--- /dev/null
+/*
+ * 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);
+}