1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * PL-2301/2302 USB host-to-host link cables |
4 | * Copyright (C) 2000-2005 by David Brownell |
5 | */ |
6 | |
7 | // #define DEBUG // error path messages, extra info |
8 | // #define VERBOSE // more; success messages |
9 | |
10 | #include <linux/module.h> |
11 | #include <linux/netdevice.h> |
12 | #include <linux/etherdevice.h> |
13 | #include <linux/ethtool.h> |
14 | #include <linux/workqueue.h> |
15 | #include <linux/mii.h> |
16 | #include <linux/usb.h> |
17 | #include <linux/usb/usbnet.h> |
18 | |
19 | |
20 | /* |
21 | * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/ |
22 | * |
23 | * The protocol and handshaking used here should be bug-compatible |
24 | * with the Linux 2.2 "plusb" driver, by Deti Fliegl. |
25 | * |
26 | * HEADS UP: this handshaking isn't all that robust. This driver |
27 | * gets confused easily if you unplug one end of the cable then |
28 | * try to connect it again; you'll need to restart both ends. The |
29 | * "naplink" software (used by some PlayStation/2 developers) does |
30 | * the handshaking much better! Also, sometimes this hardware |
31 | * seems to get wedged under load. Prolific docs are weak, and |
32 | * don't identify differences between PL2301 and PL2302, much less |
33 | * anything to explain the different PL2302 versions observed. |
34 | * |
35 | * NOTE: pl2501 has several modes, including pl2301 and pl2302 |
36 | * compatibility. Some docs suggest the difference between 2301 |
37 | * and 2302 is only to make MS-Windows use a different driver... |
38 | * |
39 | * pl25a1 glue based on patch from Tony Gibbs. Prolific "docs" on |
40 | * this chip are as usual incomplete about what control messages |
41 | * are supported. |
42 | */ |
43 | |
44 | /* |
45 | * Bits 0-4 can be used for software handshaking; they're set from |
46 | * one end, cleared from the other, "read" with the interrupt byte. |
47 | */ |
48 | #define PL_S_EN (1<<7) /* (feature only) suspend enable */ |
49 | /* reserved bit -- rx ready (6) ? */ |
50 | #define PL_TX_READY (1<<5) /* (interrupt only) transmit ready */ |
51 | #define PL_RESET_OUT (1<<4) /* reset output pipe */ |
52 | #define PL_RESET_IN (1<<3) /* reset input pipe */ |
53 | #define PL_TX_C (1<<2) /* transmission complete */ |
54 | #define PL_TX_REQ (1<<1) /* transmission received */ |
55 | #define PL_PEER_E (1<<0) /* peer exists */ |
56 | |
57 | static inline int |
58 | pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index) |
59 | { |
60 | return usbnet_write_cmd(dev, cmd: req, USB_TYPE_VENDOR | USB_RECIP_DEVICE, |
61 | value: val, index, NULL, size: 0); |
62 | } |
63 | |
64 | static inline int |
65 | pl_set_QuickLink_features(struct usbnet *dev, int val) |
66 | { |
67 | return pl_vendor_req(dev, req: 3, val: (u8) val, index: 0); |
68 | } |
69 | |
70 | static int pl_reset(struct usbnet *dev) |
71 | { |
72 | int status; |
73 | |
74 | /* some units seem to need this reset, others reject it utterly. |
75 | * FIXME be more like "naplink" or windows drivers. |
76 | */ |
77 | status = pl_set_QuickLink_features(dev, |
78 | PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E); |
79 | if (status != 0 && netif_msg_probe(dev)) |
80 | netif_dbg(dev, link, dev->net, "pl_reset --> %d\n" , status); |
81 | return 0; |
82 | } |
83 | |
84 | static const struct driver_info prolific_info = { |
85 | .description = "Prolific PL-2301/PL-2302/PL-25A1/PL-27A1" , |
86 | .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT, |
87 | /* some PL-2302 versions seem to fail usb_set_interface() */ |
88 | .reset = pl_reset, |
89 | }; |
90 | |
91 | |
92 | /*-------------------------------------------------------------------------*/ |
93 | |
94 | /* |
95 | * Proilific's name won't normally be on the cables, and |
96 | * may not be on the device. |
97 | */ |
98 | |
99 | static const struct usb_device_id products [] = { |
100 | |
101 | /* full speed cables */ |
102 | { |
103 | USB_DEVICE(0x067b, 0x0000), // PL-2301 |
104 | .driver_info = (unsigned long) &prolific_info, |
105 | }, { |
106 | USB_DEVICE(0x067b, 0x0001), // PL-2302 |
107 | .driver_info = (unsigned long) &prolific_info, |
108 | }, |
109 | |
110 | /* high speed cables */ |
111 | { |
112 | USB_DEVICE(0x067b, 0x25a1), /* PL-25A1, no eeprom */ |
113 | .driver_info = (unsigned long) &prolific_info, |
114 | }, { |
115 | USB_DEVICE(0x050d, 0x258a), /* Belkin F5U258/F5U279 (PL-25A1) */ |
116 | .driver_info = (unsigned long) &prolific_info, |
117 | }, { |
118 | USB_DEVICE(0x3923, 0x7825), /* National Instruments USB |
119 | * Host-to-Host Cable |
120 | */ |
121 | .driver_info = (unsigned long) &prolific_info, |
122 | |
123 | }, |
124 | |
125 | /* super speed cables */ |
126 | { |
127 | USB_DEVICE(0x067b, 0x27a1), /* PL-27A1, no eeprom |
128 | * also: goobay Active USB 3.0 |
129 | * Data Link, |
130 | * Unitek Y-3501 |
131 | */ |
132 | .driver_info = (unsigned long) &prolific_info, |
133 | }, |
134 | |
135 | { }, // END |
136 | }; |
137 | MODULE_DEVICE_TABLE(usb, products); |
138 | |
139 | static struct usb_driver plusb_driver = { |
140 | .name = "plusb" , |
141 | .id_table = products, |
142 | .probe = usbnet_probe, |
143 | .disconnect = usbnet_disconnect, |
144 | .suspend = usbnet_suspend, |
145 | .resume = usbnet_resume, |
146 | .disable_hub_initiated_lpm = 1, |
147 | }; |
148 | |
149 | module_usb_driver(plusb_driver); |
150 | |
151 | MODULE_AUTHOR("David Brownell" ); |
152 | MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver" ); |
153 | MODULE_LICENSE("GPL" ); |
154 | |