The sam9x60 qspi controller uses 2 clocks, one for the peripheral register
access, the other for the qspi core and phy. Both are mandatory. It uses
different transfer type bits in IFR register. It has dedicated registers
to specify a read or a write instruction: Read Instruction Code Register
(RICR) and Write Instruction Code Register (WICR). ICR/RICR/WICR have
identical fields.
Tested with sst26vf064b jedec,spi-nor flash. Backward compatibility test
done on sama5d2 qspi controller and mx25l25635e jedec,spi-nor flash.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Naming clocks is a good practice. Keep supporting unnamed
peripheral clock, to be backward compatible with old DTs.
While here, rename clk to pclk, to indicate that it is a
peripheral clock.
Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Split the TFRTYP_TRSFR_ bitfields in 2: one bit encoding the
mem/reg transfer type and one bit encoding the direction of
the transfer (read/write).
Remove NOP when setting read transfer type. Remove useless
setting of write transfer type when
op->data.dir == SPI_MEM_DATA_IN && !op->data.nbytes.
QSPI_IFR_TFRTYP_TRSFR_WRITE is specific just to sama5d2 qspi,
rename it to QSPI_IFR_SAMA5D2_WRITE_TRSFR.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Adopt the SPDX license identifiers to ease license compliance
management.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Return -ENOTSUPP when atmel_qspi_find_mode() fails. Propagate
the error in atmel_qspi_exec_op().
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The cast is done implicitly.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Let general names to core drivers.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The wrappers hid that the accesses are relaxed. Drop them.
Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cosmetic change, no functional change.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Set the controller by default in Serial Memory Mode (SMM) at probe.
Cache Mode Register (MR) value to avoid write access when setting
the controller in serial memory mode at exec_op().
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The NXP's Vybryd vf610 can work as a SPI slave device (the CS and clock
signals are provided by master).
It is possible to specify a single device to work in that mode. As we do
use DMA for transferring data, the RX channel must be prepared for
incoming data.
Moreover, in slave mode we just set a subset of control fields in
configuration registers (CTAR0, PUSHR).
For testing the spidev_test program has been used.
Test script for this patch can be found here:
https://github.com/lmajewski/tests-spi/blob/master/tests/spi/spi_tests.sh
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
If the SPI slave requires an inter-word delay, configure the DLYBCT
register accordingly.
Tested on a SAMA5D2 board (derived from SAMA5D2-Xplained reference
board).
Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Mark Brown <broonie@kernel.org>
CC: Alexandre Belloni <alexandre.belloni@bootlin.com>
CC: Ludovic Desroches <ludovic.desroches@microchip.com>
CC: linux-spi@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Some devices are slow and cannot keep up with the SPI bus and therefore
require a short delay between words of the SPI transfer.
The example of this that I'm looking at is a SAMA5D2 with a minimum SPI
clock of 400kHz talking to an AVR-based SPI slave. The AVR cannot put
bytes on the bus fast enough to keep up with the SoC's SPI controller
even at the lowest bus speed.
This patch introduces the ability to specify a required inter-word
delay for SPI devices. It is up to the controller driver to configure
itself accordingly in order to introduce the requested delay.
Note that, for spi_transfer, there is already a field word_delay that
provides similar functionality. This field, however, is specified in
clock cycles (and worse, SPI controller cycles, not SCK cycles); that
makes this value dependent on the master clock instead of the device
clock for which the delay is intended to provide some relief. This
patch leaves this old word_delay in place and provides a time-based
word_delay_us alongside it; the new field fits in the struct padding
so struct size is constant. There is only one in-kernel user of the
word_delay field and presumably that driver could be reworked to use
the time-based value instead.
The time-based delay is limited to 8 bits as these delays are intended
to be short. The SAMA5D2 that I've tested this on limits delays to a
maximum of ~100us, which is already many word-transfer periods even at
the minimum transfer speed supported by the controller.
Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
CC: Mark Brown <broonie@kernel.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Mark Rutland <mark.rutland@arm.com>
CC: linux-spi@vger.kernel.org
CC: devicetree@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Driver specific implementations for .transfer_one_message need to call
the tracing stuff themself. This is necessary to make spi tracing
actually useful.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Typo fix in Author Boris Brezillon last name and update with new
email address.
Fixes: 84d043185d ("spi: Add a driver for the Freescale/NXP QuadSPI controller")
Signed-off-by: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add MODULE_LICENSE info to fix below warning:
WARNING: modpost: missing MODULE_LICENSE() in drivers/spi/spi-nxp-fspi.o
Typo fix in Boris Brezillon last name.
Fixes: a5356aef6a ("spi: spi-mem: Add driver for NXP FlexSPI controller")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
When transfer timeout, give -EAGAIN to the message's status, and it can
make the spi device driver choose repeated transimation or not. And if
transfer timeout, output some useful information for tracing the issue.
Signed-off-by: Jiwei Sun <jiwei.sun@windriver.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The spi-imx driver supports both master and slave modes, so update
the help text to make it more generic.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add octal mode flags for octal I/O data transfer support.
NXP FlexSPI controller supports 8 lines Rx/Tx data transfer.
Signed-off-by: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
- Add driver for NXP FlexSPI host controller
(0) What is the FlexSPI controller?
FlexSPI is a flexsible SPI host controller which supports two SPI
channels and up to 4 external devices. Each channel supports
Single/Dual/Quad/Octal mode data transfer (1/2/4/8 bidirectional
data lines) i.e. FlexSPI acts as an interface to external devices,
maximum 4, each with up to 8 bidirectional data lines.
It uses new SPI memory interface of the SPI framework to issue
flash memory operations to up to four connected flash
devices (2 buses with 2 CS each).
(1) Tested this driver with the mtd_debug and JFFS2 filesystem utility
on NXP LX2160ARDB and LX2160AQDS targets.
LX2160ARDB is having two NOR slave device connected on single bus A
i.e. A0 and A1 (CS0 and CS1).
LX2160AQDS is having two NOR slave device connected on separate buses
one flash on A0 and second on B1 i.e. (CS0 and CS3).
Verified this driver on following SPI NOR flashes:
Micron, mt35xu512ab, [Read - 1 bit mode]
Cypress, s25fl512s, [Read - 1/2/4 bit mode]
Signed-off-by: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Tested-by: Ashish Kumar <Ashish.Kumar@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The Cadence controller also supports platforms specifying
native chipselects. When I enforce the use of high CS
for drivers opting in for using GPIO descriptors, I
inadvertedly switched the driver to also use active
high chip select for native chip selects.
Fix this by inverting the logic in the callback for the
native chip select. Rename the parameter from "is_high"
(which is interpreted as being high when 0, which is
confusing, I will not make any drug-related jokes here)
to "enabled" which is more intuitive, especially now that
it is true when CS is supposed to be enabled.
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Fixes: cfeefa79dc ("spi: cadence: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The DW controller also supports platforms specifying
native chipselects. When I enforce the use of high CS
for drivers opting in for using GPIO descriptors, I
inadvertedly switched the driver to also use active
high chip select for native chip selects.
As it turns out, the DW hardware driving chip selects
also thinks it is weird with active low chip selects
so all we need to do is remove an inversion in the
driver.
Cc: Jan Kotas <jank@cadence.com>
Reported-by: Jan Kotas <jank@cadence.com>
Tested-by: Jan Kotas <jank@cadence.com>
Fixes: 9400c41e77 ("spi: dw: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
All controllers using GPIO descriptors can by definition
support high CS connections, so just enforce this when
registering an SPI controller.
This fixes a regression where controllers were missing
SPI_CS_HIGH, the drivers would fail like this:
spi spi0.0: setup: unsupported mode bits 4
cdns-spi fd0b0000.spi: can't setup spi0.0, status -22
This is because as using descriptors moves the CS inversion
logic over to gpiolib, all such controllers are registered
with CS active high.
Cc: Jan Kotas <jank@cadence.com>
Reported-by: Jan Kotas <jank@cadence.com>
Tested-by: Jan Kotas <jank@cadence.com>
Fixes: f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 412e603732 ("spi: core: avoid waking pump thread from spi_sync
instead run teardown delayed") introduced regressions on some boards,
apparently connected to spi_mem not triggering shutdown properly any
more. Since we've thus far been unable to figure out exactly where the
breakage is revert the optimisation for now.
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: kernel@martin.sperl.org
It's also a slave controller driver now, calling it "master" is slightly
misleading.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix a static code checker warning:
drivers/spi/spi-bcm2835aux.c:460
bcm2835aux_spi_probe() warn: passing zero to 'PTR_ERR'
In case of error, the function devm_clk_get() returns ERR_PTR()
and not returns NULL.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Since direct mapping descriptors usually the same lifetime as the SPI
MEM device adding devm_ variants of the spi_mem_dirmap_{create,destroy}()
should greatly simplify error/remove path of spi-mem drivers making use
of the direct mapping API.
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently, this driver only supports feature for DMA 32-bits.
In this case, only if the data length is divisible by 4 to use
DMA, otherwise PIO will be used. This patch will suggest use
the DMA 32-bits with 4bytes of words, then the remaining data
will be transmitted by PIO mode.
Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
sh_msiof_spi_info *info struct pointer was initialized in the probe() function
no need to get back and keep consistency.
Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
There is no need to print an error message when memory allocations or
related operations fail, as the core will take care of that.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
The custom setup/cleanup routines included in the ath79 driver only
take care of setting the initial CS state. However that is already
handled by the bitbang code, so this code can be removed.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
To allow building this driver in compile test we need to remove all
dependency on headers from arch/mips/include. To allow this we
explicitly define all the registers locally instead of using
ar71xx_regs.h and we move the platform data struct definition to
include/linux/platform_data/spi-ath79.h.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
First of all this callback was slightly misused to setup the clock
polarity at the beginning of a transfer. Beside being at the wrong
place, it is also useless as only SPI mode 1 is supported. Instead
just make sure the base value used for IOC is suitable to start a
transfer by clearing the clock and data bits during the controller
setup.
This also remove the last direct usage of the GPIO API, so we can
remove the direct dependency on GPIOLIB.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
spi_setup() already call spi_set_cs() right after calling the
controller setup method, so there is no need for the bitbang driver to
do that. Because of this the chipselect() callback was confusingly
still called when CS is GPIO based.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently the driver calls pm_runtime_put_autosuspend but without ever
having done a pm_runtime_get, this causes the reference count in the pm
runtime core to become -1. The bad reference count causes the core to
sometimes suspend whilst an active SPI transfer is in progress.
arizona spi0.1: SPI transfer timed out
spi_master spi0: failed to transfer one message from queue
The correct proceedure is to do all the initialisation that requires the
hardware to be powered up before enabling the PM runtime, then enable
the PM runtime having called pm_runtime_set_active to inform it that the
hardware is currently powered up. The core will then power it down at
it's leisure and no explicit pm_runtime_put is required.
Fixes: d36ccd9f7e ("spi: cadence: Runtime pm adaptation")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
We don't need this forward declaration. Move the function to where it
needed so we can drop it and shave some lines of code.
CC: Girish Mahadevan <girishm@codeaurora.org>
CC: Dilip Kota <dkota@codeaurora.org>
CC: Alok Chauhan <alokc@codeaurora.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
We only use this completion when we're doing something that isn't a
message transfer. For example, changing CS or aborting/canceling a
command. All of those situations properly reinitialize the completion
before sending the GENI the special command to change CS or cancel, etc.
Given that, let's remove the initialization here.
Cc: Girish Mahadevan <girishm@codeaurora.org>
Cc: Dilip Kota <dkota@codeaurora.org>
Cc: Alok Chauhan <alokc@codeaurora.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The previous commit left a variable unused, my bad.
Clean it up.
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Lechner <david@lechnology.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 101a68e74f ("spi: davinci: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
When CONFIG_SPI_DESIGNWARE are enabled we see the unused variable
warning in dw_spi_setup.
../drivers/spi/spi-dw.c: In function ‘dw_spi_setup’:
../drivers/spi/spi-dw.c:400:6: warning: unused variable ‘ret’ [-Wunused-variable]
int ret;
^~~
Remove the unused varable.
Fixes: 9400c41e77 ("spi: dw: Convert to use CS GPIO descriptors")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the DesignWare (dw) SPI master driver to
use GPIO descriptors for chip select handling.
This driver has a duplicate DT parser in addition to the
one in the core, sets up the line as non-asserted and
relies on the core to drive the GPIOs.
It is a pretty straight-forward conversion.
Cc: Talel Shenhar <talel@amazon.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Linuxarm <linuxarm@huawei.com>
Tested-by: Jay Fang <f.fangjian@huawei.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the DaVinci SPI master driver to use GPIO
descriptors for chip select handling.
DaVinci parses the device tree a second time for the chip
select GPIOs (no relying on the parsing already happening
in the SPI core) and handles inversion semantics locally.
We simply drop the extra parsing and set up and move the
CS handling to the core and gpiolib. The fact that the
driver is actively driving the GPIO in the
davinci_spi_chipselect() callback is confusing since the
host does not set SPI_MASTER_GPIO_SS so this should not
ever get called when using GPIO CS. I put in a comment
about this.
This driver also supports instantiation from board files,
but these are all using native chip selects so no problem
with GPIO lines here.
Cc: David Lechner <david@lechnology.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the CLPS711x SPI master driver to use GPIO
descriptors for chip select handling.
The CLPS711x driver was merely requesting the GPIO and
setting the CS line non-asserted so this was a pretty
straight-forward conversion. The setup callback goes away.
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the Cadence SPI master driver to use GPIO
descriptors for chip select handling.
The Cadence driver was allocating a state container just
to hold the requested GPIO line and contained lots of
polarity inversion code. As this is all handled by gpiolib
and a simple devm_* request in the core, and as the driver
is fully device tree only, most of this code chunk goes
away in favour of central handling. The setup/cleanup
callbacks goes away.
This driver does NOT drive the CS line by setting the
value of the GPIO so it relies on the SPI core to do
this, which should work just fine with the descriptors.
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Janek Kotas <jank@cadence.com>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the Atmel SPI master driver to use GPIO descriptors
for chip select handling.
The Atmel driver has duplicate code to look up and initialize CS
GPIOs from the device tree, so this is removed. It further has code
to retrieve a CS GPIO from .controller_data but this seems to be
completely unused in the kernel (legacy codepath?) so I deleted
this support. It keeps track of polarity when switching the CS, but
this is not needed anymore since we moved this over to the gpiolib.
The local handling of the "npcs_pin" (I guess this might mean
"negative polarity chip select pin") is preserved, but I strongly
suspect this can be switched over to handling by the core and
using the SPI_MASTER_GPIO_SS flag on the master to assure that
the additional CS handling in the driver is also done.
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Radu Pirea <radu.pirea@microchip.com>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This converts the ATH79 SPI master driver to use GPIO descriptors
for chip select handling.
The ATH79 driver was requesting the GPIO and driving it from the
bitbang .chipselect callback. Do not request it anymore as the SPI
core will request it, remove the line inversion semantics for the
GPIO case (handled by gpiolib) and let the SPI core deal with
requesting the GPIO line from the device tree node of the controller.
This driver can be instantiated from a board file (no device tree)
but the board files only use native CS (no GPIO lines) so we should
be fine just letting the SPI core grab the GPIO from the device.
The fact that the driver is actively driving the GPIO in the
ath79_spi_chipselect() callback is confusing since the host does
not set SPI_MASTER_GPIO_SS so this should not ever get called when
using GPIO CS. I put in a comment about this.
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Alban Bedel <albeu@free.fr>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This augments the SPI core to optionally use GPIO descriptors
for chip select on a per-master-driver opt-in basis.
Drivers using this will rely on the SPI core to look up
GPIO descriptors associated with the device, such as
when using device tree or board files with GPIO descriptor
tables.
When getting descriptors from the device tree, this will in
turn activate the code in gpiolib that was
added in commit 6953c57ab1
("gpio: of: Handle SPI chipselect legacy bindings")
which means that these descriptors are aware of the active
low semantics that is the default for SPI CS GPIO lines
and we can assume that all of these are "active high" and
thus assign SPI_CS_HIGH to all CS lines on the DT path.
The previously used gpio_set_value() would call down into
gpiod_set_raw_value() and ignore the polarity inversion
semantics.
It seems like many drivers go to great lengths to set up the
CS GPIO line as non-asserted, respecting SPI_CS_HIGH. We pull
this out of the SPI drivers and into the core, and by simply
requesting the line as GPIOD_OUT_LOW when retrieveing it from
the device and relying on the gpiolib to handle any inversion
semantics. This way a lot of code can be simplified and
removed in each converted driver.
The end goal after dealing with each driver in turn, is to
delete the non-descriptor path (of_spi_register_master() for
example) and let the core deal with only descriptors.
The different SPI drivers have complex interactions with the
core so we cannot simply change them all over, we need to use
a stepwise, bisectable approach so that each driver can be
converted and fixed in isolation.
This patch has the intended side effect of adding support for
ACPI GPIOs as it starts relying on gpiod_get_*() to get
the GPIO handle associated with the device.
Cc: Linuxarm <linuxarm@huawei.com>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Fangjian (Turing) <f.fangjian@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add routines, registers & bitfield definition. Also baud rate divisor
definitions for STM32F4 SPI. This version supports full-duplex,
simplex TX and half-duplex TX communication with 8 or 16-bit per word.
DMA capability is optionally supported for transfer longer than 16 bytes.
For transfer less than 16 bytes frames can be send in discontinuous mode.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Prepare support for STM32F4 spi variant by introducing compatible
configuration data.
Move STM32H7 specific stuff to compatible data structure:
- registers & bit fields
- routines to control driver
- baud rate divisor definitions
- fifo availability
- split IRQ functions to parts to be called when the IRQ occurs
and for threaded interrupt what helps to provide less discontinuous
mode for drivers without FIFO.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add transfer_one_dma_start function to be more generic for other
stm32 SPI family drivers.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
