/**

 * $Id: dmac.c,v 1.2 2006-08-02 04:13:15 nkeynes Exp $

 * 

 * DMA support code

 *

 * Copyright (c) 2006 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include "dma.h"

#include "asic.h"

#define DMA_BASE 0xFFA00000

#define DMA_SAR(c) (DMA_BASE+0x00+(c<<4))

#define DMA_DAR(c) (DMA_BASE+0x04+(c<<4))

#define DMA_TCR(c) (DMA_BASE+0x08+(c<<4))

#define DMA_CHCR(c) (DMA_BASE+0x0C+(c<<4))

#define DMA_OR (DMA_BASE+0x40)

#define ASIC_BASE 0xA05F6000

#define PVR_DMA_DEST  (ASIC_BASE+0x800)

#define PVR_DMA_COUNT (ASIC_BASE+0x804)

#define PVR_DMA_CTL   (ASIC_BASE+0x808)

#define PVR_DMA_REGION (ASIC_BASE+0x884)

void dmac_dump_channel( FILE *f, unsigned int channel )

{

    fprintf( f, "DMAC SAR: %08X  Count: %08X  Ctl: %08X  OR: %08X\n",

	     long_read(DMA_SAR(channel)), long_read(DMA_TCR(channel)), 

	     long_read(DMA_CHCR(channel)), long_read(DMA_OR) );

}

/**

 * Setup the DMAC for a transfer. Assumes 32-byte block transfer.

 * Caller is responsible for making sure no-one else is using the

 * channel already. 

 *

 * @param channel DMA channel to use, 0 to 3

 * @param source source address (if a memory source)

 * @param dest   destination address (if a memory destination)

 * @param length number of bytes to transfer (must be a multiple of

 *               32.

 * @param direction 0 = host to device, 1 = device to host

 */

void dmac_prepare_channel( int channel, uint32_t source, uint32_t dest,

			   uint32_t length, int direction )

{

    uint32_t control;

    if( direction == 0 ) {

	/* DMA Disabled, IRQ disabled, 32 byte transfer, burst mode,

	 * Memory => Device, Source addr increment, dest addr fixed

	 */

	control = 0x000012C0;

    } else {

	/* DMA Disabled, IRQ disabled, 32 byte transfer, burst mode,

	 * Device => Memory, Source addr fixed, dest addr increment

	 */

	control = 0x000043C0;

    }

    long_write( DMA_CHCR(channel), control );

    long_write( DMA_SAR(channel), source );

    long_write( DMA_DAR(channel), dest );

    long_write( DMA_TCR(channel), (length >> 5) );

    control |= 0x0001;

    long_write( DMA_CHCR(channel), control ); /* Enable DMA channel */

    long_write( DMA_OR, 0x8201 ); /* Ensure the DMAC config is set */

}

int pvr_dma_write( unsigned int target, char *buf, int len, int region )

{

    uint32_t addr =(uint32_t)buf;

    int result;

    if( (addr & 0xFFFFFFE0) != addr ) {

	fprintf( stderr, "Address error: Attempting DMA from %08X\n", addr );

	return -1;

    }

    long_write( PVR_DMA_CTL, 0 ); /* Stop PVR dma if it's already running */

    asic_clear();

    dmac_prepare_channel( 2, (uint32_t)buf, 0, len, 0 ); /* Allocate channel 2 */

    long_write( PVR_DMA_DEST, target );

    long_write( PVR_DMA_COUNT, len );

    long_write( PVR_DMA_REGION, region );

    CHECK_IEQUALS( target, long_read(PVR_DMA_DEST) );

    CHECK_IEQUALS( len, long_read(PVR_DMA_COUNT) );

    CHECK_IEQUALS( 0, long_read(PVR_DMA_REGION) );

    CHECK_IEQUALS( (uint32_t)buf, long_read(DMA_SAR(2)) );

    CHECK_IEQUALS( len/32, long_read(DMA_TCR(2)) );

    CHECK_IEQUALS( 0x12C1, long_read(DMA_CHCR(2)) );

    long_write( PVR_DMA_CTL, 1 );

    result = asic_wait(EVENT_PVR_DMA);

    if( result != 0 ) {

	fprintf( stderr, "PVR DMA failed (timeout)\n" );

	asic_dump(stderr);

	fprintf( stderr, "Dest: %08X  Count: %08X  Ctl: %08X\n", long_read(PVR_DMA_DEST),

		 long_read(PVR_DMA_COUNT), long_read(PVR_DMA_CTL) );

	dmac_dump_channel(stderr, 2);

	long_write( PVR_DMA_CTL, 0 );

    }

    CHECK_IEQUALS( 0, long_read(PVR_DMA_CTL) );

    CHECK_IEQUALS( ((uint32_t)buf)+len, long_read(DMA_SAR(2))  );

    CHECK_IEQUALS( 0, long_read(DMA_TCR(2)) );

    CHECK_IEQUALS( 0x12C3, long_read(DMA_CHCR(2)) );

    CHECK_IEQUALS( target, long_read(PVR_DMA_DEST) );

    CHECK_IEQUALS( 0, long_read(PVR_DMA_COUNT) );

    CHECK_IEQUALS( 0, long_read(PVR_DMA_REGION) );

    return result;

}