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, see <http://www.gnu.org/licenses/>.
17 */
18
19// #define	DEBUG			// error path messages, extra info
20// #define	VERBOSE			// more; success messages
21
22#include <linux/module.h>
23#include <linux/netdevice.h>
24#include <linux/etherdevice.h>
25#include <linux/ethtool.h>
26#include <linux/workqueue.h>
27#include <linux/mii.h>
28#include <linux/usb.h>
29#include <linux/usb/usbnet.h>
30
31
32/*
33 * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
34 *
35 * The protocol and handshaking used here should be bug-compatible
36 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
37 *
38 * HEADS UP:  this handshaking isn't all that robust.  This driver
39 * gets confused easily if you unplug one end of the cable then
40 * try to connect it again; you'll need to restart both ends. The
41 * "naplink" software (used by some PlayStation/2 deveopers) does
42 * the handshaking much better!   Also, sometimes this hardware
43 * seems to get wedged under load.  Prolific docs are weak, and
44 * don't identify differences between PL2301 and PL2302, much less
45 * anything to explain the different PL2302 versions observed.
46 *
47 * NOTE:  pl2501 has several modes, including pl2301 and pl2302
48 * compatibility.   Some docs suggest the difference between 2301
49 * and 2302 is only to make MS-Windows use a different driver...
50 *
51 * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
52 * this chip are as usual incomplete about what control messages
53 * are supported.
54 */
55
56/*
57 * Bits 0-4 can be used for software handshaking; they're set from
58 * one end, cleared from the other, "read" with the interrupt byte.
59 */
60#define	PL_S_EN		(1<<7)		/* (feature only) suspend enable */
61/* reserved bit -- rx ready (6) ? */
62#define	PL_TX_READY	(1<<5)		/* (interrupt only) transmit ready */
63#define	PL_RESET_OUT	(1<<4)		/* reset output pipe */
64#define	PL_RESET_IN	(1<<3)		/* reset input pipe */
65#define	PL_TX_C		(1<<2)		/* transmission complete */
66#define	PL_TX_REQ	(1<<1)		/* transmission received */
67#define	PL_PEER_E	(1<<0)		/* peer exists */
68
69static inline int
70pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
71{
72	return usbnet_read_cmd(dev, req,
73				USB_DIR_IN | USB_TYPE_VENDOR |
74				USB_RECIP_DEVICE,
75				val, index, NULL, 0);
76}
77
78static inline int
79pl_clear_QuickLink_features(struct usbnet *dev, int val)
80{
81	return pl_vendor_req(dev, 1, (u8) val, 0);
82}
83
84static inline int
85pl_set_QuickLink_features(struct usbnet *dev, int val)
86{
87	return pl_vendor_req(dev, 3, (u8) val, 0);
88}
89
90static int pl_reset(struct usbnet *dev)
91{
92	int status;
93
94	/* some units seem to need this reset, others reject it utterly.
95	 * FIXME be more like "naplink" or windows drivers.
96	 */
97	status = pl_set_QuickLink_features(dev,
98		PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
99	if (status != 0 && netif_msg_probe(dev))
100		netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
101	return 0;
102}
103
104static const struct driver_info	prolific_info = {
105	.description =	"Prolific PL-2301/PL-2302/PL-25A1",
106	.flags =	FLAG_POINTTOPOINT | FLAG_NO_SETINT,
107		/* some PL-2302 versions seem to fail usb_set_interface() */
108	.reset =	pl_reset,
109};
110
111
112/*-------------------------------------------------------------------------*/
113
114/*
115 * Proilific's name won't normally be on the cables, and
116 * may not be on the device.
117 */
118
119static const struct usb_device_id	products [] = {
120
121/* full speed cables */
122{
123	USB_DEVICE(0x067b, 0x0000),	// PL-2301
124	.driver_info =	(unsigned long) &prolific_info,
125}, {
126	USB_DEVICE(0x067b, 0x0001),	// PL-2302
127	.driver_info =	(unsigned long) &prolific_info,
128},
129
130/* high speed cables */
131{
132	USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
133	.driver_info =  (unsigned long) &prolific_info,
134}, {
135	USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
136	.driver_info =  (unsigned long) &prolific_info,
137}, {
138	USB_DEVICE(0x3923, 0x7825),     /* National Instruments USB
139					 * Host-to-Host Cable
140					 */
141	.driver_info =  (unsigned long) &prolific_info,
142},
143
144	{ },		// END
145};
146MODULE_DEVICE_TABLE(usb, products);
147
148static struct usb_driver plusb_driver = {
149	.name =		"plusb",
150	.id_table =	products,
151	.probe =	usbnet_probe,
152	.disconnect =	usbnet_disconnect,
153	.suspend =	usbnet_suspend,
154	.resume =	usbnet_resume,
155	.disable_hub_initiated_lpm = 1,
156};
157
158module_usb_driver(plusb_driver);
159
160MODULE_AUTHOR("David Brownell");
161MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
162MODULE_LICENSE("GPL");
163