csdma.c

Ep93XX TionProV2 BSP

//**********************************************************************
//                                                                      
// Filename: CsDma.c
//                                                                      
// Description: 
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Use of this source code is subject to the terms of the Cirrus end-user
// license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
// If you did not accept the terms of the EULA, you are not authorized to 
// use this source code. For a copy of the EULA, please see the 
// EULA.RTF on your install media.
//
// Copyright(c) Cirrus Logic Corporation 2005, All Rights Reserved                       
//                                                                      
//**********************************************************************

#include "csdma.h"

//
// Global pointer to the virtual memory starting address of DMA buffers
//
static DWORD g_pvDmaVirtualBase;
static DWORD g_CurrVirMemAddr;
static DWORD VirtualToPhysAddress(DWORD Virtual);

//****************************************************************************
// DMAInitMem()
//****************************************************************************
BOOL  DMAInitMem(PCHIP pChip)
{
    BOOL status=TRUE;

    g_pvDmaVirtualBase = CS8950_VIRTUAL_MEMORY;
    g_CurrVirMemAddr = CS8950_VIRTUAL_MEMORY;

    memset((PVOID)g_pvDmaVirtualBase, 0, CS8950_MEMORY_SIZE);

    return status;
}



//****************************************************************************
// DMARelMem()
//****************************************************************************
void DMARelMem(PCHIP pChip) 
{
    g_pvDmaVirtualBase = CS8950_VIRTUAL_MEMORY;
    g_CurrVirMemAddr = CS8950_VIRTUAL_MEMORY;
}

//****************************************************************************
// VirtualToPhysAddress()
//****************************************************************************
static DWORD VirtualToPhysAddress(DWORD addrVirtual)
{
    //
    // Make sure that the given virtual address is within the range of our buffer.
    //
    ASSERT((addrVirtual >= g_pvDmaVirtualBase) && 
           (addrVirtual < (g_pvDmaVirtualBase + CS8950_MEMORY_SIZE)));

    //
    // Physical address is the base physical address plus the offset 
    // in the virtual address space. (Make this more flexible later.)
    //
    return (addrVirtual + (ULONG)CS8950_PHYSICAL_MEMORY - (ULONG)CS8950_VIRTUAL_MEMORY);
}




/*************************************************************************
*
* VosAllocSharedMemory()
*
*************************************************************************/
BOOL VosAllocSharedMemory
(
    PCHIP   pChip, 
    WORD    Size,
    PVOID   *ppMemory,
    DWORD   *pPhysAddr
) 
{
    *ppMemory=(PVOID) g_CurrVirMemAddr;
    *pPhysAddr=VirtualToPhysAddress(g_CurrVirMemAddr);
    g_CurrVirMemAddr += (DWORD)Size;

    //The address must start with 32 bits aligment
    switch (g_CurrVirMemAddr & 3 ) 
    {
        case 1 :
            g_CurrVirMemAddr += 3;
            break;
        case 2 :
            g_CurrVirMemAddr += 2;
            break;
        case 3 :
            g_CurrVirMemAddr += 1;
            break;
        default:  // do nothing
            break;
    }

    return TRUE;

}