mxs dma channel hardware reset command is not reliable and can cause
a channel stall. The only way to fix the channel stall is a DMA engine
reset.
To avoid channel resets we use the hardware semaphore counter. For each
transmitted segment, the DMA channel will decrease the counter by one.
To use this mechanism with cyclic DMA, we need to increase the semaphore
counter with each completed DMA command in the interrupt handler. To
avoid any interruptions between the DMA transfers, the semaphore counter
is initialized with 2. This way the counter can be increased in the
interrupt handler without an influence on the transfer of the DMA
engine.
When disabling the channel, we stop increasing the semaphore counter in
the interrupt handler.
This patch was tested on i.MX28 with the SAIF DMA channel.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
After a channel reset, the channel stops running automatically. The
state update was missing so that a channel perperation right after a
channel reset failed.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This is no official errata, but I noticed that the channel reset may
stop working if the DMA state engine is in the READ_FLUSH state.
This patch uses the channel debug1 register to wait for the DMA
statemachine to leave the READ_FLUSH state. After that we can continue
to reset the channel.
Tested on i.MX28.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Use the channel's buffer address register to calculate correct residue
value for tx_status.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The DMA interrupt handler uses its controll registers to handle all
available channel interrupts it can find.
This patch changes it to handle only one interrupt by directly mapping
irq number to channel. It also includes a cleanup of the ctrl-register
usage.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
With all mxs-dma clients moved to use generic DMA helper, the code
left from generic DMA binding conversion can be removed now.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
last_used variable is applied only once, so, let's substitute it by its value.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Fix the following sparse warning:
drivers/dma/mxs-dma.c:696:17: warning: symbol 'mxs_dma_xlate' was not declared. Should it be static?
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Update mxs-dma driver to adopt generic DMA device tree binding. It
calls of_dma_controller_register() with mxs specific of_dma_xlate to
get the generic DMA device tree helper support. Then DMA clients only
need to call dma_request_slave_channel() for requesting a DMA channel
from dmaengine.
The existing way of requesting channel, clients directly call
dma_request_channel(), still work there, and will be removed after
all mxs-dma clients get converted to generic DMA device tree helper.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Fix the following warnings when building with W=1 option:
drivers/dma/mxs-dma.c: In function 'mxs_dma_alloc_chan_resources':
drivers/dma/mxs-dma.c:368:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/dma/mxs-dma.c: In function 'mxs_dma_prep_slave_sg':
drivers/dma/mxs-dma.c:481:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/dma/mxs-dma.c:494:3: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/dma/mxs-dma.c:515:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/dma/mxs-dma.c: In function 'mxs_dma_prep_dma_cyclic':
drivers/dma/mxs-dma.c:563:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Pull slave-dmaengine updates from Vinod Koul:
"This time we have Andy updates on dw_dmac which is attempting to make
this IP block available as PCI and platform device though not fully
complete this time.
We also have TI EDMA moving the dma driver to use dmaengine APIs, also
have a new driver for mmp-tdma, along with bunch of small updates.
Now for your excitement the merge is little unusual here, while
merging the auto merge on linux-next picks wrong choice for pl330
(drivers/dma/pl330.c) and this causes build failure. The correct
resolution is in linux-next. (DMA: PL330: Fix build error) I didn't
back merge your tree this time as you are better than me so no point
in doing that for me :)"
Fixed the pl330 conflict as in linux-next, along with trivial header
file conflicts due to changed includes.
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (29 commits)
dma: tegra: fix interrupt name issue with apb dma.
dw_dmac: fix a regression in dwc_prep_dma_memcpy
dw_dmac: introduce software emulation of LLP transfers
dw_dmac: autoconfigure data_width or get it via platform data
dw_dmac: autoconfigure block_size or use platform data
dw_dmac: get number of channels from hardware if possible
dw_dmac: fill optional encoded parameters in register structure
dw_dmac: mark dwc_dump_chan_regs as inline
DMA: PL330: return ENOMEM instead of 0 from pl330_alloc_chan_resources
DMA: PL330: Remove redundant runtime_suspend/resume functions
DMA: PL330: Remove controller clock enable/disable
dmaengine: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
DMA: PL330: Set the capability of pdm0 and pdm1 as DMA_PRIVATE
ARM: EXYNOS: Set the capability of pdm0 and pdm1 as DMA_PRIVATE
dma: tegra: use list_move_tail instead of list_del/list_add_tail
mxs/dma: Enlarge the CCW descriptor area to 4 pages
dw_dmac: utilize slave_id to pass request line
dmaengine: mmp_tdma: add dt support
dmaengine: mmp-pdma support
spi: davici - make davinci select edma
...
Change the parameter list of device_prep_dma_cyclic() so the DMA drivers
can receive the flags coming from clients.
This feature can be used during audio operation to disable all audio
related interrupts when the DMA_PREP_INTERRUPT is cleared from the flags.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
In case of a large SPI flash, the amount of DMA descriptors
available to the DMA driver is not large enough anymore. For
example 8MB SPI flash now needs 129 descriptors to be transfered
in one long read. There are currently 53 descriptors available in
one PAGE_SIZE-big block. Enlarge the allocated descriptor area to
four PAGE_SIZE blocks to fulfill such requirements.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Dan Williams <djbw@fb.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
mxs-dma.c provides two functions mxs_dma_is_apbh and mxs_dma_is_apbx
which are used at least in mxs-mmc.c. Building mxs-mmc as module
fails due to those two symbols not being exported.
Signed-off-by: Attila Kinali <attila@kinali.ch>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
These continue the device tree work from part 1, this set is for the
tegra, mxs and imx platforms, all of which have dependencies on clock
or pinctrl changes submitted earlier.
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Merge tag 'dt2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc device tree conversions (part 2) from Olof Johansson:
"These continue the device tree work from part 1, this set is for the
tegra, mxs and imx platforms, all of which have dependencies on clock
or pinctrl changes submitted earlier."
Fix up trivial conflicts due to nearby changes in
drivers/{gpio/gpio,i2c/busses/i2c}-mxs.c
* tag 'dt2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (73 commits)
ARM: dt: tegra: invert status=disable vs status=okay
ARM: dt: tegra: consistent basic property ordering
ARM: dt: tegra: sort nodes based on bus order
ARM: dt: tegra: remove duplicate device_type property
ARM: dt: tegra: consistenly use lower-case for hex constants
ARM: dt: tegra: format regs properties consistently
ARM: dt: tegra: gpio comment cleanup
ARM: dt: tegra: remove unnecessary unit addresses
ARM: dt: tegra: whitespace cleanup
ARM: dt: tegra cardhu: fix typo in SDHCI node name
ARM: dt: tegra: cardhu: register core regulator tps62361
ARM: dt: tegra30.dtsi: Add SMMU node
ARM: dt: tegra20.dtsi: Add GART node
ARM: dt: tegra30.dtsi: Add Memory Controller(MC) nodes
ARM: dt: tegra20.dtsi: Add Memory Controller(MC) nodes
ARM: dt: tegra: Add device tree support for AHB
ARM: dts: enable audio support for imx28-evk
ARM: dts: enable i2c device for imx28-evk
i2c: mxs: add device tree probe support
ARM: dts: enable mmc for imx28-evk
...
Rewrite mxs_dma_is_apbh and mxs_dma_is_apbx in order to support
other SoCs like imx6q and reform the platform_device_id for the
better further dt support.
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
This can get rid of the mach-dependency.
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
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>
Enable channel in device_issue_pending call, so that the order between
cookie assignment and channel enabling can be ensured naturally.
It fixes the mxs gpmi-nand breakage which is caused by the incorrect
order of cookie assigning and channel enabling.
Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Huang Shijie <b32955@freescale.com>
Tested-by <samgandhi9@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Artem's cleanup of the MTD API continues apace.
Fixes and improvements for ST FSMC and SuperH FLCTL NAND, amongst others.
More work on DiskOnChip G3, new driver for DiskOnChip G4.
Clean up debug/warning printks in JFFS2 to use pr_<level>.
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Merge tag 'for-linus-3.4' of git://git.infradead.org/mtd-2.6
Pull MTD changes from David Woodhouse:
- Artem's cleanup of the MTD API continues apace.
- Fixes and improvements for ST FSMC and SuperH FLCTL NAND, amongst
others.
- More work on DiskOnChip G3, new driver for DiskOnChip G4.
- Clean up debug/warning printks in JFFS2 to use pr_<level>.
Fix up various trivial conflicts, largely due to changes in calling
conventions for things like dmaengine_prep_slave_sg() (new inline
wrapper to hide new parameter, clashing with rewrite of previously last
parameter that used to be an 'append' flag, and is now a bitmap of
'unsigned long flags').
(Also some header file fallout - like so many merges this merge window -
and silly conflicts with sparse fixes)
* tag 'for-linus-3.4' of git://git.infradead.org/mtd-2.6: (120 commits)
mtd: docg3 add protection against concurrency
mtd: docg3 refactor cascade floors structure
mtd: docg3 increase write/erase timeout
mtd: docg3 fix inbound calculations
mtd: nand: gpmi: fix function annotations
mtd: phram: fix section mismatch for phram_setup
mtd: unify initialization of erase_info->fail_addr
mtd: support ONFI multi lun NAND
mtd: sm_ftl: fix typo in major number.
mtd: add device-tree support to spear_smi
mtd: spear_smi: Remove default partition information from driver
mtd: Add device-tree support to fsmc_nand
mtd: fix section mismatch for doc_probe_device
mtd: nand/fsmc: Remove sparse warnings and errors
mtd: nand/fsmc: Add DMA support
mtd: nand/fsmc: Access the NAND device word by word whenever possible
mtd: nand/fsmc: Use dev_err to report error scenario
mtd: nand/fsmc: Use devm routines
mtd: nand/fsmc: Modify fsmc driver to accept nand timing parameters via platform
mtd: fsmc_nand: add pm callbacks to support hibernation
...
[1] Background :
The GPMI does ECC read page operation with a DMA chain consist of three DMA
Command Structures. The middle one of the chain is used to enable the BCH,
and read out the NAND page.
The WAIT4END(wait for command end) is a comunication signal between
the GPMI and MXS-DMA.
[2] The current DMA code sets the WAIT4END bit at the last one, such as:
+-----+ +-----+ +-----+
| cmd | ------------> | cmd | ------------------> | cmd |
+-----+ +-----+ +-----+
^
|
|
set WAIT4END here
This chain works fine in the mx23/mx28.
[3] But in the new GPMI version (used in MX50/MX60), the WAIT4END bit should
be set not only at the last DMA Command Structure,
but also at the middle one, such as:
+-----+ +-----+ +-----+
| cmd | ------------> | cmd | ------------------> | cmd |
+-----+ +-----+ +-----+
^ ^
| |
| |
set WAIT4END here too set WAIT4END here
If we do not set WAIT4END, the BCH maybe stalls in "ECC reading page" state.
In the next ECC write page operation, a DMA-timeout occurs.
This has been catched in the MX6Q board.
[4] In order to fix the bug, rewrite the last parameter of mxs_dma_prep_slave_sg(),
and use the dma_ctrl_flags:
---------------------------------------------------------
DMA_PREP_INTERRUPT : append a new DMA Command Structrue.
DMA_CTRL_ACK : set the WAIT4END bit for this DMA Command Structure.
---------------------------------------------------------
[5] changes to the relative drivers:
<1> For mxs-mmc driver, just use the new flags, do not change any logic.
<2> For gpmi-nand driver, and use the new flags to set the DMA
chain, especially for ecc read page.
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Move the header to a more common place.
The mxs dma engine is not only used in mx23/mx28, but also used
in mx50/mx6q. It will also be used in the future chips.
Rename it to mxs-dma.h, and create a new folder include/linux/fsl/ to
store the Freescale's header files.
change mxs-dma driver, mxs-mmc driver, gpmi-nand driver, mxs-saif driver
to the new header file.
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Acked-by: Chris Ball <cjb@laptop.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
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>
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>
The patch converts mxs-dma driver to clk_prepare/clk_unprepare by
using helper functions clk_prepare_enable/clk_disable_unprepare.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Before dma_transfer_direction was introduced to replace
dma_data_direction, some dmaengine device uses DMA_NONE of
dma_data_direction for some talk with its client drivers.
The mxs-dma and its clients mxs-mmc and gpmi-nand are such case.
This patch adds DMA_TRANS_NONE to dma_transfer_direction and
migrate the DMA_NONE use in mxs-dma to it.
It also fixes the compile warning below.
CC drivers/dma/mxs-dma.o
drivers/dma/mxs-dma.c: In function ‘mxs_dma_prep_slave_sg’:
drivers/dma/mxs-dma.c:420:16: warning: comparison between ‘enum dma_transfer_direction’ and ‘enum dma_data_direction’
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
This is how the original Freescale code (unintentionally) worked,
because the code path which would have asserted the CLKGATE bit was
never actually reached in their code.
This fixes the nefarious "DMA timout" bug when multiple DMA channels
(e.g. GPMI NAND and MMC) are used at the same time.
If a better fix for this problem should be found, the clkgate handling
could be reinstated.
See http://lists.infradead.org/pipermail/linux-arm-kernel/2011-September/065228.html
Also reverse the order of mxs_dma_disable_chan() and
mxs_dma_reset_chan() in mxs_dma_control() because mxs_dma_reset_chan()
can only work when the DMA channel is enabled.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Using a static variable for counting the number of CCWs attached to
a DMA channel when appending a new descriptor is not multi user safe.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
There is no need to have the clock enabled all the time the driver is
loaded.
It will be enabled anyway in mxs_dma_alloc_chan_resources() when a
channel is actually going to be used.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
After calling mxs_dma_disable_chan() for a channel, that channel
becomes unusable because some controller registers can only be written
when the clock is enabled via CLKGATE.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
We met some channels in abnormal state after disable.
Reset it to get a clean state.
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
In general, the mxs-dma users get separate irq for each channel,
but gpmi is special one which has only one irq shared by all gpmi
channels. It causes mxs_dma channel allocation function fail for
all other gpmi channels except the first one calling into the
function.
The patch gets request_irq call skipped for NO_IRQ case, and leaves
this gpmi specific quirk to gpmi driver to sort out. It will fix
above problem if gpmi driver sets chan_irq as gpmi irq for only one
channel and NO_IRQ for all the rest channels.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.
* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
instances.
* apbh-dma is different between mx23 and mx28, hardware version
register is used to differentiate.
* mxs-dma supports pio function besides data transfer. The driver
uses dma_data_direction DMA_NONE to identify the pio mode, and
steals sgl and sg_len to get pio words and numbers from clients.
* mxs dmaengine has some very specific features, like sense function
and the special NAND support (nand_lock, nand_wait4ready). These
are too specific to implemented in generic dmaengine driver.
* The driver refers to imx-sdma and only a single descriptor is
statically assigned to each channel.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
