The ctlr->idling flag is never checked now, so we don't need to set it
either.
Signed-off-by: NDavid Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-8-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

The interaction with the controller message queue and its corresponding
auxiliary flags and variables requires the use of the queue_lock which is
costly. Since spi_sync will transfer the complete message anyway, and not
return until it is finished, there is no need to put the message into the
queue if the queue is empty. This can save a lot of overhead.

As an example of how significant this is, when using the MCP2518FD SPI CAN
controller on a i.MX8MM SoC, the time during which the interrupt line
stays active (during 3 relatively short spi_sync messages), is reduced
from 98us to 72us by this patch.
Signed-off-by: NDavid Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-3-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

This enables the possibility to transfer a message that is not at the
current tip of the async message queue.
This is in preparation of the next patch(es) which enable spi_sync messages
to skip the queue altogether.
Signed-off-by: NDavid Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-2-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

On 32 bit systems, the following kernel BUG is hit:

BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x18/0x24
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
 dump_backtrace from show_stack+0x20/0x24
 r7:81024ffd r6:00000000 r5:81024ffd r4:60000013
 show_stack from dump_stack_lvl+0x60/0x78
 dump_stack_lvl from dump_stack+0x14/0x1c
 r7:81024ffd r6:80f652de r5:80bec180 r4:819a2500
 dump_stack from check_preemption_disabled+0xc8/0xf0
 check_preemption_disabled from debug_smp_processor_id+0x18/0x24
 r8:8119b7e0 r7:81205534 r6:819f5c00 r5:819f4c00 r4:c083d724
 debug_smp_processor_id from __spi_sync+0x78/0x220
 __spi_sync from spi_sync+0x34/0x4c
 r10:bb7bf4e0 r9:c083d724 r8:00000007 r7:81a068c0 r6:822a83c0 r5:c083d724
 r4:819f4c00
 spi_sync from spi_mem_exec_op+0x338/0x370
 r5:000000b4 r4:c083d910
 spi_mem_exec_op from spi_nor_read_id+0x98/0xdc
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:82358040
 r4:819f7c40
 spi_nor_read_id from spi_nor_detect+0x38/0x114
 r7:82358040 r6:00000000 r5:819f7c40 r4:819f7c40
 spi_nor_detect from spi_nor_scan+0x11c/0xbec
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:c083da4c r6:00000000 r5:00010101
 r4:819f7c40
 spi_nor_scan from spi_nor_probe+0x10c/0x2d0
 r10:bb7bf4e0 r9:bb7bf4d0 r8:00000000 r7:819f4c00 r6:00000000 r5:00000000
 r4:819f7c40

per-cpu access needs to be guarded against preemption.

Fixes: 6598b91b ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDavid Jander <david@protonic.nl>
Tested-by: NNícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

Fixes these "make htmldocs" warnings:

include/linux/spi/spi.h:82: warning: Function parameter or member 'syncp' not described in 'spi_statistics'
include/linux/spi/spi.h:213: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_device'
include/linux/spi/spi.h:676: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_controller'

Fixes: 6598b91b ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid Jander <david@protonic.nl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220608153309.2899565-1-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

This change gives a dramatic performance improvement in the hot path,
since many costly spin_lock_irqsave() calls can be avoided.

On an i.MX8MM system with a MCP2518FD CAN controller connected via SPI,
the time the driver takes to handle interrupts, or in other words the time
the IRQ line of the CAN controller stays low is mainly dominated by the
time it takes to do 3 relatively short sync SPI transfers. The effect of
this patch is a reduction of this time from 136us down to only 98us.
Suggested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220524091808.2269898-1-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

Spelling mistake (triple letters) in comment.
Detected with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220521111145.81697-13-Julia.Lawall@inria.frSigned-off-by: NMark Brown <broonie@kernel.org>

This fixes the corresponding warnings during building the docs.
Signed-off-by: NSiddh Raman Pant <siddhpant.gh@gmail.com>
Link: https://lore.kernel.org/r/4e6187a4-d0f8-4750-e407-e09cc1c91789@gmail.comSigned-off-by: NMark Brown <broonie@kernel.org>

Use a helper to set driver_override to the reduce amount of duplicated
code.
Reviewed-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-8-krzysztof.kozlowski@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit d40f0b6f instroduced last_cs_enable to avoid setting
chipselect if it's not necessary, but it also introduces a bug. The
chipselect may not be set correctly on multi-device SPI busses. The
reason is that we can't judge the chipselect by bool last_cs_enable,
since chipselect may be modified after other devices were accessed.

So we should record the specific state of chipselect in case of
confusion.
Signed-off-by: NYun Zhou <yun.zhou@windriver.com>
Link: https://lore.kernel.org/r/20220217141234.72737-1-yun.zhou@windriver.comSigned-off-by: NMark Brown <broonie@kernel.org>

All drivers using GPIOs as chip select have been rewritten to use
GPIO descriptors passing the ->use_gpio_descriptors flag. Retire
the code and fields used by the legacy GPIO API.

Do not drop the ->use_gpio_descriptors flag: it now only indicates
that we want to use GPIOs in addition to native chip selects.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220210231954.807904-1-linus.walleij@linaro.orgSigned-off-by: NMark Brown <broonie@kernel.org>

Create a spi_controller_mem_caps structure and put it within the
spi_controller structure close to the spi_controller_mem_ops
strucure. So far the only field in this structure is the support for dtr
operations, but soon we will add another parameter.

Also create a helper to parse the capabilities and check if the
requested capability has been set or not.
Signed-off-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: NPratyush Yadav <p.yadav@ti.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: NMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-2-miquel.raynal@bootlin.com

The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NJérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NClaudius Heine <ch@denx.de>
Acked-by: NStefan Schmidt <stefan@datenfreihafen.org>
Acked-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: NMarcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: NŁukasz Stelmach <l.stelmach@samsung.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.deSigned-off-by: NMark Brown <broonie@kernel.org>

Some ACPI nodes may have more than one Spi Resource.
To be able to handle these case, its necessary to have
a way of counting these resources.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

If a node contains more than one SPI resource it may be necessary to
use an index to select which one you want to allocate a spi device for.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

This functions were previously made private since they
were not used. However, these functions will be needed
again.

Partial revert of commit da21fde0
("spi: Make several public functions private to spi.c")
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-2-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

Some ACPI nodes may have more than one Spi Resource.
To be able to handle these case, its necessary to have
a way of counting these resources.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

If a node contains more than one SPI resource it may be necessary to
use an index to select which one you want to allocate a spi device for.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

This functions were previously made private since they
were not used. However, these functions will be needed
again.

Partial revert of commit da21fde0
("spi: Make several public functions private to spi.c")
Signed-off-by: NStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-2-sbinding@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>

Commit b42faeee ("spi: Add a PTP system timestamp
to the transfer structure") added an include of ptp_clock_kernel.h
to spi.h for struct ptp_system_timestamp but a forward declaration
is enough. Let's use that to limit the number of objects we have
to rebuild every time we touch networking headers.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Tested-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210904013140.2377609-1-kuba@kernel.orgSigned-off-by: NMark Brown <broonie@kernel.org>

Currently we have a global spi_add_lock which we take when adding new
devices so that we can check that we're not trying to reuse a chip
select that's already controlled.  This means that if the SPI device is
itself a SPI controller and triggers the instantiation of further SPI
devices we trigger a deadlock as we try to register and instantiate
those devices while in the process of doing so for the parent controller
and hence already holding the global spi_add_lock.  Since we only care
about concurrency within a single SPI bus move the lock to be per
controller, avoiding the deadlock.

This can be easily triggered in the case of spi-mux.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

All these functions have no callers apart from drivers/spi/spi.c. So
drop their declarations in include/linux/spi/spi.h and don't export
them.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211007121415.2401638-5-u.kleine-koenig@pengutronix.deSigned-off-by: NMark Brown <broonie@kernel.org>

The last user is gone since commit

	2962db71 ("staging/fbtft: Remove fbtft_device")

in 2019.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211007121415.2401638-3-u.kleine-koenig@pengutronix.deSigned-off-by: NMark Brown <broonie@kernel.org>

This patch modified set_cs_timing parameter, no need pass in spi_delay
to set_cs_timing callback.
By the way, we modified the mediatek and tegra114 spi driver to fix build err.
In mediatek spi driver, We have support set absolute time not clk_count,
and call this function in prepare_message not user's API.
Signed-off-by: NMason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210804133746.6742-1-Mason.Zhang@mediatek.comSigned-off-by: NMark Brown <broonie@kernel.org>

As we know, spi core layer has removed spi_set_cs_timing() API.
So this patch moved spi_delay for cs_timing from spi_controller
to spi_device, because cs timing should be set by spi_device but
not controller.
Signed-off-by: NMason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210804133716.32040-1-Mason.Zhang@mediatek.comSigned-off-by: NMark Brown <broonie@kernel.org>

Fix kernel-doc warning in spi.h by adding the missing kernel-doc entry
and also correct the original comment so that they both indicate the
correct polarity of the flag.

../include/linux/spi/spi.h:673: warning: Function parameter or member 'devm_allocated' not described in 'spi_controller'

Fixes: 794aaf01 ("spi: Fix use-after-free with devm_spi_alloc_*")
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: William A. Kennington III <wak@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Reviewed-by: NLukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20210628210520.5712-1-rdunlap@infradead.orgSigned-off-by: NMark Brown <broonie@kernel.org>

Some controllers like qcom geni need the parent device to be used for
dma mapping, so add a dma_map_dev field and let drivers fill this to be
used as mapping device
Signed-off-by: NVinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.orgSigned-off-by: NMark Brown <broonie@kernel.org>

Introduce support for ancillary devices, similar to existing
implementation for I2C. This is useful for devices having
multiple chip-selects, for example some microcontrollers
provide a normal SPI interface and a flashing SPI interface.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20210621175359.126729-2-sebastian.reichel@collabora.comSigned-off-by: NMark Brown <broonie@kernel.org>

No one seems to be using this global and exported function, so remove it
as it is no longer needed.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210609071918.2852069-1-gregkh@linuxfoundation.orgSigned-off-by: NMark Brown <broonie@kernel.org>

While fixing undefined behaviour the commit f60d7270 ("spi: Avoid
undefined behaviour when counting unused native CSs") missed the case
when all CSs are GPIOs and thus unused_native_cs will be evaluated to
-1 in unsigned representation. This will falsely trigger a condition
in the spi_get_gpio_descs().

Switch to signed types for *_native_cs SPI controller fields to fix above.

Fixes: f60d7270 ("spi: Avoid undefined behaviour when counting unused native CSs")
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131242.49455-1-andriy.shevchenko@linux.intel.comSigned-off-by: NMark Brown <broonie@kernel.org>

We can't rely on the contents of the devres list during
spi_unregister_controller(), as the list is already torn down at the
time we perform devres_find() for devm_spi_release_controller. This
causes devices registered with devm_spi_alloc_{master,slave}() to be
mistakenly identified as legacy, non-devm managed devices and have their
reference counters decremented below 0.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174
[<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98)
[<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24)
 r4:b6700140
[<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40)
[<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4)
 r5:b6700180 r4:b6700100
[<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60)
 r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10
[<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec)
 r5:b117ad94 r4:b163dc10
[<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0)
 r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10
[<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8)

Instead, determine the devm allocation state as a flag on the
controller which is guaranteed to be stable during cleanup.

Fixes: 5e844cc3 ("spi: Introduce device-managed SPI controller allocation")
Signed-off-by: NWilliam A. Kennington III <wak@google.com>
Link: https://lore.kernel.org/r/20210407095527.2771582-1-wak@google.comSigned-off-by: NMark Brown <broonie@kernel.org>

struct spi_transfer is declared twice. One is declared at 24th line.
The blew one is not needed though. Remove the duplicate.
Signed-off-by: NWan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20210401065904.994121-1-wanjiabing@vivo.comSigned-off-by: NMark Brown <broonie@kernel.org>

>From now on only accepting complete software nodes.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-5-heikki.krogerus@linux.intel.comSigned-off-by: NMark Brown <broonie@kernel.org>

Making it possible for the drivers to assign complete
software fwnodes to the devices instead of only the device
properties in those nodes.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-2-heikki.krogerus@linux.intel.comSigned-off-by: NMark Brown <broonie@kernel.org>

The 'delay' field in the spi_transfer struct is meant to replace the
'delay_usecs' field. However some cleanup was required to remove the
uses of 'delay_usecs'. Now that it's been cleaned up, we can remove it
from the kernel tree.
Signed-off-by: NAlexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210308145502.1075689-10-aardelean@deviqon.comSigned-off-by: NMark Brown <broonie@kernel.org>

s/provied/provided/
Signed-off-by: NBhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20210208114928.32241-1-unixbhaskar@gmail.comSigned-off-by: NMark Brown <broonie@kernel.org>

This patch marks dummy transfer by setting dummy_data bit to 1.

Controllers supporting dummy transfer by hardware use this bit field
to skip software transfer of dummy bytes and use hardware dummy bytes
transfer.
Signed-off-by: NSowjanya Komatineni <skomatineni@nvidia.com>
Link: https://lore.kernel.org/r/1608585459-17250-6-git-send-email-skomatineni@nvidia.comSigned-off-by: NMark Brown <broonie@kernel.org>

Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
might be missing from an ADC while for a DAC the MISO/RX line may be
optional. This patch adds these two new modes: SPI_NO_TX and
SPI_NO_RX. This way, the drivers will be able to identify if any of
these two lines is missing and to adjust the transfers accordingly.
Signed-off-by: NDragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.comSigned-off-by: NMark Brown <broonie@kernel.org>