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/init.h> 26 #include <linux/netdevice.h> 27 #include <linux/etherdevice.h> 28 #include <linux/ethtool.h> 29 #include <linux/workqueue.h> 30 #include <linux/mii.h> 31 #include <linux/usb.h> 32 #include <linux/usb/usbnet.h> 33 #include <linux/gfp.h> 34 35 36 /* 37 * GeneSys GL620USB-A (www.genesyslogic.com.tw) 38 * 39 * ... should partially interop with the Win32 driver for this hardware. 40 * The GeneSys docs imply there's some NDIS issue motivating this framing. 41 * 42 * Some info from GeneSys: 43 * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. 44 * (Some cables, like the BAFO-100c, use the half duplex version.) 45 * - For the full duplex model, the low bit of the version code says 46 * which side is which ("left/right"). 47 * - For the half duplex type, a control/interrupt handshake settles 48 * the transfer direction. (That's disabled here, partially coded.) 49 * A control URB would block until other side writes an interrupt. 50 * 51 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> 52 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. 53 */ 54 55 // control msg write command 56 #define GENELINK_CONNECT_WRITE 0xF0 57 // interrupt pipe index 58 #define GENELINK_INTERRUPT_PIPE 0x03 59 // interrupt read buffer size 60 #define INTERRUPT_BUFSIZE 0x08 61 // interrupt pipe interval value 62 #define GENELINK_INTERRUPT_INTERVAL 0x10 63 // max transmit packet number per transmit 64 #define GL_MAX_TRANSMIT_PACKETS 32 65 // max packet length 66 #define GL_MAX_PACKET_LEN 1514 67 // max receive buffer size 68 #define GL_RCV_BUF_SIZE \ 69 (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) 70 71 struct gl_packet { 72 __le32 packet_length; 73 char packet_data [1]; 74 }; 75 76 struct gl_header { 77 __le32 packet_count; 78 struct gl_packet packets; 79 }; 80 81 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 82 { 83 struct gl_header *header; 84 struct gl_packet *packet; 85 struct sk_buff *gl_skb; 86 u32 size; 87 u32 count; 88 89 header = (struct gl_header *) skb->data; 90 91 // get the packet count of the received skb 92 count = le32_to_cpu(header->packet_count); 93 if (count > GL_MAX_TRANSMIT_PACKETS) { 94 netdev_dbg(dev->net, 95 "genelink: invalid received packet count %u\n", 96 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 (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 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 113 size); 114 return 0; 115 } 116 117 // allocate the skb for the individual packet 118 gl_skb = alloc_skb(size, GFP_ATOMIC); 119 if (gl_skb) { 120 121 // copy the packet data to the new skb 122 memcpy(skb_put(gl_skb, size), 123 packet->packet_data, size); 124 usbnet_skb_return(dev, gl_skb); 125 } 126 127 // advance to the next packet 128 packet = (struct gl_packet *)&packet->packet_data[size]; 129 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 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 140 skb->len); 141 return 0; 142 } 143 return 1; 144 } 145 146 static struct sk_buff * 147 genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) 148 { 149 int padlen; 150 int length = skb->len; 151 int headroom = skb_headroom(skb); 152 int tailroom = skb_tailroom(skb); 153 __le32 *packet_count; 154 __le32 *packet_len; 155 156 // FIXME: magic numbers, bleech 157 padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1; 158 159 if ((!skb_cloned(skb)) 160 && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) { 161 if ((headroom < (4 + 4*1)) || (tailroom < padlen)) { 162 skb->data = memmove(skb->head + (4 + 4*1), 163 skb->data, skb->len); 164 skb_set_tail_pointer(skb, skb->len); 165 } 166 } else { 167 struct sk_buff *skb2; 168 skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags); 169 dev_kfree_skb_any(skb); 170 skb = skb2; 171 if (!skb) 172 return NULL; 173 } 174 175 // attach the packet count to the header 176 packet_count = (__le32 *) skb_push(skb, (4 + 4*1)); 177 packet_len = packet_count + 1; 178 179 *packet_count = cpu_to_le32(1); 180 *packet_len = cpu_to_le32(length); 181 182 // add padding byte 183 if ((skb->len % dev->maxpacket) == 0) 184 skb_put(skb, 1); 185 186 return skb; 187 } 188 189 static int genelink_bind(struct usbnet *dev, struct usb_interface *intf) 190 { 191 dev->hard_mtu = GL_RCV_BUF_SIZE; 192 dev->net->hard_header_len += 4; 193 dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in); 194 dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out); 195 return 0; 196 } 197 198 static const struct driver_info genelink_info = { 199 .description = "Genesys GeneLink", 200 .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT, 201 .bind = genelink_bind, 202 .rx_fixup = genelink_rx_fixup, 203 .tx_fixup = genelink_tx_fixup, 204 205 .in = 1, .out = 2, 206 207 #ifdef GENELINK_ACK 208 .check_connect =genelink_check_connect, 209 #endif 210 }; 211 212 static const struct usb_device_id products [] = { 213 214 { 215 USB_DEVICE(0x05e3, 0x0502), // GL620USB-A 216 .driver_info = (unsigned long) &genelink_info, 217 }, 218 /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB 219 * that's half duplex, not currently supported 220 */ 221 { }, // END 222 }; 223 MODULE_DEVICE_TABLE(usb, products); 224 225 static struct usb_driver gl620a_driver = { 226 .name = "gl620a", 227 .id_table = products, 228 .probe = usbnet_probe, 229 .disconnect = usbnet_disconnect, 230 .suspend = usbnet_suspend, 231 .resume = usbnet_resume, 232 .disable_hub_initiated_lpm = 1, 233 }; 234 235 module_usb_driver(gl620a_driver); 236 237 MODULE_AUTHOR("Jiun-Jie Huang"); 238 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables"); 239 MODULE_LICENSE("GPL"); 240 241