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

   1/*
   2 * PL-2301/2302 USB host-to-host link cables
   3 * Copyright (C) 2000-2005 by David Brownell
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19// #define      DEBUG                   // error path messages, extra info
  20// #define      VERBOSE                 // more; success messages
  21
  22#include <linux/module.h>
  23#include <linux/netdevice.h>
  24#include <linux/etherdevice.h>
  25#include <linux/ethtool.h>
  26#include <linux/workqueue.h>
  27#include <linux/mii.h>
  28#include <linux/usb.h>
  29#include <linux/usb/usbnet.h>
  30
  31
  32/*
  33 * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/ 
  34 *
  35 * The protocol and handshaking used here should be bug-compatible
  36 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
  37 *
  38 * HEADS UP:  this handshaking isn't all that robust.  This driver
  39 * gets confused easily if you unplug one end of the cable then
  40 * try to connect it again; you'll need to restart both ends. The
  41 * "naplink" software (used by some PlayStation/2 deveopers) does
  42 * the handshaking much better!   Also, sometimes this hardware
  43 * seems to get wedged under load.  Prolific docs are weak, and
  44 * don't identify differences between PL2301 and PL2302, much less
  45 * anything to explain the different PL2302 versions observed.
  46 *
  47 * NOTE:  pl2501 has several modes, including pl2301 and pl2302
  48 * compatibility.   Some docs suggest the difference between 2301
  49 * and 2302 is only to make MS-Windows use a different driver...
  50 *
  51 * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
  52 * this chip are as usual incomplete about what control messages
  53 * are supported.
  54 */
  55
  56/*
  57 * Bits 0-4 can be used for software handshaking; they're set from
  58 * one end, cleared from the other, "read" with the interrupt byte.
  59 */
  60#define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
  61/* reserved bit -- rx ready (6) ? */
  62#define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
  63#define PL_RESET_OUT    (1<<4)          /* reset output pipe */
  64#define PL_RESET_IN     (1<<3)          /* reset input pipe */
  65#define PL_TX_C         (1<<2)          /* transmission complete */
  66#define PL_TX_REQ       (1<<1)          /* transmission received */
  67#define PL_PEER_E       (1<<0)          /* peer exists */
  68
  69static inline int
  70pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
  71{
  72        return usbnet_read_cmd(dev, req,
  73                                USB_DIR_IN | USB_TYPE_VENDOR |
  74                                USB_RECIP_DEVICE,
  75                                val, index, NULL, 0);
  76}
  77
  78static inline int
  79pl_clear_QuickLink_features(struct usbnet *dev, int val)
  80{
  81        return pl_vendor_req(dev, 1, (u8) val, 0);
  82}
  83
  84static inline int
  85pl_set_QuickLink_features(struct usbnet *dev, int val)
  86{
  87        return pl_vendor_req(dev, 3, (u8) val, 0);
  88}
  89
  90static int pl_reset(struct usbnet *dev)
  91{
  92        int status;
  93
  94        /* some units seem to need this reset, others reject it utterly.
  95         * FIXME be more like "naplink" or windows drivers.
  96         */
  97        status = pl_set_QuickLink_features(dev,
  98                PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
  99        if (status != 0 && netif_msg_probe(dev))
 100                netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
 101        return 0;
 102}
 103
 104static const struct driver_info prolific_info = {
 105        .description =  "Prolific PL-2301/PL-2302/PL-25A1",
 106        .flags =        FLAG_POINTTOPOINT | FLAG_NO_SETINT,
 107                /* some PL-2302 versions seem to fail usb_set_interface() */
 108        .reset =        pl_reset,
 109};
 110
 111
 112/*-------------------------------------------------------------------------*/
 113
 114/*
 115 * Proilific's name won't normally be on the cables, and
 116 * may not be on the device.
 117 */
 118
 119static const struct usb_device_id       products [] = {
 120
 121/* full speed cables */
 122{
 123        USB_DEVICE(0x067b, 0x0000),     // PL-2301
 124        .driver_info =  (unsigned long) &prolific_info,
 125}, {
 126        USB_DEVICE(0x067b, 0x0001),     // PL-2302
 127        .driver_info =  (unsigned long) &prolific_info,
 128},
 129
 130/* high speed cables */
 131{
 132        USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
 133        .driver_info =  (unsigned long) &prolific_info,
 134}, {
 135        USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
 136        .driver_info =  (unsigned long) &prolific_info,
 137},
 138
 139        { },            // END
 140};
 141MODULE_DEVICE_TABLE(usb, products);
 142
 143static struct usb_driver plusb_driver = {
 144        .name =         "plusb",
 145        .id_table =     products,
 146        .probe =        usbnet_probe,
 147        .disconnect =   usbnet_disconnect,
 148        .suspend =      usbnet_suspend,
 149        .resume =       usbnet_resume,
 150        .disable_hub_initiated_lpm = 1,
 151};
 152
 153module_usb_driver(plusb_driver);
 154
 155MODULE_AUTHOR("David Brownell");
 156MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
 157MODULE_LICENSE("GPL");
 158