net/usb/plusb.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * PL-2301/2302 USB host-to-host link cables
0004  * Copyright (C) 2000-2005 by David Brownell
0005  */
0006
0007 // #define  DEBUG           // error path messages, extra info
0008 // #define  VERBOSE         // more; success messages
0009
0010 #include <linux/module.h>
0011 #include <linux/netdevice.h>
0012 #include <linux/etherdevice.h>
0013 #include <linux/ethtool.h>
0014 #include <linux/workqueue.h>
0015 #include <linux/mii.h>
0016 #include <linux/usb.h>
0017 #include <linux/usb/usbnet.h>
0018
0019
0020 /*
0021  * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
0022  *
0023  * The protocol and handshaking used here should be bug-compatible
0024  * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
0025  *
0026  * HEADS UP:  this handshaking isn't all that robust.  This driver
0027  * gets confused easily if you unplug one end of the cable then
0028  * try to connect it again; you'll need to restart both ends. The
0029  * "naplink" software (used by some PlayStation/2 developers) does
0030  * the handshaking much better!   Also, sometimes this hardware
0031  * seems to get wedged under load.  Prolific docs are weak, and
0032  * don't identify differences between PL2301 and PL2302, much less
0033  * anything to explain the different PL2302 versions observed.
0034  *
0035  * NOTE:  pl2501 has several modes, including pl2301 and pl2302
0036  * compatibility.   Some docs suggest the difference between 2301
0037  * and 2302 is only to make MS-Windows use a different driver...
0038  *
0039  * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
0040  * this chip are as usual incomplete about what control messages
0041  * are supported.
0042  */
0043
0044 /*
0045  * Bits 0-4 can be used for software handshaking; they're set from
0046  * one end, cleared from the other, "read" with the interrupt byte.
0047  */
0048 #define PL_S_EN     (1<<7)      /* (feature only) suspend enable */
0049 /* reserved bit -- rx ready (6) ? */
0050 #define PL_TX_READY (1<<5)      /* (interrupt only) transmit ready */
0051 #define PL_RESET_OUT    (1<<4)      /* reset output pipe */
0052 #define PL_RESET_IN (1<<3)      /* reset input pipe */
0053 #define PL_TX_C     (1<<2)      /* transmission complete */
0054 #define PL_TX_REQ   (1<<1)      /* transmission received */
0055 #define PL_PEER_E   (1<<0)      /* peer exists */
0056
0057 static inline int
0058 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
0059 {
0060     return usbnet_read_cmd(dev, req,
0061                 USB_DIR_IN | USB_TYPE_VENDOR |
0062                 USB_RECIP_DEVICE,
0063                 val, index, NULL, 0);
0064 }
0065
0066 static inline int
0067 pl_clear_QuickLink_features(struct usbnet *dev, int val)
0068 {
0069     return pl_vendor_req(dev, 1, (u8) val, 0);
0070 }
0071
0072 static inline int
0073 pl_set_QuickLink_features(struct usbnet *dev, int val)
0074 {
0075     return pl_vendor_req(dev, 3, (u8) val, 0);
0076 }
0077
0078 static int pl_reset(struct usbnet *dev)
0079 {
0080     int status;
0081
0082     /* some units seem to need this reset, others reject it utterly.
0083      * FIXME be more like "naplink" or windows drivers.
0084      */
0085     status = pl_set_QuickLink_features(dev,
0086         PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
0087     if (status != 0 && netif_msg_probe(dev))
0088         netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
0089     return 0;
0090 }
0091
0092 static const struct driver_info prolific_info = {
0093     .description =  "Prolific PL-2301/PL-2302/PL-25A1/PL-27A1",
0094     .flags =    FLAG_POINTTOPOINT | FLAG_NO_SETINT,
0095         /* some PL-2302 versions seem to fail usb_set_interface() */
0096     .reset =    pl_reset,
0097 };
0098
0099
0100 /*-------------------------------------------------------------------------*/
0101
0102 /*
0103  * Proilific's name won't normally be on the cables, and
0104  * may not be on the device.
0105  */
0106
0107 static const struct usb_device_id   products [] = {
0108
0109 /* full speed cables */
0110 {
0111     USB_DEVICE(0x067b, 0x0000), // PL-2301
0112     .driver_info =  (unsigned long) &prolific_info,
0113 }, {
0114     USB_DEVICE(0x067b, 0x0001), // PL-2302
0115     .driver_info =  (unsigned long) &prolific_info,
0116 },
0117
0118 /* high speed cables */
0119 {
0120     USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
0121     .driver_info =  (unsigned long) &prolific_info,
0122 }, {
0123     USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
0124     .driver_info =  (unsigned long) &prolific_info,
0125 }, {
0126     USB_DEVICE(0x3923, 0x7825),     /* National Instruments USB
0127                      * Host-to-Host Cable
0128                      */
0129     .driver_info =  (unsigned long) &prolific_info,
0130
0131 },
0132
0133 /* super speed cables */
0134 {
0135     USB_DEVICE(0x067b, 0x27a1),     /* PL-27A1, no eeprom
0136                      * also: goobay Active USB 3.0
0137                      * Data Link,
0138                      * Unitek Y-3501
0139                      */
0140     .driver_info =  (unsigned long) &prolific_info,
0141 },
0142
0143     { },        // END
0144 };
0145 MODULE_DEVICE_TABLE(usb, products);
0146
0147 static struct usb_driver plusb_driver = {
0148     .name =     "plusb",
0149     .id_table = products,
0150     .probe =    usbnet_probe,
0151     .disconnect =   usbnet_disconnect,
0152     .suspend =  usbnet_suspend,
0153     .resume =   usbnet_resume,
0154     .disable_hub_initiated_lpm = 1,
0155 };
0156
0157 module_usb_driver(plusb_driver);
0158
0159 MODULE_AUTHOR("David Brownell");
0160 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver");
0161 MODULE_LICENSE("GPL");