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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 // #define      DEBUG                   // error path messages, extra info
  21 // #define      VERBOSE                 // more; success messages
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/ethtool.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/mii.h>
  30 #include <linux/usb.h>
  31 #include <linux/usb/usbnet.h>
  32
  33
  34 /*
  35  * Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
  36  *
  37  * The protocol and handshaking used here should be bug-compatible
  38  * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
  39  *
  40  * HEADS UP:  this handshaking isn't all that robust.  This driver
  41  * gets confused easily if you unplug one end of the cable then
  42  * try to connect it again; you'll need to restart both ends. The
  43  * "naplink" software (used by some PlayStation/2 deveopers) does
  44  * the handshaking much better!   Also, sometimes this hardware
  45  * seems to get wedged under load.  Prolific docs are weak, and
  46  * don't identify differences between PL2301 and PL2302, much less
  47  * anything to explain the different PL2302 versions observed.
  48  *
  49  * NOTE:  pl2501 has several modes, including pl2301 and pl2302
  50  * compatibility.   Some docs suggest the difference between 2301
  51  * and 2302 is only to make MS-Windows use a different driver...
  52  *
  53  * pl25a1 glue based on patch from Tony Gibbs.  Prolific "docs" on
  54  * this chip are as usual incomplete about what control messages
  55  * are supported.
  56  */
  57
  58 /*
  59  * Bits 0-4 can be used for software handshaking; they're set from
  60  * one end, cleared from the other, "read" with the interrupt byte.
  61  */
  62 #define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
  63 /* reserved bit -- rx ready (6) ? */
  64 #define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
  65 #define PL_RESET_OUT    (1<<4)          /* reset output pipe */
  66 #define PL_RESET_IN     (1<<3)          /* reset input pipe */
  67 #define PL_TX_C         (1<<2)          /* transmission complete */
  68 #define PL_TX_REQ       (1<<1)          /* transmission received */
  69 #define PL_PEER_E       (1<<0)          /* peer exists */
  70
  71 static inline int
  72 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
  73 {
  74         return usb_control_msg(dev->udev,
  75                 usb_rcvctrlpipe(dev->udev, 0),
  76                 req,
  77                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
  78                 val, index,
  79                 NULL, 0,
  80                 USB_CTRL_GET_TIMEOUT);
  81 }
  82
  83 static inline int
  84 pl_clear_QuickLink_features(struct usbnet *dev, int val)
  85 {
  86         return pl_vendor_req(dev, 1, (u8) val, 0);
  87 }
  88
  89 static inline int
  90 pl_set_QuickLink_features(struct usbnet *dev, int val)
  91 {
  92         return pl_vendor_req(dev, 3, (u8) val, 0);
  93 }
  94
  95 static int pl_reset(struct usbnet *dev)
  96 {
  97         int status;
  98
  99         /* some units seem to need this reset, others reject it utterly.
 100          * FIXME be more like "naplink" or windows drivers.
 101          */
 102         status = pl_set_QuickLink_features(dev,
 103                 PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
 104         if (status != 0 && netif_msg_probe(dev))
 105                 netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
 106         return 0;
 107 }
 108
 109 static const struct driver_info prolific_info = {
 110         .description =  "Prolific PL-2301/PL-2302/PL-25A1",
 111         .flags =        FLAG_POINTTOPOINT | FLAG_NO_SETINT,
 112                 /* some PL-2302 versions seem to fail usb_set_interface() */
 113         .reset =        pl_reset,
 114 };
 115
 116
 117 /*-------------------------------------------------------------------------*/
 118
 119 /*
 120  * Proilific's name won't normally be on the cables, and
 121  * may not be on the device.
 122  */
 123
 124 static const struct usb_device_id       products [] = {
 125
 126 /* full speed cables */
 127 {
 128         USB_DEVICE(0x067b, 0x0000),     // PL-2301
 129         .driver_info =  (unsigned long) &prolific_info,
 130 }, {
 131         USB_DEVICE(0x067b, 0x0001),     // PL-2302
 132         .driver_info =  (unsigned long) &prolific_info,
 133 },
 134
 135 /* high speed cables */
 136 {
 137         USB_DEVICE(0x067b, 0x25a1),     /* PL-25A1, no eeprom */
 138         .driver_info =  (unsigned long) &prolific_info,
 139 }, {
 140         USB_DEVICE(0x050d, 0x258a),     /* Belkin F5U258/F5U279 (PL-25A1) */
 141         .driver_info =  (unsigned long) &prolific_info,
 142 },
 143
 144         { },            // END
 145 };
 146 MODULE_DEVICE_TABLE(usb, products);
 147
 148 static struct usb_driver plusb_driver = {
 149         .name =         "plusb",
 150         .id_table =     products,
 151         .probe =        usbnet_probe,
 152         .disconnect =   usbnet_disconnect,
 153         .suspend =      usbnet_suspend,
 154         .resume =       usbnet_resume,
 155 };
 156
 157 module_usb_driver(plusb_driver);
 158
 159 MODULE_AUTHOR("David Brownell");
 160 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
 161 MODULE_LICENSE("GPL");