| Age | Commit message (Collapse) | Author |
|---|
|
Even if the flag use_gpio_descriptors is set, it is possible that
cs_gpiods was not allocated, which leads to a kernel crash.
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Fixes: 3e5ec1db8bfe ("spi: Fix SPI_CS_HIGH setting when using native and GPIO CS")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191024141309.22434-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: <stable@vger.kernel.org>
|
|
The current conditional for PCI ID matching is hard to read.
Introduce couple of temporary variables to increase readability
of the code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191021103625.4250-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This core supports either 8, 16 or 32 bits as word width. This value is only
settable on instantiation, and thus we need to support any of them by means
of the device tree.
Signed-off-by: Alvaro Gamez Machado <alvaro.gamez@hazent.com>
Link: https://lore.kernel.org/r/20191024110757.25820-3-alvaro.gamez@hazent.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The devm_ioremap_resource() has already a check for resource pointer
being NULL. No need to double check this.
Drop extra check of platform_get_resource() returned value.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191021103625.4250-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Two spelling mistakes are being fixed.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191023121643.25237-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Intel(R) Programmable Services Engine (Intel(R) PSE) SPI controllers in
Intel Elkhart Lake have two Chip Select signals instead of one.
Reported-by: Raymond Tan <raymond.tan@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20191018132131.31608-3-jarkko.nikula@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Implement pm_runtime hooks at pci driver.
Signed-off-by: Raymond Tan <raymond.tan@intel.com>
[jarkko.nikula@linux.intel.com: Forward ported on top of
commit 1e6959832510 ("spi: dw: Add basic runtime PM support")]
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20191018132131.31608-2-jarkko.nikula@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
After commit 1e6959832510 ("spi: dw: Add basic runtime PM support")
there is following warning from PCI enumerated DesignWare SPI controller
during probe:
dw_spi_pci 0000:00:13.0: Unbalanced pm_runtime_enable!
Runtime PM is already enabled for PCI devices by the PCI core and doing
it again in common DW SPI code leads to unbalanced enable calls.
Fix this by moving the runtime PM enable/disable calls to the platform
driver part of the driver.
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20191018132131.31608-1-jarkko.nikula@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The driver does the wrong thing when cs_change is set on a non-last
xfer in a message. When cs_change is set, the driver deactivates the
CS and leaves it off until a later xfer again has cs_change set whereas
it should be briefly toggling CS off and on again.
This patch brings the behaviour of the driver back in line with the
documentation and common sense. The delay of 10 us is the same as is
used by the default spi_transfer_one_message() function in spi.c.
[gregory: rebased on for-5.5 from spi tree]
Fixes: 8090d6d1a415 ("spi: atmel: Refactor spi-atmel to use SPI framework queue")
Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191018153504.4249-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Thanks to the recent change in this driver, it is now possible to
prevent using the CS0 with GPIO during setup. It then allows to remove
the special handling of this case in the cs_activate() and
cs_deactivate() functions.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-8-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
In the previous implementation of this driver, the index of the GPIO
used as CS was linked to the offset of the CS register used to
configure the transfer.
With this new implementation the first CS register not used by
internal CS is associated to all the GPIO CS. It allows to not be
anymore limited to have only 4 CS managed, now it is possible to have
in the same time until 3 internal CS and no more limit for the CS
GPIO.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-7-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This driver is now only used through the device tree. Simplify code
by explicitly depend on device tree.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-6-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Since the conversion to GPIO descriptor, the GPIO used as chip select,
can be directly access from the spi_device struct. So there is no need
to keep the field npcs_pin.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-5-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
As platform_get_irq_byname() now prints an error when the interrupt
does not exist, scary warnings may be printed for optional interrupts:
renesas_spi e6b10000.spi: IRQ rx not found
renesas_spi e6b10000.spi: IRQ mux not found
Fix this by calling platform_get_irq_byname_optional() instead.
Remove the no longer needed printing of platform_get_irq errors, as the
remaining calls to platform_get_irq() and platform_get_irq_byname() take
care of that.
Fixes: 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20191016143101.28738-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Linux 5.4-rc3
|
|
Instead of setting up the GPIO configuration for the whole controller,
do it at CS level. It will allow to mix internal CS and GPIO CS, which
is not possible with the current implementation.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-4-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Until a few years ago, this driver was only used with CS GPIO. The
only exception is CS0 on AT91RM9200 which has to use internal CS. A
limitation of the internal CS is that they don't support CS High.
So by using the CS GPIO the CS high configuration was available except
for the particular case CS0 on RM9200.
When the support for the internal chip-select was added, the check of
the CS high support was not updated. Due to this the driver accepts
this configuration for all the SPI controller v2 (used by all SoCs
excepting the AT91RM9200) whereas the hardware doesn't support it for
infernal CS.
This patch fixes the test to match the hardware capabilities.
Fixes: 4820303480a1 ("spi: atmel: add support for the internal chip-select of the spi controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-3-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Since CSAAT functionality support has been added. Some comments become
wrong. Fix them to match the current driver behavior.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-2-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
There is nothing in use from of_device.h. The definitions and macros
are available thru mod_devicetable.h and of.h.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191018105429.82782-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Convert to use device_get_match_data() instead of open coded variant.
While here, switch of_property_read_bool() to device_property_read_bool().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191018105429.82782-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This is preparatory patch before converting to use device_get_match_data() API.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191018105429.82782-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Sort the headers in alphabetic order in order to ease the maintenance
for this part.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191018105429.82782-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
There is no need to keep a pointer to the platform device. Currently there are
no users of it directly, and if there will be in the future we may restore it
from pointer to the struct device.
Convert all users at the same time.
Cc: Russell King <linux@armlinux.org.uk>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191018105429.82782-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
When improving the CS GPIO support at core level, the SPI_CS_HIGH
has been enabled for all the CS lines used for a given SPI controller.
However, the SPI framework allows to have on the same controller native
CS and GPIO CS. The native CS may not support the SPI_CS_HIGH, so they
should not be setup automatically.
With this patch the setting is done only for the CS that will use a
GPIO as CS
Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191018152929.3287-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
In DMA mode we have a maximum transfer size, past that the driver
falls back to PIO (see the check at the top of pxa2xx_spi_transfer_one).
Falling back to PIO for big transfers defeats the point of a dma engine,
hence set the max transfer size to inform spi clients that they need
to do something smarter.
This was uncovered by the drm_mipi_dbi spi panel code, which does
large spi transfers, but stopped splitting them after:
commit e143364b4c1774f68e923a5a0bb0fca28ac25888
Author: Noralf Trønnes <noralf@tronnes.org>
Date: Fri Jul 19 17:59:10 2019 +0200
drm/tinydrm: Remove tinydrm_spi_max_transfer_size()
After this commit the code relied on the spi core to split transfers
into max dma-able blocks, which also papered over the PIO fallback issue.
Fix this by setting the overall max transfer size to the DMA limit,
but only when the controller runs in DMA mode.
Fixes: e143364b4c17 ("drm/tinydrm: Remove tinydrm_spi_max_transfer_size()")
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Andy Shevchenko <andriy.shevchenko@intel.com>
Reported-and-tested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20191017064426.30814-1-daniel.vetter@ffwll.ch
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
For many places in the spi drivers, using the new `spi_transfer_delay`
helper is straightforward.
It's just replacing:
```
if (t->delay_usecs)
udelay(t->delay_usecs);
```
with `spi_transfer_delay(t)` which handles both `delay_usecs` and the new
`delay` field.
This change replaces in all places (in the spi drivers) where this change
is simple.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-10-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The AXI SPI engine driver uses the `delay_usecs` field from `spi_transfer`
to configure delays, which the controller will execute.
This change extends the logic to also include the `delay` value, in case it
is used (instead if `delay_usecs`).
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-20-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The driver errors out if `delay_usecs` is non-zero. This error condition
should be extended to the new `delay` field, to account for when it will be
used.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-19-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The WARN_ON macro prints a warning in syslog if `delay_usecs` is non-zero.
However, with the new intermediate `delay`, the warning should also be
printed.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-18-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The way the max delay is computed for this controller, it looks like it is
searching for the max delay from an SPI message a using that.
No idea if this is valid. But this change should support both `delay_usecs`
and the new `delay` data which is of `spi_delay` type.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-17-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This change implements CS control for setup, hold & inactive delays.
The `cs_setup` delay is completely new, and can help with cases where
asserting the CS, also brings the device out of power-sleep, where there
needs to be a longer (than usual), before transferring data.
The `cs_hold` time can overlap with the `delay` (or `delay_usecs`) from an
SPI transfer. The main difference is that `cs_hold` implies that CS will be
de-asserted.
The `cs_inactive` delay does not have a clear use-case yet. It has been
implemented mostly because the `spi_set_cs_timing()` function implements
it. To some degree, this could overlap or replace `cs_change_delay`, but
this will require more consideration/investigation in the future.
All these delays have been added to the `spi_controller` struct, as they
would typically be configured by calling `spi_set_cs_timing()` after an
`spi_setup()` call.
Software-mode for CS control, implies that the `set_cs_timing()` hook has
not been provided for the `spi_controller` object.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-16-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The initial version of `spi_set_cs_timing()` was implemented with
consideration only for clock-cycles as delay.
For cases like `CS setup` time, it's sometimes needed that micro-seconds
(or nano-seconds) are required, or sometimes even longer delays, for cases
where the device needs a little longer to start transferring that after CS
is asserted.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-15-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The `delay` field has type `struct spi_delay`.
This allows users to specify nano-second or clock-cycle delays (if needed).
Converting to use `delay` is straightforward: it's just assigning the
value to `delay.value` and hard-coding the `delay.unit` to
`SPI_DELAY_UNIT_USECS`.
This keeps the uapi for spidev un-changed. Changing it can be part of
another changeset and discussion.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-14-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This change replaces the use of the `delay_usecs` field with the new
`delay` field. The code/test still uses micro-seconds, but they are now
configured and used via the `struct spi_delay` format of the `delay` field.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-13-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This conversion to the spi_transfer_delay_exec() helper is not
straightforward, as it seems that when a delay is present, the controller
issues a command, and then a delay is followed.
This change adds support for the new `delay` field which is of type
`spi_delay` and keeps backwards compatibility with the old `delay_usecs`
field.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-12-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The tegra114 driver has a weird/separate `tegra_spi_transfer_delay()`
function that does 2 delays: one mdelay() and one udelay().
This was introduced via commit f4fade12d506e14867a2b0a5e2f7aaf227297d8b
("spi/tegra114: Correct support for cs_change").
There doesn't seem to be a mention in that commit message to suggest a
specific need/use-case for having the 2 delay calls.
For the most part, udelay() should be sufficient.
This change replaces it with the new `spi_transfer_delay_exec()`, which
should do the same thing.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-11-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The change introduces the `delay` field to the `spi_transfer` struct as an
`struct spi_delay` type.
This intends to eventually replace `delay_usecs`.
But, since there are many users of `delay_usecs`, this needs some
intermediate work.
A helper called `spi_transfer_delay_exec()` is also added, which maintains
backwards compatibility with `delay_usecs`, by assigning the value to
`delay` if non-zero.
This should maintain backwards compatibility with current users of
`udelay_usecs`.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
This change does a conversion from the `word_delay_usecs` -> `word_delay`
for the `spi_device` struct.
This allows users to specify inter-word delays in other unit types
(nano-seconds or clock cycles), depending on how users want.
The Atmel SPI driver is the only current user of the `word_delay_usecs`
field (from the `spi_device` struct).
So, it needed a slight conversion to use the `word_delay` as an `spi_delay`
struct.
In SPI core, the only required mechanism is to update the `word_delay`
information per `spi_transfer`. This requires a bit more logic than before,
because it needs that both delays be converted to a common unit
(nano-seconds) for comparison.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The `word_delay` field had it's type changed to `struct spi_delay`.
This allows users to specify nano-second or clock-cycle delays (if needed).
Converting to use `word_delay` is straightforward: it's just assigning the
value to `word_delay.value` and hard-coding the `word_delay.unit` to
`SPI_DELAY_UNIT_USECS`
This keeps the uapi for spidev un-changed. Changing it can be part of
another changeset and discussion.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-7-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The `word_delay` field had it's type changed to `struct spi_delay`.
This allows users to specify nano-second or clock-cycle delays (if needed).
Converting to use `word_delay` is straightforward: it just uses the new
`spi_delay_exec()` routine, that handles the `unit` part.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-6-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The Spreadtrum SPI driver is the only user of the `word_delay` field in
the `spi_transfer` struct.
This change converts the field to use the `spi_delay` struct. This also
enforces the users to specify the delay unit to be `SPI_DELAY_UNIT_SCK`.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-5-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Since the logic for `spi_delay` struct + `spi_delay_exec()` has been copied
from the `cs_change_delay` logic, it's natural to make this delay, the
first user.
The `cs_change_delay` logic requires that the default remain 10 uS, in case
it is unspecified/unconfigured. So, there is some special handling needed
to do that.
The ADIS library is one of the few users of the new `cs_change_delay`
parameter for an spi_transfer.
The introduction of the `spi_delay` struct, requires that the users of of
`cs_change_delay` get an update. This change also updates the ADIS library.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-4-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
There are plenty of delays that have been introduced in SPI core. Most of
them are in micro-seconds, some need to be in nano-seconds, and some in
clock-cycles.
For some of these delays (related to transfers & CS timing) it may make
sense to have a `spi_delay` struct that abstracts these a bit.
The important element of these delays [for unification] seems to be the
`unit` of the delay.
It looks like micro-seconds is good enough for most people, but every-once
in a while, some delays seem to require other units of measurement.
This change adds the `spi_delay` struct & a `spi_delay_exec()` function
that processes a `spi_delay` object/struct to execute the delay.
It's a copy of the `cs_change_delay` mechanism, but without the default
for 10 uS.
The clock-cycle delay unit is a bit special, as it needs to be bound to an
`spi_transfer` object to execute.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-3-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
The `cs_change_delay` backwards compatibility value could be moved outside
of the switch statement.
The only reason to do it, is to make the next patches easier to diff.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-2-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/spi/spi-npcm-pspi.c: In function npcm_pspi_handler:
drivers/spi/spi-npcm-pspi.c:296:6: warning: variable val set but not used [-Wunused-but-set-variable]
It is not used since commit 2a22f1b30cee ("spi:
npcm: add NPCM PSPI controller driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1570581437-104549-3-git-send-email-zhengbin13@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/spi/spi-omap-100k.c: In function spi100k_read_data:
drivers/spi/spi-omap-100k.c:140:6: warning: variable dataH set but not used [-Wunused-but-set-variable]
It is not used since commit 35c9049b2704 ("Add OMAP spi100k driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1570581437-104549-2-git-send-email-zhengbin13@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.5
|
|
Later versions of the QSPI controller (e.g. in i.MX6UL/ULL and i.MX7)
seem to have an additional TDH setting in the FLSHCR register, that
needs to be set in accordance with the access mode that is used (DDR
or SDR).
Previous bootstages such as BootROM or bootloader might have used the
DDR mode to access the flash. As we currently only use SDR mode, we
need to make sure the TDH bits are cleared upon initialization.
Fixes: 84d043185dbe ("spi: Add a driver for the Freescale/NXP QuadSPI controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Acked-by: Han Xu <han.xu@nxp.com>
Link: https://lore.kernel.org/r/20191007071933.26786-1-frieder.schrempf@kontron.de
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
With this patch, the "interrupts" property from the device tree bindings
is ignored, even if present, if the driver runs in TCFQ mode.
Switching to using the DSPI in poll mode has several distinct
benefits:
- With interrupts, the DSPI driver in TCFQ mode raises an IRQ after each
transmitted word. There is more time wasted for the "waitq" event than
for actual I/O. And the DSPI IRQ count can easily get the largest in
/proc/interrupts on Freescale boards with attached SPI devices.
- The SPI I/O time is both lower, and more consistently so. Attached to
some Freescale devices are either PTP switches, or SPI RTCs. For
reading time off of a SPI slave device, it is important that all SPI
transfers take a deterministic time to complete.
- In poll mode there is much less time spent by the CPU in hardirq
context, which helps with the response latency of the system, and at
the same time there is more control over when interrupts must be
disabled (to get a precise timestamp measurement): win-win.
On the LS1021A-TSN board, where the SPI device is a SJA1105 PTP switch
(with a bits_per_word=8 driver), I created a "benchmark" where I read
its PTP time once per second, for 120 seconds. Each "read PTP time" is a
12-byte SPI transfer. I then recorded the time before putting the first
byte in the TX FIFO, and the time after reading the last byte from the
RX FIFO. That is the transfer delay in nanoseconds.
Interrupt mode:
delay: min 125120 max 168320 mean 150286 std dev 17675.3
Poll mode:
delay: min 69440 max 119040 mean 70312.9 std dev 8065.34
Both the mean latency and the standard deviation are more than 50% lower
in poll mode than in interrupt mode. This is with an 'ondemand' governor
on an otherwise idle system - therefore running mostly at 600 MHz out of
a max of 1200 MHz.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190905010114.26718-5-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
In this mode, the DSPI controller uses PIO to transfer word by word. In
comparison, in EOQ mode the 4-word deep FIFO is being used, hence the
current logic will need some adaptation for which I do not have the
hardware (Coldfire) to test. It is not clear what is the timing of DMA
transfers and whether timestamping in the driver brings any overall
performance increase compared to regular timestamping done in the core.
Short phc2sys summary after 58 minutes of running on LS1021A-TSN with
interrupts disabled during the critical section:
offset: min -26251 max 16416 mean -21.8672 std dev 863.416
delay: min 4720 max 57280 mean 5182.49 std dev 1607.19
lost servo lock 3 times
Summary of the same phc2sys service running for 120 minutes with
interrupts disabled:
offset: min -378 max 381 mean -0.0083089 std dev 101.495
delay: min 4720 max 5920 mean 5129.38 std dev 154.899
lost servo lock 0 times
The minimum delay (pre to post time) in nanoseconds is the same, but the
maximum delay is quite a bit higher, due to interrupts getting sometimes
executed and interfering with the measurement. Hence set disable_irqs
whenever possible (aka when the driver runs in poll mode - otherwise it
would be a contradiction in terms).
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190905010114.26718-4-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
|
