Commit Graph

4231 Commits

Author SHA1 Message Date
Clark Wang
4e3891a55f
spi: lpspi: Code cleanup
Delete the extra space.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:18:13 +00:00
Clark Wang
578465ea2b
spi: lpspi: Add the missing NULL check
The spi_transfer *t will be used in one transfer whatever. If t is NULL,
there has no need to try sending data, so add an error return here.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:59 +00:00
Clark Wang
09c04466ce
spi: lpspi: add dma mode support
Add dma mode support for LPSPI. Any frame longer than half txfifosize will
be sent by dma mode.

For now, there are some limits:
1. The maximum transfer speed in master mode depends on the slave device,
   at least 40MHz(tested by spi-nor on 8qm-lpddr4-arm2 base board);
2. The maximum transfer speed in slave mode is 15MHz(imx7ulp),
   22MHz(8qm/qxp). In order to reach the maximum speed which is mentioned
   in datasheet, the load of connect wires between master and slave
   should be less than 15pF.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:44 +00:00
Clark Wang
c7a4025995
spi: lpspi: use the core way to implement cs-gpio function
Use the default implementation of transfer_one_msg/chipselect/setup
functions in spi core to implement cs-gpio control.
Use fsl_lpspi_prepare_message to init the cs_gpio pin.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:30 +00:00
Clark Wang
77736a98b8
spi: lpspi: add the error info of transfer speed setting
Add a error info when set a speed which greater than half of per-clk of
spi module.

The minimum SCK period is 2 cycles(CCR[SCKDIV]). So the maximum transfer
speed is half of spi per-clk.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:15 +00:00
Han Xu
944c01a889
spi: lpspi: enable runtime pm for lpspi
Enable the runtime power management for lpspi module.

Do some adaptation work from kernel 4.9 to 4.14.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:00 +00:00
Clark Wang
f5e5afdb0e
spi: lpspi: Add i.MX8 boards support for lpspi
Add both ipg and per clock for lpspi to support i.MX8QM/QXP boards.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:16:37 +00:00
Ludovic Barre
2e541b64ee
spi: spi-mem: stm32-qspi: add suspend/resume support
This patch adds suspend and resume support for spi-stm32-qspi
drivers.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 17:14:32 +00:00
Mark Brown
3949ba3b37
Merge branch 'spi-5.1' into spi-5.2 for stm32 2019-03-15 17:06:34 +00:00
Ludovic Barre
5356c2c70e
spi: spi-mem: stm32-qspi: avoid memory corruption at low frequency
This patch solves a memory corruption seen at 8 MHz.
To avoid such issue, timeout counter is disabled.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:33 +00:00
Geert Uytterhoeven
26843bb128
spi: rspi: Fix sequencer reset during initialization
While the sequencer is reset after each SPI message since commit
880c6d114f ("spi: rspi: Add support for Quad and Dual SPI
Transfers on QSPI"), it was never reset for the first message, thus
relying on reset state or bootloader settings.

Fix this by initializing it explicitly during configuration.

Fixes: 0b2182ddac ("spi: add support for Renesas RSPI")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:19 +00:00
Geert Uytterhoeven
42bdaaece1
spi: rspi: Fix register initialization while runtime-suspended
The Renesas RSPI/QSPI driver performs SPI controller register
initialization in its spi_operations.setup() callback, without calling
pm_runtime_get_sync() first, which may cause spurious failures.

So far this went unnoticed, as this SPI controller is typically used
with a single SPI NOR FLASH containing the boot loader:
  1. If the device's module clock is still enabled (left enabled by the
     bootloader, and not yet disabled by the clk_disable_unused() late
     initcall), register initialization succeeds,
  2. If the device's module clock is disabled, register writes don't
     seem to cause lock-ups or crashes.
     Data received in the first SPI message may be corrupted, though.
     Subsequent SPI messages seem to be OK.
     E.g. on r8a7791/koelsch, one bit is lost while receiving the 6th
     byte of the JEDEC ID for the s25fl512s FLASH, corrupting that byte
     and all later bytes.  But until commit a2126b0a01 ("mtd:
     spi-nor: refine Spansion S25FL512S ID"), the 6th byte was not
     considered for FLASH identification.

Fix this by moving all initialization from the .setup() to the
.prepare_message() callback.  The latter is always called after the
device has been runtime-resumed by the SPI core.

This also makes the driver follow the rule that .setup() must not change
global driver state or register values, as that might break a transfer
in progress.

Fixes: 490c97747d ("spi: rspi: Add runtime PM support, using spi core auto_runtime_pm")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:04 +00:00
Volker Haspel
8fcb830a00
spi: spi-fsl-qspi: use devm_spi_register_controller
The driver does not clearly unregister the spi controller.
Therefore calling an unbind and bind again will end up in a
Kernel crash.

The function devm_spi_register_controller will automatically
be unregister the SPI device.

Signed-off-by: Volker Haspel <volker.haspel@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-13 15:18:39 +00:00
Trent Piepho
c842749ea1
spi: imx: stop buffer overflow in RX FIFO flush
Commit 71abd29057 ("spi: imx: Add support for SPI Slave mode") added
an RX FIFO flush before start of a transfer.  In slave mode, the master
may have sent more data than expected and this data will still be in the
RX FIFO at the start of the next transfer, and so needs to be flushed.

However, the code to do the flush was accidentally saving this data into
the previous transfer's RX buffer, clobbering the contents of whatever
followed that buffer.

Change it to empty the FIFO and throw away the data.  Every one of the
RX functions for the different eCSPI versions and modes reads the RX
FIFO data using the same readl() call, so just use that, rather than
using the spi_imx->rx function pointer and making sure all the different
rx functions have a working "throw away" mode.

There is another issue, which affects master mode when switching from
DMA to PIO.  There can be extra data in the RX FIFO which triggers this
flush code, causing memory corruption in the same manner.  I don't know
why this data is unexpectedly in the FIFO.  It's likely there is a
different bug or erratum responsible for that.  But regardless of that,
I think this is proper fix the for bug at hand here.

Fixes: 71abd29057 ("spi: imx: Add support for SPI Slave mode")
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-13 15:16:24 +00:00
Trent Piepho
0a9c8998e7
spi: imx: add module parameter to control DMA use
Add the boolean module parameter "use_dma" to control the use of DMA by
the driver.  There are about two dozen other drivers with a "use_dma"
parameter of some sort.

DMA may allow faster and more efficient transfers than using PIO, but it
also adds overhead for small transfers.

High speed receive operations may be less likely to have issues with
FIFO overflow when using DMA than when using PIO.

The eCSPI appears to insert a 4 bit pause after each word in DMA mode,
not done in PIO mode, which can make DMA transfers 50% slower than PIO.

In some cases DMA may be a net win while in others PIO might be.  It
depends on the application.  So allow DMA to be enabled or disabled at
the driver level.  The default will be to have it enabled when possible.

Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-11 16:49:16 +00:00
Chris Lesiak
5442dcaa0d
spi: Fix zero length xfer bug
This fixes a bug for messages containing both zero length and
unidirectional xfers.

The function spi_map_msg will allocate dummy tx and/or rx buffers
for use with unidirectional transfers when the hardware can only do
a bidirectional transfer.  That dummy buffer will be used in place
of a NULL buffer even when the xfer length is 0.

Then in the function __spi_map_msg, if he hardware can dma,
the zero length xfer will have spi_map_buf called on the dummy
buffer.

Eventually, __sg_alloc_table is called and returns -EINVAL
because nents == 0.

This fix prevents the error by not using the dummy buffer when
the xfer length is zero.

Signed-off-by: Chris Lesiak <chris.lesiak@licor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-11 16:40:00 +00:00
Mark Brown
14dbfb417b
Merge branch 'spi-5.1' into spi-next 2019-03-04 15:32:51 +00:00
Mark Brown
b50c6ac8b6
Merge branch 'spi-5.0' into spi-linus 2019-03-04 15:32:49 +00:00
Geert Uytterhoeven
0e836c3bea
spi: sh-msiof: Restrict bits per word to 8/16/24/32 on R-Car Gen2/3
While the MSIOF variants in older SuperH and SH/R-Mobile SoCs support
bits-per-word values in the full range 8..32, the variants present in
R-Car Gen2 and Gen3 SoCs are restricted to 8, 16, 24, or 32.

Obtain the value from family-specific sh_msiof_chipdata to fix this.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-04 00:02:28 +00:00
Wei Yongjun
daad4d2a0a
spi: sifive: Remove redundant dev_err call in sifive_spi_probe()
There is a error message within devm_ioremap_resource
already, so remove the dev_err call to avoid redundant
error message.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-22 15:17:58 +00:00
Wei Yongjun
049e5feae1
spi: sifive: Remove spi_master_put in sifive_spi_remove()
The call to spi_master_put() in sifive_spi_remove() is redundant since
the master is registered using devm_spi_register_master() and no
reference hold by using spi_master_get() in sifive_spi_remove().

This is detected by Coccinelle semantic patch.

Fixes: 484a9a68d6 ("spi: sifive: Add driver for the SiFive SPI controller")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-22 15:17:43 +00:00
Russell King
b89fefda7d
spi: spi-gpio: fix SPI_CS_HIGH capability
spi-gpio is capable of dealing with active-high chip-selects.
Unfortunately, commit 4b859db2c6 ("spi: spi-gpio: add SPI_3WIRE
support") broke this by setting master->mode_bits, which overrides
the setting in the spi-bitbang code.  Fix this.

[Fixed a trivial conflict with SPI_3WIRE_HIZ support -- broonie]

Fixes: 4b859db2c6 ("spi: spi-gpio: add SPI_3WIRE support")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2019-02-21 19:03:35 +00:00
Mark Brown
bf9f742c38
Merge branch 'for-5.0' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.1 2019-02-20 17:58:18 +00:00
Andy Shevchenko
ef070b4e4a
spi: pxa2xx: Setup maximum supported DMA transfer length
When the commit b6ced294fb

   ("spi: pxa2xx: Switch to SPI core DMA mapping functionality")

switches to SPI core provided DMA helpers, it missed to setup maximum
supported DMA transfer length for the controller and thus users
mistakenly try to send more data than supported with the following
warning:

  ili9341 spi-PRP0001:01: DMA disabled for transfer length 153600 greater than 65536

Setup maximum supported DMA transfer length in order to make users know
the limit.

Fixes: b6ced294fb ("spi: pxa2xx: Switch to SPI core DMA mapping functionality")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2019-02-20 17:14:14 +00:00
Yash Shah
484a9a68d6
spi: sifive: Add driver for the SiFive SPI controller
Add driver for the SiFive SPI controller
on the HiFive Unleashed board.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-19 15:28:53 +00:00
Baolin Wang
5e060c48bc
spi: sprd: Add a prefix for SPI DMA channel macros
Add a prefix for SPI DMA channel macros to avoid namespace conflicts,
and no functional changes.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-13 15:41:01 +00:00
Lanqing Liu
386119bc7b
spi: sprd: spi: sprd: Add DMA mode support
Add DMA mode support for the Spreadtrum SPI controller, and we will enable
SPI interrupt to help to complete the SPI transfer work in DMA mode.

Signed-off-by: Lanqing Liu <lanqing.liu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-13 12:20:59 +00:00
Lanqing Liu
de082d866c
spi: sprd: Add the SPI irq function for the SPI DMA mode
The SPI irq event will use to complete the SPI work in the SPI DMA mode,
so this patch is a preparation for the following DMA mode support.

Moreover the SPI interrupt can be fired when removing the SPI controller,
so we should make sure the SPI controller has stopped the queue in
remove function before freeing the SPI irq.

Signed-off-by: Lanqing Liu <lanqing.liu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-13 12:20:28 +00:00
Felix Fietkau
28f7604f48
spi: use gpio[d]_set_value_cansleep for setting chipselect GPIO
Sleeping is safe inside spi_transfer_one_message, and some
GPIO chips are running on slow busses (such as I2C GPIO
expanders) and need to sleep for setting values.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-12 16:41:11 +00:00
Jonathan Neuschäfer
9b4f84212f
spi: gpio: Advertise support for SPI_CS_HIGH
The spi-gpio driver already handles different chip select polarities,
but so far this was not advertised in master->mode_bits.

This patch fixes mmc_spi on top of spi_gpio, which is useful in some
testing scenarios.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-12 16:41:10 +00:00
Geert Uytterhoeven
35c35fd925
spi: sh-msiof: Replace spi_master by spi_controller
As of commit 8caab75fd2 ('spi: Generalize SPI "master" to
"controller"'), the old master-centric names are compatibility wrappers
for the new controller-centric names.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-08 13:04:32 +00:00
Geert Uytterhoeven
5a0e577fc9
spi: sh-hspi: Replace spi_master by spi_controller
As of commit 8caab75fd2 ('spi: Generalize SPI "master" to
"controller"'), the old master-centric names are compatibility wrappers
for the new controller-centric names.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-08 13:04:19 +00:00
Geert Uytterhoeven
9428a073eb
spi: rspi: Replace spi_master by spi_controller
As of commit 8caab75fd2 ('spi: Generalize SPI "master" to
"controller"'), the old master-centric names are compatibility wrappers
for the new controller-centric names.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-08 13:02:19 +00:00
Tudor Ambarus
2e5c888873
spi: atmel-quadspi: add support for sam9x60 qspi controller
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>
2019-02-06 17:21:00 +00:00
Tudor Ambarus
bd7905e2fe
spi: atmel-quadspi: add support for named peripheral clock
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>
2019-02-06 17:20:59 +00:00
Tudor Ambarus
b456fd18ca
spi: atmel-quadspi: rework transfer macros
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>
2019-02-06 17:20:40 +00:00
Tudor Ambarus
cae417b2a8
spi: atmel-quadspi: switch to SPDX license identifiers
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>
2019-02-06 17:19:22 +00:00
Tudor Ambarus
2aaa8dd093
spi: atmel-quadspi: return appropriate error code
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>
2019-02-06 17:19:14 +00:00
Tudor Ambarus
9ce4c5128b
spi: atmel-quadspi: remove unnecessary cast
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>
2019-02-06 17:19:06 +00:00
Tudor Ambarus
1db6de22b2
spi: atmel-quadspi: fix naming scheme
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>
2019-02-06 17:18:57 +00:00
Tudor Ambarus
18b6f6e176
spi: atmel-quadspi: drop wrappers for iomem accesses
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>
2019-02-06 17:18:49 +00:00
Tudor Ambarus
3ae012e9df
spi: atmel-quadspi: order header files inclusion alphabetically
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>
2019-02-06 17:18:41 +00:00
Tudor Ambarus
9958c8c39e
spi: atmel-quadspi: cache MR value to avoid a write access
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>
2019-02-06 17:16:41 +00:00
Lukasz Majewski
5ce3cc5674
spi: spi-fsl-dspi: Provide support for DSPI slave mode operation (Vybryd vf610)
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>
2019-02-06 16:47:38 +00:00
Jonas Bonn
473a78a7bb
spi-atmel: support inter-word delay
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>
2019-01-30 23:02:11 +00:00
Jonas Bonn
b7bb367afa
spi: support inter-word delay requirement for devices
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>
2019-01-30 23:02:10 +00:00
Uwe Kleine-König
f3fdea3af4
spi: mxs: add tracing to custom .transfer_one_message callback
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>
2019-01-29 15:08:58 +00:00
Yogesh Narayan Gaur
c55d0e8c54
spi: spi-mem: spi-fsl-qspi: typo fix in author name
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>
2019-01-29 12:12:03 +00:00
Vignesh R
673c865efb
spi: ti-qspi: Fix mmap read when more than one CS in use
Commit 4dea6c9b0b ("spi: spi-ti-qspi: add mmap mode read support") has
has got order of parameter wrong when calling regmap_update_bits() to
select CS for mmap access. Mask and value arguments are interchanged.
Code will work on a system with single slave, but fails when more than
one CS is in use. Fix this by correcting the order of parameters when
calling regmap_update_bits().

Fixes: 4dea6c9b0b ("spi: spi-ti-qspi: add mmap mode read support")
Cc: stable@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-29 12:08:03 +00:00
Yogesh Narayan Gaur
ce6f0697eb
spi: spi-mem: spi-nxp-fspi: add module license info
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>
2019-01-29 11:55:41 +00:00