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/netdevice.h> 25 #include <linux/etherdevice.h> 26 #include <linux/ethtool.h> 27 #include <linux/workqueue.h> 28 #include <linux/mii.h> 29 #include <linux/usb.h> 30 #include <linux/usb/usbnet.h> 31 #include <linux/gfp.h> 32 33 34 /* 35 * GeneSys GL620USB-A (www.genesyslogic.com.tw) 36 * 37 * ... should partially interop with the Win32 driver for this hardware. 38 * The GeneSys docs imply there's some NDIS issue motivating this framing. 39 * 40 * Some info from GeneSys: 41 * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. 42 * (Some cables, like the BAFO-100c, use the half duplex version.) 43 * - For the full duplex model, the low bit of the version code says 44 * which side is which ("left/right"). 45 * - For the half duplex type, a control/interrupt handshake settles 46 * the transfer direction. (That's disabled here, partially coded.) 47 * A control URB would block until other side writes an interrupt. 48 * 49 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> 50 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. 51 */ 52 53 // control msg write command 54 #define GENELINK_CONNECT_WRITE 0xF0 55 // interrupt pipe index 56 #define GENELINK_INTERRUPT_PIPE 0x03 57 // interrupt read buffer size 58 #define INTERRUPT_BUFSIZE 0x08 59 // interrupt pipe interval value 60 #define GENELINK_INTERRUPT_INTERVAL 0x10 61 // max transmit packet number per transmit 62 #define GL_MAX_TRANSMIT_PACKETS 32 63 // max packet length 64 #define GL_MAX_PACKET_LEN 1514 65 // max receive buffer size 66 #define GL_RCV_BUF_SIZE \ 67 (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) 68 69 struct gl_packet { 70 __le32 packet_length; 71 char packet_data [1]; 72 }; 73 74 struct gl_header { 75 __le32 packet_count; 76 struct gl_packet packets; 77 }; 78 79 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 80 { 81 struct gl_header *header; 82 struct gl_packet *packet; 83 struct sk_buff *gl_skb; 84 u32 size; 85 u32 count; 86 87 /* This check is no longer done by usbnet */ 88 if (skb->len < dev->net->hard_header_len) 89 return 0; 90 91 header = (struct gl_header *) skb->data; 92 93 // get the packet count of the received skb 94 count = le32_to_cpu(header->packet_count); 95 if (count > GL_MAX_TRANSMIT_PACKETS) { 96 netdev_dbg(dev->net, 97 "genelink: invalid received packet count %u\n", 98 count); 99 return 0; 100 } 101 102 // set the current packet pointer to the first packet 103 packet = &header->packets; 104 105 // decrement the length for the packet count size 4 bytes 106 skb_pull(skb, 4); 107 108 while (count > 1) { 109 // get the packet length 110 size = le32_to_cpu(packet->packet_length); 111 112 // this may be a broken packet 113 if (size > GL_MAX_PACKET_LEN) { 114 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 115 size); 116 return 0; 117 } 118 119 // allocate the skb for the individual packet 120 gl_skb = alloc_skb(size, GFP_ATOMIC); 121 if (gl_skb) { 122 123 // copy the packet data to the new skb 124 skb_put_data(gl_skb, packet->packet_data, size); 125 usbnet_skb_return(dev, gl_skb); 126 } 127 128 // advance to the next packet 129 packet = (struct gl_packet *)&packet->packet_data[size]; 130 count--; 131 132 // shift the data pointer to the next gl_packet 133 skb_pull(skb, size + 4); 134 } 135 136 // skip the packet length field 4 bytes 137 skb_pull(skb, 4); 138 139 if (skb->len > GL_MAX_PACKET_LEN) { 140 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 141 skb->len); 142 return 0; 143 } 144 return 1; 145 } 146 147 static struct sk_buff * 148 genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) 149 { 150 int padlen; 151 int length = skb->len; 152 int headroom = skb_headroom(skb); 153 int tailroom = skb_tailroom(skb); 154 __le32 *packet_count; 155 __le32 *packet_len; 156 157 // FIXME: magic numbers, bleech 158 padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1; 159 160 if ((!skb_cloned(skb)) 161 && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) { 162 if ((headroom < (4 + 4*1)) || (tailroom < padlen)) { 163 skb->data = memmove(skb->head + (4 + 4*1), 164 skb->data, skb->len); 165 skb_set_tail_pointer(skb, skb->len); 166 } 167 } else { 168 struct sk_buff *skb2; 169 skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags); 170 dev_kfree_skb_any(skb); 171 skb = skb2; 172 if (!skb) 173 return NULL; 174 } 175 176 // attach the packet count to the header 177 packet_count = skb_push(skb, (4 + 4 * 1)); 178 packet_len = packet_count + 1; 179 180 *packet_count = cpu_to_le32(1); 181 *packet_len = cpu_to_le32(length); 182 183 // add padding byte 184 if ((skb->len % dev->maxpacket) == 0) 185 skb_put(skb, 1); 186 187 return skb; 188 } 189 190 static int genelink_bind(struct usbnet *dev, struct usb_interface *intf) 191 { 192 dev->hard_mtu = GL_RCV_BUF_SIZE; 193 dev->net->hard_header_len += 4; 194 dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in); 195 dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out); 196 return 0; 197 } 198 199 static const struct driver_info genelink_info = { 200 .description = "Genesys GeneLink", 201 .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT, 202 .bind = genelink_bind, 203 .rx_fixup = genelink_rx_fixup, 204 .tx_fixup = genelink_tx_fixup, 205 206 .in = 1, .out = 2, 207 208 #ifdef GENELINK_ACK 209 .check_connect =genelink_check_connect, 210 #endif 211 }; 212 213 static const struct usb_device_id products [] = { 214 215 { 216 USB_DEVICE(0x05e3, 0x0502), // GL620USB-A 217 .driver_info = (unsigned long) &genelink_info, 218 }, 219 /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB 220 * that's half duplex, not currently supported 221 */ 222 { }, // END 223 }; 224 MODULE_DEVICE_TABLE(usb, products); 225 226 static struct usb_driver gl620a_driver = { 227 .name = "gl620a", 228 .id_table = products, 229 .probe = usbnet_probe, 230 .disconnect = usbnet_disconnect, 231 .suspend = usbnet_suspend, 232 .resume = usbnet_resume, 233 .disable_hub_initiated_lpm = 1, 234 }; 235 236 module_usb_driver(gl620a_driver); 237 238 MODULE_AUTHOR("Jiun-Jie Huang"); 239 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables"); 240 MODULE_LICENSE("GPL"); 241 242