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dmaengine: Add Synopsys eDMA IP core driver 

Add Synopsys PCIe Endpoint eDMA IP core driver to kernel.

This IP is generally distributed with Synopsys PCIe Endpoint IP (depends
of the use and licensing agreement).

This core driver, initializes and configures the eDMA IP using vma-helpers
functions and dma-engine subsystem.

This driver can be compile as built-in or external module in kernel.

To enable this driver just select DW_EDMA option in kernel configuration,
however it requires and selects automatically DMA_ENGINE and
DMA_VIRTUAL_CHANNELS option too.

In order to transfer data from point A to B as fast as possible this IP
requires a dedicated memory space containing linked list of elements.

All elements of this linked list are continuous and each one describes a
data transfer (source and destination addresses, length and a control
variable).

For the sake of simplicity, lets assume a memory space for channel write
0 which allows about 42 elements.

+---------+
| Desc #0 |-+
+---------+ |
            V
       +----------+
       | Chunk #0 |-+
       |  CB = 1  | |  +----------+  +-----+  +-----------+  +-----+
       +----------+ +->| Burst #0 |->| ... |->| Burst #41 |->| llp |
            |          +----------+  +-----+  +-----------+  +-----+
            V
       +----------+
       | Chunk #1 |-+
       |  CB = 0  | |  +-----------+  +-----+  +-----------+  +-----+
       +----------+ +->| Burst #42 |->| ... |->| Burst #83 |->| llp |
            |          +-----------+  +-----+  +-----------+  +-----+
            V
       +----------+
       | Chunk #2 |-+
       |  CB = 1  | |  +-----------+  +-----+  +------------+  +-----+
       +----------+ +->| Burst #84 |->| ... |->| Burst #125 |->| llp |
            |          +-----------+  +-----+  +------------+  +-----+
            V
       +----------+
       | Chunk #3 |-+
       |  CB = 0  | |  +------------+  +-----+  +------------+  +-----+
       +----------+ +->| Burst #126 |->| ... |->| Burst #129 |->| llp |
                       +------------+  +-----+  +------------+  +-----+

Legend:
 - Linked list, also know as Chunk
 - Linked list element*, also know as Burst *CB*, also know as Change Bit,
it's a control bit (and typically is toggled) that allows to easily
identify and differentiate between the current linked list and the
previous or the next one.
 - LLP, is a special element that indicates the end of the linked list
element stream also informs that the next CB should be toggle

On every last Burst of the Chunk (Burst #41, Burst #83, Burst #125 or
even Burst #129) is set some flags on their control variable (RIE and
LIE bits) that will trigger the send of "done" interruption.

On the interruptions callback, is decided whether to recycle the linked
list memory space by writing a new set of Bursts elements (if still
exists Chunks to transfer) or is considered completed (if there is no
Chunks available to transfer).

On scatter-gather transfer mode, the client will submit a scatter-gather
list of n (on this case 130) elements, that will be divide in multiple
Chunks, each Chunk will have (on this case 42) a limited number of
Bursts and after transferring all Bursts, an interrupt will be
triggered, which will allow to recycle the all linked list dedicated
memory again with the new information relative to the next Chunk and
respective Burst associated and repeat the whole cycle again.

On cyclic transfer mode, the client will submit a buffer pointer, length
of it and number of repetitions, in this case each burst will correspond
directly to each repetition.

Each Burst can describes a data transfer from point A(source) to point
B(destination) with a length that can be from 1 byte up to 4 GB. Since
dedicated the memory space where the linked list will reside is limited,
the whole n burst elements will be organized in several Chunks, that
will be used later to recycle the dedicated memory space to initiate a
new sequence of data transfers.

The whole transfer is considered has completed when it was transferred
all bursts.

Currently this IP has a set well-known register map, which includes
support for legacy and unroll modes. Legacy mode is version of this
register map that has multiplexer register that allows to switch
registers between all write and read channels and the unroll modes
repeats all write and read channels registers with an offset between
them. This register map is called v0.

The IP team is creating a new register map more suitable to the latest
PCIe features, that very likely will change the map register, which this
version will be called v1. As soon as this new version is released by
the IP team the support for this version in be included on this driver.

According to the logic, patches 1, 2 and 3 should be squashed into 1
unique patch, but for the sake of simplicity of review, it was divided
in this 3 patches files.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Gustavo Pimentel 2019-06-04 15:29:22 +02:00 committed by Vinod Koul
parent fb6dda8349
commit e63d79d1ff
7 changed files with 1164 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/dma/Kconfig
View File

@ -665,6 +665,8 @@ source "drivers/dma/qcom/Kconfig"
source "drivers/dma/dw/Kconfig"
source "drivers/dma/dw-edma/Kconfig"
source "drivers/dma/hsu/Kconfig"
source "drivers/dma/sh/Kconfig"

1
drivers/dma/Makefile
View File

@ -29,6 +29,7 @@ obj-$(CONFIG_DMA_SUN4I) += sun4i-dma.o
obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
obj-$(CONFIG_DW_AXI_DMAC) += dw-axi-dmac/
obj-$(CONFIG_DW_DMAC_CORE) += dw/
obj-$(CONFIG_DW_EDMA) += dw-edma/
obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o
obj-$(CONFIG_FSL_DMA) += fsldma.o
obj-$(CONFIG_FSL_EDMA) += fsl-edma.o fsl-edma-common.o

9
drivers/dma/dw-edma/Kconfig Normal file
View File

@ -0,0 +1,9 @@
# SPDX-License-Identifier: GPL-2.0
config DW_EDMA
tristate "Synopsys DesignWare eDMA controller driver"
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
help
Support the Synopsys DesignWare eDMA controller, normally
implemented on endpoints SoCs.

4
drivers/dma/dw-edma/Makefile Normal file
View File

@ -0,0 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_DW_EDMA) += dw-edma.o
dw-edma-objs := dw-edma-core.o

936
drivers/dma/dw-edma/dw-edma-core.c Normal file
View File

@ -0,0 +1,936 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
* Synopsys DesignWare eDMA core driver
*
* Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/pm_runtime.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/dma/edma.h>
#include <linux/pci.h>
#include "dw-edma-core.h"
#include "../dmaengine.h"
#include "../virt-dma.h"
static inline
struct device *dchan2dev(struct dma_chan *dchan)
{
return &dchan->dev->device;
}
static inline
struct device *chan2dev(struct dw_edma_chan *chan)
{
return &chan->vc.chan.dev->device;
}
static inline
struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
{
return container_of(vd, struct dw_edma_desc, vd);
}
static struct dw_edma_burst *dw_edma_alloc_burst(struct dw_edma_chunk *chunk)
{
struct dw_edma_burst *burst;
burst = kzalloc(sizeof(*burst), GFP_NOWAIT);
if (unlikely(!burst))
return NULL;
INIT_LIST_HEAD(&burst->list);
if (chunk->burst) {
/* Create and add new element into the linked list */
chunk->bursts_alloc++;
list_add_tail(&burst->list, &chunk->burst->list);
} else {
/* List head */
chunk->bursts_alloc = 0;
chunk->burst = burst;
}
return burst;
}
static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc)
{
struct dw_edma_chan *chan = desc->chan;
struct dw_edma *dw = chan->chip->dw;
struct dw_edma_chunk *chunk;
chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
if (unlikely(!chunk))
return NULL;
INIT_LIST_HEAD(&chunk->list);
chunk->chan = chan;
/* Toggling change bit (CB) in each chunk, this is a mechanism to
* inform the eDMA HW block that this is a new linked list ready
* to be consumed.
* - Odd chunks originate CB equal to 0
* - Even chunks originate CB equal to 1
*/
chunk->cb = !(desc->chunks_alloc % 2);
chunk->ll_region.paddr = dw->ll_region.paddr + chan->ll_off;
chunk->ll_region.vaddr = dw->ll_region.vaddr + chan->ll_off;
if (desc->chunk) {
/* Create and add new element into the linked list */
desc->chunks_alloc++;
list_add_tail(&chunk->list, &desc->chunk->list);
if (!dw_edma_alloc_burst(chunk)) {
kfree(chunk);
return NULL;
}
} else {
/* List head */
chunk->burst = NULL;
desc->chunks_alloc = 0;
desc->chunk = chunk;
}
return chunk;
}
static struct dw_edma_desc *dw_edma_alloc_desc(struct dw_edma_chan *chan)
{
struct dw_edma_desc *desc;
desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
if (unlikely(!desc))
return NULL;
desc->chan = chan;
if (!dw_edma_alloc_chunk(desc)) {
kfree(desc);
return NULL;
}
return desc;
}
static void dw_edma_free_burst(struct dw_edma_chunk *chunk)
{
struct dw_edma_burst *child, *_next;
/* Remove all the list elements */
list_for_each_entry_safe(child, _next, &chunk->burst->list, list) {
list_del(&child->list);
kfree(child);
chunk->bursts_alloc--;
}
/* Remove the list head */
kfree(child);
chunk->burst = NULL;
}
static void dw_edma_free_chunk(struct dw_edma_desc *desc)
{
struct dw_edma_chunk *child, *_next;
if (!desc->chunk)
return;
/* Remove all the list elements */
list_for_each_entry_safe(child, _next, &desc->chunk->list, list) {
dw_edma_free_burst(child);
list_del(&child->list);
kfree(child);
desc->chunks_alloc--;
}
/* Remove the list head */
kfree(child);
desc->chunk = NULL;
}
static void dw_edma_free_desc(struct dw_edma_desc *desc)
{
dw_edma_free_chunk(desc);
kfree(desc);
}
static void vchan_free_desc(struct virt_dma_desc *vdesc)
{
dw_edma_free_desc(vd2dw_edma_desc(vdesc));
}
static void dw_edma_start_transfer(struct dw_edma_chan *chan)
{
struct dw_edma_chunk *child;
struct dw_edma_desc *desc;
struct virt_dma_desc *vd;
vd = vchan_next_desc(&chan->vc);
if (!vd)
return;
desc = vd2dw_edma_desc(vd);
if (!desc)
return;
child = list_first_entry_or_null(&desc->chunk->list,
struct dw_edma_chunk, list);
if (!child)
return;
dw_edma_v0_core_start(child, !desc->xfer_sz);
desc->xfer_sz += child->ll_region.sz;
dw_edma_free_burst(child);
list_del(&child->list);
kfree(child);
desc->chunks_alloc--;
}
static int dw_edma_device_config(struct dma_chan *dchan,
struct dma_slave_config *config)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
memcpy(&chan->config, config, sizeof(*config));
chan->configured = true;
return 0;
}
static int dw_edma_device_pause(struct dma_chan *dchan)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
int err = 0;
if (!chan->configured)
err = -EPERM;
else if (chan->status != EDMA_ST_BUSY)
err = -EPERM;
else if (chan->request != EDMA_REQ_NONE)
err = -EPERM;
else
chan->request = EDMA_REQ_PAUSE;
return err;
}
static int dw_edma_device_resume(struct dma_chan *dchan)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
int err = 0;
if (!chan->configured) {
err = -EPERM;
} else if (chan->status != EDMA_ST_PAUSE) {
err = -EPERM;
} else if (chan->request != EDMA_REQ_NONE) {
err = -EPERM;
} else {
chan->status = EDMA_ST_BUSY;
dw_edma_start_transfer(chan);
}
return err;
}
static int dw_edma_device_terminate_all(struct dma_chan *dchan)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
int err = 0;
LIST_HEAD(head);
if (!chan->configured) {
/* Do nothing */
} else if (chan->status == EDMA_ST_PAUSE) {
chan->status = EDMA_ST_IDLE;
chan->configured = false;
} else if (chan->status == EDMA_ST_IDLE) {
chan->configured = false;
} else if (dw_edma_v0_core_ch_status(chan) == DMA_COMPLETE) {
/*
* The channel is in a false BUSY state, probably didn't
* receive or lost an interrupt
*/
chan->status = EDMA_ST_IDLE;
chan->configured = false;
} else if (chan->request > EDMA_REQ_PAUSE) {
err = -EPERM;
} else {
chan->request = EDMA_REQ_STOP;
}
return err;
}
static void dw_edma_device_issue_pending(struct dma_chan *dchan)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
unsigned long flags;
spin_lock_irqsave(&chan->vc.lock, flags);
if (chan->configured && chan->request == EDMA_REQ_NONE &&
chan->status == EDMA_ST_IDLE && vchan_issue_pending(&chan->vc)) {
chan->status = EDMA_ST_BUSY;
dw_edma_start_transfer(chan);
}
spin_unlock_irqrestore(&chan->vc.lock, flags);
}
static enum dma_status
dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
struct dw_edma_desc *desc;
struct virt_dma_desc *vd;
unsigned long flags;
enum dma_status ret;
u32 residue = 0;
ret = dma_cookie_status(dchan, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE)
ret = DMA_PAUSED;
if (!txstate)
goto ret_residue;
spin_lock_irqsave(&chan->vc.lock, flags);
vd = vchan_find_desc(&chan->vc, cookie);
if (vd) {
desc = vd2dw_edma_desc(vd);
if (desc)
residue = desc->alloc_sz - desc->xfer_sz;
}
spin_unlock_irqrestore(&chan->vc.lock, flags);
ret_residue:
dma_set_residue(txstate, residue);
return ret;
}
static struct dma_async_tx_descriptor *
dw_edma_device_transfer(struct dw_edma_transfer *xfer)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
enum dma_transfer_direction direction = xfer->direction;
phys_addr_t src_addr, dst_addr;
struct scatterlist *sg = NULL;
struct dw_edma_chunk *chunk;
struct dw_edma_burst *burst;
struct dw_edma_desc *desc;
u32 cnt;
int i;
if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) ||
(direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ))
return NULL;
if (xfer->cyclic) {
if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt)
return NULL;
} else {
if (xfer->xfer.sg.len < 1)
return NULL;
}
if (!chan->configured)
return NULL;
desc = dw_edma_alloc_desc(chan);
if (unlikely(!desc))
goto err_alloc;
chunk = dw_edma_alloc_chunk(desc);
if (unlikely(!chunk))
goto err_alloc;
src_addr = chan->config.src_addr;
dst_addr = chan->config.dst_addr;
if (xfer->cyclic) {
cnt = xfer->xfer.cyclic.cnt;
} else {
cnt = xfer->xfer.sg.len;
sg = xfer->xfer.sg.sgl;
}
for (i = 0; i < cnt; i++) {
if (!xfer->cyclic && !sg)
break;
if (chunk->bursts_alloc == chan->ll_max) {
chunk = dw_edma_alloc_chunk(desc);
if (unlikely(!chunk))
goto err_alloc;
}
burst = dw_edma_alloc_burst(chunk);
if (unlikely(!burst))
goto err_alloc;
if (xfer->cyclic)
burst->sz = xfer->xfer.cyclic.len;
else
burst->sz = sg_dma_len(sg);
chunk->ll_region.sz += burst->sz;
desc->alloc_sz += burst->sz;
if (direction == DMA_DEV_TO_MEM) {
burst->sar = src_addr;
if (xfer->cyclic) {
burst->dar = xfer->xfer.cyclic.paddr;
} else {
burst->dar = sg_dma_address(sg);
/* Unlike the typical assumption by other
* drivers/IPs the peripheral memory isn't
* a FIFO memory, in this case, it's a
* linear memory and that why the source
* and destination addresses are increased
* by the same portion (data length)
*/
src_addr += sg_dma_len(sg);
}
} else {
burst->dar = dst_addr;
if (xfer->cyclic) {
burst->sar = xfer->xfer.cyclic.paddr;
} else {
burst->sar = sg_dma_address(sg);
/* Unlike the typical assumption by other
* drivers/IPs the peripheral memory isn't
* a FIFO memory, in this case, it's a
* linear memory and that why the source
* and destination addresses are increased
* by the same portion (data length)
*/
dst_addr += sg_dma_len(sg);
}
}
if (!xfer->cyclic)
sg = sg_next(sg);
}
return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags);
err_alloc:
if (desc)
dw_edma_free_desc(desc);
return NULL;
}
static struct dma_async_tx_descriptor *
dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
unsigned int len,
enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct dw_edma_transfer xfer;
xfer.dchan = dchan;
xfer.direction = direction;
xfer.xfer.sg.sgl = sgl;
xfer.xfer.sg.len = len;
xfer.flags = flags;
xfer.cyclic = false;
return dw_edma_device_transfer(&xfer);
}
static struct dma_async_tx_descriptor *
dw_edma_device_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t paddr,
size_t len, size_t count,
enum dma_transfer_direction direction,
unsigned long flags)
{
struct dw_edma_transfer xfer;
xfer.dchan = dchan;
xfer.direction = direction;
xfer.xfer.cyclic.paddr = paddr;
xfer.xfer.cyclic.len = len;
xfer.xfer.cyclic.cnt = count;
xfer.flags = flags;
xfer.cyclic = true;
return dw_edma_device_transfer(&xfer);
}
static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
{
struct dw_edma_desc *desc;
struct virt_dma_desc *vd;
unsigned long flags;
dw_edma_v0_core_clear_done_int(chan);
spin_lock_irqsave(&chan->vc.lock, flags);
vd = vchan_next_desc(&chan->vc);
if (vd) {
switch (chan->request) {
case EDMA_REQ_NONE:
desc = vd2dw_edma_desc(vd);
if (desc->chunks_alloc) {
chan->status = EDMA_ST_BUSY;
dw_edma_start_transfer(chan);
} else {
list_del(&vd->node);
vchan_cookie_complete(vd);
chan->status = EDMA_ST_IDLE;
}
break;
case EDMA_REQ_STOP:
list_del(&vd->node);
vchan_cookie_complete(vd);
chan->request = EDMA_REQ_NONE;
chan->status = EDMA_ST_IDLE;
break;
case EDMA_REQ_PAUSE:
chan->request = EDMA_REQ_NONE;
chan->status = EDMA_ST_PAUSE;
break;
default:
break;
}
}
spin_unlock_irqrestore(&chan->vc.lock, flags);
}
static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
{
struct virt_dma_desc *vd;
unsigned long flags;
dw_edma_v0_core_clear_abort_int(chan);
spin_lock_irqsave(&chan->vc.lock, flags);
vd = vchan_next_desc(&chan->vc);
if (vd) {
list_del(&vd->node);
vchan_cookie_complete(vd);
}
spin_unlock_irqrestore(&chan->vc.lock, flags);
chan->request = EDMA_REQ_NONE;
chan->status = EDMA_ST_IDLE;
}
static irqreturn_t dw_edma_interrupt(int irq, void *data, bool write)
{
struct dw_edma_irq *dw_irq = data;
struct dw_edma *dw = dw_irq->dw;
unsigned long total, pos, val;
unsigned long off;
u32 mask;
if (write) {
total = dw->wr_ch_cnt;
off = 0;
mask = dw_irq->wr_mask;
} else {
total = dw->rd_ch_cnt;
off = dw->wr_ch_cnt;
mask = dw_irq->rd_mask;
}
val = dw_edma_v0_core_status_done_int(dw, write ?
EDMA_DIR_WRITE :
EDMA_DIR_READ);
val &= mask;
for_each_set_bit(pos, &val, total) {
struct dw_edma_chan *chan = &dw->chan[pos + off];
dw_edma_done_interrupt(chan);
}
val = dw_edma_v0_core_status_abort_int(dw, write ?
EDMA_DIR_WRITE :
EDMA_DIR_READ);
val &= mask;
for_each_set_bit(pos, &val, total) {
struct dw_edma_chan *chan = &dw->chan[pos + off];
dw_edma_abort_interrupt(chan);
}
return IRQ_HANDLED;
}
static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data)
{
return dw_edma_interrupt(irq, data, true);
}
static inline irqreturn_t dw_edma_interrupt_read(int irq, void *data)
{
return dw_edma_interrupt(irq, data, false);
}
static irqreturn_t dw_edma_interrupt_common(int irq, void *data)
{
dw_edma_interrupt(irq, data, true);
dw_edma_interrupt(irq, data, false);
return IRQ_HANDLED;
}
static int dw_edma_alloc_chan_resources(struct dma_chan *dchan)
{
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
if (chan->status != EDMA_ST_IDLE)
return -EBUSY;
pm_runtime_get(chan->chip->dev);
return 0;
}
static void dw_edma_free_chan_resources(struct dma_chan *dchan)
{
unsigned long timeout = jiffies + msecs_to_jiffies(5000);
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
int ret;
while (time_before(jiffies, timeout)) {
ret = dw_edma_device_terminate_all(dchan);
if (!ret)
break;
if (time_after_eq(jiffies, timeout))
return;
cpu_relax();
};
pm_runtime_put(chan->chip->dev);
}
static int dw_edma_channel_setup(struct dw_edma_chip *chip, bool write,
u32 wr_alloc, u32 rd_alloc)
{
struct dw_edma_region *dt_region;
struct device *dev = chip->dev;
struct dw_edma *dw = chip->dw;
struct dw_edma_chan *chan;
size_t ll_chunk, dt_chunk;
struct dw_edma_irq *irq;
struct dma_device *dma;
u32 i, j, cnt, ch_cnt;
u32 alloc, off_alloc;
int err = 0;
u32 pos;
ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
ll_chunk = dw->ll_region.sz;
dt_chunk = dw->dt_region.sz;
/* Calculate linked list chunk for each channel */
ll_chunk /= roundup_pow_of_two(ch_cnt);
/* Calculate linked list chunk for each channel */
dt_chunk /= roundup_pow_of_two(ch_cnt);
if (write) {
i = 0;
cnt = dw->wr_ch_cnt;
dma = &dw->wr_edma;
alloc = wr_alloc;
off_alloc = 0;
} else {
i = dw->wr_ch_cnt;
cnt = dw->rd_ch_cnt;
dma = &dw->rd_edma;
alloc = rd_alloc;
off_alloc = wr_alloc;
}
INIT_LIST_HEAD(&dma->channels);
for (j = 0; (alloc || dw->nr_irqs == 1) && j < cnt; j++, i++) {
chan = &dw->chan[i];
dt_region = devm_kzalloc(dev, sizeof(*dt_region), GFP_KERNEL);
if (!dt_region)
return -ENOMEM;
chan->vc.chan.private = dt_region;
chan->chip = chip;
chan->id = j;
chan->dir = write ? EDMA_DIR_WRITE : EDMA_DIR_READ;
chan->configured = false;
chan->request = EDMA_REQ_NONE;
chan->status = EDMA_ST_IDLE;
chan->ll_off = (ll_chunk * i);
chan->ll_max = (ll_chunk / EDMA_LL_SZ) - 1;
chan->dt_off = (dt_chunk * i);
dev_vdbg(dev, "L. List:\tChannel %s[%u] off=0x%.8lx, max_cnt=%u\n",
write ? "write" : "read", j,
chan->ll_off, chan->ll_max);
if (dw->nr_irqs == 1)
pos = 0;
else
pos = off_alloc + (j % alloc);
irq = &dw->irq[pos];
if (write)
irq->wr_mask |= BIT(j);
else
irq->rd_mask |= BIT(j);
irq->dw = dw;
memcpy(&chan->msi, &irq->msi, sizeof(chan->msi));
dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n",
write ? "write" : "read", j,
chan->msi.address_hi, chan->msi.address_lo,
chan->msi.data);
chan->vc.desc_free = vchan_free_desc;
vchan_init(&chan->vc, dma);
dt_region->paddr = dw->dt_region.paddr + chan->dt_off;
dt_region->vaddr = dw->dt_region.vaddr + chan->dt_off;
dt_region->sz = dt_chunk;
dev_vdbg(dev, "Data:\tChannel %s[%u] off=0x%.8lx\n",
write ? "write" : "read", j, chan->dt_off);
dw_edma_v0_core_device_config(chan);
}
/* Set DMA channel capabilities */
dma_cap_zero(dma->cap_mask);
dma_cap_set(DMA_SLAVE, dma->cap_mask);
dma_cap_set(DMA_CYCLIC, dma->cap_mask);
dma_cap_set(DMA_PRIVATE, dma->cap_mask);
dma->directions = BIT(write ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV);
dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
dma->chancnt = cnt;
/* Set DMA channel callbacks */
dma->dev = chip->dev;
dma->device_alloc_chan_resources = dw_edma_alloc_chan_resources;
dma->device_free_chan_resources = dw_edma_free_chan_resources;
dma->device_config = dw_edma_device_config;
dma->device_pause = dw_edma_device_pause;
dma->device_resume = dw_edma_device_resume;
dma->device_terminate_all = dw_edma_device_terminate_all;
dma->device_issue_pending = dw_edma_device_issue_pending;
dma->device_tx_status = dw_edma_device_tx_status;
dma->device_prep_slave_sg = dw_edma_device_prep_slave_sg;
dma->device_prep_dma_cyclic = dw_edma_device_prep_dma_cyclic;
dma_set_max_seg_size(dma->dev, U32_MAX);
/* Register DMA device */
err = dma_async_device_register(dma);
return err;
}
static inline void dw_edma_dec_irq_alloc(int *nr_irqs, u32 *alloc, u16 cnt)
{
if (*nr_irqs && *alloc < cnt) {
(*alloc)++;
(*nr_irqs)--;
}
}
static inline void dw_edma_add_irq_mask(u32 *mask, u32 alloc, u16 cnt)
{
while (*mask * alloc < cnt)
(*mask)++;
}
static int dw_edma_irq_request(struct dw_edma_chip *chip,
u32 *wr_alloc, u32 *rd_alloc)
{
struct device *dev = chip->dev;
struct dw_edma *dw = chip->dw;
u32 wr_mask = 1;
u32 rd_mask = 1;
int i, err = 0;
u32 ch_cnt;
ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
if (dw->nr_irqs < 1)
return -EINVAL;
if (dw->nr_irqs == 1) {
/* Common IRQ shared among all channels */
err = request_irq(pci_irq_vector(to_pci_dev(dev), 0),
dw_edma_interrupt_common,
IRQF_SHARED, dw->name, &dw->irq[0]);
if (err) {
dw->nr_irqs = 0;
return err;
}
get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), 0),
&dw->irq[0].msi);
} else {
/* Distribute IRQs equally among all channels */
int tmp = dw->nr_irqs;
while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) {
dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt);
dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt);
}
dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt);
dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
err = request_irq(pci_irq_vector(to_pci_dev(dev), i),
i < *wr_alloc ?
dw_edma_interrupt_write :
dw_edma_interrupt_read,
IRQF_SHARED, dw->name,
&dw->irq[i]);
if (err) {
dw->nr_irqs = i;
return err;
}
get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), i),
&dw->irq[i].msi);
}
dw->nr_irqs = i;
}
return err;
}
int dw_edma_probe(struct dw_edma_chip *chip)
{
struct device *dev = chip->dev;
struct dw_edma *dw = chip->dw;
u32 wr_alloc = 0;
u32 rd_alloc = 0;
int i, err;
raw_spin_lock_init(&dw->lock);
/* Find out how many write channels are supported by hardware */
dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
if (!dw->wr_ch_cnt)
return -EINVAL;
/* Find out how many read channels are supported by hardware */
dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
if (!dw->rd_ch_cnt)
return -EINVAL;
dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
dw->wr_ch_cnt, dw->rd_ch_cnt);
/* Allocate channels */
dw->chan = devm_kcalloc(dev, dw->wr_ch_cnt + dw->rd_ch_cnt,
sizeof(*dw->chan), GFP_KERNEL);
if (!dw->chan)
return -ENOMEM;
snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%d", chip->id);
/* Disable eDMA, only to establish the ideal initial conditions */
dw_edma_v0_core_off(dw);
/* Request IRQs */
err = dw_edma_irq_request(chip, &wr_alloc, &rd_alloc);
if (err)
return err;
/* Setup write channels */
err = dw_edma_channel_setup(chip, true, wr_alloc, rd_alloc);
if (err)
goto err_irq_free;
/* Setup read channels */
err = dw_edma_channel_setup(chip, false, wr_alloc, rd_alloc);
if (err)
goto err_irq_free;
/* Power management */
pm_runtime_enable(dev);
/* Turn debugfs on */
dw_edma_v0_core_debugfs_on(chip);
return 0;
err_irq_free:
for (i = (dw->nr_irqs - 1); i >= 0; i--)
free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]);
dw->nr_irqs = 0;
return err;
}
EXPORT_SYMBOL_GPL(dw_edma_probe);
int dw_edma_remove(struct dw_edma_chip *chip)
{
struct dw_edma_chan *chan, *_chan;
struct device *dev = chip->dev;
struct dw_edma *dw = chip->dw;
int i;
/* Disable eDMA */
dw_edma_v0_core_off(dw);
/* Free irqs */
for (i = (dw->nr_irqs - 1); i >= 0; i--)
free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]);
/* Power management */
pm_runtime_disable(dev);
list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels,
vc.chan.device_node) {
list_del(&chan->vc.chan.device_node);
tasklet_kill(&chan->vc.task);
}
list_for_each_entry_safe(chan, _chan, &dw->rd_edma.channels,
vc.chan.device_node) {
list_del(&chan->vc.chan.device_node);
tasklet_kill(&chan->vc.task);
}
/* Deregister eDMA device */
dma_async_device_unregister(&dw->wr_edma);
dma_async_device_unregister(&dw->rd_edma);
/* Turn debugfs off */
dw_edma_v0_core_debugfs_off();
return 0;
}
EXPORT_SYMBOL_GPL(dw_edma_remove);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Synopsys DesignWare eDMA controller core driver");
MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@synopsys.com>");

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drivers/dma/dw-edma/dw-edma-core.h Normal file
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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
* Synopsys DesignWare eDMA core driver
*
* Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
*/
#ifndef _DW_EDMA_CORE_H
#define _DW_EDMA_CORE_H
#include <linux/msi.h>
#include <linux/dma/edma.h>
#include "../virt-dma.h"
#define EDMA_LL_SZ 24
enum dw_edma_dir {
EDMA_DIR_WRITE = 0,
EDMA_DIR_READ
};
enum dw_edma_mode {
EDMA_MODE_LEGACY = 0,
EDMA_MODE_UNROLL
};
enum dw_edma_request {
EDMA_REQ_NONE = 0,
EDMA_REQ_STOP,
EDMA_REQ_PAUSE
};
enum dw_edma_status {
EDMA_ST_IDLE = 0,
EDMA_ST_PAUSE,
EDMA_ST_BUSY
};
struct dw_edma_chan;
struct dw_edma_chunk;
struct dw_edma_burst {
struct list_head list;
u64 sar;
u64 dar;
u32 sz;
};
struct dw_edma_region {
phys_addr_t paddr;
dma_addr_t vaddr;
size_t sz;
};
struct dw_edma_chunk {
struct list_head list;
struct dw_edma_chan *chan;
struct dw_edma_burst *burst;
u32 bursts_alloc;
u8 cb;
struct dw_edma_region ll_region; /* Linked list */
};
struct dw_edma_desc {
struct virt_dma_desc vd;
struct dw_edma_chan *chan;
struct dw_edma_chunk *chunk;
u32 chunks_alloc;
u32 alloc_sz;
u32 xfer_sz;
};
struct dw_edma_chan {
struct virt_dma_chan vc;
struct dw_edma_chip *chip;
int id;
enum dw_edma_dir dir;
off_t ll_off;
u32 ll_max;
off_t dt_off;
struct msi_msg msi;
enum dw_edma_request request;
enum dw_edma_status status;
u8 configured;
struct dma_slave_config config;
};
struct dw_edma_irq {
struct msi_msg msi;
u32 wr_mask;
u32 rd_mask;
struct dw_edma *dw;
};
struct dw_edma {
char name[20];
struct dma_device wr_edma;
u16 wr_ch_cnt;
struct dma_device rd_edma;
u16 rd_ch_cnt;
struct dw_edma_region rg_region; /* Registers */
struct dw_edma_region ll_region; /* Linked list */
struct dw_edma_region dt_region; /* Data */
struct dw_edma_irq *irq;
int nr_irqs;
u32 version;
enum dw_edma_mode mode;
struct dw_edma_chan *chan;
const struct dw_edma_core_ops *ops;
raw_spinlock_t lock; /* Only for legacy */
};
struct dw_edma_sg {
struct scatterlist *sgl;
unsigned int len;
};
struct dw_edma_cyclic {
dma_addr_t paddr;
size_t len;
size_t cnt;
};
struct dw_edma_transfer {
struct dma_chan *dchan;
union dw_edma_xfer {
struct dw_edma_sg sg;
struct dw_edma_cyclic cyclic;
} xfer;
enum dma_transfer_direction direction;
unsigned long flags;
bool cyclic;
};
static inline
struct dw_edma_chan *vc2dw_edma_chan(struct virt_dma_chan *vc)
{
return container_of(vc, struct dw_edma_chan, vc);
}
static inline
struct dw_edma_chan *dchan2dw_edma_chan(struct dma_chan *dchan)
{
return vc2dw_edma_chan(to_virt_chan(dchan));
}
#endif /* _DW_EDMA_CORE_H */

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
* Synopsys DesignWare eDMA core driver
*
* Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
*/
#ifndef _DW_EDMA_H
#define _DW_EDMA_H
#include <linux/device.h>
#include <linux/dmaengine.h>
struct dw_edma;
/**
* struct dw_edma_chip - representation of DesignWare eDMA controller hardware
* @dev: struct device of the eDMA controller
* @id: instance ID
* @irq: irq line
* @dw: struct dw_edma that is filed by dw_edma_probe()
*/
struct dw_edma_chip {
struct device *dev;
int id;
int irq;
struct dw_edma *dw;
};
/* Export to the platform drivers */
#if IS_ENABLED(CONFIG_DW_EDMA)
int dw_edma_probe(struct dw_edma_chip *chip);
int dw_edma_remove(struct dw_edma_chip *chip);
#else
static inline int dw_edma_probe(struct dw_edma_chip *chip)
{
return -ENODEV;
}
static inline int dw_edma_remove(struct dw_edma_chip *chip)
{
return 0;
}
#endif /* CONFIG_DW_EDMA */
#endif /* _DW_EDMA_H */