// SPDX-License-Identifier: GPL-2.0-or-later /* * GeneSys GL620USB-A based links * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw> * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz> */ // #define DEBUG // error path messages, extra info // #define VERBOSE // more; success messages #include <linux/module.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/ethtool.h> #include <linux/workqueue.h> #include <linux/mii.h> #include <linux/usb.h> #include <linux/usb/usbnet.h> #include <linux/gfp.h> /* * GeneSys GL620USB-A (www.genesyslogic.com.tw) * * ... should partially interop with the Win32 driver for this hardware. * The GeneSys docs imply there's some NDIS issue motivating this framing. * * Some info from GeneSys: * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. * (Some cables, like the BAFO-100c, use the half duplex version.) * - For the full duplex model, the low bit of the version code says * which side is which ("left/right"). * - For the half duplex type, a control/interrupt handshake settles * the transfer direction. (That's disabled here, partially coded.) * A control URB would block until other side writes an interrupt. * * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. */ // control msg write command #define GENELINK_CONNECT_WRITE 0xF0 // interrupt pipe index #define GENELINK_INTERRUPT_PIPE 0x03 // interrupt read buffer size #define INTERRUPT_BUFSIZE 0x08 // interrupt pipe interval value #define GENELINK_INTERRUPT_INTERVAL 0x10 // max transmit packet number per transmit #define GL_MAX_TRANSMIT_PACKETS 32 // max packet length #define GL_MAX_PACKET_LEN 1514 // max receive buffer size #define GL_RCV_BUF_SIZE \ (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) struct gl_packet { __le32 packet_length; char packet_data [1]; }; struct gl_header { __le32 packet_count; struct gl_packet packets; }; static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) { struct gl_header *header; struct gl_packet *packet; struct sk_buff *gl_skb; u32 size; u32 count; /* This check is no longer done by usbnet */ if (skb->len < dev->net->hard_header_len) return 0; header = (struct gl_header *) skb->data; // get the packet count of the received skb count = le32_to_cpu(header->packet_count); if (count > GL_MAX_TRANSMIT_PACKETS) { netdev_dbg(dev->net, "genelink: invalid received packet count %u\n", count); return 0; } // set the current packet pointer to the first packet packet = &header->packets; // decrement the length for the packet count size 4 bytes skb_pull(skb, 4); while (count > 1) { // get the packet length size = le32_to_cpu(packet->packet_length); // this may be a broken packet if (size > GL_MAX_PACKET_LEN) { netdev_dbg(dev->net, "genelink: invalid rx length %d\n", size); return 0; } // allocate the skb for the individual packet gl_skb = alloc_skb(size, GFP_ATOMIC); if (gl_skb) { // copy the packet data to the new skb skb_put_data(gl_skb, packet->packet_data, size); usbnet_skb_return(dev, gl_skb); } // advance to the next packet packet = (struct gl_packet *)&packet->packet_data[size]; count--; // shift the data pointer to the next gl_packet skb_pull(skb, size + 4); } // skip the packet length field 4 bytes skb_pull(skb, 4); if (skb->len > GL_MAX_PACKET_LEN) { netdev_dbg(dev->net, "genelink: invalid rx length %d\n", skb->len); return 0; } return 1; } static struct sk_buff * genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) { int padlen; int length = skb->len; int headroom = skb_headroom(skb); int tailroom = skb_tailroom(skb); __le32 *packet_count; __le32 *packet_len; // FIXME: magic numbers, bleech padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1; if ((!skb_cloned(skb)) && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) { if ((headroom < (4 + 4*1)) || (tailroom < padlen)) { skb->data = memmove(skb->head + (4 + 4*1), skb->data, skb->len); skb_set_tail_pointer(skb, skb->len); } } else { struct sk_buff *skb2; skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags); dev_kfree_skb_any(skb); skb = skb2; if (!skb) return NULL; } // attach the packet count to the header packet_count = skb_push(skb, (4 + 4 * 1)); packet_len = packet_count + 1; *packet_count = cpu_to_le32(1); *packet_len = cpu_to_le32(length); // add padding byte if ((skb->len % dev->maxpacket) == 0) skb_put(skb, 1); return skb; } static int genelink_bind(struct usbnet *dev, struct usb_interface *intf) { dev->hard_mtu = GL_RCV_BUF_SIZE; dev->net->hard_header_len += 4; dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in); dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out); return 0; } static const struct driver_info genelink_info = { .description = "Genesys GeneLink", .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT, .bind = genelink_bind, .rx_fixup = genelink_rx_fixup, .tx_fixup = genelink_tx_fixup, .in = 1, .out = 2, #ifdef GENELINK_ACK .check_connect =genelink_check_connect, #endif }; static const struct usb_device_id products [] = { { USB_DEVICE(0x05e3, 0x0502), // GL620USB-A .driver_info = (unsigned long) &genelink_info, }, /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB * that's half duplex, not currently supported */ { }, // END }; MODULE_DEVICE_TABLE(usb, products); static struct usb_driver gl620a_driver = { .name = "gl620a", .id_table = products, .probe = usbnet_probe, .disconnect = usbnet_disconnect, .suspend = usbnet_suspend, .resume = usbnet_resume, .disable_hub_initiated_lpm = 1, }; module_usb_driver(gl620a_driver); MODULE_AUTHOR("Jiun-Jie Huang"); MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables"); MODULE_LICENSE("GPL");