Prolific 2501 link cable

[Tobias <tobiasarp@xxxxxx>]

Hi,

i have created a working driver for prolifc pl2501/2302 bases link cables.
This driver does interoperate with the windows driver provided by prolific.
It would be great if someone can do some tests too. I tested it on between
kernel 2.6.15 and windows XP (SP2) (please turn off the firewall if you have 
SP2). 

Please let me know if something is wrong with this driver.

Regards

Tobias

/*
 * PL-2301/2302/2501 USB host-to-host link cables
 * Copyright (C) 2007 by Tobias Arp (arp@xxxxxxxxxx)
 *
 *  This driver does now work with Windows driver from Prolific:
 *    http://www.prolific.com.tw/support/files/sp_pl2502NW_v20044.zip
 *
 * Copyright (C) 2000-2005 by David Brownell
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

// #define	DEBUG			// error path messages, extra info
// #define	VERBOSE			// more; success messages

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>

#include "usbnet.h"

/*
 * Prolific PL-2301/PL-2302 driver ... http://www.prolifictech.com
 *
 * The protocol and handshaking used here should be bug-compatible
 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
 *
 * HEADS UP:  this handshaking isn't all that robust.  This driver
 * gets confused easily if you unplug one end of the cable then
 * try to connect it again; you'll need to restart both ends. The
 * "naplink" software (used by some PlayStation/2 deveopers) does
 * the handshaking much better!   Also, sometimes this hardware
 * seems to get wedged under load.  Prolific docs are weak, and
 * don't identify differences between PL2301 and PL2302, much less
 * anything to explain the different PL2302 versions observed.
 */

// max packet length
#define PL_MAX_PACKET_LEN			1520

/*
 * Bits 0-4 can be used for software handshaking; they're set from
 * one end, cleared from the other, "read" with the interrupt byte.
 */
#define	PL_S_EN		(1<<7)		/* (feature only) suspend enable */
/* reserved bit -- rx ready (6) ? */
#define	PL_TX_READY	(1<<5)		/* (interrupt only) transmit ready */
#define	PL_RESET_OUT	(1<<4)		/* reset output pipe */
#define	PL_RESET_IN	(1<<3)		/* reset input pipe */
#define	PL_TX_C		(1<<2)		/* transmission complete */
#define	PL_TX_REQ	(1<<1)		/* transmission received */
#define	PL_PEER_E	(1<<0)		/* peer exists */

static inline int
pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
{
	return usb_control_msg(dev->udev,
		usb_rcvctrlpipe(dev->udev, 0),
		req,
		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
		val, index,
		NULL, 0,
		USB_CTRL_SET_TIMEOUT);
}

static inline int
pl_clear_QuickLink_features(struct usbnet *dev, int val)
{
	return pl_vendor_req(dev, USB_REQ_CLEAR_FEATURE, (u8) val, 0);
}

static inline int
pl_set_QuickLink_features(struct usbnet *dev, int val)
{
	return pl_vendor_req(dev, USB_REQ_SET_FEATURE, (u8) val, 0);
}

static int pl_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
	u32	iLen;

	iLen = le32_to_cpu(*((u32 *)skb->data));

	if (iLen > PL_MAX_PACKET_LEN)
	{
		dbg("pl: invalid received packet size: %d",iLen);
		return 0;
	}

	skb_pull(skb,4);

	return 1;
}

static struct sk_buff *pl_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
	int 	padlen;
	int	length = skb->len;
	int	headroom = skb_headroom(skb);
	int	tailroom = skb_tailroom(skb);
	u32	*packet_len;

	// FIXME:  magic numbers, bleech
	padlen = (skb->len + (4  % 64)) ? 0 : 1;

	if ((!skb_cloned(skb))
			&& ((headroom + tailroom) >= (padlen + 4))) {
		if ((headroom < 4) || (tailroom < padlen)) {
			skb->data = memmove(skb->head + 4,
					     skb->data, skb->len);
			skb->tail = skb->data + skb->len;
		}
	} else {
		struct sk_buff	*skb2;
		skb2 = skb_copy_expand(skb,4,padlen,flags);
		dev_kfree_skb_any(skb);
		skb = skb2;
		if (!skb)
			return NULL;
	}

	// attach the packet count to the header
	packet_len = (u32 *) skb_push(skb,4);

	*packet_len = cpu_to_le32(length);

	return skb;
}

static int pl_reset(struct usbnet *dev)
{
	(void) pl_set_QuickLink_features(dev,PL_TX_REQ);
	(void) pl_set_QuickLink_features(dev,PL_RESET_IN);
	(void) pl_set_QuickLink_features(dev,PL_RESET_OUT);

	mdelay(50);	

	(void) pl_set_QuickLink_features(dev,PL_PEER_E);

	return 0;
}

static const struct driver_info	prolific_info = {
	.description =	"Prolific PL-2301/PL-2302",
	.flags =	FLAG_NO_SETINT,
		/* some PL-2302 versions seem to fail usb_set_interface() */
	.reset =	pl_reset,
	.rx_fixup =	pl_rx_fixup,
	.tx_fixup =	pl_tx_fixup,
};


/*-------------------------------------------------------------------------*/

/*
 * Proilific's name won't normally be on the cables, and
 * may not be on the device.
 */

static const struct usb_device_id	products [] = {

{
	USB_DEVICE(0x067b, 0x0000),	// PL-2301
	.driver_info =	(unsigned long) &prolific_info,
}, {
	USB_DEVICE(0x067b, 0x0001),	// PL-2302
	.driver_info =	(unsigned long) &prolific_info,
}, {
	USB_DEVICE(0x067b, 0x2501),	// PL-2501
	.driver_info =	(unsigned long) &prolific_info,
},
	{ },		// END
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver plusb_driver = {
	.name =		"plusb",
	.id_table =	products,
	.probe =	usbnet_probe,
	.disconnect =	usbnet_disconnect,
	.suspend =	usbnet_suspend,
	.resume =	usbnet_resume,
};

static int __init plusb_init(void)
{
 	return usb_register(&plusb_driver);
}
module_init(plusb_init);

static void __exit plusb_exit(void)
{
 	usb_deregister(&plusb_driver);
}
module_exit(plusb_exit);

MODULE_AUTHOR("Tobias Arp");
MODULE_DESCRIPTION("Prolific PL-2301/2302/2501 USB Host to Host Link Driver");
MODULE_LICENSE("GPL");

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/

_______________________________________________
linux-usb-devel@xxxxxxxxxxxxxxxxxxxxx
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel