The kernel-doc has to be just before the structure definition but the one
for struct spi_replaced_transfers was before a structure declaration and
that confuses kernel-doc which complains with the following build error:

.//include/linux/spi/spi.h:933: error: Cannot parse struct or union!
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fixes docbook parsing error because documentation
is not directly followed by the structure, but typedef
used in structure.

Reordering should solve that issue.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

In addition to providing direct access to SPI bus, some spi controller
hardwares (like ti-qspi) provide special port (like memory mapped port)
that are optimized to improve SPI flash read performance.
This means the controller can automatically send the SPI signals
required to read data from the SPI flash device.
For this, SPI controller needs to know flash specific information like
read command to use, dummy bytes and address width.

Introduce spi_flash_read() interface to support accelerated read
over SPI flash devices. SPI master drivers can implement this callback to
support interfaces such as memory mapped read etc. m25p80 flash driver
and other flash drivers can call this make use of such interfaces. The
interface should only be used with SPI flashes and cannot be used with
other SPI devices.
Signed-off-by: NVignesh R <vigneshr@ti.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add spi_split_transfers_maxsize method that splits
spi_transfers transparently into multiple transfers
that are below the given max-size.

This makes use of the spi_res framework via
spi_replace_transfers to allocate/free the extra
transfers as well as reverting back the changes applied
while processing the spi_message.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add the spi_replace_transfers method that can get used
to replace some spi_transfers from a spi_message with other
transfers.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

SPI resource management framework used while processing a spi_message
via the spi-core.

The basic idea is taken from devres, but as the allocation may happen
fairly frequently, some provisioning (in the form of an unused spi_device
pointer argument to spi_res_alloc) has been made so that at a later stage
we may implement reuse objects allocated earlier avoiding the repeated
allocation by keeping a cache of objects that we can reuse.

This framework can get used for:
* rewriting spi_messages
  * to fullfill alignment requirements of the spi_master HW
  * to fullfill transfer length requirements
    (e.g: transfers need to be less than 64k)
  * consolidate spi_messages with multiple transfers into a single transfer
  when the total transfer length is below a threshold.
* reimplement spi_unmap_buf without explicitly needing to check if it has
  been mapped
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

In Windows it is up to the SPI host controller driver to handle the ACPI
DeviceSelection as it likes. The SPI core does not take any part in it.
This is different in Linux because we always expect to have chip select in
range of 0 .. master->num_chipselect - 1.

In order to support this in Linux we need a way to allow the driver to
translate between ACPI DeviceSelection field and Linux chip select number
so provide a new optional hook ->fw_translate_cs() that can be used by a
driver to handle translation and call this hook if set during SPI slave
ACPI enumeration.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fix kernel-doc warning for missing struct field notation.

..//include/linux/spi/spi.h:540: warning: No description found for parameter 'max_transfer_size'

[Meaningful subject -- broonie]
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

On some SPI controllers it is not feasible to transfer arbitrary amount
of data at once.

When the limit on transfer size is a few kilobytes at least it makes
sense to use the SPI hardware rather than reverting to gpio driver.

The protocol drivers need a way to check that they do not sent overly
long messages, though.
Signed-off-by: NMichal Suchanek <hramrach@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

In the spi_loopback_test driver there is the need to initialize
a spi_message that is filled with values from a static structure.

Applying spi_message_init to such a prefilled structure results in
all the settings getting reset to zero, which is not what we want.
Copying each field of spi_message separately instead always includes
the risk that some new fields have not been implemented in the copying
code.

So here we introduce a version of spi_message_init called
spi_message_init_no_memset that does not fill the structure
with zero first, but only initializes the relevant list_heads.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Uninline spi_unregister_device() in preparation of adding more code to
it. Add kerneldoc documentation while we're at it.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add spi_register_driver helper macro that adds THIS_MODULE to
spi_driver for the registering driver. We rename and modify
the existing spi_register_driver to enable this.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

When building docs with make htmldocs, warnings about not having
a description for the return value are reported, i.e:

warning: No description found for return value of 'spi_write'

Fix these by following the kernel-doc conventions explained in
Documentation/kernel-doc-nano-HOWTO.txt.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use for struct pxa2xx_spi_master clock_enable field was removed years ago
from the pxa2xx-spi driver by the commit 2f1a74e5 ("[ARM] pxa: make
pxa2xx_spi driver use ssp_request()/ssp_free()").

Therefore remove it from structure definition, documentation and from
couple affected board files.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>

report transfer sizes as a histogram via the following files:
  /sys/class/spi_master/spi*/statistics/transfer_bytes_histo_*
  /sys/class/spi_master/spi*/spi*.*/statistics/transfer_bytes_histo_*
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

chipselect (in the case of spi-gpio: spi_gpio_chipselect, which
calls gpiod_set_raw_value_cansleep) can sleep, so we should not
hold a spinlock while calling it from spi_bitbang_setup.

This issue was introduced by this commit, which converted spi-gpio
to cansleep variants:
d9dda5a1 "spi: spi-gpio: Use 'cansleep' variants to access GPIO"

Replacing the lock variable by a mutex fixes the issue: This is
safe as all instances where the lock is used are called from
contexts that can sleep.

Finally, update spi-ppc4xx and and spi-s3c24xx to use mutex
functions, as they directly hold the lock for similar purpose.
Signed-off-by: NNicolas Boichat <drinkcat@chromium.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fix the following 'make htmldocs' warnings:

  .//include/linux/spi/spi.h:71: warning: No description found for parameter 'lock'
  .//include/linux/spi/spi.h:71: warning: Excess struct/union/enum/typedef member 'clock' description in 'spi_statistics'
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

per spi-master statistics accessible as:
  /sys/class/spi_master/spi*/statistics/*

per spi-device statistics accessible via:
  /sys/class/spi_master/spi*/spi*.*/statistics/*

The following statistics are exposed as separate "files" inside
these directories:
* messages              number of spi_messages
* transfers             number of spi_transfers
* bytes                 number of bytes transferred
* bytes_rx              number of bytes transmitted
* bytes_tx              number of bytes received
* errors                number of errors encounterd
* timedout              number of messages that have timed out
* spi_async             number of spi_messages submitted using spi_async
* spi_sync              number of spi_messages submitted using spi_sync
* spi_sync_immediate    number of spi_messages submitted using spi_sync,
                        that are handled immediately without a context switch
                        to the spi_pump worker-thread
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch changes tha way of handling of cc2591-cc2520 combination
by moving amplified variable from platform data to private data.
This will be useful in other sections like tx power support.
Signed-off-by: NVarka Bhadram <varkab@cdac.in>
Cc: Brad Campbell <bradjc5@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If a driver doesn't implement the master->handle_err() callback and an
SPI transfer fails, the kernel will crash with a NULL pointer
dereference:

    Unable to handle kernel NULL pointer dereference at virtual address 00000000
    pgd = c0003000
    [00000000] *pgd=80000040004003, *pmd=00000000
    Internal error: Oops: 80000206 [#1] SMP ARM
    Modules linked in:
    CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc7-koelsch-05861-g1fc9fdd4add4f783 #1046
    Hardware name: Generic R8A7791 (Flattened Device Tree)
    task: eec359c0 ti: eec54000 task.ti: eec54000
    PC is at 0x0
    LR is at spi_transfer_one_message+0x1cc/0x1f0

Make the master->handle_err() callback optional to avoid the crash.

Also fix a spelling mistake in the callback documentation while we're at
it.

Fixes: b716c4ff ("spi: introduce master->handle_err() callback")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

The TI CC2521 is an RF power amplifier that is designed to interface
with the CC2520. Conveniently, it directly interfaces with the CC2520
and does not require any pins to be connected to a
microcontroller/processor. Adding a CC2591 increases the CC2520's range,
which is useful for border router and other wall-powered applications.

Using the CC2591 with the CC2520 requires configuring the CC2520 GPIOs
that are connected to the CC2591 to correctly set the CC2591 into TX and
RX modes. Further, TI recommends that the CC2520_TXPOWER and
CC2520_AGCCTRL1 registers are set differently to maximize the CC2591's
performance. These settings are covered in TI Application Note AN065.

This patch adds an optional `amplified` field to the cc2520 entry in the
device tree. If present, the CC2520 will be configured to operate with a
CC2591.

The expected pin mapping is:
CC2520 GPIO0 --> CC2591 EN
CC2520 GPIO5 --> CC2591 PAEN
Signed-off-by: NBrad Campbell <bradjc5@gmail.com>
Acked-by: NVarka Bhadram <varkabhadram@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

All SPI drivers have been converted from legacy suspend/resume callbacks to
dev_pm_ops. So we can finally remove support for legacy PM from the SPI
core.

Since there aren't any special bus specific things to do during
suspend/resume and since the PM core will automatically fallback directly to
using the device's PM ops if no bus PM ops are specified there is no need to
have any special SPI bus PM ops.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

This callback would be useful to handle an error that occurs in the generic
implementation of transfer_one_message(). The good candidate for this is to
drain FIFO and / or to terminate DMA transfers when timeout happened.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

alway -> always
Signed-off-by: NMarcin Bis <marcin@bis.org.pl>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds support for setting the xtal trim register. Some at86rf2xx
transceiver boards needs fine tuning the xtal capacitor.
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Move the include of mach/dma.h to the legacy PXA DMA code where it is used.
This enables building spi-pxa2xx on ARM64.
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The MSIOF controller has DTDL and SYNCDL in SITMDR1 register. So,
this patch adds new properties like the following commit:
  d0fb47a5
  (spi: fsl-espi: Configure FSL eSPI CSBEF and CSAFT)
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If we are using the standard SPI message pump (which all drivers should be
transitioning over to) then special case the message enqueue and instead of
starting the worker thread to push messages to the hardware do so in the
context of the caller if the controller is idle. This avoids a context
switch in the common case where the controller has a single user in a
single thread, for short PIO transfers there may be no need to context
switch away from the calling context to complete the transfer.

The code is a bit more complex than is desirable in part due to the need
to handle drivers not using the standard queue and in part due to handling
the various combinations of bus locking and asynchronous submission in
interrupt context.

It is still suboptimal since it will still wake the message pump for each
transfer in order to schedule idling of the hardware and if multiple
contexts are using the controller simultaneously a caller may end up
pumping a message for some random other thread rather than for itself,
and if the thread ends up deferring due to another context idling the
hardware then it will just busy wait.  It can, however, have the benefit
of aggregating power up and down of the hardware when a caller performs
a series of transfers back to back without any need for the use of
spi_async().
Signed-off-by: NMark Brown <broonie@kernel.org>

This adds the function spi_transfer_is_last() which can be used by
drivers to know whether a given transfer is the last one in the
current message.
Signed-off-by: NBeniamino Galvani <b.galvani@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

That field has been deprecated in favour of getting the necessary
information from ACPI/DT.

However, we still need to deal systems that are PCI only (no ACPI to back
up). In order to support such systems, we allow the DMA filter function and
its corresponding parameter via pxa2xx_spi_master platform data. Then when
the pxa2xx_spi_dma_setup() doesn't find the channel via ACPI, it falls back
to use the given filter function.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Device tree is not enabled in some architecture where gpio
driver mcp23s08 is still required.

v2-changes:
- Parse device tree properties into platform data other than
  individual variables.
v3-changes:
- Use of_node in gpio_chip device structure, because the
  struct device * always has an of_node which is NULL when
  OF is not used.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

These are all arguments or fields that got added without updating the
kerneldoc comments.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Add DMA support to the MSIOF driver using platform data.

As MSIOF DMA is limited to 32-bit words (requiring byte/wordswapping for
smaller wordsizes), and the group length is limited to 256 words, DMA is
performed on two fixed pages, allocated and mapped at driver initialization
time.

Performance figures (in Mbps) on r8a7791/koelsch at different SPI clock
frequencies for 1024-byte and 4096-byte transfers:

                   1024 bytes           4096 bytes
  -  3.25 MHz: PIO  2.1, DMA  2.6 | PIO  2.8, DMA  3.1
  -  6.5  MHz: PIO  3.2, DMA  4.4 | PIO  5.0, DMA  5.9
  - 13    MHz: PIO  4.2, DMA  6.6 | PIO  8.2, DMA 10.7
  - 26    MHz: PIO  5.9, DMA 10.4 | PIO 12.4, DMA 18.4

Note that DMA is only faster than PIO for transfers that exceed the FIFO
size (typically 64 words / 256 bytes).

Also note that large transfers (larger than the group length for DMA, or
larger than the FIFO size for PIO), should use cs-gpio (with the
appropriate pinmux setup), as the hardware chipselect will be deasserted in
between chunks.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@linaro.org>

This patch adds the driver support for the cc2520 radio.

Driver support:
	- Tx and Rx of IEEE-802.15.4 packets
	- Energy Detection on channel
	- Setting the Channel for the radio. [b/w 11 - 26 channels]
	- Start and Stop the radio
	- h/w address filtering
Signed-off-by: NVarka Bhadram <varkab@cdac.in>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 16-bit DMA support doesn't fit well within the SPI core DMA framework,
as it needs to manage its own double-sized temporary buffers, for handling
the interleaved data.
Remove it, as there is no in-tree board code that sets
rspi_plat_data.dma_width_16bit.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@linaro.org>

This patch removes the platform data for the irq_type. We use instead
the irq_get_trigger_type function to get these flags which should
already configured by the interrupt controller.
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Spi v3 controller is not only used on Blackfin. So rename it
and use ioread/iowrite api to make it work on other platform.
Signed-off-by: NScott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

spi_bitbang_stop() never fails, so make it return void.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>