xref: /linux/drivers/net/usb/plusb.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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 #include <linux/usb/usbnet.h>
32 
33 
34 /*
35  * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
36  *
37  * The protocol and handshaking used here should be bug-compatible
38  * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
39  *
40  * HEADS UP:  this handshaking isn't all that robust.  This driver
41  * gets confused easily if you unplug one end of the cable then
42  * try to connect it again; you'll need to restart both ends. The
43  * "naplink" software (used by some PlayStation/2 deveopers) does
44  * the handshaking much better!   Also, sometimes this hardware
45  * seems to get wedged under load.  Prolific docs are weak, and
46  * don't identify differences between PL2301 and PL2302, much less
47  * anything to explain the different PL2302 versions observed.
48  *
49  * NOTE:  pl2501 has several modes, including pl2301 and pl2302
50  * compatibility.   Some docs suggest the difference between 2301
51  * and 2302 is only to make MS-Windows use a different driver...
52  *
53  * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
54  * this chip are as usual incomplete about what control messages
55  * are supported.
56  */
57 
58 /*
59  * Bits 0-4 can be used for software handshaking; they're set from
60  * one end, cleared from the other, "read" with the interrupt byte.
61  */
62 #define	PL_S_EN		(1<<7)		/* (feature only) suspend enable */
63 /* reserved bit -- rx ready (6) ? */
64 #define	PL_TX_READY	(1<<5)		/* (interrupt only) transmit ready */
65 #define	PL_RESET_OUT	(1<<4)		/* reset output pipe */
66 #define	PL_RESET_IN	(1<<3)		/* reset input pipe */
67 #define	PL_TX_C		(1<<2)		/* transmission complete */
68 #define	PL_TX_REQ	(1<<1)		/* transmission received */
69 #define	PL_PEER_E	(1<<0)		/* peer exists */
70 
71 static inline int
72 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
73 {
74 	return usb_control_msg(dev->udev,
75 		usb_rcvctrlpipe(dev->udev, 0),
76 		req,
77 		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
78 		val, index,
79 		NULL, 0,
80 		USB_CTRL_GET_TIMEOUT);
81 }
82 
83 static inline int
84 pl_clear_QuickLink_features(struct usbnet *dev, int val)
85 {
86 	return pl_vendor_req(dev, 1, (u8) val, 0);
87 }
88 
89 static inline int
90 pl_set_QuickLink_features(struct usbnet *dev, int val)
91 {
92 	return pl_vendor_req(dev, 3, (u8) val, 0);
93 }
94 
95 static int pl_reset(struct usbnet *dev)
96 {
97 	int status;
98 
99 	/* some units seem to need this reset, others reject it utterly.
100 	 * FIXME be more like "naplink" or windows drivers.
101 	 */
102 	status = pl_set_QuickLink_features(dev,
103 		PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
104 	if (status != 0 && netif_msg_probe(dev))
105 		netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
106 	return 0;
107 }
108 
109 static const struct driver_info	prolific_info = {
110 	.description =	"Prolific PL-2301/PL-2302/PL-25A1",
111 	.flags =	FLAG_POINTTOPOINT | FLAG_NO_SETINT,
112 		/* some PL-2302 versions seem to fail usb_set_interface() */
113 	.reset =	pl_reset,
114 };
115 
116 
117 /*-------------------------------------------------------------------------*/
118 
119 /*
120  * Proilific's name won't normally be on the cables, and
121  * may not be on the device.
122  */
123 
124 static const struct usb_device_id	products [] = {
125 
126 /* full speed cables */
127 {
128 	USB_DEVICE(0x067b, 0x0000),	// PL-2301
129 	.driver_info =	(unsigned long) &prolific_info,
130 }, {
131 	USB_DEVICE(0x067b, 0x0001),	// PL-2302
132 	.driver_info =	(unsigned long) &prolific_info,
133 },
134 
135 /* high speed cables */
136 {
137 	USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
138 	.driver_info =  (unsigned long) &prolific_info,
139 }, {
140 	USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
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