1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * GeneSys GL620USB-A based links 4 * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw> 5 * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz> 6 */ 7 8 // #define DEBUG // error path messages, extra info 9 // #define VERBOSE // more; success messages 10 11 #include <linux/module.h> 12 #include <linux/netdevice.h> 13 #include <linux/etherdevice.h> 14 #include <linux/ethtool.h> 15 #include <linux/workqueue.h> 16 #include <linux/mii.h> 17 #include <linux/usb.h> 18 #include <linux/usb/usbnet.h> 19 #include <linux/gfp.h> 20 21 22 /* 23 * GeneSys GL620USB-A (www.genesyslogic.com.tw) 24 * 25 * ... should partially interop with the Win32 driver for this hardware. 26 * The GeneSys docs imply there's some NDIS issue motivating this framing. 27 * 28 * Some info from GeneSys: 29 * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. 30 * (Some cables, like the BAFO-100c, use the half duplex version.) 31 * - For the full duplex model, the low bit of the version code says 32 * which side is which ("left/right"). 33 * - For the half duplex type, a control/interrupt handshake settles 34 * the transfer direction. (That's disabled here, partially coded.) 35 * A control URB would block until other side writes an interrupt. 36 * 37 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> 38 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. 39 */ 40 41 // control msg write command 42 #define GENELINK_CONNECT_WRITE 0xF0 43 // interrupt pipe index 44 #define GENELINK_INTERRUPT_PIPE 0x03 45 // interrupt read buffer size 46 #define INTERRUPT_BUFSIZE 0x08 47 // interrupt pipe interval value 48 #define GENELINK_INTERRUPT_INTERVAL 0x10 49 // max transmit packet number per transmit 50 #define GL_MAX_TRANSMIT_PACKETS 32 51 // max packet length 52 #define GL_MAX_PACKET_LEN 1514 53 // max receive buffer size 54 #define GL_RCV_BUF_SIZE \ 55 (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) 56 57 struct gl_packet { 58 __le32 packet_length; 59 char packet_data [1]; 60 }; 61 62 struct gl_header { 63 __le32 packet_count; 64 struct gl_packet packets; 65 }; 66 genelink_rx_fixup(struct usbnet * dev,struct sk_buff * skb)67 static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 68 { 69 struct gl_header *header; 70 struct gl_packet *packet; 71 struct sk_buff *gl_skb; 72 u32 size; 73 u32 count; 74 75 /* This check is no longer done by usbnet */ 76 if (skb->len < dev->net->hard_header_len) 77 return 0; 78 79 header = (struct gl_header *) skb->data; 80 81 // get the packet count of the received skb 82 count = le32_to_cpu(header->packet_count); 83 if (count > GL_MAX_TRANSMIT_PACKETS) { 84 netdev_dbg(dev->net, 85 "genelink: invalid received packet count %u\n", 86 count); 87 return 0; 88 } 89 90 // set the current packet pointer to the first packet 91 packet = &header->packets; 92 93 // decrement the length for the packet count size 4 bytes 94 skb_pull(skb, 4); 95 96 while (count > 1) { 97 // get the packet length 98 size = le32_to_cpu(packet->packet_length); 99 100 // this may be a broken packet 101 if (size > GL_MAX_PACKET_LEN) { 102 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 103 size); 104 return 0; 105 } 106 107 // allocate the skb for the individual packet 108 gl_skb = alloc_skb(size, GFP_ATOMIC); 109 if (gl_skb) { 110 111 // copy the packet data to the new skb 112 skb_put_data(gl_skb, packet->packet_data, size); 113 usbnet_skb_return(dev, gl_skb); 114 } 115 116 // advance to the next packet 117 packet = (struct gl_packet *)&packet->packet_data[size]; 118 count--; 119 120 // shift the data pointer to the next gl_packet 121 skb_pull(skb, size + 4); 122 } 123 124 // skip the packet length field 4 bytes 125 skb_pull(skb, 4); 126 127 if (skb->len > GL_MAX_PACKET_LEN) { 128 netdev_dbg(dev->net, "genelink: invalid rx length %d\n", 129 skb->len); 130 return 0; 131 } 132 return 1; 133 } 134 135 static struct sk_buff * genelink_tx_fixup(struct usbnet * dev,struct sk_buff * skb,gfp_t flags)136 genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) 137 { 138 int padlen; 139 int length = skb->len; 140 int headroom = skb_headroom(skb); 141 int tailroom = skb_tailroom(skb); 142 __le32 *packet_count; 143 __le32 *packet_len; 144 145 // FIXME: magic numbers, bleech 146 padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1; 147 148 if ((!skb_cloned(skb)) 149 && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) { 150 if ((headroom < (4 + 4*1)) || (tailroom < padlen)) { 151 skb->data = memmove(skb->head + (4 + 4*1), 152 skb->data, skb->len); 153 skb_set_tail_pointer(skb, skb->len); 154 } 155 } else { 156 struct sk_buff *skb2; 157 skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags); 158 dev_kfree_skb_any(skb); 159 skb = skb2; 160 if (!skb) 161 return NULL; 162 } 163 164 // attach the packet count to the header 165 packet_count = skb_push(skb, (4 + 4 * 1)); 166 packet_len = packet_count + 1; 167 168 *packet_count = cpu_to_le32(1); 169 *packet_len = cpu_to_le32(length); 170 171 // add padding byte 172 if ((skb->len % dev->maxpacket) == 0) 173 skb_put(skb, 1); 174 175 return skb; 176 } 177 genelink_bind(struct usbnet * dev,struct usb_interface * intf)178 static int genelink_bind(struct usbnet *dev, struct usb_interface *intf) 179 { 180 dev->hard_mtu = GL_RCV_BUF_SIZE; 181 dev->net->hard_header_len += 4; 182 dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in); 183 dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out); 184 return 0; 185 } 186 187 static const struct driver_info genelink_info = { 188 .description = "Genesys GeneLink", 189 .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT, 190 .bind = genelink_bind, 191 .rx_fixup = genelink_rx_fixup, 192 .tx_fixup = genelink_tx_fixup, 193 194 .in = 1, .out = 2, 195 196 #ifdef GENELINK_ACK 197 .check_connect =genelink_check_connect, 198 #endif 199 }; 200 201 static const struct usb_device_id products [] = { 202 203 { 204 USB_DEVICE(0x05e3, 0x0502), // GL620USB-A 205 .driver_info = (unsigned long) &genelink_info, 206 }, 207 /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB 208 * that's half duplex, not currently supported 209 */ 210 { }, // END 211 }; 212 MODULE_DEVICE_TABLE(usb, products); 213 214 static struct usb_driver gl620a_driver = { 215 .name = "gl620a", 216 .id_table = products, 217 .probe = usbnet_probe, 218 .disconnect = usbnet_disconnect, 219 .suspend = usbnet_suspend, 220 .resume = usbnet_resume, 221 .disable_hub_initiated_lpm = 1, 222 }; 223 224 module_usb_driver(gl620a_driver); 225 226 MODULE_AUTHOR("Jiun-Jie Huang"); 227 MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables"); 228 MODULE_LICENSE("GPL"); 229 230