Rework Davinci SPI driver to store GPIO CS number in cs_gpio field
of SPI device structure (spi_device) for both DT and non-DT cases.
This will make Davinci SPI driver code simpler and allows to reuse
more SPI core functionality.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Currently driver supports only configuration of GPIO CS through
platform data. This patch enhances the driver to configure GPIO
CS through DT. Also update the DT binding documentation to
reflect the availability of cs-gpios.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Currently, the driver defines SPI_MAX_CHIPSELECT as 2 and
use per device array bytes_per_word based on this. This breaks
if num_chipselect per device is greater than 2. This patch
fix this and allocate memory for this array based on
num_chipselect.

It's preparation patch to enable GPIO CS feature for
Davinci SPI.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

It's pointless to use of_match_ptr within CONFIG_OF guard.
Use of_match_ptr around davinci_spi_of_match when setting .of_match_table.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

spi_master_get_devdata() never returns NULL when spi_alloc_master() success,
so remove NULL test for dspi.
We have ensured master is not NULL before assigning it to dspi->bitbang.master.
So also remove NULL test for dspi->bitbang.master.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

The implementation in spi_setup() already set spi->bits_per_word = 8 when
spi->bits_per_word is 0 before calling spi->master->setup.
So we don't need to do it again in setup() callback.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Acked-by: NMarek Vasut <marex@denx.de>
Acked-by: NBarry Song <Baohua.Song@csr.com>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NMark Brown <broonie@linaro.org>

Use devm_*() functions to make cleanup paths simpler.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

With CONFIG_ARM_LPAE=y spi driver throws below warning

drivers/spi/spi-davinci.c: In function ‘davinci_spi_probe’:
drivers/spi/spi-davinci.c:965:3: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘resource_size_t’ [-Wformat]
drivers/spi/spi-davinci.c:965:3: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘resource_size_t’ [-Wformat]

Lets use '%pa' to properly print 'resource_size_t' type variables.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NMark 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: NWolfram 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many drivers that use bitbang library have a leak on probe error paths.
This is because once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory.

Fix this issue by moving the code taking a reference to master to
spi_bitbang_start(), so spi_bitbang_start() will take a reference to master on
success. With this change, the caller is responsible for calling
spi_bitbang_stop() to decrement the reference and spi_master_put() as
counterpart of spi_alloc_master() to prevent a memory leak.

So now we have below patten for drivers using bitbang library:

probe:
spi_alloc_master        -> Init reference count to 1
spi_bitbang_start       -> Increment reference count
remove:
spi_bitbang_stop        -> Decrement reference count
spi_master_put          -> Decrement reference count (reference count reaches 0)

Fixup all users accordingly.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Suggested-by: NUwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Acked-by: NUwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMark Brown <broonie@linaro.org>

Many drivers that use bitbang library have a leak on probe error paths.
This is because once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory.

Fix this issue by moving the code taking a reference to master to
spi_bitbang_start(), so spi_bitbang_start() will take a reference to master on
success. With this change, the caller is responsible for calling
spi_bitbang_stop() to decrement the reference and spi_master_put() as
counterpart of spi_alloc_master() to prevent a memory leak.

So now we have below patten for drivers using bitbang library:

probe:
spi_alloc_master        -> Init reference count to 1
spi_bitbang_start       -> Increment reference count
remove:
spi_bitbang_stop        -> Decrement reference count
spi_master_put          -> Decrement reference count (reference count reaches 0)

Fixup all users accordingly.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Suggested-by: NUwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Acked-by: NUwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMark Brown <broonie@linaro.org>

'prescale' contains the return value of davinci_spi_get_prescale()
which is a signed integer. Convert 'prescale' to integer to silence
the following warning:
drivers/spi/spi-davinci.c:318 davinci_spi_setup_transfer() warn:
unsigned 'prescale' is never less than zero.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Commit 048177ce (spi: spi-davinci:
convert to DMA engine API) introduced a regression: dma_map_single()
is called with direction DMA_FROM_DEVICE for rx and for tx.
Signed-off-by: NChristian Eggers <ceggers@gmx.de>
Acked-by: NMatt Porter <mporter@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org # v3.7.x+

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: NStephen Warren <swarren@wwwdotorg.org>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Follow DT naming convention for compatible property of the blob.
Use first chip name that introduced the specific version of the
device.
Signed-off-by: NManjunathappa, Prakash <prakash.pm@ti.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Fix below module build error:

  CC [M]  drivers/spi/spi-davinci.o
drivers/spi/spi-davinci.c:774:1: error: '__mod_of_device_table' aliased
to undefined symbol 'davini_spi_of_match'
drivers/spi/spi-davinci.c:774:1: error: '__mod_of_device_table' aliased
to undefined symbol 'davini_spi_of_match'
make[2]: *** [drivers/spi/spi-davinci.o] Error 1
make[1]: *** [drivers/spi] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [drivers] Error 2
Signed-off-by: NManjunathappa, Prakash <prakash.pm@ti.com>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

With RT pre-empt patch applied to Linux kernel, the irq handler will be
force converted to an irq thread. spi driver can get back to back messages
from the slave device. In such cases, IRQ thread doesn't get a chance to
run to read the slave data. Hence the irq handler must be run in hard irq
context to read/write data from slave device. Otherwise, the kernel goes
into a deadlock. This patch fixes this issue when PREEMPT_RT_FULL is
enabled in the kernel. A dummy thread function is provided to satisfy the
request_threaded_irq() API. Passing a NULL for function also causes the
irq handler to be executed in the thread context.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This adds OF support to DaVinci SPI controller to configure platform
data through device bindings. Also replaces clk_enable() with
of clk_prepare_enable() as well as clk_disable() with
clk_disable_unprepare().
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

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: NBill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the davinci include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: "Ben Dooks" <ben-linux@fluff.org>
Cc: "Wolfram Sang" <w.sang@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Liam Girdwood <lrg@ti.com>
Cc: davinci-linux-open-source@linux.davincidsp.com

Removes use of the DaVinci EDMA private DMA API and replaces
it with use of the DMA engine API.
Signed-off-by: NMatt Porter <mporter@ti.com>
Tested-by: NTom Rini <trini@ti.com>
Tested-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

The driver uses NULL for dma_unmap_single instead of
the struct device that the API expects.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Tested-by: NAkshay Shankarmurthy <akshay.s@ti.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

For simple modules that contain a single platform_driver without any
additional setup code then ends up being a block of duplicated
boilerplate.  This patch adds a new macro, module_platform_driver(),
which replaces the module_init()/module_exit() registrations with
template functions.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: NMagnus Damm <magnus.damm@gmail.com>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

The current davinci SPI driver, in DMA mode, is limited to 65535
words for a single transfer.  Modify the driver by configuring a
3 dimensional EDMA transfer to support up to 65535x65535
words.
Signed-off-by: NMichael Williamson <michael.williamson@criticallink.com>
Tested-by: NStefano Babic <sbabic@denx.de>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The davinci spi driver provides an option to use DMA transfers for
data.  In the dma_map_single() call, the driver is passing the
number of words to be transfered for the mapping size.  It should
be the number of bytes.
Signed-off-by: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

For DMA operation, the davinci spi driver needs an event queue number.
Currently, this number is passed as a IORESOURCE_DMA.  This is not
correct, as the event queue is not a DMA channel.  Pass the event queue
via the platform data structure instead.

On dm355 and dm365, move the eventq assignment for spi0 out of resources
array and into platform data.
Signed-off-by: NMichael Williamson <michael.williamson@criticallink.com>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Shorten names of local variables and structure members where
possible.

Local variables:

* 'davinci_spi' is being renamed 'dspi'
* 'davinci_spi_dma' is being renamed 'dma'

Structure members:

* 'dma_{tx|rx}_channel' is being renamed '{tx|rx}_channel'
  since the structure containing them is already called
  'davinci_spi_dma'

* 'davinci_spi_dma' in 'davinci_spi' structure is being
  renamed 'dma'
Tested-By: NBrian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Remove unnecesary private data member 'region_size'
being used to store the size of SPI memory region.

Instead, get the memory resource size directly from
the platform data.
Tested-By: NBrian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Add copyright for EF Johnson Technologies since the driver
has been majorly overhauled by Brian.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Add comments describing the platform data members
and per-chip-select SPI configuration structure.

Also, add some comments describing the what happens
during the driver probe.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Setup the owner member of the platform driver to THIS_MODULE
instead of leaving it NULL.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Enable SPI only when active transfers are in progress. Keep
it in local low power when not in use.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

The "clk_internal" platform data member which contols the
CLKMOD bit in Global Control Register 1 is not useful
since CLKMOD needs be set to 1 *always* to ensure master
mode operation.

Remove this platform data.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Let DMA operation be specified on a per-device basis instead
of selecting it once during probe.

A side effect of this is the need to combine the PIO and DMA buffer
txrx_bufs routine. This is good since they anyway share some common
functionality.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

The DMA code does not use the existing completion variable 'done'
which is being used for interrupt mode transfers. Instead it uses
two different completion variables specific to DMA mode transfers.

Eliminate the usage of new completion variables for DMA mode and
use the existing completion variable.

[nsekhar@ti.com: To make this process easy, eliminate the two
different DMA completion callback functions for tx and rx and
use a single callback function instead]
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Do not simply clean the DMA channel on a DMA completion
error. Instead, use wcount and rcount members of davinci_spi
to detecion non-completion of DMA and signal EIO to the
application.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Use a dummy param slot linked to itself to take care of the
extra "sync event" that gets sent to EDMA controller after
the last byte has been transferred.

The dummy PaRAM slot that is linked to the actual DMA PaRAM
slot "absorbs" this event and prevents a EDMA CC error to
be asserted.

Without this provision, the EDMA CC error would be asserted
because the channel PaRAM would be empty after the transfer
and EDMA would not know what to make out of the extra sync
event.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>