The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230718143138.1066177-1-robh@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"New support:
- TI J721S2 CSI BCDMA support
Updates:
- Native HDMI support for dw edma driver
- ste dma40 updates for supporting proper SRAM handle in DT
- removal of dma device chancnt setting in drivers"
* tag 'dmaengine-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (28 commits)
dmaengine: sprd: Don't set chancnt
dmaengine: hidma: Don't set chancnt
dmaengine: plx_dma: Don't set chancnt
dmaengine: axi-dmac: Don't set chancnt
dmaengine: dw-axi-dmac: Don't set chancnt
dmaengine: qcom: bam_dma: allow omitting num-{channels,ees}
dmaengine: dw-edma: Add HDMA DebugFS support
dmaengine: dw-edma: Add support for native HDMA
dmaengine: dw-edma: Create a new dw_edma_core_ops structure to abstract controller operation
dmaengine: dw-edma: Rename dw_edma_core_ops structure to dw_edma_plat_ops
dmaengine: ste_dma40: use proper format string for resource_size_t
dmaengine: make QCOM_HIDMA depend on HAS_IOMEM
dmaengine: ste_dma40: fix typo in enum documentation
dmaengine: ste_dma40: use correct print specfier for resource_size_t
MAINTAINERS: Add myself as the DW eDMA driver reviewer
MAINTAINERS: Add Manivannan to DW eDMA driver maintainers list
MAINTAINERS: Demote Gustavo Pimentel to DW EDMA driver reviewer
dmaengine: ti: k3-udma: Add support for J721S2 CSI BCDMA instance
dt-bindings: dma: ti: Add J721S2 BCDMA
dmaengine: ti: k3-psil-j721s2: Add PSI-L thread map for main CPSW2G
...
We get a warning when PM is not set:
../drivers/dma/ti/k3-udma.c:5552:12: warning: 'udma_pm_resume' defined but not used [-Wunused-function]
5552 | static int udma_pm_resume(struct device *dev)
| ^~~~~~~~~~~~~~
../drivers/dma/ti/k3-udma.c:5530:12: warning: 'udma_pm_suspend' defined but not used [-Wunused-function]
5530 | static int udma_pm_suspend(struct device *dev)
| ^~~~~~~~~~~~~~~
Fix this by annotating pm function with __maybe_unused
Fixes: fbe05149e4 ("dmaengine: ti: k3-udma: Add system suspend/resume support")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20230516174311.117264-1-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Per [1], UDMA TR15 transactions may hang if ICNT0 is less than 64B
Work around is to set EOL flag is to 1 for ICNT0.
Since, there is no performance penalty / side effects of setting EOL
flag event ICNTO > 64B, just set the flag for all UDMAP TR15
descriptors.
[1] https://www.ti.com/lit/er/sprz455a/sprz455a.pdf
Errata doc for J721E DRA829/TDA4VM Processors Silicon Revision 1.1/1.0
(Rev. A)
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
[j-choudhary@ti.com: minor cleanups]
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Link: https://lore.kernel.org/r/20230323120107.27638-1-j-choudhary@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The K3 platforms configure the DMA resources with the
help of the TI's System Firmware's Device Manager(DM)
over TISCI. The group of DMA related Resource Manager[1]
TISCI messages includes: INTA, RINGACC, UDMAP, and PSI-L.
This configuration however, does not persist in the DM
after leaving from Suspend-to-RAM state. We have to restore
the DMA channel configuration over TISCI for all configured
channels when returning from suspend.
The TISCI resource management calls for each DMA type (UDMA,
PKTDMA, BCDMA) happen in device_free_chan_resources() and
device_alloc_chan_resources(). In pm_suspend() we store
the current udma_chan_config for channels that still have
attached clients and call device_free_chan_resources().
In pm_resume() restore the udma_channel_config from backup
and call device_alloc_chan_resources() for those channels.
Drivers like CPSW that use k3-udma-glue already do their own
DMA resource management so use the late system suspend/resume hooks.
[1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/index.html#resource-management-rm
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
[g-vlaev@ti.com: Add patch description and config backup]
[g-vlaev@ti.com: Supend only channels with clients]
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20230329155349.2566010-1-vigneshr@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"A new driver, couple of device support and binding conversion along
with bunch of driver updates are the main features of this.
New hardware support:
- TI AM62Ax controller support
- Xilinx xdma driver
- Qualcomm SM6125, SM8550, QDU1000/QRU1000 GPI controller
Updates:
- Runtime pm support for at_xdmac driver
- IMX sdma binding conversion to yaml and HDMI audio support
- IMX mxs binding conversion to yaml"
* tag 'dmaengine-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (35 commits)
dmaengine: idma64: Update bytes_transferred field
dmaengine: imx-sdma: Set DMA channel to be private
dmaengine: dw: Move check for paused channel to dwc_get_residue()
dmaengine: ptdma: check for null desc before calling pt_cmd_callback
dmaengine: dw-axi-dmac: Do not dereference NULL structure
dmaengine: idxd: Fix default allowed read buffers value in group
dmaengine: sf-pdma: pdma_desc memory leak fix
dmaengine: Simplify dmaenginem_async_device_register() function
dmaengine: use sysfs_emit() to instead of scnprintf()
dmaengine: Make an order in struct dma_device definition
dt-bindings: dma: cleanup examples - indentation, lowercase hex
dt-bindings: dma: drop unneeded quotes
dmaengine: xilinx: xdma: Add user logic interrupt support
dmaengine: xilinx: xdma: Add xilinx xdma driver
dmaengine: drivers: Use devm_platform_ioremap_resource()
dmaengine: at_xdmac: remove empty line
dmaengine: at_xdmac: add runtime pm support
dmaengine: at_xdmac: align properly function members
dmaengine: ppc4xx: Convert to use sysfs_emit()/sysfs_emit_at() APIs
dmaengine: sun6i: Set the maximum segment size
...
PSIL_EP_NATIVE endpoints may not have PEER registers for BCNT and thus
udma_decrement_byte_counters() should not try to decrement these counters.
This fixes the issue of crypto IPERF testing where the client side (EVM)
hangs without transfer of packets to the server side, seen since this
function was added.
Fixes: 7c94dcfa8f ("dmaengine: ti: k3-udma: Reset UDMA_CHAN_RT byte counters to prevent overflow")
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20221128085005.489964-1-j-choudhary@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Currently k3-udma driver is built as separate platform drivers with a
shared probe and identical code path, just differnet platform data.
To enable to build as module, convert the separate platform driver
into a single module_platform_driver with the data selection done via
compatible string and of_match. The separate of_match tables are also
combined into a single table to avoid the multiple calls to
of_match_node()
Since all modern TI platforms using this are DT enabled, the removal
of separate platform_drivers should have no functional change.
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20220929234820.940048-3-khilman@baylibre.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
If the DMA consumer driver does not expect the callback for TX done, then
we need not perform the channel RT byte counter calculations and estimate
the completion but return complete on first attempt itself.This assumes
that the consumer who did not request DMA_PREP_INTERRUPT has its own
mechanism for understanding TX completion, example: MCSPI EOW interrupt
can be used as TX completion signal for a SPI transaction.
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20220914110049.5842-1-vaishnav.a@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
UDMA_CHAN_RT_*BCNT_REG stores the real-time channel bytecount statistics.
These registers are 32-bit hardware counters and the driver uses these
counters to monitor the operational progress status for a channel, when
transferring more than 4GB of data it was observed that these counters
overflow and completion calculation of a operation gets affected and the
transfer hangs indefinitely.
This commit adds changes to decrease the byte count for every complete
transaction so that these registers never overflow and the proper byte
count statistics is maintained for ongoing transaction by the RT counters.
Earlier uc->bcnt used to maintain a count of the completed bytes at driver
side, since the RT counters maintain the statistics of current transaction
now, the maintenance of uc->bcnt is not necessary.
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20220802054835.19482-1-vaishnav.a@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"A bunch of new support and few updates to drivers:
New support:
- DMA_MEMCPY_SG support is bought back as we have a user in Xilinx
driver
- Support for TI J721S2 SoC in k3-udma driver
- Support for Ingenic MDMA and BDMA in the JZ4760
- Support for Renesas r8a779f0 dmac
Updates:
- We are finally getting rid of slave_id, so this brings in the
changes across tree for that
- updates for idxd driver
- at_xdmac driver cleanup"
* tag 'dmaengine-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (60 commits)
dt-bindings: dma-controller: Split interrupt fields in example
dmaengine: pch_dma: Remove usage of the deprecated "pci-dma-compat.h" API
dmaengine: at_xdmac: Fix race over irq_status
dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet()
dmaengine: at_xdmac: Fix at_xdmac_lld struct definition
dmaengine: at_xdmac: Fix lld view setting
dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_advance_work()
dmaengine: at_xdmac: Fix concurrency over xfers_list
dmaengine: at_xdmac: Move the free desc to the tail of the desc list
dmaengine: at_xdmac: Fix race for the tx desc callback
dmaengine: at_xdmac: Fix concurrency over chan's completed_cookie
dmaengine: at_xdmac: Print debug message after realeasing the lock
dmaengine: at_xdmac: Start transfer for cyclic channels in issue_pending
dmaengine: at_xdmac: Don't start transactions at tx_submit level
dmaengine: idxd: deprecate token sysfs attributes for read buffers
dmaengine: idxd: change bandwidth token to read buffers
dmaengine: idxd: fix wq settings post wq disable
dmaengine: idxd: change MSIX allocation based on per wq activation
dmaengine: idxd: fix descriptor flushing locking
dmaengine: idxd: embed irq_entry in idxd_wq struct
...
Pull MSI irq updates from Thomas Gleixner:
"Rework of the MSI interrupt infrastructure.
This is a treewide cleanup and consolidation of MSI interrupt handling
in preparation for further changes in this area which are necessary
to:
- address existing shortcomings in the VFIO area
- support the upcoming Interrupt Message Store functionality which
decouples the message store from the PCI config/MMIO space"
* tag 'irq-msi-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (94 commits)
genirq/msi: Populate sysfs entry only once
PCI/MSI: Unbreak pci_irq_get_affinity()
genirq/msi: Convert storage to xarray
genirq/msi: Simplify sysfs handling
genirq/msi: Add abuse prevention comment to msi header
genirq/msi: Mop up old interfaces
genirq/msi: Convert to new functions
genirq/msi: Make interrupt allocation less convoluted
platform-msi: Simplify platform device MSI code
platform-msi: Let core code handle MSI descriptors
bus: fsl-mc-msi: Simplify MSI descriptor handling
soc: ti: ti_sci_inta_msi: Remove ti_sci_inta_msi_domain_free_irqs()
soc: ti: ti_sci_inta_msi: Rework MSI descriptor allocation
NTB/msi: Convert to msi_on_each_desc()
PCI: hv: Rework MSI handling
powerpc/mpic_u3msi: Use msi_for_each-desc()
powerpc/fsl_msi: Use msi_for_each_desc()
powerpc/pasemi/msi: Convert to msi_on_each_dec()
powerpc/cell/axon_msi: Convert to msi_on_each_desc()
powerpc/4xx/hsta: Rework MSI handling
...
Smatch reports below warnings [1] wrt dereferencing rm_res when it can
potentially be ERR_PTR(). This is possible when entire range is
allocated to Linux
Fix this case by making sure, there is no deference of rm_res when its
ERR_PTR().
[1]:
drivers/dma/ti/k3-udma.c:4524 udma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4537 udma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4681 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4696 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4711 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4848 pktdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
drivers/dma/ti/k3-udma.c:4861 pktdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20211209180957.29036-1-vigneshr@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
udma_get_*() checks if rchan/tchan/rflow is already allocated by checking
if it has a NON NULL value. For the error cases, rchan/tchan/rflow will
have error value and udma_get_*() considers this as already allocated
(PASS) since the error values are NON NULL. This results in NULL pointer
dereference error while de-referencing rchan/tchan/rflow.
Reset the value of rchan/tchan/rflow to NULL if a channel request fails.
CC: stable@vger.kernel.org
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211031032411.27235-3-kishon@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
bcdma_get_*() checks if bchan is already allocated by checking if it
has a NON NULL value. For the error cases, bchan will have error value
and bcdma_get_*() considers this as already allocated (PASS) since the
error values are NON NULL. This results in NULL pointer dereference
error while de-referencing bchan.
Reset the value of bchan to NULL if a channel request fails.
CC: stable@vger.kernel.org
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211031032411.27235-2-kishon@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Fix the following fallthrough warning:
drivers/dma/ti/k3-udma.c:4951:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
The UDMA and BCDMA can provide higher throughput if the burst_size of the
channel is changed from it's default (which is 64 bytes) for Ultra-high
and high capacity channels.
This performance benefit is even more visible when the buffers are aligned
with the burst_size configuration.
The am654 does not have a way to change the burst size, but it is using
64 bytes burst, so increasing the copy_align from 8 bytes to 64 (and
clients taking that into account) can increase the throughput as well.
Numbers gathered on j721e:
echo 8000000 > /sys/module/dmatest/parameters/test_buf_size
echo 2000 > /sys/module/dmatest/parameters/timeout
echo 50 > /sys/module/dmatest/parameters/iterations
echo 1 > /sys/module/dmatest/parameters/max_channels
Prior this patch: ~1.3 GB/s
After this patch: ~1.8 GB/s
with 1 byte alignment: ~1.7 GB/s
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20210113114923.9231-3-peter.ujfalusi@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
BCDMA RX channels have one flow per channel, therefore set the rflow_cnt
to rchan_cnt.
Without this patch, request for BCDMA RX channel allocation fails as
rflow_cnt is 0 thus fails to reserve a rflow for the channel.
Fixes: 8844898028 ("dmaengine: ti: k3-udma: Add support for BCDMA channel TPL handling")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210112141403.30286-1-vigneshr@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
One of the DMAs introduced with AM64 is the Packet DMA (PKTDMA).
It serves similar purpose as K3 UDMAP channels in packet mode, but with
notable differences, like tflow support and channels being allocated to
service specific peripherals.
The rings for the PKTDMA is integrated within the DMA itself instead of
using rings from the general purpose ringacc.
PKTDMA can be used to service PSI-L peripherals, similarly to
K3 UDMA channels.
Most of the driver code can be reused for PKTDMA tchan/rchan support but
new setup and allocation functions are needed to handle the differences
between the DMAs.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20201208090440.31792-20-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Unlike UDMAP the BCDMA defines the channel TPL levels per channel type.
In UDMAP the number of high and ultra-high channels applies to both tchan
and rchan.
BCDMA defines the TPL per channel types: bchan, tchan and rchan can have
different number of high and ultra-high channels.
In order to support BCDMA channel TPL we need to move the tpl information
as per channel type property for the DMAs.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20201208090440.31792-19-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
One of the DMAs introduced with AM64 is the Block Copy DMA (BCDMA).
It serves similar purpose as K3 UDMAP channels in TR mode.
The rings for the BCDMA is integrated within the DMA itself instead of
using rings from the general purpose ringacc.
A BCDMA have two different type of channels:
- Block Copy Channels (bchan)
- Split Channels (tchan and rchan)
tchan and rchan can be used to service PSI-L peripherals, similarly to
K3 UDMA channels.
bchan can be only used for block copy operation (TR type15) like the
paired K3 UDMA tchan/rchan configured in block copy mode.
bchans can be also used to service peripherals directly if an external
trigger is selected for the channel.
Most of the driver code can be reused for BCDMA bchan/tchan/rchan support
but new setup and allocation functions are needed to handle the
differences between the DMAs.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20201208090440.31792-18-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Use separate data for SoC dependent parameters. These parameters depends
on the DMA integration (either in HW or in SYSFW), the DMA controller
itself remains compatible with either the am654 or j721e variant.
j7200 have the same DMA as j721e with different number of channels, which
can be queried from HW, but SYSFW defines different rchan_oes_offset
number for j7200 (0x80) compared to j721e (0x400).
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200910124329.21206-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The TR which needs to be initialized for the next sg entry is indexed by
tr_idx and not by the running i counter.
In case any sub element in the SG needs more than one TR, the code would
corrupt an already configured TR.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200824120108.9178-1-peter.ujfalusi@ti.com
Fixes: 6cf668a4ef ("dmaengine: ti: k3-udma: Use the TR counter helper for slave_sg and cyclic")
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"Core:
- Support out of order dma completion
- Support for repeating transaction
New controllers:
- Support for Actions S700 DMA engine
- Renesas R8A774E1, r8a7742 controller binding
- New driver for Xilinx DPDMA controller
Other:
- Support of out of order dma completion in idxd driver
- W=1 warning cleanup of subsystem
- Updates to ti-k3-dma, dw, idxd drivers"
* tag 'dmaengine-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (68 commits)
dmaengine: dw: Don't include unneeded header to platform data header
dmaengine: Actions: Add support for S700 DMA engine
dmaengine: Actions: get rid of bit fields from dma descriptor
dt-bindings: dmaengine: convert Actions Semi Owl SoCs bindings to yaml
dmaengine: idxd: add missing invalid flags field to completion
dmaengine: dw: Initialize max_sg_burst capability
dmaengine: dw: Introduce max burst length hw config
dmaengine: dw: Initialize min and max burst DMA device capability
dmaengine: dw: Set DMA device max segment size parameter
dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config
dmaengine: Introduce DMA-device device_caps callback
dmaengine: Introduce max SG burst capability
dmaengine: Introduce min burst length capability
dt-bindings: dma: dw: Add max burst transaction length property
dt-bindings: dma: dw: Convert DW DMAC to DT binding
dmaengine: ti: k3-udma: Query throughput level information from hardware
dmaengine: ti: k3-udma: Use defines for capabilities register parsing
dmaengine: xilinx: dpdma: Fix kerneldoc warning
dmaengine: xilinx: dpdma: add missing kernel doc
dmaengine: xilinx: dpdma: remove comparison of unsigned expression
...
