xref: /linux/drivers/net/usb/plusb.c (revision 2d87650a3bf1b80f7d0d150ee1af3f8a89e5b7aa)
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/init.h>
24 #include <linux/netdevice.h>
25 #include <linux/etherdevice.h>
26 #include <linux/ethtool.h>
27 #include <linux/workqueue.h>
28 #include <linux/mii.h>
29 #include <linux/usb.h>
30 #include <linux/usb/usbnet.h>
31 
32 
33 /*
34  * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
35  *
36  * The protocol and handshaking used here should be bug-compatible
37  * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
38  *
39  * HEADS UP:  this handshaking isn't all that robust.  This driver
40  * gets confused easily if you unplug one end of the cable then
41  * try to connect it again; you'll need to restart both ends. The
42  * "naplink" software (used by some PlayStation/2 deveopers) does
43  * the handshaking much better!   Also, sometimes this hardware
44  * seems to get wedged under load.  Prolific docs are weak, and
45  * don't identify differences between PL2301 and PL2302, much less
46  * anything to explain the different PL2302 versions observed.
47  *
48  * NOTE:  pl2501 has several modes, including pl2301 and pl2302
49  * compatibility.   Some docs suggest the difference between 2301
50  * and 2302 is only to make MS-Windows use a different driver...
51  *
52  * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
53  * this chip are as usual incomplete about what control messages
54  * are supported.
55  */
56 
57 /*
58  * Bits 0-4 can be used for software handshaking; they're set from
59  * one end, cleared from the other, "read" with the interrupt byte.
60  */
61 #define	PL_S_EN		(1<<7)		/* (feature only) suspend enable */
62 /* reserved bit -- rx ready (6) ? */
63 #define	PL_TX_READY	(1<<5)		/* (interrupt only) transmit ready */
64 #define	PL_RESET_OUT	(1<<4)		/* reset output pipe */
65 #define	PL_RESET_IN	(1<<3)		/* reset input pipe */
66 #define	PL_TX_C		(1<<2)		/* transmission complete */
67 #define	PL_TX_REQ	(1<<1)		/* transmission received */
68 #define	PL_PEER_E	(1<<0)		/* peer exists */
69 
70 static inline int
71 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
72 {
73 	return usbnet_read_cmd(dev, req,
74 				USB_DIR_IN | USB_TYPE_VENDOR |
75 				USB_RECIP_DEVICE,
76 				val, index, NULL, 0);
77 }
78 
79 static inline int
80 pl_clear_QuickLink_features(struct usbnet *dev, int val)
81 {
82 	return pl_vendor_req(dev, 1, (u8) val, 0);
83 }
84 
85 static inline int
86 pl_set_QuickLink_features(struct usbnet *dev, int val)
87 {
88 	return pl_vendor_req(dev, 3, (u8) val, 0);
89 }
90 
91 static int pl_reset(struct usbnet *dev)
92 {
93 	int status;
94 
95 	/* some units seem to need this reset, others reject it utterly.
96 	 * FIXME be more like "naplink" or windows drivers.
97 	 */
98 	status = pl_set_QuickLink_features(dev,
99 		PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
100 	if (status != 0 && netif_msg_probe(dev))
101 		netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
102 	return 0;
103 }
104 
105 static const struct driver_info	prolific_info = {
106 	.description =	"Prolific PL-2301/PL-2302/PL-25A1",
107 	.flags =	FLAG_POINTTOPOINT | FLAG_NO_SETINT,
108 		/* some PL-2302 versions seem to fail usb_set_interface() */
109 	.reset =	pl_reset,
110 };
111 
112 
113 /*-------------------------------------------------------------------------*/
114 
115 /*
116  * Proilific's name won't normally be on the cables, and
117  * may not be on the device.
118  */
119 
120 static const struct usb_device_id	products [] = {
121 
122 /* full speed cables */
123 {
124 	USB_DEVICE(0x067b, 0x0000),	// PL-2301
125 	.driver_info =	(unsigned long) &prolific_info,
126 }, {
127 	USB_DEVICE(0x067b, 0x0001),	// PL-2302
128 	.driver_info =	(unsigned long) &prolific_info,
129 },
130 
131 /* high speed cables */
132 {
133 	USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
134 	.driver_info =  (unsigned long) &prolific_info,
135 }, {
136 	USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
137 	.driver_info =  (unsigned long) &prolific_info,
138 },
139 
140 	{ },		// END
141 };
142 MODULE_DEVICE_TABLE(usb, products);
143 
144 static struct usb_driver plusb_driver = {
145 	.name =		"plusb",
146 	.id_table =	products,
147 	.probe =	usbnet_probe,
148 	.disconnect =	usbnet_disconnect,
149 	.suspend =	usbnet_suspend,
150 	.resume =	usbnet_resume,
151 	.disable_hub_initiated_lpm = 1,
152 };
153 
154 module_usb_driver(plusb_driver);
155 
156 MODULE_AUTHOR("David Brownell");
157 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
158 MODULE_LICENSE("GPL");
159