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/*
* (C) Copyright 2010,2011
* NVIDIA Corporation <www.nvidia.com>
* Copyright 2013 Google Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <inttypes.h>
#include <stddef.h>
#include <stdlib.h>
#include <console/console.h>
#include <arch/io.h>
#include <soc/addressmap.h>
#include "dma.h"
struct apb_dma * const apb_dma = (struct apb_dma *)TEGRA_APB_DMA_BASE;
#define APB_DMA_OFFSET(n) \
(struct apb_dma_channel_regs *)(TEGRA_APB_DMA_BASE + n)
struct apb_dma_channel apb_dma_channels[] = {
{ .num = 0, .regs = APB_DMA_OFFSET(0x1000) },
{ .num = 1, .regs = APB_DMA_OFFSET(0x1040) },
{ .num = 2, .regs = APB_DMA_OFFSET(0x1080) },
{ .num = 3, .regs = APB_DMA_OFFSET(0x10c0) },
{ .num = 4, .regs = APB_DMA_OFFSET(0x1100) },
{ .num = 5, .regs = APB_DMA_OFFSET(0x1140) },
{ .num = 6, .regs = APB_DMA_OFFSET(0x1180) },
{ .num = 7, .regs = APB_DMA_OFFSET(0x11c0) },
{ .num = 8, .regs = APB_DMA_OFFSET(0x1200) },
{ .num = 9, .regs = APB_DMA_OFFSET(0x1240) },
{ .num = 10, .regs = APB_DMA_OFFSET(0x1280) },
{ .num = 11, .regs = APB_DMA_OFFSET(0x12c0) },
{ .num = 12, .regs = APB_DMA_OFFSET(0x1300) },
{ .num = 13, .regs = APB_DMA_OFFSET(0x1340) },
{ .num = 14, .regs = APB_DMA_OFFSET(0x1380) },
{ .num = 15, .regs = APB_DMA_OFFSET(0x13c0) },
{ .num = 16, .regs = APB_DMA_OFFSET(0x1400) },
{ .num = 17, .regs = APB_DMA_OFFSET(0x1440) },
{ .num = 18, .regs = APB_DMA_OFFSET(0x1480) },
{ .num = 19, .regs = APB_DMA_OFFSET(0x14c0) },
{ .num = 20, .regs = APB_DMA_OFFSET(0x1500) },
{ .num = 21, .regs = APB_DMA_OFFSET(0x1540) },
{ .num = 22, .regs = APB_DMA_OFFSET(0x1580) },
{ .num = 23, .regs = APB_DMA_OFFSET(0x15c0) },
{ .num = 24, .regs = APB_DMA_OFFSET(0x1600) },
{ .num = 25, .regs = APB_DMA_OFFSET(0x1640) },
{ .num = 26, .regs = APB_DMA_OFFSET(0x1680) },
{ .num = 27, .regs = APB_DMA_OFFSET(0x16c0) },
{ .num = 28, .regs = APB_DMA_OFFSET(0x1700) },
{ .num = 29, .regs = APB_DMA_OFFSET(0x1740) },
{ .num = 30, .regs = APB_DMA_OFFSET(0x1780) },
{ .num = 31, .regs = APB_DMA_OFFSET(0x17c0) },
};
int dma_busy(struct apb_dma_channel * const channel)
{
/*
* In continuous mode, the BSY_n bit in APB_DMA_STATUS and
* BSY in APBDMACHAN_CHANNEL_n_STA_0 will remain set as '1' so long
* as the channel is enabled. So for this function we'll use the
* DMA_ACTIVITY bit.
*/
return read32(&channel->regs->sta) & APB_STA_DMA_ACTIVITY ? 1 : 0;
}
/* claim a DMA channel */
struct apb_dma_channel * const dma_claim(void)
{
int i;
struct apb_dma_channel_regs *regs = NULL;
/*
* Set global enable bit, otherwise register access to channel
* DMA registers will not be possible.
*/
setbits_le32(&apb_dma->command, APB_COMMAND_GEN);
for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) {
regs = apb_dma_channels[i].regs;
if (!apb_dma_channels[i].in_use) {
u32 status = read32(®s->sta);
if (status & (1 << i)) {
/* FIXME: should this be fatal? */
printk(BIOS_DEBUG, "%s: DMA channel %d busy?\n",
__func__, i);
}
break;
}
}
if (i == ARRAY_SIZE(apb_dma_channels))
return NULL;
apb_dma_channels[i].in_use = 1;
return &apb_dma_channels[i];
}
/* release a DMA channel */
void dma_release(struct apb_dma_channel * const channel)
{
int i;
/* FIXME: make this "thread" friendly */
while (dma_busy(channel))
;
channel->in_use = 0;
/* clear the global enable bit if no channels are in use */
for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) {
if (apb_dma_channels[i].in_use)
return;
}
clrbits_le32(&apb_dma->command, APB_COMMAND_GEN);
}
int dma_start(struct apb_dma_channel * const channel)
{
struct apb_dma_channel_regs *regs = channel->regs;
/* Set ENB bit for this channel */
setbits_le32(®s->csr, APB_CSR_ENB);
return 0;
}
int dma_stop(struct apb_dma_channel * const channel)
{
struct apb_dma_channel_regs *regs = channel->regs;
/* Clear ENB bit for this channel */
clrbits_le32(®s->csr, APB_CSR_ENB);
return 0;
}
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