Once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory, otherwise we will
leak a reference to master. Fix by removing the unnecessary
spi_master_get() call.
Fixes: 33e195acf2 ('spi: mxs: use devm_spi_register_master()')
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.
[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's consistent with all the other spi drivers that way.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
mxs_spi_setup_transfer() would set the SSP SCK rate every time it was
called, which is before every transfer. It is uncommon for the SCK rate to
change between transfers (or at all of that matter) and this causes many
unnecessary reprogrammings of the clock registers.
Code changed to only set the rate when it changes. This significantly
speeds up short SPI messages, especially messages made up of many transfers,
as the calculation of the clock divisors is rather costly. On an iMX287,
using spidev with messages that consist of 511 transfers of 4 bytes each at
an SCK of 48 MHz, the effective transfer rate more than doubles from about
290 KB/sec to 600 KB/sec!
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
It can't be called with a NULL transfer anymore so it can be simplified
to not check for that.
Fix indention of line-wrapped code to Linux standard.
The transfer pointer can be const.
It's not necessary to check if the spi_transfer's speed_hz is zero, as
the spi core also fills it in from the spi_device. However, the spi
core does not check if spi_device's speed is zero so we have to do
that still.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
The spi core already checks for a slave setting mode bits that we
didn't list as supported when the master was registered. There is no
need to do it again in the master driver.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Despite many warnings in the SPI documentation and code, the spi-mxs
driver sets shared chip registers in the ->setup method. This method can
be called when transfers are in progress on other slaves controlled by the
master. Setting registers or any other shared state will corrupt those
transfers.
So fix mxs_spi_setup() to not call mxs_spi_setup_transfer().
mxs_spi_setup_transfer() is already called for each transfer when they
are actually performed in mxs_spi_transfer_one(), so the call in
mxs_spi_setup() isn't necessary to setup anything.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
The ssp struct has a clock rate field, to provide the actual value, in Hz,
of the SSP output clock (the rate of SSP_SCK) after mxs_ssp_set_clk_rate()
is called. It is set by mxs_ssp_set_clk_rate(), for SSP using drivers (like
SPI and MMC) to *read* if they want to know the actual clock rate. The SPI
driver isn't supposed to *write* to it.
For some reason the spi-mxs driver decides to write to this field on init,
and sets it to the value of the SSP input clock (clk_sspN, from the MXS
clocking block) in kHz. It shouldn't be setting the value, and certainly
shouldn't be setting it with the wrong clock in the wrong units.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Because the driver sets the SPI_MASTER_HALF_DUPLEX flag, the spi core
will check transfers to insure they are not full duplex. It's not
necessary to check that in the spi-mxs driver as well.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
In DMA mode the chip select control bits would be ORed into the CTRL0
register without first clearing the bits. This means that after
addressing slave 1, the CTRL0 bit to address slave 1 would be still be
set when addressing slave 0, resulting in slave 1 continuing to be
addressed.
The message handling function would pass the CS value to the txrx
function, which would re-program the bits on each transfer in the
message. The selected CS does not change during a message so this is
inefficient. It also means there are two different sets of code for
selecting the CS, one for PIO that worked and one for DMA that didn't.
Change the code to set the CS bits in the message handling function
once. Now the DMA and PIO txrx functions don't need to care about CS
at all.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
There are two bits which control the CS line in the CTRL0 register:
LOCK_CS and IGNORE_CRC. The latter would be better named DEASSERT_CS
in SPI mode.
Setting DEASSERT_CS causes CS to be de-asserted at the end of the transfer.
It should normally be set only for the final segment of the final transfer.
The DMA code explicitly sets it in this case, but because it never clears
the bit from the ctrl0 register, it will remain set for all transfers in
subsequent messages. This results in a CS pulse between transfers.
There is a similar problem with the read mode bit never being cleared
in DMA mode.
This patch fixes DEASSERT_CS and READ being left on in DMA mode.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
There are three flag arguments to the PIO and DMA txrx functions. Two
are passed as pointers to integers, even though they are input only
and not modified, which makes no sense to do. The third is passed as
an integer.
The compiler must use an argument register or stack variable for each
flag this way. Using bitflags in a single flag argument is more
efficient and produces smaller code, since all the flags can fit in a
single register. And all the flag arguments get cumbersome,
especially when more are added for things like GPIO chipselects.
The "first" flag is never used, so can just be deleted.
The "last" flag is renamed to DEASSERT_CS, since that's really what it
does. The spi_transfer cs_change flag means that CS might be
de-asserted on a transfer which is not last and not de-assert on the
last transfer, so it is not which transfer is the last we need to know
but rather the transfers after which CS should be de-asserted.
This also extends the driver to not ignore cs_change when setting the
DEASSERT_CS nee "last" flag.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
INGORE_CRC, better named DEASSERT_CS, should be cleared on all tranfers
except the last. So instead of only clearing it on the first transfer, we
can just always clear it. It will set on the last transfer.
This removes the only use of the "first" flag in the transfer functions, so
that flag can be then be removed.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
These functions consist of nothing but one single writel call and are
only called once. And the names really aren't accurate or clear,
since they don't enable or disble SPI. Rather they set the bit that
controls the state of CS at the end of transfer. It easier to follow
the code to just set this bit with a writel() along with all the other
bits being set in the same function.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
There are two bits which control the CS line in the CTRL0 register:
LOCK_CS and IGNORE_CRC. The latter would be better named DEASSERT_CS
in SPI mode.
LOCK_CS keeps CS asserted though the entire transfer. This should
always be set. The DMA code will always set it, explicitly on the
first segment of the first transfer, and then implicitly on all the
rest by never clearing the bit from the value read from the ctrl0
register.
The PIO code will explicitly set it for the first transfer, leave it
set for intermediate transfers, and then clear it for the final
transfer. It should not clear it.
The only reason to not set LOCK_CS would be to attempt an altered
protocol where CS pulses between each word. Though don't get your
hopes up if you want to do this, as the hardware doesn't appear to do
this in any sane manner. It appears to be related to the hardware
FIFO fill level.
The code can be simplified by just setting LOCK_CS once and then not
needing to deal with it at all in the PIO and DMA transfer functions.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Use devm_spi_register_master() to make cleanup paths simpler,
and remove a duplicate put.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The bits_per_word variable is not used after commit 24778be20f
"spi: convert drivers to use bits_per_word_mask".
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
As devm_ioremap_resource() is used on probe, there is no need to explicitly
check the return value from platform_get_resource(), as this is something that
devm_ioremap_resource() takes care by itself.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
stmp_reset_block() may fail, so let's check its return value and propagate it in
the case of error.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.
While at it, rename 'out_free_dma' to 'out_disable_clk' so that it can properly
describe its purpose.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
On mxs_spi_probe() the dma channels are requested prior to enabling the SSP
clock, so in the error path we should disable the SSP clock first and
release the DMA channels later.
Same logic applies in mxs_spi_remove().
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fill in the recently added spi_master.bits_per_word_mask field in as
many drivers as possible. Make related cleanups, such as removing any
redundant error-checking, or empty setup callbacks.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for handling pinctrl.
So remove devm_pinctrl_get_select_default() from the driver.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
These are mostly new device tree bindings for existing drivers, as well
as changes to the device tree source files to add support for those
devices, and a couple of new boards, most notably Samsung's Exynos5
based Chromebook.
The changes depend on earlier platform specific updates and touch
the usual platforms: omap, exynos, tegra, mxs, mvebu and davinci.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=G60S
-----END PGP SIGNATURE-----
Merge tag 'dt-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC device tree updates (part 2) from Arnd Bergmann:
"These are mostly new device tree bindings for existing drivers, as
well as changes to the device tree source files to add support for
those devices, and a couple of new boards, most notably Samsung's
Exynos5 based Chromebook.
The changes depend on earlier platform specific updates and touch the
usual platforms: omap, exynos, tegra, mxs, mvebu and davinci."
* tag 'dt-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (169 commits)
ARM: exynos: dts: cros5250: add EC device
ARM: dts: Add sbs-battery for exynos5250-snow
ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
ARM: dts: add mshc controller node for Exynos4x12 SoCs
ARM: dts: Add chip-id controller node on Exynos4/5 SoC
ARM: EXYNOS: Create virtual I/O mapping for Chip-ID controller using device tree
ARM: davinci: da850-evm: add SPI flash support
ARM: davinci: da850: override SPI DT node device name
ARM: davinci: da850: add SPI1 DT node
spi/davinci: add DT binding documentation
spi/davinci: no wildcards in DT compatible property
ARM: dts: mvebu: Convert mvebu device tree files to 64 bits
ARM: dts: mvebu: introduce internal-regs node
ARM: dts: mvebu: Convert all the mvebu files to use the range property
ARM: dts: mvebu: move all peripherals inside soc
ARM: dts: mvebu: fix cpus section indentation
ARM: davinci: da850: add EHRPWM & ECAP DT node
ARM/dts: OMAP3: fix pinctrl-single configuration
ARM: dts: Add OMAP3430 SDP NOR flash memory binding
ARM: dts: Add NOR flash bindings for OMAP2420 H4
...
With the generic DMA device tree helper supported by mxs-dma driver,
client devices only need to call dma_request_slave_channel() for
requesting a DMA channel from dmaengine.
Since mxs is a DT only platform now, along with the changes, the non-DT
case handling in probe function also gets removed.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers all
over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
If you need me to provide a merged tree to handle these resolutions,
please let me know.
Other than those patches, there's not much here, some minor fixes and
updates.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iEYEABECAAYFAlEmV0cACgkQMUfUDdst+yncCQCfbmnQZju7kzWXk6PjdFuKspT9
weAAoMCzcAtEzzc4LXuUxxG/sXBVBCjW
=yWAQ
-----END PGP SIGNATURE-----
Merge tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg Kroah-Hartman:
"Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers
all over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
Other than those patches, there's not much here, some minor fixes and
updates"
Fix up trivial conflicts
* tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits)
base: memory: fix soft/hard_offline_page permissions
drivercore: Fix ordering between deferred_probe and exiting initcalls
backlight: fix class_find_device() arguments
TTY: mark tty_get_device call with the proper const values
driver-core: constify data for class_find_device()
firmware: Ignore abort check when no user-helper is used
firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER
firmware: Make user-mode helper optional
firmware: Refactoring for splitting user-mode helper code
Driver core: treat unregistered bus_types as having no devices
watchdog: Convert to devm_ioremap_resource()
thermal: Convert to devm_ioremap_resource()
spi: Convert to devm_ioremap_resource()
power: Convert to devm_ioremap_resource()
mtd: Convert to devm_ioremap_resource()
mmc: Convert to devm_ioremap_resource()
mfd: Convert to devm_ioremap_resource()
media: Convert to devm_ioremap_resource()
iommu: Convert to devm_ioremap_resource()
drm: Convert to devm_ioremap_resource()
...
On MX23 the XFER_COUNT part in ctrl0 field in DMA descriptor was
improperly OR'd during the construction of DMA descriptor chain, instead
of being freshly set. Because of that too many bytes were being
expected from SPI during the last DMA cycle. This caused a timeout
(SSP_TIMEOUT) to happen in the processing of the last DMA descriptor,
and thus reads and writes were failing. This is a fix for the problem,
by clearing XFER_COUNT bytes in ctrl0 before setting the new XFER_COUNT
for DMA descriptor.
Signed-off-by: Juha Lumme <juha.lumme@gmail.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.
devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option. As result the __dev*
markings will be going away.
Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Bill Pemberton has done most of the legwork on this series. I've used
his script to purge the attributes from the drivers/gpio tree.
Reported-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
In case the SPI DMA times out, the DMA might still be in some kind of
inconsistent state. Issue dmaengine_terminate_all() on the particular
channel to kill off all operations before continuing.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
In the current code implementing the MXS SPI driver, every transferred
message had assigned status = 0, which is not correct. Properly assign
status returned from the I/O functions.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Add "clock-frequency" property, which allows configuring the SPI block's
base speed.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Rework the mxs_ssp_timeout() function to make it a bit more readable
and hopefully less error prone. Also, have only one successful exit
from the function and one failing exit instead of two.
Finally, discard the udelay() from this function altogether, as this
tightloop is quick enough it's pointless.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This driver checks the length of transfer to be made and based
on this information, either chooses to transfer data via DMA or
PIO. Decrement this border further to gain better performace eg.
during SPI flash writes.
Empiric measurement shows that this gives extra 3kB/s write speed
with a M25P80 flash clocked at 40MHz.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The transfer function incremented (struct spi_message)->actual_length
unconditionally, even if the transfer failed. Rectify this by incrementing
this only if transfer succeeded.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
When doing long continuous transfer, eg. from SPI flash via /dev/mtd,
the driver dies. This is caused by a bug in the DMA chaining. Rework
the DMA transfer code so that this issue does not happen any longer.
This involves proper allocation of correct amount of sg-list members.
Also, this means proper creation of DMA descriptors. There is actually an
important catch to this, the data transfer descriptors must be interleaved
with PIO register write descriptor, otherwise the transfer stalls. This
can be done in one descriptor, but due to the limitation of the DMA API,
it's not possible.
It turns out that in order for the SPI DMA to properly support
continuous transfers longer than 65280 bytes, there are some very
important parts that were left out from the documentation about about
the PIO transfer that is used.
Firstly, the XFER_SIZE register is not written with the whole length
of a transfer, but is written by each and every chained descriptor
with the length of the descriptors data buffer.
Next, unlike the demo code supplied by FSL, which only writes one PIO
word per descriptor, this does not apply if the descriptors are chained,
since the XFER_SIZE register must be written. Therefore, it is essential
to use four PIO words, CTRL0, CMD0, CMD1, XFER_SIZE. CMD0 and CMD1 are
written with zero, since they don't apply. The DMA programs the PIO words
in an incrementing order, so four PIO words.
Finally, unlike the demo code supplied by FSL, the SSP_CTRL0_IGNORE_CRC
must not be set during the whole transfer, but it must be set only on the
last descriptor in the chain.
Lastly, this code lends code from drivers/mtd/nand/omap2.c, which solves
trouble when the buffer supplied to the DMA transfer was vmalloc()'d. So
with this patch, it's safe to use /dev/mtdblockX interface again.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The call sequence spi_alloc_master/spi_register_master/spi_unregister_master
is complete; it reduces the device reference count to zero, which results in
device memory being freed. The remove function accesses the freed memory after
the call to spi_unregister_master(), _and_ it calls spi_master_put on the freed
memory.
Acquire a reference to the SPI master device and release it after cleanup is
complete (with the existing spi_master_put) to solve the problem.
Also, the device subsystem ensures that the remove function is only called once,
and resets device driver data to NULL. Remove the unnecessaary calls to
platform_set_drvdata().
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The init_completion() call does reinit not only the variable carrying
the flag that the completion finished, but also initialized the
waitqueue associated with the completion. On the contrary, the
INIT_COMPLETION() call only reinits the flag.
In case there was anything still stuck in the waitqueue, subsequent call
to init_completion() would be able to create possible race condition. This
patch uses the proper function and moves init_completion() into .probe() call
of the driver, to be issued only once.
Note that such scenario is impossible, since two threads can never enter the
mxs_spi_txrx_dma(), since whole this section is protected by mutex in SPI core.
This by no means allows this issue to exit though.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Restart the SSP block in case the SSP transfer failed in any way.
The block hung in some cases otherwise.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Chris Ball <cjb@laptop.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
These parts will be used by the MXS SPI driver too.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Chris Ball <cjb@laptop.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This is slightly reworked version of the SPI driver.
Support for DT has been added and it's been converted
to queued API.
Based on previous attempt by:
Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Chris Ball <cjb@laptop.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
