rockbox/firmware/target/arm/as3525/dma-pl081.c
Rafaël Carré c1f90b1881 Sansa AMS: Use DMA for SD transfers (read and write)
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19211 a1c6a512-1295-4272-9138-f99709370657
2008-11-25 13:38:32 +00:00

96 lines
3.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright © 2008 Rafaël Carré
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "as3525.h"
#include "pl081.h"
#include "dma-target.h"
#include <stdbool.h>
#include "panic.h"
volatile bool dma_finished;
void dma_init(void)
{
/* Enable DMA controller */
CGU_PERI |= CGU_DMA_CLOCK_ENABLE;
DMAC_CONFIGURATION |= (1<<0);
DMAC_SYNC = 0;
VIC_INT_ENABLE |= INTERRUPT_DMAC;
}
void dma_enable_channel(int channel, void *src, void *dst, int peri,
int flow_controller, bool src_inc, bool dst_inc,
size_t size, int nwords)
{
int control = 0;
DMAC_CH_SRC_ADDR(channel) = (int)src;
DMAC_CH_DST_ADDR(channel) = (int)dst;
DMAC_CH_LLI(channel) = 0; /* we use contigous memory, so don't use the LLI */
/* specify address increment */
if(src_inc)
control |= (1<<26);
if(dst_inc)
control |= (1<<27);
/* OF use transfers of 4 * 32 bits words on memory, i2sin, i2sout */
/* OF use transfers of 8 * 32 bits words on SD */
control |= (2<<21) | (2<<18); /* dst/src width = word, 32bit */
control |= (nwords<<15) | (nwords<<12); /* dst/src size */
control |= (size & 0x7ff); /* transfer size */
control |= (1<<31); /* current LLI is expected to trigger terminal count interrupt */
DMAC_CH_CONTROL(channel) = control;
dma_finished = false;
/* only needed if DMAC and Peripheral do not run at the same clock speed */
DMAC_SYNC |= (1<<peri);
/* we set the same peripheral as source and destination because we always
* use memory-to-peripheral or peripheral-to-memory transfers */
DMAC_CH_CONFIGURATION(channel) =
(flow_controller<<11) /* flow controller is peripheral */
| (1<<15) /* terminal count interrupt mask */
| (1<<14) /* interrupt error mask */
| (peri<<6) /* dst peripheral */
| (peri<<1) /* src peripheral */
| (1<<0) /* enable channel */
;
}
/* isr */
void INT_DMAC(void)
{
int channel = (DMAC_INT_STATUS & (1<<0)) ? 0 : 1;
if(DMAC_INT_ERROR_STATUS & (1<<channel))
panicf("DMA error, channel %d", channel);
DMAC_INT_TC_CLEAR |= (1<<channel); /* clear terminal count interrupt */
dma_finished = true; /* TODO : use struct wakeup ? */
}