sg->length may or may not contain the length of the dma region to transfer,
depending on the architecture - dma_sg_len(sg) always will though. For the
architectures which use the drivers modified by this patch it probably is the
case that sg->length contains the dma transfer length. But to be consistent and
future proof change them to use dma_sg_len.
To quote Russel King:
sg->length is meaningless to something performing DMA.
In cases where sg_dma_len(sg) and sg->length are the same storage, then
there's no problem. But scatterlists _can_ (and one some architectures) do
split them - especially when you have an IOMMU which can allow you to
combine a scatterlist into fewer entries.
So, anything using sg->length for the size of a scatterlist's DMA transfer
_after_ a call to dma_map_sg() is almost certainly buggy.
The patch has been generated using the following coccinelle patch:
<smpl>
@@
struct scatterlist *sg;
expression X;
@@
-sg[X].length
+sg_dma_len(&sg[X])
@@
struct scatterlist *sg;
@@
-sg->length
+sg_dma_len(sg)
</smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
The current code keeps the callbacks invoked from interrupt context, this
does not conform to the Documentation/dmaengine.txt.
So add tasklet support to fix this issue.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
the current i.MX clock support groups together unrelated clocks
to a single clock which is then used by the driver. This can't
be accomplished with the generic clock framework so we instead
request the individual clocks in the driver. For i.MX there are
generally three different clocks:
ipg: bus clock (needed to access registers)
ahb: dma relevant clock, sometimes referred to as hclk in the datasheet
per: bit clock, pixel clock
This patch changes the driver to request the individual clocks.
Currently all clk_get will get the same clock until the SoCs
are converted to the generic clock framework
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Pull slave-dmaengine update from Vinod Koul:
"This includes the cookie cleanup by Russell, the addition of context
parameter for dmaengine APIs, more arm dmaengine driver cleanup by
moving code to dmaengine, this time for imx by Javier and pl330 by
Boojin along with the usual driver fixes."
Fix up some fairly trivial conflicts with various other cleanups.
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (67 commits)
dmaengine: imx: fix the build failure on x86_64
dmaengine: i.MX: Fix merge of cookie branch.
dmaengine: i.MX: Add support for interleaved transfers.
dmaengine: imx-dma: use 'dev_dbg' and 'dev_warn' for messages.
dmaengine: imx-dma: remove 'imx_dmav1_baseaddr' and 'dma_clk'.
dmaengine: imx-dma: remove unused arg of imxdma_sg_next.
dmaengine: imx-dma: remove internal structure.
dmaengine: imx-dma: remove 'resbytes' field of 'internal' structure.
dmaengine: imx-dma: remove 'in_use' field of 'internal' structure.
dmaengine: imx-dma: remove sg member from internal structure.
dmaengine: imx-dma: remove 'imxdma_setup_sg_hw' function.
dmaengine: imx-dma: remove 'imxdma_config_channel_hw' function.
dmaengine: imx-dma: remove 'imxdma_setup_mem2mem_hw' function.
dmaengine: imx-dma: remove dma_mode member of internal structure.
dmaengine: imx-dma: remove data member from internal structure.
dmaengine: imx-dma: merge old dma-v1.c with imx-dma.c
dmaengine: at_hdmac: add slave config operation
dmaengine: add context parameter to prep_slave_sg and prep_dma_cyclic
dmaengine/dma_slave: introduce inline wrappers
dma: imx-sdma: Treat firmware messages as warnings instead of erros
...
Add context parameter to device_prep_slave_sg() and device_prep_dma_cyclic()
interfaces to allow passing client/target specific information associated
with the data transfer.
Modify all affected DMA engine drivers.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
As the SDMA controller can operate without an external firmware being loaded,
treat the firmware related messages as warnings rather than errors.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Ensure all DMA engine drivers initialize their cookies in the same way,
so that they all behave in a similar fashion. This means their first
issued cookie will be 2 rather than 1, and will increment to INT_MAX
before returning 1 and starting over.
In connection with this, Dan Williams said:
> Russell King wrote:
> > Secondly, some DMA engine drivers initialize the dma_chan cookie to 0,
> > others to 1. Is there a reason for this, or are these all buggy?
>
> I know that ioat and iop-adma expect 0 to mean "I have cleaned up this
> descriptor and it is idle", and would break if zero was an in-flight
> cookie value. The reserved usage of zero is an driver internal
> concern, but I have no problem formalizing it as a reserved value.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Provide a common function to do the cookie mechanics for completing
a DMA descriptor.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Everyone deals with assigning DMA cookies in the same way (it's part of
the API so they should be), so lets consolidate the common code into a
helper function to avoid this duplication.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Add a local private header file to contain definitions and declarations
which should only be used by DMA engine drivers.
We also fix linux/dmaengine.h to use LINUX_DMAENGINE_H to guard against
multiple inclusion.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Every DMA engine implementation declares a last completed dma cookie
in their private dma channel structures. This is pointless, and
forces driver specific code. Move this out into the common dma_chan
structure.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
This reverts commit 865d9438eb.
The module.h incsuion twice has been updated tree wide hence this is not
required to be merged.
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Print a message when firmare fails to be requested in the case of platform data being used.
While at it, distinguish between the error messages of the device tree and platform data cases.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
On the device tree case the code bails out when the firmware name cannot be found
or if the firmware fails to be requested.
Fix this behaviour as the SDMA engine can still operate with the built-in
ROM scripts.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
drivers/dma/imx-dma.c and drivers/dma/imx-sdma.c included
'linux/module.h' twice, remove the duplicates.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Different tree maintainers picked up independently generated
trivial compile fixes based on linux-next testing, resulting
in some cases where a file would have got more than one addition
of module.h once everything was all merged together.
Delete any duplicates so includecheck isn't complaining about
anything related to module.h/export.h changes.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Commit 6584cb88 (ARM i.MX dma: Fix burstsize settings) fixed
the mxcmmc driver but forgot to fix the SDMA driver to handle the
correct burtsize.
This make the SD card access works again with DMA on i.MX31 boards.
Signed-off-by: Philippe Rétornaz <philippe.retornaz@epfl.ch>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Commit 6584cb88 (ARM i.MX dma: Fix burstsize settings) fixed
the mxcmmc driver but forgot to fix the SDMA driver to handle the
correct burtsize.
This make the SD card access works again with DMA on i.MX31 boards.
Signed-off-by: Philippe Rétornaz <philippe.retornaz@epfl.ch>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
We don't need extra lock, so we use non-atomic bit ops to set/clear bits,
merge event_mask0 and event_mask1 into an array, it helps use bit ops.
It also fixs the issue:
sdmac->event_mask0 = 1 << sdmac->event_id0;
sdmac->event_mask1 = 1 << (sdmac->event_id0 - 32);
It event_id0 < 32, it shifts negative number. If event_id0 >= 32, it
shifts number >= sizeof(int). Both the cases behavior is undefined.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
event number is not always 32. use num_events for checking instead.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
It makes clk_enable/disable pair more readable, and fix one bug:
sdma_init calls sdma_request_channel, but seems don't know
sdma_request_channel enabled the clock.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
[fixed typo in commit log]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
sdma_request_channel sets the default priority. sdma_alloc_chan_resources
should call sdma_set_channel_priority thereafter to over write it.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
use readl_relaxed/writel_relaxed in most places, and use writel when
enable channel, because it needs memory barrier.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
The DMA engine API requires that transfers are started in issue_pending
instead of tx_submit. Fix this.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[corrected change log to DMA engine API insteadof DMA API]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
mx53_loco: fix deadlock report from sdma_tx_submit() during boot
BugLink: http://bugs.launchpad.net/bugs/878701
Adjust to use spin_lock_irqsave()/spin_unlock_irqresotre(), so to
make it safe when called from interrupt context.
Signed-off-by: Haitao Zhang <haitao.zhang@linaro.org>
Signed-off-by: Eric Miao <eric.miao@linaro.org>
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
When we use the SDMA in the UART driver(such as imx6q), we will
meet one situation:
Assume we set 64 bytes for the RX DMA buffer.
The RX DMA buffer has received some data, but not full.
An Aging DMA request will be received by the SDMA controller if we enable the
IDDMAEN(UCR4[6]) in this case.
So the UART driver needs to know the count of the real received bytes,
and push them to upper layer.
Add two new fields to sdmac, and update the `residue` in sdma_tx_status().
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Set the right DMA direction in the sdma_control(), else
we will get the wrong log when enable the DYNAMIC_DEBUG.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
Fix files that were implicitly using module.h but not
calling it out for inclusion directly. We'll break those
once we remove the implicit presence otherwise
[With input from Uwe Kleine-König <u.kleine-koenig@pengutronix.de>]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Add missing include of linux/module.h to fix build error.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The firmware blob may not be available when the driver
probes. Instead of blocking the whole kernel use
request_firmware_nowait() and continue without firmware.
The ROM scripts can already be used then if available.
For the devicetree case the ROM scripts are not available,
still the probe function should not block. The driver
will be unusable in this case, but we have no way of
detecting this properly. The configuration of the dma
channels will fail, so nothing bad should happen.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
If we do not have a firmare script for a given transfer,
the setup of this channel must fail. For this the script
addresses have to be < 0 initially, not 0.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
channel0 of the sdma engine is the configuration channel. It
is a shared resource and thus must be protected by a mutex.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
It does not need to allocate space and copy fw_name in function
sdma_get_firmware().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
It might be not good to use software defined version to identify sdma
device type, when hardware does not define such version. Instead,
soc name is stable enough to define the device type.
The patch uses platform_device_id rather than version number passed
by platform data to identify sdma device type/version.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Vinod Koul <vinod.koul@intel.com>
It is not good to have cpu_name and to_version encoded into sdma
firmware name as variables. For example, there are three TOs of
imx51 soc, the sdma script never changes since TO1, which means
all three TOs of imx51 uses TO1 version of sdma script. But we
have to prepare three identical firmwares, sdma-imx51-to1.bin
sdma-imx51-to2.bin and sdma-imx51-to3.bin, to have the kernel
capable of running on all three TOs.
The patch removes cpu_name and to_version from sdma platform data,
and instead uses fw_name to pass the firmware name, so that we can
pass the TO version where it's relevant and skip it where only one
firmware exists.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
As per the reference manual, bit "L" should be set while bit "C"
should be cleared for the last buffer descriptor in the non-cyclic
chain, so that sdma can stop trying to find the next BD and end
the transfer.
In case of sdma_prep_slave_sg(), BD_LAST needs to be set and BD_CONT
be cleared for the last BD.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
sdma_handle_channel_loop() is the handler of cyclic tx. One period
success does not really mean the success of the tx. Instead of
DMA_SUCCESS, DMA_IN_PROGRESS should be the one to tell.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The sdmac->status was designed to reflect the status of the tx,
so simply return it in sdma_tx_status(). Then dma client can call
dma_async_is_tx_complete() to know the status of the tx.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
sdma_prep_dma_cyclic() sets sdmac->status to DMA_ERROR in err_out,
and sdma_prep_slave_sg() needs to do the same. Otherwise,
sdmac->status stays at DMA_IN_PROGRESS, which will make the function
return immediately next time it gets called.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This is a leftover from the time that the driver did not have
sdma_prep_dma_cyclic callback and implemented sound dma as a looped
sg chain. And it can be removed now.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We need channel 0 of the sdma engine for internal purposes. We
accomplished this by calling dma_request_channel() in the probe
function. This does not work when multiple dma engines are
present which is the case when IPU support for i.MX31/35 is
compiled in. So instead of registering channel 0 and reserving
it afterwards simply do not register it in the first place.
With this the dmaengine channel counting does not match sdma
channel counting anymore, so we have to use sdma channel counting
in the driver.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch lets sdma_prep_slave_sg fail if the entries of an
sg list do not start on multiples of the word size or if the
lengths are not multiple of the word size.
Also, catch the previously unhandled DMA_SLAVE_BUSWIDTH_8_BYTES
and DMA_SLAVE_BUSWIDTH_UNDEFINED cases.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Variable name sdma and sdmac are consistently used as the pointer to
sdma_engine and sdma_channel respectively throughout the file. The
patch fixes the inconsistency seen in function sdma_assign_cookie().
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
When loading the microcode to the SDMA engine we have to use
the ram_code_start_addr found in the firmware image. The copy
in the sdma engine is not initialized correctly. This is broken
since:
5b28aa3 dmaengine i.MX SDMA: Allow to run without firmware
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The firmware framework gets initialized during fs_initcall time, so
we are not allowed to call request_firmware earlier.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently while submitting scatterlists with more than one SG
entry the DMA buffer address from the first SG entry is inserted
into all initialized DMA buffer descriptors. This is due to the
typo in the for_each_sg() loop where the scatterlist pointer is
used for obtaining the DMA buffer address and _not_ the SG list
iterator.
As a result all received data will be written only into the first
DMA buffer while reading. While writing the data from the first
DMA buffer is send to the device multiple times. This caused
the filesystem destruction on the MMC card when using DMA in
mxcmmc driver.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The SDMA firmware consists of a ROM part and a RAM part.
The ROM part is always present in the SDMA engine and
is sufficient for many cases.
This patch allows to pass in platform data containing
the script addresses in ROM, so loading a firmware is
optional now.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
This patch adds support for the Freescale i.MX SDMA engine.
The SDMA engine is a scatter/gather DMA engine which is implemented
as a seperate coprocessor. SDMA needs its own firmware which is
requested using the standard request_firmware mechanism. The firmware
has different entry points for each peripheral type, so drivers
have to pass the peripheral type to the DMA engine which in turn
picks the correct firmware entry point from a table contained in
the firmware image itself.
The original Freescale code also supports support for transfering
data to the internal SRAM which needs different entry points to
the firmware. Support for this is currently not implemented. Also,
support for the ASRC (asymmetric sample rate converter) is skipped.
I took a very simple approach to implement dmaengine support. Only
a single descriptor is statically assigned to a each channel. This
means that transfers can't be queued up but only a single transfer
is in progress. This simplifies implementation a lot and is sufficient
for the usual device/memory transfers.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Linus Walleij <linus.ml.walleij@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
