/*
* Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 DMAC 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.
*
*/
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <asm/mach-jz4740/dma.h>
#include "virt-dma.h"
#define JZ_DMA_NR_CHANS 6
#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)
enum jz4740_dma_width {
JZ4740_DMA_WIDTH_32BIT = 0,
JZ4740_DMA_WIDTH_8BIT = 1,
JZ4740_DMA_WIDTH_16BIT = 2,
};
enum jz4740_dma_transfer_size {
JZ4740_DMA_TRANSFER_SIZE_4BYTE = 0,
JZ4740_DMA_TRANSFER_SIZE_1BYTE = 1,
JZ4740_DMA_TRANSFER_SIZE_2BYTE = 2,
JZ4740_DMA_TRANSFER_SIZE_16BYTE = 3,
JZ4740_DMA_TRANSFER_SIZE_32BYTE = 4,
};
enum jz4740_dma_flags {
JZ4740_DMA_SRC_AUTOINC = 0x2,
JZ4740_DMA_DST_AUTOINC = 0x1,
};
enum jz4740_dma_mode {
JZ4740_DMA_MODE_SINGLE = 0,
JZ4740_DMA_MODE_BLOCK = 1,
};
struct jz4740_dma_sg {
dma_addr_t addr;
unsigned int len;
};
struct jz4740_dma_desc {
struct virt_dma_desc vdesc;
enum dma_transfer_direction direction;
bool cyclic;
unsigned int num_sgs;
struct jz4740_dma_sg sg[];
};
struct jz4740_dmaengine_chan {
struct virt_dma_chan vchan;
unsigned int id;
dma_addr_t fifo_addr;
unsigned int transfer_shift;
struct jz4740_dma_desc *desc;
unsigned int next_sg;
};
struct jz4740_dma_dev {
struct dma_device ddev;
void __iomem *base;
struct clk *clk;
struct jz4740_dmaengine_chan chan[JZ_DMA_NR_CHANS];
};
static struct jz4740_dma_dev *jz4740_dma_chan_get_dev(
struct jz4740_dmaengine_chan *chan)
{
return container_of(chan->vchan.chan.device, struct jz4740_dma_dev,
ddev);
}
static struct jz4740_dmaengine_chan *to_jz4740_dma_chan(struct dma_chan *c)
{
return container_of(c, struct jz4740_dmaengine_chan, vchan.chan);
}
static struct jz4740_dma_desc *to_jz4740_dma_desc(struct virt_dma_desc *vdesc)
{
return container_of(vdesc, struct jz4740_dma_desc, vdesc);
}
static inline uint32_t jz4740_dma_read(struct jz4740_dma_dev *dmadev,
unsigned int reg)
{
return readl(dmadev->base + reg);
}
static inline void jz4740_dma_write(struct jz4740_dma_dev *dmadev,
unsigned reg, uint32_t val)
{
writel(val, dmadev->base + reg);
}
static inline void jz4740_dma_write_mask(struct jz4740_dma_dev *dmadev,
unsigned int reg, uint32_t val, uint32_t mask)
{
uint32_t tmp;
tmp = jz4740_dma_read(dmadev, reg);
tmp &= ~mask;
tmp |= val;
jz4740_dma_write(dmadev, reg, tmp);
}
static struct jz4740_dma_desc *jz4740_dma_alloc_desc(unsigned int num_sgs)
{
return kzalloc(sizeof(struct jz4740_dma_desc) +
sizeof(struct jz4740_dma_sg) * num_sgs, GFP_ATOMIC);
}
static enum jz4740_dma_width jz4740_dma_width(enum dma_slave_buswidth width)
{
switch (width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
return JZ4740_DMA_WIDTH_8BIT;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
return JZ4740_DMA_WIDTH_16BIT;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
return JZ4740_DMA_WIDTH_32BIT;
default:
return JZ4740_DMA_WIDTH_32BIT;
}
}
static enum jz4740_dma_transfer_size jz4740_dma_maxburst(u32 maxburst)
{
if (maxburst <= 1)
return JZ4740_DMA_TRANSFER_SIZE_1BYTE;
else if (maxburst <= 3)
return JZ4740_DMA_TRANSFER_SIZE_2BYTE;
else if (maxburst <= 15)
return JZ4740_DMA_TRANSFER_SIZE_4BYTE;
else if (maxburst <= 31)
return JZ4740_DMA_TRANSFER_SIZE_16BYTE;
return JZ4740_DMA_TRANSFER_SIZE_32BYTE;
}
static int jz4740_dma_slave_config(struct dma_chan *c,
struct dma_slave_config *config)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
enum jz4740_dma_width src_width;
enum jz4740_dma_width dst_width;
enum jz4740_dma_transfer_size transfer_size;
enum jz4740_dma_flags flags;
uint32_t cmd;
switch (config->direction) {
case DMA_MEM_TO_DEV:
flags = JZ4740_DMA_SRC_AUTOINC;
transfer_size = jz4740_dma_maxburst(config->dst_maxburst);
chan->fifo_addr = config->dst_addr;
break;
case DMA_DEV_TO_MEM:
flags = JZ4740_DMA_DST_AUTOINC;
transfer_size = jz4740_dma_maxburst(config->src_maxburst);
chan->fifo_addr = config->src_addr;
break;
default:
return -EINVAL;
}
src_width = jz4740_dma_width(config->src_addr_width);
dst_width = jz4740_dma_width(config->dst_addr_width);
switch (transfer_size) {
case JZ4740_DMA_TRANSFER_SIZE_2BYTE:
chan->transfer_shift = 1;
break;
case JZ4740_DMA_TRANSFER_SIZE_4BYTE:
chan->transfer_shift = 2;
break;
case JZ4740_DMA_TRANSFER_SIZE_16BYTE:
chan->transfer_shift = 4;
break;
case JZ4740_DMA_TRANSFER_SIZE_32BYTE:
chan->transfer_shift = 5;
break;
default:
chan->transfer_shift = 0;
break;
}
cmd = flags << JZ_DMA_CMD_FLAGS_OFFSET;
cmd |= src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET;
cmd |= dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET;
cmd |= transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET;
cmd |= JZ4740_DMA_MODE_SINGLE << JZ_DMA_CMD_MODE_OFFSET;
cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE;
jz4740_dma_write(dmadev, JZ_REG_DMA_CMD(chan->id), cmd);
jz4740_dma_write(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0);
jz4740_dma_write(dmadev, JZ_REG_DMA_REQ_TYPE(chan->id),
config->slave_id);
return 0;
}
static int jz4740_dma_terminate_all(struct dma_chan *c)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&chan->vchan.lock, flags);
jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
JZ_DMA_STATUS_CTRL_ENABLE);
chan->desc = NULL;
vchan_get_all_descriptors(&chan->vchan, &head);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
vchan_dma_desc_free_list(&chan->vchan, &head);
return 0;
}
static int jz4740_dma_start_transfer(struct jz4740_dmaengine_chan *chan)
{
struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
dma_addr_t src_addr, dst_addr;
struct virt_dma_desc *vdesc;
struct jz4740_dma_sg *sg;
jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
JZ_DMA_STATUS_CTRL_ENABLE);
if (!chan->desc) {
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return 0;
chan->desc = to_jz4740_dma_desc(vdesc);
chan->next_sg = 0;
}
if (chan->next_sg == chan->desc->num_sgs)
chan->next_sg = 0;
sg = &chan->desc->sg[chan->next_sg];
if (chan->desc->direction == DMA_MEM_TO_DEV) {
src_addr = sg->addr;
dst_addr = chan->fifo_addr;
} else {
src_addr = chan->fifo_addr;
dst_addr = sg->addr;
}
jz4740_dma_write(dmadev, JZ_REG_DMA_SRC_ADDR(chan->id), src_addr);
jz4740_dma_write(dmadev, JZ_REG_DMA_DST_ADDR(chan->id), dst_addr);
jz4740_dma_write(dmadev, JZ_REG_DMA_TRANSFER_COUNT(chan->id),
sg->len >> chan->transfer_shift);
chan->next_sg++;
jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->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(dmadev, JZ_REG_DMA_CTRL,
JZ_DMA_CTRL_ENABLE,
JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE);
return 0;
}
static void jz4740_dma_chan_irq(struct jz4740_dmaengine_chan *chan)
{
spin_lock(&chan->vchan.lock);
if (chan->desc) {
if (chan->desc->cyclic) {
vchan_cyclic_callback(&chan->desc->vdesc);
} else {
if (chan->next_sg == chan->desc->num_sgs) {
list_del(&chan->desc->vdesc.node);
vchan_cookie_complete(&chan->desc->vdesc);
chan->desc = NULL;
}
}
}
jz4740_dma_start_transfer(chan);
spin_unlock(&chan->vchan.lock);
}
static irqreturn_t jz4740_dma_irq(int irq, void *devid)
{
struct jz4740_dma_dev *dmadev = devid;
uint32_t irq_status;
unsigned int i;
irq_status = readl(dmadev->base + JZ_REG_DMA_IRQ);
for (i = 0; i < 6; ++i) {
if (irq_status & (1 << i)) {
jz4740_dma_write_mask(dmadev,
JZ_REG_DMA_STATUS_CTRL(i), 0,
JZ_DMA_STATUS_CTRL_ENABLE |
JZ_DMA_STATUS_CTRL_TRANSFER_DONE);
jz4740_dma_chan_irq(&dmadev->chan[i]);
}
}
return IRQ_HANDLED;
}
static void jz4740_dma_issue_pending(struct dma_chan *c)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
unsigned long flags;
spin_lock_irqsave(&chan->vchan.lock, flags);
if (vchan_issue_pending(&chan->vchan) && !chan->desc)
jz4740_dma_start_transfer(chan);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
static struct dma_async_tx_descriptor *jz4740_dma_prep_slave_sg(
struct dma_chan *c, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
struct jz4740_dma_desc *desc;
struct scatterlist *sg;
unsigned int i;
desc = jz4740_dma_alloc_desc(sg_len);
if (!desc)
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
desc->sg[i].addr = sg_dma_address(sg);
desc->sg[i].len = sg_dma_len(sg);
}
desc->num_sgs = sg_len;
desc->direction = direction;
desc->cyclic = false;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static struct dma_async_tx_descriptor *jz4740_dma_prep_dma_cyclic(
struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
struct jz4740_dma_desc *desc;
unsigned int num_periods, i;
if (buf_len % period_len)
return NULL;
num_periods = buf_len / period_len;
desc = jz4740_dma_alloc_desc(num_periods);
if (!desc)
return NULL;
for (i = 0; i < num_periods; i++) {
desc->sg[i].addr = buf_addr;
desc->sg[i].len = period_len;
buf_addr += period_len;
}
desc->num_sgs = num_periods;
desc->direction = direction;
desc->cyclic = true;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static size_t jz4740_dma_desc_residue(struct jz4740_dmaengine_chan *chan,
struct jz4740_dma_desc *desc, unsigned int next_sg)
{
struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
unsigned int residue, count;
unsigned int i;
residue = 0;
for (i = next_sg; i < desc->num_sgs; i++)
residue += desc->sg[i].len;
if (next_sg != 0) {
count = jz4740_dma_read(dmadev,
JZ_REG_DMA_TRANSFER_COUNT(chan->id));
residue += count << chan->transfer_shift;
}
return residue;
}
static enum dma_status jz4740_dma_tx_status(struct dma_chan *c,
dma_cookie_t cookie, struct dma_tx_state *state)
{
struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
struct virt_dma_desc *vdesc;
enum dma_status status;
unsigned long flags;
status = dma_cookie_status(c, cookie, state);
if (status == DMA_COMPLETE || !state)
return status;
spin_lock_irqsave(&chan->vchan.lock, flags);
vdesc = vchan_find_desc(&chan->vchan, cookie);
if (cookie == chan->desc->vdesc.tx.cookie) {
state->residue = jz4740_dma_desc_residue(chan, chan->desc,
chan->next_sg);
} else if (vdesc) {
state->residue = jz4740_dma_desc_residue(chan,
to_jz4740_dma_desc(vdesc), 0);
} else {
state->residue = 0;
}
spin_unlock_irqrestore(&chan->vchan.lock, flags);
return status;
}
static void jz4740_dma_free_chan_resources(struct dma_chan *c)
{
vchan_free_chan_resources(to_virt_chan(c));
}
static void jz4740_dma_desc_free(struct virt_dma_desc *vdesc)
{
kfree(container_of(vdesc, struct jz4740_dma_desc, vdesc));
}
#define JZ4740_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
static int jz4740_dma_probe(struct platform_device *pdev)
{
struct jz4740_dmaengine_chan *chan;
struct jz4740_dma_dev *dmadev;
struct dma_device *dd;
unsigned int i;
struct resource *res;
int ret;
int irq;
dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
if (!dmadev)
return -EINVAL;
dd = &dmadev->ddev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dmadev->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dmadev->base))
return PTR_ERR(dmadev->base);
dmadev->clk = clk_get(&pdev->dev, "dma");
if (IS_ERR(dmadev->clk))
return PTR_ERR(dmadev->clk);
clk_prepare_enable(dmadev->clk);
dma_cap_set(DMA_SLAVE, dd->cap_mask);
dma_cap_set(DMA_CYCLIC, dd->cap_mask);
dd->device_free_chan_resources = jz4740_dma_free_chan_resources;
dd->device_tx_status = jz4740_dma_tx_status;
dd->device_issue_pending = jz4740_dma_issue_pending;
dd->device_prep_slave_sg = jz4740_dma_prep_slave_sg;
dd->device_prep_dma_cyclic = jz4740_dma_prep_dma_cyclic;
dd->device_config = jz4740_dma_slave_config;
dd->device_terminate_all = jz4740_dma_terminate_all;
dd->src_addr_widths = JZ4740_DMA_BUSWIDTHS;
dd->dst_addr_widths = JZ4740_DMA_BUSWIDTHS;
dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
dd->dev = &pdev->dev;
INIT_LIST_HEAD(&dd->channels);
for (i = 0; i < JZ_DMA_NR_CHANS; i++) {
chan = &dmadev->chan[i];
chan->id = i;
chan->vchan.desc_free = jz4740_dma_desc_free;
vchan_init(&chan->vchan, dd);
}
ret = dma_async_device_register(dd);
if (ret)
return ret;
irq = platform_get_irq(pdev, 0);
ret = request_irq(irq, jz4740_dma_irq, 0, dev_name(&pdev->dev), dmadev);
if (ret)
goto err_unregister;
platform_set_drvdata(pdev, dmadev);
return 0;
err_unregister:
dma_async_device_unregister(dd);
return ret;
}
static void jz4740_cleanup_vchan(struct dma_device *dmadev)
{
struct jz4740_dmaengine_chan *chan, *_chan;
list_for_each_entry_safe(chan, _chan,
&dmadev->channels, vchan.chan.device_node) {
list_del(&chan->vchan.chan.device_node);
tasklet_kill(&chan->vchan.task);
}
}
static int jz4740_dma_remove(struct platform_device *pdev)
{
struct jz4740_dma_dev *dmadev = platform_get_drvdata(pdev);
int irq = platform_get_irq(pdev, 0);
free_irq(irq, dmadev);
jz4740_cleanup_vchan(&dmadev->ddev);
dma_async_device_unregister(&dmadev->ddev);
clk_disable_unprepare(dmadev->clk);
return 0;
}
static struct platform_driver jz4740_dma_driver = {
.probe = jz4740_dma_probe,
.remove = jz4740_dma_remove,
.driver = {
.name = "jz4740-dma",
},
};
module_platform_driver(jz4740_dma_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("JZ4740 DMA driver");
MODULE_LICENSE("GPL v2");