diff options
Diffstat (limited to 'drivers/usb/gadget/ether.c')
| -rw-r--r-- | drivers/usb/gadget/ether.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c new file mode 100644 index 00000000..56c8ecae --- /dev/null +++ b/drivers/usb/gadget/ether.c @@ -0,0 +1,374 @@ +/* + * 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. + */ + +/* #define VERBOSE_DEBUG */ + +#include <linux/kernel.h> + +#if defined USB_ETH_RNDIS +# undef USB_ETH_RNDIS +#endif +#ifdef CONFIG_USB_ETH_RNDIS +# define USB_ETH_RNDIS y +#endif + +#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 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 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 "f_ecm.c" +#include "f_subset.c" +#ifdef USB_ETH_RNDIS +#include "f_rndis.c" +#include "rndis.c" +#endif +#include "f_eem.c" +#include "u_ether.c" + +/*-------------------------------------------------------------------------*/ +USB_GADGET_COMPOSITE_OPTIONS(); + +/* 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 */ + +/* For EEM gadgets */ +#define EEM_VENDOR_NUM 0x1d6b /* Linux Foundation */ +#define EEM_PRODUCT_NUM 0x0102 /* EEM 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, +}; + +static struct usb_string strings_dev[] = { + [USB_GADGET_MANUFACTURER_IDX].s = "", + [USB_GADGET_PRODUCT_IDX].s = PREFIX DRIVER_DESC, + [USB_GADGET_SERIAL_IDX].s = "", + { } /* 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]; +static struct eth_dev *the_dev; +/*-------------------------------------------------------------------------*/ + +/* + * 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, the_dev); +} + +static struct usb_configuration rndis_config_driver = { + .label = "RNDIS", + .bConfigurationValue = 2, + /* .iConfiguration = DYNAMIC */ + .bmAttributes = USB_CONFIG_ATT_SELFPOWER, +}; + +/*-------------------------------------------------------------------------*/ + +#ifdef CONFIG_USB_ETH_EEM +static bool use_eem = 1; +#else +static bool use_eem; +#endif +module_param(use_eem, bool, 0); +MODULE_PARM_DESC(use_eem, "use CDC EEM mode"); + +/* + * We _always_ have an ECM, CDC Subset, or EEM 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 (use_eem) + return eem_bind_config(c, the_dev); + else if (can_support_ecm(c->cdev->gadget)) + return ecm_bind_config(c, hostaddr, the_dev); + else + return geth_bind_config(c, hostaddr, the_dev); +} + +static struct usb_configuration eth_config_driver = { + /* .label = f(hardware) */ + .bConfigurationValue = 1, + /* .iConfiguration = DYNAMIC */ + .bmAttributes = USB_CONFIG_ATT_SELFPOWER, +}; + +/*-------------------------------------------------------------------------*/ + +static int __init eth_bind(struct usb_composite_dev *cdev) +{ + struct usb_gadget *gadget = cdev->gadget; + int status; + + /* set up network link layer */ + the_dev = gether_setup(cdev->gadget, hostaddr); + if (IS_ERR(the_dev)) + return PTR_ERR(the_dev); + + /* set up main config label and device descriptor */ + if (use_eem) { + /* EEM */ + eth_config_driver.label = "CDC Ethernet (EEM)"; + device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM); + device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM); + } else 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; + } + + /* Allocate string descriptor numbers ... note that string + * contents can be overridden by the composite_dev glue. + */ + + status = usb_string_ids_tab(cdev, strings_dev); + if (status < 0) + goto fail; + device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; + device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; + + /* register our configuration(s); RNDIS first, if it's used */ + if (has_rndis()) { + status = usb_add_config(cdev, &rndis_config_driver, + rndis_do_config); + if (status < 0) + goto fail; + } + + status = usb_add_config(cdev, ð_config_driver, eth_do_config); + if (status < 0) + goto fail; + + usb_composite_overwrite_options(cdev, &coverwrite); + dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n", + DRIVER_DESC); + + return 0; + +fail: + gether_cleanup(the_dev); + return status; +} + +static int __exit eth_unbind(struct usb_composite_dev *cdev) +{ + gether_cleanup(the_dev); + return 0; +} + +static __refdata struct usb_composite_driver eth_driver = { + .name = "g_ether", + .dev = &device_desc, + .strings = dev_strings, + .max_speed = USB_SPEED_SUPER, + .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_probe(ð_driver); +} +module_init(init); + +static void __exit cleanup(void) +{ + usb_composite_unregister(ð_driver); +} +module_exit(cleanup); |