Re: [PATCH v7] usb_8dev: Add support for USB2CAN interface from 8 devices

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 12/13/2012 07:40 PM, Bernd Krumboeck wrote:
> Add device driver for USB2CAN interface from "8 devices" (http://www.8devices.com).
> 
> changes since v6:
> * changed some variable types to big endian equivalent
> * small cleanups
> 
> changes since v5:
> * unlock mutex on error
> 
> changes since v4:
> * removed FSF address
> * renamed struct usb_8dev
> * removed unused variable free_slots
> * replaced some _to_cpu functions with pointer equivalent
> * fix return value for usb_8dev_set_mode
> * handle can errors with separate function
> * fix overrun error handling
> * rewrite error handling for usb_8dev_start_xmit
> * fix urb submit in usb_8dev_start
> * various small fixes
> 
> Signed-off-by: Bernd Krumboeck <krumboeck@universalnet.at>

Looks good to me. Minor style issue inline. Please provide a
documentation for the sysfs entries and place it under:
Documentation/ABI/testing/sysfs-platform.

I'd like to have a final Ack from Wolfgang regarding the error handling.

regards,
Marc
> ---
>  drivers/net/can/usb/Kconfig    |    6 +
>  drivers/net/can/usb/Makefile   |    1 +
>  drivers/net/can/usb/usb_8dev.c | 1094 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1101 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..d9c681b
> --- /dev/null
> +++ b/drivers/net/can/usb/usb_8dev.c
> @@ -0,0 +1,1094 @@
> +/*
> + * 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.
> + *
> + * 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_priv *priv;
> +
> +	u32 echo_index;
> +	u8 dlc;
> +};
> +
> +/* Structure to hold all of our device specific stuff */
> +struct usb_8dev_priv {
> +	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;
> +
> +	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 int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
> +{
> +	int actual_length;
> +
> +	return usb_bulk_msg(priv->udev,
> +			    usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
> +			    msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
> +}
> +
> +static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
> +				int *actual_length)
> +{
> +	return usb_bulk_msg(priv->udev,
> +			    usb_rcvbulkpipe(priv->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_priv *priv,
> +			     struct usb_8dev_cmd_msg *out,
> +			     struct usb_8dev_cmd_msg *in)
> +{
> +	int err;
> +	int num_bytes_read;
> +	struct net_device *netdev;
> +
> +	netdev = priv->netdev;
> +
> +	out->begin = USB_8DEV_CMD_START;
> +	out->end = USB_8DEV_CMD_END;
> +
> +	mutex_lock(&priv->usb_8dev_cmd_lock);
> +
> +	memcpy(priv->cmd_msg_buffer, out,
> +		sizeof(struct usb_8dev_cmd_msg));
> +
> +	err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
> +				    sizeof(struct usb_8dev_cmd_msg));
> +	if (err < 0) {
> +		netdev_err(netdev, "sending command message failed\n");
> +		goto failed;
> +	}
> +
> +	err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
> +				    sizeof(struct usb_8dev_cmd_msg),
> +				    &num_bytes_read);
> +	if (err < 0) {
> +		netdev_err(netdev, "no command message answer\n");
> +		goto failed;
> +	}
> +
> +	memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
> +
> +	if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
> +			num_bytes_read != 16 || in->opt1 != 0)
> +		err = -EPROTO;
> +
> +failed:
> +	mutex_unlock(&priv->usb_8dev_cmd_lock);
> +	return err;
> +}
> +
> +/* Send open command to device */
> +static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
> +{
> +	struct can_bittiming *bt = &priv->can.bittiming;
> +	struct usb_8dev_cmd_msg outmsg;
> +	struct usb_8dev_cmd_msg inmsg;
> +	u32 ctrlmode = priv->can.ctrlmode;
> +	u32 flags = USB_8DEV_STATUS_FRAME;
> +	__be32 beflags;
> +	__be16 bebrp;
> +
> +	memset(&outmsg, 0, sizeof(outmsg));
> +	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 */
> +	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;
> +
> +	beflags = cpu_to_be32(flags);
> +	memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
> +
> +	return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
> +}
> +
> +/* Send close command to device */
> +static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
> +{
> +	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(priv, &outmsg, &inmsg);
> +}
> +
> +/* Get firmware and hardware version */
> +static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, 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(priv, &outmsg, &inmsg);
> +	if (err)
> +		return err;
> +
> +	*res = be32_to_cpup((__be32 *)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_priv *priv = 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
> +		};

please adjust the closing bracket one tab to the left.

> +
> +	int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
> +	if (err)
> +		return -EIO;
> +
> +	result = be16_to_cpup((__be16 *)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_priv *priv = 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(priv, &outmsg, &inmsg);
> +	if (err)
> +		return -EIO;
> +
> +	result = be16_to_cpup((__be16 *)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_priv *priv = netdev_priv(netdev);
> +	int err = 0;
> +
> +	switch (mode) {
> +	case CAN_MODE_START:
> +		err = usb_8dev_cmd_open(priv);
> +		if (err)
> +			netdev_warn(netdev, "couldn't start device");
> +		break;
> +
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return err;
> +}
> +
> +/* Read error/status frames */
> +static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
> +				struct usb_8dev_rx_msg *msg)
> +{
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +	struct net_device_stats *stats = &priv->netdev->stats;
> +
> +	/*
> +	 * 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(priv->netdev, &cf);
> +	if (!skb)
> +		return;
> +
> +	switch (state) {
> +	case USB_8DEV_STATUSMSG_OK:
> +		priv->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:
> +		priv->can.state = CAN_STATE_BUS_OFF;
> +		cf->can_id |= CAN_ERR_BUSOFF;
> +		can_bus_off(priv->netdev);
> +		break;
> +	case USB_8DEV_STATUSMSG_OVERRUN:
> +	case USB_8DEV_STATUSMSG_BUSLIGHT:
> +	case USB_8DEV_STATUSMSG_BUSHEAVY:
> +		cf->can_id |= CAN_ERR_CRTL;
> +		break;
> +	default:
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +		priv->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] = CAN_ERR_CRTL_RX_OVERFLOW;
> +		stats->rx_over_errors++;
> +		rx_errors = 1;
> +		break;
> +	case USB_8DEV_STATUSMSG_BUSLIGHT:
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +		cf->data[1] = (txerr > rxerr) ?
> +			CAN_ERR_CRTL_TX_WARNING :
> +			CAN_ERR_CRTL_RX_WARNING;
> +		priv->can.can_stats.error_warning++;
> +		break;
> +	case USB_8DEV_STATUSMSG_BUSHEAVY:
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +		cf->data[1] = (txerr > rxerr) ?
> +			CAN_ERR_CRTL_TX_PASSIVE :
> +			CAN_ERR_CRTL_RX_PASSIVE;
> +		priv->can.can_stats.error_passive++;
> +		break;
> +	default:
> +		netdev_warn(priv->netdev,
> +			    "Unknown status/error message (%d)\n", state);
> +		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;
> +
> +	priv->bec.txerr = txerr;
> +	priv->bec.rxerr = rxerr;
> +
> +	netif_rx(skb);
> +
> +	stats->rx_packets++;
> +	stats->rx_bytes += cf->can_dlc;
> +}
> +
> +/* Read data and status frames */
> +static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
> +				struct usb_8dev_rx_msg *msg)
> +{
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +	struct net_device_stats *stats = &priv->netdev->stats;
> +
> +	if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
> +		   msg->flags == USB_8DEV_ERR_FLAG) {
> +		usb_8dev_rx_err_msg(priv, msg);
> +	} else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
> +		skb = alloc_can_skb(priv->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);
> +
> +		netif_rx(skb);
> +
> +		stats->rx_packets++;
> +		stats->rx_bytes += cf->can_dlc;
> +	} else {
> +		netdev_warn(priv->netdev, "frame type %d unknown",
> +			 msg->type);
> +	}
> +
> +}
> +
> +/*
> + * 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_priv *priv = urb->context;
> +	struct net_device *netdev;
> +	int retval;
> +	int pos = 0;
> +
> +	netdev = priv->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(priv->netdev, "format error\n");
> +			break;
> +		}
> +
> +		msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
> +		usb_8dev_rx_can_msg(priv, msg);
> +
> +		pos += sizeof(struct usb_8dev_rx_msg);
> +	}
> +
> +resubmit_urb:
> +	usb_fill_bulk_urb(urb, priv->udev,
> +			  usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
> +			  urb->transfer_buffer, RX_BUFFER_SIZE,
> +			  usb_8dev_read_bulk_callback, priv);
> +
> +	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_priv *priv;
> +	struct net_device *netdev;
> +
> +	BUG_ON(!context);
> +
> +	priv = context->priv;
> +	netdev = priv->netdev;
> +
> +	/* free up our allocated buffer */
> +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> +			  urb->transfer_buffer, urb->transfer_dma);
> +
> +	atomic_dec(&priv->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_priv *priv = 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(priv->udev, size, GFP_ATOMIC,
> +				 &urb->transfer_dma);
> +	if (!buf) {
> +		netdev_err(netdev, "No memory left for USB buffer\n");
> +		goto nomembuf;
> +	}
> +
> +	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 (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
> +			context = &priv->tx_contexts[i];
> +			break;
> +		}
> +	}
> +
> +	/*
> +	 * May never happen! When this happens we'd more URBs in flight as
> +	 * allowed (MAX_TX_URBS).
> +	 */
> +	if (!context)
> +		goto nofreecontext;
> +
> +	context->priv = priv;
> +	context->echo_index = i;
> +	context->dlc = cf->can_dlc;
> +
> +	usb_fill_bulk_urb(urb, priv->udev,
> +			  usb_sndbulkpipe(priv->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, &priv->tx_submitted);
> +
> +	can_put_echo_skb(skb, netdev, context->echo_index);
> +
> +	atomic_inc(&priv->active_tx_urbs);
> +
> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (unlikely(err))
> +		goto failed;
> +	else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
> +		/* Slow down tx path */
> +		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;
> +
> +nofreecontext:
> +	usb_unanchor_urb(urb);
> +	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
> +
> +	netdev_warn(netdev, "couldn't find free context");
> +
> +	return NETDEV_TX_BUSY;
> +
> +failed:
> +	can_free_echo_skb(netdev, context->echo_index);
> +
> +	usb_unanchor_urb(urb);
> +	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
> +
> +	atomic_dec(&priv->active_tx_urbs);
> +
> +	if (err == -ENODEV)
> +		netif_device_detach(netdev);
> +	else
> +		netdev_warn(netdev, "failed tx_urb %d\n", err);
> +
> +nomembuf:
> +	usb_free_urb(urb);
> +
> +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_priv *priv = netdev_priv(netdev);
> +
> +	bec->txerr = priv->bec.txerr;
> +	bec->rxerr = priv->bec.rxerr;
> +
> +	return 0;
> +}
> +
> +/* Start USB device */
> +static int usb_8dev_start(struct usb_8dev_priv *priv)
> +{
> +	struct net_device *netdev = priv->netdev;
> +	int err, i;
> +
> +	for (i = 0; i < MAX_RX_URBS; i++) {
> +		struct urb *urb = NULL;
> +		u8 *buf;
> +
> +		/* 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");
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		buf = usb_alloc_coherent(priv->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);
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		usb_fill_bulk_urb(urb, priv->udev,
> +				  usb_rcvbulkpipe(priv->udev,
> +						  USB_8DEV_ENDP_DATA_RX),
> +				  buf, RX_BUFFER_SIZE,
> +				  usb_8dev_read_bulk_callback, priv);
> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +		usb_anchor_urb(urb, &priv->rx_submitted);
> +
> +		err = usb_submit_urb(urb, GFP_KERNEL);
> +		if (err) {
> +			usb_unanchor_urb(urb);
> +			usb_free_coherent(priv->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(priv);
> +	if (err)
> +		goto failed;
> +
> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> +	return 0;
> +
> +failed:
> +	if (err == -ENODEV)
> +		netif_device_detach(priv->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_priv *priv = netdev_priv(netdev);
> +	int err;
> +
> +	/* common open */
> +	err = open_candev(netdev);
> +	if (err)
> +		return err;
> +
> +	/* finally start device */
> +	err = usb_8dev_start(priv);
> +	if (err) {
> +		if (err == -ENODEV)
> +			netif_device_detach(priv->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_priv *priv)
> +{
> +	int i;
> +
> +	usb_kill_anchored_urbs(&priv->rx_submitted);
> +
> +	usb_kill_anchored_urbs(&priv->tx_submitted);
> +	atomic_set(&priv->active_tx_urbs, 0);
> +
> +	for (i = 0; i < MAX_TX_URBS; i++)
> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> +}
> +
> +/* Close USB device */
> +static int usb_8dev_close(struct net_device *netdev)
> +{
> +	struct usb_8dev_priv *priv = netdev_priv(netdev);
> +	int err = 0;
> +
> +	/* Send CLOSE command to CAN controller */
> +	err = usb_8dev_cmd_close(priv);
> +	if (err)
> +		netdev_warn(netdev, "couldn't stop device");
> +
> +	priv->can.state = CAN_STATE_STOPPED;
> +
> +	netif_stop_queue(netdev);
> +
> +	/* Stop polling */
> +	unlink_all_urbs(priv);
> +
> +	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_priv *priv;
> +	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 iProduct 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_priv), MAX_TX_URBS);
> +	if (!netdev) {
> +		dev_err(&intf->dev, "Couldn't alloc candev\n");
> +		return -ENOMEM;
> +	}
> +
> +	priv = netdev_priv(netdev);
> +
> +	priv->udev = usbdev;
> +	priv->netdev = netdev;
> +
> +	priv->can.state = CAN_STATE_STOPPED;
> +	priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
> +	priv->can.bittiming_const = &usb_8dev_bittiming_const;
> +	priv->can.do_set_mode = usb_8dev_set_mode;
> +	priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
> +	priv->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(&priv->rx_submitted);
> +
> +	init_usb_anchor(&priv->tx_submitted);
> +	atomic_set(&priv->active_tx_urbs, 0);
> +
> +	for (i = 0; i < MAX_TX_URBS; i++)
> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
> +
> +	priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg),
> +				      GFP_KERNEL);
> +	if (!priv->cmd_msg_buffer) {
> +		netdev_err(netdev, "Couldn't alloc Tx buffer\n");
> +		goto cleanup_candev;
> +	}
> +
> +	usb_set_intfdata(intf, priv);
> +
> +	SET_NETDEV_DEV(netdev, &intf->dev);
> +
> +	mutex_init(&priv->usb_8dev_cmd_lock);
> +
> +	err = register_candev(netdev);
> +	if (err) {
> +		netdev_err(netdev,
> +			"couldn't register CAN device: %d\n", err);
> +		goto cleanup_cmd_msg_buffer;
> +	}
> +
> +	err = usb_8dev_cmd_version(priv, &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);
> +	}
> +
> +	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");
> +
> +	return 0;
> +
> +cleanup_cmd_msg_buffer:
> +	kfree(priv->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_priv *priv = 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 (priv) {
> +		netdev_info(priv->netdev, "device disconnected\n");
> +
> +		unregister_netdev(priv->netdev);
> +		free_candev(priv->netdev);
> +
> +		unlink_all_urbs(priv);
> +	}
> +
> +}
> +
> +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");
> 


-- 
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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