LXR linux/drivers/net/usb/plusb.c

   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_read_cmd(dev, req,
  61                                USB_DIR_IN | USB_TYPE_VENDOR |
  62                                USB_RECIP_DEVICE,
  63                                val, index, NULL, 0);
  64}
  65
  66static inline int
  67pl_clear_QuickLink_features(struct usbnet *dev, int val)
  68{
  69        return pl_vendor_req(dev, 1, (u8) val, 0);
  70}
  71
  72static inline int
  73pl_set_QuickLink_features(struct usbnet *dev, int val)
  74{
  75        return pl_vendor_req(dev, 3, (u8) val, 0);
  76}
  77
  78static 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
  92static 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
 107static 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};
 145MODULE_DEVICE_TABLE(usb, products);
 146
 147static 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
 157module_usb_driver(plusb_driver);
 158
 159MODULE_AUTHOR("David Brownell");
 160MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver");
 161MODULE_LICENSE("GPL");
 162