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
pl_vendor_req(struct usbnet * dev,u8 req,u8 val,u8 index)58 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
59 {
60 return usbnet_read_cmd(dev, req,
61 USB_DIR_IN | USB_TYPE_VENDOR |
62 USB_RECIP_DEVICE,
63 val, index, NULL, 0);
64 }
65
66 static inline int
pl_clear_QuickLink_features(struct usbnet * dev,int val)67 pl_clear_QuickLink_features(struct usbnet *dev, int val)
68 {
69 return pl_vendor_req(dev, 1, (u8) val, 0);
70 }
71
72 static inline int
pl_set_QuickLink_features(struct usbnet * dev,int val)73 pl_set_QuickLink_features(struct usbnet *dev, int val)
74 {
75 return pl_vendor_req(dev, 3, (u8) val, 0);
76 }
77
pl_reset(struct usbnet * dev)78 static int pl_reset(struct usbnet *dev)
79 {
80 int status;
81
82 /* some units seem to need this reset, others reject it utterly.
83 * FIXME be more like "naplink" or windows drivers.
84 */
85 status = pl_set_QuickLink_features(dev,
86 PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
87 if (status != 0 && netif_msg_probe(dev))
88 netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
89 return 0;
90 }
91
92 static const struct driver_info prolific_info = {
93 .description = "Prolific PL-2301/PL-2302/PL-25A1/PL-27A1",
94 .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT,
95 /* some PL-2302 versions seem to fail usb_set_interface() */
96 .reset = pl_reset,
97 };
98
99
100 /*-------------------------------------------------------------------------*/
101
102 /*
103 * Proilific's name won't normally be on the cables, and
104 * may not be on the device.
105 */
106
107 static const struct usb_device_id products [] = {
108
109 /* full speed cables */
110 {
111 USB_DEVICE(0x067b, 0x0000), // PL-2301
112 .driver_info = (unsigned long) &prolific_info,
113 }, {
114 USB_DEVICE(0x067b, 0x0001), // PL-2302
115 .driver_info = (unsigned long) &prolific_info,
116 },
117
118 /* high speed cables */
119 {
120 USB_DEVICE(0x067b, 0x25a1), /* PL-25A1, no eeprom */
121 .driver_info = (unsigned long) &prolific_info,
122 }, {
123 USB_DEVICE(0x050d, 0x258a), /* Belkin F5U258/F5U279 (PL-25A1) */
124 .driver_info = (unsigned long) &prolific_info,
125 }, {
126 USB_DEVICE(0x3923, 0x7825), /* National Instruments USB
127 * Host-to-Host Cable
128 */
129 .driver_info = (unsigned long) &prolific_info,
130
131 },
132
133 /* super speed cables */
134 {
135 USB_DEVICE(0x067b, 0x27a1), /* PL-27A1, no eeprom
136 * also: goobay Active USB 3.0
137 * Data Link,
138 * Unitek Y-3501
139 */
140 .driver_info = (unsigned long) &prolific_info,
141 },
142
143 { }, // END
144 };
145 MODULE_DEVICE_TABLE(usb, products);
146
147 static struct usb_driver plusb_driver = {
148 .name = "plusb",
149 .id_table = products,
150 .probe = usbnet_probe,
151 .disconnect = usbnet_disconnect,
152 .suspend = usbnet_suspend,
153 .resume = usbnet_resume,
154 .disable_hub_initiated_lpm = 1,
155 };
156
157 module_usb_driver(plusb_driver);
158
159 MODULE_AUTHOR("David Brownell");
160 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver");
161 MODULE_LICENSE("GPL");
162