/*
* 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
}
/*-------------------------------------------------------------------------*/
/* 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 = __constant_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 = __constant_cpu_to_le16 (CDC_VENDOR_NUM),
.idProduct = __constant_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,
.bMaxPower = 1, /* 2 mA, minimal */
};
/*-------------------------------------------------------------------------*/
/*
* 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,
.bMaxPower = 1, /* 2 mA, minimal */
};
/*-------------------------------------------------------------------------*/
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),
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.
*/
WARNING(cdev, "controller '%s' not recognized; trying %s\n",
gadget->name,
eth_config_driver.label);
device_desc.bcdDevice =
__constant_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, ð_config_driver);
if (status < 0)
goto fail;
INFO(cdev, "%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(ð_driver);
}
module_init(init);
static void __exit cleanup(void)
{
usb_composite_unregister(ð_driver);
}
module_exit(cleanup);
