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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright 2009 by Bob Cousins
*
* 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 <stdbool.h>
#include "config.h"
#include "panic.h"
#include "system.h"
#include "mmu-arm.h"
#include "s3c2440.h"
#include "dma-target.h"
#include "system-target.h"
#define NUM_CHANNELS 4
static int dma_used = 0;
/* Status flags */
#define STATUS_CHANNEL_ACTIVE (1<<0)
static struct dma_channel_state
{
volatile unsigned status;
void (*callback)(void);
} dma_state [NUM_CHANNELS];
struct dma_channel_regs
{
volatile unsigned long disrc;
volatile unsigned long disrcc;
volatile unsigned long didst;
volatile unsigned long didstc;
volatile unsigned long dcon;
volatile unsigned long dstat;
volatile unsigned long dcsrc;
volatile unsigned long dcdst;
volatile unsigned long dmasktrig;
volatile unsigned long reserved [7]; /* pad to 0x40 bytes */
};
struct dma_channel_regs *dma_regs [4] =
{
(struct dma_channel_regs *) &DISRC0,
(struct dma_channel_regs *) &DISRC1,
(struct dma_channel_regs *) &DISRC2,
(struct dma_channel_regs *) &DISRC3
}
;
void dma_init(void)
{
/* TODO */
/* Enable interupt on DMA Finish */
/* Clear pending source */
SRCPND = DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK;
INTPND = DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK;
/* Enable interrupt in controller */
bitclr32(&INTMOD, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
bitclr32(&INTMSK, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
}
void dma_retain(void)
{
/* TODO */
dma_used++;
if(dma_used > 0)
{
/* Enable DMA controller, clock? */
}
}
void dma_release(void)
{
/* TODO */
if (dma_used > 0)
dma_used--;
if(dma_used == 0)
{
/* Disable DMA */
}
}
inline void dma_disable_channel(int channel)
{
struct dma_channel_regs *regs = dma_regs [channel];
/* disable the specified channel */
/* Reset the channel */
regs->dmasktrig |= DMASKTRIG_STOP;
/* Wait for DMA controller to be ready */
while(regs->dmasktrig & DMASKTRIG_ON)
;
while(regs->dstat & DSTAT_STAT_BUSY)
;
}
void dma_enable_channel(int channel, struct dma_request *request)
{
struct dma_channel_regs *regs = dma_regs [channel];
/* TODO - transfer sizes (assumes word) */
if (DMA_GET_SRC(request->source_map, channel) == DMA_INVALID)
panicf ("DMA: invalid channel");
/* setup a transfer on specified channel */
dma_disable_channel (channel);
if((unsigned long)request->source_addr < UNCACHED_BASE_ADDR)
regs->disrc = (unsigned long)request->source_addr + UNCACHED_BASE_ADDR;
else
regs->disrc = (unsigned long)request->source_addr;
regs->disrcc = request->source_control;
if((unsigned long)request->dest_addr < UNCACHED_BASE_ADDR)
regs->didst = (unsigned long)request->dest_addr + UNCACHED_BASE_ADDR;
else
regs->didst = (unsigned long)request->dest_addr;
regs->didstc = request->dest_control;
regs->dcon = request->control | request->count |
DMA_GET_SRC(request->source_map, channel) * DCON_HWSRCSEL;
dma_state [channel].callback = request->callback;
/* Activate the channel */
commit_discard_dcache_range((void *)request->dest_addr, request->count * 4);
dma_state [channel].status |= STATUS_CHANNEL_ACTIVE;
regs->dmasktrig = DMASKTRIG_ON;
if ((request->control & DCON_HW_SEL) == 0)
{
/* Start DMA */
regs->dmasktrig |= DMASKTRIG_SW_TRIG;
}
}
/* ISRs */
static inline void generic_isr (unsigned channel)
{
if (dma_state [channel].status | STATUS_CHANNEL_ACTIVE)
{
if (dma_state [channel].callback)
/* call callback for relevant channel */
dma_state [channel].callback();
dma_state [channel].status &= ~STATUS_CHANNEL_ACTIVE;
}
}
void DMA0(void)
{
generic_isr (0);
/* Ack the interrupt */
SRCPND = DMA0_MASK;
INTPND = DMA0_MASK;
}
void DMA1(void)
{
generic_isr (1);
/* Ack the interrupt */
SRCPND = DMA1_MASK;
INTPND = DMA1_MASK;
}
void DMA2(void)
{
generic_isr (2);
/* Ack the interrupt */
SRCPND = DMA2_MASK;
INTPND = DMA2_MASK;
}
void DMA3(void)
{
generic_isr (3);
/* Ack the interrupt */
SRCPND = DMA3_MASK;
INTPND = DMA3_MASK;
}
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