path: root/drivers/net/can/usb/esd_usb2.c

/*
 * CAN driver for esd CAN-USB/2
 *
 * Copyright (C) 2010 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
 *
 * 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.
 */
#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>

MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 interfaces");
MODULE_LICENSE("GPL v2");

/* Define these values to match your devices */
#define USB_ESDGMBH_VENDOR_ID	0x0ab4
#define USB_CANUSB2_PRODUCT_ID	0x0010

#define ESD_USB2_CAN_CLOCK	60000000
#define ESD_USB2_MAX_NETS	2

/* USB2 commands */
#define CMD_VERSION		1 /* also used for VERSION_REPLY */
#define CMD_CAN_RX		2 /* device to host only */
#define CMD_CAN_TX		3 /* also used for TX_DONE */
#define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
#define CMD_TS			5 /* also used for TS_REPLY */
#define CMD_IDADD		6 /* also used for IDADD_REPLY */

/* esd CAN message flags - dlc field */
#define ESD_RTR			0x10

/* esd CAN message flags - id field */
#define ESD_EXTID		0x20000000
#define ESD_EVENT		0x40000000
#define ESD_IDMASK		0x1fffffff

/* esd CAN event ids used by this driver */
#define ESD_EV_CAN_ERROR_EXT	2

/* baudrate message flags */
#define ESD_USB2_UBR		0x80000000
#define ESD_USB2_LOM		0x40000000
#define ESD_USB2_NO_BAUDRATE	0x7fffffff
#define ESD_USB2_TSEG1_MIN	1
#define ESD_USB2_TSEG1_MAX	16
#define ESD_USB2_TSEG1_SHIFT	16
#define ESD_USB2_TSEG2_MIN	1
#define ESD_USB2_TSEG2_MAX	8
#define ESD_USB2_TSEG2_SHIFT	20
#define ESD_USB2_SJW_MAX	4
#define ESD_USB2_SJW_SHIFT	14
#define ESD_USB2_BRP_MIN	1
#define ESD_USB2_BRP_MAX	1024
#define ESD_USB2_BRP_INC	1
#define ESD_USB2_3_SAMPLES	0x00800000

/* esd IDADD message */
#define ESD_ID_ENABLE		0x80
#define ESD_MAX_ID_SEGMENT	64

/* SJA1000 ECC register (emulated by usb2 firmware) */
#define SJA1000_ECC_SEG		0x1F
#define SJA1000_ECC_DIR		0x20
#define SJA1000_ECC_ERR		0x06
#define SJA1000_ECC_BIT		0x00
#define SJA1000_ECC_FORM	0x40
#define SJA1000_ECC_STUFF	0x80
#define SJA1000_ECC_MASK	0xc0

/* esd bus state event codes */
#define ESD_BUSSTATE_MASK	0xc0
#define ESD_BUSSTATE_WARN	0x40
#define ESD_BUSSTATE_ERRPASSIVE	0x80
#define ESD_BUSSTATE_BUSOFF	0xc0

#define RX_BUFFER_SIZE		1024
#define MAX_RX_URBS		4
#define MAX_TX_URBS		16 /* must be power of 2 */

struct header_msg {
	u8 len; /* len is always the total message length in 32bit words */
	u8 cmd;
	u8 rsvd[2];
};

struct version_msg {
	u8 len;
	u8 cmd;
	u8 rsvd;
	u8 flags;
	__le32 drv_version;
};

struct version_reply_msg {
	u8 len;
	u8 cmd;
	u8 nets;
	u8 features;
	__le32 version;
	u8 name[16];
	__le32 rsvd;
	__le32 ts;
};

struct rx_msg {
	u8 len;
	u8 cmd;
	u8 net;
	u8 dlc;
	__le32 ts;
	__le32 id; /* upper 3 bits contain flags */
	u8 data[8];
};

struct tx_msg {
	u8 len;
	u8 cmd;
	u8 net;
	u8 dlc;
	__le32 hnd;
	__le32 id; /* upper 3 bits contain flags */
	u8 data[8];
};

struct tx_done_msg {
	u8 len;
	u8 cmd;
	u8 net;
	u8 status;
	__le32 hnd;
	__le32 ts;
};

struct id_filter_msg {
	u8 len;
	u8 cmd;
	u8 net;
	u8 option;
	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
};

struct set_baudrate_msg {
	u8 len;
	u8 cmd;
	u8 net;
	u8 rsvd;
	__le32 baud;
};

/* Main message type used between library and application */
struct __attribute__ ((packed)) esd_usb2_msg {
	union {
		struct header_msg hdr;
		struct version_msg version;
		struct version_reply_msg version_reply;
		struct rx_msg rx;
		struct tx_msg tx;
		struct tx_done_msg txdone;
		struct set_baudrate_msg setbaud;
		struct id_filter_msg filter;
	} msg;
};

static struct usb_device_id esd_usb2_table[] = {
	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
	{}
};
MODULE_DEVICE_TABLE(usb, esd_usb2_table);

struct esd_usb2_net_priv;

struct esd_tx_urb_context {
	struct esd_usb2_net_priv *priv;
	u32 echo_index;
	int dlc;
};

struct esd_usb2 {
	struct usb_device *udev;
	struct esd_usb2_net_priv *nets