ChangeSet 1.1136, 2003/09/24 11:55:54-07:00, david-b@pacbell.net [PATCH] USB: usb gadget support for 2.4 (4/5): ether This gadget driver provides Ethernet-style networking over USB. When used with more functional hardware (such as net2280), it implements the CDC Ethernet class, which is widely supported by non-Microsoft operating systems. (And since some cable modems talk CDC Ethernet, it can also talk to Windows; just not without installing a driver.) With hardware that has functional restrictions (like pxa2xx), it implements a "good parts" subset of the CDC spec, but doesn't advertise itself as conformant (subsets aren't). drivers/usb/gadget/ether.c | 1879 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 1879 insertions(+) diff -Nru a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/drivers/usb/gadget/ether.c Thu Sep 25 16:04:11 2003 @@ -0,0 +1,1879 @@ +/* + * ether.c -- Ethernet gadget driver, with CDC and non-CDC options + * + * Copyright (C) 2003 David Brownell + * + * 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 DEBUG 1 +// #define VERBOSE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include + +/*-------------------------------------------------------------------------*/ + +/* + * Ethernet gadget driver -- with CDC and non-CDC options + * + * 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. And Microsoft pushes their own approach + * (RNDIS) instead of the standard. + * + * There's some hardware that can't talk CDC. We make that hardware + * implement a "minimalist" vendor-agnostic CDC core: same framing, but + * link-level setup only requires activating the configuration. + */ + +#define DRIVER_DESC "Ethernet Gadget" +#define DRIVER_VERSION "Bastille Day 2003" + +static const char shortname [] = "ether"; +static const char driver_desc [] = DRIVER_DESC; + +#define MIN_PACKET sizeof(struct ethhdr) +#define MAX_PACKET ETH_DATA_LEN /* biggest packet we'll rx/tx */ +#define RX_EXTRA 20 /* guard against rx overflows */ + +/* FIXME allow high speed jumbograms */ + +/*-------------------------------------------------------------------------*/ + +#ifndef container_of +#define container_of list_entry +#endif + +/* 2.5 modified and renamed these */ + +#define work_struct tq_struct +#define INIT_WORK INIT_TQUEUE +#define schedule_work schedule_task +#define flush_scheduled_work flush_scheduled_tasks + +/*-------------------------------------------------------------------------*/ + +struct eth_dev { + spinlock_t lock; + struct usb_gadget *gadget; + struct usb_request *req; /* for control responses */ + + u8 config; + struct usb_ep *in_ep, *out_ep, *status_ep; + const struct usb_endpoint_descriptor + *in, *out, *status; + struct list_head tx_reqs, rx_reqs; + + struct net_device *net; + struct net_device_stats stats; + atomic_t tx_qlen; + + struct work_struct work; + unsigned long todo; +#define WORK_RX_MEMORY 0 +}; + +/*-------------------------------------------------------------------------*/ + +/* This driver keeps a variable number of requests queued, more at + * high speeds. (Numbers are just educated guesses, untuned.) + * Shrink the queue if memory is tight, or make it bigger to + * handle bigger traffic bursts between IRQs (assuming hw dma queues) + */ + +static unsigned qmult = 4; + +#define HS_FACTOR 5 + +#define qlen(gadget) \ + (qmult*((gadget->speed == USB_SPEED_HIGH) ? HS_FACTOR : 1)) + +/* defer IRQs on highspeed TX */ +#define TX_DELAY 8 + + +MODULE_PARM (qmult, "i"); +MODULE_PARM_DESC (qmult, "rx/tx buffering factor"); + +/*-------------------------------------------------------------------------*/ + +/* Thanks to NetChip Technologies for donating this product ID. + * + * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! + * Instead: allocate your own, using normal USB-IF procedures. + */ +#define DRIVER_VENDOR_NUM 0x0525 /* NetChip */ +#define DRIVER_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */ + +/*-------------------------------------------------------------------------*/ + +/* + * hardware-specific configuration, controlled by which device + * controller driver was configured. + * + * CHIP ... hardware identifier + * DRIVER_VERSION_NUM ... alerts the host side driver to differences + * EP0_MAXPACKET ... controls packetization of control requests + * EP_*_NAME ... which endpoints do we use for which purpose? + * EP_*_NUM ... numbers for them (often limited by hardware) + * HIGHSPEED ... define if ep0 and descriptors need high speed support + * MAX_USB_POWER ... define if we use other than 100 mA bus current + * SELFPOWER ... unless we can run on bus power, USB_CONFIG_ATT_SELFPOWER + * WAKEUP ... if hardware supports remote wakeup AND we will issue the + * usb_gadget_wakeup() call to initiate it, USB_CONFIG_ATT_WAKEUP + * + * hw_optimize(gadget) ... for any hardware tweaks we want to kick in + * before we enable our endpoints + * + * add other defines for other portability issues, like hardware that + * for some reason doesn't handle full speed bulk maxpacket of 64. + */ + +#define DEV_CONFIG_VALUE 3 /* some hardware cares */ + +/* #undef on hardware that can't implement CDC */ +#define DEV_CONFIG_CDC + +/* + * NetChip 2280, PCI based. + * + * use DMA with fat fifos for all data traffic, PIO for the status channel + * where its 64 byte maxpacket ceiling is no issue. + * + * performance note: only PIO needs per-usb-packet IRQs (ep0, ep-e, ep-f) + * otherwise IRQs are per-Ethernet-packet unless TX_DELAY and chaining help. + */ +#ifdef CONFIG_USB_ETH_NET2280 +#define CHIP "net2280" +#define DRIVER_VERSION_NUM 0x0111 +#define EP0_MAXPACKET 64 +static const char EP_OUT_NAME [] = "ep-a"; +#define EP_OUT_NUM 1 +static const char EP_IN_NAME [] = "ep-b"; +#define EP_IN_NUM 2 +static const char EP_STATUS_NAME [] = "ep-f"; +#define EP_STATUS_NUM 3 +#define HIGHSPEED +/* specific hardware configs could be bus-powered */ +#define SELFPOWER USB_CONFIG_ATT_SELFPOWER +/* supports remote wakeup, but this driver doesn't */ + +extern int net2280_set_fifo_mode (struct usb_gadget *gadget, int mode); + +static inline void hw_optimize (struct usb_gadget *gadget) +{ + /* we can have bigger ep-a/ep-b fifos (2KB each, 4 USB packets + * for highspeed bulk) because we're not using ep-c/ep-d. + */ + net2280_set_fifo_mode (gadget, 1); +} +#endif + +/* + * PXA-2xx UDC: widely used in second gen Linux-capable ARM PDAs + * and other products. + * + * multiple interfaces (or altsettings) aren't usable. so this hardware + * can't implement CDC, which needs both capabilities. + */ +#ifdef CONFIG_USB_ETH_PXA2XX +#undef DEV_CONFIG_CDC +#define CHIP "pxa2xx" +#define DRIVER_VERSION_NUM 0x0113 +#define EP0_MAXPACKET 16 +static const char EP_OUT_NAME [] = "ep2out-bulk"; +#define EP_OUT_NUM 2 +static const char EP_IN_NAME [] = "ep1in-bulk"; +#define EP_IN_NUM 1 +/* doesn't support bus-powered operation */ +#define SELFPOWER USB_CONFIG_ATT_SELFPOWER +/* supports remote wakeup, but this driver doesn't */ + +/* no hw optimizations to apply */ +#define hw_optimize(g) do {} while (0); +#endif + +/* + * SA-1100 UDC: widely used in first gen Linux-capable PDAs. + * + * can't have a notification endpoint, since there are only the two + * bulk-capable ones. the CDC spec allows that. + */ +#ifdef CONFIG_USB_ETH_SA1100 +#define CHIP "sa1100" +#define DRIVER_VERSION_NUM 0x0115 +#define EP0_MAXPACKET 8 +static const char EP_OUT_NAME [] = "ep1out-bulk"; +#define EP_OUT_NUM 1 +static const char EP_IN_NAME [] = "ep2in-bulk"; +#define EP_IN_NUM 2 +// EP_STATUS_NUM is undefined +/* doesn't support bus-powered operation */ +#define SELFPOWER USB_CONFIG_ATT_SELFPOWER +/* doesn't support remote wakeup? */ + +/* no hw optimizations to apply */ +#define hw_optimize(g) do {} while (0); +#endif + +/*-------------------------------------------------------------------------*/ + +#ifndef EP0_MAXPACKET +# error Configure some USB peripheral controller driver! +#endif + +/* We normally expect hardware that can talk CDC. That involves + * using multiple interfaces and altsettings, and maybe a status + * interrupt. Driver binding to be done according to USB-IF class, + * though you can use different VENDOR and PRODUCT numbers if you + * want (and they're officially assigned). + * + * 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. DRIVER_VERSION_NUM is nonzero, so + * drivers that need to hard-wire endpoint numbers have a hook. + */ +#ifdef DEV_CONFIG_CDC +#define DEV_CONFIG_CLASS USB_CLASS_COMM +#else +#define DEV_CONFIG_CLASS USB_CLASS_VENDOR_SPEC +#undef EP_STATUS_NUM +#undef DRIVER_VENDOR_NUM +#undef DRIVER_PRODUCT_NUM +#define DRIVER_VENDOR_NUM 0x049f +#define DRIVER_PRODUCT_NUM 0x505a +#endif /* CONFIG_CDC_ETHER */ + +/* power usage is config specific. + * hardware that supports remote wakeup defaults to disabling it. + */ + +#ifndef SELFPOWER +/* default: say we rely on bus power */ +#define SELFPOWER 0 +/* else: + * - SELFPOWER value must be USB_CONFIG_ATT_SELFPOWER + * - MAX_USB_POWER may be nonzero. + */ +#endif + +#ifndef MAX_USB_POWER +/* any hub supports this steady state bus power consumption */ +#define MAX_USB_POWER 100 /* mA */ +#endif + +#ifndef WAKEUP +/* default: this driver won't do remote wakeup */ +#define WAKEUP 0 +/* else value must be USB_CONFIG_ATT_WAKEUP */ +#endif + +/*-------------------------------------------------------------------------*/ + +#define xprintk(d,level,fmt,args...) \ + printk(level "%s %s: " fmt , shortname , (d)->gadget->dev.bus_id , \ + ## args) + +#ifdef DEBUG +#undef DEBUG +#define DEBUG(dev,fmt,args...) \ + xprintk(dev , KERN_DEBUG , fmt , ## args) +#else +#define DEBUG(dev,fmt,args...) \ + do { } while (0) +#endif /* DEBUG */ + +#ifdef VERBOSE +#define VDEBUG DEBUG +#else +#define VDEBUG(dev,fmt,args...) \ + do { } while (0) +#endif /* DEBUG */ + +#define ERROR(dev,fmt,args...) \ + xprintk(dev , KERN_ERR , fmt , ## args) +#define WARN(dev,fmt,args...) \ + xprintk(dev , KERN_WARNING , fmt , ## args) +#define INFO(dev,fmt,args...) \ + xprintk(dev , KERN_INFO , fmt , ## args) + +/*-------------------------------------------------------------------------*/ + +/* USB DRIVER HOOKUP (to the hardware driver, below us), mostly + * ep0 implementation: descriptors, config management, setup(). + * also optional class-specific notification interrupt transfer. + */ + +/* + * DESCRIPTORS ... most are static, but strings and (full) configuration + * descriptors are built on demand. Notice how most of the cdc descriptors + * aren't needed in the "minimalist" mode. + */ + +#define STRING_MANUFACTURER 1 +#define STRING_PRODUCT 2 +#define STRING_ETHADDR 3 +#define STRING_DATA 4 +#define STRING_CONTROL 5 + +#define USB_BUFSIZ 256 /* holds our biggest descriptor */ + +/* + * This device advertises one configuration. + */ +static const struct usb_device_descriptor +device_desc = { + .bLength = sizeof device_desc, + .bDescriptorType = USB_DT_DEVICE, + + .bcdUSB = __constant_cpu_to_le16 (0x0200), + + .bDeviceClass = DEV_CONFIG_CLASS, + .bDeviceSubClass = 0, + .bDeviceProtocol = 0, + .bMaxPacketSize0 = EP0_MAXPACKET, + + .idVendor = __constant_cpu_to_le16 (DRIVER_VENDOR_NUM), + .idProduct = __constant_cpu_to_le16 (DRIVER_PRODUCT_NUM), + .bcdDevice = __constant_cpu_to_le16 (DRIVER_VERSION_NUM), + .iManufacturer = STRING_MANUFACTURER, + .iProduct = STRING_PRODUCT, + .bNumConfigurations = 1, +}; + +static const struct usb_config_descriptor +eth_config = { + .bLength = sizeof eth_config, + .bDescriptorType = USB_DT_CONFIG, + + /* compute wTotalLength on the fly */ +#ifdef DEV_CONFIG_CDC + .bNumInterfaces = 2, +#else + .bNumInterfaces = 1, +#endif + .bConfigurationValue = DEV_CONFIG_VALUE, + .iConfiguration = STRING_PRODUCT, + .bmAttributes = USB_CONFIG_ATT_ONE | SELFPOWER | WAKEUP, + .bMaxPower = (MAX_USB_POWER + 1) / 2, +}; + +#ifdef DEV_CONFIG_CDC + +/* + * Compared to the "minimalist" non-CDC model, the CDC model adds + * three class descriptors, two interface descrioptors, and a status + * endpoint. Both have a "data" interface and two bulk endpoints. + * There are also differences in how control requests are handled. + */ + +/* master comm interface optionally has a status notification endpoint */ + +static const struct usb_interface_descriptor +control_intf = { + .bLength = sizeof control_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 0, +#ifdef EP_STATUS_NUM + .bNumEndpoints = 1, +#else + .bNumEndpoints = 0, +#endif + .bInterfaceClass = USB_CLASS_COMM, + .bInterfaceSubClass = 6, /* ethernet control model */ + .bInterfaceProtocol = 0, + .iInterface = STRING_CONTROL, +}; + +/* "Header Functional Descriptor" from CDC spec 5.2.3.1 */ +struct header_desc { + u8 bLength; + u8 bDescriptorType; + u8 bDescriptorSubType; + + u16 bcdCDC; +} __attribute__ ((packed)); + +static const struct header_desc header_desc = { + .bLength = sizeof header_desc, + .bDescriptorType = 0x24, + .bDescriptorSubType = 0, + + .bcdCDC = __constant_cpu_to_le16 (0x0110), +}; + +/* "Union Functional Descriptor" from CDC spec 5.2.3.X */ +struct union_desc { + u8 bLength; + u8 bDescriptorType; + u8 bDescriptorSubType; + + u8 bMasterInterface0; + u8 bSlaveInterface0; + /* ... and there could be other slave interfaces */ +} __attribute__ ((packed)); + +static const struct union_desc union_desc = { + .bLength = sizeof union_desc, + .bDescriptorType = 0x24, + .bDescriptorSubType = 6, + + .bMasterInterface0 = 0, /* index of control interface */ + .bSlaveInterface0 = 1, /* index of DATA interface */ +}; + +/* "Ethernet Networking Functional Descriptor" from CDC spec 5.2.3.16 */ +struct ether_desc { + u8 bLength; + u8 bDescriptorType; + u8 bDescriptorSubType; + + u8 iMACAddress; + u32 bmEthernetStatistics; + u16 wMaxSegmentSize; + u16 wNumberMCFilters; + u8 bNumberPowerFilters; +} __attribute__ ((packed)); + +static const struct ether_desc ether_desc = { + .bLength = sizeof ether_desc, + .bDescriptorType = 0x24, + .bDescriptorSubType = 0x0f, + + /* this descriptor actually adds value, surprise! */ + .iMACAddress = STRING_ETHADDR, + .bmEthernetStatistics = __constant_cpu_to_le32 (0), /* no statistics */ + .wMaxSegmentSize = __constant_cpu_to_le16 (MAX_PACKET + ETH_HLEN), + .wNumberMCFilters = __constant_cpu_to_le16 (0), + .bNumberPowerFilters = 0, +}; + +#ifdef EP_STATUS_NUM + +/* include the status endpoint if we can, even though it's optional. + * + * some drivers (like current Linux cdc-ether!) "need" it to exist even + * if they ignore the connect/disconnect notifications that real aether + * can provide. more advanced cdc configurations might want to support + * encapsulated commands (vendor-specific, using control-OUT). + */ + +#define LOG2_STATUS_INTERVAL_MSEC 6 +#define STATUS_BYTECOUNT 16 /* 8 byte header + data */ +static const struct usb_endpoint_descriptor +fs_status_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_STATUS_NUM | USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = __constant_cpu_to_le16 (STATUS_BYTECOUNT), + .bInterval = 1 << LOG2_STATUS_INTERVAL_MSEC, +}; +#endif + +/* the default data interface has no endpoints ... */ + +static const struct usb_interface_descriptor +data_nop_intf = { + .bLength = sizeof data_nop_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 1, + .bAlternateSetting = 0, + .bNumEndpoints = 0, + .bInterfaceClass = USB_CLASS_CDC_DATA, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + .iInterface = STRING_DATA, +}; + +/* ... but the "real" data interface has two full speed bulk endpoints */ + +static const struct usb_interface_descriptor +data_intf = { + .bLength = sizeof data_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 1, + .bAlternateSetting = 1, + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_CDC_DATA, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + .iInterface = STRING_DATA, +}; +#else + +/* + * "Minimalist" non-CDC option is a simple vendor-neutral model that most + * full speed controllers can handle: one interface, two bulk endpoints. + */ + +static const struct usb_interface_descriptor +data_intf = { + .bLength = sizeof data_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 0, + .bAlternateSetting = 0, + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + .iInterface = STRING_DATA, +}; + +#endif /* DEV_CONFIG_CDC */ + + +static const struct usb_endpoint_descriptor +fs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_IN_NUM | USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16 (64), +}; + +static const struct usb_endpoint_descriptor +fs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_OUT_NUM, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16 (64), +}; + +#ifdef HIGHSPEED + +/* + * usb 2.0 devices need to expose both high speed and full speed + * descriptors, unless they only run at full speed. + */ + +#ifdef EP_STATUS_NUM +static const struct usb_endpoint_descriptor +hs_status_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_STATUS_NUM | USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = __constant_cpu_to_le16 (STATUS_BYTECOUNT), + .bInterval = LOG2_STATUS_INTERVAL_MSEC + 3, +}; +#endif + +static const struct usb_endpoint_descriptor +hs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_IN_NUM | USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16 (512), + .bInterval = 1, +}; + +static const struct usb_endpoint_descriptor +hs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = EP_OUT_NUM, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16 (512), + .bInterval = 1, +}; + +static const struct usb_qualifier_descriptor +dev_qualifier = { + .bLength = sizeof dev_qualifier, + .bDescriptorType = USB_DT_DEVICE_QUALIFIER, + + .bcdUSB = __constant_cpu_to_le16 (0x0200), + .bDeviceClass = DEV_CONFIG_CLASS, + + /* assumes ep0 uses the same value for both speeds ... */ + .bMaxPacketSize0 = EP0_MAXPACKET, + + .bNumConfigurations = 1, +}; + +/* maxpacket and other transfer characteristics vary by speed. */ +#define ep_desc(g,hs,fs) (((g)->speed==USB_SPEED_HIGH)?(hs):(fs)) + +#else + +/* if there's no high speed support, maxpacket doesn't change. */ +#define ep_desc(g,hs,fs) fs + +#endif /* !HIGHSPEED */ + +/*-------------------------------------------------------------------------*/ + +/* descriptors that are built on-demand */ + +#ifdef DEV_CONFIG_CDC +/* address that the host will use ... usually assigned at random */ +static char ethaddr [2 * ETH_ALEN + 1]; +#endif + +/* static strings, in iso 8859/1 */ +static struct usb_string strings [] = { + { STRING_MANUFACTURER, UTS_SYSNAME " " UTS_RELEASE "/" CHIP, }, + { STRING_PRODUCT, driver_desc, }, +#ifdef DEV_CONFIG_CDC + { STRING_ETHADDR, ethaddr, }, + { STRING_CONTROL, "CDC Communications Control", }, +#endif + { STRING_DATA, "Ethernet Data", }, + { } /* end of list */ +}; + +static struct usb_gadget_strings stringtab = { + .language = 0x0409, /* en-us */ + .strings = strings, +}; + +/* + * one config, two interfaces: control, data. + * complications: class descriptors, and an altsetting. + */ +static int +config_buf (enum usb_device_speed speed, u8 *buf, u8 type, unsigned index) +{ + const unsigned config_len = USB_DT_CONFIG_SIZE +#ifdef DEV_CONFIG_CDC + + 2 * USB_DT_INTERFACE_SIZE + + sizeof header_desc + + sizeof union_desc + + sizeof ether_desc +#ifdef EP_STATUS_NUM + + USB_DT_ENDPOINT_SIZE +#endif +#endif /* DEV_CONFIG_CDC */ + + USB_DT_INTERFACE_SIZE + + 2 * USB_DT_ENDPOINT_SIZE; + +#ifdef HIGHSPEED + int hs; +#endif + /* a single configuration must always be index 0 */ + if (index > 0) + return -EINVAL; + if (config_len > USB_BUFSIZ) + return -EDOM; + + /* config (or other speed config) */ + memcpy (buf, ð_config, USB_DT_CONFIG_SIZE); + buf [1] = type; + ((struct usb_config_descriptor *) buf)->wTotalLength + = __constant_cpu_to_le16 (config_len); + buf += USB_DT_CONFIG_SIZE; +#ifdef HIGHSPEED + hs = (speed == USB_SPEED_HIGH); + if (type == USB_DT_OTHER_SPEED_CONFIG) + hs = !hs; +#endif + +#ifdef DEV_CONFIG_CDC + /* control interface, class descriptors, optional status endpoint */ + memcpy (buf, &control_intf, USB_DT_INTERFACE_SIZE); + buf += USB_DT_INTERFACE_SIZE; + + memcpy (buf, &header_desc, sizeof header_desc); + buf += sizeof header_desc; + memcpy (buf, &union_desc, sizeof union_desc); + buf += sizeof union_desc; + memcpy (buf, ðer_desc, sizeof ether_desc); + buf += sizeof ether_desc; + +#ifdef EP_STATUS_NUM +#ifdef HIGHSPEED + if (hs) + memcpy (buf, &hs_status_desc, USB_DT_ENDPOINT_SIZE); + else +#endif /* HIGHSPEED */ + memcpy (buf, &fs_status_desc, USB_DT_ENDPOINT_SIZE); + buf += USB_DT_ENDPOINT_SIZE; +#endif /* EP_STATUS_NUM */ + + /* default data altsetting has no endpoints */ + memcpy (buf, &data_nop_intf, USB_DT_INTERFACE_SIZE); + buf += USB_DT_INTERFACE_SIZE; +#endif /* DEV_CONFIG_CDC */ + + /* the "real" data interface has two endpoints */ + memcpy (buf, &data_intf, USB_DT_INTERFACE_SIZE); + buf += USB_DT_INTERFACE_SIZE; +#ifdef HIGHSPEED + if (hs) { + memcpy (buf, &hs_source_desc, USB_DT_ENDPOINT_SIZE); + buf += USB_DT_ENDPOINT_SIZE; + memcpy (buf, &hs_sink_desc, USB_DT_ENDPOINT_SIZE); + buf += USB_DT_ENDPOINT_SIZE; + } else +#endif + { + memcpy (buf, &fs_source_desc, USB_DT_ENDPOINT_SIZE); + buf += USB_DT_ENDPOINT_SIZE; + memcpy (buf, &fs_sink_desc, USB_DT_ENDPOINT_SIZE); + buf += USB_DT_ENDPOINT_SIZE; + } + + return config_len; +} + +/*-------------------------------------------------------------------------*/ + +static void eth_start (struct eth_dev *dev, int gfp_flags); +static int alloc_requests (struct eth_dev *dev, unsigned n, int gfp_flags); + +static int +set_ether_config (struct eth_dev *dev, int gfp_flags) +{ + int result = 0; + struct usb_ep *ep; + struct usb_gadget *gadget = dev->gadget; + + gadget_for_each_ep (ep, gadget) { + const struct usb_endpoint_descriptor *d; + +#ifdef DEV_CONFIG_CDC + /* With CDC, the host isn't allowed to use these two data + * endpoints in the default altsetting for the interface. + * so we don't activate them yet. + */ + + /* one endpoint writes data back IN to the host */ + if (strcmp (ep->name, EP_IN_NAME) == 0) { + d = ep_desc (gadget, &hs_source_desc, &fs_source_desc); + ep->driver_data = dev; + dev->in_ep = ep; + dev->in = d; + continue; + + /* one endpoint just reads OUT packets */ + } else if (strcmp (ep->name, EP_OUT_NAME) == 0) { + d = ep_desc (gadget, &hs_sink_desc, &fs_sink_desc); + ep->driver_data = dev; + dev->out_ep = ep; + dev->out = d; + continue; + } + +#ifdef EP_STATUS_NUM + /* optional status/notification endpoint */ + else if (strcmp (ep->name, EP_STATUS_NAME) == 0) { + d = ep_desc (gadget, &hs_status_desc, &fs_status_desc); + result = usb_ep_enable (ep, d); + if (result == 0) { + ep->driver_data = dev; + dev->status_ep = ep; + dev->status = d; + continue; + } + } +#endif + +#else /* !CONFIG_CDC_ETHER */ + + /* non-CDC is simpler: if the device is there, + * it's live with rx and tx endpoints. + */ + /* one endpoint writes data back IN to the host */ + if (strcmp (ep->name, EP_IN_NAME) == 0) { + d = ep_desc (gadget, &hs_source_desc, &fs_source_desc); + result = usb_ep_enable (ep, d); + if (result == 0) { + ep->driver_data = dev; + dev->in_ep = ep; + dev->in = d; + continue; + } + + /* one endpoint just reads OUT packets */ + } else if (strcmp (ep->name, EP_OUT_NAME) == 0) { + d = ep_desc (gadget, &hs_sink_desc, &fs_sink_desc); + result = usb_ep_enable (ep, d); + if (result == 0) { + ep->driver_data = dev; + dev->out_ep = ep; + dev->out = d; + continue; + } + } + +#endif /* !CONFIG_CDC_ETHER */ + + /* ignore any other endpoints */ + else + continue; + + /* stop on error */ + ERROR (dev, "can't enable %s, result %d\n", ep->name, result); + break; + } + if (!result && (!dev->in_ep || !dev->out_ep)) + result = -ENODEV; + + if (result == 0) + result = alloc_requests (dev, qlen (gadget), gfp_flags); + +#ifndef DEV_CONFIG_CDC + if (result == 0) { + netif_carrier_on (dev->net); + if (netif_running (dev->net)) + eth_start (dev, GFP_ATOMIC); + } else { + (void) usb_ep_disable (dev->in_ep); + dev->in_ep = 0; + dev->in = 0; + (void) usb_ep_disable (dev->out_ep); + dev->out_ep = 0; + dev->out = 0; + } +#endif /* !CONFIG_CDC_ETHER */ + + if (result == 0) + DEBUG (dev, "qlen %d\n", qlen (gadget)); + + /* caller is responsible for cleanup on error */ + return result; +} + +static void eth_reset_config (struct eth_dev *dev) +{ + if (dev->config == 0) + return; + + DEBUG (dev, "%s\n", __FUNCTION__); + + netif_stop_queue (dev->net); + netif_carrier_off (dev->net); + + /* just disable endpoints, forcing completion of pending i/o. + * all our completion handlers free their requests in this case. + */ + if (dev->in_ep) { + usb_ep_disable (dev->in_ep); + dev->in_ep = 0; + } + if (dev->out_ep) { + usb_ep_disable (dev->out_ep); + dev->out_ep = 0; + } +#ifdef EP_STATUS_NUM + if (dev->status_ep) { + usb_ep_disable (dev->status_ep); + dev->status_ep = 0; + } +#endif + dev->config = 0; +} + +/* change our operational config. must agree with the code + * that returns config descriptors, and altsetting code. + */ +static int +eth_set_config (struct eth_dev *dev, unsigned number, int gfp_flags) +{ + int result = 0; + struct usb_gadget *gadget = dev->gadget; + + if (number == dev->config) + return 0; + +#ifdef CONFIG_USB_ETH_SA1100 + if (dev->config && atomic_read (&dev->tx_qlen) != 0) { + /* tx fifo is full, but we can't clear it...*/ + INFO (dev, "can't change configurations\n"); + return -ESPIPE; + } +#endif + eth_reset_config (dev); + hw_optimize (gadget); + + switch (number) { + case DEV_CONFIG_VALUE: + result = set_ether_config (dev, gfp_flags); + break; + default: + result = -EINVAL; + /* FALL THROUGH */ + case 0: + return result; + } + + if (result) + eth_reset_config (dev); + else { + char *speed; + + switch (gadget->speed) { + case USB_SPEED_FULL: speed = "full"; break; +#ifdef HIGHSPEED + case USB_SPEED_HIGH: speed = "high"; break; +#endif + default: speed = "?"; break; + } + + dev->config = number; + INFO (dev, "%s speed config #%d: %s\n", speed, number, + driver_desc); + } + return result; +} + +/*-------------------------------------------------------------------------*/ + +#ifdef EP_STATUS_NUM + +/* section 3.8.2 table 11 of the CDC spec lists Ethernet notifications */ +#define CDC_NOTIFY_NETWORK_CONNECTION 0x00 /* required; 6.3.1 */ +#define CDC_NOTIFY_SPEED_CHANGE 0x2a /* required; 6.3.8 */ + +struct cdc_notification { + u8 bmRequestType; + u8 bNotificationType; + u16 wValue; + u16 wIndex; + u16 wLength; + + /* SPEED_CHANGE data looks like this */ + u32 data [2]; +}; + +static void eth_status_complete (struct usb_ep *ep, struct usb_request *req) +{ + struct cdc_notification *event = req->buf; + int value = req->status; + struct eth_dev *dev = ep->driver_data; + + /* issue the second notification if host reads the first */ + if (event->bNotificationType == CDC_NOTIFY_NETWORK_CONNECTION + && value == 0) { + event->bmRequestType = 0xA1; + event->bNotificationType = CDC_NOTIFY_SPEED_CHANGE; + event->wValue = __constant_cpu_to_le16 (0); + event->wIndex = __constant_cpu_to_le16 (1); + event->wLength = __constant_cpu_to_le16 (8); + + /* SPEED_CHANGE data is up/down speeds in bits/sec */ + event->data [0] = event->data [1] = + (dev->gadget->speed == USB_SPEED_HIGH) + ? (13 * 512 * 8 * 1000 * 8) + : (19 * 64 * 1 * 1000 * 8); + + req->length = 16; + value = usb_ep_queue (ep, req, GFP_ATOMIC); + DEBUG (dev, "send SPEED_CHANGE --> %d\n", value); + if (value == 0) + return; + } else + DEBUG (dev, "event %02x --> %d\n", + event->bNotificationType, value); + + /* free when done */ + usb_ep_free_buffer (ep, req->buf, req->dma, 16); + usb_ep_free_request (ep, req); +} + +static void issue_start_status (struct eth_dev *dev) +{ + struct usb_request *req; + struct cdc_notification *event; + int value; + + DEBUG (dev, "%s, flush old status first\n", __FUNCTION__); + + /* flush old status + * + * FIXME ugly idiom, maybe we'd be better with just + * a "cancel the whole queue" primitive since any + * unlink-one primitive has way too many error modes. + * here, we "know" toggle is already clear... + */ + usb_ep_disable (dev->status_ep); + usb_ep_enable (dev->status_ep, dev->status); + + /* FIXME make these allocations static like dev->req */ + req = usb_ep_alloc_request (dev->status_ep, GFP_ATOMIC); + if (req == 0) { + DEBUG (dev, "status ENOMEM\n"); + return; + } + req->buf = usb_ep_alloc_buffer (dev->status_ep, 16, + &dev->req->dma, GFP_ATOMIC); + if (req->buf == 0) { + DEBUG (dev, "status buf ENOMEM\n"); +free_req: + usb_ep_free_request (dev->status_ep, req); + return; + } + + /* 3.8.1 says to issue first NETWORK_CONNECTION, then + * a SPEED_CHANGE. could be useful in some configs. + */ + event = req->buf; + event->bmRequestType = 0xA1; + event->bNotificationType = CDC_NOTIFY_NETWORK_CONNECTION; + event->wValue = __constant_cpu_to_le16 (1); /* connected */ + event->wIndex = __constant_cpu_to_le16 (1); + event->wLength = 0; + + req->length = 8; + req->complete = eth_status_complete; + value = usb_ep_queue (dev->status_ep, req, GFP_ATOMIC); + if (value < 0) { + DEBUG (dev, "status buf queue --> %d\n", value); + usb_ep_free_buffer (dev->status_ep, + req->buf, dev->req->dma, 16); + goto free_req; + } +} + +#endif + +/*-------------------------------------------------------------------------*/ + +static void eth_setup_complete (struct usb_ep *ep, struct usb_request *req) +{ + if (req->status || req->actual != req->length) + DEBUG ((struct eth_dev *) ep->driver_data, + "setup complete --> %d, %d/%d\n", + req->status, req->actual, req->length); +} + +/* see section 3.8.2 table 10 of the CDC spec for more ethernet + * requests, mostly for filters (multicast, pm) and statistics + */ +#define CDC_SET_ETHERNET_PACKET_FILTER 0x43 /* required */ + +/* + * The setup() callback implements all the ep0 functionality that's not + * handled lower down. CDC has a number of less-common features: + * + * - two interfaces: control, and ethernet data + * - data interface has two altsettings: default, and active + * - class-specific descriptors for the control interface + * - a mandatory class-specific control request + */ +static int +eth_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) +{ + struct eth_dev *dev = get_gadget_data (gadget); + struct usb_request *req = dev->req; + int value = -EOPNOTSUPP; + + /* descriptors just go into the pre-allocated ep0 buffer, + * while config change events may enable network traffic. + */ + switch (ctrl->bRequest) { + + case USB_REQ_GET_DESCRIPTOR: + if (ctrl->bRequestType != USB_DIR_IN) + break; + switch (ctrl->wValue >> 8) { + + case USB_DT_DEVICE: + value = min (ctrl->wLength, (u16) sizeof device_desc); + memcpy (req->buf, &device_desc, value); + break; +#ifdef HIGHSPEED + case USB_DT_DEVICE_QUALIFIER: + value = min (ctrl->wLength, (u16) sizeof dev_qualifier); + memcpy (req->buf, &dev_qualifier, value); + break; + + case USB_DT_OTHER_SPEED_CONFIG: + // FALLTHROUGH +#endif /* HIGHSPEED */ + case USB_DT_CONFIG: + value = config_buf (gadget->speed, req->buf, + ctrl->wValue >> 8, + ctrl->wValue & 0xff); + if (value >= 0) + value = min (ctrl->wLength, (u16) value); + break; + + case USB_DT_STRING: + value = usb_gadget_get_string (&stringtab, + ctrl->wValue & 0xff, req->buf); + if (value >= 0) + value = min (ctrl->wLength, (u16) value); + break; + } + break; + + case USB_REQ_SET_CONFIGURATION: + if (ctrl->bRequestType != 0) + break; + spin_lock (&dev->lock); + value = eth_set_config (dev, ctrl->wValue, GFP_ATOMIC); + spin_unlock (&dev->lock); + break; +#ifdef CONFIG_USB_ETH_PXA2XX + /* PXA UDC prevents us from using SET_INTERFACE in normal ways. + * And it hides GET_CONFIGURATION and GET_INTERFACE too. + */ + case USB_REQ_SET_INTERFACE: + spin_lock (&dev->lock); + value = eth_set_config (dev, DEV_CONFIG_VALUE, GFP_ATOMIC); + spin_unlock (&dev->lock); + break; + +#else /* hardware that that stays out of our way */ + case USB_REQ_GET_CONFIGURATION: + if (ctrl->bRequestType != USB_DIR_IN) + break; + *(u8 *)req->buf = dev->config; + value = min (ctrl->wLength, (u16) 1); + break; + + case USB_REQ_SET_INTERFACE: + if (ctrl->bRequestType != USB_RECIP_INTERFACE + || !dev->config + || ctrl->wIndex > 1) + break; + spin_lock (&dev->lock); + switch (ctrl->wIndex) { + case 0: /* control/master intf */ + if (ctrl->wValue != 0) + break; +#ifdef EP_STATUS_NUM + if (dev->status_ep) { + usb_ep_disable (dev->status_ep); + usb_ep_enable (dev->status_ep, dev->status); + } +#endif + value = 0; + break; + case 1: /* data intf */ + if (ctrl->wValue > 1) + break; + usb_ep_disable (dev->in_ep); + usb_ep_disable (dev->out_ep); + + /* CDC requires the data transfers not be done from + * the default interface setting ... also, setting + * the non-default interface clears filters etc. + */ + if (ctrl->wValue == 1) { + usb_ep_enable (dev->in_ep, dev->in); + usb_ep_enable (dev->out_ep, dev->out); + netif_carrier_on (dev->net); +#ifdef EP_STATUS_NUM + issue_start_status (dev); +#endif + if (netif_running (dev->net)) + eth_start (dev, GFP_ATOMIC); + } else { + netif_stop_queue (dev->net); + netif_carrier_off (dev->net); + } + value = 0; + break; + } + spin_unlock (&dev->lock); + break; + case USB_REQ_GET_INTERFACE: + if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE) + || !dev->config + || ctrl->wIndex > 1) + break; + + /* if carrier is on, data interface is active. */ + *(u8 *)req->buf = + ((ctrl->wIndex == 1) && netif_carrier_ok (dev->net)) + ? 1 + : 0, + value = min (ctrl->wLength, (u16) 1); + break; +#endif + +#ifdef DEV_CONFIG_CDC + case CDC_SET_ETHERNET_PACKET_FILTER: + /* see 6.2.30: no data, wIndex = interface, + * wValue = packet filter bitmap + */ + if (ctrl->bRequestType != (USB_TYPE_CLASS|USB_RECIP_INTERFACE) + || ctrl->wLength != 0 + || ctrl->wIndex > 1) + DEBUG (dev, "NOP packet filter %04x\n", ctrl->wValue); + /* NOTE: table 62 has 5 filter bits to reduce traffic, + * and we "must" support multicast and promiscuous. + * this NOP implements a bad filter... + */ + value = 0; + break; +#endif /* DEV_CONFIG_CDC */ + + default: + VDEBUG (dev, + "unknown control req%02x.%02x v%04x i%04x l%d\n", + ctrl->bRequestType, ctrl->bRequest, + ctrl->wValue, ctrl->wIndex, ctrl->wLength); + } + + /* respond with data transfer before status phase? */ + if (value >= 0) { + req->length = value; + value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC); + if (value < 0) { + DEBUG (dev, "ep_queue --> %d\n", value); + req->status = 0; + eth_setup_complete (gadget->ep0, req); + } + } + + /* host either stalls (value < 0) or reports success */ + return value; +} + +static void +eth_disconnect (struct usb_gadget *gadget) +{ + struct eth_dev *dev = get_gadget_data (gadget); + unsigned long flags; + + spin_lock_irqsave (&dev->lock, flags); + netif_stop_queue (dev->net); + netif_carrier_off (dev->net); + eth_reset_config (dev); + spin_unlock_irqrestore (&dev->lock, flags); + + /* next we may get setup() calls to enumerate new connections; + * or an unbind() during shutdown (including removing module). + */ +} + +/*-------------------------------------------------------------------------*/ + +/* NETWORK DRIVER HOOKUP (to the layer above this driver) */ + +static int eth_change_mtu (struct net_device *net, int new_mtu) +{ + struct eth_dev *dev = (struct eth_dev *) net->priv; + + if (new_mtu <= MIN_PACKET || new_mtu > MAX_PACKET) + return -ERANGE; + /* no zero-length packet read wanted after mtu-sized packets */ + if (((new_mtu + sizeof (struct ethhdr)) % dev->in_ep->maxpacket) == 0) + return -EDOM; + net->mtu = new_mtu; + return 0; +} + +static struct net_device_stats *eth_get_stats (struct net_device *net) +{ + return &((struct eth_dev *) net->priv)->stats; +} + +static int eth_ethtool_ioctl (struct net_device *net, void *useraddr) +{ + struct eth_dev *dev = (struct eth_dev *) net->priv; + u32 cmd; + + if (get_user (cmd, (u32 *)useraddr)) + return -EFAULT; + switch (cmd) { + + case ETHTOOL_GDRVINFO: { /* get driver info */ + struct ethtool_drvinfo info; + + memset (&info, 0, sizeof info); + info.cmd = ETHTOOL_GDRVINFO; + strncpy (info.driver, shortname, sizeof info.driver); + strncpy (info.version, DRIVER_VERSION, sizeof info.version); + strncpy (info.fw_version, CHIP, sizeof info.fw_version); + strncpy (info.bus_info, dev->gadget->dev.bus_id, + sizeof info.bus_info); + if (copy_to_user (useraddr, &info, sizeof (info))) + return -EFAULT; + return 0; + } + + case ETHTOOL_GLINK: { /* get link status */ + struct ethtool_value edata = { ETHTOOL_GLINK }; + + edata.data = (dev->gadget->speed != USB_SPEED_UNKNOWN); + if (copy_to_user (useraddr, &edata, sizeof (edata))) + return -EFAULT; + return 0; + } + + } + /* Note that the ethtool user space code requires EOPNOTSUPP */ + return -EOPNOTSUPP; +} + +static int eth_ioctl (struct net_device *net, struct ifreq *rq, int cmd) +{ + switch (cmd) { + case SIOCETHTOOL: + return eth_ethtool_ioctl (net, (void *)rq->ifr_data); + default: + return -EOPNOTSUPP; + } +} + +static void defer_kevent (struct eth_dev *dev, int flag) +{ + if (test_and_set_bit (flag, &dev->todo)) + return; + if (!schedule_work (&dev->work)) + ERROR (dev, "kevent %d may have been dropped\n", flag); + else + DEBUG (dev, "kevent %d scheduled\n", flag); +} + +static void rx_complete (struct usb_ep *ep, struct usb_request *req); + +static int +rx_submit (struct eth_dev *dev, struct usb_request *req, int gfp_flags) +{ + struct sk_buff *skb; + int retval = 0; + size_t size; + + size = (sizeof (struct ethhdr) + dev->net->mtu + RX_EXTRA); + + if ((skb = alloc_skb (size, gfp_flags)) == 0) { + DEBUG (dev, "no rx skb\n"); + defer_kevent (dev, WORK_RX_MEMORY); + list_add (&req->list, &dev->rx_reqs); + return -ENOMEM; + } + + req->buf = skb->data; + req->length = size; + req->complete = rx_complete; + req->context = skb; + + retval = usb_ep_queue (dev->out_ep, req, gfp_flags); + if (retval == -ENOMEM) + defer_kevent (dev, WORK_RX_MEMORY); + if (retval) { + DEBUG (dev, "rx submit --> %d\n", retval); + dev_kfree_skb_any (skb); + list_add (&req->list, &dev->rx_reqs); + } + return retval; +} + +static void rx_complete (struct usb_ep *ep, struct usb_request *req) +{ + struct sk_buff *skb = req->context; + struct eth_dev *dev = ep->driver_data; + int status = req->status; + + switch (status) { + + /* normal completion */ + case 0: + skb_put (skb, req->actual); + if (MIN_PACKET > skb->len + || skb->len > (MAX_PACKET + ETH_HLEN)) { + dev->stats.rx_errors++; + dev->stats.rx_length_errors++; + DEBUG (dev, "rx length %d\n", skb->len); + break; + } + + skb->dev = dev->net; + skb->protocol = eth_type_trans (skb, dev->net); + dev->stats.rx_packets++; + dev->stats.rx_bytes += skb->len; + + /* no buffer copies needed, unless hardware can't + * use skb buffers. + */ + status = netif_rx (skb); + skb = 0; + break; + + /* software-driven interface shutdown */ + case -ECONNRESET: // unlink + case -ESHUTDOWN: // disconnect etc + VDEBUG (dev, "rx shutdown, code %d\n", status); + goto quiesce; + + /* for hardware automagic (such as pxa) */ + case -ECONNABORTED: // endpoint reset + DEBUG (dev, "rx %s reset\n", ep->name); + defer_kevent (dev, WORK_RX_MEMORY); +quiesce: + dev_kfree_skb_any (skb); + goto clean; + + /* data overrun */ + case -EOVERFLOW: + dev->stats.rx_over_errors++; + // FALLTHROUGH + + default: + dev->stats.rx_errors++; + DEBUG (dev, "rx status %d\n", status); + break; + } + + if (skb) + dev_kfree_skb_any (skb); + if (!netif_running (dev->net)) { +clean: + list_add (&req->list, &dev->rx_reqs); + req = 0; + } + if (req) + rx_submit (dev, req, GFP_ATOMIC); +} + +static int prealloc (struct list_head *list, struct usb_ep *ep, + unsigned n, int gfp_flags) +{ + unsigned i; + struct usb_request *req; + + if (!n) + return -ENOMEM; + + /* queue/recycle up to N requests */ + i = n; + list_for_each_entry (req, list, list) { + if (i-- == 0) + goto extra; + } + while (i--) { + req = usb_ep_alloc_request (ep, gfp_flags); + if (!req) + return list_empty (list) ? -ENOMEM : 0; + list_add (&req->list, list); + } + return 0; + +extra: + /* free extras */ + for (;;) { + struct list_head *next; + + next = req->list.next; + list_del (&req->list); + usb_ep_free_request (ep, req); + + if (next == list) + break; + + req = container_of (next, struct usb_request, list); + } + return 0; +} + +static int alloc_requests (struct eth_dev *dev, unsigned n, int gfp_flags) +{ + int status; + + status = prealloc (&dev->tx_reqs, dev->in_ep, n, gfp_flags); + if (status < 0) + goto fail; + status = prealloc (&dev->rx_reqs, dev->out_ep, n, gfp_flags); + if (status < 0) + goto fail; + return 0; +fail: + DEBUG (dev, "can't alloc requests\n"); + return status; +} + +static void rx_fill (struct eth_dev *dev, int gfp_flags) +{ + struct usb_request *req; + + clear_bit (WORK_RX_MEMORY, &dev->todo); + + /* fill unused rxq slots with some skb */ + while (!list_empty (&dev->rx_reqs)) { + req = container_of (dev->rx_reqs.next, + struct usb_request, list); + list_del_init (&req->list); + if (rx_submit (dev, req, gfp_flags) < 0) { + defer_kevent (dev, WORK_RX_MEMORY); + return; + } + } +} + +static void eth_work (void *_dev) +{ + struct eth_dev *dev = _dev; + + if (test_bit (WORK_RX_MEMORY, &dev->todo)) { + if (netif_running (dev->net)) + rx_fill (dev, GFP_KERNEL); + else + clear_bit (WORK_RX_MEMORY, &dev->todo); + } + + if (dev->todo) + DEBUG (dev, "work done, flags = 0x%lx\n", dev->todo); +} + +static void tx_complete (struct usb_ep *ep, struct usb_request *req) +{ + struct sk_buff *skb = req->context; + struct eth_dev *dev = ep->driver_data; + + switch (req->status) { + default: + dev->stats.tx_errors++; + VDEBUG (dev, "tx err %d\n", req->status); + /* FALLTHROUGH */ + case -ECONNRESET: // unlink + case -ESHUTDOWN: // disconnect etc + break; + case 0: + dev->stats.tx_bytes += skb->len; + } + dev->stats.tx_packets++; + + list_add (&req->list, &dev->tx_reqs); + dev_kfree_skb_any (skb); + + atomic_dec (&dev->tx_qlen); + if (netif_carrier_ok (dev->net)) + netif_wake_queue (dev->net); +} + +static int eth_start_xmit (struct sk_buff *skb, struct net_device *net) +{ + struct eth_dev *dev = (struct eth_dev *) net->priv; + int length = skb->len; + int retval; + struct usb_request *req = 0; + + req = container_of (dev->tx_reqs.next, struct usb_request, list); + list_del (&req->list); + if (list_empty (&dev->tx_reqs)) + netif_stop_queue (net); + + /* no buffer copies needed, unless the network stack did it + * or the hardware can't use skb buffers. + */ + req->buf = skb->data; + req->context = skb; + req->complete = tx_complete; + +#ifdef CONFIG_USB_ETH_SA1100 + /* don't demand zlp (req->zero) support from all hardware */ + if ((length % dev->in_ep->maxpacket) == 0) + length++; +#else + /* use zlp framing on tx for strict CDC-Ether conformance, + * though any robust network rx path ignores extra padding. + */ + req->zero = 1; +#endif + req->length = length; + +#ifdef HIGHSPEED + /* throttle highspeed IRQ rate back slightly */ + req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH) + ? ((atomic_read (&dev->tx_qlen) % TX_DELAY) != 0) + : 0; +#endif + + retval = usb_ep_queue (dev->in_ep, req, GFP_ATOMIC); + switch (retval) { + default: + DEBUG (dev, "tx queue err %d\n", retval); + break; + case 0: + net->trans_start = jiffies; + atomic_inc (&dev->tx_qlen); + } + + if (retval) { + dev->stats.tx_dropped++; + dev_kfree_skb_any (skb); + if (list_empty (&dev->tx_reqs)) + netif_start_queue (net); + list_add (&req->list, &dev->tx_reqs); + } + return 0; +} + +static void eth_start (struct eth_dev *dev, int gfp_flags) +{ + DEBUG (dev, "%s\n", __FUNCTION__); + + /* fill the rx queue */ + rx_fill (dev, gfp_flags); + + /* and open the tx floodgates */ + atomic_set (&dev->tx_qlen, 0); + netif_wake_queue (dev->net); +} + +static int eth_open (struct net_device *net) +{ + struct eth_dev *dev = (struct eth_dev *) net->priv; + + DEBUG (dev, "%s\n", __FUNCTION__); + if (netif_carrier_ok (dev->net)) + eth_start (dev, GFP_KERNEL); + return 0; +} + +static int eth_stop (struct net_device *net) +{ + struct eth_dev *dev = (struct eth_dev *) net->priv; + + DEBUG (dev, "%s\n", __FUNCTION__); + netif_stop_queue (net); + + DEBUG (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n", + dev->stats.rx_packets, dev->stats.tx_packets, + dev->stats.rx_errors, dev->stats.tx_errors + ); + + /* ensure there are no more active requests */ + if (dev->gadget->speed != USB_SPEED_UNKNOWN) { + usb_ep_disable (dev->in_ep); + usb_ep_disable (dev->out_ep); + if (netif_carrier_ok (dev->net)) { + DEBUG (dev, "host still using in/out endpoints\n"); + usb_ep_enable (dev->in_ep, dev->in); + usb_ep_enable (dev->out_ep, dev->out); + } +#ifdef EP_STATUS_NUM + usb_ep_disable (dev->status_ep); + usb_ep_enable (dev->status_ep, dev->status); +#endif + } + + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static void +eth_unbind (struct usb_gadget *gadget) +{ + struct eth_dev *dev = get_gadget_data (gadget); + struct usb_request *req; + + DEBUG (dev, "unbind\n"); + + /* we've already been disconnected ... no i/o is active */ + if (dev->req) { + usb_ep_free_buffer (gadget->ep0, + dev->req->buf, dev->req->dma, + USB_BUFSIZ); + usb_ep_free_request (gadget->ep0, dev->req); + dev->req = 0; + } + + while (!list_empty (&dev->tx_reqs)) { + req = container_of (dev->tx_reqs.next, + struct usb_request, list); + list_del (&req->list); + usb_ep_free_request (dev->in_ep, req); + } + while (!list_empty (&dev->rx_reqs)) { + req = container_of (dev->rx_reqs.next, + struct usb_request, list); + list_del (&req->list); + usb_ep_free_request (dev->out_ep, req); + } + + unregister_netdev (dev->net); + dev_put (dev->net); + + /* assuming we used keventd, it must quiesce too */ + flush_scheduled_work (); + set_gadget_data (gadget, 0); +} + +static int +eth_bind (struct usb_gadget *gadget) +{ + struct eth_dev *dev; + struct net_device *net; + int status = -ENOMEM; +#ifdef DEV_CONFIG_CDC + u8 node_id [ETH_ALEN]; + + /* just one upstream link at a time */ + if (ethaddr [0] != 0) + return -ENODEV; +#endif + + net = alloc_etherdev (sizeof *dev); + if (!net) + return status; + dev = net->priv; + spin_lock_init (&dev->lock); + INIT_WORK (&dev->work, eth_work, dev); + INIT_LIST_HEAD (&dev->tx_reqs); + INIT_LIST_HEAD (&dev->rx_reqs); + + /* network device setup */ + dev->net = net; + SET_MODULE_OWNER (net); + net->priv = dev; + strcpy (net->name, "usb%d"); + ether_setup (net); + + /* one random address for the gadget device ... both of these could + * reasonably come from an id prom or a module parameter. + */ + get_random_bytes (net->dev_addr, ETH_ALEN); + net->dev_addr [0] &= 0xfe; // clear multicast bit + net->dev_addr [0] |= 0x02; // set local assignment bit (IEEE802) + +#ifdef DEV_CONFIG_CDC + /* ... another address for the host, on the other end of the + * link, gets exported through CDC (see CDC spec table 41) + */ + get_random_bytes (node_id, sizeof node_id); + node_id [0] &= 0xfe; // clear multicast bit + node_id [0] |= 0x02; // set local assignment bit (IEEE802) + snprintf (ethaddr, sizeof ethaddr, "%02X%02X%02X%02X%02X%02X", + node_id [0], node_id [1], node_id [2], + node_id [3], node_id [4], node_id [5]); +#endif + + net->change_mtu = eth_change_mtu; + net->get_stats = eth_get_stats; + net->hard_start_xmit = eth_start_xmit; + net->open = eth_open; + net->stop = eth_stop; + // watchdog_timeo, tx_timeout ... + // set_multicast_list + net->do_ioctl = eth_ioctl; + + /* preallocate control response and buffer */ + dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); + if (!dev->req) + goto fail; + dev->req->complete = eth_setup_complete; + dev->req->buf = usb_ep_alloc_buffer (gadget->ep0, USB_BUFSIZ, + &dev->req->dma, GFP_KERNEL); + if (!dev->req->buf) { + usb_ep_free_request (gadget->ep0, dev->req); + goto fail; + } + + /* finish hookup to lower layer ... */ + dev->gadget = gadget; + set_gadget_data (gadget, dev); + gadget->ep0->driver_data = dev; + INFO (dev, "%s, " CHIP ", version: " DRIVER_VERSION "\n", driver_desc); +#ifdef DEV_CONFIG_CDC + INFO (dev, "CDC host enet %s\n", ethaddr); +#endif + + /* two kinds of host-initiated state changes: + * - iff DATA transfer is active, carrier is "on" + * - tx queueing enabled if open *and* carrier is "on" + */ + netif_stop_queue (dev->net); + netif_carrier_off (dev->net); + + // SET_NETDEV_DEV (dev->net, &gadget->dev); + status = register_netdev (dev->net); + if (status == 0) + return status; +fail: + eth_unbind (gadget); + return status; +} + +/*-------------------------------------------------------------------------*/ + +static struct usb_gadget_driver eth_driver = { +#ifdef HIGHSPEED + .speed = USB_SPEED_HIGH, +#else + .speed = USB_SPEED_FULL, +#endif + .function = (char *) driver_desc, + .bind = eth_bind, + .unbind = eth_unbind, + + .setup = eth_setup, + .disconnect = eth_disconnect, + + .driver = { + .name = (char *) shortname, + // .shutdown = ... + // .suspend = ... + // .resume = ... + }, +}; + +MODULE_DESCRIPTION (DRIVER_DESC); +MODULE_AUTHOR ("David Brownell"); +MODULE_LICENSE ("GPL"); + + +static int __init init (void) +{ + return usb_gadget_register_driver (ð_driver); +} +module_init (init); + +static void __exit cleanup (void) +{ + usb_gadget_unregister_driver (ð_driver); +} +module_exit (cleanup); +