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linux/arch/mips/jz4740/dma.c
Lars-Peter Clausen 68fcfe7f82 MIPS: JZ4740: Add DMA support. 
Add support for DMA transfers on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:26:15 +01:00

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/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 SoC DMA support
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <asm/mach-jz4740/dma.h>
#include <asm/mach-jz4740/base.h>
#define JZ_REG_DMA_SRC_ADDR(x) (0x00 + (x) * 0x20)
#define JZ_REG_DMA_DST_ADDR(x) (0x04 + (x) * 0x20)
#define JZ_REG_DMA_TRANSFER_COUNT(x) (0x08 + (x) * 0x20)
#define JZ_REG_DMA_REQ_TYPE(x) (0x0C + (x) * 0x20)
#define JZ_REG_DMA_STATUS_CTRL(x) (0x10 + (x) * 0x20)
#define JZ_REG_DMA_CMD(x) (0x14 + (x) * 0x20)
#define JZ_REG_DMA_DESC_ADDR(x) (0x18 + (x) * 0x20)
#define JZ_REG_DMA_CTRL 0x300
#define JZ_REG_DMA_IRQ 0x304
#define JZ_REG_DMA_DOORBELL 0x308
#define JZ_REG_DMA_DOORBELL_SET 0x30C
#define JZ_DMA_STATUS_CTRL_NO_DESC BIT(31)
#define JZ_DMA_STATUS_CTRL_DESC_INV BIT(6)
#define JZ_DMA_STATUS_CTRL_ADDR_ERR BIT(4)
#define JZ_DMA_STATUS_CTRL_TRANSFER_DONE BIT(3)
#define JZ_DMA_STATUS_CTRL_HALT BIT(2)
#define JZ_DMA_STATUS_CTRL_COUNT_TERMINATE BIT(1)
#define JZ_DMA_STATUS_CTRL_ENABLE BIT(0)
#define JZ_DMA_CMD_SRC_INC BIT(23)
#define JZ_DMA_CMD_DST_INC BIT(22)
#define JZ_DMA_CMD_RDIL_MASK (0xf << 16)
#define JZ_DMA_CMD_SRC_WIDTH_MASK (0x3 << 14)
#define JZ_DMA_CMD_DST_WIDTH_MASK (0x3 << 12)
#define JZ_DMA_CMD_INTERVAL_LENGTH_MASK (0x7 << 8)
#define JZ_DMA_CMD_BLOCK_MODE BIT(7)
#define JZ_DMA_CMD_DESC_VALID BIT(4)
#define JZ_DMA_CMD_DESC_VALID_MODE BIT(3)
#define JZ_DMA_CMD_VALID_IRQ_ENABLE BIT(2)
#define JZ_DMA_CMD_TRANSFER_IRQ_ENABLE BIT(1)
#define JZ_DMA_CMD_LINK_ENABLE BIT(0)
#define JZ_DMA_CMD_FLAGS_OFFSET 22
#define JZ_DMA_CMD_RDIL_OFFSET 16
#define JZ_DMA_CMD_SRC_WIDTH_OFFSET 14
#define JZ_DMA_CMD_DST_WIDTH_OFFSET 12
#define JZ_DMA_CMD_TRANSFER_SIZE_OFFSET 8
#define JZ_DMA_CMD_MODE_OFFSET 7
#define JZ_DMA_CTRL_PRIORITY_MASK (0x3 << 8)
#define JZ_DMA_CTRL_HALT BIT(3)
#define JZ_DMA_CTRL_ADDRESS_ERROR BIT(2)
#define JZ_DMA_CTRL_ENABLE BIT(0)
static void __iomem *jz4740_dma_base;
static spinlock_t jz4740_dma_lock;
static inline uint32_t jz4740_dma_read(size_t reg)
{
return readl(jz4740_dma_base + reg);
}
static inline void jz4740_dma_write(size_t reg, uint32_t val)
{
writel(val, jz4740_dma_base + reg);
}
static inline void jz4740_dma_write_mask(size_t reg, uint32_t val, uint32_t mask)
{
uint32_t val2;
val2 = jz4740_dma_read(reg);
val2 &= ~mask;
val2 |= val;
jz4740_dma_write(reg, val2);
}
struct jz4740_dma_chan {
unsigned int id;
void *dev;
const char *name;
enum jz4740_dma_flags flags;
uint32_t transfer_shift;
jz4740_dma_complete_callback_t complete_cb;
unsigned used:1;
};
#define JZ4740_DMA_CHANNEL(_id) { .id = _id }
struct jz4740_dma_chan jz4740_dma_channels[] = {
JZ4740_DMA_CHANNEL(0),
JZ4740_DMA_CHANNEL(1),
JZ4740_DMA_CHANNEL(2),
JZ4740_DMA_CHANNEL(3),
JZ4740_DMA_CHANNEL(4),
JZ4740_DMA_CHANNEL(5),
};
struct jz4740_dma_chan *jz4740_dma_request(void *dev, const char *name)
{
unsigned int i;
struct jz4740_dma_chan *dma = NULL;
spin_lock(&jz4740_dma_lock);
for (i = 0; i < ARRAY_SIZE(jz4740_dma_channels); ++i) {
if (!jz4740_dma_channels[i].used) {
dma = &jz4740_dma_channels[i];
dma->used = 1;
break;
}
}
spin_unlock(&jz4740_dma_lock);
if (!dma)
return NULL;
dma->dev = dev;
dma->name = name;
return dma;
}
EXPORT_SYMBOL_GPL(jz4740_dma_request);
void jz4740_dma_configure(struct jz4740_dma_chan *dma,
const struct jz4740_dma_config *config)
{
uint32_t cmd;
switch (config->transfer_size) {
case JZ4740_DMA_TRANSFER_SIZE_2BYTE:
dma->transfer_shift = 1;
break;
case JZ4740_DMA_TRANSFER_SIZE_4BYTE:
dma->transfer_shift = 2;
break;
case JZ4740_DMA_TRANSFER_SIZE_16BYTE:
dma->transfer_shift = 4;
break;
case JZ4740_DMA_TRANSFER_SIZE_32BYTE:
dma->transfer_shift = 5;
break;
default:
dma->transfer_shift = 0;
break;
}
cmd = config->flags << JZ_DMA_CMD_FLAGS_OFFSET;
cmd |= config->src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET;
cmd |= config->dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET;
cmd |= config->transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET;
cmd |= config->mode << JZ_DMA_CMD_MODE_OFFSET;
cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE;
jz4740_dma_write(JZ_REG_DMA_CMD(dma->id), cmd);
jz4740_dma_write(JZ_REG_DMA_STATUS_CTRL(dma->id), 0);
jz4740_dma_write(JZ_REG_DMA_REQ_TYPE(dma->id), config->request_type);
}
EXPORT_SYMBOL_GPL(jz4740_dma_configure);
void jz4740_dma_set_src_addr(struct jz4740_dma_chan *dma, dma_addr_t src)
{
jz4740_dma_write(JZ_REG_DMA_SRC_ADDR(dma->id), src);
}
EXPORT_SYMBOL_GPL(jz4740_dma_set_src_addr);
void jz4740_dma_set_dst_addr(struct jz4740_dma_chan *dma, dma_addr_t dst)
{
jz4740_dma_write(JZ_REG_DMA_DST_ADDR(dma->id), dst);
}
EXPORT_SYMBOL_GPL(jz4740_dma_set_dst_addr);
void jz4740_dma_set_transfer_count(struct jz4740_dma_chan *dma, uint32_t count)
{
count >>= dma->transfer_shift;
jz4740_dma_write(JZ_REG_DMA_TRANSFER_COUNT(dma->id), count);
}
EXPORT_SYMBOL_GPL(jz4740_dma_set_transfer_count);
void jz4740_dma_set_complete_cb(struct jz4740_dma_chan *dma,
jz4740_dma_complete_callback_t cb)
{
dma->complete_cb = cb;
}
EXPORT_SYMBOL_GPL(jz4740_dma_set_complete_cb);
void jz4740_dma_free(struct jz4740_dma_chan *dma)
{
dma->dev = NULL;
dma->complete_cb = NULL;
dma->used = 0;
}
EXPORT_SYMBOL_GPL(jz4740_dma_free);
void jz4740_dma_enable(struct jz4740_dma_chan *dma)
{
jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id),
JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE,
JZ_DMA_STATUS_CTRL_HALT | JZ_DMA_STATUS_CTRL_NO_DESC |
JZ_DMA_STATUS_CTRL_ENABLE);
jz4740_dma_write_mask(JZ_REG_DMA_CTRL,
JZ_DMA_CTRL_ENABLE,
JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE);
}
EXPORT_SYMBOL_GPL(jz4740_dma_enable);
void jz4740_dma_disable(struct jz4740_dma_chan *dma)
{
jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id), 0,
JZ_DMA_STATUS_CTRL_ENABLE);
}
EXPORT_SYMBOL_GPL(jz4740_dma_disable);
uint32_t jz4740_dma_get_residue(const struct jz4740_dma_chan *dma)
{
uint32_t residue;
residue = jz4740_dma_read(JZ_REG_DMA_TRANSFER_COUNT(dma->id));
return residue << dma->transfer_shift;
}
EXPORT_SYMBOL_GPL(jz4740_dma_get_residue);
static void jz4740_dma_chan_irq(struct jz4740_dma_chan *dma)
{
uint32_t status;
status = jz4740_dma_read(JZ_REG_DMA_STATUS_CTRL(dma->id));
jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id), 0,
JZ_DMA_STATUS_CTRL_ENABLE | JZ_DMA_STATUS_CTRL_TRANSFER_DONE);
if (dma->complete_cb)
dma->complete_cb(dma, 0, dma->dev);
}
static irqreturn_t jz4740_dma_irq(int irq, void *dev_id)
{
uint32_t irq_status;
unsigned int i;
irq_status = readl(jz4740_dma_base + JZ_REG_DMA_IRQ);
for (i = 0; i < 6; ++i) {
if (irq_status & (1 << i))
jz4740_dma_chan_irq(&jz4740_dma_channels[i]);
}
return IRQ_HANDLED;
}
static int jz4740_dma_init(void)
{
unsigned int ret;
jz4740_dma_base = ioremap(JZ4740_DMAC_BASE_ADDR, 0x400);
if (!jz4740_dma_base)
return -EBUSY;
spin_lock_init(&jz4740_dma_lock);
ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL);
if (ret)
printk(KERN_ERR "JZ4740 DMA: Failed to request irq: %d\n", ret);
return ret;
}
arch_initcall(jz4740_dma_init);
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