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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * GeneSys GL620USB-A based links4 * 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 info9// #define VERBOSE // more; success messages10 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 says32 * which side is which ("left/right").33 * - For the half duplex type, a control/interrupt handshake settles34 * 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 command42#define GENELINK_CONNECT_WRITE 0xF043// interrupt pipe index44#define GENELINK_INTERRUPT_PIPE 0x0345// interrupt read buffer size46#define INTERRUPT_BUFSIZE 0x0847// interrupt pipe interval value48#define GENELINK_INTERRUPT_INTERVAL 0x1049// max transmit packet number per transmit50#define GL_MAX_TRANSMIT_PACKETS 3251// max packet length52#define GL_MAX_PACKET_LEN 151453// max receive buffer size54#define GL_RCV_BUF_SIZE \55 (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)56 57struct gl_packet {58 __le32 packet_length;59 char packet_data[];60};61 62struct gl_header {63 __le32 packet_count;64 struct gl_packet packets;65};66 67static 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 skb82 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 packet91 packet = &header->packets;92 93 // decrement the length for the packet count size 4 bytes94 skb_pull(skb, 4);95 96 while (count > 1) {97 // get the packet length98 size = le32_to_cpu(packet->packet_length);99 100 // this may be a broken packet101 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 packet108 gl_skb = alloc_skb(size, GFP_ATOMIC);109 if (gl_skb) {110 111 // copy the packet data to the new skb112 skb_put_data(gl_skb, packet->packet_data, size);113 usbnet_skb_return(dev, gl_skb);114 }115 116 // advance to the next packet117 packet = (struct gl_packet *)&packet->packet_data[size];118 count--;119 120 // shift the data pointer to the next gl_packet121 skb_pull(skb, size + 4);122 }123 124 // skip the packet length field 4 bytes125 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 135static struct sk_buff *136genelink_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, bleech146 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 header165 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 byte172 if ((skb->len % dev->maxpacket) == 0)173 skb_put(skb, 1);174 175 return skb;176}177 178static 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 187static 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_ACK197 .check_connect =genelink_check_connect,198#endif199};200 201static const struct usb_device_id products [] = {202 203{204 USB_DEVICE(0x05e3, 0x0502), // GL620USB-A205 .driver_info = (unsigned long) &genelink_info,206},207 /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB208 * that's half duplex, not currently supported209 */210 { }, // END211};212MODULE_DEVICE_TABLE(usb, products);213 214static 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 224module_usb_driver(gl620a_driver);225 226MODULE_AUTHOR("Jiun-Jie Huang");227MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");228MODULE_LICENSE("GPL");229 230