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>

Do not allocate (and de-allocate) SPI DMA channels during setup
(and cleanup) for each SPI device. Instead, allocate the DMA
channels once duing probe and use them for the life time of
the driver.

This makes sense since there are dedicated DMA channels meant
for SPI use.

This also helps remove the unnecessary DMA "sync_dev" variables
being used to store DMA channel information.

Also, the "use_dma" platform variable is now eliminated since
it is possible to check if the platform supports DMA or not
based upon whether DMA resources can be found or not.
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Tested-By: NBrian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Do not stop SPI DMA event generation in either transmit or
receive DMA event call back because the single setting affects
both transmit and receive event generation.

Depending on the order in which the callbacks happen, transmit
or receive events can get unintentionally stalled.

Instead, disable event generation once after both the transmit
and receive DMA completes.

While at it, remove the largely under-used function to set or
clear DMA event generation.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Currently a series of EDMA API calls are being made to setup
various aspects of EDMA PaRAM slots for receive and transmit.

Instead setup the PaRAM using a local structure and write once
to the hardware using edma_write_slot()
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

In keeping with the full duplex nature of the SPI bus. Always
start receive DMA along with transmit DMA.

If there is no receive buffer provided with the transfer, use
a temporary buffer to receive the data to be thrown away.

[michael.williamson@criticallink.com: receive DMA size should
be same as transfer length to avoid hang-up when transfer length
is smaller than temporary rx buffer size (rx buffer not provided)]
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Remove usage of temporary buffer when no transmit data is provided.
Instead, use the transmit register itself as the source of data.

By choosing the transmit register itself as the source of data, this
patch helps remove unnecessary accesses to memory when no real data
is being transmitted.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

Due to the full duplex nature of the SPI bus, the SPI master
on DaVinci needs transmit to be active even if the tranfer is
only meant to collect receive data.

The current code achieves this by using a temporary zeroed buffer
to provide DMA data in case the transfer does not have a transmit
buffer provided.

However, the transmit DMA is started only if transmit buffer is
provided rendering the temporary buffer unused. Instead the code
relies on a write to SPIDAT1 register to trigger transmit operation.
This however only sends two bytes of data.

Fix this by starting transmit DMA always.

This changes exposes a bug on DM355 where the CSHOLD bit in
SPIDAT1 needs to be written to in between transfers. Handle
that by introducing a "cshold_bug" platform data which is
set to true for DM355.
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 store DMA channel related information per chip-select since
that information does not depend on the chip select.

The same DMA channels can be used for transfers on all chip-selects
since the transfer happens one-at-a-time.
Signed-off-by: NBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: NMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>