drivers/usb/net/gl620a.c

   1 /*
   2  * GeneSys GL620USB-A based links
   3  * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
   4  * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 // #define      DEBUG                   // error path messages, extra info
  22 // #define      VERBOSE                 // more; success messages
  23
  24 #include <linux/module.h>
  25 #include <linux/sched.h>
  26 #include <linux/init.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/ethtool.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/mii.h>
  32 #include <linux/usb.h>
  33
  34 #include "usbnet.h"
  35
  36
  37 /*
  38  * GeneSys GL620USB-A (www.genesyslogic.com.tw)
  39  *
  40  * ... should partially interop with the Win32 driver for this hardware.
  41  * The GeneSys docs imply there's some NDIS issue motivating this framing.
  42  *
  43  * Some info from GeneSys:
  44  *  - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
  45  *    (Some cables, like the BAFO-100c, use the half duplex version.)
  46  *  - For the full duplex model, the low bit of the version code says
  47  *    which side is which ("left/right").
  48  *  - For the half duplex type, a control/interrupt handshake settles
  49  *    the transfer direction.  (That's disabled here, partially coded.)
  50  *    A control URB would block until other side writes an interrupt.
  51  *
  52  * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
  53  * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
  54  */
  55
  56 // control msg write command
  57 #define GENELINK_CONNECT_WRITE                  0xF0
  58 // interrupt pipe index
  59 #define GENELINK_INTERRUPT_PIPE                 0x03
  60 // interrupt read buffer size
  61 #define INTERRUPT_BUFSIZE                       0x08
  62 // interrupt pipe interval value
  63 #define GENELINK_INTERRUPT_INTERVAL             0x10
  64 // max transmit packet number per transmit
  65 #define GL_MAX_TRANSMIT_PACKETS                 32
  66 // max packet length
  67 #define GL_MAX_PACKET_LEN                       1514
  68 // max receive buffer size
  69 #define GL_RCV_BUF_SIZE         \
  70         (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)
  71
  72 struct gl_packet {
  73         u32             packet_length;
  74         char            packet_data [1];
  75 };
  76
  77 struct gl_header {
  78         u32                     packet_count;
  79         struct gl_packet        packets;
  80 };
  81
  82 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
  83 {
  84         struct gl_header        *header;
  85         struct gl_packet        *packet;
  86         struct sk_buff          *gl_skb;
  87         u32                     size;
  88
  89         header = (struct gl_header *) skb->data;
  90
  91         // get the packet count of the received skb
  92         le32_to_cpus(&header->packet_count);
  93         if ((header->packet_count > GL_MAX_TRANSMIT_PACKETS)
  94                         || (header->packet_count < 0)) {
  95                 dbg("genelink: invalid received packet count %d",
  96                         header->packet_count);
  97                 return 0;
  98         }
  99
 100         // set the current packet pointer to the first packet
 101         packet = &header->packets;
 102
 103         // decrement the length for the packet count size 4 bytes
 104         skb_pull(skb, 4);
 105
 106         while (header->packet_count > 1) {
 107                 // get the packet length
 108                 size = le32_to_cpu(packet->packet_length);
 109
 110                 // this may be a broken packet
 111                 if (size > GL_MAX_PACKET_LEN) {
 112                         dbg("genelink: invalid rx length %d", size);
 113                         return 0;
 114                 }
 115
 116                 // allocate the skb for the individual packet
 117                 gl_skb = alloc_skb(size, GFP_ATOMIC);
 118                 if (gl_skb) {
 119
 120                         // copy the packet data to the new skb
 121                         memcpy(skb_put(gl_skb, size),
 122                                         packet->packet_data, size);
 123                         usbnet_skb_return(dev, gl_skb);
 124                 }
 125
 126                 // advance to the next packet
 127                 packet = (struct gl_packet *)
 128                         &packet->packet_data [size];
 129                 header->packet_count--;
 130
 131                 // shift the data pointer to the next gl_packet
 132                 skb_pull(skb, size + 4);
 133         }
 134
 135         // skip the packet length field 4 bytes
 136         skb_pull(skb, 4);
 137
 138         if (skb->len > GL_MAX_PACKET_LEN) {
 139                 dbg("genelink: invalid rx length %d", skb->len);
 140                 return 0;
 141         }
 142         return 1;
 143 }
 144
 145 static struct sk_buff *
 146 genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 147 {
 148         int     padlen;
 149         int     length = skb->len;
 150         int     headroom = skb_headroom(skb);
 151         int     tailroom = skb_tailroom(skb);
 152         u32     *packet_count;
 153         u32     *packet_len;
 154
 155         // FIXME:  magic numbers, bleech
 156         padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;
 157
 158         if ((!skb_cloned(skb))
 159                         && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
 160                 if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
 161                         skb->data = memmove(skb->head + (4 + 4*1),
 162                                              skb->data, skb->len);
 163                         skb->tail = skb->data + skb->len;
 164                 }
 165         } else {
 166                 struct sk_buff  *skb2;
 167                 skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags);
 168                 dev_kfree_skb_any(skb);
 169                 skb = skb2;
 170                 if (!skb)
 171                         return NULL;
 172         }
 173
 174         // attach the packet count to the header
 175         packet_count = (u32 *) skb_push(skb, (4 + 4*1));
 176         packet_len = packet_count + 1;
 177
 178         *packet_count = cpu_to_le32(1);
 179         *packet_len = cpu_to_le32(length);
 180
 181         // add padding byte
 182         if ((skb->len % dev->maxpacket) == 0)
 183                 skb_put(skb, 1);
 184
 185         return skb;
 186 }
 187
 188 static int genelink_bind(struct usbnet *dev, struct usb_interface *intf)
 189 {
 190         dev->hard_mtu = GL_RCV_BUF_SIZE;
 191         dev->net->hard_header_len += 4;
 192         dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in);
 193         dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out);
 194         return 0;
 195 }
 196
 197 static const struct driver_info genelink_info = {
 198         .description =  "Genesys GeneLink",
 199         .flags =        FLAG_FRAMING_GL | FLAG_NO_SETINT,
 200         .bind =         genelink_bind,
 201         .rx_fixup =     genelink_rx_fixup,
 202         .tx_fixup =     genelink_tx_fixup,
 203
 204         .in = 1, .out = 2,
 205
 206 #ifdef  GENELINK_ACK
 207         .check_connect =genelink_check_connect,
 208 #endif
 209 };
 210
 211 static const struct usb_device_id       products [] = {
 212
 213 {
 214         USB_DEVICE(0x05e3, 0x0502),     // GL620USB-A
 215         .driver_info =  (unsigned long) &genelink_info,
 216 },
 217         /* NOT: USB_DEVICE(0x05e3, 0x0501),     // GL620USB
 218          * that's half duplex, not currently supported
 219          */
 220         { },            // END
 221 };
 222 MODULE_DEVICE_TABLE(usb, products);
 223
 224 static struct usb_driver gl620a_driver = {
 225         .name =         "gl620a",
 226         .id_table =     products,
 227         .probe =        usbnet_probe,
 228         .disconnect =   usbnet_disconnect,
 229         .suspend =      usbnet_suspend,
 230         .resume =       usbnet_resume,
 231 };
 232
 233 static int __init usbnet_init(void)
 234 {
 235         return usb_register(&gl620a_driver);
 236 }
 237 module_init(usbnet_init);
 238
 239 static void __exit usbnet_exit(void)
 240 {
 241         usb_deregister(&gl620a_driver);
 242 }
 243 module_exit(usbnet_exit);
 244
 245 MODULE_AUTHOR("Jiun-Jie Huang");
 246 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
 247 MODULE_LICENSE("GPL");
 248