usb gadget zero: split out source/sink config

This splits the gadget zero "source/sink" configuration into a standalone
"configuration driver", building on the composite gadget framework code.
It doesn't yet pull the original code out of gadget zero or update how
that driver is built.

Neither this, nor its sibling "loopback" configuration, is a function
driver that can be combined with other functions.  (The host "usbtest"
driver wouldn't know how to deal with that!)  However the code becomes
simpler because of this conversion, so it's a net win.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/f_sourcesink.c

+/*
+ * f_sourcesink.c - USB peripheral source/sink configuration driver
+ *
+ * Copyright (C) 2003-2008 David Brownell
+ * Copyright (C) 2008 by 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 <linux/device.h>
+
+#include "g_zero.h"
+#include "gadget_chips.h"
+
+
+/*
+ * SOURCE/SINK FUNCTION ... a primary testing vehicle for USB peripheral
+ * controller drivers.
+ *
+ * This just sinks bulk packets OUT to the peripheral and sources them IN
+ * to the host, optionally with specific data patterns for integrity tests.
+ * As such it supports basic functionality and load tests.
+ *
+ * In terms of control messaging, this supports all the standard requests
+ * plus two that support control-OUT tests.  If the optional "autoresume"
+ * mode is enabled, it provides good functional coverage for the "USBCV"
+ * test harness from USB-IF.
+ *
+ * Note that because this doesn't queue more than one request at a time,
+ * some other function must be used to test queueing logic.  The network
+ * link (g_ether) is the best overall option for that, since its TX and RX
+ * queues are relatively independent, will receive a range of packet sizes,
+ * and can often be made to run out completely.  Those issues are important
+ * when stress testing peripheral controller drivers.
+ *
+ *
+ * This is currently packaged as a configuration driver, which can't be
+ * combined with other functions to make composite devices.  However, it
+ * can be combined with other independent configurations.
+ */
+struct f_sourcesink {
+	struct usb_function	function;
+
+	struct usb_ep		*in_ep;
+	struct usb_ep		*out_ep;
+	struct timer_list	resume;
+};
+
+static inline struct f_sourcesink *func_to_ss(struct usb_function *f)
+{
+	return container_of(f, struct f_sourcesink, function);
+}
+
+static unsigned autoresume;
+module_param(autoresume, uint, 0);
+MODULE_PARM_DESC(autoresume, "zero, or seconds before remote wakeup");
+
+static unsigned pattern;
+module_param(pattern, uint, 0);
+MODULE_PARM_DESC(pattern, "0 = all zeroes, 1 = mod63 ");
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_interface_descriptor source_sink_intf = {
+	.bLength =		sizeof source_sink_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	.bNumEndpoints =	2,
+	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
+	/* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+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 struct usb_descriptor_header *fs_source_sink_descs[] = {
+	(struct usb_descriptor_header *) &source_sink_intf,
+	(struct usb_descriptor_header *) &fs_sink_desc,
+	(struct usb_descriptor_header *) &fs_source_desc,
+	NULL,
+};
+
+/* high speed support: */
+
+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_descriptor_header *hs_source_sink_descs[] = {
+	(struct usb_descriptor_header *) &source_sink_intf,
+	(struct usb_descriptor_header *) &hs_source_desc,
+	(struct usb_descriptor_header *) &hs_sink_desc,
+	NULL,
+};
+
+/* function-specific strings: */
+
+static struct usb_string strings_sourcesink[] = {
+	[0].s = "source and sink data",
+	{  }			/* end of list */
+};
+
+static struct usb_gadget_strings stringtab_sourcesink = {
+	.language	= 0x0409,	/* en-us */
+	.strings	= strings_sourcesink,
+};
+
+static struct usb_gadget_strings *sourcesink_strings[] = {
+	&stringtab_sourcesink,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static void sourcesink_autoresume(unsigned long _c)
+{
+	struct usb_composite_dev *cdev = (void *)_c;
+	struct usb_gadget	*g = cdev->gadget;
+
+	/* Normally the host would be woken up for something
+	 * more significant than just a timer firing; likely
+	 * because of some direct user request.
+	 */
+	if (g->speed != USB_SPEED_UNKNOWN) {
+		int status = usb_gadget_wakeup(g);
+		DBG(cdev, "%s --> %d\n", __func__, status);
+	}
+}
+
+static int __init
+sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct f_sourcesink	*ss = func_to_ss(f);
+	int	id;
+
+	/* allocate interface ID(s) */
+	id = usb_interface_id(c, f);
+	if (id < 0)
+		return id;
+	source_sink_intf.bInterfaceNumber = id;
+
+	/* allocate endpoints */
+	ss->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_source_desc);
+	if (!ss->in_ep) {
+autoconf_fail:
+		ERROR(cdev, "%s: can't autoconfigure on %s\n",
+			f->name, cdev->gadget->name);
+		return -ENODEV;
+	}
+	ss->in_ep->driver_data = cdev;	/* claim */
+
+	ss->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_sink_desc);
+	if (!ss->out_ep)
+		goto autoconf_fail;
+	ss->out_ep->driver_data = cdev;	/* claim */
+
+	setup_timer(&ss->resume, sourcesink_autoresume,
+			(unsigned long) c->cdev);
+
+	/* support high speed hardware */
+	if (gadget_is_dualspeed(c->cdev->gadget)) {
+		hs_source_desc.bEndpointAddress =
+				fs_source_desc.bEndpointAddress;
+		hs_sink_desc.bEndpointAddress =
+				fs_sink_desc.bEndpointAddress;
+		f->hs_descriptors = hs_source_sink_descs;
+	}
+
+	DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			f->name, ss->in_ep->name, ss->out_ep->name);
+	return 0;
+}
+
+static void
+sourcesink_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	kfree(func_to_ss(f));
+}
+
+/* optionally require specific source/sink data patterns  */
+static int check_read_data(struct f_sourcesink *ss, struct usb_request *req)
+{
+	unsigned		i;
+	u8			*buf = req->buf;
+	struct usb_composite_dev *cdev = ss->function.config->cdev;
+
+	for (i = 0; i < req->actual; i++, buf++) {
+		switch (pattern) {
+
+		/* all-zeroes has no synchronization issues */
+		case 0:
+			if (*buf == 0)
+				continue;
+			break;
+
+		/* "mod63" stays in sync with short-terminated transfers,
+		 * OR otherwise when host and gadget agree on how large
+		 * each usb transfer request should be.  Resync is done
+		 * with set_interface or set_config.  (We *WANT* it to
+		 * get quickly out of sync if controllers or their drivers
+		 * stutter for any reason, including buffer duplcation...)
+		 */
+		case 1:
+			if (*buf == (u8)(i % 63))
+				continue;
+			break;
+		}
+		ERROR(cdev, "bad OUT byte, buf[%d] = %d\n", i, *buf);
+		usb_ep_set_halt(ss->out_ep);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void reinit_write_data(struct usb_ep *ep, struct usb_request *req)
+{
+	unsigned	i;
+	u8		*buf = req->buf;
+
+	switch (pattern) {
+	case 0:
+		memset(req->buf, 0, req->length);
+		break;
+	case 1:
+		for  (i = 0; i < req->length; i++)
+			*buf++ = (u8) (i % 63);
+		break;
+	}
+}
+
+static void source_sink_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_sourcesink	*ss = ep->driver_data;
+	struct usb_composite_dev *cdev = ss->function.config->cdev;
+	int			status = req->status;
+
+	switch (status) {
+
+	case 0:				/* normal completion? */
+		if (ep == ss->out_ep) {
+			check_read_data(ss, req);
+			memset(req->buf, 0x55, req->length);
+		} else
+			reinit_write_data(ep, req);
+		break;
+
+	/* this endpoint is normally active while we're configured */
+	case -ECONNABORTED:		/* hardware forced ep reset */
+	case -ECONNRESET:		/* request dequeued */
+	case -ESHUTDOWN:		/* disconnect from host */
+		VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
+				req->actual, req->length);
+		if (ep == ss->out_ep)
+			check_read_data(ss, req);
+		free_ep_req(ep, req);
+		return;
+
+	case -EOVERFLOW:		/* buffer overrun on read means that
+					 * we didn't provide a big enough
+					 * buffer.
+					 */
+	default:
+#if 1
+		DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
+				status, req->actual, req->length);
+#endif
+	case -EREMOTEIO:		/* short read */
+		break;
+	}
+
+	status = usb_ep_queue(ep, req, GFP_ATOMIC);
+	if (status) {
+		ERROR(cdev, "kill %s:  resubmit %d bytes --> %d\n",
+				ep->name, req->length, status);
+		usb_ep_set_halt(ep);
+		/* FIXME recover later ... somehow */
+	}
+}
+
+static int source_sink_start_ep(struct f_sourcesink *ss, bool is_in)
+{
+	struct usb_ep		*ep;
+	struct usb_request	*req;
+	int			status;
+
+	ep = is_in ? ss->in_ep : ss->out_ep;
+	req = alloc_ep_req(ep);
+	if (!req)
+		return -ENOMEM;
+
+	req->complete = source_sink_complete;
+	if (is_in)
+		reinit_write_data(ep, req);
+	else
+		memset(req->buf, 0x55, req->length);
+
+	status = usb_ep_queue(ep, req, GFP_ATOMIC);
+	if (status) {
+		struct usb_composite_dev	*cdev;
+
+		cdev = ss->function.config->cdev;
+		ERROR(cdev, "start %s %s --> %d\n",
+				is_in ? "IN" : "OUT",
+				ep->name, status);
+		free_ep_req(ep, req);
+	}
+
+	return status;
+}
+
+static void disable_source_sink(struct f_sourcesink *ss)
+{
+	struct usb_composite_dev	*cdev;
+
+	cdev = ss->function.config->cdev;
+	disable_endpoints(cdev, ss->in_ep, ss->out_ep);
+	del_timer(&ss->resume);
+	VDBG(cdev, "%s disabled\n", ss->function.name);
+}
+
+static int
+enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss)
+{
+	int					result = 0;
+	const struct usb_endpoint_descriptor	*src, *sink;
+	struct usb_ep				*ep;
+
+	src = ep_choose(cdev->gadget, &hs_source_desc, &fs_source_desc);
+	sink = ep_choose(cdev->gadget, &hs_sink_desc, &fs_sink_desc);
+
+	/* one endpoint writes (sources) zeroes IN (to the host) */
+	ep = ss->in_ep;
+	result = usb_ep_enable(ep, src);
+	if (result < 0)
+		return result;
+	ep->driver_data = ss;
+
+	result = source_sink_start_ep(ss, true);
+	if (result < 0) {
+fail:
+		ep = ss->in_ep;
+		usb_ep_disable(ep);
+		ep->driver_data = NULL;
+		return result;
+	}
+
+	/* one endpoint reads (sinks) anything OUT (from the host) */
+	ep = ss->out_ep;
+	result = usb_ep_enable(ep, sink);
+	if (result < 0)
+		goto fail;
+	ep->driver_data = ss;
+
+	result = source_sink_start_ep(ss, false);
+	if (result < 0) {
+		usb_ep_disable(ep);
+		ep->driver_data = NULL;
+		goto fail;
+	}
+
+	DBG(cdev, "%s enabled\n", ss->function.name);
+	return result;
+}
+
+static int sourcesink_set_alt(struct usb_function *f,
+		unsigned intf, unsigned alt)
+{
+	struct f_sourcesink	*ss = func_to_ss(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	/* we know alt is zero */
+	if (ss->in_ep->driver_data)
+		disable_source_sink(ss);
+	return enable_source_sink(cdev, ss);
+}
+
+static void sourcesink_disable(struct usb_function *f)
+{
+	struct f_sourcesink	*ss = func_to_ss(f);
+
+	disable_source_sink(ss);
+}
+
+static void sourcesink_suspend(struct usb_function *f)
+{
+	struct f_sourcesink	*ss = func_to_ss(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	if (cdev->gadget->speed == USB_SPEED_UNKNOWN)
+		return;
+
+	if (autoresume) {
+		mod_timer(&ss->resume, jiffies + (HZ * autoresume));
+		DBG(cdev, "suspend, wakeup in %d seconds\n", autoresume);
+	} else
+		DBG(cdev, "%s\n", __func__);
+}
+
+static void sourcesink_resume(struct usb_function *f)
+{
+	struct f_sourcesink	*ss = func_to_ss(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	DBG(cdev, "%s\n", __func__);
+	del_timer(&ss->resume);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __init sourcesink_bind_config(struct usb_configuration *c)
+{
+	struct f_sourcesink	*ss;
+	int			status;
+
+	ss = kzalloc(sizeof *ss, GFP_KERNEL);
+	if (!ss)
+		return -ENOMEM;
+
+	ss->function.name = "source/sink";
+	ss->function.descriptors = fs_source_sink_descs;
+	ss->function.bind = sourcesink_bind;
+	ss->function.unbind = sourcesink_unbind;
+	ss->function.set_alt = sourcesink_set_alt;
+	ss->function.disable = sourcesink_disable;
+	ss->function.suspend = sourcesink_suspend;
+	ss->function.resume = sourcesink_resume;
+
+	status = usb_add_function(c, &ss->function);
+	if (status)
+		kfree(ss);
+	return status;
+}
+
+static int sourcesink_setup(struct usb_configuration *c,
+		const struct usb_ctrlrequest *ctrl)
+{
+	struct usb_request	*req = c->cdev->req;
+	int			value = -EOPNOTSUPP;
+	u16			w_index = le16_to_cpu(ctrl->wIndex);
+	u16			w_value = le16_to_cpu(ctrl->wValue);
+	u16			w_length = le16_to_cpu(ctrl->wLength);
+
+	/* composite driver infrastructure handles everything except
+	 * the two control test requests.
+	 */
+	switch (ctrl->bRequest) {
+
+	/*
+	 * These are the same vendor-specific requests supported by
+	 * Intel's USB 2.0 compliance test devices.  We exceed that
+	 * device spec by allowing multiple-packet requests.
+	 *
+	 * NOTE:  the Control-OUT data stays in req->buf ... better
+	 * would be copying it into a scratch buffer, so that other
+	 * requests may safely intervene.
+	 */
+	case 0x5b:	/* control WRITE test -- fill the buffer */
+		if (ctrl->bRequestType != (USB_DIR_OUT|USB_TYPE_VENDOR))
+			goto unknown;
+		if (w_value || w_index)
+			break;
+		/* just read that many bytes into the buffer */
+		if (w_length > req->length)
+			break;
+		value = w_length;
+		break;
+	case 0x5c:	/* control READ test -- return the buffer */
+		if (ctrl->bRequestType != (USB_DIR_IN|USB_TYPE_VENDOR))
+			goto unknown;
+		if (w_value || w_index)
+			break;
+		/* expect those bytes are still in the buffer; send back */
+		if (w_length > req->length)
+			break;
+		value = w_length;
+		break;
+
+	default:
+unknown:
+		VDBG(c->cdev,
+			"unknown control req%02x.%02x v%04x i%04x l%d\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+	}
+
+	/* respond with data transfer or status phase? */
+	if (value >= 0) {
+		VDBG(c->cdev, "source/sink req%02x.%02x v%04x i%04x l%d\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+		req->zero = 0;
+		req->length = value;
+		value = usb_ep_queue(c->cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (value < 0)
+			ERROR(c->cdev, "source/sinkc response, err %d\n",
+					value);
+	}
+
+	/* device either stalls (value < 0) or reports success */
+	return value;
+}
+
+static struct usb_configuration sourcesink_driver = {
+	.label		= "source/sink",
+	.strings	= sourcesink_strings,
+	.bind		= sourcesink_bind_config,
+	.setup		= sourcesink_setup,
+	.bConfigurationValue = 3,
+	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
+	.bMaxPower	= 1,	/* 2 mA, minimal */
+	/* .iConfiguration = DYNAMIC */
+};
+
+/**
+ * sourcesink_add - add a source/sink testing configuration to a device
+ * @cdev: the device to support the configuration
+ */
+int __init sourcesink_add(struct usb_composite_dev *cdev)
+{
+	int id;
+
+	/* allocate string ID(s) */
+	id = usb_string_id(cdev);
+	if (id < 0)
+		return id;
+	strings_sourcesink[0].id = id;
+
+	source_sink_intf.iInterface = id;
+	sourcesink_driver.iConfiguration = id;
+
+	/* support autoresume for remote wakeup testing */
+	if (autoresume)
+		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+
+	/* support OTG systems */
+	if (gadget_is_otg(cdev->gadget)) {
+		sourcesink_driver.descriptors = otg_desc;
+		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
+	return usb_add_config(cdev, &sourcesink_driver);
+}

drivers/usb/gadget/g_zero.h

+/*
+ * This header declares the utility functions used by "Gadget Zero", plus
+ * interfaces to its two single-configuration function drivers.
+ */
+
+#ifndef __G_ZERO_H
+#define __G_ZERO_H
+
+#include <linux/usb/composite.h>
+
+/* global state */
+extern const struct usb_descriptor_header *otg_desc[];
+
+/* common utilities */
+struct usb_request *alloc_ep_req(struct usb_ep *ep);
+void free_ep_req(struct usb_ep *ep, struct usb_request *req);
+void disable_endpoints(struct usb_composite_dev *cdev,
+		struct usb_ep *in, struct usb_ep *out);
+
+/* configuration-specific linkup */
+int sourcesink_add(struct usb_composite_dev *cdev);
+
+#endif /* __G_ZERO_H */