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>

6 files changed, 1117 insertions, 0 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index eaf78f4e07ce..76859aa2688c 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -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"
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 6126e1c3a875..5bddf6f8790f 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -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
diff --git a/drivers/dma/dw-edma/Kconfig b/drivers/dma/dw-edma/Kconfig
new file mode 100644
index 000000000000..3016bed63589
--- /dev/null
+++ b/drivers/dma/dw-edma/Kconfig
@@ -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.
diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile
new file mode 100644
index 000000000000..322401089891
--- /dev/null
+++ b/drivers/dma/dw-edma/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DW_EDMA)		+= dw-edma.o
+dw-edma-objs			:= dw-edma-core.o
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
new file mode 100644
index 000000000000..c9d032f49dc3
--- /dev/null
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -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>");
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
new file mode 100644
index 000000000000..b6cc90cbc9dc
--- /dev/null
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -0,0 +1,165 @@
+/* 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 */