linux/drivers/dma/dma-axi-dmac.c

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/*
* Driver for the Analog Devices AXI-DMAC core
*
* Copyright 2013-2015 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* Licensed under the GPL-2.
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <dt-bindings/dma/axi-dmac.h>
#include "dmaengine.h"
#include "virt-dma.h"
/*
* The AXI-DMAC is a soft IP core that is used in FPGA designs. The core has
* various instantiation parameters which decided the exact feature set support
* by the core.
*
* Each channel of the core has a source interface and a destination interface.
* The number of channels and the type of the channel interfaces is selected at
* configuration time. A interface can either be a connected to a central memory
* interconnect, which allows access to system memory, or it can be connected to
* a dedicated bus which is directly connected to a data port on a peripheral.
* Given that those are configuration options of the core that are selected when
* it is instantiated this means that they can not be changed by software at
* runtime. By extension this means that each channel is uni-directional. It can
* either be device to memory or memory to device, but not both. Also since the
* device side is a dedicated data bus only connected to a single peripheral
* there is no address than can or needs to be configured for the device side.
*/
#define AXI_DMAC_REG_IRQ_MASK 0x80
#define AXI_DMAC_REG_IRQ_PENDING 0x84
#define AXI_DMAC_REG_IRQ_SOURCE 0x88
#define AXI_DMAC_REG_CTRL 0x400
#define AXI_DMAC_REG_TRANSFER_ID 0x404
#define AXI_DMAC_REG_START_TRANSFER 0x408
#define AXI_DMAC_REG_FLAGS 0x40c
#define AXI_DMAC_REG_DEST_ADDRESS 0x410
#define AXI_DMAC_REG_SRC_ADDRESS 0x414
#define AXI_DMAC_REG_X_LENGTH 0x418
#define AXI_DMAC_REG_Y_LENGTH 0x41c
#define AXI_DMAC_REG_DEST_STRIDE 0x420
#define AXI_DMAC_REG_SRC_STRIDE 0x424
#define AXI_DMAC_REG_TRANSFER_DONE 0x428
#define AXI_DMAC_REG_ACTIVE_TRANSFER_ID 0x42c
#define AXI_DMAC_REG_STATUS 0x430
#define AXI_DMAC_REG_CURRENT_SRC_ADDR 0x434
#define AXI_DMAC_REG_CURRENT_DEST_ADDR 0x438
#define AXI_DMAC_CTRL_ENABLE BIT(0)
#define AXI_DMAC_CTRL_PAUSE BIT(1)
#define AXI_DMAC_IRQ_SOT BIT(0)
#define AXI_DMAC_IRQ_EOT BIT(1)
#define AXI_DMAC_FLAG_CYCLIC BIT(0)
struct axi_dmac_sg {
dma_addr_t src_addr;
dma_addr_t dest_addr;
unsigned int x_len;
unsigned int y_len;
unsigned int dest_stride;
unsigned int src_stride;
unsigned int id;
};
struct axi_dmac_desc {
struct virt_dma_desc vdesc;
bool cyclic;
unsigned int num_submitted;
unsigned int num_completed;
unsigned int num_sgs;
struct axi_dmac_sg sg[];
};
struct axi_dmac_chan {
struct virt_dma_chan vchan;
struct axi_dmac_desc *next_desc;
struct list_head active_descs;
enum dma_transfer_direction direction;
unsigned int src_width;
unsigned int dest_width;
unsigned int src_type;
unsigned int dest_type;
unsigned int max_length;
unsigned int align_mask;
bool hw_cyclic;
bool hw_2d;
};
struct axi_dmac {
void __iomem *base;
int irq;
struct clk *clk;
struct dma_device dma_dev;
struct axi_dmac_chan chan;
struct device_dma_parameters dma_parms;
};
static struct axi_dmac *chan_to_axi_dmac(struct axi_dmac_chan *chan)
{
return container_of(chan->vchan.chan.device, struct axi_dmac,
dma_dev);
}
static struct axi_dmac_chan *to_axi_dmac_chan(struct dma_chan *c)
{
return container_of(c, struct axi_dmac_chan, vchan.chan);
}
static struct axi_dmac_desc *to_axi_dmac_desc(struct virt_dma_desc *vdesc)
{
return container_of(vdesc, struct axi_dmac_desc, vdesc);
}
static void axi_dmac_write(struct axi_dmac *axi_dmac, unsigned int reg,
unsigned int val)
{
writel(val, axi_dmac->base + reg);
}
static int axi_dmac_read(struct axi_dmac *axi_dmac, unsigned int reg)
{
return readl(axi_dmac->base + reg);
}
static int axi_dmac_src_is_mem(struct axi_dmac_chan *chan)
{
return chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM;
}
static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan)
{
return chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM;
}
static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len)
{
if (len == 0 || len > chan->max_length)
return false;
if ((len & chan->align_mask) != 0) /* Not aligned */
return false;
return true;
}
static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr)
{
if ((addr & chan->align_mask) != 0) /* Not aligned */
return false;
return true;
}
static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
{
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct virt_dma_desc *vdesc;
struct axi_dmac_desc *desc;
struct axi_dmac_sg *sg;
unsigned int flags = 0;
unsigned int val;
val = axi_dmac_read(dmac, AXI_DMAC_REG_START_TRANSFER);
if (val) /* Queue is full, wait for the next SOT IRQ */
return;
desc = chan->next_desc;
if (!desc) {
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return;
list_move_tail(&vdesc->node, &chan->active_descs);
desc = to_axi_dmac_desc(vdesc);
}
sg = &desc->sg[desc->num_submitted];
desc->num_submitted++;
if (desc->num_submitted == desc->num_sgs)
chan->next_desc = NULL;
else
chan->next_desc = desc;
sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);
if (axi_dmac_dest_is_mem(chan)) {
axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->dest_addr);
axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->dest_stride);
}
if (axi_dmac_src_is_mem(chan)) {
axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->src_addr);
axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->src_stride);
}
/*
* If the hardware supports cyclic transfers and there is no callback to
* call, enable hw cyclic mode to avoid unnecessary interrupts.
*/
if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback)
flags |= AXI_DMAC_FLAG_CYCLIC;
axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, sg->y_len - 1);
axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, flags);
axi_dmac_write(dmac, AXI_DMAC_REG_START_TRANSFER, 1);
}
static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan)
{
return list_first_entry_or_null(&chan->active_descs,
struct axi_dmac_desc, vdesc.node);
}
static void axi_dmac_transfer_done(struct axi_dmac_chan *chan,
unsigned int completed_transfers)
{
struct axi_dmac_desc *active;
struct axi_dmac_sg *sg;
active = axi_dmac_active_desc(chan);
if (!active)
return;
if (active->cyclic) {
vchan_cyclic_callback(&active->vdesc);
} else {
do {
sg = &active->sg[active->num_completed];
if (!(BIT(sg->id) & completed_transfers))
break;
active->num_completed++;
if (active->num_completed == active->num_sgs) {
list_del(&active->vdesc.node);
vchan_cookie_complete(&active->vdesc);
active = axi_dmac_active_desc(chan);
}
} while (active);
}
}
static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
{
struct axi_dmac *dmac = devid;
unsigned int pending;
pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_PENDING, pending);
spin_lock(&dmac->chan.vchan.lock);
/* One or more transfers have finished */
if (pending & AXI_DMAC_IRQ_EOT) {
unsigned int completed;
completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
axi_dmac_transfer_done(&dmac->chan, completed);
}
/* Space has become available in the descriptor queue */
if (pending & AXI_DMAC_IRQ_SOT)
axi_dmac_start_transfer(&dmac->chan);
spin_unlock(&dmac->chan.vchan.lock);
return IRQ_HANDLED;
}
static int axi_dmac_terminate_all(struct dma_chan *c)
{
struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&chan->vchan.lock, flags);
axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, 0);
chan->next_desc = NULL;
vchan_get_all_descriptors(&chan->vchan, &head);
list_splice_tail_init(&chan->active_descs, &head);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
vchan_dma_desc_free_list(&chan->vchan, &head);
return 0;
}
static void axi_dmac_issue_pending(struct dma_chan *c)
{
struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
unsigned long flags;
axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, AXI_DMAC_CTRL_ENABLE);
spin_lock_irqsave(&chan->vchan.lock, flags);
if (vchan_issue_pending(&chan->vchan))
axi_dmac_start_transfer(chan);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
{
struct axi_dmac_desc *desc;
desc = kzalloc(sizeof(struct axi_dmac_desc) +
sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
if (!desc)
return NULL;
desc->num_sgs = num_sgs;
return desc;
}
static struct dma_async_tx_descriptor *axi_dmac_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 axi_dmac_chan *chan = to_axi_dmac_chan(c);
struct axi_dmac_desc *desc;
struct scatterlist *sg;
unsigned int i;
if (direction != chan->direction)
return NULL;
desc = axi_dmac_alloc_desc(sg_len);
if (!desc)
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) ||
!axi_dmac_check_len(chan, sg_dma_len(sg))) {
kfree(desc);
return NULL;
}
if (direction == DMA_DEV_TO_MEM)
desc->sg[i].dest_addr = sg_dma_address(sg);
else
desc->sg[i].src_addr = sg_dma_address(sg);
desc->sg[i].x_len = sg_dma_len(sg);
desc->sg[i].y_len = 1;
}
desc->cyclic = false;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static struct dma_async_tx_descriptor *axi_dmac_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 axi_dmac_chan *chan = to_axi_dmac_chan(c);
struct axi_dmac_desc *desc;
unsigned int num_periods, i;
if (direction != chan->direction)
return NULL;
if (!axi_dmac_check_len(chan, buf_len) ||
!axi_dmac_check_addr(chan, buf_addr))
return NULL;
if (period_len == 0 || buf_len % period_len)
return NULL;
num_periods = buf_len / period_len;
desc = axi_dmac_alloc_desc(num_periods);
if (!desc)
return NULL;
for (i = 0; i < num_periods; i++) {
if (direction == DMA_DEV_TO_MEM)
desc->sg[i].dest_addr = buf_addr;
else
desc->sg[i].src_addr = buf_addr;
desc->sg[i].x_len = period_len;
desc->sg[i].y_len = 1;
buf_addr += period_len;
}
desc->cyclic = true;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static struct dma_async_tx_descriptor *axi_dmac_prep_interleaved(
struct dma_chan *c, struct dma_interleaved_template *xt,
unsigned long flags)
{
struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
struct axi_dmac_desc *desc;
size_t dst_icg, src_icg;
if (xt->frame_size != 1)
return NULL;
if (xt->dir != chan->direction)
return NULL;
if (axi_dmac_src_is_mem(chan)) {
if (!xt->src_inc || !axi_dmac_check_addr(chan, xt->src_start))
return NULL;
}
if (axi_dmac_dest_is_mem(chan)) {
if (!xt->dst_inc || !axi_dmac_check_addr(chan, xt->dst_start))
return NULL;
}
dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
if (chan->hw_2d) {
if (!axi_dmac_check_len(chan, xt->sgl[0].size) ||
!axi_dmac_check_len(chan, xt->numf))
return NULL;
if (xt->sgl[0].size + dst_icg > chan->max_length ||
xt->sgl[0].size + src_icg > chan->max_length)
return NULL;
} else {
if (dst_icg != 0 || src_icg != 0)
return NULL;
if (chan->max_length / xt->sgl[0].size < xt->numf)
return NULL;
if (!axi_dmac_check_len(chan, xt->sgl[0].size * xt->numf))
return NULL;
}
desc = axi_dmac_alloc_desc(1);
if (!desc)
return NULL;
if (axi_dmac_src_is_mem(chan)) {
desc->sg[0].src_addr = xt->src_start;
desc->sg[0].src_stride = xt->sgl[0].size + src_icg;
}
if (axi_dmac_dest_is_mem(chan)) {
desc->sg[0].dest_addr = xt->dst_start;
desc->sg[0].dest_stride = xt->sgl[0].size + dst_icg;
}
if (chan->hw_2d) {
desc->sg[0].x_len = xt->sgl[0].size;
desc->sg[0].y_len = xt->numf;
} else {
desc->sg[0].x_len = xt->sgl[0].size * xt->numf;
desc->sg[0].y_len = 1;
}
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static void axi_dmac_free_chan_resources(struct dma_chan *c)
{
vchan_free_chan_resources(to_virt_chan(c));
}
static void axi_dmac_desc_free(struct virt_dma_desc *vdesc)
{
kfree(container_of(vdesc, struct axi_dmac_desc, vdesc));
}
/*
* The configuration stored in the devicetree matches the configuration
* parameters of the peripheral instance and allows the driver to know which
* features are implemented and how it should behave.
*/
static int axi_dmac_parse_chan_dt(struct device_node *of_chan,
struct axi_dmac_chan *chan)
{
u32 val;
int ret;
ret = of_property_read_u32(of_chan, "reg", &val);
if (ret)
return ret;
/* We only support 1 channel for now */
if (val != 0)
return -EINVAL;
ret = of_property_read_u32(of_chan, "adi,source-bus-type", &val);
if (ret)
return ret;
if (val > AXI_DMAC_BUS_TYPE_FIFO)
return -EINVAL;
chan->src_type = val;
ret = of_property_read_u32(of_chan, "adi,destination-bus-type", &val);
if (ret)
return ret;
if (val > AXI_DMAC_BUS_TYPE_FIFO)
return -EINVAL;
chan->dest_type = val;
ret = of_property_read_u32(of_chan, "adi,source-bus-width", &val);
if (ret)
return ret;
chan->src_width = val / 8;
ret = of_property_read_u32(of_chan, "adi,destination-bus-width", &val);
if (ret)
return ret;
chan->dest_width = val / 8;
ret = of_property_read_u32(of_chan, "adi,length-width", &val);
if (ret)
return ret;
if (val >= 32)
chan->max_length = UINT_MAX;
else
chan->max_length = (1ULL << val) - 1;
chan->align_mask = max(chan->dest_width, chan->src_width) - 1;
if (axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
chan->direction = DMA_MEM_TO_MEM;
else if (!axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
chan->direction = DMA_MEM_TO_DEV;
else if (axi_dmac_dest_is_mem(chan) && !axi_dmac_src_is_mem(chan))
chan->direction = DMA_DEV_TO_MEM;
else
chan->direction = DMA_DEV_TO_DEV;
chan->hw_cyclic = of_property_read_bool(of_chan, "adi,cyclic");
chan->hw_2d = of_property_read_bool(of_chan, "adi,2d");
return 0;
}
static int axi_dmac_probe(struct platform_device *pdev)
{
struct device_node *of_channels, *of_chan;
struct dma_device *dma_dev;
struct axi_dmac *dmac;
struct resource *res;
int ret;
dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
if (!dmac)
return -ENOMEM;
dmac->irq = platform_get_irq(pdev, 0);
if (dmac->irq <= 0)
return -EINVAL;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dmac->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dmac->base))
return PTR_ERR(dmac->base);
dmac->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dmac->clk))
return PTR_ERR(dmac->clk);
INIT_LIST_HEAD(&dmac->chan.active_descs);
of_channels = of_get_child_by_name(pdev->dev.of_node, "adi,channels");
if (of_channels == NULL)
return -ENODEV;
for_each_child_of_node(of_channels, of_chan) {
ret = axi_dmac_parse_chan_dt(of_chan, &dmac->chan);
if (ret) {
of_node_put(of_chan);
of_node_put(of_channels);
return -EINVAL;
}
}
of_node_put(of_channels);
pdev->dev.dma_parms = &dmac->dma_parms;
dma_set_max_seg_size(&pdev->dev, dmac->chan.max_length);
dma_dev = &dmac->dma_dev;
dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
dma_dev->device_free_chan_resources = axi_dmac_free_chan_resources;
dma_dev->device_tx_status = dma_cookie_status;
dma_dev->device_issue_pending = axi_dmac_issue_pending;
dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;
dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
dma_dev->device_terminate_all = axi_dmac_terminate_all;
dma_dev->dev = &pdev->dev;
dma_dev->chancnt = 1;
dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width);
dma_dev->directions = BIT(dmac->chan.direction);
dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
INIT_LIST_HEAD(&dma_dev->channels);
dmac->chan.vchan.desc_free = axi_dmac_desc_free;
vchan_init(&dmac->chan.vchan, dma_dev);
ret = clk_prepare_enable(dmac->clk);
if (ret < 0)
return ret;
axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00);
ret = dma_async_device_register(dma_dev);
if (ret)
goto err_clk_disable;
ret = of_dma_controller_register(pdev->dev.of_node,
of_dma_xlate_by_chan_id, dma_dev);
if (ret)
goto err_unregister_device;
ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, 0,
dev_name(&pdev->dev), dmac);
if (ret)
goto err_unregister_of;
platform_set_drvdata(pdev, dmac);
return 0;
err_unregister_of:
of_dma_controller_free(pdev->dev.of_node);
err_unregister_device:
dma_async_device_unregister(&dmac->dma_dev);
err_clk_disable:
clk_disable_unprepare(dmac->clk);
return ret;
}
static int axi_dmac_remove(struct platform_device *pdev)
{
struct axi_dmac *dmac = platform_get_drvdata(pdev);
of_dma_controller_free(pdev->dev.of_node);
free_irq(dmac->irq, dmac);
tasklet_kill(&dmac->chan.vchan.task);
dma_async_device_unregister(&dmac->dma_dev);
clk_disable_unprepare(dmac->clk);
return 0;
}
static const struct of_device_id axi_dmac_of_match_table[] = {
{ .compatible = "adi,axi-dmac-1.00.a" },
{ },
};
static struct platform_driver axi_dmac_driver = {
.driver = {
.name = "dma-axi-dmac",
.of_match_table = axi_dmac_of_match_table,
},
.probe = axi_dmac_probe,
.remove = axi_dmac_remove,
};
module_platform_driver(axi_dmac_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("DMA controller driver for the AXI-DMAC controller");
MODULE_LICENSE("GPL v2");