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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * PL-2301/2302 USB host-to-host link cables4 * Copyright (C) 2000-2005 by David Brownell5 */6 7// #define DEBUG // error path messages, extra info8// #define VERBOSE // more; success messages9 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-compatible24 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.25 *26 * HEADS UP: this handshaking isn't all that robust. This driver27 * gets confused easily if you unplug one end of the cable then28 * try to connect it again; you'll need to restart both ends. The29 * "naplink" software (used by some PlayStation/2 developers) does30 * the handshaking much better! Also, sometimes this hardware31 * seems to get wedged under load. Prolific docs are weak, and32 * don't identify differences between PL2301 and PL2302, much less33 * anything to explain the different PL2302 versions observed.34 *35 * NOTE: pl2501 has several modes, including pl2301 and pl230236 * compatibility. Some docs suggest the difference between 230137 * and 2302 is only to make MS-Windows use a different driver...38 *39 * pl25a1 glue based on patch from Tony Gibbs. Prolific "docs" on40 * this chip are as usual incomplete about what control messages41 * are supported.42 */43 44/*45 * Bits 0-4 can be used for software handshaking; they're set from46 * 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 int58pl_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 int65pl_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, and96 * 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-2301104 .driver_info = (unsigned long) &prolific_info,105}, {106 USB_DEVICE(0x067b, 0x0001), // PL-2302107 .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 USB119 * Host-to-Host Cable120 */121 .driver_info = (unsigned long) &prolific_info,122 123},124 125/* super speed cables */126{127 USB_DEVICE(0x067b, 0x27a1), /* PL-27A1, no eeprom128 * also: goobay Active USB 3.0129 * Data Link,130 * Unitek Y-3501131 */132 .driver_info = (unsigned long) &prolific_info,133},134 135 { }, // END136};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