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/config.h>
  25 #include <linux/module.h>
  26 #include <linux/sched.h>
  27 #include <linux/init.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/etherdevice.h>
  30 #include <linux/ethtool.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/mii.h>
  33 #include <linux/usb.h>
  34
  35 #include "usbnet.h"
  36
  37
  38 /*
  39  * GeneSys GL620USB-A (www.genesyslogic.com.tw)
  40  *
  41  * ... should partially interop with the Win32 driver for this hardware.
  42  * The GeneSys docs imply there's some NDIS issue motivating this framing.
  43  *
  44  * Some info from GeneSys:
  45  *  - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
  46  *    (Some cables, like the BAFO-100c, use the half duplex version.)
  47  *  - For the full duplex model, the low bit of the version code says
  48  *    which side is which ("left/right").
  49  *  - For the half duplex type, a control/interrupt handshake settles
  50  *    the transfer direction.  (That's disabled here, partially coded.)
  51  *    A control URB would block until other side writes an interrupt.
  52  *
  53  * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
  54  * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
  55  */
  56
  57 // control msg write command
  58 #define GENELINK_CONNECT_WRITE                  0xF0
  59 // interrupt pipe index
  60 #define GENELINK_INTERRUPT_PIPE                 0x03
  61 // interrupt read buffer size
  62 #define INTERRUPT_BUFSIZE                       0x08
  63 // interrupt pipe interval value
  64 #define GENELINK_INTERRUPT_INTERVAL             0x10
  65 // max transmit packet number per transmit
  66 #define GL_MAX_TRANSMIT_PACKETS                 32
  67 // max packet length
  68 #define GL_MAX_PACKET_LEN                       1514
  69 // max receive buffer size
  70 #define GL_RCV_BUF_SIZE         \
  71         (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)
  72
  73 struct gl_packet {
  74         u32             packet_length;
  75         char            packet_data [1];
  76 };
  77
  78 struct gl_header {
  79         u32                     packet_count;
  80         struct gl_packet        packets;
  81 };
  82
  83 #ifdef  GENELINK_ACK
  84
  85 // FIXME:  this code is incomplete, not debugged; it doesn't
  86 // handle interrupts correctly; it should use the generic
  87 // status IRQ code (which didn't exist back in 2001).
  88
  89 struct gl_priv {
  90         struct urb      *irq_urb;
  91         char            irq_buf [INTERRUPT_BUFSIZE];
  92 };
  93
  94 static inline int gl_control_write(struct usbnet *dev, u8 request, u16 value)
  95 {
  96         int retval;
  97
  98         retval = usb_control_msg(dev->udev,
  99                       usb_sndctrlpipe(dev->udev, 0),
 100                       request,
 101                       USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 102                       value,
 103                       0,                        // index
 104                       0,                        // data buffer
 105                       0,                        // size
 106                       USB_CTRL_SET_TIMEOUT);
 107         return retval;
 108 }
 109
 110 static void gl_interrupt_complete(struct urb *urb, struct pt_regs *regs)
 111 {
 112         int status = urb->status;
 113
 114         switch (status) {
 115         case 0:
 116                 /* success */
 117                 break;
 118         case -ECONNRESET:
 119         case -ENOENT:
 120         case -ESHUTDOWN:
 121                 /* this urb is terminated, clean up */
 122                 dbg("%s - urb shutting down with status: %d",
 123                                 __FUNCTION__, status);
 124                 return;
 125         default:
 126                 dbg("%s - nonzero urb status received: %d",
 127                                 __FUNCTION__, urb->status);
 128         }
 129
 130         status = usb_submit_urb(urb, GFP_ATOMIC);
 131         if (status)
 132                 err("%s - usb_submit_urb failed with result %d",
 133                      __FUNCTION__, status);
 134 }
 135
 136 static int gl_interrupt_read(struct usbnet *dev)
 137 {
 138         struct gl_priv  *priv = dev->priv_data;
 139         int             retval;
 140
 141         // issue usb interrupt read
 142         if (priv && priv->irq_urb) {
 143                 // submit urb
 144                 if ((retval = usb_submit_urb(priv->irq_urb, GFP_KERNEL)) != 0)
 145                         dbg("gl_interrupt_read: submit fail - %X...", retval);
 146                 else
 147                         dbg("gl_interrupt_read: submit success...");
 148         }
 149
 150         return 0;
 151 }
 152
 153 // check whether another side is connected
 154 static int genelink_check_connect(struct usbnet *dev)
 155 {
 156         int                     retval;
 157
 158         dbg("genelink_check_connect...");
 159
 160         // detect whether another side is connected
 161         if ((retval = gl_control_write(dev, GENELINK_CONNECT_WRITE, 0)) != 0) {
 162                 dbg("%s: genelink_check_connect write fail - %X",
 163                         dev->net->name, retval);
 164                 return retval;
 165         }
 166
 167         // usb interrupt read to ack another side
 168         if ((retval = gl_interrupt_read(dev)) != 0) {
 169                 dbg("%s: genelink_check_connect read fail - %X",
 170                         dev->net->name, retval);
 171                 return retval;
 172         }
 173
 174         dbg("%s: genelink_check_connect read success", dev->net->name);
 175         return 0;
 176 }
 177
 178 // allocate and initialize the private data for genelink
 179 static int genelink_init(struct usbnet *dev)
 180 {
 181         struct gl_priv *priv;
 182
 183         // allocate the private data structure
 184         if ((priv = kmalloc(sizeof *priv, GFP_KERNEL)) == 0) {
 185                 dbg("%s: cannot allocate private data per device",
 186                         dev->net->name);
 187                 return -ENOMEM;
 188         }
 189
 190         // allocate irq urb
 191         if ((priv->irq_urb = usb_alloc_urb(0, GFP_KERNEL)) == 0) {
 192                 dbg("%s: cannot allocate private irq urb per device",
 193                         dev->net->name);
 194                 kfree(priv);
 195                 return -ENOMEM;
 196         }
 197
 198         // fill irq urb
 199         usb_fill_int_urb(priv->irq_urb, dev->udev,
 200                 usb_rcvintpipe(dev->udev, GENELINK_INTERRUPT_PIPE),
 201                 priv->irq_buf, INTERRUPT_BUFSIZE,
 202                 gl_interrupt_complete, 0,
 203                 GENELINK_INTERRUPT_INTERVAL);
 204
 205         // set private data pointer
 206         dev->priv_data = priv;
 207
 208         return 0;
 209 }
 210
 211 // release the private data
 212 static int genelink_free(struct usbnet *dev)
 213 {
 214         struct gl_priv  *priv = dev->priv_data;
 215
 216         if (!priv)
 217                 return 0;
 218
 219 // FIXME:  can't cancel here; it's synchronous, and
 220 // should have happened earlier in any case (interrupt
 221 // handling needs to be generic)
 222
 223         // cancel irq urb first
 224         usb_kill_urb(priv->irq_urb);
 225
 226         // free irq urb
 227         usb_free_urb(priv->irq_urb);
 228
 229         // free the private data structure
 230         kfree(priv);
 231
 232         return 0;
 233 }
 234
 235 #endif
 236
 237 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 238 {
 239         struct gl_header        *header;
 240         struct gl_packet        *packet;
 241         struct sk_buff          *gl_skb;
 242         u32                     size;
 243
 244         header = (struct gl_header *) skb->data;
 245
 246         // get the packet count of the received skb
 247         le32_to_cpus(&header->packet_count);
 248         if ((header->packet_count > GL_MAX_TRANSMIT_PACKETS)
 249                         || (header->packet_count < 0)) {
 250                 dbg("genelink: invalid received packet count %d",
 251                         header->packet_count);
 252                 return 0;
 253         }
 254
 255         // set the current packet pointer to the first packet
 256         packet = &header->packets;
 257
 258         // decrement the length for the packet count size 4 bytes
 259         skb_pull(skb, 4);
 260
 261         while (header->packet_count > 1) {
 262                 // get the packet length
 263                 size = le32_to_cpu(packet->packet_length);
 264
 265                 // this may be a broken packet
 266                 if (size > GL_MAX_PACKET_LEN) {
 267                         dbg("genelink: invalid rx length %d", size);
 268                         return 0;
 269                 }
 270
 271                 // allocate the skb for the individual packet
 272                 gl_skb = alloc_skb(size, GFP_ATOMIC);
 273                 if (gl_skb) {
 274
 275                         // copy the packet data to the new skb
 276                         memcpy(skb_put(gl_skb, size),
 277                                         packet->packet_data, size);
 278                         usbnet_skb_return(dev, gl_skb);
 279                 }
 280
 281                 // advance to the next packet
 282                 packet = (struct gl_packet *)
 283                         &packet->packet_data [size];
 284                 header->packet_count--;
 285
 286                 // shift the data pointer to the next gl_packet
 287                 skb_pull(skb, size + 4);
 288         }
 289
 290         // skip the packet length field 4 bytes
 291         skb_pull(skb, 4);
 292
 293         if (skb->len > GL_MAX_PACKET_LEN) {
 294                 dbg("genelink: invalid rx length %d", skb->len);
 295                 return 0;
 296         }
 297         return 1;
 298 }
 299
 300 static struct sk_buff *
 301 genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 302 {
 303         int     padlen;
 304         int     length = skb->len;
 305         int     headroom = skb_headroom(skb);
 306         int     tailroom = skb_tailroom(skb);
 307         u32     *packet_count;
 308         u32     *packet_len;
 309
 310         // FIXME:  magic numbers, bleech
 311         padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;
 312
 313         if ((!skb_cloned(skb))
 314                         && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
 315                 if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
 316                         skb->data = memmove(skb->head + (4 + 4*1),
 317                                              skb->data, skb->len);
 318                         skb->tail = skb->data + skb->len;
 319                 }
 320         } else {
 321                 struct sk_buff  *skb2;
 322                 skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags);
 323                 dev_kfree_skb_any(skb);
 324                 skb = skb2;
 325                 if (!skb)
 326                         return NULL;
 327         }
 328
 329         // attach the packet count to the header
 330         packet_count = (u32 *) skb_push(skb, (4 + 4*1));
 331         packet_len = packet_count + 1;
 332
 333         *packet_count = cpu_to_le32(1);
 334         *packet_len = cpu_to_le32(length);
 335
 336         // add padding byte
 337         if ((skb->len % dev->maxpacket) == 0)
 338                 skb_put(skb, 1);
 339
 340         return skb;
 341 }
 342
 343 static int genelink_bind(struct usbnet *dev, struct usb_interface *intf)
 344 {
 345         dev->hard_mtu = GL_RCV_BUF_SIZE;
 346         dev->net->hard_header_len += 4;
 347         dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in);
 348         dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out);
 349         return 0;
 350 }
 351
 352 static const struct driver_info genelink_info = {
 353         .description =  "Genesys GeneLink",
 354         .flags =        FLAG_FRAMING_GL | FLAG_NO_SETINT,
 355         .bind =         genelink_bind,
 356         .rx_fixup =     genelink_rx_fixup,
 357         .tx_fixup =     genelink_tx_fixup,
 358
 359         .in = 1, .out = 2,
 360
 361 #ifdef  GENELINK_ACK
 362         .check_connect =genelink_check_connect,
 363 #endif
 364 };
 365
 366 static const struct usb_device_id       products [] = {
 367
 368 {
 369         USB_DEVICE(0x05e3, 0x0502),     // GL620USB-A
 370         .driver_info =  (unsigned long) &genelink_info,
 371 },
 372         /* NOT: USB_DEVICE(0x05e3, 0x0501),     // GL620USB
 373          * that's half duplex, not currently supported
 374          */
 375         { },            // END
 376 };
 377 MODULE_DEVICE_TABLE(usb, products);
 378
 379 static struct usb_driver gl620a_driver = {
 380         .name =         "gl620a",
 381         .id_table =     products,
 382         .probe =        usbnet_probe,
 383         .disconnect =   usbnet_disconnect,
 384         .suspend =      usbnet_suspend,
 385         .resume =       usbnet_resume,
 386 };
 387
 388 static int __init usbnet_init(void)
 389 {
 390         return usb_register(&gl620a_driver);
 391 }
 392 module_init(usbnet_init);
 393
 394 static void __exit usbnet_exit(void)
 395 {
 396         usb_deregister(&gl620a_driver);
 397 }
 398 module_exit(usbnet_exit);
 399
 400 MODULE_AUTHOR("Jiun-Jie Huang");
 401 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
 402 MODULE_LICENSE("GPL");
 403