linux/drivers/usb/gadget/ether.c
David Brownell 4e19f220d4 USB: RNDIS gadget, fix issues talking from PXA
The reworked Ethernet gadget has an RNDIS interop problem when used
with the CDC subset driver ... e.g. on PXA 2xx and 3xx hardware,
which currently has a hard time talking to MS-Windows hosts.

The issue is that Microsoft requires USB_CLASS_COMM.  Fix by tweaking
the CDC subset driver to not switch to USB_CLASS_VENDOR_SPEC if RNDIS
is used in some other device configuration.

[ UPDATED:  some "statements" were comma-terminated; fix that. ]

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Aric Blumer <aric@sdgsystems.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12 15:16:39 -07:00

395 lines
12 KiB
C

/*
* ether.c -- Ethernet gadget driver, with CDC and non-CDC options
*
* Copyright (C) 2003-2005,2008 David Brownell
* Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
* Copyright (C) 2008 Nokia Corporation
*
* 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 VERBOSE_DEBUG */
#include <linux/kernel.h>
#include <linux/utsname.h>
#include "u_ether.h"
/*
* Ethernet gadget driver -- with CDC and non-CDC options
* Builds on hardware support for a full duplex link.
*
* CDC Ethernet is the standard USB solution for sending Ethernet frames
* using USB. Real hardware tends to use the same framing protocol but look
* different for control features. This driver strongly prefers to use
* this USB-IF standard as its open-systems interoperability solution;
* most host side USB stacks (except from Microsoft) support it.
*
* This is sometimes called "CDC ECM" (Ethernet Control Model) to support
* TLA-soup. "CDC ACM" (Abstract Control Model) is for modems, and a new
* "CDC EEM" (Ethernet Emulation Model) is starting to spread.
*
* There's some hardware that can't talk CDC ECM. We make that hardware
* implement a "minimalist" vendor-agnostic CDC core: same framing, but
* link-level setup only requires activating the configuration. Only the
* endpoint descriptors, and product/vendor IDs, are relevant; no control
* operations are available. Linux supports it, but other host operating
* systems may not. (This is a subset of CDC Ethernet.)
*
* It turns out that if you add a few descriptors to that "CDC Subset",
* (Windows) host side drivers from MCCI can treat it as one submode of
* a proprietary scheme called "SAFE" ... without needing to know about
* specific product/vendor IDs. So we do that, making it easier to use
* those MS-Windows drivers. Those added descriptors make it resemble a
* CDC MDLM device, but they don't change device behavior at all. (See
* MCCI Engineering report 950198 "SAFE Networking Functions".)
*
* A third option is also in use. Rather than CDC Ethernet, or something
* simpler, Microsoft pushes their own approach: RNDIS. The published
* RNDIS specs are ambiguous and appear to be incomplete, and are also
* needlessly complex. They borrow more from CDC ACM than CDC ECM.
*/
#define DRIVER_DESC "Ethernet Gadget"
#define DRIVER_VERSION "Memorial Day 2008"
#ifdef CONFIG_USB_ETH_RNDIS
#define PREFIX "RNDIS/"
#else
#define PREFIX ""
#endif
/*
* This driver aims for interoperability by using CDC ECM unless
*
* can_support_ecm()
*
* returns false, in which case it supports the CDC Subset. By default,
* that returns true; most hardware has no problems with CDC ECM, that's
* a good default. Previous versions of this driver had no default; this
* version changes that, removing overhead for new controller support.
*
* IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
*/
static inline bool has_rndis(void)
{
#ifdef CONFIG_USB_ETH_RNDIS
return true;
#else
return false;
#endif
}
/*-------------------------------------------------------------------------*/
/*
* Kbuild is not very cooperative with respect to linking separately
* compiled library objects into one module. So for now we won't use
* separate compilation ... ensuring init/exit sections work to shrink
* the runtime footprint, and giving us at least some parts of what
* a "gcc --combine ... part1.c part2.c part3.c ... " build would.
*/
#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"
#include "f_ecm.c"
#include "f_subset.c"
#ifdef CONFIG_USB_ETH_RNDIS
#include "f_rndis.c"
#include "rndis.c"
#endif
#include "u_ether.c"
/*-------------------------------------------------------------------------*/
/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
* Instead: allocate your own, using normal USB-IF procedures.
*/
/* Thanks to NetChip Technologies for donating this product ID.
* It's for devices with only CDC Ethernet configurations.
*/
#define CDC_VENDOR_NUM 0x0525 /* NetChip */
#define CDC_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */
/* For hardware that can't talk CDC, we use the same vendor ID that
* ARM Linux has used for ethernet-over-usb, both with sa1100 and
* with pxa250. We're protocol-compatible, if the host-side drivers
* use the endpoint descriptors. bcdDevice (version) is nonzero, so
* drivers that need to hard-wire endpoint numbers have a hook.
*
* The protocol is a minimal subset of CDC Ether, which works on any bulk
* hardware that's not deeply broken ... even on hardware that can't talk
* RNDIS (like SA-1100, with no interrupt endpoint, or anything that
* doesn't handle control-OUT).
*/
#define SIMPLE_VENDOR_NUM 0x049f
#define SIMPLE_PRODUCT_NUM 0x505a
/* For hardware that can talk RNDIS and either of the above protocols,
* use this ID ... the windows INF files will know it. Unless it's
* used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
* the non-RNDIS configuration.
*/
#define RNDIS_VENDOR_NUM 0x0525 /* NetChip */
#define RNDIS_PRODUCT_NUM 0xa4a2 /* Ethernet/RNDIS Gadget */
/*-------------------------------------------------------------------------*/
static struct usb_device_descriptor device_desc = {
.bLength = sizeof device_desc,
.bDescriptorType = USB_DT_DEVICE,
.bcdUSB = cpu_to_le16 (0x0200),
.bDeviceClass = USB_CLASS_COMM,
.bDeviceSubClass = 0,
.bDeviceProtocol = 0,
/* .bMaxPacketSize0 = f(hardware) */
/* Vendor and product id defaults change according to what configs
* we support. (As does bNumConfigurations.) These values can
* also be overridden by module parameters.
*/
.idVendor = cpu_to_le16 (CDC_VENDOR_NUM),
.idProduct = cpu_to_le16 (CDC_PRODUCT_NUM),
/* .bcdDevice = f(hardware) */
/* .iManufacturer = DYNAMIC */
/* .iProduct = DYNAMIC */
/* NO SERIAL NUMBER */
.bNumConfigurations = 1,
};
static struct usb_otg_descriptor otg_descriptor = {
.bLength = sizeof otg_descriptor,
.bDescriptorType = USB_DT_OTG,
/* REVISIT SRP-only hardware is possible, although
* it would not be called "OTG" ...
*/
.bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
};
static const struct usb_descriptor_header *otg_desc[] = {
(struct usb_descriptor_header *) &otg_descriptor,
NULL,
};
/* string IDs are assigned dynamically */
#define STRING_MANUFACTURER_IDX 0
#define STRING_PRODUCT_IDX 1
static char manufacturer[50];
static struct usb_string strings_dev[] = {
[STRING_MANUFACTURER_IDX].s = manufacturer,
[STRING_PRODUCT_IDX].s = PREFIX DRIVER_DESC,
{ } /* end of list */
};
static struct usb_gadget_strings stringtab_dev = {
.language = 0x0409, /* en-us */
.strings = strings_dev,
};
static struct usb_gadget_strings *dev_strings[] = {
&stringtab_dev,
NULL,
};
static u8 hostaddr[ETH_ALEN];
/*-------------------------------------------------------------------------*/
/*
* We may not have an RNDIS configuration, but if we do it needs to be
* the first one present. That's to make Microsoft's drivers happy,
* and to follow DOCSIS 1.0 (cable modem standard).
*/
static int __init rndis_do_config(struct usb_configuration *c)
{
/* FIXME alloc iConfiguration string, set it in c->strings */
if (gadget_is_otg(c->cdev->gadget)) {
c->descriptors = otg_desc;
c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
}
return rndis_bind_config(c, hostaddr);
}
static struct usb_configuration rndis_config_driver = {
.label = "RNDIS",
.bind = rndis_do_config,
.bConfigurationValue = 2,
/* .iConfiguration = DYNAMIC */
.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
};
/*-------------------------------------------------------------------------*/
/*
* We _always_ have an ECM or CDC Subset configuration.
*/
static int __init eth_do_config(struct usb_configuration *c)
{
/* FIXME alloc iConfiguration string, set it in c->strings */
if (gadget_is_otg(c->cdev->gadget)) {
c->descriptors = otg_desc;
c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
}
if (can_support_ecm(c->cdev->gadget))
return ecm_bind_config(c, hostaddr);
else
return geth_bind_config(c, hostaddr);
}
static struct usb_configuration eth_config_driver = {
/* .label = f(hardware) */
.bind = eth_do_config,
.bConfigurationValue = 1,
/* .iConfiguration = DYNAMIC */
.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
};
/*-------------------------------------------------------------------------*/
static int __init eth_bind(struct usb_composite_dev *cdev)
{
int gcnum;
struct usb_gadget *gadget = cdev->gadget;
int status;
/* set up network link layer */
status = gether_setup(cdev->gadget, hostaddr);
if (status < 0)
return status;
/* set up main config label and device descriptor */
if (can_support_ecm(cdev->gadget)) {
/* ECM */
eth_config_driver.label = "CDC Ethernet (ECM)";
} else {
/* CDC Subset */
eth_config_driver.label = "CDC Subset/SAFE";
device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM);
device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM);
if (!has_rndis())
device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
}
if (has_rndis()) {
/* RNDIS plus ECM-or-Subset */
device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM);
device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM);
device_desc.bNumConfigurations = 2;
}
gcnum = usb_gadget_controller_number(gadget);
if (gcnum >= 0)
device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
else {
/* We assume that can_support_ecm() tells the truth;
* but if the controller isn't recognized at all then
* that assumption is a bit more likely to be wrong.
*/
dev_warn(&gadget->dev,
"controller '%s' not recognized; trying %s\n",
gadget->name,
eth_config_driver.label);
device_desc.bcdDevice =
cpu_to_le16(0x0300 | 0x0099);
}
/* Allocate string descriptor numbers ... note that string
* contents can be overridden by the composite_dev glue.
*/
/* device descriptor strings: manufacturer, product */
snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
init_utsname()->sysname, init_utsname()->release,
gadget->name);
status = usb_string_id(cdev);
if (status < 0)
goto fail;
strings_dev[STRING_MANUFACTURER_IDX].id = status;
device_desc.iManufacturer = status;
status = usb_string_id(cdev);
if (status < 0)
goto fail;
strings_dev[STRING_PRODUCT_IDX].id = status;
device_desc.iProduct = status;
/* register our configuration(s); RNDIS first, if it's used */
if (has_rndis()) {
status = usb_add_config(cdev, &rndis_config_driver);
if (status < 0)
goto fail;
}
status = usb_add_config(cdev, &eth_config_driver);
if (status < 0)
goto fail;
dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
DRIVER_DESC);
return 0;
fail:
gether_cleanup();
return status;
}
static int __exit eth_unbind(struct usb_composite_dev *cdev)
{
gether_cleanup();
return 0;
}
static struct usb_composite_driver eth_driver = {
.name = "g_ether",
.dev = &device_desc,
.strings = dev_strings,
.bind = eth_bind,
.unbind = __exit_p(eth_unbind),
};
MODULE_DESCRIPTION(PREFIX DRIVER_DESC);
MODULE_AUTHOR("David Brownell, Benedikt Spanger");
MODULE_LICENSE("GPL");
static int __init init(void)
{
return usb_composite_register(&eth_driver);
}
module_init(init);
static void __exit cleanup(void)
{
usb_composite_unregister(&eth_driver);
}
module_exit(cleanup);