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