usb gadget zero: split out loopback config (e5760fda) · Commits · e / devices / android_kernel_sony_msm8998

drivers/usb/gadget/f_loopback.c

0 → 100644

+381 −0

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			/*
			* f_loopback.c - USB peripheral loopback 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"


			/*
			* LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
			*
			* This takes messages of various sizes written OUT to a device, and loops
			* them back so they can be read IN from it. It has been used by certain
			* test applications. It supports limited testing of data queueing logic.
			*
			*
			* 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_loopback {
			struct usb_function function;

			struct usb_ep *in_ep;
			struct usb_ep *out_ep;
			};

			static inline struct f_loopback func_to_loop(struct usb_function f)
			{
			return container_of(f, struct f_loopback, function);
			}

			static unsigned qlen = 32;
			module_param(qlen, uint, 0);
			MODULE_PARM_DESC(qlenn, "depth of loopback queue");

			/-------------------------------------------------------------------------/

			static struct usb_interface_descriptor loopback_intf = {
			.bLength = sizeof loopback_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_loopback_descs[] = {
			(struct usb_descriptor_header *) &loopback_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_loopback_descs[] = {
			(struct usb_descriptor_header *) &loopback_intf,
			(struct usb_descriptor_header *) &hs_source_desc,
			(struct usb_descriptor_header *) &hs_sink_desc,
			NULL,
			};

			/* function-specific strings: */

			static struct usb_string strings_loopback[] = {
			[0].s = "loop input to output",
			{ } /* end of list */
			};

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

			static struct usb_gadget_strings *loopback_strings[] = {
			&stringtab_loop,
			NULL,
			};

			/-------------------------------------------------------------------------/

			static int __init
			loopback_bind(struct usb_configuration c, struct usb_function f)
			{
			struct usb_composite_dev *cdev = c->cdev;
			struct f_loopback *loop = func_to_loop(f);
			int id;

			/* allocate interface ID(s) */
			id = usb_interface_id(c, f);
			if (id < 0)
			return id;
			loopback_intf.bInterfaceNumber = id;

			/* allocate endpoints */

			loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_source_desc);
			if (!loop->in_ep) {
			autoconf_fail:
			ERROR(cdev, "%s: can't autoconfigure on %s\n",
			f->name, cdev->gadget->name);
			return -ENODEV;
			}
			loop->in_ep->driver_data = cdev; /* claim */

			loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_sink_desc);
			if (!loop->out_ep)
			goto autoconf_fail;
			loop->out_ep->driver_data = cdev; /* claim */

			/* 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_loopback_descs;
			}

			DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
			f->name, loop->in_ep->name, loop->out_ep->name);
			return 0;
			}

			static void
			loopback_unbind(struct usb_configuration c, struct usb_function f)
			{
			kfree(func_to_loop(f));
			}

			static void loopback_complete(struct usb_ep ep, struct usb_request req)
			{
			struct f_loopback *loop = ep->driver_data;
			struct usb_composite_dev *cdev = loop->function.config->cdev;
			int status = req->status;

			switch (status) {

			case 0: /* normal completion? */
			if (ep == loop->out_ep) {
			/* loop this OUT packet back IN to the host */
			req->zero = (req->actual < req->length);
			req->length = req->actual;
			status = usb_ep_queue(loop->in_ep, req, GFP_ATOMIC);
			if (status == 0)
			return;

			/* "should never get here" */
			ERROR(cdev, "can't loop %s to %s: %d\n",
			ep->name, loop->in_ep->name,
			status);
			}

			/* queue the buffer for some later OUT packet */
			req->length = buflen;
			status = usb_ep_queue(loop->out_ep, req, GFP_ATOMIC);
			if (status == 0)
			return;

			/* "should never get here" */
			/* FALLTHROUGH */

			default:
			ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
			status, req->actual, req->length);
			/* FALLTHROUGH */

			/* NOTE: since this driver doesn't maintain an explicit record
			* of requests it submitted (just maintains qlen count), we
			* rely on the hardware driver to clean up on disconnect or
			* endpoint disable.
			*/
			case -ECONNABORTED: /* hardware forced ep reset */
			case -ECONNRESET: /* request dequeued */
			case -ESHUTDOWN: /* disconnect from host */
			free_ep_req(ep, req);
			return;
			}
			}

			static void disable_loopback(struct f_loopback *loop)
			{
			struct usb_composite_dev *cdev;

			cdev = loop->function.config->cdev;
			disable_endpoints(cdev, loop->in_ep, loop->out_ep);
			VDBG(cdev, "%s disabled\n", loop->function.name);
			}

			static int
			enable_loopback(struct usb_composite_dev cdev, struct f_loopback loop)
			{
			int result = 0;
			const struct usb_endpoint_descriptor src, sink;
			struct usb_ep *ep;
			struct usb_request *req;
			unsigned i;

			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 data back IN to the host */
			ep = loop->in_ep;
			result = usb_ep_enable(ep, src);
			if (result < 0)
			return result;
			ep->driver_data = loop;

			/* one endpoint just reads OUT packets */
			ep = loop->out_ep;
			result = usb_ep_enable(ep, sink);
			if (result < 0) {
			fail0:
			ep = loop->in_ep;
			usb_ep_disable(ep);
			ep->driver_data = NULL;
			return result;
			}
			ep->driver_data = loop;

			/* allocate a bunch of read buffers and queue them all at once.
			* we buffer at most 'qlen' transfers; fewer if any need more
			* than 'buflen' bytes each.
			*/
			for (i = 0; i < qlen && result == 0; i++) {
			req = alloc_ep_req(ep);
			if (req) {
			req->complete = loopback_complete;
			result = usb_ep_queue(ep, req, GFP_ATOMIC);
			if (result)
			ERROR(cdev, "%s queue req --> %d\n",
			ep->name, result);
			} else {
			usb_ep_disable(ep);
			ep->driver_data = NULL;
			result = -ENOMEM;
			goto fail0;
			}
			}

			DBG(cdev, "%s enabled\n", loop->function.name);
			return result;
			}

			static int loopback_set_alt(struct usb_function *f,
			unsigned intf, unsigned alt)
			{
			struct f_loopback *loop = func_to_loop(f);
			struct usb_composite_dev *cdev = f->config->cdev;

			/* we know alt is zero */
			if (loop->in_ep->driver_data)
			disable_loopback(loop);
			return enable_loopback(cdev, loop);
			}

			static void loopback_disable(struct usb_function *f)
			{
			struct f_loopback *loop = func_to_loop(f);

			disable_loopback(loop);
			}

			/-------------------------------------------------------------------------/

			static int __init loopback_bind_config(struct usb_configuration *c)
			{
			struct f_loopback *loop;
			int status;

			loop = kzalloc(sizeof *loop, GFP_KERNEL);
			if (!loop)
			return -ENOMEM;

			loop->function.name = "loopback";
			loop->function.descriptors = fs_loopback_descs;
			loop->function.bind = loopback_bind;
			loop->function.unbind = loopback_unbind;
			loop->function.set_alt = loopback_set_alt;
			loop->function.disable = loopback_disable;

			status = usb_add_function(c, &loop->function);
			if (status)
			kfree(loop);
			return status;
			}

			static struct usb_configuration loopback_driver = {
			.label = "loopback",
			.strings = loopback_strings,
			.bind = loopback_bind_config,
			.bConfigurationValue = 2,
			.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
			.bMaxPower = 1, /* 2 mA, minimal */
			/* .iConfiguration = DYNAMIC */
			};

			/**
			* loopback_add - add a loopback testing configuration to a device
			* @cdev: the device to support the loopback configuration
			*/
			int __init loopback_add(struct usb_composite_dev *cdev)
			{
			int id;

			/* allocate string ID(s) */
			id = usb_string_id(cdev);
			if (id < 0)
			return id;
			strings_loopback[0].id = id;

			loopback_intf.iInterface = id;
			loopback_driver.iConfiguration = id;

			/* support OTG systems */
			if (gadget_is_otg(cdev->gadget)) {
			loopback_driver.descriptors = otg_desc;
			loopback_driver.bmAttributes \|= USB_CONFIG_ATT_WAKEUP;
			}

			return usb_add_config(cdev, &loopback_driver);
			}

drivers/usb/gadget/g_zero.h

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -9,6 +9,7 @@
	#include <linux/usb/composite.h>		#include <linux/usb/composite.h>

	/* global state */		/* global state */
			extern unsigned buflen;
	extern const struct usb_descriptor_header *otg_desc[];		extern const struct usb_descriptor_header *otg_desc[];

	/* common utilities */		/* common utilities */
	@@ -19,5 +20,6 @@ void disable_endpoints(struct usb_composite_dev *cdev,

	/* configuration-specific linkup */		/* configuration-specific linkup */
	int sourcesink_add(struct usb_composite_dev *cdev);		int sourcesink_add(struct usb_composite_dev *cdev);
			int loopback_add(struct usb_composite_dev *cdev);

	#endif /* __G_ZERO_H */		#endif /* __G_ZERO_H */