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, see <http://www.gnu.org/licenses/>. 18 */ 19 20 // #define DEBUG // error path messages, extra info 21 // #define VERBOSE // more; success messages 22 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/netdevice.h> 26 #include <linux/etherdevice.h> 27 #include <linux/ethtool.h> 28 #include <linux/workqueue.h> 29 #include <linux/mii.h> 30 #include <linux/usb.h> 31 #include <linux/usb/usbnet.h> 32 #include <linux/gfp.h> 33 34 35 /* 36 * GeneSys GL620USB-A (www.genesyslogic.com.tw) 37 * 38 * ... should partially interop with the Win32 driver for this hardware. 39 * The GeneSys docs imply there's some NDIS issue motivating this framing. 40 * 41 * Some info from GeneSys: 42 * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. 43 * (Some cables, like the BAFO-100c, use the half duplex version.) 44 * - For the full duplex model, the low bit of the version code says 45 * which side is which ("left/right"). 46 * - For the half duplex type, a control/interrupt handshake settles 47 * the transfer direction. (That's disabled here, partially coded.) 48 * A control URB would block until other side writes an interrupt. 49 * 50 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> 51 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. 52 */ 53 54 // control msg write command 55 #define GENELINK_CONNECT_WRITE 0xF0 56 // interrupt pipe index 57 #define GENELINK_INTERRUPT_PIPE 0x03 58 // interrupt read buffer size 59 #define INTERRUPT_BUFSIZE 0x08 60 // interrupt pipe interval value 61 #define GENELINK_INTERRUPT_INTERVAL 0x10 62 // max transmit packet number per transmit 63 #define GL_MAX_TRANSMIT_PACKETS 32 64 // max packet length 65 #define GL_MAX_PACKET_LEN 1514 66 // max receive buffer size 67 #define GL_RCV_BUF_SIZE \ 68 (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) 69 70 struct gl_packet { 71 __le32 packet_length; 72 char packet_data [1]; 73 }; 74 75 struct gl_header { 76 __le32 packet_count; 77 struct gl_packet packets; 78 }; 79 80 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 81 { 82 struct gl_header *header; 83 struct gl_packet *packet; 84 struct sk_buff *gl_skb; 85 u32 size; 86 u32 count; 87 88 header = (struct gl_header *) skb->data; 89 90 // get the packet count of the received skb 91 count = le32_to_cpu(header->packet_count); 92 if (count > GL_MAX_TRANSMIT_PACKETS) { 93 netdev_dbg(dev->net, 94 "genelink: invalid received packet count %u\n", 95 count); 96 return 0; 97 } 98 99 // set the current packet pointer to the first packet 100 packet = &header->packets; 101 102 // decrement the length for the packet count size 4 bytes 103 skb_pull(skb, 4); 104 105 while (count > 1) { 106 // get the packet length 107 size = le32_to_cpu(packet->packet_length); 108 109 // this may be a broken packet 110 if (size > GL_MAX_PACKET_LEN) { 111 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 112 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 *)&packet->packet_data[size]; 128 count--; 129 130 // shift the data pointer to the next gl_packet 131 skb_pull(skb, size + 4); 132 } 133 134 // skip the packet length field 4 bytes 135 skb_pull(skb, 4); 136 137 if (skb->len > GL_MAX_PACKET_LEN) { 138 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 139 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 __le32 *packet_count; 153 __le32 *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_set_tail_pointer(skb, 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 = (__le32 *) 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_POINTTOPOINT | 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 .disable_hub_initiated_lpm = 1, 232 }; 233 234 module_usb_driver(gl620a_driver); 235 236 MODULE_AUTHOR("Jiun-Jie Huang"); 237 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables"); 238 MODULE_LICENSE("GPL"); 239 240