mirror of https://gitee.com/openkylin/linux.git
382 lines
9.2 KiB
C
382 lines
9.2 KiB
C
/*
|
|
* USB CDC EEM network interface driver
|
|
* Copyright (C) 2009 Oberthur Technologies
|
|
* by Omar Laazimani, Olivier Condemine
|
|
*
|
|
* 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/ctype.h>
|
|
#include <linux/ethtool.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/mii.h>
|
|
#include <linux/usb.h>
|
|
#include <linux/crc32.h>
|
|
#include <linux/usb/cdc.h>
|
|
#include <linux/usb/usbnet.h>
|
|
|
|
|
|
/*
|
|
* This driver is an implementation of the CDC "Ethernet Emulation
|
|
* Model" (EEM) specification, which encapsulates Ethernet frames
|
|
* for transport over USB using a simpler USB device model than the
|
|
* previous CDC "Ethernet Control Model" (ECM, or "CDC Ethernet").
|
|
*
|
|
* For details, see www.usb.org/developers/devclass_docs/CDC_EEM10.pdf
|
|
*
|
|
* This version has been tested with GIGAntIC WuaoW SIM Smart Card on 2.6.24,
|
|
* 2.6.27 and 2.6.30rc2 kernel.
|
|
* It has also been validated on Openmoko Om 2008.12 (based on 2.6.24 kernel).
|
|
* build on 23-April-2009
|
|
*/
|
|
|
|
#define EEM_HEAD 2 /* 2 byte header */
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static void eem_linkcmd_complete(struct urb *urb)
|
|
{
|
|
dev_kfree_skb(urb->context);
|
|
usb_free_urb(urb);
|
|
}
|
|
|
|
static void eem_linkcmd(struct usbnet *dev, struct sk_buff *skb)
|
|
{
|
|
struct urb *urb;
|
|
int status;
|
|
|
|
urb = usb_alloc_urb(0, GFP_ATOMIC);
|
|
if (!urb)
|
|
goto fail;
|
|
|
|
usb_fill_bulk_urb(urb, dev->udev, dev->out,
|
|
skb->data, skb->len, eem_linkcmd_complete, skb);
|
|
|
|
status = usb_submit_urb(urb, GFP_ATOMIC);
|
|
if (status) {
|
|
usb_free_urb(urb);
|
|
fail:
|
|
dev_kfree_skb(skb);
|
|
devwarn(dev, "link cmd failure\n");
|
|
return;
|
|
}
|
|
}
|
|
|
|
static int eem_bind(struct usbnet *dev, struct usb_interface *intf)
|
|
{
|
|
int status = 0;
|
|
|
|
status = usbnet_get_endpoints(dev, intf);
|
|
if (status < 0) {
|
|
usb_set_intfdata(intf, NULL);
|
|
usb_driver_release_interface(driver_of(intf), intf);
|
|
return status;
|
|
}
|
|
|
|
/* no jumbogram (16K) support for now */
|
|
|
|
dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* EEM permits packing multiple Ethernet frames into USB transfers
|
|
* (a "bundle"), but for TX we don't try to do that.
|
|
*/
|
|
static struct sk_buff *eem_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
|
|
gfp_t flags)
|
|
{
|
|
struct sk_buff *skb2 = NULL;
|
|
u16 len = skb->len;
|
|
u32 crc = 0;
|
|
int padlen = 0;
|
|
|
|
/* When ((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket) is
|
|
* zero, stick two bytes of zero length EEM packet on the end.
|
|
* Else the framework would add invalid single byte padding,
|
|
* since it can't know whether ZLPs will be handled right by
|
|
* all the relevant hardware and software.
|
|
*/
|
|
if (!((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket))
|
|
padlen += 2;
|
|
|
|
if (!skb_cloned(skb)) {
|
|
int headroom = skb_headroom(skb);
|
|
int tailroom = skb_tailroom(skb);
|
|
|
|
if ((tailroom >= ETH_FCS_LEN + padlen)
|
|
&& (headroom >= EEM_HEAD))
|
|
goto done;
|
|
|
|
if ((headroom + tailroom)
|
|
> (EEM_HEAD + ETH_FCS_LEN + padlen)) {
|
|
skb->data = memmove(skb->head +
|
|
EEM_HEAD,
|
|
skb->data,
|
|
skb->len);
|
|
skb_set_tail_pointer(skb, len);
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
skb2 = skb_copy_expand(skb, EEM_HEAD, ETH_FCS_LEN + padlen, flags);
|
|
if (!skb2)
|
|
return NULL;
|
|
|
|
dev_kfree_skb_any(skb);
|
|
skb = skb2;
|
|
|
|
done:
|
|
/* we don't use the "no Ethernet CRC" option */
|
|
crc = crc32_le(~0, skb->data, skb->len);
|
|
crc = ~crc;
|
|
|
|
put_unaligned_le32(crc, skb_put(skb, 4));
|
|
|
|
/* EEM packet header format:
|
|
* b0..13: length of ethernet frame
|
|
* b14: bmCRC (1 == valid Ethernet CRC)
|
|
* b15: bmType (0 == data)
|
|
*/
|
|
len = skb->len;
|
|
put_unaligned_le16(BIT(14) | len, skb_push(skb, 2));
|
|
|
|
/* Bundle a zero length EEM packet if needed */
|
|
if (padlen)
|
|
put_unaligned_le16(0, skb_put(skb, 2));
|
|
|
|
return skb;
|
|
}
|
|
|
|
static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
|
|
{
|
|
/*
|
|
* Our task here is to strip off framing, leaving skb with one
|
|
* data frame for the usbnet framework code to process. But we
|
|
* may have received multiple EEM payloads, or command payloads.
|
|
* So we must process _everything_ as if it's a header, except
|
|
* maybe the last data payload
|
|
*
|
|
* REVISIT the framework needs updating so that when we consume
|
|
* all payloads (the last or only message was a command, or a
|
|
* zero length EEM packet) that is not accounted as an rx_error.
|
|
*/
|
|
do {
|
|
struct sk_buff *skb2 = NULL;
|
|
u16 header;
|
|
u16 len = 0;
|
|
|
|
/* incomplete EEM header? */
|
|
if (skb->len < EEM_HEAD)
|
|
return 0;
|
|
|
|
/*
|
|
* EEM packet header format:
|
|
* b0..14: EEM type dependant (Data or Command)
|
|
* b15: bmType
|
|
*/
|
|
header = get_unaligned_le16(skb->data);
|
|
skb_pull(skb, EEM_HEAD);
|
|
|
|
/*
|
|
* The bmType bit helps to denote when EEM
|
|
* packet is data or command :
|
|
* bmType = 0 : EEM data payload
|
|
* bmType = 1 : EEM (link) command
|
|
*/
|
|
if (header & BIT(15)) {
|
|
u16 bmEEMCmd;
|
|
|
|
/*
|
|
* EEM (link) command packet:
|
|
* b0..10: bmEEMCmdParam
|
|
* b11..13: bmEEMCmd
|
|
* b14: bmReserved (must be 0)
|
|
* b15: 1 (EEM command)
|
|
*/
|
|
if (header & BIT(14)) {
|
|
devdbg(dev, "reserved command %04x\n", header);
|
|
continue;
|
|
}
|
|
|
|
bmEEMCmd = (header >> 11) & 0x7;
|
|
switch (bmEEMCmd) {
|
|
|
|
/* Responding to echo requests is mandatory. */
|
|
case 0: /* Echo command */
|
|
len = header & 0x7FF;
|
|
|
|
/* bogus command? */
|
|
if (skb->len < len)
|
|
return 0;
|
|
|
|
skb2 = skb_clone(skb, GFP_ATOMIC);
|
|
if (unlikely(!skb2))
|
|
goto next;
|
|
skb_trim(skb2, len);
|
|
put_unaligned_le16(BIT(15) | (1 << 11) | len,
|
|
skb_push(skb2, 2));
|
|
eem_linkcmd(dev, skb2);
|
|
break;
|
|
|
|
/*
|
|
* Host may choose to ignore hints.
|
|
* - suspend: peripheral ready to suspend
|
|
* - response: suggest N millisec polling
|
|
* - response complete: suggest N sec polling
|
|
*/
|
|
case 2: /* Suspend hint */
|
|
case 3: /* Response hint */
|
|
case 4: /* Response complete hint */
|
|
continue;
|
|
|
|
/*
|
|
* Hosts should never receive host-to-peripheral
|
|
* or reserved command codes; or responses to an
|
|
* echo command we didn't send.
|
|
*/
|
|
case 1: /* Echo response */
|
|
case 5: /* Tickle */
|
|
default: /* reserved */
|
|
devwarn(dev, "unexpected link command %d\n",
|
|
bmEEMCmd);
|
|
continue;
|
|
}
|
|
|
|
} else {
|
|
u32 crc, crc2;
|
|
int is_last;
|
|
|
|
/* zero length EEM packet? */
|
|
if (header == 0)
|
|
continue;
|
|
|
|
/*
|
|
* EEM data packet header :
|
|
* b0..13: length of ethernet frame
|
|
* b14: bmCRC
|
|
* b15: 0 (EEM data)
|
|
*/
|
|
len = header & 0x3FFF;
|
|
|
|
/* bogus EEM payload? */
|
|
if (skb->len < len)
|
|
return 0;
|
|
|
|
/* bogus ethernet frame? */
|
|
if (len < (ETH_HLEN + ETH_FCS_LEN))
|
|
goto next;
|
|
|
|
/*
|
|
* Treat the last payload differently: framework
|
|
* code expects our "fixup" to have stripped off
|
|
* headers, so "skb" is a data packet (or error).
|
|
* Else if it's not the last payload, keep "skb"
|
|
* for further processing.
|
|
*/
|
|
is_last = (len == skb->len);
|
|
if (is_last)
|
|
skb2 = skb;
|
|
else {
|
|
skb2 = skb_clone(skb, GFP_ATOMIC);
|
|
if (unlikely(!skb2))
|
|
return 0;
|
|
}
|
|
|
|
crc = get_unaligned_le32(skb2->data
|
|
+ len - ETH_FCS_LEN);
|
|
skb_trim(skb2, len - ETH_FCS_LEN);
|
|
|
|
/*
|
|
* The bmCRC helps to denote when the CRC field in
|
|
* the Ethernet frame contains a calculated CRC:
|
|
* bmCRC = 1 : CRC is calculated
|
|
* bmCRC = 0 : CRC = 0xDEADBEEF
|
|
*/
|
|
if (header & BIT(14))
|
|
crc2 = ~crc32_le(~0, skb2->data, skb2->len);
|
|
else
|
|
crc2 = 0xdeadbeef;
|
|
|
|
if (is_last)
|
|
return crc == crc2;
|
|
|
|
if (unlikely(crc != crc2)) {
|
|
dev->net->stats.rx_errors++;
|
|
dev_kfree_skb_any(skb2);
|
|
} else
|
|
usbnet_skb_return(dev, skb2);
|
|
}
|
|
|
|
next:
|
|
skb_pull(skb, len);
|
|
} while (skb->len);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static const struct driver_info eem_info = {
|
|
.description = "CDC EEM Device",
|
|
.flags = FLAG_ETHER,
|
|
.bind = eem_bind,
|
|
.rx_fixup = eem_rx_fixup,
|
|
.tx_fixup = eem_tx_fixup,
|
|
};
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static const struct usb_device_id products[] = {
|
|
{
|
|
USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_EEM,
|
|
USB_CDC_PROTO_EEM),
|
|
.driver_info = (unsigned long) &eem_info,
|
|
},
|
|
{
|
|
/* EMPTY == end of list */
|
|
},
|
|
};
|
|
MODULE_DEVICE_TABLE(usb, products);
|
|
|
|
static struct usb_driver eem_driver = {
|
|
.name = "cdc_eem",
|
|
.id_table = products,
|
|
.probe = usbnet_probe,
|
|
.disconnect = usbnet_disconnect,
|
|
.suspend = usbnet_suspend,
|
|
.resume = usbnet_resume,
|
|
};
|
|
|
|
|
|
static int __init eem_init(void)
|
|
{
|
|
return usb_register(&eem_driver);
|
|
}
|
|
module_init(eem_init);
|
|
|
|
static void __exit eem_exit(void)
|
|
{
|
|
usb_deregister(&eem_driver);
|
|
}
|
|
module_exit(eem_exit);
|
|
|
|
MODULE_AUTHOR("Omar Laazimani <omar.oberthur@gmail.com>");
|
|
MODULE_DESCRIPTION("USB CDC EEM");
|
|
MODULE_LICENSE("GPL");
|