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 57static inline int 58pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index) 59{ 60 return usbnet_write_cmd(dev, req, USB_TYPE_VENDOR | USB_RECIP_DEVICE, 61 val, index, NULL, 0); 62} 63 64static inline int 65pl_set_QuickLink_features(struct usbnet *dev, int val) 66{ 67 return pl_vendor_req(dev, 3, (u8) val, 0); 68} 69 70static 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 84static 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 99static 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}; 137MODULE_DEVICE_TABLE(usb, products); 138 139static 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 149module_usb_driver(plusb_driver); 150 151MODULE_AUTHOR("David Brownell"); 152MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver"); 153MODULE_LICENSE("GPL"); 154