1/*
2 * PL-2301/2302 USB host-to-host link cables
3 * Copyright (C) 2000-2005 by David Brownell
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18 */
19
20// #define	DEBUG			// error path messages, extra info
21// #define	VERBOSE			// more; success messages
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/netdevice.h>
26#include <linux/etherdevice.h>
27#include <linux/ethtool.h>
28#include <linux/workqueue.h>
29#include <linux/mii.h>
30#include <linux/usb.h>
31
32#include "usbnet.h"
33
34
35/*
36 * Prolific PL-2301/PL-2302 driver ... http://www.prolifictech.com
37 *
38 * The protocol and handshaking used here should be bug-compatible
39 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
40 *
41 * HEADS UP:  this handshaking isn't all that robust.  This driver
42 * gets confused easily if you unplug one end of the cable then
43 * try to connect it again; you'll need to restart both ends. The
44 * "naplink" software (used by some PlayStation/2 deveopers) does
45 * the handshaking much better!   Also, sometimes this hardware
46 * seems to get wedged under load.  Prolific docs are weak, and
47 * don't identify differences between PL2301 and PL2302, much less
48 * anything to explain the different PL2302 versions observed.
49 */
50
51/*
52 * Bits 0-4 can be used for software handshaking; they're set from
53 * one end, cleared from the other, "read" with the interrupt byte.
54 */
55#define	PL_S_EN		(1<<7)		/* (feature only) suspend enable */
56/* reserved bit -- rx ready (6) ? */
57#define	PL_TX_READY	(1<<5)		/* (interrupt only) transmit ready */
58#define	PL_RESET_OUT	(1<<4)		/* reset output pipe */
59#define	PL_RESET_IN	(1<<3)		/* reset input pipe */
60#define	PL_TX_C		(1<<2)		/* transmission complete */
61#define	PL_TX_REQ	(1<<1)		/* transmission received */
62#define	PL_PEER_E	(1<<0)		/* peer exists */
63
64static inline int
65pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
66{
67	return usb_control_msg(dev->udev,
68		usb_rcvctrlpipe(dev->udev, 0),
69		req,
70		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
71		val, index,
72		NULL, 0,
73		USB_CTRL_GET_TIMEOUT);
74}
75
76static inline int
77pl_clear_QuickLink_features(struct usbnet *dev, int val)
78{
79	return pl_vendor_req(dev, 1, (u8) val, 0);
80}
81
82static inline int
83pl_set_QuickLink_features(struct usbnet *dev, int val)
84{
85	return pl_vendor_req(dev, 3, (u8) val, 0);
86}
87
88static int pl_reset(struct usbnet *dev)
89{
90	(void) pl_set_QuickLink_features(dev,
91		PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
92	return 0;
93}
94
95static const struct driver_info	prolific_info = {
96	.description =	"Prolific PL-2301/PL-2302",
97	.flags =	FLAG_NO_SETINT,
98		/* some PL-2302 versions seem to fail usb_set_interface() */
99	.reset =	pl_reset,
100};
101
102
103/*-------------------------------------------------------------------------*/
104
105/*
106 * Proilific's name won't normally be on the cables, and
107 * may not be on the device.
108 */
109
110static const struct usb_device_id	products [] = {
111
112{
113	USB_DEVICE(0x067b, 0x0000),	// PL-2301
114	.driver_info =	(unsigned long) &prolific_info,
115}, {
116	USB_DEVICE(0x067b, 0x0001),	// PL-2302
117	.driver_info =	(unsigned long) &prolific_info,
118},
119
120	{ },		// END
121};
122MODULE_DEVICE_TABLE(usb, products);
123
124static struct usb_driver plusb_driver = {
125	.name =		"plusb",
126	.id_table =	products,
127	.probe =	usbnet_probe,
128	.disconnect =	usbnet_disconnect,
129	.suspend =	usbnet_suspend,
130	.resume =	usbnet_resume,
131};
132
133static int __init plusb_init(void)
134{
135 	return usb_register(&plusb_driver);
136}
137module_init(plusb_init);
138
139static void __exit plusb_exit(void)
140{
141 	usb_deregister(&plusb_driver);
142}
143module_exit(plusb_exit);
144
145MODULE_AUTHOR("David Brownell");
146MODULE_DESCRIPTION("Prolific PL-2301/2302 USB Host to Host Link Driver");
147MODULE_LICENSE("GPL");
148