The code used to assert and de-assert a chip select line is very
complicated for no reason. Simplify the logic by either setting or
resetting the concerned bit, which actually only changes an electrical
state.

Update the comment to reflect that there is no possibility to actually
choose a CS as the default (CS0) will be driven in any case.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-6-miquel.raynal@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Using masks makes sense when manipulating fields of several bits. When
only one bit is involved, it is usual to just use the BIT() macro but
in this case using the term mask is abusive. Fix the #define macros
and their comments.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-5-miquel.raynal@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Most of the bits/bitfields #define'd in this driver are composed with:
1/ the driver prefix
2/ the name of the register they apply to

Keep the naming consistent by applying this rule to the CONFIG register
internals. These definitions will be used in a following change set.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-4-miquel.raynal@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Unlike what the driver is currently advertizing, CS0 only can be used,
CS1 is not supported at all. Prevent people to use CS1.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-2-miquel.raynal@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

In this driver (and also in a lot of other drivers in drivers/spi/),
the spi_controller structure is sometimes referred as 'ctlr' and
sometimes as 'ctrl'. Grepping there shows that 'ctlr' seems to be more
common so keep the naming consistent in this driver and s/ctrl/ctlr/.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108105920.19014-3-miquel.raynal@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Devices with chip selects driven via GPIO are not compatible with the
spi-mem operations. Fallback to using standard spi transfers when the
device is connected with a gpio CS.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20191107044235.4864-3-chris.packham@alliedtelesis.co.nzSigned-off-by: Mark Brown <broonie@kernel.org>

Set use_gpio_descriptors to true and avoid asserting the native chip
select if the spi core has done it for us.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20191107044235.4864-2-chris.packham@alliedtelesis.co.nzSigned-off-by: Mark Brown <broonie@kernel.org>

The channels spfi->tx_ch and spfi->rx_ch are not set to NULL after they
are released. As a result, they will be released again, either on the
error handling branch in the same function or in the corresponding
remove function, i.e. img_spfi_remove(). This patch fixes the bug by
setting the two members to NULL.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Link: https://lore.kernel.org/r/1573007769-20131-1-git-send-email-bianpan2016@163.comSigned-off-by: Mark Brown <broonie@kernel.org>

As to set_cs takes effect immediately, power spi
is needed when setup spi.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
Link: https://lore.kernel.org/r/1572426234-30019-1-git-send-email-luhua.xu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

This driver does not use any symbols from the legacy GPIO
header so drop the include.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191030073624.23974-1-linus.walleij@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

The DW driver does not use the legacy GPIO header so drop
it from the spi-dw.h include.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191030073418.23717-1-linus.walleij@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

This converts the TXX9 SPI driver to use GPIO descriptors
to control the GPIO chip selects.

As the driver was clearly (ab)using the device tree "reg"
property to offset into the global GPIO chip we have to
add a hack to counter the hack: add a 1-to-1 chip select
to GPIO offset mapping for all 16 lines on the TXX9 GPIO
chip. The details are described in a largeish comment
in the patch.

We do not need to set up the GPIO as output any more since
the core will take care of this, as well as it will handle
the polarity inversion semantics.

Cc: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191030073832.24038-1-linus.walleij@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Committed version of the commit b9fc2d20 ("spi: dw: Move runtime PM
enable/disable from common to platform driver part") does not include by
some reason changes to drivers/spi/spi-dw.c that were part of the original
patch sent to the mailing list.

Complete the code move by doing those changes now.

Fixes: b9fc2d20 ("spi: dw: Move runtime PM enable/disable from common to platform driver part")
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20191030113137.15459-1-jarkko.nikula@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

When rebooting system, the PMIC watchdog time loading may not be loaded
correctly when another system is feeding the PMIC watchdog, since we did
not check the watchdog busy status before loading time values.

Thus we should set the BIT_WDG_NEW bit before loading time values, that
can support multiple loads without checking busy status to make sure the
time values can be loaded successfully to avoid this potential issue.
Signed-off-by: Lingling Xu <ling_ling.xu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Link: https://lore.kernel.org/r/5655318a7252c9ea518c2f7950a61228ab8f42bf.1572257085.git.baolin.wang@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

When rebooting the system, we should lock the watchdog after
configuration to make sure the watchdog can reboot the system
successfully.
Signed-off-by: Lingling Xu <ling_ling.xu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Link: https://lore.kernel.org/r/7b04711127434555e3a1a86bc6be99860cd86668.1572257085.git.baolin.wang@linaro.orgSigned-off-by: Mark Brown <broonie@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.comSigned-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.comSigned-off-by: Mark Brown <broonie@kernel.org>

This property is used to set the number of bits per transfer (bits_per_word).

Xilinx' IP core allows either 8, 16 or 32, and is non changeable on runtime,
only when instantiating the core.
Signed-off-by: Alvaro Gamez Machado <alvaro.gamez@hazent.com>
Link: https://lore.kernel.org/r/20191024110757.25820-2-alvaro.gamez@hazent.comSigned-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.comSigned-off-by: Mark Brown <broonie@kernel.org>

This change documents the CS setup, host & inactive times. They were
omitted when the fields were added, and were caught by one of the build
bots.

Fixes: 25093bde ("spi: implement SW control for CS times")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20191023070046.12478-1-alexandru.ardelean@analog.comSigned-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.comSigned-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 1e695983 ("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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-off-by: Mark Brown <broonie@kernel.org>

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.comSigned-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: 48203034 ("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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-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.comSigned-off-by: Mark Brown <broonie@kernel.org>