zero.c

linux-2.6.15.6

/*
 * zero.c -- Gadget Zero, for USB development
 *
 * Copyright (C) 2003-2004 David Brownell
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The names of the above-listed copyright holders may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") as published by the Free Software
 * Foundation, either version 2 of that License or (at your option) any
 * later version.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


/*
 * Gadget Zero only needs two bulk endpoints, and is an example of how you
 * can write a hardware-agnostic gadget driver running inside a USB device.
 *
 * Hardware details are visible (see CONFIG_USB_ZERO_* below) but don't
 * affect most of the driver.
 *
 * Use it with the Linux host/master side "usbtest" driver to get a basic
 * functional test of your device-side usb stack, or with "usb-skeleton".
 *
 * It supports two similar configurations.  One sinks whatever the usb host
 * writes, and in return sources zeroes.  The other loops whatever the host
 * writes back, so the host can read it.  Module options include:
 *
 *   buflen=N		default N=4096, buffer size used
 *   qlen=N		default N=32, how many buffers in the loopback queue
 *   loopdefault	default false, list loopback config first
 *
 * Many drivers will only have one configuration, letting them be much
 * simpler if they also don't support high speed operation (like this
 * driver does).
 */

#define DEBUG 1
// #define VERBOSE

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/utsname.h>
#include <linux/device.h>
#include <linux/moduleparam.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>

#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>

#include "gadget_chips.h"


/*-------------------------------------------------------------------------*/

#define DRIVER_VERSION		"St Patrick's Day 2004"

static const char shortname [] = "zero";
static const char longname [] = "Gadget Zero";

static const char source_sink [] = "source and sink data";
static const char loopback [] = "loop input to output";

/*-------------------------------------------------------------------------*/

/*
 * driver assumes self-powered hardware, and
 * has no way for users to trigger remote wakeup.
 *
 * this version autoconfigures as much as possible,
 * which is reasonable for most "bulk-only" drivers.
 */
static const char *EP_IN_NAME;		/* source */
static const char *EP_OUT_NAME;		/* sink */

/*-------------------------------------------------------------------------*/

/* big enough to hold our biggest descriptor */
#define USB_BUFSIZ	256

struct zero_dev {
	spinlock_t		lock;
	struct usb_gadget	*gadget;
	struct usb_request	*req;		/* for control responses */

	/* when configured, we have one of two configs:
	 * - source data (in to host) and sink it (out from host)
	 * - or loop it back (out from host back in to host)
	 */
	u8			config;
	struct usb_ep		*in_ep, *out_ep;

	/* autoresume timer */
	struct timer_list	resume;
};

#define xprintk(d,level,fmt,args...) \
	dev_printk(level , &(d)->gadget->dev , fmt , ## args)

#ifdef DEBUG
#define DBG(dev,fmt,args...) \
	xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev,fmt,args...) \
	do { } while (0)
#endif /* DEBUG */

#ifdef VERBOSE
#define VDBG	DBG
#else
#define VDBG(dev,fmt,args...) \
	do { } while (0)
#endif /* VERBOSE */

#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)

/*-------------------------------------------------------------------------*/

static unsigned buflen = 4096;
static unsigned qlen = 32;
static unsigned pattern = 0;

module_param (buflen, uint, S_IRUGO|S_IWUSR);
module_param (qlen, uint, S_IRUGO|S_IWUSR);
module_param (pattern, uint, S_IRUGO|S_IWUSR);

/*
 * if it's nonzero, autoresume says how many seconds to wait
 * before trying to wake up the host after suspend.
 */
static unsigned autoresume = 0;
module_param (autoresume, uint, 0);

/*
 * Normally the "loopback" configuration is second (index 1) so
 * it's not the default.  Here's where to change that order, to
 * work better with hosts where config changes are problematic.
 * Or controllers (like superh) that only support one config.
 */
static int loopdefault = 0;

module_param (loopdefault, bool, S_IRUGO|S_IWUSR);

/*-------------------------------------------------------------------------*/

/* 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.
 */
#ifndef	CONFIG_USB_ZERO_HNPTEST
#define DRIVER_VENDOR_NUM	0x0525		/* NetChip */
#define DRIVER_PRODUCT_NUM	0xa4a0		/* Linux-USB "Gadget Zero" */
#else
#define DRIVER_VENDOR_NUM	0x1a0a		/* OTG test device IDs */
#define DRIVER_PRODUCT_NUM	0xbadd
#endif

/*-------------------------------------------------------------------------*/

/*
 * DESCRIPTORS ... most are static, but strings and (full)
 * configuration descriptors are built on demand.
 */

#define STRING_MANUFACTURER		25
#define STRING_PRODUCT			42
#define STRING_SERIAL			101
#define STRING_SOURCE_SINK		250
#define STRING_LOOPBACK			251

/*
 * This device advertises two configurations; these numbers work
 * on a pxa250 as well as more flexible hardware.
 */
#define	CONFIG_SOURCE_SINK	3
#define	CONFIG_LOOPBACK		2

static struct usb_device_descriptor
device_desc = {
	.bLength =		sizeof device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	.bcdUSB =		__constant_cpu_to_le16 (0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,

	.idVendor =		__constant_cpu_to_le16 (DRIVER_VENDOR_NUM),
	.idProduct =		__constant_cpu_to_le16 (DRIVER_PRODUCT_NUM),
	.iManufacturer =	STRING_MANUFACTURER,
	.iProduct =		STRING_PRODUCT,
	.iSerialNumber =	STRING_SERIAL,
	.bNumConfigurations =	2,
};

static struct usb_config_descriptor
source_sink_config = {
	.bLength =		sizeof source_sink_config,
	.bDescriptorType =	USB_DT_CONFIG,

	/* compute wTotalLength on the fly */
	.bNumInterfaces =	1,
	.bConfigurationValue =	CONFIG_SOURCE_SINK,
	.iConfiguration =	STRING_SOURCE_SINK,
	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
	.bMaxPower =		1,	/* self-powered */
};

static struct usb_config_descriptor
loopback_config = {
	.bLength =		sizeof loopback_config,
	.bDescriptorType =	USB_DT_CONFIG,

	/* compute wTotalLength on the fly */
	.bNumInterfaces =	1,
	.bConfigurationValue =	CONFIG_LOOPBACK,
	.iConfiguration =	STRING_LOOPBACK,
	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
	.bMaxPower =		1,	/* self-powered */
};

static struct usb_otg_descriptor
otg_descriptor = {
	.bLength =		sizeof otg_descriptor,
	.bDescriptorType =	USB_DT_OTG,

	.bmAttributes =		USB_OTG_SRP,
};

/* one interface in each configuration */

static const struct usb_interface_descriptor
source_sink_intf = {
	.bLength =		sizeof source_sink_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.iInterface =		STRING_SOURCE_SINK,
};

static const struct usb_interface_descriptor
loopback_intf = {
	.bLength =		sizeof loopback_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.iInterface =		STRING_LOOPBACK,
};

/* two full speed bulk endpoints; their use is config-dependent */

static struct usb_endpoint_descriptor
fs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor
fs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static const struct usb_descriptor_header *fs_source_sink_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &source_sink_intf,
	(struct usb_descriptor_header *) &fs_sink_desc,
	(struct usb_descriptor_header *) &fs_source_desc,
	NULL,
};

static const struct usb_descriptor_header *fs_loopback_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &fs_sink_desc,
	(struct usb_descriptor_header *) &fs_source_desc,
	NULL,
};

#ifdef	CONFIG_USB_GADGET_DUALSPEED

/*
 * usb 2.0 devices need to expose both high speed and full speed
 * descriptors, unless they only run at full speed.
 *
 * that means alternate endpoint descriptors (bigger packets)
 * and a "device qualifier" ... plus more construction options
 * for the config descriptor.
 */

static struct usb_endpoint_descriptor
hs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16 (512),
};

static struct usb_endpoint_descriptor
hs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16 (512),
};

static struct usb_qualifier_descriptor
dev_qualifier = {
	.bLength =		sizeof dev_qualifier,
	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,

	.bcdUSB =		__constant_cpu_to_le16 (0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,

	.bNumConfigurations =	2,
};

static const struct usb_descriptor_header *hs_source_sink_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &source_sink_intf,
	(struct usb_descriptor_header *) &hs_source_desc,
	(struct usb_descriptor_header *) &hs_sink_desc,
	NULL,
};

static const struct usb_descriptor_header *hs_loopback_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &hs_source_desc,
	(struct usb_descriptor_header *) &hs_sink_desc,
	NULL,
};

/* 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	/* !CONFIG_USB_GADGET_DUALSPEED */

static char				manufacturer [50];
static char				serial [40];

/* static strings, in UTF-8 */
static struct usb_string		strings [] = {
	{ STRING_MANUFACTURER, manufacturer, },
	{ STRING_PRODUCT, longname, },
	{ STRING_SERIAL, serial, },
	{ STRING_LOOPBACK, loopback, },
	{ STRING_SOURCE_SINK, source_sink, },
	{  }			/* end of list */
};

static struct usb_gadget_strings	stringtab = {
	.language	= 0x0409,	/* en-us */
	.strings	= strings,
};

/*
 * config descriptors are also handcrafted.  these must agree with code
 * that sets configurations, and with code managing interfaces and their
 * altsettings.  other complexity may come from:
 *
 *  - high speed support, including "other speed config" rules
 *  - multiple configurations
 *  - interfaces with alternate settings
 *  - embedded class or vendor-specific descriptors
 *
 * this handles high speed, and has a second config that could as easily
 * have been an alternate interface setting (on most hardware).
 *
 * NOTE:  to demonstrate (and test) more USB capabilities, this driver
 * should include an altsetting to test interrupt transfers, including
 * high bandwidth modes at high speed.  (Maybe work like Intel's test
 * device?)
 */
static int
config_buf (struct usb_gadget *gadget,
		u8 *buf, u8 type, unsigned index)
{
	int				is_source_sink;
	int				len;
	const struct usb_descriptor_header **function;
#ifdef CONFIG_USB_GADGET_DUALSPEED
	int				hs = (gadget->speed == USB_SPEED_HIGH);
#endif

	/* two configurations will always be index 0 and index 1 */