From 155d12d968007c25561159565ce5cf116a947434 Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Wed, 12 Jan 2011 04:03:57 +0000
Subject: [PATCH] Framework for HID keyboard -- not much there yet

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3245 42af7a65-404d-4744-a932-0658087f49c3
---
 ChangeLog                          |    7 +
 Documentation/NuttX.html           |   10 +-
 drivers/usbhost/Make.defs          |    2 +-
 drivers/usbhost/usbhost_hidkbd.c   | 1039 ++++++++++++++++++++++++++++
 drivers/usbhost/usbhost_skeleton.c | 1038 +++++++++++++++++++++++++++
 include/nuttx/usb/hid.h            |  190 +++++
 6 files changed, 2284 insertions(+), 2 deletions(-)
 create mode 100644 drivers/usbhost/usbhost_hidkbd.c
 create mode 100644 drivers/usbhost/usbhost_skeleton.c
 create mode 100755 include/nuttx/usb/hid.h

diff --git a/ChangeLog b/ChangeLog
index 1d781751f60..f25764d6b1b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1419,3 +1419,10 @@
 	  Mass Storage Class.
 
 5.17 2011-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
+
+	* include/nuttx/usb -- rename usb_storage.h to storage.h.
+	* arch/arm/src/lpc17xx/lpc17_usbhost.c -- Add support for low-speed devices.
+	* drivers/usbhost/usbhost_skeleton.c -- Template for new class drivers
+	* include/nuttx/usb/hid.h and drivers/usbhost/usbhost_hidkbd.c -- Initial
+	  files for HID keyboard support.  These are mostly empty files on the
+	  initial checkin.
diff --git a/Documentation/NuttX.html b/Documentation/NuttX.html
index d8e5fbab596..e98e4a2fc2e 100644
--- a/Documentation/NuttX.html
+++ b/Documentation/NuttX.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: January 10, 2011</p>
+      <p>Last Updated: January 11, 2011</p>
     </td>
   </tr>
 </table>
@@ -2101,6 +2101,14 @@ buildroot-1.8 2009-12-21 &lt;spudmonkey@racsa.co.cr&gt;
 <ul><pre>
 nuttx-5.17 2011-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
+    * include/nuttx/usb -- rename usb_storage.h to storage.h.
+    * arch/arm/src/lpc17xx/lpc17_usbhost.c -- Add support for low-speed devices.
+    * drivers/usbhost/usbhost_skeleton.c -- Template for new class drivers
+    * include/nuttx/usb/hid.h and drivers/usbhost/usbhost_hidkbd.c -- Initial
+      files for HID keyboard support.  These are mostly empty files on the
+      initial checkin.
+
+
 pascal-2.1 2010-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
 buildroot-1.9 2010-xx-xx <spudmonkey@racsa.co.cr>
diff --git a/drivers/usbhost/Make.defs b/drivers/usbhost/Make.defs
index d1a34a94138..d93666bed14 100644
--- a/drivers/usbhost/Make.defs
+++ b/drivers/usbhost/Make.defs
@@ -38,5 +38,5 @@ USBHOST_CSRCS  =
 
 ifeq ($(CONFIG_USBHOST),y)
 USBHOST_CSRCS  += usbhost_registry.c usbhost_registerclass.c usbhost_findclass.c
-USBHOST_CSRCS  += usbhost_enumerate.c usbhost_storage.c
+USBHOST_CSRCS  += usbhost_enumerate.c usbhost_storage.c usbhost_hidkbd.c
 endif
diff --git a/drivers/usbhost/usbhost_hidkbd.c b/drivers/usbhost/usbhost_hidkbd.c
new file mode 100644
index 00000000000..a5d11a66d49
--- /dev/null
+++ b/drivers/usbhost/usbhost_hidkbd.c
@@ -0,0 +1,1039 @@
+/****************************************************************************
+ * drivers/usbhost/usbhost_hidkbd.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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.
+ * 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. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <semaphore.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/fs.h>
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+
+#include <nuttx/usb/usb.h>
+#include <nuttx/usb/usbhost.h>
+#include <nuttx/usb/hid.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+#  error "Worker thread support is required (CONFIG_SCHED_WORKQUEUE)"
+#endif
+
+/* Driver support ***********************************************************/
+/* This format is used to construct the /dev/sd[n] device driver path.  It
+ * defined here so that it will be used consistently in all places.
+ */
+
+#define DEV_FORMAT          "/dev/sd%c"
+#define DEV_NAMELEN         10
+
+/* Used in usbhost_connect() */
+
+#define USBHOST_IFFOUND     0x01
+#define USBHOST_BINFOUND    0x02
+#define USBHOST_BOUTFOUND   0x04
+#define USBHOST_ALLFOUND    0x07
+
+#define USBHOST_MAX_CREFS   0x7fff
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* This structure contains the internal, private state of the USB host mass
+ * storage class.
+ */
+
+struct usbhost_state_s
+{
+  /* This is the externally visible portion of the state */
+
+  struct usbhost_class_s  class;
+
+  /* This is an instance of the USB host driver bound to this class instance */
+
+  struct usbhost_driver_s *drvr;
+
+  /* The remainder of the fields are provide o the mass storage class */
+  
+  char                    sdchar;       /* Character identifying the /dev/sd[n] device */
+  volatile bool           disconnected; /* TRUE: Device has been disconnected */
+  int16_t                 crefs;        /* Reference count on the driver instance */
+  sem_t                   exclsem;      /* Used to maintain mutual exclusive access */
+  struct work_s           work;         /* For interacting with the worker thread */
+  FAR uint8_t            *tdbuffer;     /* The allocated transfer descriptor buffer */
+  size_t                  tdbuflen;     /* Size of the allocated transfer buffer */
+  usbhost_ep_t            epin;         /* IN endpoint */
+  usbhost_ep_t            epout;        /* OUT endpoint */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Semaphores */
+
+static void usbhost_takesem(sem_t *sem);
+#define usbhost_givesem(s) sem_post(s);
+
+/* Memory allocation services */
+
+static inline FAR struct usbhost_state_s *usbhost_allocclass(void);
+static inline void usbhost_freeclass(FAR struct usbhost_state_s *class);
+
+/* Device name management */
+
+static int usbhost_allocdevno(FAR struct usbhost_state_s *priv);
+static void usbhost_freedevno(FAR struct usbhost_state_s *priv);
+static inline void usbhost_mkdevname(FAR struct usbhost_state_s *priv, char *devname);
+
+/* Worker thread actions */
+
+static void usbhost_destroy(FAR void *arg);
+static inline int usbhost_cfgdesc(FAR struct usbhost_state_s *priv,
+                                  FAR const uint8_t *configdesc, int desclen,
+                                  uint8_t funcaddr);
+static inline int usbhost_devinit(FAR struct usbhost_state_s *priv);
+
+/* (Little Endian) Data helpers */
+
+static inline uint16_t usbhost_getle16(const uint8_t *val);
+static inline void usbhost_putle16(uint8_t *dest, uint16_t val);
+static inline uint32_t usbhost_getle32(const uint8_t *val);
+static void usbhost_putle32(uint8_t *dest, uint32_t val);
+
+/* Transfer descriptor memory management */
+
+static inline int usbhost_tdalloc(FAR struct usbhost_state_s *priv);
+static inline int usbhost_tdfree(FAR struct usbhost_state_s *priv);
+
+/* struct usbhost_registry_s methods */
+ 
+static struct usbhost_class_s *usbhost_create(FAR struct usbhost_driver_s *drvr,
+                                              FAR const struct usbhost_id_s *id);
+
+/* struct usbhost_class_s methods */
+
+static int usbhost_connect(FAR struct usbhost_class_s *class,
+                           FAR const uint8_t *configdesc, int desclen,
+                           uint8_t funcaddr);
+static int usbhost_disconnected(FAR struct usbhost_class_s *class);
+
+/* Driver methods -- depend upon the type of NuttX driver interface exported */
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This structure provides the registry entry ID informatino that will  be 
+ * used to associate the USB host mass storage class to a connected USB
+ * device.
+ */
+
+static const const struct usbhost_id_s g_id =
+{
+  USB_CLASS_HID,            /* base     */
+  USBHID_SUBCLASS_BOOTIF,   /* subclass */
+  USBHID_PROTOCOL_KEYBOARD, /* proto    */
+  0,                        /* vid      */
+  0                         /* pid      */
+};
+
+/* This is the USB host storage class's registry entry */
+
+static struct usbhost_registry_s g_skeleton =
+{
+  NULL,                    /* flink     */
+  usbhost_create,          /* create    */
+  1,                       /* nids      */
+  &g_id                    /* id[]      */
+};
+
+/* This is a bitmap that is used to allocate device names /dev/sda-z. */
+
+static uint32_t g_devinuse;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_takesem
+ *
+ * Description:
+ *   This is just a wrapper to handle the annoying behavior of semaphore
+ *   waits that return due to the receipt of a signal.
+ *
+ ****************************************************************************/
+
+static void usbhost_takesem(sem_t *sem)
+{
+  /* Take the semaphore (perhaps waiting) */
+
+  while (sem_wait(sem) != 0)
+    {
+      /* The only case that an error should occr here is if the wait was
+       * awakened by a signal.
+       */
+
+      ASSERT(errno == EINTR);
+    }
+}
+
+/****************************************************************************
+ * Name: usbhost_allocclass
+ *
+ * Description:
+ *   This is really part of the logic that implements the create() method
+ *   of struct usbhost_registry_s.  This function allocates memory for one
+ *   new class instance.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Values:
+ *   On success, this function will return a non-NULL instance of struct
+ *   usbhost_class_s.  NULL is returned on failure; this function will
+ *   will fail only if there are insufficient resources to create another
+ *   USB host class instance.
+ *
+ ****************************************************************************/
+
+static inline FAR struct usbhost_state_s *usbhost_allocclass(void)
+{
+  FAR struct usbhost_state_s *priv;
+
+  DEBUGASSERT(!up_interrupt_context());
+  priv = (FAR struct usbhost_state_s *)malloc(sizeof(struct usbhost_state_s));
+  uvdbg("Allocated: %p\n", priv);;
+  return priv;
+}
+
+/****************************************************************************
+ * Name: usbhost_freeclass
+ *
+ * Description:
+ *   Free a class instance previously allocated by usbhost_allocclass().
+ *
+ * Input Parameters:
+ *   class - A reference to the class instance to be freed.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline void usbhost_freeclass(FAR struct usbhost_state_s *class)
+{
+  DEBUGASSERT(class != NULL);
+
+  /* Free the class instance (calling sched_free() in case we are executing
+   * from an interrupt handler.
+   */
+
+  uvdbg("Freeing: %p\n", class);;
+  free(class);
+}
+
+/****************************************************************************
+ * Name: Device name management
+ *
+ * Description:
+ *   Some tiny functions to coordinate management of device names.
+ *
+ ****************************************************************************/
+
+static int usbhost_allocdevno(FAR struct usbhost_state_s *priv)
+{
+  irqstate_t flags;
+  int devno;
+
+  flags = irqsave();
+  for (devno = 0; devno < 26; devno++)
+    {
+      uint32_t bitno = 1 << devno;
+      if ((g_devinuse & bitno) == 0)
+        {
+          g_devinuse |= bitno;
+          priv->sdchar = 'a' + devno;
+          irqrestore(flags);
+          return OK;
+        }
+    }
+
+  irqrestore(flags);
+  return -EMFILE;
+}
+
+static void usbhost_freedevno(FAR struct usbhost_state_s *priv)
+{
+  int devno = 'a' - priv->sdchar;
+
+  if (devno >= 0 && devno < 26)
+    {
+      irqstate_t flags = irqsave();
+      g_devinuse &= ~(1 << devno);
+      irqrestore(flags);
+    }
+}
+
+static inline void usbhost_mkdevname(FAR struct usbhost_state_s *priv, char *devname)
+{
+  (void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->sdchar);
+}
+
+/****************************************************************************
+ * Name: usbhost_destroy
+ *
+ * Description:
+ *   The USB device has been disconnected and the refernce count on the USB
+ *   host class instance has gone to 1.. Time to destroy the USB host class
+ *   instance.
+ *
+ * Input Parameters:
+ *   arg - A reference to the class instance to be destroyed.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_destroy(FAR void *arg)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)arg;
+
+  DEBUGASSERT(priv != NULL);
+  uvdbg("crefs: %d\n", priv->crefs);
+ 
+  /* Unregister the driver */
+
+  /* Release the device name used by this connection */
+
+  usbhost_freedevno(priv);
+
+  /* Free the endpoints */
+
+  /* Free any transfer buffers */
+
+  /* Destroy the semaphores */
+
+  /* Disconnect the USB host device */
+
+  DRVR_DISCONNECT(priv->drvr);
+
+  /* And free the class instance.  Hmmm.. this may execute on the worker
+   * thread and the work structure is part of what is getting freed.  That
+   * should be okay because once the work contained is removed from the
+   * queue, it should not longer be accessed by the worker thread.
+   */
+
+  usbhost_freeclass(priv);
+}
+
+/****************************************************************************
+ * Name: usbhost_cfgdesc
+ *
+ * Description:
+ *   This function implements the connect() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to provide the device's configuration
+ *   descriptor to the class so that the class may initialize properly
+ *
+ * Input Parameters:
+ *   priv - The USB host class instance.
+ *   configdesc - A pointer to a uint8_t buffer container the configuration descripor.
+ *   desclen - The length in bytes of the configuration descriptor.
+ *   funcaddr - The USB address of the function containing the endpoint that EP0
+ *     controls
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value is
+ *   returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function will *not* be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_cfgdesc(FAR struct usbhost_state_s *priv,
+                                  FAR const uint8_t *configdesc, int desclen,
+                                  uint8_t funcaddr)
+{
+  FAR struct usb_cfgdesc_s *cfgdesc;
+  FAR struct usb_desc_s *desc;
+  FAR struct usbhost_epdesc_s bindesc;
+  FAR struct usbhost_epdesc_s boutdesc;
+  int remaining;
+  uint8_t found = 0;
+  int ret;
+
+  DEBUGASSERT(priv != NULL && 
+              configdesc != NULL &&
+              desclen >= sizeof(struct usb_cfgdesc_s));
+  
+  /* Verify that we were passed a configuration descriptor */
+
+  cfgdesc = (FAR struct usb_cfgdesc_s *)configdesc;
+  if (cfgdesc->type != USB_DESC_TYPE_CONFIG)
+    {
+      return -EINVAL;
+    }
+
+  /* Get the total length of the configuration descriptor (little endian).
+   * It might be a good check to get the number of interfaces here too.
+  */
+
+  remaining = (int)usbhost_getle16(cfgdesc->totallen);
+
+  /* Skip to the next entry descriptor */
+
+  configdesc += cfgdesc->len;
+  remaining  -= cfgdesc->len;
+
+  /* Loop where there are more dscriptors to examine */
+
+  while (remaining >= sizeof(struct usb_desc_s))
+    {
+      /* What is the next descriptor? */
+
+      desc = (FAR struct usb_desc_s *)configdesc;
+      switch (desc->type)
+        {
+        /* Interface descriptor. We really should get the number of endpoints
+         * from this descriptor too.
+         */
+
+        case USB_DESC_TYPE_INTERFACE:
+          {
+            DEBUGASSERT(remaining >= USB_SIZEOF_IFDESC);
+            if ((found & USBHOST_IFFOUND) != 0)
+              {
+                /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                return -ENOSYS;
+              }
+            found |= USBHOST_IFFOUND;
+          }
+          break;
+
+        /* Endpoint descriptor.  We expect two bulk endpoints, an IN and an OUT */
+        case USB_DESC_TYPE_ENDPOINT:
+          {
+            FAR struct usb_epdesc_s *epdesc = (FAR struct usb_epdesc_s *)configdesc;
+            DEBUGASSERT(remaining >= USB_SIZEOF_EPDESC);
+
+            /* Check for a bulk endpoint.  We only support the bulk-only
+             * protocol so I suppose anything else should really be an error.
+             */
+
+            if ((epdesc->attr & USB_EP_ATTR_XFERTYPE_MASK) == USB_EP_ATTR_XFER_BULK)
+              {
+                /* Yes.. it is a bulk endpoint.  IN or OUT? */
+
+                if (USB_ISEPOUT(epdesc->addr))
+                  {
+                    /* It is an OUT bulk endpoint.  There should be only one bulk OUT endpoint. */
+
+                    if ((found & USBHOST_BOUTFOUND) != 0)
+                      {
+                        /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                        return -EINVAL;
+                      }
+                    found |= USBHOST_BOUTFOUND;
+
+                    /* Save the bulk OUT endpoint information */
+
+                    boutdesc.addr         = epdesc->addr & USB_EP_ADDR_NUMBER_MASK;
+                    boutdesc.in           = false;
+                    boutdesc.funcaddr     = funcaddr;
+                    boutdesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize);
+                    uvdbg("Bulk OUT EP addr:%d mxpacketsize:%d\n",
+                          boutdesc.addr, boutdesc.mxpacketsize);
+                  }
+                else
+                  {
+                    /* It is an IN bulk endpoint.  There should be only one bulk IN endpoint. */
+
+                    if ((found & USBHOST_BINFOUND) != 0)
+                      {
+                        /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                        return -EINVAL;
+                      }
+                    found |= USBHOST_BINFOUND;
+
+                    /* Save the bulk IN endpoint information */
+                    
+                    bindesc.addr        = epdesc->addr & USB_EP_ADDR_NUMBER_MASK;
+                    bindesc.in           = 1;
+                    bindesc.funcaddr     = funcaddr;
+                    bindesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize);
+                    uvdbg("Bulk IN EP addr:%d mxpacketsize:%d\n",
+                          bindesc.addr, bindesc.mxpacketsize);
+                  }
+              }
+          }
+          break;
+
+        /* Other descriptors are just ignored for now */
+
+        default:
+          break;
+        }
+
+      /* Increment the address of the next descriptor */
+ 
+      configdesc += desc->len;
+      remaining  -= desc->len;
+    }
+
+  /* Sanity checking... did we find all of things that we need? Hmmm..  I wonder..
+   * can we work read-only or write-only if only one bulk endpoint found?
+   */
+    
+  if (found != USBHOST_ALLFOUND)
+    {
+      ulldbg("ERROR: Found IF:%s BIN:%s BOUT:%s\n",
+             (found & USBHOST_IFFOUND) != 0  ? "YES" : "NO",
+             (found & USBHOST_BINFOUND) != 0 ? "YES" : "NO",
+             (found & USBHOST_BOUTFOUND) != 0 ? "YES" : "NO");
+      return -EINVAL;
+    }
+
+  /* We are good... Allocate the endpoints */
+
+  ret = DRVR_EPALLOC(priv->drvr, &boutdesc, &priv->epout);
+  if (ret != OK)
+    {
+      udbg("ERROR: Failed to allocate Bulk OUT endpoint\n");
+      return ret;
+    }
+
+  ret = DRVR_EPALLOC(priv->drvr, &bindesc, &priv->epin);
+  if (ret != OK)
+    {
+      udbg("ERROR: Failed to allocate Bulk IN endpoint\n");
+      (void)DRVR_EPFREE(priv->drvr, priv->epout);
+      return ret;
+    }
+
+  ullvdbg("Endpoints allocated\n");
+  return OK;
+}
+
+/****************************************************************************
+ * Name: usbhost_devinit
+ *
+ * Description:
+ *   The USB device has been successfully connected.  This completes the
+ *   initialization operations.  It is first called after the
+ *   configuration descriptor has been received.
+ *
+ *   This function is called from the connect() method.  This function always
+ *   executes on the thread of the caller of connect().
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline int usbhost_devinit(FAR struct usbhost_state_s *priv)
+{
+  int ret;
+
+  /* Set aside a transfer buffer for exclusive use by the class driver */
+
+  /* Increment the reference count.  This will prevent usbhost_destroy() from
+   * being called asynchronously if the device is removed.
+   */
+
+  priv->crefs++;
+  DEBUGASSERT(priv->crefs == 2);
+
+  /* Configure the device */
+
+  /* Register the driver */
+
+  if (ret == OK)
+    {
+      char devname[DEV_NAMELEN];
+
+      uvdbg("Register block driver\n");
+      usbhost_mkdevname(priv, devname);
+      // ret = register_blockdriver(devname, &g_bops, 0, priv);
+    }
+
+  /* Check if we successfully initialized. We now have to be concerned
+   * about asynchronous modification of crefs because the block
+   * driver has been registerd.
+   */
+
+  if (ret == OK)
+    {
+      usbhost_takesem(&priv->exclsem);
+      DEBUGASSERT(priv->crefs >= 2);
+
+      /* Handle a corner case where (1) open() has been called so the
+       * reference count is > 2, but the device has been disconnected.
+       * In this case, the class instance needs to persist until close()
+       * is called.
+       */
+
+      if (priv->crefs <= 2 && priv->disconnected)
+        {
+          /* We don't have to give the semaphore because it will be
+           * destroyed when usb_destroy is called.
+           */
+  
+          ret = -ENODEV;
+        }
+      else
+        {
+          /* Ready for normal operation as a block device driver */
+
+          uvdbg("Successfully initialized\n");
+          priv->crefs--;
+          usbhost_givesem(&priv->exclsem);
+        }
+    }
+
+  /* Disconnect on any errors detected during volume initialization */
+
+  if (ret != OK)
+    {
+      udbg("ERROR! Aborting: %d\n", ret);
+      usbhost_destroy(priv);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: usbhost_getle16
+ *
+ * Description:
+ *   Get a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   val - A pointer to the first byte of the little endian value.
+ *
+ * Returned Values:
+ *   A uint16_t representing the whole 16-bit integer value
+ *
+ ****************************************************************************/
+
+static inline uint16_t usbhost_getle16(const uint8_t *val)
+{
+  return (uint16_t)val[1] << 8 | (uint16_t)val[0];
+}
+
+/****************************************************************************
+ * Name: usbhost_putle16
+ *
+ * Description:
+ *   Put a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 16-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_putle16(uint8_t *dest, uint16_t val)
+{
+  dest[0] = val & 0xff; /* Little endian means LS byte first in byte stream */
+  dest[1] = val >> 8;
+}
+
+/****************************************************************************
+ * Name: usbhost_getle32
+ *
+ * Description:
+ *   Get a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the big endian value.
+ *   val - The 32-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline uint32_t usbhost_getle32(const uint8_t *val)
+{
+ /* Little endian means LS halfword first in byte stream */
+
+  return (uint32_t)usbhost_getle16(&val[2]) << 16 | (uint32_t)usbhost_getle16(val);
+}
+
+/****************************************************************************
+ * Name: usbhost_putle32
+ *
+ * Description:
+ *   Put a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 32-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_putle32(uint8_t *dest, uint32_t val)
+{
+  /* Little endian means LS halfword first in byte stream */
+
+  usbhost_putle16(dest, (uint16_t)(val & 0xffff));
+  usbhost_putle16(dest+2, (uint16_t)(val >> 16));
+}
+
+/****************************************************************************
+ * Name: usbhost_tdalloc
+ *
+ * Description:
+ *   Allocate transfer descriptor memory.
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   On sucess, zero (OK) is returned.  On failure, an negated errno value
+ *   is returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_tdalloc(FAR struct usbhost_state_s *priv)
+{
+  DEBUGASSERT(priv && priv->tdbuffer == NULL);
+  return DRVR_ALLOC(priv->drvr, &priv->tdbuffer, &priv->tdbuflen);
+}
+
+/****************************************************************************
+ * Name: usbhost_tdfree
+ *
+ * Description:
+ *   Free transfer descriptor memory.
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   On sucess, zero (OK) is returned.  On failure, an negated errno value
+ *   is returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_tdfree(FAR struct usbhost_state_s *priv)
+{
+  int result = OK;
+  DEBUGASSERT(priv);
+
+  if (priv->tdbuffer)
+    {
+      DEBUGASSERT(priv->drvr);
+      result         = DRVR_FREE(priv->drvr, priv->tdbuffer);
+      priv->tdbuffer = NULL;
+      priv->tdbuflen = 0;
+    }
+  return result;
+}
+
+/****************************************************************************
+ * struct usbhost_registry_s methods
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_create
+ *
+ * Description:
+ *   This function implements the create() method of struct usbhost_registry_s. 
+ *   The create() method is a callback into the class implementation.  It is
+ *   used to (1) create a new instance of the USB host class state and to (2)
+ *   bind a USB host driver "session" to the class instance.  Use of this
+ *   create() method will support environments where there may be multiple
+ *   USB ports and multiple USB devices simultaneously connected.
+ *
+ * Input Parameters:
+ *   drvr - An instance of struct usbhost_driver_s that the class
+ *     implementation will "bind" to its state structure and will
+ *     subsequently use to communicate with the USB host driver.
+ *   id - In the case where the device supports multiple base classes,
+ *     subclasses, or protocols, this specifies which to configure for.
+ *
+ * Returned Values:
+ *   On success, this function will return a non-NULL instance of struct
+ *   usbhost_class_s that can be used by the USB host driver to communicate
+ *   with the USB host class.  NULL is returned on failure; this function
+ *   will fail only if the drvr input parameter is NULL or if there are
+ *   insufficient resources to create another USB host class instance.
+ *
+ ****************************************************************************/
+
+static FAR struct usbhost_class_s *usbhost_create(FAR struct usbhost_driver_s *drvr,
+                                                  FAR const struct usbhost_id_s *id)
+{
+  FAR struct usbhost_state_s *priv;
+
+  /* Allocate a USB host class instance */
+
+  priv = usbhost_allocclass();
+  if (priv)
+    {
+      /* Initialize the allocated storage class instance */
+
+      memset(priv, 0, sizeof(struct usbhost_state_s));
+
+      /* Assign a device number to this class instance */
+
+      if (usbhost_allocdevno(priv) == OK)
+        {
+         /* Initialize class method function pointers */
+
+          priv->class.connect      = usbhost_connect;
+          priv->class.disconnected = usbhost_disconnected;
+
+          /* The initial reference count is 1... One reference is held by the driver */
+
+          priv->crefs              = 1;
+
+          /* Initialize semphores (this works okay in the interrupt context) */
+
+          sem_init(&priv->exclsem, 0, 1);
+
+          /* Bind the driver to the storage class instance */
+
+          priv->drvr               = drvr;
+
+          /* NOTE: We do not yet know the geometry of the USB mass storage device */
+ 
+          /* Return the instance of the USB mass storage class */
+ 
+          return &priv->class;
+        }
+    }
+
+  /* An error occurred. Free the allocation and return NULL on all failures */
+
+  if (priv)
+    {
+      usbhost_freeclass(priv);
+    }
+  return NULL;
+}
+
+/****************************************************************************
+ * struct usbhost_class_s methods
+ ****************************************************************************/
+/****************************************************************************
+ * Name: usbhost_connect
+ *
+ * Description:
+ *   This function implements the connect() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to provide the device's configuration
+ *   descriptor to the class so that the class may initialize properly
+ *
+ * Input Parameters:
+ *   class - The USB host class entry previously obtained from a call to create().
+ *   configdesc - A pointer to a uint8_t buffer container the configuration descripor.
+ *   desclen - The length in bytes of the configuration descriptor.
+ *   funcaddr - The USB address of the function containing the endpoint that EP0
+ *     controls
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value is
+ *   returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function will *not* be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static int usbhost_connect(FAR struct usbhost_class_s *class,
+                           FAR const uint8_t *configdesc, int desclen,
+                           uint8_t funcaddr)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)class;
+  int ret;
+
+  DEBUGASSERT(priv != NULL && 
+              configdesc != NULL &&
+              desclen >= sizeof(struct usb_cfgdesc_s));
+
+  /* Parse the configuration descriptor to get the endpoints */
+
+  ret = usbhost_cfgdesc(priv, configdesc, desclen, funcaddr);
+  if (ret != OK)
+    {
+      udbg("usbhost_cfgdesc() failed: %d\n", ret);
+    }
+  else
+    {
+      /* Now configure the device and register the NuttX driver */
+
+      ret = usbhost_devinit(priv);
+      if (ret != OK)
+        {
+          udbg("usbhost_devinit() failed: %d\n", ret);
+        }
+    }
+ 
+  return ret;
+}
+
+/****************************************************************************
+ * Name: usbhost_disconnected
+ *
+ * Description:
+ *   This function implements the disconnected() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to inform the class that the USB device has
+ *   been disconnected.
+ *
+ * Input Parameters:
+ *   class - The USB host class entry previously obtained from a call to
+ *     create().
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value
+ *   is returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function may be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static int usbhost_disconnected(struct usbhost_class_s *class)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)class;
+  irqstate_t flags;
+
+  DEBUGASSERT(priv != NULL);
+
+  /* Set an indication to any users of the mass storage device that the device
+   * is no longer available.
+   */
+
+  flags              = irqsave();
+  priv->disconnected = true;
+
+  /* Now check the number of references on the class instance.  If it is one,
+   * then we can free the class instance now.  Otherwise, we will have to
+   * wait until the holders of the references free them by closing the
+   * block driver.
+   */
+
+  ullvdbg("crefs: %d\n", priv->crefs);
+  if (priv->crefs == 1)
+    {
+      /* Destroy the class instance.  If we are executing from an interrupt
+       * handler, then defer the destruction to the worker thread.
+       * Otherwise, destroy the instance now.
+       */
+
+      if (up_interrupt_context())
+        {
+          /* Destroy the instance on the worker thread. */
+
+          uvdbg("Queuing destruction: worker %p->%p\n", priv->work.worker, usbhost_destroy);
+          DEBUGASSERT(priv->work.worker == NULL);
+          (void)work_queue(&priv->work, usbhost_destroy, priv, 0);
+       }
+      else
+        {
+          /* Do the work now */
+
+          usbhost_destroy(priv);
+        }
+    }
+
+  irqrestore(flags);  
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_skelinit
+ *
+ * Description:
+ *   Initialize the USB storage class.  This function should be called
+ *   be platform-specific code in order to initialize and register support
+ *   for the USB host storage class.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Values:
+ *   On success this function will return zero (OK);  A negated errno value
+ *   will be returned on failure.
+ *
+ ****************************************************************************/
+
+int usbhost_skelinit(void)
+{
+  /* Perform any one-time initialization of the class implementation */
+
+  /* Advertise our availability to support (certain) devices */
+
+  return usbhost_registerclass(&g_skeleton);
+}
+
diff --git a/drivers/usbhost/usbhost_skeleton.c b/drivers/usbhost/usbhost_skeleton.c
new file mode 100644
index 00000000000..ee1d78e4a07
--- /dev/null
+++ b/drivers/usbhost/usbhost_skeleton.c
@@ -0,0 +1,1038 @@
+/****************************************************************************
+ * drivers/usbhost/usbhost_skeleton.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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.
+ * 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. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <semaphore.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/fs.h>
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+
+#include <nuttx/usb/usb.h>
+#include <nuttx/usb/usbhost.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+#  error "Worker thread support is required (CONFIG_SCHED_WORKQUEUE)"
+#endif
+
+/* Driver support ***********************************************************/
+/* This format is used to construct the /dev/sd[n] device driver path.  It
+ * defined here so that it will be used consistently in all places.
+ */
+
+#define DEV_FORMAT          "/dev/sd%c"
+#define DEV_NAMELEN         10
+
+/* Used in usbhost_connect() */
+
+#define USBHOST_IFFOUND     0x01
+#define USBHOST_BINFOUND    0x02
+#define USBHOST_BOUTFOUND   0x04
+#define USBHOST_ALLFOUND    0x07
+
+#define USBHOST_MAX_CREFS   0x7fff
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* This structure contains the internal, private state of the USB host mass
+ * storage class.
+ */
+
+struct usbhost_state_s
+{
+  /* This is the externally visible portion of the state */
+
+  struct usbhost_class_s  class;
+
+  /* This is an instance of the USB host driver bound to this class instance */
+
+  struct usbhost_driver_s *drvr;
+
+  /* The remainder of the fields are provide o the mass storage class */
+  
+  char                    sdchar;       /* Character identifying the /dev/sd[n] device */
+  volatile bool           disconnected; /* TRUE: Device has been disconnected */
+  int16_t                 crefs;        /* Reference count on the driver instance */
+  sem_t                   exclsem;      /* Used to maintain mutual exclusive access */
+  struct work_s           work;         /* For interacting with the worker thread */
+  FAR uint8_t            *tdbuffer;     /* The allocated transfer descriptor buffer */
+  size_t                  tdbuflen;     /* Size of the allocated transfer buffer */
+  usbhost_ep_t            epin;         /* IN endpoint */
+  usbhost_ep_t            epout;        /* OUT endpoint */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Semaphores */
+
+static void usbhost_takesem(sem_t *sem);
+#define usbhost_givesem(s) sem_post(s);
+
+/* Memory allocation services */
+
+static inline FAR struct usbhost_state_s *usbhost_allocclass(void);
+static inline void usbhost_freeclass(FAR struct usbhost_state_s *class);
+
+/* Device name management */
+
+static int usbhost_allocdevno(FAR struct usbhost_state_s *priv);
+static void usbhost_freedevno(FAR struct usbhost_state_s *priv);
+static inline void usbhost_mkdevname(FAR struct usbhost_state_s *priv, char *devname);
+
+/* Worker thread actions */
+
+static void usbhost_destroy(FAR void *arg);
+static inline int usbhost_cfgdesc(FAR struct usbhost_state_s *priv,
+                                  FAR const uint8_t *configdesc, int desclen,
+                                  uint8_t funcaddr);
+static inline int usbhost_devinit(FAR struct usbhost_state_s *priv);
+
+/* (Little Endian) Data helpers */
+
+static inline uint16_t usbhost_getle16(const uint8_t *val);
+static inline void usbhost_putle16(uint8_t *dest, uint16_t val);
+static inline uint32_t usbhost_getle32(const uint8_t *val);
+static void usbhost_putle32(uint8_t *dest, uint32_t val);
+
+/* Transfer descriptor memory management */
+
+static inline int usbhost_tdalloc(FAR struct usbhost_state_s *priv);
+static inline int usbhost_tdfree(FAR struct usbhost_state_s *priv);
+
+/* struct usbhost_registry_s methods */
+ 
+static struct usbhost_class_s *usbhost_create(FAR struct usbhost_driver_s *drvr,
+                                              FAR const struct usbhost_id_s *id);
+
+/* struct usbhost_class_s methods */
+
+static int usbhost_connect(FAR struct usbhost_class_s *class,
+                           FAR const uint8_t *configdesc, int desclen,
+                           uint8_t funcaddr);
+static int usbhost_disconnected(FAR struct usbhost_class_s *class);
+
+/* Driver methods -- depend upon the type of NuttX driver interface exported */
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This structure provides the registry entry ID informatino that will  be 
+ * used to associate the USB host mass storage class to a connected USB
+ * device.
+ */
+
+static const const struct usbhost_id_s g_id =
+{
+  0,  /* base -- Must be one of the USB_CLASS_* definitions in usb.h */
+  0,  /* subclass -- depends on the device */
+  0,  /* proto -- depends on the device    */
+  0,  /* vid      */
+  0   /* pid      */
+};
+
+/* This is the USB host storage class's registry entry */
+
+static struct usbhost_registry_s g_skeleton =
+{
+  NULL,                   /* flink    */
+  usbhost_create,         /* create   */
+  1,                      /* nids     */
+  &g_id                   /* id[]     */
+};
+
+/* This is a bitmap that is used to allocate device names /dev/sda-z. */
+
+static uint32_t g_devinuse;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_takesem
+ *
+ * Description:
+ *   This is just a wrapper to handle the annoying behavior of semaphore
+ *   waits that return due to the receipt of a signal.
+ *
+ ****************************************************************************/
+
+static void usbhost_takesem(sem_t *sem)
+{
+  /* Take the semaphore (perhaps waiting) */
+
+  while (sem_wait(sem) != 0)
+    {
+      /* The only case that an error should occr here is if the wait was
+       * awakened by a signal.
+       */
+
+      ASSERT(errno == EINTR);
+    }
+}
+
+/****************************************************************************
+ * Name: usbhost_allocclass
+ *
+ * Description:
+ *   This is really part of the logic that implements the create() method
+ *   of struct usbhost_registry_s.  This function allocates memory for one
+ *   new class instance.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Values:
+ *   On success, this function will return a non-NULL instance of struct
+ *   usbhost_class_s.  NULL is returned on failure; this function will
+ *   will fail only if there are insufficient resources to create another
+ *   USB host class instance.
+ *
+ ****************************************************************************/
+
+static inline FAR struct usbhost_state_s *usbhost_allocclass(void)
+{
+  FAR struct usbhost_state_s *priv;
+
+  DEBUGASSERT(!up_interrupt_context());
+  priv = (FAR struct usbhost_state_s *)malloc(sizeof(struct usbhost_state_s));
+  uvdbg("Allocated: %p\n", priv);;
+  return priv;
+}
+
+/****************************************************************************
+ * Name: usbhost_freeclass
+ *
+ * Description:
+ *   Free a class instance previously allocated by usbhost_allocclass().
+ *
+ * Input Parameters:
+ *   class - A reference to the class instance to be freed.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline void usbhost_freeclass(FAR struct usbhost_state_s *class)
+{
+  DEBUGASSERT(class != NULL);
+
+  /* Free the class instance (calling sched_free() in case we are executing
+   * from an interrupt handler.
+   */
+
+  uvdbg("Freeing: %p\n", class);;
+  free(class);
+}
+
+/****************************************************************************
+ * Name: Device name management
+ *
+ * Description:
+ *   Some tiny functions to coordinate management of device names.
+ *
+ ****************************************************************************/
+
+static int usbhost_allocdevno(FAR struct usbhost_state_s *priv)
+{
+  irqstate_t flags;
+  int devno;
+
+  flags = irqsave();
+  for (devno = 0; devno < 26; devno++)
+    {
+      uint32_t bitno = 1 << devno;
+      if ((g_devinuse & bitno) == 0)
+        {
+          g_devinuse |= bitno;
+          priv->sdchar = 'a' + devno;
+          irqrestore(flags);
+          return OK;
+        }
+    }
+
+  irqrestore(flags);
+  return -EMFILE;
+}
+
+static void usbhost_freedevno(FAR struct usbhost_state_s *priv)
+{
+  int devno = 'a' - priv->sdchar;
+
+  if (devno >= 0 && devno < 26)
+    {
+      irqstate_t flags = irqsave();
+      g_devinuse &= ~(1 << devno);
+      irqrestore(flags);
+    }
+}
+
+static inline void usbhost_mkdevname(FAR struct usbhost_state_s *priv, char *devname)
+{
+  (void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->sdchar);
+}
+
+/****************************************************************************
+ * Name: usbhost_destroy
+ *
+ * Description:
+ *   The USB device has been disconnected and the refernce count on the USB
+ *   host class instance has gone to 1.. Time to destroy the USB host class
+ *   instance.
+ *
+ * Input Parameters:
+ *   arg - A reference to the class instance to be destroyed.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_destroy(FAR void *arg)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)arg;
+
+  DEBUGASSERT(priv != NULL);
+  uvdbg("crefs: %d\n", priv->crefs);
+ 
+  /* Unregister the driver */
+
+  /* Release the device name used by this connection */
+
+  usbhost_freedevno(priv);
+
+  /* Free the endpoints */
+
+  /* Free any transfer buffers */
+
+  /* Destroy the semaphores */
+
+  /* Disconnect the USB host device */
+
+  DRVR_DISCONNECT(priv->drvr);
+
+  /* And free the class instance.  Hmmm.. this may execute on the worker
+   * thread and the work structure is part of what is getting freed.  That
+   * should be okay because once the work contained is removed from the
+   * queue, it should not longer be accessed by the worker thread.
+   */
+
+  usbhost_freeclass(priv);
+}
+
+/****************************************************************************
+ * Name: usbhost_cfgdesc
+ *
+ * Description:
+ *   This function implements the connect() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to provide the device's configuration
+ *   descriptor to the class so that the class may initialize properly
+ *
+ * Input Parameters:
+ *   priv - The USB host class instance.
+ *   configdesc - A pointer to a uint8_t buffer container the configuration descripor.
+ *   desclen - The length in bytes of the configuration descriptor.
+ *   funcaddr - The USB address of the function containing the endpoint that EP0
+ *     controls
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value is
+ *   returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function will *not* be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_cfgdesc(FAR struct usbhost_state_s *priv,
+                                  FAR const uint8_t *configdesc, int desclen,
+                                  uint8_t funcaddr)
+{
+  FAR struct usb_cfgdesc_s *cfgdesc;
+  FAR struct usb_desc_s *desc;
+  FAR struct usbhost_epdesc_s bindesc;
+  FAR struct usbhost_epdesc_s boutdesc;
+  int remaining;
+  uint8_t found = 0;
+  int ret;
+
+  DEBUGASSERT(priv != NULL && 
+              configdesc != NULL &&
+              desclen >= sizeof(struct usb_cfgdesc_s));
+  
+  /* Verify that we were passed a configuration descriptor */
+
+  cfgdesc = (FAR struct usb_cfgdesc_s *)configdesc;
+  if (cfgdesc->type != USB_DESC_TYPE_CONFIG)
+    {
+      return -EINVAL;
+    }
+
+  /* Get the total length of the configuration descriptor (little endian).
+   * It might be a good check to get the number of interfaces here too.
+  */
+
+  remaining = (int)usbhost_getle16(cfgdesc->totallen);
+
+  /* Skip to the next entry descriptor */
+
+  configdesc += cfgdesc->len;
+  remaining  -= cfgdesc->len;
+
+  /* Loop where there are more dscriptors to examine */
+
+  while (remaining >= sizeof(struct usb_desc_s))
+    {
+      /* What is the next descriptor? */
+
+      desc = (FAR struct usb_desc_s *)configdesc;
+      switch (desc->type)
+        {
+        /* Interface descriptor. We really should get the number of endpoints
+         * from this descriptor too.
+         */
+
+        case USB_DESC_TYPE_INTERFACE:
+          {
+            DEBUGASSERT(remaining >= USB_SIZEOF_IFDESC);
+            if ((found & USBHOST_IFFOUND) != 0)
+              {
+                /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                return -ENOSYS;
+              }
+            found |= USBHOST_IFFOUND;
+          }
+          break;
+
+        /* Endpoint descriptor.  We expect two bulk endpoints, an IN and an OUT */
+        case USB_DESC_TYPE_ENDPOINT:
+          {
+            FAR struct usb_epdesc_s *epdesc = (FAR struct usb_epdesc_s *)configdesc;
+            DEBUGASSERT(remaining >= USB_SIZEOF_EPDESC);
+
+            /* Check for a bulk endpoint.  We only support the bulk-only
+             * protocol so I suppose anything else should really be an error.
+             */
+
+            if ((epdesc->attr & USB_EP_ATTR_XFERTYPE_MASK) == USB_EP_ATTR_XFER_BULK)
+              {
+                /* Yes.. it is a bulk endpoint.  IN or OUT? */
+
+                if (USB_ISEPOUT(epdesc->addr))
+                  {
+                    /* It is an OUT bulk endpoint.  There should be only one bulk OUT endpoint. */
+
+                    if ((found & USBHOST_BOUTFOUND) != 0)
+                      {
+                        /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                        return -EINVAL;
+                      }
+                    found |= USBHOST_BOUTFOUND;
+
+                    /* Save the bulk OUT endpoint information */
+
+                    boutdesc.addr         = epdesc->addr & USB_EP_ADDR_NUMBER_MASK;
+                    boutdesc.in           = false;
+                    boutdesc.funcaddr     = funcaddr;
+                    boutdesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize);
+                    uvdbg("Bulk OUT EP addr:%d mxpacketsize:%d\n",
+                          boutdesc.addr, boutdesc.mxpacketsize);
+                  }
+                else
+                  {
+                    /* It is an IN bulk endpoint.  There should be only one bulk IN endpoint. */
+
+                    if ((found & USBHOST_BINFOUND) != 0)
+                      {
+                        /* Oops.. more than one interface.  We don't know what to do with this. */
+
+                        return -EINVAL;
+                      }
+                    found |= USBHOST_BINFOUND;
+
+                    /* Save the bulk IN endpoint information */
+                    
+                    bindesc.addr        = epdesc->addr & USB_EP_ADDR_NUMBER_MASK;
+                    bindesc.in           = 1;
+                    bindesc.funcaddr     = funcaddr;
+                    bindesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize);
+                    uvdbg("Bulk IN EP addr:%d mxpacketsize:%d\n",
+                          bindesc.addr, bindesc.mxpacketsize);
+                  }
+              }
+          }
+          break;
+
+        /* Other descriptors are just ignored for now */
+
+        default:
+          break;
+        }
+
+      /* Increment the address of the next descriptor */
+ 
+      configdesc += desc->len;
+      remaining  -= desc->len;
+    }
+
+  /* Sanity checking... did we find all of things that we need? Hmmm..  I wonder..
+   * can we work read-only or write-only if only one bulk endpoint found?
+   */
+    
+  if (found != USBHOST_ALLFOUND)
+    {
+      ulldbg("ERROR: Found IF:%s BIN:%s BOUT:%s\n",
+             (found & USBHOST_IFFOUND) != 0  ? "YES" : "NO",
+             (found & USBHOST_BINFOUND) != 0 ? "YES" : "NO",
+             (found & USBHOST_BOUTFOUND) != 0 ? "YES" : "NO");
+      return -EINVAL;
+    }
+
+  /* We are good... Allocate the endpoints */
+
+  ret = DRVR_EPALLOC(priv->drvr, &boutdesc, &priv->epout);
+  if (ret != OK)
+    {
+      udbg("ERROR: Failed to allocate Bulk OUT endpoint\n");
+      return ret;
+    }
+
+  ret = DRVR_EPALLOC(priv->drvr, &bindesc, &priv->epin);
+  if (ret != OK)
+    {
+      udbg("ERROR: Failed to allocate Bulk IN endpoint\n");
+      (void)DRVR_EPFREE(priv->drvr, priv->epout);
+      return ret;
+    }
+
+  ullvdbg("Endpoints allocated\n");
+  return OK;
+}
+
+/****************************************************************************
+ * Name: usbhost_devinit
+ *
+ * Description:
+ *   The USB device has been successfully connected.  This completes the
+ *   initialization operations.  It is first called after the
+ *   configuration descriptor has been received.
+ *
+ *   This function is called from the connect() method.  This function always
+ *   executes on the thread of the caller of connect().
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline int usbhost_devinit(FAR struct usbhost_state_s *priv)
+{
+  int ret;
+
+  /* Set aside a transfer buffer for exclusive use by the class driver */
+
+  /* Increment the reference count.  This will prevent usbhost_destroy() from
+   * being called asynchronously if the device is removed.
+   */
+
+  priv->crefs++;
+  DEBUGASSERT(priv->crefs == 2);
+
+  /* Configure the device */
+
+  /* Register the driver */
+
+  if (ret == OK)
+    {
+      char devname[DEV_NAMELEN];
+
+      uvdbg("Register block driver\n");
+      usbhost_mkdevname(priv, devname);
+      // ret = register_blockdriver(devname, &g_bops, 0, priv);
+    }
+
+  /* Check if we successfully initialized. We now have to be concerned
+   * about asynchronous modification of crefs because the block
+   * driver has been registerd.
+   */
+
+  if (ret == OK)
+    {
+      usbhost_takesem(&priv->exclsem);
+      DEBUGASSERT(priv->crefs >= 2);
+
+      /* Handle a corner case where (1) open() has been called so the
+       * reference count is > 2, but the device has been disconnected.
+       * In this case, the class instance needs to persist until close()
+       * is called.
+       */
+
+      if (priv->crefs <= 2 && priv->disconnected)
+        {
+          /* We don't have to give the semaphore because it will be
+           * destroyed when usb_destroy is called.
+           */
+  
+          ret = -ENODEV;
+        }
+      else
+        {
+          /* Ready for normal operation as a block device driver */
+
+          uvdbg("Successfully initialized\n");
+          priv->crefs--;
+          usbhost_givesem(&priv->exclsem);
+        }
+    }
+
+  /* Disconnect on any errors detected during volume initialization */
+
+  if (ret != OK)
+    {
+      udbg("ERROR! Aborting: %d\n", ret);
+      usbhost_destroy(priv);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: usbhost_getle16
+ *
+ * Description:
+ *   Get a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   val - A pointer to the first byte of the little endian value.
+ *
+ * Returned Values:
+ *   A uint16_t representing the whole 16-bit integer value
+ *
+ ****************************************************************************/
+
+static inline uint16_t usbhost_getle16(const uint8_t *val)
+{
+  return (uint16_t)val[1] << 8 | (uint16_t)val[0];
+}
+
+/****************************************************************************
+ * Name: usbhost_putle16
+ *
+ * Description:
+ *   Put a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 16-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_putle16(uint8_t *dest, uint16_t val)
+{
+  dest[0] = val & 0xff; /* Little endian means LS byte first in byte stream */
+  dest[1] = val >> 8;
+}
+
+/****************************************************************************
+ * Name: usbhost_getle32
+ *
+ * Description:
+ *   Get a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the big endian value.
+ *   val - The 32-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static inline uint32_t usbhost_getle32(const uint8_t *val)
+{
+ /* Little endian means LS halfword first in byte stream */
+
+  return (uint32_t)usbhost_getle16(&val[2]) << 16 | (uint32_t)usbhost_getle16(val);
+}
+
+/****************************************************************************
+ * Name: usbhost_putle32
+ *
+ * Description:
+ *   Put a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 32-bit value to be saved.
+ *
+ * Returned Values:
+ *   None
+ *
+ ****************************************************************************/
+
+static void usbhost_putle32(uint8_t *dest, uint32_t val)
+{
+  /* Little endian means LS halfword first in byte stream */
+
+  usbhost_putle16(dest, (uint16_t)(val & 0xffff));
+  usbhost_putle16(dest+2, (uint16_t)(val >> 16));
+}
+
+/****************************************************************************
+ * Name: usbhost_tdalloc
+ *
+ * Description:
+ *   Allocate transfer descriptor memory.
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   On sucess, zero (OK) is returned.  On failure, an negated errno value
+ *   is returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_tdalloc(FAR struct usbhost_state_s *priv)
+{
+  DEBUGASSERT(priv && priv->tdbuffer == NULL);
+  return DRVR_ALLOC(priv->drvr, &priv->tdbuffer, &priv->tdbuflen);
+}
+
+/****************************************************************************
+ * Name: usbhost_tdfree
+ *
+ * Description:
+ *   Free transfer descriptor memory.
+ *
+ * Input Parameters:
+ *   priv - A reference to the class instance.
+ *
+ * Returned Values:
+ *   On sucess, zero (OK) is returned.  On failure, an negated errno value
+ *   is returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+static inline int usbhost_tdfree(FAR struct usbhost_state_s *priv)
+{
+  int result = OK;
+  DEBUGASSERT(priv);
+
+  if (priv->tdbuffer)
+    {
+      DEBUGASSERT(priv->drvr);
+      result         = DRVR_FREE(priv->drvr, priv->tdbuffer);
+      priv->tdbuffer = NULL;
+      priv->tdbuflen = 0;
+    }
+  return result;
+}
+
+/****************************************************************************
+ * struct usbhost_registry_s methods
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_create
+ *
+ * Description:
+ *   This function implements the create() method of struct usbhost_registry_s. 
+ *   The create() method is a callback into the class implementation.  It is
+ *   used to (1) create a new instance of the USB host class state and to (2)
+ *   bind a USB host driver "session" to the class instance.  Use of this
+ *   create() method will support environments where there may be multiple
+ *   USB ports and multiple USB devices simultaneously connected.
+ *
+ * Input Parameters:
+ *   drvr - An instance of struct usbhost_driver_s that the class
+ *     implementation will "bind" to its state structure and will
+ *     subsequently use to communicate with the USB host driver.
+ *   id - In the case where the device supports multiple base classes,
+ *     subclasses, or protocols, this specifies which to configure for.
+ *
+ * Returned Values:
+ *   On success, this function will return a non-NULL instance of struct
+ *   usbhost_class_s that can be used by the USB host driver to communicate
+ *   with the USB host class.  NULL is returned on failure; this function
+ *   will fail only if the drvr input parameter is NULL or if there are
+ *   insufficient resources to create another USB host class instance.
+ *
+ ****************************************************************************/
+
+static FAR struct usbhost_class_s *usbhost_create(FAR struct usbhost_driver_s *drvr,
+                                                  FAR const struct usbhost_id_s *id)
+{
+  FAR struct usbhost_state_s *priv;
+
+  /* Allocate a USB host class instance */
+
+  priv = usbhost_allocclass();
+  if (priv)
+    {
+      /* Initialize the allocated storage class instance */
+
+      memset(priv, 0, sizeof(struct usbhost_state_s));
+
+      /* Assign a device number to this class instance */
+
+      if (usbhost_allocdevno(priv) == OK)
+        {
+         /* Initialize class method function pointers */
+
+          priv->class.connect      = usbhost_connect;
+          priv->class.disconnected = usbhost_disconnected;
+
+          /* The initial reference count is 1... One reference is held by the driver */
+
+          priv->crefs              = 1;
+
+          /* Initialize semphores (this works okay in the interrupt context) */
+
+          sem_init(&priv->exclsem, 0, 1);
+
+          /* Bind the driver to the storage class instance */
+
+          priv->drvr               = drvr;
+
+          /* NOTE: We do not yet know the geometry of the USB mass storage device */
+ 
+          /* Return the instance of the USB mass storage class */
+ 
+          return &priv->class;
+        }
+    }
+
+  /* An error occurred. Free the allocation and return NULL on all failures */
+
+  if (priv)
+    {
+      usbhost_freeclass(priv);
+    }
+  return NULL;
+}
+
+/****************************************************************************
+ * struct usbhost_class_s methods
+ ****************************************************************************/
+/****************************************************************************
+ * Name: usbhost_connect
+ *
+ * Description:
+ *   This function implements the connect() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to provide the device's configuration
+ *   descriptor to the class so that the class may initialize properly
+ *
+ * Input Parameters:
+ *   class - The USB host class entry previously obtained from a call to create().
+ *   configdesc - A pointer to a uint8_t buffer container the configuration descripor.
+ *   desclen - The length in bytes of the configuration descriptor.
+ *   funcaddr - The USB address of the function containing the endpoint that EP0
+ *     controls
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value is
+ *   returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function will *not* be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static int usbhost_connect(FAR struct usbhost_class_s *class,
+                           FAR const uint8_t *configdesc, int desclen,
+                           uint8_t funcaddr)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)class;
+  int ret;
+
+  DEBUGASSERT(priv != NULL && 
+              configdesc != NULL &&
+              desclen >= sizeof(struct usb_cfgdesc_s));
+
+  /* Parse the configuration descriptor to get the endpoints */
+
+  ret = usbhost_cfgdesc(priv, configdesc, desclen, funcaddr);
+  if (ret != OK)
+    {
+      udbg("usbhost_cfgdesc() failed: %d\n", ret);
+    }
+  else
+    {
+      /* Now configure the device and register the NuttX driver */
+
+      ret = usbhost_devinit(priv);
+      if (ret != OK)
+        {
+          udbg("usbhost_devinit() failed: %d\n", ret);
+        }
+    }
+ 
+  return ret;
+}
+
+/****************************************************************************
+ * Name: usbhost_disconnected
+ *
+ * Description:
+ *   This function implements the disconnected() method of struct
+ *   usbhost_class_s.  This method is a callback into the class
+ *   implementation.  It is used to inform the class that the USB device has
+ *   been disconnected.
+ *
+ * Input Parameters:
+ *   class - The USB host class entry previously obtained from a call to
+ *     create().
+ *
+ * Returned Values:
+ *   On success, zero (OK) is returned. On a failure, a negated errno value
+ *   is returned indicating the nature of the failure
+ *
+ * Assumptions:
+ *   This function may be called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+static int usbhost_disconnected(struct usbhost_class_s *class)
+{
+  FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)class;
+  irqstate_t flags;
+
+  DEBUGASSERT(priv != NULL);
+
+  /* Set an indication to any users of the mass storage device that the device
+   * is no longer available.
+   */
+
+  flags              = irqsave();
+  priv->disconnected = true;
+
+  /* Now check the number of references on the class instance.  If it is one,
+   * then we can free the class instance now.  Otherwise, we will have to
+   * wait until the holders of the references free them by closing the
+   * block driver.
+   */
+
+  ullvdbg("crefs: %d\n", priv->crefs);
+  if (priv->crefs == 1)
+    {
+      /* Destroy the class instance.  If we are executing from an interrupt
+       * handler, then defer the destruction to the worker thread.
+       * Otherwise, destroy the instance now.
+       */
+
+      if (up_interrupt_context())
+        {
+          /* Destroy the instance on the worker thread. */
+
+          uvdbg("Queuing destruction: worker %p->%p\n", priv->work.worker, usbhost_destroy);
+          DEBUGASSERT(priv->work.worker == NULL);
+          (void)work_queue(&priv->work, usbhost_destroy, priv, 0);
+       }
+      else
+        {
+          /* Do the work now */
+
+          usbhost_destroy(priv);
+        }
+    }
+
+  irqrestore(flags);  
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_skelinit
+ *
+ * Description:
+ *   Initialize the USB storage class.  This function should be called
+ *   be platform-specific code in order to initialize and register support
+ *   for the USB host storage class.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Values:
+ *   On success this function will return zero (OK);  A negated errno value
+ *   will be returned on failure.
+ *
+ ****************************************************************************/
+
+int usbhost_skelinit(void)
+{
+  /* Perform any one-time initialization of the class implementation */
+
+  /* Advertise our availability to support (certain) devices */
+
+  return usbhost_registerclass(&g_skeleton);
+}
+
diff --git a/include/nuttx/usb/hid.h b/include/nuttx/usb/hid.h
new file mode 100755
index 00000000000..9fcf2b3ee7a
--- /dev/null
+++ b/include/nuttx/usb/hid.h
@@ -0,0 +1,190 @@
+/****************************************************************************
+ * include/nuttx/usb/hid.h
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * References:
+ *   Universal Serial Bus (USB), Device Class Definition for Human Interface
+ *   Devices (HID), Firmware Specification—6/27/01, Version 1.11.
+ *
+ * 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.
+ * 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. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_USB_HID_H
+#define __INCLUDE_NUTTX_USB_HID_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Preprocessor definitions
+ ****************************************************************************/
+
+/* Subclass and Protocol ****************************************************/
+/* Subclass codes (4.2) */
+
+#define USBHID_SUBCLASS_NONE       0 /* No subclass */
+#define USBHID_SUBCLASS_BOOTIF     1 /* Boot Interface Subclass */
+
+/* A variety of protocols are supported HID devices. The protocol member of
+ * an Interface descriptor only has meaning if the subclass member declares
+ * that the device supports a boot interface, otherwise it is 0. (4.3)
+ */
+
+#define USBHID_PROTOCOL_NONE       0
+#define USBHID_PROTOCOL_KEYBOARD   1
+#define USBHID_PROTOCOL_MOUSE      2
+
+/* HID Descriptor ***********************************************************/
+
+#define USBHID_COUNTRY_NONE        0x00 /* Not Supported */
+#define USBHID_COUNTRY_ARABIC      0x01 /* Arabic */
+#define USBHID_COUNTRY_BELGIAN     0x02 /* Belgian */
+#define USBHID_COUNTRY_CANADA      0x03 /* Canadian-Bilingual */
+#define USBHID_COUNTRY_CANADRFR    0x04 /* Canadian-French */
+#define USBHID_COUNTRY_CZECH       0x05 /* Czech Republic */
+#define USBHID_COUNTRY_DANISH      0x06 /* Danish */
+#define USBHID_COUNTRY_FINNISH     0x07 /* Finnish */
+#define USBHID_COUNTRY_FRENCH      0x08 /* French */
+#define USBHID_COUNTRY_GERMAN      0x09 /* German */
+#define USBHID_COUNTRY_GREEK       0x10 /* Greek */
+#define USBHID_COUNTRY_HEBREW      0x11 /* Hebrew */
+#define USBHID_COUNTRY_HUNGARY     0x12 /* Hungary */
+#define USBHID_COUNTRY_ISO         0x13 /* International (ISO) */
+#define USBHID_COUNTRY_ITALIAN     0x14 /* Italian */
+#define USBHID_COUNTRY_JAPAN       0x15 /* Japan (Katakana) */
+#define USBHID_COUNTRY_KOREAN      0x16 /* Korean  */
+#define USBHID_COUNTRY_LATINAM     0x17 /* Latin American */
+#define USBHID_COUNTRY_DUTCH       0x18 /* Netherlands/Dutch */
+#define USBHID_COUNTRY_NORWEGIAN   0x19 /* Norwegian */
+#define USBHID_COUNTRY_PERSIAN     0x20 /* Persian (Farsi) */
+#define USBHID_COUNTRY_POLAND      0x21 /* Poland */
+#define USBHID_COUNTRY_PORTUGUESE  0x22 /* Portuguese */
+#define USBHID_COUNTRY_RUSSIA      0x23 /* Russia */
+#define USBHID_COUNTRY_SLOVAKIA    0x24 /* Slovakia */
+#define USBHID_COUNTRY_SPANISH     0x25 /* Spanish */
+#define USBHID_COUNTRY_SWEDISH     0x26 /* Swedish */
+#define USBHID_COUNTRY_SWISSFR     0x27 /* Swiss/French */
+#define USBHID_COUNTRY_SWISSGR     0x28 /* Swiss/German */
+#define USBHID_COUNTRY_SWITZERLAND 0x29 /* Switzerland */
+#define USBHID_COUNTRY_TAIWAN      0x30 /* Taiwan */
+#define USBHID_COUNTRY_TURKISHQ    0x31 /* Turkish-Q */
+#define USBHID_COUNTRY_UK          0x32 /* UK */
+#define USBHID_COUNTRY_US          0x33 /* US */
+#define USBHID_COUNTRY_YUGOSLAVIA  0x34 /* Yugoslavia */
+#define USBHID_COUNTRY_TURKISHF    0x35 /* Turkish-F */
+
+/* Main Items (6.2.2.4) */
+
+#define USBHID_MAIN_SIZE(pfx)             ((pfx) & 3)
+#define USBHID_MAIN_INPUT_PREFIX          0x80
+#define USBHID_MAIN_INPUT_CONSTANT        (1 << 0) /* Constant(1) vs Data(0) */
+#define USBHID_MAIN_INPUT_VARIABLE        (1 << 1) /* Variable(1) vs Array(0) */
+#define USBHID_MAIN_INPUT_RELATIVE        (1 << 2) /* Relative(1) vs Absolute(0) */
+#define USBHID_MAIN_INPUT_WRAP            (1 << 3) /* Wrap(1) vs No Wrap(0) */
+#define USBHID_MAIN_INPUT_NONLINEAR       (1 << 4) /* Non Linear(1) vs Linear(0) */
+#define USBHID_MAIN_INPUT_NOPREFERRED     (1 << 5) /* No Preferred (1) vs Preferred State(0) */
+#define USBHID_MAIN_INPUT_NULLSTATE       (1 << 6) /* Null state(1) vs No Null position(0) */
+#define USBHID_MAIN_INPUT_BUFFEREDBYTES   (1 << 8) /* Buffered Bytes(1) vs Bit Field(0) */
+
+#define USBHID_MAIN_OUTPUT_PREFIX         0x90
+#define USBHID_MAIN_OUTPUT_CONSTANT       (1 << 0) /* Constant(1) vs Data(0) */
+#define USBHID_MAIN_OUTPUT_VARIABLE       (1 << 1) /* Variable(1) vs Array(0) */
+#define USBHID_MAIN_OUTPUT_RELATIVE       (1 << 2) /* Relative(1) vs Absolute(0) */
+#define USBHID_MAIN_OUTPUT_WRAP           (1 << 3) /* Wrap(1) vs No Wrap(0) */
+#define USBHID_MAIN_OUTPUT_NONLINEAR      (1 << 4) /* Non Linear(1) vs Linear(0) */
+#define USBHID_MAIN_OUTPUT_NOPREFERRED    (1 << 5) /* No Preferred (1) vs Preferred State(0) */
+#define USBHID_MAIN_OUTPUT_NULLSTATE      (1 << 6) /* Null state(1) vs No Null position(0) */
+#define USBHID_MAIN_OUTPUT_VOLATILE       (1 << 7) /* Volatile(1) vs Non volatile(0) */
+#define USBHID_MAIN_OUTPUT_BUFFEREDBYTES  (1 << 8) /* Buffered Bytes(1) vs Bit Field(0) */
+
+#define USBHID_MAIN_FEATURE_PREFIX        0xb0
+#define USBHID_MAIN_FEATURE_CONSTANT      (1 << 0) /* Constant(1) vs Data(0) */
+#define USBHID_MAIN_FEATURE_VARIABLE      (1 << 1) /* Variable(1) vs Array(0) */
+#define USBHID_MAIN_FEATURE_RELATIVE      (1 << 2) /* Relative(1) vs Absolute(0) */
+#define USBHID_MAIN_FEATURE_WRAP          (1 << 3) /* Wrap(1) vs No Wrap(0) */
+#define USBHID_MAIN_FEATURE_NONLINEAR     (1 << 4) /* Non Linear(1) vs Linear(0) */
+#define USBHID_MAIN_FEATURE_NOPREFERRED   (1 << 5) /* No Preferred (1) vs Preferred State(0) */
+#define USBHID_MAIN_FEATURE_NULLSTATE     (1 << 6) /* Null state(1) vs No Null position(0) */
+#define USBHID_MAIN_FEATURE_VOLATILE      (1 << 7) /* Volatile(1) vs Non volatile(0) */
+#define USBHID_MAIN_FEATURE_BUFFEREDBYTES (1 << 8) /* Buffered Bytes(1) vs Bit Field(0) */
+
+#define USBHID_MAIN_COLLECTION_PREFIX     0xa0
+#define USBHID_MAIN_COLLECTION_PHYSICAL   0x00 /* Physical (group of axes) */
+#define USBHID_MAIN_COLLECTION_APPL       0x01 /* Application (mouse, keyboard) */
+#define USBHID_MAIN_COLLECTION_LOGICAL    0x02 /* Logical (interrelated data) */
+#define USBHID_MAIN_COLLECTION_REPORT     0x03 /* Report */
+#define USBHID_MAIN_COLLECTION_ARRAY      0x04 /* Named Array */
+#define USBHID_MAIN_COLLECTION_SWITCH     0x05 /* Usage Switch */
+#define USBHID_MAIN_COLLECTION_MODIFIER   0x06 /* Usage Modifier */
+
+#define USBHID_MAIN_ENDCOLLECTION_PREFIX  0xc0
+
+/* Global Items (6.2.2.7) */
+
+#define USBHID_GLOBAL_SIZE(pfx)           ((pfx) & 3)
+#define USBHID_GLOBAL_USAGEPAGE_PREFIX    0x04 /* Usage Page */
+#define USBHID_GLOBAL_LOGMINIMUM_PREFIX   0x14 /* Logical Minimum */
+#define USBHID_GLOBAL_LOGMAXIMUM_PREFIX   0x24 /* Logical Maximum */
+#define USBHID_GLOBAL_PHYSMINIMUM_PREFIX  0x34 /* Physical Minimum */
+#define USBHID_GLOBAL_PHYSMAXIMUM_PREFIX  0x44 /* Physical Maximum */
+#define USBHID_GLOBAL_UNITEXP_PREFIX      0x54 /* Unit Exponent */
+#define USBHID_GLOBAL_UNIT_PREFIX         0x64 /* Unit */
+#define USBHID_GLOBAL_REPORTSIZE_PREFIX   0x74 /* Report Size */
+#define USBHID_GLOBAL_REPORTID_PREFIX     0x84 /*Report ID */
+#define USBHID_GLOBAL_REPORTCOUNT_PREFIX  0x94 /* Report Count */
+#define USBHID_GLOBAL_PUSH_PREFIX         0xa4 /* Push */
+#define USBHID_GLOBAL_Pop_PREFIX          0xb4 /* Pop */
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+# define EXTERN extern "C"
+extern "C" {
+#else
+# define EXTERN extern
+#endif
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_USB_HID_H */