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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 6953c57ab172
("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>
We already need to zero out memory for dma_alloc_coherent(), as such
using dma_zalloc_coherent() is superflous. Phase it out.
This change was generated with the following Coccinelle SmPL patch:
@ replace_dma_zalloc_coherent @
expression dev, size, data, handle, flags;
@@
-dma_zalloc_coherent(dev, size, handle, flags)
+dma_alloc_coherent(dev, size, handle, flags)
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
[hch: re-ran the script on the latest tree]
Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Split stm32_spi_transfer_one_setup function into smaller chunks
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>
Interrupt function is used as a thread so rename it to express
meaning directly by more clear function name.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Rename STM32 SPI registers to be related to STM32H7 SPI driver
and not STM32 generally.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This driver does not support SPI LOOP mode by configuration
in registers.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Driver supports SPI mode 0 to 3 not only the mode 3.
Use SPI_CPOL and SPI_CPHA indicates that these bits
can be changed to obtain modes 0 - 3.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix typo from STMicroelectonics to STMicroelectronics.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
When SPI driver is configured to work only with TX or RX DMA channel
then dmaengine functions can dereferene NULL pointer.
Running full-duplex mode when when only RX or TX DMA channel is
available can cause overrun condition or incorrect writing to transmit
buffer so disable this types of DMA configuration and go back to
interrupt mode.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Patch fixes sparse warning: Using plain integer as NULL pointer. Replaces
second argument of function devm_clk_get from 0 to NULL.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
spi::mode is defined by framework for several SPI capabilities,
such as polarity, phase, bit-endian, wire number. Directly use this
variable for setting controller's polarity and phase causes other
bit in register being set. Since SPI framework has its definition,
SPI_CPOL and SPI_CPHA offset may be changed by framwork change.
Instead of just mask off the relevant bits,
fetch required bit in spi::mode and set to register.
Signed-off-by: shaftarger <shol@livemail.tw>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add some cpu families that are actually using the fsl-dspi module
in the related Kconfig description.
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Mark Brown <broonie@kernel.org>
On ColdFire mcf54418, using DSPI_DMA_MODE mode, spi transfers
at first boot stage are not succeding:
m25p80 spi0.1: unrecognized JEDEC id bytes: 00, 00, 00
The reason is the SPI_SR initial value set by the driver, that
is not clearing (not setting to 1) the RF_DF flag. After a tour
on the dspi hw modules that use this driver(Vybrid, ColdFire and
ls1021a) a better init value for SR register has been set.
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Mark Brown <broonie@kernel.org>
This driver is derived from the SPI NOR driver at
mtd/spi-nor/fsl-quadspi.c. It uses the new SPI memory interface
of the SPI framework to issue flash memory operations to up to
four connected flash chips (2 buses with 2 CS each).
The controller does not support generic SPI messages.
This patch also disables the build of the "old" driver and reuses
its Kconfig option CONFIG_SPI_FSL_QUADSPI to replace it.
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Acked-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Tested-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Tested-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove Reset operation in fsl_lpspi_config(). This RST may cause both CLK
and CS pins go from high to low level under cs-gpio mode.
Add fsl_lpspi_reset() function after one message transfer to clear all
flags in use.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add judgment on SR_MBF and FSR_RXCOUNT.
In PIO mode, if don't use CONT to keep cs selected in one transfer, the
transfer will go wrong. FCIE will be set after one frame transfer
finish. If use CONT, the frame refer to the whole data in one transfer.
If don't use CONT, the frame refer to one byte of whole data. This will
cause the transfer ending early.
This patch add a register reading in isr function, it might lead to a
slight decrease in the max transmission speed in PIO mode.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use SR_TDF to judge if need to send data, and SR_FCF is to judge if
transmission end and to replace the waiting after transmission end.
This waiting has no actual meaning, for module will set the FCF
flag at the real end.
The changes of interrupt flag and ISR function reduce the times of
calling ISR. The use of the FCF flag improves the stability of the
data transmission. These two points generally improve the data
transfer speed of lpspi, especially when it is set to slave mode
it can support higher transfer speed of the host.
After making these changes, there is no need to use
fsl_lpspi_txfifo_empty(), so remove it.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In npcm_pspi_probe(), current code set platform_set_drvdata(pdev, master);
so in npcm_pspi_remove() platform_get_drvdata(pdev) will return pointer to
master rather than priv. Fix it.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The main thing this release has been a lot of work on the integration
with SPI NOR flashes, there's been some specific support for a while for
controller features designed to make them perform better but it's not
worked out as well as hoped so the interface has been redesigned in a
way that will hopefully do better - it's already been adopted by a
number of additional controllers so things are looking good. Otherwise
most of the work has been driver specific:
- Support for better integration with NOR flashes from Boris Brezillon
and Yogesh Narayan Gaur plus usage of it in several drivers.
- A big cleanup of the Rockchip driver from Emil Renner Berthing.
- Lots of performance improvements for bcm2835 from Lukas Wunner.
- Slave mode support for pxa2xx from Lubomir Rintel.
- Support for Macronix MXIC, Mediatek MT7629 and MT8183, NPCM PSPI,
and Renesas r8a77470.
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Merge tag 'spi-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown:
"The main thing this release has been a lot of work on the integration
with SPI NOR flashes, there's been some specific support for a while
for controller features designed to make them perform better but it's
not worked out as well as hoped so the interface has been redesigned
in a way that will hopefully do better - it's already been adopted by
a number of additional controllers so things are looking good.
Otherwise most of the work has been driver specific:
- Support for better integration with NOR flashes from Boris
Brezillon and Yogesh Narayan Gaur plus usage of it in several
drivers.
- A big cleanup of the Rockchip driver from Emil Renner Berthing.
- Lots of performance improvements for bcm2835 from Lukas Wunner.
- Slave mode support for pxa2xx from Lubomir Rintel.
- Support for Macronix MXIC, Mediatek MT7629 and MT8183, NPCM PSPI,
and Renesas r8a77470"
* tag 'spi-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (90 commits)
spi: sh-msiof: Reduce the number of times write to and perform the transmission from FIFO
spi: sh-msiof: Add r8a774c0 support
doc: lpspi: Document DT bindings for LPSPI slave mode
spi: lpspi: Let watermark change with send data length
spi: lpspi: Add slave mode support
spi: lpspi: Replace all "master" with "controller"
spi: imx: drop useless member speed_hz from driver data struct
spi: imx: rename config callback and add useful parameters
spi: imx: style fixes
spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook.
spi: imx: add a device specific prepare_message callback
mtd: atmel-quadspi: disallow building on ebsa110
spi: Update NPCM PSPI controller documentation
spi: npcm: Modify pspi send function
spi: Use of_node_name_eq for node name comparisons
spi: dw-mmio: add ACPI support
spi: bcm2835: Synchronize with callback on DMA termination
spi: bcm2835: Speed up FIFO access if fill level is known
spi: bcm2835: Polish transfer of DMA prologue
spi: spi-mem: add support for octal mode I/O data transfer
...
The current state of the spi-sh-msiof, in master transfer mode: if t-> bits_per_word <= 8,
if the data length is divisible by 4 ((len & 3) = 0), the length of each word will be 32 bits
In case of data length can not be divisible by 4 ((len & 3) != 0), always set each word to be
8 bits, this will increase the number of times that write to FIFO, increasing the number of
times it should be transmitted. Assume that the number of bytes of data length more than 64 bytes,
each transmission will write 64 times into the TFDR then transmit, a maximum one-time
transmission will transmit 64 bytes if each word is 8 bits long.
Switch to setting if t->bits_per_word <= 8, the word length will be 32 bits although the data
length is not divisible by 4, then if leftover, will transmit the balance and the length of each
words is 1 byte. The maximum each can transmit up to 64 x 4 (Data Size = 32 bits (4 bytes)) = 256 bytes.
TMDR2 : Bits 28 to 24 BITLEN1[4:0] Data Size (8 to 32 bits)
Bits 23 to 16 WDLEN1[7:0] Word Count (1 to 64 words)
Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
Configure watermark to change with the length of the sent data.
Support LPSPI sending message shorter than tx/rxfifosize.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add slave mode support to the fsl-lpspi driver, only in PIO mode.
For now, there are some limitations for slave mode transmission:
1. The stale data in RXFIFO will be dropped when the Slave does any new
transfer.
2. One transfer can be finished only after all transfer->len data been
transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than
this from master device will be dropped. Any data shorter than this
from master will cause LPSPI to stuck due to mentioned limitation 2.
4. Only PIO transfer is supported in Slave Mode.
Wire connection:
GND, SCK, MISO(to MISO of slave), MOSI(to MOSI of slave), SCS
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In order to enable the slave mode and make the code more readable,
replace all related structure names and object names which is
named "master" with "controller".
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The driver data's member variable just caches the transfer's speed_hz
member. All users of the former now have access directly to the latter.
So fix them to use the uncached value and remove the cache.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
The config callback is called once per transfer while some things can (and
should) be done on a per message manner. To have unambiguous naming in the
end include "transfer" in the callback's name and rename the
implementations accordingly. Also pass the driver struct and transfer
which allows further simplifications in the following patch.
There is no change in behavior intended here.
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This change fixes some random style issues that I noticed while debugging
the driver: Remove some double spaces, use tabs for indention instead
of spaces if possible, fix comment style.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
The relevant difference between prepare_message and config is that the
former is run before the CS signal is asserted. So the polarity of the
CLK line must be configured in prepare_message as an edge generated by
config might already result in a latch of the MOSI line.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This is just preparatory work which allows to move some initialisation
that currently is done in the per transfer hook .config to an earlier
point in time in the next few patches. There is no change in behaviour
introduced by this patch.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
I ran into a link-time error with the atmel-quadspi driver on the
EBSA110 platform:
drivers/mtd/built-in.o: In function `atmel_qspi_run_command':
:(.text+0x1ee3c): undefined reference to `_memcpy_toio'
:(.text+0x1ee48): undefined reference to `_memcpy_fromio'
The problem is that _memcpy_toio/_memcpy_fromio are not available on
that platform, and we have to prevent building the driver there.
In case we want to backport this to older kernels: between linux-4.8
and linux-4.20, the Kconfig entry was in drivers/mtd/spi-nor/Kconfig
but had the same problem.
Link: https://lore.kernel.org/patchwork/patch/812860/
Fixes: 161aaab8a067 ("mtd: atmel-quadspi: add driver for Atmel QSPI controller")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Align pspi send function code with the recieve function
code, Also simplify the code a bit with early return.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The Hisilicon Hip08 platform, that uses ACPI, has this controller.
Let's add ACPI support for DW SPI MMIO-based host.
The ACPI ID used is "HISI0173" for the Designware SPI controller of
Hisilicon Hip08 platform.
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit b36f09c3c441 ("dmaengine: Add transfer termination
synchronization support") deprecated dmaengine_terminate_all() in favor
of dmaengine_terminate_sync() and dmaengine_terminate_async() to avoid
freeing resources used by the DMA callback before its execution has
concluded.
Commit de92436ac40f ("dmaengine: bcm2835-dma: Use vchan_terminate_vdesc()
instead of desc_free") amended the BCM2835 DMA driver with an
implementation of ->device_synchronize(), which is a prerequisite for
dmaengine_terminate_sync(). Thus, clients of the DMA driver (such as
the BCM2835 SPI driver) may now be converted to the new API.
It is generally desirable to use the _sync() variant except in atomic
context. There is only a single occurrence where the BCM2835 SPI driver
calls dmaengine_terminate_all() in atomic context and that is in
bcm2835_spi_dma_done() (the RX DMA channel's callback) to terminate the
TX DMA channel. The TX DMA channel doesn't have a callback (yet), hence
it is safe to use the _async() variant there.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The RX and TX FIFO of the BCM2835 SPI master each accommodate 64 bytes
(16 32-bit dwords). The CS register provides hints on their fill level:
"Bit 19 RXR - RX FIFO needs Reading ([¾] full)
0 = RX FIFO is less than [¾] full (or not active TA = 0).
1 = RX FIFO is [¾] or more full. Cleared by reading sufficient
data from the RX FIFO or setting TA to 0."
"Bit 16 DONE - Transfer Done
0 = Transfer is in progress (or not active TA = 0).
1 = Transfer is complete. Cleared by writing more data to the
TX FIFO or setting TA to 0."
"If DONE is set [...], write up to 16 [dwords] to SPI_FIFO. [...]
If RXR is set read 12 [dwords] data from SPI_FIFO."
[Source: Pages 153, 154 and 158 of
https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
Note: The spec is missing the "¾" character, presumably due to
copy-pasting from a different charset. It also incorrectly
refers to 16 and 12 "bytes" instead of 32-bit dwords.]
In short, the RXR bit indicates that 48 bytes can be read and the DONE
bit indicates 64 bytes can be written. Leverage this knowledge to read
or write bytes blindly to the FIFO, without polling whether data can be
read or free space is available to write. Moreover, when a transfer is
starting, the TX FIFO is known to be empty, likewise allowing a blind
write of 64 bytes.
This cuts the number of bus accesses in half if the fill level is known.
Also, the (posted) write accesses can be pipelined on the AXI bus since
they are no longer interleaved with (non-posted) reads.
bcm2835_spi_transfer_one_poll() switches to interrupt mode when a time
limit is exceeded by calling bcm2835_spi_transfer_one_irq(). The TX
FIFO may contain data in this case, but is known to be empty when the
function is called from bcm2835_spi_transfer_one(). Hence only blindly
fill the TX FIFO in the latter case but not the former.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Eric Anholt <eric@anholt.net>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 3bd7f6589f67 ("spi: bcm2835: Overcome sglist entry length
limitation") was unfortunately merged even though submission of a
refined version was imminent. Apply those refinements as an amendment:
* Drop no longer needed #include <asm/page.h>. The lines requiring
its inclusion were removed by the commit.
* Change type of tx_spillover flag from bool to unsigned int for
consistency with dma_pending flag and pursuant to Linus' dictum:
https://lkml.org/lkml/2017/11/21/384
* In bcm2835_rd_fifo_count() do not check for bs->rx_buf != NULL.
The function will never be called if that's the case.
* Amend kerneldoc of bcm2835_wait_tx_fifo_empty() to prevent its use in
situations where the function might spin forever. (In response to a
review comment by Stefan Wahren.)
* Sync only the cacheline containing the RX prologue back to memory,
not the full first sglist entry.
* Use sg_dma_address() and sg_dma_len() instead of referencing the
sglist entry members directly. Seems to be the more common syntax in
the tree, even for lvalues.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add support for octal mode I/O data transfer in spi-mem framework.
Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add flags for Octal mode I/O data transfer
Required for the SPI controller which can do the data transfer (TX/RX)
on 8 data lines e.g. NXP FlexSPI controller.
SPI_TX_OCTAL: transmit with 8 wires
SPI_RX_OCTAL: receive with 8 wires
Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix build errors when CONFIG_PINCTRL is not enabled.
The header file <linux/pinctrl/consumer.h> handles both CONFIG_PINCTRL
enabled and disabled cases.
CC [M] drivers/spi/spi-at91-usart.o
../drivers/spi/spi-at91-usart.c: In function 'at91_usart_spi_runtime_suspend':
../drivers/spi/spi-at91-usart.c:409:2: error: implicit declaration of function 'pinctrl_pm_select_sleep_state' [-Werror=implicit-function-declaration]
pinctrl_pm_select_sleep_state(dev);
../drivers/spi/spi-at91-usart.c: In function 'at91_usart_spi_runtime_resume':
../drivers/spi/spi-at91-usart.c:419:2: error: implicit declaration of function 'pinctrl_pm_select_default_state' [-Werror=implicit-function-declaration]
pinctrl_pm_select_default_state(dev);
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Radu Pirea <radu.pirea@microchip.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
