diff options
Diffstat (limited to 'drivers/net/can/usb/usb_8dev.c')
| -rw-r--r-- | drivers/net/can/usb/usb_8dev.c | 1035 | 
1 files changed, 1035 insertions, 0 deletions
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c new file mode 100644 index 00000000000..ef674ecb82f --- /dev/null +++ b/drivers/net/can/usb/usb_8dev.c @@ -0,0 +1,1035 @@ +/* + * 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/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> +#include <linux/can/led.h> + +/* driver constants */ +#define MAX_RX_URBS			20 +#define MAX_TX_URBS			20 +#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 +}; + +/* device CAN clock */ +#define USB_8DEV_ABP_CLOCK		32000000 + +/* 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 +}; + +/* command options */ +#define USB_8DEV_BAUD_MANUAL		0x09 +#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		0x27  /* 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; +} + +/* 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_OK: +	case USB_8DEV_STATUSMSG_BUSOFF: +		break; +	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_UNSPEC; +		cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ | +			       CAN_ERR_PROT_LOC_CRC_DEL; +		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_PASSIVE; +		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; + +		can_led_event(priv->netdev, CAN_LED_EVENT_RX); +	} 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); + +	can_led_event(netdev, CAN_LED_EVENT_TX); + +	/* 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_free_coherent(priv->udev, size, buf, urb->transfer_dma); +	usb_free_urb(urb); + +	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); +			usb_free_urb(urb); +			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; + +	can_led_event(netdev, CAN_LED_EVENT_OPEN); + +	/* 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); + +	can_led_event(netdev, CAN_LED_EVENT_STOP); + +	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, +	.ndo_change_mtu = can_change_mtu, +}; + +static const struct can_bittiming_const usb_8dev_bittiming_const = { +	.name = "usb_8dev", +	.tseg1_min = 1, +	.tseg1_max = 16, +	.tseg2_min = 1, +	.tseg2_max = 8, +	.sjw_max = 4, +	.brp_min = 1, +	.brp_max = 1024, +	.brp_inc = 1, +}; + +/* 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) +		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_unregister_candev; +	} else { +		netdev_info(netdev, +			 "firmware: %d.%d, hardware: %d.%d\n", +			 (version>>24) & 0xff, (version>>16) & 0xff, +			 (version>>8) & 0xff, version & 0xff); +	} + +	devm_can_led_init(netdev); + +	return 0; + +cleanup_unregister_candev: +	unregister_netdev(priv->netdev); + +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); + +	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");  | 
