diff options
Diffstat (limited to 'nuttx/drivers/usbhost/usbhost_findclass.c')
| -rw-r--r-- | nuttx/drivers/usbhost/usbhost_findclass.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/nuttx/drivers/usbhost/usbhost_findclass.c b/nuttx/drivers/usbhost/usbhost_findclass.c new file mode 100644 index 000000000..f08aff580 --- /dev/null +++ b/nuttx/drivers/usbhost/usbhost_findclass.c @@ -0,0 +1,199 @@ +/**************************************************************************** + * drivers/usbhost/usbhost_findclass.c + * + * Copyright (C) 2010 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 <sys/types.h> +#include <stdbool.h> +#include <debug.h> + +#include <nuttx/usb/usb.h> +#include <nuttx/usb/usbhost.h> +#include <arch/irq.h> + +#include "usbhost_registry.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * 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 Values: + * TRUE - the class will support this device. + * + ****************************************************************************/ + +static bool usbhost_idmatch(const struct usbhost_id_s *classid, + const struct usbhost_id_s *devid) +{ + uvdbg("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 Values: + * 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 *class; + irqstate_t flags; + int ndx; + + DEBUGASSERT(id); + uvdbg("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-linkedlist 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 = irqsave(); + + /* Examine each register class in the linked list */ + + for (class = g_classregistry; class; class = class->flink) + { + /* If the registered class supports more than one ID, subclass, or + * protocol, then try each. + */ + + uvdbg("Checking class:%p nids:%d\n", class, class->nids); + for (ndx = 0; ndx < class->nids; ndx++) + { + /* Did we find a matching ID? */ + + if (usbhost_idmatch(&class->id[ndx], id)) + { + /* Yes.. restore interrupts and return the class info */ + + irqrestore(flags); + return class; + } + } + } + + /* Not found... restore interrupts and return NULL */ + + irqrestore(flags); + return NULL; +} + |