xref: /linux/drivers/net/usb/plusb.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 
69 static inline int
70 pl_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 
78 static inline int
79 pl_clear_QuickLink_features(struct usbnet *dev, int val)
80 {
81 	return pl_vendor_req(dev, 1, (u8) val, 0);
82 }
83 
84 static inline int
85 pl_set_QuickLink_features(struct usbnet *dev, int val)
86 {
87 	return pl_vendor_req(dev, 3, (u8) val, 0);
88 }
89 
90 static 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 
104 static 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 
119 static 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 };
146 MODULE_DEVICE_TABLE(usb, products);
147 
148 static 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 
158 module_usb_driver(plusb_driver);
159 
160 MODULE_AUTHOR("David Brownell");
161 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
162 MODULE_LICENSE("GPL");
163