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
  50 /*
  51  * Bits 0-4 can be used for software handshaking; they're set from
  52  * one end, cleared from the other, "read" with the interrupt byte.
  53  */
  54 #define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
  55 /* reserved bit -- rx ready (6) ? */
  56 #define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
  57 #define PL_RESET_OUT    (1<<4)          /* reset output pipe */
  58 #define PL_RESET_IN     (1<<3)          /* reset input pipe */
  59 #define PL_TX_C         (1<<2)          /* transmission complete */
  60 #define PL_TX_REQ       (1<<1)          /* transmission received */
  61 #define PL_PEER_E       (1<<0)          /* peer exists */
  62
  63 static inline int
  64 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
  65 {
  66         return usb_control_msg(dev->udev,
  67                 usb_rcvctrlpipe(dev->udev, 0),
  68                 req,
  69                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
  70                 val, index,
  71                 NULL, 0,
  72                 USB_CTRL_GET_TIMEOUT);
  73 }
  74
  75 static inline int
  76 pl_clear_QuickLink_features(struct usbnet *dev, int val)
  77 {
  78         return pl_vendor_req(dev, 1, (u8) val, 0);
  79 }
  80
  81 static inline int
  82 pl_set_QuickLink_features(struct usbnet *dev, int val)
  83 {
  84         return pl_vendor_req(dev, 3, (u8) val, 0);
  85 }
  86
  87 static int pl_reset(struct usbnet *dev)
  88 {
  89         /* some units seem to need this reset, others reject it utterly.
  90          * FIXME be more like "naplink" or windows drivers.
  91          */
  92         (void) pl_set_QuickLink_features(dev,
  93                 PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
  94         return 0;
  95 }
  96
  97 static const struct driver_info prolific_info = {
  98         .description =  "Prolific PL-2301/PL-2302",
  99         .flags =        FLAG_NO_SETINT,
 100                 /* some PL-2302 versions seem to fail usb_set_interface() */
 101         .reset =        pl_reset,
 102 };
 103
 104
 105 /*-------------------------------------------------------------------------*/
 106
 107 /*
 108  * Proilific's name won't normally be on the cables, and
 109  * may not be on the device.
 110  */
 111
 112 static const struct usb_device_id       products [] = {
 113
 114 {
 115         USB_DEVICE(0x067b, 0x0000),     // PL-2301
 116         .driver_info =  (unsigned long) &prolific_info,
 117 }, {
 118         USB_DEVICE(0x067b, 0x0001),     // PL-2302
 119         .driver_info =  (unsigned long) &prolific_info,
 120 },
 121
 122         { },            // END
 123 };
 124 MODULE_DEVICE_TABLE(usb, products);
 125
 126 static struct usb_driver plusb_driver = {
 127         .name =         "plusb",
 128         .id_table =     products,
 129         .probe =        usbnet_probe,
 130         .disconnect =   usbnet_disconnect,
 131         .suspend =      usbnet_suspend,
 132         .resume =       usbnet_resume,
 133 };
 134
 135 static int __init plusb_init(void)
 136 {
 137         return usb_register(&plusb_driver);
 138 }
 139 module_init(plusb_init);
 140
 141 static void __exit plusb_exit(void)
 142 {
 143         usb_deregister(&plusb_driver);
 144 }
 145 module_exit(plusb_exit);
 146
 147 MODULE_AUTHOR("David Brownell");
 148 MODULE_DESCRIPTION("Prolific PL-2301/2302 USB Host to Host Link Driver");
 149 MODULE_LICENSE("GPL");