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_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 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 73 pl_set_QuickLink_features(struct usbnet *dev, int val) 74 { 75 return pl_vendor_req(dev, 3, (u8) val, 0); 76 } 77 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