DEV_CMD_ERROR		255
+
+#define USB_8DEV_CMD_TIMEOUT		1000
+
+/* frames */
+#define USB_8DEV_DATA_START		0x55
+#define USB_8DEV_DATA_END		0xAA
+
+#define USB_8DEV_TYPE_CAN_FRAME		0
+#define USB_8DEV_TYPE_ERROR_FRAME	3
+
+#define USB_8DEV_EXTID			0x01
+#define USB_8DEV_RTR			0x02
+#define USB_8DEV_ERR_FLAG		0x04
+
+/* status */
+#define USB_8DEV_STATUSMSG_OK		0x00  /* Normal condition. */
+#define USB_8DEV_STATUSMSG_OVERRUN	0x01  /* Overrun occured when sending */
+#define USB_8DEV_STATUSMSG_BUSLIGHT	0x02  /* Error counter has reached 96 */
+#define USB_8DEV_STATUSMSG_BUSHEAVY	0x03  /* Error count. has reached 128 */
+#define USB_8DEV_STATUSMSG_BUSOFF	0x04  /* Device is in BUSOFF */
+#define USB_8DEV_STATUSMSG_STUFF	0x20  /* Stuff Error */
+#define USB_8DEV_STATUSMSG_FORM		0x21  /* Form Error */
+#define USB_8DEV_STATUSMSG_ACK		0x23  /* Ack Error */
+#define USB_8DEV_STATUSMSG_BIT0		0x24  /* Bit1 Error */
+#define USB_8DEV_STATUSMSG_BIT1		0x25  /* Bit0 Error */
+#define USB_8DEV_STATUSMSG_CRC		0x26  /* CRC Error */
+
+#define USB_8DEV_RP_MASK		0x7F  /* Mask for Receive Error Bit */
+
+
+/* table of devices that work with this driver */
+static const struct usb_device_id usb_8dev_table[] = {
+	{ USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
+	{ }					/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_8dev_table);
+
+struct usb_8dev_tx_urb_context {
+	struct usb_8dev *dev;
+
+	u32 echo_index;
+	u8 dlc;
+};
+
+/* Structure to hold all of our device specific stuff */
+struct usb_8dev {
+	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 usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
+
+	struct usb_anchor rx_submitted;
+
+	struct can_berr_counter bec;
+
+	u8 *cmd_msg_buffer;
+
+	unsigned int free_slots; /* remember number of available slots */
+
+	struct mutex usb_8dev_cmd_lock;
+
+};
+
+/* tx frame */
+struct __packed usb_8dev_tx_msg {
+	u8 begin;
+	u8 flags;	/* RTR and EXT_ID flag */
+	__be32 id;	/* upper 3 bits not used */
+	u8 dlc;		/* data length code 0-8 bytes */
+	u8 data[8];	/* 64-bit data */
+	u8 end;
+};
+
+/* rx frame */
+struct __packed usb_8dev_rx_msg {
+	u8 begin;
+	u8 type;		/* frame type */
+	u8 flags;		/* RTR and EXT_ID flag */
+	__be32 id;		/* upper 3 bits not used */
+	u8 dlc;			/* data length code 0-8 bytes */
+	u8 data[8];		/* 64-bit data */
+	__be32 timestamp;	/* 32-bit timestamp */
+	u8 end;
+};
+
+/* command frame */
+struct __packed usb_8dev_cmd_msg {
+	u8 begin;
+	u8 channel;	/* unkown - always 0 */
+	u8 command;	/* command to execute */
+	u8 opt1;	/* optional parameter / return value */
+	u8 opt2;	/* optional parameter 2 */
+	u8 data[10];	/* optional parameter and data */
+	u8 end;
+};
+
+static struct usb_driver usb_8dev_driver;
+
+static int usb_8dev_send_cmd_msg(struct usb_8dev *dev, u8 *msg, int size)
+{
+	int actual_length;
+
+	return usb_bulk_msg(dev->udev,
+			    usb_sndbulkpipe(dev->udev, USB_8DEV_ENDP_CMD_TX),
+			    msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
+}
+
+static int usb_8dev_wait_cmd_msg(struct usb_8dev *dev, u8 *msg, int size,
+				int *actual_length)
+{
+	return usb_bulk_msg(dev->udev,
+			    usb_rcvbulkpipe(dev->udev, USB_8DEV_ENDP_CMD_RX),
+			    msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
+}
+
+/*
+ * Send command to device and receive result.
+ * Command was successful when opt1 = 0.
+ */
+static int usb_8dev_send_cmd(struct usb_8dev *dev, struct usb_8dev_cmd_msg *out,
+			    struct usb_8dev_cmd_msg *in)
+{
+	int err;
+	int num_bytes_read;
+	struct net_device *netdev;
+
+	netdev = dev->netdev;
+
+	out->begin = USB_8DEV_CMD_START;
+	out->end = USB_8DEV_CMD_END;
+
+	mutex_lock(&dev->usb_8dev_cmd_lock);
+
+	memcpy(dev->cmd_msg_buffer, out,
+		sizeof(struct usb_8dev_cmd_msg));
+
+	err = usb_8dev_send_cmd_msg(dev, dev->cmd_msg_buffer,
+				    sizeof(struct usb_8dev_cmd_msg));
+	if (err < 0) {
+		netdev_err(netdev, "sending command message failed\n");
+		return err;
+	}
+
+	err = usb_8dev_wait_cmd_msg(dev, dev->cmd_msg_buffer,
+				    sizeof(struct usb_8dev_cmd_msg),
+				    &num_bytes_read);
+	if (err < 0) {
+		netdev_err(netdev, "no command message answer\n");
+		return err;
+	}
+
+	memcpy(in, dev->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
+
+	mutex_unlock(&dev->usb_8dev_cmd_lock);
+
+	if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
+			num_bytes_read != 16 || in->opt1 != 0)
+		return -EPROTO;
+
+	return 0;
+}
+
+/* Send open command to device */
+static int usb_8dev_cmd_open(struct usb_8dev *dev)
+{
+	struct can_bittiming *bt = &dev->can.bittiming;
+	struct usb_8dev_cmd_msg outmsg;
+	struct usb_8dev_cmd_msg inmsg;
+	u32 flags = 0;
+	u32 beflags;
+	u16 bebrp;
+	u32 ctrlmode = dev->can.ctrlmode;
+
+	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		flags |= USB_8DEV_LOOPBACK;
+	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		flags |= USB_8DEV_SILENT;
+	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+		flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
+
+	flags |= USB_8DEV_STATUS_FRAME;
+
+	memset(&outmsg, 0, sizeof(struct usb_8dev_cmd_msg));
+	outmsg.command = USB_8DEV_OPEN;
+	outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
+	outmsg.data[0] = (bt->prop_seg + bt->phase_seg1);
+	outmsg.data[1] = bt->phase_seg2;
+	outmsg.data[2] = bt->sjw;
+
+	/* BRP */
+	bebrp = cpu_to_be16((u16) bt->brp);
+	memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
+
+	/* flags */
+	beflags = cpu_to_be32(flags);
+	memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
+
+	return usb_8dev_send_cmd(dev, &outmsg, &inmsg);
+}
+
+/* Send close command to device */
+static int usb_8dev_cmd_close(struct usb_8dev *dev)
+{
+	struct usb_8dev_cmd_msg inmsg;
+	struct usb_8dev_cmd_msg outmsg = {
+		.channel = 0,
+		.command = USB_8DEV_CLOSE,
+		.opt1 = 0,
+		.opt2 = 0
+		};
+
+	return usb_8dev_send_cmd(dev, &outmsg, &inmsg);
+}
+
+/* Get firmware and hardware version */
+static int usb_8dev_cmd_version(struct usb_8dev *dev, u32 *res)
+{
+	struct usb_8dev_cmd_msg	inmsg;
+	struct usb_8dev_cmd_msg	outmsg = {
+		.channel = 0,
+		.command = USB_8DEV_GET_SOFTW_HARDW_VER,
+		.opt1 = 0,
+		.opt2 = 0
+		};
+
+	int err = usb_8dev_send_cmd(dev, &outmsg, &inmsg);
+	if (err)
+		return err;
+
+	*res = be32_to_cpu(*(u32 *)inmsg.data);
+
+	return err;
+}
+
+/* Get firmware version */
+static ssize_t show_firmware(struct device *d, struct device_attribute *attr,
+			     char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(d);
+	struct usb_8dev *dev = usb_get_intfdata(intf);
+	u16 result;
+	struct usb_8dev_cmd_msg inmsg;
+	struct usb_8dev_cmd_msg outmsg = {
+		.channel = 0,
+		.command = USB_8DEV_GET_SOFTW_VER,
+		.opt1 = 0,
+		.opt2 = 0
+		};
+
+	int err = usb_8dev_send_cmd(dev, &outmsg, &inmsg);
+	if (err)
+		return -EIO;
+
+	result = be16_to_cpu(*(u16 *)inmsg.data);
+
+	return sprintf(buf, "%d.%d\n", (u8)(result>>8), (u8)result);
+}
+
+/* Get hardware version */
+static ssize_t show_hardware(struct device *d, struct device_attribute *attr,
+			     char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(d);
+	struct usb_8dev *dev = usb_get_intfdata(intf);
+	u16 result;
+	struct usb_8dev_cmd_msg inmsg;
+	struct usb_8dev_cmd_msg outmsg = {
+		.channel = 0,
+		.command = USB_8DEV_GET_HARDW_VER,
+		.opt1 = 0,
+		.opt2 = 0
+		};
+
+	int err = usb_8dev_send_cmd(dev, &outmsg, &inmsg);
+	if (err)
+		return -EIO;
+
+	result = be16_to_cpu(*(u16 *)inmsg.data);
+
+	return sprintf(buf, "%d.%d\n", (u8)(result>>8), (u8)result);
+}
+
+static DEVICE_ATTR(firmware, S_IRUGO, show_firmware, NULL);
+static DEVICE_ATTR(hardware, S_IRUGO, show_hardware, NULL);
+
+/*
+ * Set network device mode
+ *
+ * Maybe we should leave this function empty, because the device
+ * set mode variable with open command.
+ */
+static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
+{
+	struct usb_8dev *dev = netdev_priv(netdev);
+	int err = 0;
+
+	switch (mode) {
+	case CAN_MODE_START:
+		err = usb_8dev_cmd_open(dev);
+		if (err)
+			netdev_warn(netdev, "couldn't start device");
+		break;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+/* Read data and status frames */
+static void usb_8dev_rx_can_msg(struct usb_8dev *dev,
+				struct usb_8dev_rx_msg *msg)
+{
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	struct net_device_stats *stats = &dev->netdev->stats;
+
+	if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
+		skb = alloc_can_skb(dev->netdev, &cf);
+		if (!skb)
+			return;
+
+		cf->can_id = be32_to_cpu(msg->id);
+		cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
+
+		if (msg->flags & USB_8DEV_EXTID)
+			cf->can_id |= CAN_EFF_FLAG;
+
+		if (msg->flags & USB_8DEV_RTR)
+			cf->can_id |= CAN_RTR_FLAG;
+		else
+			memcpy(cf->data, msg->data, cf->can_dlc);
+	} else if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
+		   msg->flags == USB_8DEV_ERR_FLAG) {
+
+		/*
+		 * Error message:
+		 * byte 0: Status
+		 * byte 1: bit   7: Receive Passive
+		 * byte 1: bit 0-6: Receive Error Counter
+		 * byte 2: Transmit Error Counter
+		 * byte 3: Always 0 (maybe reserved for future use)
+		 */
+
+		u8 state = msg->data[0];
+		u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
+		u8 txerr = msg->data[2];
+		int rx_errors = 0;
+		int tx_errors = 0;
+
+		skb = alloc_can_err_skb(dev->netdev, &cf);
+		if (!skb)
+			return;
+
+		switch (state) {
+		case USB_8DEV_STATUSMSG_OK:
+			dev->can.state = CAN_STATE_ERROR_ACTIVE;
+			cf->can_id |= CAN_ERR_PROT;
+			cf->data[2] = CAN_ERR_PROT_ACTIVE;
+			break;
+		case USB_8DEV_STATUSMSG_BUSOFF:
+			dev->can.state = CAN_STATE_BUS_OFF;
+			cf->can_id |= CAN_ERR_BUSOFF;
+			can_bus_off(dev->netdev);
+			break;
+		case USB_8DEV_STATUSMSG_OVERRUN:
+		case USB_8DEV_STATUSMSG_BUSLIGHT:
+		case USB_8DEV_STATUSMSG_BUSHEAVY:
+			dev->can.state = CAN_STATE_ERROR_WARNING;
+			cf->can_id |= CAN_ERR_CRTL;
+			break;
+		default:
+			dev->can.state = CAN_STATE_ERROR_WARNING;
+			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+			dev->can.can_stats.bus_error++;
+			break;
+		}
+
+		switch (state) {
+		case USB_8DEV_STATUSMSG_ACK:
+			cf->can_id |= CAN_ERR_ACK;
+			tx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_CRC:
+			cf->data[2] |= CAN_ERR_PROT_BIT;
+			rx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_BIT0:
+			cf->data[2] |= CAN_ERR_PROT_BIT0;
+			tx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_BIT1:
+			cf->data[2] |= CAN_ERR_PROT_BIT1;
+			tx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_FORM:
+			cf->data[2] |= CAN_ERR_PROT_FORM;
+			rx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_STUFF:
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
+			rx_errors = 1;
+			break;
+		case USB_8DEV_STATUSMSG_OVERRUN:
+			cf->data[1] = (txerr > rxerr) ?
+				CAN_ERR_CRTL_TX_OVERFLOW :
+				CAN_ERR_CRTL_RX_OVERFLOW;
+			cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+			stats->rx_over_errors++;
+			break;
+		case USB_8DEV_STATUSMSG_BUSLIGHT:
+			cf->data[1] = (txerr > rxerr) ?
+				CAN_ERR_CRTL_TX_WARNING :
+				CAN_ERR_CRTL_RX_WARNING;
+			dev->can.can_stats.error_warning++;
+			break;
+		case USB_8DEV_STATUSMSG_BUSHEAVY:
+			cf->data[1] = (txerr > rxerr) ?
+				CAN_ERR_CRTL_TX_PASSIVE :
+				CAN_ERR_CRTL_RX_PASSIVE;
+			dev->can.can_stats.error_passive++;
+			break;
+		}
+
+		if (tx_errors) {
+			cf->data[2] |= CAN_ERR_PROT_TX;
+			stats->tx_errors++;
+		}
+
+		if (rx_errors)
+			stats->rx_errors++;
+
+		cf->data[6] = txerr;
+		cf->data[7] = rxerr;
+
+		dev->bec.txerr = txerr;
+		dev->bec.rxerr = rxerr;
+
+	} else {
+		netdev_warn(dev->netdev, "frame type %d unknown",
+			 msg->type);
+		return;
+	}
+
+	netif_rx(skb);
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->can_dlc;
+}
+
+/*
+ * Callback for reading data from device
+ *
+ * Check urb status, call read function and resubmit urb read operation.
+ */
+static void usb_8dev_read_bulk_callback(struct urb *urb)
+{
+	struct usb_8dev *dev = urb->context;
+	struct net_device *netdev;
+	int retval;
+	int pos = 0;
+
+	netdev = dev->netdev;
+
+	if (!netif_device_present(netdev))
+		return;
+
+	switch (urb->status) {
+	case 0: /* success */
+		break;
+
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+
+	default:
+		netdev_info(netdev, "Rx URB aborted (%d)\n",
+			 urb->status);
+		goto resubmit_urb;
+	}
+
+	while (pos < urb->actual_length) {
+		struct usb_8dev_rx_msg *msg;
+
+		if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
+			netdev_err(dev->netdev, "format error\n");
+			break;
+		}
+
+		msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
+		usb_8dev_rx_can_msg(dev, msg);
+
+		pos += sizeof(struct usb_8dev_rx_msg);
+	}
+
+resubmit_urb:
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_rcvbulkpipe(dev->udev, USB_8DEV_ENDP_DATA_RX),
+			  urb->transfer_buffer, RX_BUFFER_SIZE,
+			  usb_8dev_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 handler for write operations
+ *
+ * Free allocated buffers, check transmit status and
+ * calculate statistic.
+ */
+static void usb_8dev_write_bulk_callback(struct urb *urb)
+{
+	struct usb_8dev_tx_urb_context *context = urb->context;
+	struct usb_8dev *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);
+
+	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;
+
+	netif_wake_queue(netdev);
+}
+
+/* Send data to device */
+static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
+				      struct net_device *netdev)
+{
+	struct usb_8dev *dev = netdev_priv(netdev);
+	struct net_device_stats *stats = &netdev->stats;
+	struct can_frame *cf = (struct can_frame *) skb->data;
+	struct usb_8dev_tx_msg *msg;
+	struct urb *urb;
+	struct usb_8dev_tx_urb_context *context = NULL;
+	u8 *buf;
+	int i, err;
+	size_t size = sizeof(struct usb_8dev_tx_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) {
+		netdev_err(netdev, "No memory left for URBs\n");
+		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;
+	}
+
+	memset(buf, 0, size);
+
+	msg = (struct usb_8dev_tx_msg *)buf;
+	msg->begin = USB_8DEV_DATA_START;
+	msg->flags = 0x00;
+
+	if (cf->can_id & CAN_RTR_FLAG)
+		msg->flags |= USB_8DEV_RTR;
+
+	if (cf->can_id & CAN_EFF_FLAG)
+		msg->flags |= USB_8DEV_EXTID;
+
+	msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
+	msg->dlc = cf->can_dlc;
+	memcpy(msg->data, cf->data, cf->can_dlc);
+	msg->end = USB_8DEV_DATA_END;
+
+	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_free_coherent(dev->udev, size, buf, urb->transfer_dma);
+
+		netdev_warn(netdev, "couldn't find free context");
+
+		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, USB_8DEV_ENDP_DATA_TX),
+			  buf, size, usb_8dev_write_bulk_callback, context);
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	usb_anchor_urb(urb, &dev->tx_submitted);
+
+	can_put_echo_skb(skb, netdev, context->echo_index);
+
+	atomic_inc(&dev->active_tx_urbs);
+
+	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(err)) {
+		can_free_echo_skb(netdev, context->echo_index);
+
+		usb_unanchor_urb(urb);
+		usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
+		dev_kfree_skb(skb);
+
+		atomic_dec(&dev->active_tx_urbs);
+
+		if (err == -ENODEV) {
+			netif_device_detach(netdev);
+		} else {
+			netdev_warn(netdev, "failed tx_urb %d\n", err);
+
+			stats->tx_dropped++;
+		}
+	} else {
+		/* 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:
+	dev_kfree_skb(skb);
+	stats->tx_dropped++;
+
+	return NETDEV_TX_OK;
+}
+
+static int usb_8dev_get_berr_counter(const struct net_device *netdev,
+				     struct can_berr_counter *bec)
+{
+	struct usb_8dev *dev = netdev_priv(netdev);
+
+	bec->txerr = dev->bec.txerr;
+	bec->rxerr = dev->bec.rxerr;
+
+	return 0;
+}
+
+/* Start USB device */
+static int usb_8dev_start(struct usb_8dev *dev)
+{
+	struct net_device *netdev = dev->netdev;
+	int err, i;
+
+	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) {
+			netdev_err(netdev, "No memory left for URBs\n");
+			return -ENOMEM;
+		}
+
+		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
+					 &urb->transfer_dma);
+		if (!buf) {
+			netdev_err(netdev, "No memory left for USB buffer\n");
+			usb_free_urb(urb);
+			return -ENOMEM;
+		}
+
+		usb_fill_bulk_urb(urb, dev->udev,
+				  usb_rcvbulkpipe(dev->udev,
+						  USB_8DEV_ENDP_DATA_RX),
+				  buf, RX_BUFFER_SIZE,
+				  usb_8dev_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_free_coherent(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) {
+		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");
+
+	err = usb_8dev_cmd_open(dev);
+	if (err)
+		goto failed;
+
+	dev->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	return 0;
+
+failed:
+	if (err == -ENODEV)
+		netif_device_detach(dev->netdev);
+
+	netdev_warn(netdev, "couldn't submit control: %d\n", err);
+
+	return err;
+}
+
+/* Open USB device */
+static int usb_8dev_open(struct net_device *netdev)
+{
+	struct usb_8dev *dev = netdev_priv(netdev);
+	int err;
+
+	/* common open */
+	err = open_candev(netdev);
+	if (err)
+		return err;
+
+	/* finally start device */
+	err = usb_8dev_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 void unlink_all_urbs(struct usb_8dev *dev)
+{
+	int i;
+
+	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;
+}
+
+/* Close USB device */
+static int usb_8dev_close(struct net_device *netdev)
+{
+	struct usb_8dev *dev = netdev_priv(netdev);
+	int err = 0;
+
+	/* Send CLOSE command to CAN controller */
+	err = usb_8dev_cmd_close(dev);
+	if (err)
+		netdev_warn(netdev, "couldn't stop device");
+
+	dev->can.state = CAN_STATE_STOPPED;
+
+	/* Stop polling */
+	unlink_all_urbs(dev);
+
+	netif_stop_queue(netdev);
+
+	close_candev(netdev);
+
+	return err;
+}
+
+static const struct net_device_ops usb_8dev_netdev_ops = {
+	.ndo_open = usb_8dev_open,
+	.ndo_stop = usb_8dev_close,
+	.ndo_start_xmit = usb_8dev_start_xmit,
+};
+
+static const struct can_bittiming_const usb_8dev_bittiming_const = {
+	.name = "usb_8dev",
+	.tseg1_min = USB_8DEV_TSEG1_MIN,
+	.tseg1_max = USB_8DEV_TSEG1_MAX,
+	.tseg2_min = USB_8DEV_TSEG2_MIN,
+	.tseg2_max = USB_8DEV_TSEG2_MAX,
+	.sjw_max = USB_8DEV_SJW_MAX,
+	.brp_min = USB_8DEV_BRP_MIN,
+	.brp_max = USB_8DEV_BRP_MAX,
+	.brp_inc = USB_8DEV_BRP_INC,
+};
+
+/*
+ * Probe USB device
+ *
+ * Check device and firmware.
+ * Set supported modes and bittiming constants.
+ * Allocate some memory.
+ */
+static int usb_8dev_probe(struct usb_interface *intf,
+			 const struct usb_device_id *id)
+{
+	struct net_device *netdev;
+	struct usb_8dev *dev;
+	int i, err = -ENOMEM;
+	u32 version;
+	char buf[18];
+	struct usb_device *usbdev = interface_to_usbdev(intf);
+
+	/* product id looks strange, better we also check iProdukt string */
+	if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
+		       sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
+		dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
+		return -ENODEV;
+	}
+
+	netdev = alloc_candev(sizeof(struct usb_8dev), MAX_TX_URBS);
+	if (!netdev) {
+		dev_err(&intf->dev, "Couldn't alloc candev\n");
+		return -ENOMEM;
+	}
+
+	dev = netdev_priv(netdev);
+
+	dev->udev = usbdev;
+	dev->netdev = netdev;
+
+	dev->can.state = CAN_STATE_STOPPED;
+	dev->can.clock.freq = USB_8DEV_ABP_CLOCK;
+	dev->can.bittiming_const = &usb_8dev_bittiming_const;
+	dev->can.do_set_mode = usb_8dev_set_mode;
+	dev->can.do_get_berr_counter = usb_8dev_get_berr_counter;
+	dev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+				      CAN_CTRLMODE_LISTENONLY |
+				      CAN_CTRLMODE_ONE_SHOT;
+
+	netdev->netdev_ops = &usb_8dev_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->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg),
+				      GFP_KERNEL);
+	if (!dev->cmd_msg_buffer) {
+		netdev_err(netdev, "Couldn't alloc Tx buffer\n");
+		goto cleanup_candev;
+	}
+
+	usb_set_intfdata(intf, dev);
+
+	SET_NETDEV_DEV(netdev, &intf->dev);
+
+	mutex_init(&dev->usb_8dev_cmd_lock);
+
+	err = usb_8dev_cmd_version(dev, &version);
+	if (err) {
+		netdev_err(netdev, "can't get firmware version\n");
+		goto cleanup_cmd_msg_buffer;
+	} else {
+		netdev_info(netdev,
+			 "firmware: %d.%d, hardware: %d.%d\n",
+			 (version>>24) & 0xff, (version>>16) & 0xff,
+			 (version>>8) & 0xff, version & 0xff);
+	}
+
+	err = register_candev(netdev);
+	if (err) {
+		netdev_err(netdev,
+			"couldn't register CAN device: %d\n", err);
+		goto cleanup_cmd_msg_buffer;
+	}
+
+	if (device_create_file(&intf->dev, &dev_attr_firmware))
+		netdev_err(netdev,
+			"Couldn't create device file for firmware\n");
+
+	if (device_create_file(&intf->dev, &dev_attr_hardware))
+		netdev_err(netdev,
+			"Couldn't create device file for hardware\n");
+
+	/* let the user know what node this device is now attached to */
+	netdev_info(netdev, "device registered as %s\n", netdev->name);
+	return 0;
+
+cleanup_cmd_msg_buffer:
+	kfree(dev->cmd_msg_buffer);
+
+cleanup_candev:
+	free_candev(netdev);
+
+	return err;
+
+}
+
+/* Called by the usb core when driver is unloaded or device is removed */
+static void usb_8dev_disconnect(struct usb_interface *intf)
+{
+	struct usb_8dev *dev = usb_get_intfdata(intf);
+
+	device_remove_file(&intf->dev, &dev_attr_firmware);
+	device_remove_file(&intf->dev, &dev_attr_hardware);
+
+	usb_set_intfdata(intf, NULL);
+
+	if (dev) {
+		netdev_info(dev->netdev, "disconnect %s\n", dev->netdev->name);
+
+		unregister_netdev(dev->netdev);
+		free_candev(dev->netdev);
+
+		unlink_all_urbs(dev);
+	}
+
+}
+
+static struct usb_driver usb_8dev_driver = {
+	.name =		"usb_8dev",
+	.probe =	usb_8dev_probe,
+	.disconnect =	usb_8dev_disconnect,
+	.id_table =	usb_8dev_table,
+};
+
+module_usb_driver(usb_8dev_driver);
+
+MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
+MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
+MODULE_LICENSE("GPL v2");
-- 
1.7.10.4

Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

["Bernd Krumböck"]

> On 12/04/2012 11:11 PM, Marc Kleine-Budde wrote:
>> On 12/04/2012 11:43 PM, Bernd Krumboeck wrote:
>                 ^^^^^^^^
>
> btw: your clock is wrong by about 1h :)

Corrected. I like UTC system clock, but Windows doesn't.

Bernd

Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Wolfgang Grandegger]

Hi Bernd,

still a few issues with error handling.

> +/* Send open command to device */
> +static int usb_8dev_cmd_open(struct usb_8dev *dev)
> +{
> +    struct can_bittiming *bt = &dev->can.bittiming;
> +    struct usb_8dev_cmd_msg outmsg;
> +    struct usb_8dev_cmd_msg inmsg;
> +    u32 flags = 0;
> +    u32 beflags;
> +    u16 bebrp;
> +    u32 ctrlmode = dev->can.ctrlmode;
> +
> +    if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
> +        flags |= USB_8DEV_LOOPBACK;
> +    if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
> +        flags |= USB_8DEV_SILENT;
> +    if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
> +        flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
> +
> +    flags |= USB_8DEV_STATUS_FRAME;
> +
> +    memset(&outmsg, 0, sizeof(struct usb_8dev_cmd_msg));

sizeof(outmsg) is better, here and maybe in other places.

> +    outmsg.command = USB_8DEV_OPEN;
> +    outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
> +    outmsg.data[0] = (bt->prop_seg + bt->phase_seg1);

Minor issue. Brackets not needed.

> +    outmsg.data[1] = bt->phase_seg2;
> +    outmsg.data[2] = bt->sjw;
> +
> +    /* BRP */
> +    bebrp = cpu_to_be16((u16) bt->brp);
> +    memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
> +
> +    /* flags */
> +    beflags = cpu_to_be32(flags);
> +    memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
> +
> +    return usb_8dev_send_cmd(dev, &outmsg, &inmsg);
> +}
...
> +
> +/* Read data and status frames */
> +static void usb_8dev_rx_can_msg(struct usb_8dev *dev,
> +                struct usb_8dev_rx_msg *msg)
> +{
> +    struct can_frame *cf;
> +    struct sk_buff *skb;
> +    struct net_device_stats *stats = &dev->netdev->stats;
> +
> +    if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
> +        skb = alloc_can_skb(dev->netdev, &cf);
> +        if (!skb)
> +            return;
> +
> +        cf->can_id = be32_to_cpu(msg->id);
> +        cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
> +
> +        if (msg->flags & USB_8DEV_EXTID)
> +            cf->can_id |= CAN_EFF_FLAG;
> +
> +        if (msg->flags & USB_8DEV_RTR)
> +            cf->can_id |= CAN_RTR_FLAG;
> +        else
> +            memcpy(cf->data, msg->data, cf->can_dlc);
> +    } else if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
> +           msg->flags == USB_8DEV_ERR_FLAG) {
> +
> +        /*
> +         * Error message:
> +         * byte 0: Status
> +         * byte 1: bit   7: Receive Passive
> +         * byte 1: bit 0-6: Receive Error Counter
> +         * byte 2: Transmit Error Counter
> +         * byte 3: Always 0 (maybe reserved for future use)
> +         */
> +
> +        u8 state = msg->data[0];
> +        u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
> +        u8 txerr = msg->data[2];
> +        int rx_errors = 0;
> +        int tx_errors = 0;
> +
> +        skb = alloc_can_err_skb(dev->netdev, &cf);
> +        if (!skb)
> +            return;
> +
> +        switch (state) {
> +        case USB_8DEV_STATUSMSG_OK:
> +            dev->can.state = CAN_STATE_ERROR_ACTIVE;
> +            cf->can_id |= CAN_ERR_PROT;
> +            cf->data[2] = CAN_ERR_PROT_ACTIVE;
> +            break;
> +        case USB_8DEV_STATUSMSG_BUSOFF:
> +            dev->can.state = CAN_STATE_BUS_OFF;
> +            cf->can_id |= CAN_ERR_BUSOFF;
> +            can_bus_off(dev->netdev);
> +            break;
> +        case USB_8DEV_STATUSMSG_OVERRUN:

Overrun is not a bus-erroror state change. It should be treated
separately. More below...

> +        case USB_8DEV_STATUSMSG_BUSLIGHT:
> +        case USB_8DEV_STATUSMSG_BUSHEAVY:
> +            dev->can.state = CAN_STATE_ERROR_WARNING;

Please set the state below when you re-treat BUSLIGHT and BUSHEAVY.

> +            cf->can_id |= CAN_ERR_CRTL;
> +            break;
> +        default:
> +            dev->can.state = CAN_STATE_ERROR_WARNING;

Bus-errors do not necessarily change the state. Please remove.

> +            cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +            dev->can.can_stats.bus_error++;
> +            break;
> +        }
> +
> +        switch (state) {
> +        case USB_8DEV_STATUSMSG_ACK:
> +            cf->can_id |= CAN_ERR_ACK;
> +            tx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_CRC:
> +            cf->data[2] |= CAN_ERR_PROT_BIT;
> +            rx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_BIT0:
> +            cf->data[2] |= CAN_ERR_PROT_BIT0;
> +            tx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_BIT1:
> +            cf->data[2] |= CAN_ERR_PROT_BIT1;
> +            tx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_FORM:
> +            cf->data[2] |= CAN_ERR_PROT_FORM;
> +            rx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_STUFF:
> +            cf->data[2] |= CAN_ERR_PROT_STUFF;
> +            rx_errors = 1;
> +            break;
> +        case USB_8DEV_STATUSMSG_OVERRUN:
> +            cf->data[1] = (txerr > rxerr) ?
> +                CAN_ERR_CRTL_TX_OVERFLOW :
> +                CAN_ERR_CRTL_RX_OVERFLOW;
> +            cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
> +            stats->rx_over_errors++;

The overrun normally means the a message could not be received because
the hardware was busy (FIFO full). It does not depend on the tx/rxerrs
and we only set CAN_ERR_CRTL_RX_OVERFLOW. As good example please check:

http://lxr.linux.no/#linux+v3.6.9/drivers/net/can/usb/ems_usb.c#L335

> +            break;
> +        case USB_8DEV_STATUSMSG_BUSLIGHT:

               dev->can.state = CAN_STATE_ERROR_WARNING;

> +            cf->data[1] = (txerr > rxerr) ?
> +                CAN_ERR_CRTL_TX_WARNING :
> +                CAN_ERR_CRTL_RX_WARNING;
> +            dev->can.can_stats.error_warning++;
> +            break;
> +        case USB_8DEV_STATUSMSG_BUSHEAVY:

               dev->can.state = CAN_STATE_ERROR_PASSIVE;

> +            cf->data[1] = (txerr > rxerr) ?
> +                CAN_ERR_CRTL_TX_PASSIVE :
> +                CAN_ERR_CRTL_RX_PASSIVE;
> +            dev->can.can_stats.error_passive++;
> +            break;
> +        }
> +
> +        if (tx_errors) {
> +            cf->data[2] |= CAN_ERR_PROT_TX;
> +            stats->tx_errors++;
> +        }
> +
> +        if (rx_errors)
> +            stats->rx_errors++;
> +
> +        cf->data[6] = txerr;
> +        cf->data[7] = rxerr;
> +
> +        dev->bec.txerr = txerr;
> +        dev->bec.rxerr = rxerr;
> +
> +    } else {
> +        netdev_warn(dev->netdev, "frame type %d unknown",
> +             msg->type);
> +        return;
> +    }
> +
> +    netif_rx(skb);
> +
> +    stats->rx_packets++;
> +    stats->rx_bytes += cf->can_dlc;
> +}

Wolfgang.

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Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Oliver Hartkopp]

On 05.12.2012 11:13, Wolfgang Grandegger wrote:

>> +    outmsg.command = USB_8DEV_OPEN;
>> +    outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
>> +    outmsg.data[0] = (bt->prop_seg + bt->phase_seg1);
>
> Minor issue. Brackets not needed.
>
>> +    outmsg.data[1] = bt->phase_seg2;
>> +    outmsg.data[2] = bt->sjw;
>> +

That's correct from a compilers point of view.
But in this case i would preserve the [0] as it is better to read in 
conjunction with the two lines below ( ..[1] ..[2] )

The semantic has to be understood by humans ;-)

Regards,
Oliver

Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Marc Kleine-Budde]

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On 12/05/2012 04:49 PM, Oliver Hartkopp wrote:
> On 05.12.2012 11:13, Wolfgang Grandegger wrote:
> 
>>> +    outmsg.command = USB_8DEV_OPEN;
>>> +    outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
>>> +    outmsg.data[0] = (bt->prop_seg + bt->phase_seg1);
>>
>> Minor issue. Brackets not needed.
>>
>>> +    outmsg.data[1] = bt->phase_seg2;
>>> +    outmsg.data[2] = bt->sjw;
>>> +
> 
> That's correct from a compilers point of view.
> But in this case i would preserve the [0] as it is better to read in
> conjunction with the two lines below ( ..[1] ..[2] )
> 
> The semantic has to be understood by humans ;-)

I think Wolfgang was talking about the round bracket not the square
bracket. :D

Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
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Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Wolfgang Grandegger]

On 12/05/2012 05:00 PM, Marc Kleine-Budde wrote:
> On 12/05/2012 04:49 PM, Oliver Hartkopp wrote:
>> On 05.12.2012 11:13, Wolfgang Grandegger wrote:
>>
>>>> +    outmsg.command = USB_8DEV_OPEN;
>>>> +    outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
>>>> +    outmsg.data[0] = (bt->prop_seg + bt->phase_seg1);
>>>
>>> Minor issue. Brackets not needed.
>>>
>>>> +    outmsg.data[1] = bt->phase_seg2;
>>>> +    outmsg.data[2] = bt->sjw;
>>>> +
>>
>> That's correct from a compilers point of view.
>> But in this case i would preserve the [0] as it is better to read in
>> conjunction with the two lines below ( ..[1] ..[2] )
>>
>> The semantic has to be understood by humans ;-)
> 
> I think Wolfgang was talking about the round bracket not the square
> bracket. :D

Yep. Sorry for confusion.

Wolfgang.


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Re: [PATCH v4] usb_8dev: Add support for USB2CAN interface from 8 devices

[Marc Kleine-Budde]

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On 12/04/2012 11:43 PM, Bernd Krumboeck wrote:
> Add device driver for USB2CAN interface from "8 devices"
> (http://www.8devices.com).

[...]

> +/* Send data to device */
> +static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
> +                      struct net_device *netdev)
> +{
> +    struct usb_8dev *dev = netdev_priv(netdev);

I just noticed, it's unusual to name you private data pointer "dev", I
suggest to name it priv. Maybe you can rename your private data struct
to: "struct usb_8dev_priv".

> +    struct net_device_stats *stats = &netdev->stats;
> +    struct can_frame *cf = (struct can_frame *) skb->data;
> +    struct usb_8dev_tx_msg *msg;
> +    struct urb *urb;
> +    struct usb_8dev_tx_urb_context *context = NULL;

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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