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incubator-nuttx/drivers/usbhost/usbhost_skeleton.c

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/****************************************************************************
* drivers/usbhost/usbhost_skeleton.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/arch.h>
#include <nuttx/semaphore.h>
#include <nuttx/wqueue.h>
#include <nuttx/usb/usb.h>
#include <nuttx/usb/usbhost.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_SCHED_WORKQUEUE
# warning "Worker thread support is required (CONFIG_SCHED_WORKQUEUE)"
#endif
/* Driver support ***********************************************************/
/* This format is used to construct the /dev/skel[n] device driver path. It
* defined here so that it will be used consistently in all places.
*/
#define DEV_FORMAT "/dev/skel%c"
#define DEV_NAMELEN 12
/* Used in usbhost_cfgdesc() */
#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 class
* driver.
*/
struct usbhost_state_s
{
/* This is the externally visible portion of the state */
struct usbhost_class_s usbclass;
/* The remainder of the fields are provide to the class driver */
char devchar; /* Character identifying the /dev/skel[n] device */
volatile bool disconnected; /* TRUE: Device has been disconnected */
uint8_t ifno; /* Interface number */
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 *tbuffer; /* The allocated transfer buffer */
size_t tbuflen; /* Size of the allocated transfer buffer */
usbhost_ep_t epin; /* IN endpoint */
usbhost_ep_t epout; /* OUT endpoint */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Semaphores */
static int usbhost_takesem(FAR sem_t *sem);
static void usbhost_forcetake(FAR sem_t *sem);
#define usbhost_givesem(s) nxsem_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 *usbclass);
/* 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,
FAR char *devname);
/* Worker thread actions */
static void usbhost_destroy(FAR void *arg);
/* Helpers for usbhost_connect() */
static inline int usbhost_cfgdesc(FAR struct usbhost_state_s *priv,
FAR const uint8_t *configdesc,
int desclen);
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_talloc(FAR struct usbhost_state_s *priv);
static inline int usbhost_tfree(FAR struct usbhost_state_s *priv);
/* struct usbhost_registry_s methods */
static struct usbhost_class_s *
usbhost_create(FAR struct usbhost_hubport_s *hport,
FAR const struct usbhost_id_s *id);
/* struct usbhost_class_s methods */
static int usbhost_connect(FAR struct usbhost_class_s *usbclass,
FAR const uint8_t *configdesc, int desclen);
static int usbhost_disconnected(FAR struct usbhost_class_s *usbclass);
/* Driver methods -- depend upon the type of NuttX driver interface exported */
/****************************************************************************
* Private Data
****************************************************************************/
/* This structure provides the registry entry ID information that will be
* used to associate the USB class driver to a connected USB device.
*/
static 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/skela-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 int usbhost_takesem(FAR sem_t *sem)
{
return nxsem_wait_uninterruptible(sem);
}
/****************************************************************************
* Name: usbhost_forcetake
*
* Description:
* This is just another wrapper but this one continues even if the thread
* is canceled. This must be done in certain conditions where were must
* continue in order to clean-up resources.
*
****************************************************************************/
static void usbhost_forcetake(FAR sem_t *sem)
{
int ret;
do
{
ret = nxsem_wait_uninterruptible(sem);
/* The only expected error would -ECANCELED meaning that the
* parent thread has been canceled. We have to continue and
* terminate the poll in this case.
*/
DEBUGASSERT(ret == OK || ret == -ECANCELED);
}
while (ret < 0);
}
/****************************************************************************
* 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 Value:
* 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 *)
kmm_malloc(sizeof(struct usbhost_state_s));
uinfo("Allocated: %p\n", priv);
return priv;
}
/****************************************************************************
* Name: usbhost_freeclass
*
* Description:
* Free a class instance previously allocated by usbhost_allocclass().
*
* Input Parameters:
* usbclass - A reference to the class instance to be freed.
*
* Returned Value:
* None
*
****************************************************************************/
static inline void usbhost_freeclass(FAR struct usbhost_state_s *usbclass)
{
DEBUGASSERT(usbclass != NULL);
/* Free the class instance (perhaps calling sched_kmm_free() in case we are
* executing from an interrupt handler.
*/
uinfo("Freeing: %p\n", usbclass);
kmm_free(usbclass);
}
/****************************************************************************
* 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 = enter_critical_section();
for (devno = 0; devno < 26; devno++)
{
uint32_t bitno = 1 << devno;
if ((g_devinuse & bitno) == 0)
{
g_devinuse |= bitno;
priv->devchar = 'a' + devno;
leave_critical_section(flags);
return OK;
}
}
leave_critical_section(flags);
return -EMFILE;
}
static void usbhost_freedevno(FAR struct usbhost_state_s *priv)
{
int devno = 'a' - priv->devchar;
if (devno >= 0 && devno < 26)
{
irqstate_t flags = enter_critical_section();
g_devinuse &= ~(1 << devno);
leave_critical_section(flags);
}
}
static inline void usbhost_mkdevname(FAR struct usbhost_state_s *priv,
FAR char *devname)
{
snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->devchar);
}
/****************************************************************************
* Name: usbhost_destroy
*
* Description:
* The USB device has been disconnected and the reference 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 Value:
* None
*
****************************************************************************/
static void usbhost_destroy(FAR void *arg)
{
FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)arg;
FAR struct usbhost_hubport_s *hport;
FAR struct usbhost_driver_s *drvr;
DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL);
hport = priv->usbclass.hport;
DEBUGASSERT(hport->drvr);
drvr = hport->drvr;
uinfo("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 */
/* Free the function address assigned to this device */
usbhost_devaddr_destroy(hport, hport->funcaddr);
hport->funcaddr = 0;
/* Destroy the semaphores */
/* Disconnect the USB host device */
DRVR_DISCONNECT(drvr, hport);
/* 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
* descriptor.
* desclen - The length in bytes of the configuration descriptor.
*
* Returned Value:
* 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)
{
FAR struct usbhost_hubport_s *hport;
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 && priv->usbclass.hport &&
configdesc != NULL && desclen >= sizeof(struct usb_cfgdesc_s));
hport = priv->usbclass.hport;
/* 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:
{
FAR struct usb_ifdesc_s *ifdesc =
(FAR struct usb_ifdesc_s *)configdesc;
uinfo("Interface descriptor\n");
DEBUGASSERT(remaining >= USB_SIZEOF_IFDESC);
/* Save the interface number and mark ONLY the interface found */
priv->ifno = ifdesc->ifno;
found = USBHOST_IFFOUND;
}
break;
/* Endpoint descriptor. Here, 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;
uinfo("Endpoint descriptor\n");
DEBUGASSERT(remaining >= USB_SIZEOF_EPDESC);
/* Check for a bulk endpoint. */
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 endpoint. We don't know
* what to do with this.
*/
return -EINVAL;
}
found |= USBHOST_BOUTFOUND;
/* Save the bulk OUT endpoint information */
boutdesc.hport = hport;
boutdesc.addr = epdesc->addr &
USB_EP_ADDR_NUMBER_MASK;
boutdesc.in = false;
boutdesc.xfrtype = USB_EP_ATTR_XFER_BULK;
boutdesc.interval = epdesc->interval;
boutdesc.mxpacketsize =
usbhost_getle16(epdesc->mxpacketsize);
uinfo("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 endpoint. We don't know
* what to do with this.
*/
return -EINVAL;
}
found |= USBHOST_BINFOUND;
/* Save the bulk IN endpoint information */
bindesc.hport = hport;
bindesc.addr = epdesc->addr &
USB_EP_ADDR_NUMBER_MASK;
bindesc.in = 1;
bindesc.xfrtype = USB_EP_ATTR_XFER_BULK;
bindesc.interval = epdesc->interval;
bindesc.mxpacketsize =
usbhost_getle16(epdesc->mxpacketsize);
uinfo("Bulk IN EP addr:%d mxpacketsize:%d\n",
bindesc.addr, bindesc.mxpacketsize);
}
}
}
break;
/* Other descriptors are just ignored for now */
default:
break;
}
/* If we found everything we need with this interface, then break out
* of the loop early.
*/
if (found == USBHOST_ALLFOUND)
{
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? */
if (found != USBHOST_ALLFOUND)
{
uerr("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(hport->drvr, &boutdesc, &priv->epout);
if (ret < 0)
{
uerr("ERROR: Failed to allocate Bulk OUT endpoint\n");
return ret;
}
ret = DRVR_EPALLOC(hport->drvr, &bindesc, &priv->epin);
if (ret < 0)
{
uerr("ERROR: Failed to allocate Bulk IN endpoint\n");
DRVR_EPFREE(hport->drvr, priv->epout);
return ret;
}
uinfo("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 Value:
* None
*
****************************************************************************/
static inline int usbhost_devinit(FAR struct usbhost_state_s *priv)
{
int ret = OK;
/* 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 >= 0)
{
char devname[DEV_NAMELEN];
uinfo("Register block driver\n");
usbhost_mkdevname(priv, devname);
#if 0 /* Finish me */
ret = register_blockdriver(devname, &g_bops, 0, priv);
#endif
}
/* Check if we successfully initialized. We now have to be concerned
* about asynchronous modification of crefs because the block
* driver has been registered.
*/
if (ret >= 0)
{
ret = usbhost_takesem(&priv->exclsem);
if (ret < 0)
{
return ert;
}
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 */
uinfo("Successfully initialized\n");
priv->crefs--;
usbhost_givesem(&priv->exclsem);
}
}
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 Value:
* 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 Value:
* 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 Value:
* 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 Value:
* 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_talloc
*
* Description:
* Allocate transfer buffer memory.
*
* Input Parameters:
* priv - A reference to the class instance.
*
* Returned Value:
* On success, zero (OK) is returned. On failure, an negated errno value
* is returned to indicate the nature of the failure.
*
****************************************************************************/
static inline int usbhost_talloc(FAR struct usbhost_state_s *priv)
{
FAR struct usbhost_hubport_s *hport;
DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL &&
priv->tbuffer == NULL);
hport = priv->usbclass.hport;
return DRVR_ALLOC(hport->drvr, &priv->tbuffer, &priv->tbuflen);
}
/****************************************************************************
* Name: usbhost_tfree
*
* Description:
* Free transfer buffer memory.
*
* Input Parameters:
* priv - A reference to the class instance.
*
* Returned Value:
* On success, zero (OK) is returned. On failure, an negated errno value
* is returned to indicate the nature of the failure.
*
****************************************************************************/
static inline int usbhost_tfree(FAR struct usbhost_state_s *priv)
{
FAR struct usbhost_hubport_s *hport;
int result = OK;
DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL);
if (priv->tbuffer)
{
hport = priv->usbclass.hport;
result = DRVR_FREE(hport->drvr, priv->tbuffer);
priv->tbuffer = NULL;
priv->tbuflen = 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:
* hport - The hub hat manages the new class instance.
* id - In the case where the device supports multiple base classes,
* subclasses, or protocols, this specifies which to configure for.
*
* Returned Value:
* 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 hport 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_hubport_s *hport,
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->usbclass.hport = hport;
priv->usbclass.connect = usbhost_connect;
priv->usbclass.disconnected = usbhost_disconnected;
/* The initial reference count is 1... One reference is held by the driver */
priv->crefs = 1;
/* Initialize semaphores (this works okay in the interrupt context) */
nxsem_init(&priv->exclsem, 0, 1);
/* Return the instance of the USB class driver */
return &priv->usbclass;
}
}
/* 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:
* usbclass - The USB host class entry previously obtained from a call to
* create().
* configdesc - A pointer to a uint8_t buffer container the configuration
* descriptor.
* desclen - The length in bytes of the configuration descriptor.
*
* Returned Value:
* On success, zero (OK) is returned. On a failure, a negated errno value
* is returned indicating the nature of the failure
*
* NOTE that the class instance remains valid upon return with a failure.
* It is the responsibility of the higher level enumeration logic to call
* CLASS_DISCONNECTED to free up the class driver resources.
*
* Assumptions:
* - This function will *not* be called from an interrupt handler.
* - If this function returns an error, the USB host controller driver
* must call to DISCONNECTED method to recover from the error
*
****************************************************************************/
static int usbhost_connect(FAR struct usbhost_class_s *usbclass,
FAR const uint8_t *configdesc, int desclen)
{
FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)usbclass;
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);
if (ret < 0)
{
uerr("ERROR: usbhost_cfgdesc() failed: %d\n", ret);
}
else
{
/* Now configure the device and register the NuttX driver */
ret = usbhost_devinit(priv);
if (ret < 0)
{
uerr("ERROR: 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:
* usbclass - The USB host class entry previously obtained from a call to
* create().
*
* Returned Value:
* 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 *usbclass)
{
FAR struct usbhost_state_s *priv = (FAR struct usbhost_state_s *)usbclass;
irqstate_t flags;
DEBUGASSERT(priv != NULL);
/* Set an indication to any users of the device that the device is no
* longer available.
*/
flags = enter_critical_section();
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.
*/
uinfo("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. */
uinfo("Queuing destruction: worker %p->%p\n",
priv->work.worker, usbhost_destroy);
DEBUGASSERT(priv->work.worker == NULL);
work_queue(HPWORK, &priv->work, usbhost_destroy, priv, 0);
}
else
{
/* Do the work now */
usbhost_destroy(priv);
}
}
leave_critical_section(flags);
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: usbhost_skelinit
*
* Description:
* Initialize the USB class driver. This function should be called
* be platform-specific code in order to initialize and register support
* for the USB host class device.
*
* Input Parameters:
* None
*
* Returned Value:
* 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);
}
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