123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169 |
- /****************************************************************************
- * drivers/usbhost/usbhost_findclass.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 <sys/types.h>
- #include <stdbool.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/irq.h>
- #include <nuttx/usb/usb.h>
- #include <nuttx/usb/usbhost.h>
- #include "usbhost_registry.h"
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: usbhost_idmatch
- *
- * Description:
- * Check if the class ID matches what the host controller found.
- *
- * Input Parameters:
- * classid - ID info for the class under consideration.
- * devid - ID info reported by the device.
- *
- * Returned Value:
- * TRUE - the class will support this device.
- *
- ****************************************************************************/
- static bool usbhost_idmatch(const struct usbhost_id_s *classid,
- const struct usbhost_id_s *devid)
- {
- uinfo("Compare to class:%d subclass:%d protocol:%d vid:%04x pid:%04x\n",
- classid->base, classid->subclass, classid->proto,
- classid->vid, classid->pid);
- /* The base class ID, subclass and protocol have to match up in any event */
- if (devid->base == classid->base &&
- devid->subclass == classid->subclass &&
- devid->proto == classid->proto)
- {
- /* If this is a vendor-specific class ID, then the VID and PID have to
- * match as well.
- */
- if (devid->base == USB_CLASS_VENDOR_SPEC)
- {
- /* Vendor specific... do the VID and PID also match? */
- if (devid->vid == classid->vid && devid->pid == classid->pid)
- {
- /* Yes.. then we have a match */
- return true;
- }
- }
- else
- {
- /* Not vendor specific? Then we have a match */
- return true;
- }
- }
- /* No match.. not supported */
- return false;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: usbhost_findclass
- *
- * Description:
- * Find a USB host class implementation previously registered by
- * usbhost_registerclass(). On success, an instance of struct
- * usbhost_registry_s will be returned. That instance will contain all of
- * the information that will be needed to obtain and bind a struct
- * usbhost_class_s instance for the device.
- *
- * Input Parameters:
- * id - Identifies the USB device class that has connect to the USB host.
- *
- * Returned Value:
- * On success this function will return a non-NULL instance of struct
- * usbhost_registry_s. NULL will be returned on failure. This function
- * can only fail if (1) id is NULL, or (2) no USB host class is registered
- * that matches the device class ID.
- *
- ****************************************************************************/
- const struct usbhost_registry_s *usbhost_findclass(
- const struct usbhost_id_s *id)
- {
- struct usbhost_registry_s *usbclass;
- irqstate_t flags;
- int ndx;
- DEBUGASSERT(id);
- uinfo("Looking for class:%d subclass:%d protocol:%d vid:%04x pid:%04x\n",
- id->base, id->subclass, id->proto, id->vid, id->pid);
- /* g_classregistry is a singly-linked list of class ID information added by
- * calls to usbhost_registerclass(). Since this list is accessed from USB
- * host controller interrupt handling logic, accesses to this list must be
- * protected by disabling interrupts.
- */
- flags = enter_critical_section();
- /* Examine each register class in the linked list */
- for (usbclass = g_classregistry; usbclass; usbclass = usbclass->flink)
- {
- /* If the registered class supports more than one ID, subclass, or
- * protocol, then try each.
- */
- uinfo("Checking class:%p nids:%d\n", usbclass, usbclass->nids);
- for (ndx = 0; ndx < usbclass->nids; ndx++)
- {
- /* Did we find a matching ID? */
- if (usbhost_idmatch(&usbclass->id[ndx], id))
- {
- /* Yes.. restore interrupts and return the class info */
- leave_critical_section(flags);
- return usbclass;
- }
- }
- }
- /* Not found... restore interrupts and return NULL */
- leave_critical_section(flags);
- return NULL;
- }
|