linux/drivers/net/usb/gl620a.c
Arnd Bergmann c261344d3c usbnet: use eth%d name for known ethernet devices
The documentation for the USB ethernet devices suggests that
only some devices are supposed to use usb0 as the network interface
name instead of eth0. The logic used there, and documented in
Kconfig for CDC is that eth0 will be used when the mac address
is a globally assigned one, but usb0 is used for the locally
managed range that is typically used on point-to-point links.

Unfortunately, this has caused a lot of pain on the smsc95xx
device that is used on the popular pandaboard without an
EEPROM to store the MAC address, which causes the driver to
call random_ether_address().

Obviously, there should be a proper MAC addressed assigned to
the device, and discussions are ongoing about how to solve
this, but this patch at least makes sure that the default
interface naming gets a little saner and matches what the
user can expect based on the documentation, including for
new devices.

The approach taken here is to flag whether a device might be a
point-to-point link with the new FLAG_POINTTOPOINT setting in
the usbnet driver_info. A driver can set both FLAG_POINTTOPOINT
and FLAG_ETHER if it is not sure (e.g. cdc_ether), or just one
of the two.  The usbnet framework only looks at the MAC address
for device naming if both flags are set, otherwise it trusts the
flag.

Signed-off-by: Arnd Bergmann <arnd.bergmann@linaro.org>
Tested-by: Andy Green <andy.green@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-01 20:12:02 -07:00

245 lines
6.5 KiB
C

/*
* 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>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.h>
#include <linux/init.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;
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) {
dbg("genelink: invalid received packet count %u", 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) {
dbg("genelink: invalid rx length %d", 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
memcpy(skb_put(gl_skb, size),
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) {
dbg("genelink: invalid rx length %d", 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 = (__le32 *) 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,
};
static int __init usbnet_init(void)
{
return usb_register(&gl620a_driver);
}
module_init(usbnet_init);
static void __exit usbnet_exit(void)
{
usb_deregister(&gl620a_driver);
}
module_exit(usbnet_exit);
MODULE_AUTHOR("Jiun-Jie Huang");
MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
MODULE_LICENSE("GPL");