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Diffstat (limited to 'usblib/host/usbhaudio.c')
| -rw-r--r-- | usblib/host/usbhaudio.c | 1528 |
1 files changed, 1528 insertions, 0 deletions
diff --git a/usblib/host/usbhaudio.c b/usblib/host/usbhaudio.c new file mode 100644 index 0000000..fcaa9c3 --- /dev/null +++ b/usblib/host/usbhaudio.c @@ -0,0 +1,1528 @@ +//*****************************************************************************
+//
+// usbhaudio.c - USB host audio driver.
+//
+// Copyright (c) 2010-2012 Texas Instruments Incorporated. All rights reserved.
+// Software License Agreement
+//
+// Texas Instruments (TI) is supplying this software for use solely and
+// exclusively on TI's microcontroller products. The software is owned by
+// TI and/or its suppliers, and is protected under applicable copyright
+// laws. You may not combine this software with "viral" open-source
+// software in order to form a larger program.
+//
+// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
+// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
+// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
+// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
+// DAMAGES, FOR ANY REASON WHATSOEVER.
+//
+// This is part of revision 9453 of the Stellaris USB Library.
+//
+//*****************************************************************************
+
+#include "inc/hw_types.h"
+#include "driverlib/usb.h"
+#include "usblib/usblib.h"
+#include "usblib/usbaudio.h"
+#include "usblib/host/usbhost.h"
+#include "usblib/host/usbhaudio.h"
+
+//*****************************************************************************
+//
+//! \addtogroup usblib_host_class
+//! @{
+//
+//*****************************************************************************
+
+//*****************************************************************************
+//
+// These defines are used with the USBHostAudioFormatSet()
+// USBHostAudioFormatGet() to parse out interface number and alternate
+// setting number for an interface.
+//
+//*****************************************************************************
+#define INTERFACE_NUM_M 0x000000FF
+#define INTERFACE_ALTSETTING_M 0x0000FF00
+#define INTERFACE_ALTSETTING_S 8
+
+//*****************************************************************************
+//
+// Used to indicate an invalid interface descriptor number.
+//
+//*****************************************************************************
+#define INVALID_INTERFACE 0xffffffff
+
+//*****************************************************************************
+//
+// Forward declarations for the driver open and close calls.
+//
+//*****************************************************************************
+static void *USBAudioOpen(tUSBHostDevice *pDevice);
+static void USBAudioClose(void *pvInstance);
+
+//*****************************************************************************
+//
+// This is the structure for an instance of a USB host audio driver.
+//
+//*****************************************************************************
+typedef struct
+{
+ //
+ // Save the device instance.
+ //
+ tUSBHostDevice *pDevice;
+
+ //
+ // Used to save the call back.
+ //
+ tUSBHostAudioCallback pfnCallback;
+
+ //
+ // This is the control interface.
+ //
+ unsigned char ucIControl;
+
+ //
+ // This is the output streaming interface.
+ //
+ unsigned char ucOutInterface;
+
+ //
+ // This is the currently selected active output interface used with
+ // ucOutInterface interface.
+ //
+ unsigned char ucOutAltSetting;
+
+ //
+ // This is the streaming interface.
+ //
+ unsigned char ucInInterface;
+
+ //
+ // This is the currently selected active input interface used with
+ // ucInInterface interface.
+ //
+ unsigned char ucInAltSetting;
+
+ //
+ // The Isochronous endpoint addresses.
+ //
+ unsigned char ucIsochInAddress;
+ unsigned char ucIsochOutAddress;
+
+ tACInputTerminal *pInTerminal;
+ tACOutputTerminal *pOutTerminal;
+
+ //
+ // Holds the identifier for the Feature Unit for controlling volume.
+ //
+ unsigned char ucVolumeID;
+
+ tACFeatureUnit *pFeatureUnit;
+
+ //
+ // Holds what types of controls are enabled on the device.
+ //
+ unsigned short pusControls[3];
+
+ //
+ // Isochronous IN pipe.
+ //
+ unsigned long ulIsochInPipe;
+ unsigned short usPipeSizeIn;
+ tUSBHostAudioCallback pfnInCallback;
+ void *pvInBuffer;
+
+ //
+ // Isochronous OUT pipe.
+ //
+ unsigned long ulIsochOutPipe;
+ unsigned short usPipeSizeOut;
+ tUSBHostAudioCallback pfnOutCallback;
+ void *pvOutBuffer;
+
+ //
+ // State flags for this audio instance.
+ //
+ unsigned long ulFlags;
+}
+tUSBHostAudioInstance;
+
+//*****************************************************************************
+//
+// The internal flags for an audio interface.
+//
+//*****************************************************************************
+#define AUDIO_FLAG_OUT_ACTIVE 1 // Audio output is active.
+#define AUDIO_FLAG_IN_ACTIVE 2 // Audio input is active.
+
+//*****************************************************************************
+//
+// The USB Host audio instance.
+//
+//*****************************************************************************
+static tUSBHostAudioInstance g_AudioDevice =
+{
+ 0
+};
+
+//*****************************************************************************
+//
+//! This constant global structure defines the Audio Class Driver that is
+//! provided with the USB library.
+//
+//*****************************************************************************
+const tUSBHostClassDriver g_USBHostAudioClassDriver =
+{
+ USB_CLASS_AUDIO,
+ USBAudioOpen,
+ USBAudioClose,
+ 0
+};
+
+//*****************************************************************************
+//
+// This is the internal function that handles callbacks from the USB IN pipe.
+//
+//*****************************************************************************
+static void
+PipeCallbackIN(unsigned long ulPipe, unsigned long ulEvent)
+{
+ //
+ // Only handle the data available callback and pass it on to the
+ // application.
+ //
+ if(ulEvent == USB_EVENT_RX_AVAILABLE)
+ {
+ if(g_AudioDevice.pfnInCallback)
+ {
+ g_AudioDevice.pfnInCallback(
+ g_AudioDevice.pvInBuffer, 0, USB_EVENT_RX_AVAILABLE);
+ }
+ }
+}
+
+//*****************************************************************************
+//
+// This is the internal function that handles callbacks from the USB OUT pipe.
+//
+//*****************************************************************************
+static void
+PipeCallbackOUT(unsigned long ulPipe, unsigned long ulEvent)
+{
+ //
+ // Only handle the transmit complete callback and pass it on to the
+ // application.
+ //
+ if(ulEvent == USB_EVENT_TX_COMPLETE)
+ {
+ if(g_AudioDevice.pfnOutCallback)
+ {
+ g_AudioDevice.pfnOutCallback(
+ g_AudioDevice.pvOutBuffer, 0, USB_EVENT_TX_COMPLETE);
+ }
+ }
+}
+
+//*****************************************************************************
+//
+// Finds a given terminal and type in an audio configuration descriptor.
+//
+//*****************************************************************************
+static tDescriptorHeader *
+AudioTerminalGet(tConfigDescriptor *pConfigDesc, unsigned long ulTerminal,
+ unsigned long ulTerminalType)
+{
+ tACOutputTerminal *pOutput;
+ tDescriptorHeader *pHeader;
+ long lBytesRemaining;
+
+ pHeader = (tDescriptorHeader *)pConfigDesc;
+ lBytesRemaining = pConfigDesc->wTotalLength;
+
+ while(lBytesRemaining > 0)
+ {
+ //
+ // Output and input terminals are the same past the bDescriptorSubtype
+ // and wTerminalType that are being searched for.
+ //
+ pOutput = (tACOutputTerminal *)pHeader;
+
+ //
+ // Only CS_INTERFACE descriptors can be a terminal.
+ //
+ if((pHeader->bDescriptorType == USB_DTYPE_CS_INTERFACE) &&
+ (ulTerminal == pOutput->bDescriptorSubtype))
+ {
+ if((pOutput->bDescriptorSubtype == USB_AI_OUTPUT_TERMINAL) ||
+ (pOutput->bDescriptorSubtype == USB_AI_INPUT_TERMINAL))
+
+ {
+ //
+ // If this was the terminal type that was requested, the
+ // return it.
+ //
+ if(pOutput->wTerminalType == ulTerminalType)
+ {
+ return(pHeader);
+ }
+ }
+ else if(pOutput->bDescriptorSubtype == USB_AI_FEATURE_UNIT)
+ {
+ return(pHeader);
+ }
+ }
+
+ //
+ // Decrease the bytes remaining by the size of this descriptor.
+ //
+ lBytesRemaining -= pHeader->bLength;
+
+ //
+ // Move the pointer to the next header.
+ //
+ pHeader = (tDescriptorHeader*)((unsigned long)pHeader +
+ pHeader->bLength);
+ }
+ return((tDescriptorHeader *)0);
+}
+
+//*****************************************************************************
+//
+// This function returns the interface number for the control interface
+// in the structure passed in the pConfigDesc.
+//
+// \param pConfigDescriptor is a pointer to the memory containing a valid
+// configuration descriptor for a device.
+//
+// This function searches a configuration descriptor for a control interface
+// descriptor. The function only search for the first descriptor and then
+// returns when it finds one.
+//
+// \return The first control interface descriptor number for an audio device
+// or INVALID_INTERFACE if no control interface descriptor was found.
+//
+//*****************************************************************************
+static unsigned long
+AudioControlGet(tConfigDescriptor *pConfigDesc)
+{
+ tDescriptorHeader *pHeader;
+ tInterfaceDescriptor *pInterface;
+ unsigned long ulInterface;
+ long lBytes;
+
+ pHeader = (tDescriptorHeader *)pConfigDesc;
+ lBytes = pConfigDesc->wTotalLength;
+
+ //
+ // Initialize the interface number to an invalid value.
+ //
+ ulInterface = INVALID_INTERFACE;
+
+ //
+ // Search the whole configuration descriptor.
+ //
+ while(lBytes > 0)
+ {
+ //
+ // Find an interface descriptor and see if it is a control interface.
+ //
+ if(pHeader->bDescriptorType == USB_DTYPE_INTERFACE)
+ {
+ pInterface = (tInterfaceDescriptor *)pHeader;
+
+ //
+ // If this is the control interface then return the value to the
+ // caller.
+ //
+ if(pInterface->bInterfaceSubClass == USB_ASC_AUDIO_CONTROL)
+ {
+ ulInterface = pInterface->bInterfaceNumber;
+
+ break;
+ }
+ }
+
+ //
+ // Decrease the bytes remaining by the size of this descriptor.
+ //
+ lBytes -= pHeader->bLength;
+
+ //
+ // Move the pointer to the next header.
+ //
+ pHeader = (tDescriptorHeader*)((unsigned long)pHeader +
+ pHeader->bLength);
+ }
+ return(ulInterface);
+}
+
+//*****************************************************************************
+//
+// If it exists, finds the correct audio interface for a given audio format.
+//
+//*****************************************************************************
+static unsigned long
+AudioGetInterface(tUSBHostAudioInstance *pAudioDevice,
+ unsigned short usFormat, unsigned long ulSampleRate,
+ unsigned long ulBytes, unsigned long ulChannels,
+ unsigned long ulFlags)
+{
+ tDescriptorHeader *pHeader;
+ tInterfaceDescriptor *pInterface;
+ tEndpointDescriptor *pINEndpoint, *pOUTEndpoint;
+ tACHeader *pACHeader;
+ tACGeneral *pGeneral;
+ tASFormat *pFormat;
+ tEndpointDescriptor *pEndpoint;
+ unsigned char *pucValue;
+ unsigned long ulValue;
+ long lBytes, lIdx;
+
+ //
+ // Initialize the Interface pointer to null.
+ //
+ pInterface = 0;
+ pINEndpoint = 0;
+ pOUTEndpoint = 0;
+
+ //
+ // Start at the top of the configuration descriptor.
+ //
+ pHeader = (tDescriptorHeader *)pAudioDevice->pDevice->pConfigDescriptor;
+
+ lBytes = pAudioDevice->pDevice->pConfigDescriptor->wTotalLength;
+
+ while(lBytes > 0)
+ {
+ if(pHeader->bDescriptorType == USB_DTYPE_INTERFACE)
+ {
+ //
+ // If a new interface was found and the last one satisfied all
+ // requirements then a valid interface was found so break out.
+ //
+ if(pInterface)
+ {
+ break;
+ }
+
+ //
+ // Get the new interface pointer.
+ //
+ pInterface = (tInterfaceDescriptor *)pHeader;
+
+ //
+ // Reset the endpoints on finding a new interface descriptor.
+ //
+ pINEndpoint = 0;
+ pOUTEndpoint = 0;
+
+ //
+ // If this is not a valid audio streaming interface then reset
+ // the interface pointer to null.
+ //
+ if((pInterface->bNumEndpoints == 0) ||
+ (pInterface->bInterfaceClass != USB_CLASS_AUDIO) ||
+ (pInterface->bInterfaceSubClass != USB_ASC_AUDIO_STREAMING))
+ {
+ pInterface = 0;
+ }
+ }
+ if((pInterface) && (pHeader->bDescriptorType == USB_DTYPE_CS_INTERFACE))
+ {
+ pACHeader = (tACHeader *)pHeader;
+
+ //
+ // If this is a General descriptor the check if the format matches.
+ //
+ if(pACHeader->bDescriptorSubtype == USB_AS_GENERAL)
+ {
+ //
+ // Just save the pointer to the format descriptor.
+ //
+ pGeneral = (tACGeneral *)pHeader;
+
+ //
+ // If this interface has the wrong format then set it to null
+ // so that the rest of this interface is ignored.
+ //
+ if(pGeneral->wFormatTag != usFormat)
+ {
+ pInterface = 0;
+ }
+ }
+ else if(pACHeader->bDescriptorSubtype == USB_AS_FORMAT_TYPE)
+ {
+ pFormat = (tASFormat *)pHeader;
+
+ //
+ // If the number of bytes per sample and number of channels do
+ // not match then reset the interface pointer so that the rest
+ // of this interface is ignored.
+ //
+ if((pFormat->bNrChannels != ulChannels) ||
+ (pFormat->bSubFrameSize != ulBytes))
+ {
+ pInterface = 0;
+ }
+ else
+ {
+ pucValue = &pFormat->tSamFreq;
+
+ //
+ // Attempt to find the sample rate in the sample rate
+ // table for this interface.
+ //
+ for(lIdx = 0; lIdx < pFormat->bSamFreqType; lIdx++)
+ {
+ ulValue = (*((unsigned long *)&pucValue[lIdx * 3]) &
+ 0xffffff);
+
+ if(ulValue == ulSampleRate)
+ {
+ break;
+ }
+ }
+
+ //
+ // If the sample rate was not found then set the interface
+ // pointer to null so that the rest of this interface is
+ // ignored.
+ //
+ if(lIdx == pFormat->bSamFreqType)
+ {
+ pInterface = 0;
+ }
+ }
+ }
+ }
+ else if((pInterface) &&
+ (pHeader->bDescriptorType == USB_DTYPE_ENDPOINT))
+ {
+ pEndpoint = (tEndpointDescriptor *)pHeader;
+
+ //
+ // See what direction is being requested.
+ //
+ if(ulFlags & USBH_AUDIO_FORMAT_IN)
+ {
+ //
+ // If this is an input endpoint and is just a feed back input
+ // then ignore it.
+ //
+ if(pEndpoint->bEndpointAddress & USB_EP_DESC_IN)
+ {
+ if((pEndpoint->bmAttributes & USB_EP_ATTR_USAGE_M)
+ == USB_EP_ATTR_USAGE_FEEDBACK)
+ {
+ pInterface = 0;
+ }
+ else
+ {
+ //
+ // Save this endpoint as a possible valid endpoint
+ //
+ pINEndpoint = pEndpoint;
+ }
+ }
+ }
+ else
+ {
+ //
+ // If this is an output endpoint and is just a feed back input
+ // then ignore it.
+ //
+ if((pEndpoint->bEndpointAddress & USB_EP_DESC_IN) == 0)
+ {
+ if((pEndpoint->bmAttributes & USB_EP_ATTR_USAGE_M)
+ == USB_EP_ATTR_USAGE_FEEDBACK)
+ {
+ pInterface = 0;
+ }
+ else
+ {
+ //
+ // Save this endpoint as a possible valid endpoint;
+ //
+ pOUTEndpoint = pEndpoint;
+ }
+ }
+ }
+ }
+
+ //
+ // Decrease the bytes remaining by the size of this descriptor.
+ //
+ lBytes -= pHeader->bLength;
+
+ //
+ // Move the pointer to the next header.
+ //
+ pHeader = (tDescriptorHeader*)((unsigned long)pHeader +
+ pHeader->bLength);
+ }
+
+ //
+ // If there is still a valid interface then return the values.
+ //
+ if(pInterface)
+ {
+ //
+ // Check a valid IN endpoint descriptor.
+ //
+ if(pINEndpoint)
+ {
+ //
+ // Save the endpoint address.
+ //
+ g_AudioDevice.ucIsochInAddress = pINEndpoint->bEndpointAddress &
+ USB_EP_DESC_NUM_M;
+
+ //
+ // If there is no current pipe then just allocate a new one with
+ // the settings for this interface.
+ //
+ if(g_AudioDevice.ulIsochInPipe == 0)
+ {
+ //
+ // Allocate the USB Pipe for this Isochronous IN end point.
+ //
+ g_AudioDevice.ulIsochInPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_IN_DMA,
+ g_AudioDevice.pDevice,
+ pINEndpoint->wMaxPacketSize,
+ PipeCallbackIN);
+ }
+ else if(g_AudioDevice.usPipeSizeIn < pINEndpoint->wMaxPacketSize)
+ {
+ //
+ // Free the old endpoint and allocate a new one.
+ //
+ USBHCDPipeFree(g_AudioDevice.ulIsochInPipe);
+
+ //
+ // Allocate the USB Pipe for this Isochronous IN end point.
+ //
+ g_AudioDevice.ulIsochInPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_IN_DMA,
+ g_AudioDevice.pDevice,
+ pINEndpoint->wMaxPacketSize,
+ PipeCallbackIN);
+
+ //
+ // Save the new size of the maximum packet size for this
+ // USB pipe.
+ //
+ g_AudioDevice.usPipeSizeIn = pINEndpoint->wMaxPacketSize;
+ }
+
+ //
+ // Configure the USB pipe as a Isochronous IN end point.
+ //
+ USBHCDPipeConfig(g_AudioDevice.ulIsochInPipe,
+ pINEndpoint->wMaxPacketSize,
+ 0,
+ g_AudioDevice.ucIsochInAddress);
+ }
+
+ //
+ // Check a valid OUT endpoint descriptor.
+ //
+ if(pOUTEndpoint)
+ {
+ //
+ // Save the endpoint address.
+ //
+ g_AudioDevice.ucIsochOutAddress = pOUTEndpoint->bEndpointAddress &
+ USB_EP_DESC_NUM_M;
+
+ //
+ // If there is no current pipe then just allocate a new one with
+ // the settings for this interface.
+ //
+ if(g_AudioDevice.ulIsochOutPipe == 0)
+ {
+ //
+ // Allocate the USB Pipe for this Isochronous OUT end point.
+ //
+ g_AudioDevice.ulIsochOutPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_OUT_DMA,
+ g_AudioDevice.pDevice,
+ pOUTEndpoint->wMaxPacketSize,
+ PipeCallbackOUT);
+ }
+ else if(g_AudioDevice.usPipeSizeOut < pOUTEndpoint->wMaxPacketSize)
+ {
+ //
+ // Free the old endpoint and allocate a new one.
+ //
+ USBHCDPipeFree(g_AudioDevice.ulIsochOutPipe);
+
+ //
+ // Allocate the USB Pipe for this Isochronous OUT end point.
+ //
+ g_AudioDevice.ulIsochOutPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_OUT_DMA,
+ g_AudioDevice.pDevice,
+ pOUTEndpoint->wMaxPacketSize,
+ PipeCallbackOUT);
+
+ //
+ // Save the new size of the maximum packet size for this
+ // USB pipe.
+ //
+ g_AudioDevice.usPipeSizeOut = pOUTEndpoint->wMaxPacketSize;
+ }
+
+ //
+ // Configure the USB pipe as a Isochronous OUT end point.
+ //
+ USBHCDPipeConfig(g_AudioDevice.ulIsochOutPipe,
+ pOUTEndpoint->wMaxPacketSize, 0,
+ g_AudioDevice.ucIsochOutAddress);
+ }
+
+ return(pInterface->bInterfaceNumber |
+ (pInterface->bAlternateSetting << INTERFACE_ALTSETTING_S));
+ }
+ return(INVALID_INTERFACE);
+}
+
+//*****************************************************************************
+//
+// This function is used to open an instance of the USB host audio driver.
+//
+// \param pDevice is a pointer to the device information structure.
+//
+// This function attempts to open an instance of the USB host audio driver
+// based on the information contained in the pDevice structure. This call
+// fails if there are not sufficient resources to open the device. The
+// function returns a value that should be passed back into USBHostAudioClose()
+// when the driver is no longer needed.
+//
+// \return The function returns a pointer to a USB host audio driver
+// instance.
+//
+//*****************************************************************************
+static void *
+USBAudioOpen(tUSBHostDevice *pDevice)
+{
+ unsigned long ulTemp;
+ tConfigDescriptor *pConfigDesc;
+
+ //
+ // Don't allow the device to be opened without closing first.
+ //
+ if(g_AudioDevice.pDevice)
+ {
+ return(0);
+ }
+
+ g_AudioDevice.pDevice = pDevice;
+
+ //
+ // Save a shorter name for the configuration descriptor.
+ //
+ pConfigDesc = pDevice->pConfigDescriptor;
+
+ //
+ // Find the input terminal.
+ //
+ g_AudioDevice.pInTerminal =
+ (tACInputTerminal *)AudioTerminalGet(pConfigDesc,
+ USB_AI_INPUT_TERMINAL,
+ USB_TTYPE_STREAMING);
+
+ //
+ // Find the output terminal.
+ //
+ g_AudioDevice.pOutTerminal =
+ (tACOutputTerminal *)AudioTerminalGet(pConfigDesc,
+ USB_AI_OUTPUT_TERMINAL,
+ USB_TTYPE_STREAMING);
+
+ //
+ // Find the feature unit.
+ g_AudioDevice.pFeatureUnit =
+ (tACFeatureUnit *)AudioTerminalGet(pConfigDesc,
+ USB_AI_FEATURE_UNIT,
+ 0);
+
+ //
+ // Need some kind of terminal to send or receive audio from.
+ //
+ if((g_AudioDevice.pOutTerminal == 0) &&
+ (g_AudioDevice.pInTerminal == 0))
+ {
+ return(0);
+ }
+
+ //
+ // Find the Audio control interface.
+ //
+ ulTemp = AudioControlGet(pConfigDesc);
+
+ if(ulTemp == INVALID_INTERFACE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the control interface index and increment the number
+ // of interfaces that have been found.
+ //
+ g_AudioDevice.ucIControl = (unsigned char)ulTemp;
+
+ //
+ // If the call back exists, call it with an Open event.
+ //
+ if(g_AudioDevice.pfnCallback != 0)
+ {
+ g_AudioDevice.pfnCallback((void *)&g_AudioDevice,
+ 0, USBH_AUDIO_EVENT_OPEN);
+ }
+
+ //
+ // If a feature unit was found, save the ID
+ //
+ if(g_AudioDevice.pFeatureUnit != 0)
+ {
+ g_AudioDevice.ucVolumeID = g_AudioDevice.pFeatureUnit->bUnitID;
+ }
+
+ //
+ // Save the device pointer.
+ //
+ g_AudioDevice.pDevice = pDevice;
+
+ //
+ // Allocate the USB Pipe for this Isochronous IN end point.
+ //
+ g_AudioDevice.ulIsochInPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_IN_DMA,
+ g_AudioDevice.pDevice, 256,
+ PipeCallbackIN);
+ g_AudioDevice.usPipeSizeIn = 256;
+
+ //
+ // Allocate the USB Pipe for this Isochronous OUT end point.
+ //
+ g_AudioDevice.ulIsochOutPipe =
+ USBHCDPipeAllocSize(0, USBHCD_PIPE_ISOC_OUT_DMA,
+ g_AudioDevice.pDevice, 256,
+ PipeCallbackOUT);
+ g_AudioDevice.usPipeSizeOut = 256;
+
+ //
+ // Clear the flags.
+ //
+ g_AudioDevice.ulFlags = 0;
+
+ //
+ // Return the only instance of this device.
+ //
+ return(&g_AudioDevice);
+}
+
+//*****************************************************************************
+//
+// This function is used to release an instance of the USB host audio driver.
+//
+// \param pvInstance is an instance pointer that needs to be released.
+//
+// This function frees up any resources in use by the USB host audio
+// driver instance that is passed in. The \e pvInstance pointer should be a
+// valid value that was returned from a call to USBHostAudioOpen().
+//
+// \return None.
+//
+//*****************************************************************************
+static void
+USBAudioClose(void *pvInstance)
+{
+ //
+ // Do nothing if there is not a driver open.
+ //
+ if(g_AudioDevice.pDevice == 0)
+ {
+ return;
+ }
+
+ //
+ // Reset the device pointer.
+ //
+ g_AudioDevice.pDevice = 0;
+
+ //
+ // Free the Isochronous IN pipe.
+ //
+ if(g_AudioDevice.ulIsochInPipe != 0)
+ {
+ USBHCDPipeFree(g_AudioDevice.ulIsochInPipe);
+ }
+
+ //
+ // Free the Isochronous OUT pipe.
+ //
+ if(g_AudioDevice.ulIsochOutPipe != 0)
+ {
+ USBHCDPipeFree(g_AudioDevice.ulIsochOutPipe);
+ }
+
+ //
+ // If the call back exists then call it.
+ //
+ if(g_AudioDevice.pfnCallback != 0)
+ {
+ g_AudioDevice.pfnCallback((void *)&g_AudioDevice,
+ 0, USBH_AUDIO_EVENT_CLOSE);
+ }
+}
+
+//*****************************************************************************
+//
+//! This function should be called before any devices are present to enable
+//! the host audio class driver.
+//!
+//! \param ulIndex is the audio device to open (currently only 0 is supported).
+//! \param pfnCallback is the driver call back for host audio events.
+//!
+//! This function is called to open an instance of a host audio device and
+//! should provide a valid callback function for host audio events in the
+//! \e pfnCallback parameter. This function must be called before the USB
+//! host code can successfully enumerate an audio device.
+//!
+//! \return This function returns the driver instance to use for the other
+//! host audio functions. If there is no instance available at the time of
+//! this call, this function returns zero.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioOpen(unsigned long ulIndex, tUSBHostAudioCallback pfnCallback)
+{
+ //
+ // Only one audio device is supported at this time and on one instance
+ // is supported so if there is already a call back then fail.
+ //
+ if((ulIndex != 0) || (g_AudioDevice.pfnCallback))
+ {
+ return(0);
+ }
+
+ //
+ // Save the call back.
+ //
+ g_AudioDevice.pfnCallback = pfnCallback;
+
+ //
+ // Return the requested device instance.
+ //
+ return((unsigned long)&g_AudioDevice);
+}
+
+//*****************************************************************************
+//
+//! This function should be called to release an audio device instance.
+//!
+//! \param ulInstance is the device instance that is to be released.
+//!
+//! This function is called when a host audio device needs to be released.
+//! This could be in preparation for shutdown or a switch to USB device mode,
+//! for example. Following this call, the audio device is available and can
+//! be opened again using a call to USBHostAudioOpen(). After calling this
+//! function, the host audio driver will no longer provide any callbacks or
+//! accept calls to other audio driver APIs.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+USBHostAudioClose(unsigned long ulInstance)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+
+ //
+ // Get a pointer to the device instance data from the handle.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // Close the audio device.
+ //
+ USBAudioClose((void *)pAudioDevice);
+
+ //
+ // Clear the call back indicating that the device is now closed.
+ //
+ pAudioDevice->pfnCallback = 0;
+}
+
+//*****************************************************************************
+//
+// This function is used to request settings from a given audio interface.
+//
+// \param ulInstance is an instance value for the audio device to access.
+// \param ulInterface is the interface to access.
+// \param ulChannel is the channel number to access.
+// \param ulRequest is the audio device request.
+//
+// This function is used to get volume control parameters from a given
+// interface and on a given channel. The \e ulInterface is the interface to
+// make the request specified by \e ulChannel and \e ulRequest. The
+// \e ulRequest parameter must be one of the USB_AC_GET_* values.
+//
+// \return This function returns the requested value.
+//
+//*****************************************************************************
+static unsigned long
+VolumeSettingGet(unsigned long ulInstance, unsigned long ulInterface,
+ unsigned long ulChannel, unsigned long ulRequest)
+{
+ unsigned long ulValue;
+ tUSBHostAudioInstance *pAudioDevice;
+ tUSBRequest SetupPacket;
+
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ ulValue = 0;
+
+ //
+ // This is a Class specific Interface IN request.
+ //
+ SetupPacket.bmRequestType =
+ USB_RTYPE_DIR_IN | USB_RTYPE_CLASS | USB_RTYPE_INTERFACE;
+
+ //
+ // Request a Device Descriptor.
+ //
+ SetupPacket.bRequest = (ulRequest & 0xff);
+
+ //
+ // Request for a string descriptor.
+ //
+ SetupPacket.wValue = VOLUME_CONTROL | (ulChannel & 0xff);
+
+ //
+ // Set the language ID.
+ //
+ SetupPacket.wIndex = (pAudioDevice->ucVolumeID << 8) |
+ (ulInterface & 0xff);
+
+ //
+ // Only request the space available.
+ //
+ SetupPacket.wLength = 2;
+
+ //
+ // Put the setup packet in the buffer.
+ //
+ USBHCDControlTransfer(0, &SetupPacket, pAudioDevice->pDevice,
+ (unsigned char *)&ulValue, 4,
+ pAudioDevice->pDevice->DeviceDescriptor.bMaxPacketSize0);
+
+ return(ulValue);
+}
+
+//*****************************************************************************
+//
+//! This function is used to get the current volume setting for a given
+//! audio device.
+//!
+//! \param ulInstance is an instance of the USB audio device.
+//! \param ulInterface is the interface number to use to query the current
+//! volume setting.
+//! \param ulChannel is the 0 based channel number to query.
+//!
+//! The function is used to retrieve the current volume setting for an audio
+//! device on the channel specified by \e ulChannel. The \e ulInterface is
+//! ignored for now and should be set to 0 to access the default audio control
+//! interface. The \e ulChannel value starts with 0 which is the master audio
+//! volume control interface. The remaining \e ulChannel values provide
+//! access to various other audio channels, with 1 and 2 being left and right
+//! audio channels.
+//!
+//! \note On devices that do not support volume control interfaces, this
+//! call returns 0, indicating a 0db setting.
+//!
+//! \return Returns the current volume setting for the requested interface.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioVolumeGet(unsigned long ulInstance, unsigned long ulInterface,
+ unsigned long ulChannel)
+{
+ return(VolumeSettingGet(ulInstance, ulInterface, ulChannel,
+ USB_AC_GET_CUR));
+}
+
+//*****************************************************************************
+//
+//! This function is used to get the maximum volume setting for a given
+//! audio device.
+//!
+//! \param ulInstance is an instance of the USB audio device.
+//! \param ulInterface is the interface number to use to query the maximum
+//! volume control value.
+//! \param ulChannel is the 0 based channel number to query.
+//!
+//! The function is used to retrieve the maximum volume setting for an audio
+//! device on the channel specified by \e ulChannel. The \e ulInterface is
+//! ignored for now and should be set to 0 to access the default audio control
+//! interface. The \e ulChannel value starts with 0 which is the master audio
+//! volume control interface. The remaining \e ulChannel values provide
+//! access to various other audio channels, with 1 and 2 being left and right
+//! audio channels.
+//!
+//! \note On devices that do not support volume control interfaces, this
+//! call returns 0, indicating a 0db setting.
+//!
+//! \return Returns the maximum volume setting for the requested interface.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioVolumeMaxGet(unsigned long ulInstance, unsigned long ulInterface,
+ unsigned long ulChannel)
+{
+ return(VolumeSettingGet(ulInstance, ulInterface, ulChannel,
+ USB_AC_GET_MAX));
+}
+
+//*****************************************************************************
+//
+//! This function is used to get the minimum volume setting for a given
+//! audio device.
+//!
+//! \param ulInstance is an instance of the USB audio device.
+//! \param ulInterface is the interface number to use to query the minimum
+//! volume control value.
+//! \param ulChannel is the 0 based channel number to query.
+//!
+//! The function is used to retrieve the minimum volume setting for an audio
+//! device on the channel specified by \e ulChannel. The \e ulInterface is
+//! ignored for now and should be set to 0 to access the default audio control
+//! interface. The \e ulChannel value starts with 0 which is the master audio
+//! volume control interface. The remaining \e ulChannel values provide
+//! access to various other audio channels, with 1 and 2 being left and right
+//! audio channels.
+//!
+//! \note On devices that do not support volume control interfaces, this
+//! call returns 0, indicating a 0db setting.
+//!
+//! \return Returns the minimum volume setting for the requested interface.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioVolumeMinGet(unsigned long ulInstance, unsigned long ulInterface,
+ unsigned long ulChannel)
+{
+ return(VolumeSettingGet(ulInstance, ulInterface, ulChannel,
+ USB_AC_GET_MIN));
+}
+
+//*****************************************************************************
+//
+//! This function is used to get the volume control resolution for a given
+//! audio device.
+//!
+//! \param ulInstance is an instance of the USB audio device.
+//! \param ulInterface is the interface number to use to query the resolution
+//! for the volume control.
+//! \param ulChannel is the 0 based channel number to query.
+//!
+//! The function is used to retrieve the volume control resolution for an audio
+//! device on the channel specified by \e ulChannel. The \e ulInterface is
+//! ignored for now and should be set to 0 to access the default audio control
+//! interface. The \e ulChannel value starts with 0 which is the master audio
+//! volume control interface. The remaining \e ulChannel values provide
+//! access to various other audio channels, with 1 and 2 being left and right
+//! audio channels.
+//!
+//! \note On devices that do not support volume control interfaces, this
+//! call returns 0, indicating a 0db setting.
+//!
+//! \return Returns the volume control resolution for the requested interface.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioVolumeResGet(unsigned long ulInstance, unsigned long ulInterface,
+ unsigned long ulChannel)
+{
+ return(VolumeSettingGet(ulInstance, ulInterface, ulChannel,
+ USB_AC_GET_RES));
+}
+
+//*****************************************************************************
+//
+//! This function is used to set the current volume setting for a given
+//! audio device.
+//!
+//! \param ulInstance is an instance of the USB audio device.
+//! \param ulInterface is the interface number to use to set the current
+//! volume setting.
+//! \param ulChannel is the 0 based channel number to query.
+//! \param ulValue is the value to write to the USB audio device.
+//!
+//! The function is used to set the current volume setting for an audio
+//! device on the channel specified by \e ulChannel. The \e ulInterface is
+//! ignored for now and should be set to 0 to access the default audio control
+//! interface. The \e ulChannel value starts with 0 which is the master audio
+//! volume control interface. The remaining \e ulChannel values provide
+//! access to various other audio channels, with 1 and 2 being left and right
+//! audio channels.
+//!
+//! \note On devices that do not support volume control interfaces, this
+//! call returns 0, indicating a 0db setting.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+USBHostAudioVolumeSet(unsigned long ulInstance, unsigned ulInterface,
+ unsigned long ulChannel, unsigned long ulValue)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+ tUSBRequest SetupPacket;
+
+ //
+ // Create an audio instance pointer.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // This is a Class specific Interface OUT request.
+ //
+ SetupPacket.bmRequestType =
+ USB_RTYPE_DIR_OUT | USB_RTYPE_CLASS | USB_RTYPE_INTERFACE;
+
+ //
+ // Request is to set the current value.
+ //
+ SetupPacket.bRequest = USB_AC_SET_CUR;
+
+ //
+ // Request the volume control.
+ //
+ SetupPacket.wValue = VOLUME_CONTROL | (ulChannel & 0xff);
+
+ //
+ // Set Volume control ID and interface to 0.
+ //
+ SetupPacket.wIndex = pAudioDevice->ucVolumeID << 8;
+
+ //
+ // Only request the space available.
+ //
+ SetupPacket.wLength = 2;
+
+ //
+ // Put the setup packet in the buffer.
+ //
+ USBHCDControlTransfer(0, &SetupPacket, pAudioDevice->pDevice,
+ (unsigned char *)&ulValue, 2,
+ pAudioDevice->pDevice->DeviceDescriptor.bMaxPacketSize0);
+}
+
+//*****************************************************************************
+//
+//! This function is called to determine if an audio format is supported by the
+//! connected USB Audio device.
+//!
+//! \param ulInstance is the device instance for this call.
+//! \param ulSampleRate is the sample rate of the audio stream.
+//! \param ulBits is the number of bits per sample in the audio stream.
+//! \param ulChannels is the number of channels in the audio stream.
+//! \param ulFlags is a set of flags to determine what type of interface to
+//! retrieve.
+//!
+//! This function is called when an application needs to determine which audio
+//! formats are supported by a USB audio device that has been connected. The
+//! \e ulInstance value that is used with this call is the value that was
+//! returned from the USBHostAudioOpen() function. This call checks the
+//! USB audio device to determine if it can support the values provided in the
+//! \e ulSampleRate, \e ulBits, and \e ulChannels values. The \e ulFlags
+//! currently only supports either the \b USBH_AUDIO_FORMAT_IN or
+//! \b USBH_AUDIO_FORMAT_OUT values that indicates if a request is for an
+//! audio input and an audio output. If the format is supported this
+//! function returns zero, and this function returns a non-zero value if the
+//! format is not supported. This function does not set the current output or
+//! input format.
+//!
+//! \return A value of zero indicates the supplied format is supported and
+//! a non-zero value indicates that the format is not supported.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioFormatGet(unsigned long ulInstance, unsigned long ulSampleRate,
+ unsigned long ulBits, unsigned long ulChannels,
+ unsigned long ulFlags)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+
+ //
+ // Get a pointer to the device instance data from the handle.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // Look for the requested format.
+ //
+ if(AudioGetInterface(pAudioDevice, USB_ADF_PCM, ulSampleRate, ulBits>>3,
+ ulChannels, ulFlags) != INVALID_INTERFACE)
+ {
+ return(0);
+ }
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! This function is called to set the current sample rate on an audio
+//! interface.
+//!
+//! \param ulInstance specifies the device instance for this call.
+//! \param ulSampleRate is the sample rate in Hz.
+//! \param ulBits is the number of bits per sample.
+//! \param ulChannels is then number of audio channels.
+//! \param ulFlags is a set of flags that determine the access type.
+//!
+//! This function is called when to set the current audio output or input format
+//! for a USB audio device. The \e ulInstance value that is used with this
+//! call is the value that was returned from the USBHostAudioOpen() function.
+//! The application can use this call to insure that the audio format is
+//! supported and set the format at the same time. If the application is
+//! just checking for supported rates, then it should call the
+//! USBHostAudioFormatGet().
+//!
+//! \note This function must be called before attempting to send or receive
+//! audio with the USBHostAudioPlay() or USBHostAudioRecord() functions.
+//!
+//! \return A non-zero value indicates the supplied format is not supported and
+//! a zero value indicates that the format was supported and has been
+//! configured.
+//
+//*****************************************************************************
+unsigned long
+USBHostAudioFormatSet(unsigned long ulInstance, unsigned long ulSampleRate,
+ unsigned long ulBits, unsigned long ulChannels,
+ unsigned long ulFlags)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+ unsigned long ulInterface;
+
+ //
+ // Get a pointer to the device instance data from the handle.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // Look for the requested format.
+ //
+ ulInterface = AudioGetInterface(pAudioDevice, USB_ADF_PCM, ulSampleRate,
+ ulBits>>3, ulChannels, ulFlags);
+
+ if(ulInterface == INVALID_INTERFACE)
+ {
+ return(1);
+ }
+
+ //
+ // Determine if this is an input or output request.
+ //
+ if(ulFlags & USBH_AUDIO_FORMAT_IN)
+ {
+ //
+ // Get the active interface number and alternate setting for this
+ // format.
+ //
+ pAudioDevice->ucInInterface =
+ (unsigned char)(ulInterface & INTERFACE_NUM_M);
+ pAudioDevice->ucInAltSetting =
+ (unsigned char)((ulInterface & INTERFACE_ALTSETTING_M) >>
+ INTERFACE_ALTSETTING_S);
+ }
+ else
+ {
+ //
+ // Get the active interface number and alternate setting for this
+ // format.
+ //
+ pAudioDevice->ucOutInterface =
+ (unsigned char)(ulInterface & INTERFACE_NUM_M);
+ pAudioDevice->ucOutAltSetting =
+ (unsigned char)((ulInterface & INTERFACE_ALTSETTING_M) >>
+ INTERFACE_ALTSETTING_S);
+ }
+ return(0);
+}
+
+//*****************************************************************************
+//
+//! This function is called to send an audio buffer to the USB audio device.
+//!
+//! \param ulInstance specifies the device instance for this call.
+//! \param pvBuffer is the audio buffer to send.
+//! \param ulSize is the size of the buffer in bytes.
+//! \param pfnCallback is a pointer to a callback function that is called
+//! when the buffer can be used again.
+//!
+//! This function is called when an application needs to schedule a new buffer
+//! for output to the USB audio device. Since this call schedules the transfer
+//! and returns immediately, the application should provide a \e pfnCallback
+//! function to be notified when the buffer can be used again by the
+//! application. The \e pfnCallback function provided is called with the
+//! \e pvBuffer parameter set to the \e pvBuffer provided by this call, the
+//! \e ulParam can be ignored and the \e ulEvent parameter is
+//! \b USB_EVENT_TX_COMPLETE.
+//!
+//! \return This function returns the number of bytes that were scheduled
+//! to be sent. If this function returns zero then there was no USB audio
+//! device present or the request could not be satisfied at this time.
+//
+//*****************************************************************************
+long
+USBHostAudioPlay(unsigned long ulInstance, void *pvBuffer,
+ unsigned long ulSize, tUSBHostAudioCallback pfnCallback)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+ unsigned long ulBytes;
+
+ //
+ // Make sure that there is a device present.
+ //
+ if(g_AudioDevice.pDevice == 0)
+ {
+ return(0);
+ }
+
+ //
+ // Get a pointer to the device instance data from the handle.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // If the audio output interface is not active then select the current
+ // active audio interface.
+ //
+ if(HWREGBITW(&pAudioDevice->ulFlags, AUDIO_FLAG_OUT_ACTIVE) == 0)
+ {
+ //
+ // Indicate the active audio interface has been selected.
+ //
+ HWREGBITW(&pAudioDevice->ulFlags, AUDIO_FLAG_OUT_ACTIVE) = 1;
+
+ //
+ // Configure the USB audio device to use the selected audio interface.
+ //
+ USBHCDSetInterface(0, (unsigned long)pAudioDevice->pDevice,
+ pAudioDevice->ucOutInterface,
+ pAudioDevice->ucOutAltSetting);
+ }
+
+ //
+ // Save the callback function and the buffer pointer.
+ //
+ pAudioDevice->pfnOutCallback = pfnCallback;
+ pAudioDevice->pvOutBuffer = (void *)pvBuffer;
+
+ //
+ // Schedule the data to be written out to the FIFO.
+ //
+ ulBytes = USBHCDPipeSchedule(pAudioDevice->ulIsochOutPipe, pvBuffer,
+ ulSize);
+
+ //
+ // Return the number of bytes scheduled to be sent.
+ //
+ return(ulBytes);
+}
+
+//*****************************************************************************
+//
+//! This function is called to provide an audio buffer to the USB audio device
+//! for audio input.
+//!
+//! \param ulInstance specifies the device instance for this call.
+//! \param pvBuffer is the audio buffer to send.
+//! \param ulSize is the size of the buffer in bytes.
+//! \param pfnCallback is a pointer to a callback function that is called
+//! when the buffer has been filled.
+//!
+//! This function is called when an application needs to schedule a new buffer
+//! for input from the USB audio device. Since this call schedules the
+//! transfer and returns immediately, the application should provide a
+//! \e pfnCallback function to be notified when the buffer has been filled with
+//! audio data. When the \e pfnCallback function is called, the \e pvBuffer
+//! parameter is set to \e pvBuffer provided in this call, the \e ulParam is
+//! the number of valid bytes in the pvBuffer and the \e ulEvent is set to
+//! \b USB_EVENT_RX_AVAILABLE.
+//!
+//! \return This function returns the number of bytes that were scheduled
+//! to be sent. If this function returns zero then there was no USB audio
+//! device present or the device does not support audio input.
+//
+//*****************************************************************************
+long
+USBHostAudioRecord(unsigned long ulInstance, void *pvBuffer,
+ unsigned long ulSize, tUSBHostAudioCallback pfnCallback)
+{
+ tUSBHostAudioInstance *pAudioDevice;
+ unsigned long ulBytes;
+
+ //
+ // Make sure that there is a device present.
+ //
+ if(g_AudioDevice.pDevice == 0)
+ {
+ return(0);
+ }
+
+ //
+ // Get a pointer to the device instance data from the handle.
+ //
+ pAudioDevice = (tUSBHostAudioInstance *)ulInstance;
+
+ //
+ // If the audio input interface is not active then select the current
+ // active audio interface.
+ //
+ if(HWREGBITW(&pAudioDevice->ulFlags, AUDIO_FLAG_IN_ACTIVE) == 0)
+ {
+ //
+ // Indicate the active audio interface has been selected.
+ //
+ HWREGBITW(&pAudioDevice->ulFlags, AUDIO_FLAG_IN_ACTIVE) = 1;
+
+ //
+ // Configure the USB audio device to use the selected audio interface.
+ //
+ USBHCDSetInterface(0, (unsigned long)pAudioDevice->pDevice,
+ pAudioDevice->ucInInterface,
+ pAudioDevice->ucInAltSetting);
+ }
+
+ //
+ // Save the callback function and the buffer pointer.
+ //
+ pAudioDevice->pfnInCallback = pfnCallback;
+ pAudioDevice->pvInBuffer = (void *)pvBuffer;
+
+ //
+ // Schedule the data to be written out to the FIFO.
+ //
+ ulBytes = USBHCDPipeSchedule(pAudioDevice->ulIsochInPipe, pvBuffer, ulSize);
+
+ //
+ // Return the number of bytes scheduled to be sent.
+ //
+ return(ulBytes);
+}
+
+//*****************************************************************************
+//
+// Close the Doxygen group.
+//! @}
+//
+//*****************************************************************************
+
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