diff options
Diffstat (limited to 'drivers/net/usb/gl620a.c')
| -rw-r--r-- | drivers/net/usb/gl620a.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/net/usb/gl620a.c b/drivers/net/usb/gl620a.c new file mode 100644 index 0000000000..46af78caf4 --- /dev/null +++ b/drivers/net/usb/gl620a.c @@ -0,0 +1,229 @@ +// 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[]; +}; + +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"); + |