/*
* Driver for USB ethernet port of Conexant CX82310-based ADSL routers
* Copyright (C) 2010 by Ondrej Zary
* some parts inspired by the cxacru driver
*
* 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
*/
#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>
enum cx82310_cmd {
CMD_START = 0x84, /* no effect? */
CMD_STOP = 0x85, /* no effect? */
CMD_GET_STATUS = 0x90, /* returns nothing? */
CMD_GET_MAC_ADDR = 0x91, /* read MAC address */
CMD_GET_LINK_STATUS = 0x92, /* not useful, link is always up */
CMD_ETHERNET_MODE = 0x99, /* unknown, needed during init */
};
enum cx82310_status {
STATUS_UNDEFINED,
STATUS_SUCCESS,
STATUS_ERROR,
STATUS_UNSUPPORTED,
STATUS_UNIMPLEMENTED,
STATUS_PARAMETER_ERROR,
STATUS_DBG_LOOPBACK,
};
#define CMD_PACKET_SIZE 64
/* first command after power on can take around 8 seconds */
#define CMD_TIMEOUT 15000
#define CMD_REPLY_RETRY 5
#define CX82310_MTU 1514
#define CMD_EP 0x01
/*
* execute control command
* - optionally send some data (command parameters)
* - optionally wait for the reply
* - optionally read some data from the reply
*/
static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
u8 *wdata, int wlen, u8 *rdata, int rlen)
{
int actual_len, retries, ret;
struct usb_device *udev = dev->udev;
u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* create command packet */
buf[0] = cmd;
if (wdata)
memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
/* send command packet */
ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
if (ret < 0) {
dev_err(&dev->udev->dev, "send command %#x: error %d\n",
cmd, ret);
goto end;
}
if (reply) {
/* wait for reply, retry if it's empty */
for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
buf, CMD_PACKET_SIZE, &actual_len,
CMD_TIMEOUT);
if (ret < 0) {
dev_err(&dev->udev->dev,
"reply receive error %d\n", ret);
goto end;
}
if (actual_len > 0)
break;
}
if (actual_len == 0) {
dev_err(&dev->udev->dev, "no reply to command %#x\n",
cmd);
ret = -EIO;
goto end;
}
if (buf[0] != cmd) {
dev_err(&dev->udev->dev,
"got reply to command %#x, expected: %#x\n",
buf[0], cmd);
ret = -EIO;
goto end;
}
if (buf[1] != STATUS_SUCCESS) {
dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
cmd, buf[1]);
ret = -EIO;
goto end;
}
if (rdata)
memcpy(rdata, buf + 4,
min_t(int, rlen, CMD_PACKET_SIZE - 4));
}
end:
kfree(buf);
return ret;
}
#define partial_len data[0] /* length of partial packet data */
#define partial_rem data[1] /* remaining (missing) data length */
#define partial_data data[2] /* partial packet data */
static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
{
int ret;
char buf[15];
struct usb_device *udev = dev->udev;
/* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
&& strcmp(buf, "USB NET CARD")) {
dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
return -ENODEV;
}
ret = usbnet_get_endpoints(dev, intf);
if (ret)
return ret;
/*
* this must not include ethernet header as the device can send partial
* packets with no header (and sometimes even empty URBs)
*/
dev->net->hard_header_len = 0;
/* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
dev->hard_mtu = CX82310_MTU + 2;
/* we can receive URBs up to 4KB from the device */
dev->rx_urb_size = 4096;
dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
if (!dev->partial_data)
return -ENOMEM;
/* enable ethernet mode (?) */
ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
if (ret) {
dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
ret);
goto err;
}
/* get the MAC address */
ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
dev->net->dev_addr, ETH_ALEN);
if (ret) {
dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
goto err;
}
/* start (does not seem to have any effect?) */
ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
if (ret)
goto err;
return 0;
err:
kfree((void *)dev->partial_data);
return ret;
}
static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
{
kfree((void *)dev->partial_data);
}
/*
* RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
* packet length at the beginning.
* The last packet might be incomplete (when it crosses the 4KB URB size),
* continuing in the next skb (without any headers).
* If a packet has odd length, there is one extra byte at the end (before next
* packet or at the end of the URB).
*/
static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
int len;
struct sk_buff *skb2;
/*
* If the last skb ended with an incomplete packet, this skb contains
* end of that packet at the beginning.
*/
if (dev->partial_rem) {
len = dev->partial_len + dev->partial_rem;
skb2 = alloc_skb(len, GFP_ATOMIC);
if (!skb2)
return 0;
skb_put(skb2, len);
memcpy(skb2->data, (void *)dev->partial_data,
dev->partial_len);
memcpy(skb2->data + dev->partial_len, skb->data,
dev->partial_rem);
usbnet_skb_return(dev, skb2);
skb_pull(skb, (dev->partial_rem + 1) & ~1);
dev->partial_rem = 0;
if (skb->len < 2)
return 1;
}
/* a skb can contain multiple packets */
while (skb->len > 1) {
/* first two bytes are packet length */
len = skb->data[0] | (skb->data[1] << 8);
skb_pull(skb, 2);
/* if last packet in the skb, let usbnet to process it */
if (len == skb->len || len + 1 == skb->len) {
skb_trim(skb, len);
break;
}
if (len > CX82310_MTU) {
dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
len);
return 0;
}
/* incomplete packet, save it for the next skb */
if (len > skb->len) {
dev->partial_len = skb->len;
dev->partial_rem = len - skb->len;
memcpy((void *)dev->partial_data, skb->data,
dev->partial_len);
skb_pull(skb, skb->len);
break;
}
skb2 = alloc_skb(len, GFP_ATOMIC);
if (!skb2)
return 0;
skb_put(skb2, len);
memcpy(skb2->data, skb->data, len);
/* process the packet */
usbnet_skb_return(dev, skb2);
skb_pull(skb, (len + 1) & ~1);
}
/* let usbnet process the last packet */
return 1;
}
/* TX is easy, just add 2 bytes of length at the beginning */
static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
gfp_t flags)
{
int len = skb->len;
if (skb_headroom(skb) < 2) {
struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
dev_kfree_skb_any(skb);
skb = skb2;
if (!skb)
return NULL;
}
skb_push(skb, 2);
skb->data[0] = len;
skb->data[1] = len >> 8;
return skb;
}
static const struct driver_info cx82310_info = {
.description = "Conexant CX82310 USB ethernet",
.flags = FLAG_ETHER,
.bind = cx82310_bind,
.unbind = cx82310_unbind,
.rx_fixup = cx82310_rx_fixup,
.tx_fixup = cx82310_tx_fixup,
};
static const struct usb_device_id products[] = {
{
USB_DEVICE_AND_INTERFACE_INFO(0x0572, 0xcb01, 0xff, 0, 0),
.driver_info = (unsigned long) &cx82310_info
},
{ },
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver cx82310_driver = {
.name = "cx82310_eth",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(cx82310_driver);
MODULE_AUTHOR("Ondrej Zary");
MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
MODULE_LICENSE("GPL");