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
  69 static inline int
  70 pl_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
  78 static inline int
  79 pl_clear_QuickLink_features(struct usbnet *dev, int val)
  80 {
  81         return pl_vendor_req(dev, 1, (u8) val, 0);
  82 }
  83
  84 static inline int
  85 pl_set_QuickLink_features(struct usbnet *dev, int val)
  86 {
  87         return pl_vendor_req(dev, 3, (u8) val, 0);
  88 }
  89
  90 static 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
 104 static 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
 119 static 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 };
 141 MODULE_DEVICE_TABLE(usb, products);
 142
 143 static 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
 153 module_usb_driver(plusb_driver);
 154
 155 MODULE_AUTHOR("David Brownell");
 156 MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
 157 MODULE_LICENSE("GPL");