Certain users can not use right now the DMAengine API due to missing
features in the core. Prime example is Networking.
These users can use the glue layer interface to avoid misuse of DMAengine
API and when the core gains the needed features they can be converted to
use generic API.
The most prominent features the glue layer clients are depending on:
- most PSI-L native peripheral use extra rflow ranges on a receive channel
and depending on the peripheral's configuration packets from a single
free descriptor ring is going to be received to different receive ring
- it is also possible to have different free descriptor rings per rflow
and an rflow can also support 4 additional free descriptor ring based
on the size of the incoming packet
- out of order completion of descriptors on a channel
- when we have several queues to handle different priority packets the
descriptors will be completed 'out-of-order'
- the notion of prep_slave_sg is not matching with what the streaming type
of operation is demanding for networking
- Streaming type of operation
- Ability to fill the free descriptor ring with descriptors in
anticipation of incoming traffic and when a packet arrives UDMAP will
form a packet and gives it to the client driver
- the descriptors are not backed with exact size data buffers as we don't
know the size of the packet we will receive, but as a generic pool of
buffers to be used by the receive channel
- NAPI type of operation (polling instead of interrupt driven transfer)
- without this we can not sustain gigabit speeds and we need to support NAPI
- not to limit this to networking, but other high performance operations
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Link: https://lore.kernel.org/r/20191223110458.30766-12-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
In K3 architecture the DMA operates within threads. One end of the thread
is UDMAP, the other is on the peripheral side.
The UDMAP channel configuration depends on the needs of the remote
endpoint and it can be differ from peripheral to peripheral.
This patch adds database for am654 and j721e and small API to fetch the
PSI-L endpoint configuration from the database which should only used by
the DMA driver(s).
Another API is added for native peripherals to give possibility to pass new
configuration for the threads they are using, which is needed to be able to
handle changes caused by different firmware loaded for the peripheral for
example.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Link: https://lore.kernel.org/r/20191223110458.30766-9-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The Spreadtrum Audio compress offload mode will use 2-stage DMA transfer
to save power. That means we can request 2 dma channels, one for source
channel, and another one for destination channel. Once the source channel's
transaction is done, it will trigger the destination channel's transaction
automatically by hardware signal.
In this case, the source channel will transfer data from IRAM buffer to
the DSP fifo to decoding/encoding, once IRAM buffer is empty by transferring
done, the destination channel will start to transfer data from DDR buffer
to IRAM buffer. Since the destination channel will use link-list mode to
fill the IRAM data, and IRAM buffer is allocated by 32K, and DDR buffer
is larger to 2M, that means we need lots of link-list nodes to do a cyclic
transfer, instead wasting lots of link-list memory, we can use wrap address
support to reduce link-list node number, which means when the transfer
address reaches the wrap address, the transfer address will jump to the
wrap_to address specified by wrap_to register, and only 2 link-list nodes
can do a cyclic transfer to transfer data from DDR to IRAM.
Thus this patch adds wrap address to support this case.
[Baolin Wang changes the commit message]
Signed-off-by: Eric Long <eric.long@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Link: https://lore.kernel.org/r/85a5484bc1f3dd53ce6f92700ad8b35f30a0b096.1571812029.git.baolin.wang@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
- Add support in dmaengine core to do device node checks for DT devices
and update bunch of drivers to use that and remove open coding from
drivers
- New driver/driver support for new hardware, namely:
- MediaTek UART APDMA
- Freescale i.mx7ulp edma2
- Synopsys eDMA IP core version 0
- Allwinner H6 DMA
- Updates to axi-dma and support for interleaved cyclic transfers
- Greg's debugfs return value check removals on drivers
- Updates to stm32-dma, hsu, dw, pl330, tegra drivers
* tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
dmaengine: Revert "dmaengine: fsl-edma: add i.mx7ulp edma2 version support"
dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback
Documentation: dmaengine: clean up description of dmatest usage
dmaengine: tegra210-adma: remove PM_CLK dependency
dmaengine: fsl-edma: add i.mx7ulp edma2 version support
dt-bindings: dma: fsl-edma: add new i.mx7ulp-edma
dmaengine: fsl-edma-common: version check for v2 instead
dmaengine: fsl-edma-common: move dmamux register to another single function
dmaengine: fsl-edma: add drvdata for fsl-edma
dmaengine: Revert "dmaengine: fsl-edma: support little endian for edma driver"
dmaengine: rcar-dmac: Reject zero-length slave DMA requests
dmaengine: dw: Enable iDMA 32-bit on Intel Elkhart Lake
dmaengine: dw-edma: fix semicolon.cocci warnings
dmaengine: sh: usb-dmac: Use [] to denote a flexible array member
dmaengine: dmatest: timeout value of -1 should specify infinite wait
dmaengine: dw: Distinguish ->remove() between DW and iDMA 32-bit
dmaengine: fsl-edma: support little endian for edma driver
dmaengine: hsu: Revert "set HSU_CH_MTSR to memory width"
dmagengine: pl330: add code to get reset property
dt-bindings: pl330: document the optional resets property
...
Pull MTD updates from Miquel Raynal:
"This contains the following changes for MTD:
MTD core changes:
- New Hyperbus framework
- New _is_locked (concat) implementation
- Various cleanups
NAND core changes:
- use longest matching pattern in ->exec_op() default parser
- export NAND operation tracer
- add flag to indicate panic_write in MTD
- use kzalloc() instead of kmalloc() and memset()
Raw NAND controller drivers changes:
- brcmnand:
- fix BCH ECC layout for large page NAND parts
- fallback to detected ecc-strength, ecc-step-size
- when oops in progress use pio and interrupt polling
- code refactor code to introduce helper functions
- add support for v7.3 controller
- FSMC:
- use nand_op_trace for operation tracing
- GPMI:
- move all driver code into single file
- various cleanups (including dmaengine changes)
- use runtime PM to manage clocks
- implement exec_op
- MTK:
- correct low level time calculation of r/w cycle
- improve data sampling timing for read cycle
- add validity check for CE# pin setting
- fix wrongly assigned OOB buffer pointer issue
- re-license MTK NAND driver as Dual MIT/GPL
- STM32:
- manage the get_irq error case
- increase DMA completion timeouts
Raw NAND chips drivers changes:
- Macronix: add read-retry support
Onenand driver changes:
- add support for 8Gb datasize chips
- avoid fall-through warnings
SPI-NAND changes:
- define macros for page-read ops with three-byte addresses
- add support for two-byte device IDs and then for GigaDevice
GD5F1GQ4UFxxG
- add initial support for Paragon PN26G0xA
- handle the case where the last page read has bitflips
SPI-NOR core changes:
- add support for the mt25ql02g and w25q16jv flashes
- print error in case of jedec read id fails
- is25lp256: add post BFPT fix to correct the addr_width
SPI NOR controller drivers changes:
- intel-spi: Add support for Intel Elkhart Lake SPI serial flash
- smt32: remove the driver as the driver was replaced by spi-stm32-qspi.c
- cadence-quadspi: add reset control"
* tag 'mtd/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (60 commits)
mtd: concat: implement _is_locked mtd operation
mtd: concat: refactor concat_lock/concat_unlock
mtd: abi: do not use C++ style comments in uapi header
mtd: afs: remove unneeded NULL check
mtd: rawnand: stm32_fmc2: increase DMA completion timeouts
mtd: rawnand: Use kzalloc() instead of kmalloc() and memset()
mtd: hyperbus: Add driver for TI's HyperBus memory controller
mtd: spinand: read returns badly if the last page has bitflips
mtd: spinand: Add initial support for Paragon PN26G0xA
mtd: rawnand: mtk: Re-license MTK NAND driver as Dual MIT/GPL
mtd: rawnand: gpmi: remove double assignment to block_size
dt-bindings: mtd: brcmnand: Add brcmnand, brcmnand-v7.3 support
mtd: rawnand: brcmnand: Add support for v7.3 controller
mtd: rawnand: brcmnand: Refactored code to introduce helper functions
mtd: rawnand: brcmnand: When oops in progress use pio and interrupt polling
mtd: Add flag to indicate panic_write
mtd: rawnand: Add Macronix NAND read retry support
mtd: onenand: Avoid fall-through warnings
mtd: spinand: Add support for GigaDevice GD5F1GQ4UFxxG
mtd: spinand: Add support for two-byte device IDs
...
The gpmi driver performance suffers from NAND operations being split
in multiple small DMA transfers. This has been forced by the NAND layer
in the former days, but now with exec_op we can use the controller as
intended.
With this patch gpmi_nfc_exec_op becomes the main entry point to NAND
operations. Here all instructions are collected and chained as separate
DMA transfers. In the end whole chain is fired and waited to be
finished. gpmi_nfc_exec_op only does the hardware operations, bad block
marker swapping and buffer scrambling is done by the callers. It's worth
noting that the nand_*_op functions always take the buffer lengths for
the data that the NAND chip actually transfers. When doing BCH we have
to calculate the net data size from the raw data size in some places.
This patch has been tested with 2048/64 and 2048/128 byte NAND on
i.MX6q. mtd_oobtest, mtd_subpagetest and mtd_speedtest run without
errors. nandbiterrs, nandpagetest and nandsubpagetest userspace tests
from mtdutils run without errors and UBIFS can successfully be mounted.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
The mxs dma driver uses the flags parameter in dmaengine_prep_slave_sg() for
custom flags, but still uses the dmaengine specific names of the flags.
Do a little bit better and at least give the flag a custom name.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
The mxs dma driver can do PIO transfers. A pointer to the PIO words
to transfer is passed in the struct scatterlist * argument of
dmaengine_prep_slave_sg(). It's quite ugly and non obvious to cast
u32 * to struct scatterlist * each time when calling
dmaengine_prep_slave_sg(), so add a static inline wrapper function
to be called by the user along with a description what is going on.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Based on 1 normalized pattern(s):
this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 285 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this 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
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 14 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.915677517@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two drivers that are relying on the iDMA 64-bit driver name
to match. Instead of duplicating string in both of them, dedicate
a header file and share it between users.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This patch updates license to use SPDX-License-Identifier
instead of verbose license text.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Here is a kinda big refactoring that should have been done
in the first place, when Intel iDMA 32-bit support appeared.
It splits operations which are different to Synopsys DesignWare and
Intel iDMA 32-bit controllers.
No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"This includes a new driver, removes R-Mobile APE6 as it is no longer
used, sprd cyclic dma support, last batch of dma_slave_config
direction removal and random updates to bunch of drivers.
Summary:
- New driver for UniPhier MIO DMA controller
- Remove R-Mobile APE6 support
- Sprd driver updates and support for cyclic link-list
- Remove dma_slave_config direction usage from rest of drivers
- Minor updates to dmatest, dw-dmac, zynqmp and bcm dma drivers"
* tag 'dmaengine-4.21-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (48 commits)
dmaengine: qcom_hidma: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: pxa: remove DBGFS_FUNC_DECL()
dmaengine: mic_x100_dma: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: amba-pl08x: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: Documentation: Add documentation for multi chan testing
dmaengine: dmatest: Add transfer_size parameter
dmaengine: dmatest: Add alignment parameter
dmaengine: dmatest: Use fixed point div to calculate iops
dmaengine: dmatest: Add support for multi channel testing
dmaengine: rcar-dmac: Document R8A774C0 bindings
dt-bindings: dmaengine: usb-dmac: Add binding for r8a774c0
dmaengine: zynqmp_dma: replace spin_lock_bh with spin_lock_irqsave
dmaengine: sprd: Add me as one of the module authors
dmaengine: sprd: Support DMA 2-stage transfer mode
dmaengine: sprd: Support DMA link-list cyclic callback
dmaengine: sprd: Set cur_desc as NULL when free or terminate one dma channel
dmaengine: sprd: Fix the last link-list configuration
dmaengine: sprd: Get transfer residue depending on the transfer direction
dmaengine: sprd: Remove direction usage from struct dma_slave_config
dmaengine: dmatest: fix a small memory leak in dmatest_func()
...
The Spreadtrum DMA controller supports channel 2-stage tansfer mode,
that means we can request 2 dma channels, one for source channel, and
another one for destination channel. Once the source channel's transaction
is done, it will trigger the destination channel's transaction automatically
by hardware signal.
Signed-off-by: Eric Long <eric.long@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
As the pxa architecture and all its related drivers do not rely anymore
on the filter function, thanks to the slave map conversion, make
pxad_filter_fn() static, and remove it from the global namespace.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vkoul@kernel.org>
The Spreadtrum DMA can support the link-list transaction mode, which means
DMA controller can do transaction one by one automatically once we linked
these transaction by link-list register.
Signed-off-by: Eric Long <eric.long@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull DMAengine updates from Vinod Koul:
"This round brings couple of framework changes, a new driver and usual
driver updates:
- new managed helper for dmaengine framework registration
- split dmaengine pause capability to pause and resume and allow
drivers to report that individually
- update dma_request_chan_by_mask() to handle deferred probing
- move imx-sdma to use virt-dma
- new driver for Actions Semi Owl family S900 controller
- minor updates to intel, renesas, mv_xor, pl330 etc"
* tag 'dmaengine-4.19-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (46 commits)
dmaengine: Add Actions Semi Owl family S900 DMA driver
dt-bindings: dmaengine: Add binding for Actions Semi Owl SoCs
dmaengine: sh: rcar-dmac: Should not stop the DMAC by rcar_dmac_sync_tcr()
dmaengine: mic_x100_dma: use the new helper to simplify the code
dmaengine: add a new helper dmaenginem_async_device_register
dmaengine: imx-sdma: add memcpy interface
dmaengine: imx-sdma: add SDMA_BD_MAX_CNT to replace '0xffff'
dmaengine: dma_request_chan_by_mask() to handle deferred probing
dmaengine: pl330: fix irq race with terminate_all
dmaengine: Revert "dmaengine: mv_xor_v2: enable COMPILE_TEST"
dmaengine: mv_xor_v2: use {lower,upper}_32_bits to configure HW descriptor address
dmaengine: mv_xor_v2: enable COMPILE_TEST
dmaengine: mv_xor_v2: move unmap to before callback
dmaengine: mv_xor_v2: convert callback to helper function
dmaengine: mv_xor_v2: kill the tasklets upon exit
dmaengine: mv_xor_v2: explicitly freeup irq
dmaengine: sh: rcar-dmac: Add dma_pause operation
dmaengine: sh: rcar-dmac: add a new function to clear CHCR.DE with barrier
dmaengine: idma64: Support dmaengine_terminate_sync()
dmaengine: hsu: Support dmaengine_terminate_sync()
...
Vertical flip state is exported in xilinx_vdma_config and depending
on IP configuration(c_enable_vert_flip) vertical flip state is
programmed in hardware.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add some documentation for the pxad_param structure, and describe the
contract behind the minimal required priority of a DMA channel.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vkoul@kernel.org>
