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>
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>
spi_controller_{suspend,resume}() already prints an error message on
failure, so there is no need to repeat this in individual drivers.
Note: spi_master_{suspend,resume}() is an alias for
spi_controller_{suspend,resume}().
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Daniel Mack <daniel@zonque.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use enum dma_transfer_direction as required by the functions
dmaengine_prep_slave_(sg|single)() instead of enum dma_data_direction.
This won't change behavior in practice as the enum values are
equivalent.
This fixes two warnings when building with clang:
drivers/spi/spi-atmel.c:771:12: warning: implicit conversion from enumeration
type 'enum dma_data_direction' to different enumeration type
'enum dma_transfer_direction'
[-Wenum-conversion]
DMA_FROM_DEVICE,
^~~~~~~~~~~~~~~
...
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
The datasheet recommends initializing FIFOs before
SPI enable. If we do not do it like this, there may be
a strange behavior. We noticed that DMA does not work properly
with FIFOs if we do not clear them beforehand or enable them
before SPIEN.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
This patch enables SPI DMA transfers for Atmel SAM9 SoCs and implements a
bounce buffer for transfers which have vmalloc allocated buffers. Those
buffers are not cache coherent even if they have been transformed into sg
lists. UBIFS is affected by this cache coherency issue.
In this patch I also reverted "spi: atmel: fix corrupted data issue on SAM9
family SoCs"(7094576ccd).
Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The only part of atmel_spi_remove which needs to be atomic is hardware
reset.
atmel_spi_stop_dma calls dma_terminate_all and this needs interrupts
enabled.
atmel_spi_release_dma calls dma_release_channel and dma_release_channel
locks a mutex inside of spin_lock.
So the call of these functions can't be inside a spin_lock.
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch disables the use of the DMA for data transfer and forces the
use of PIO transfers instead as a quick fixup to solve the cache aliasing
issue on ARM9 based cores, which embeds a VIVT data cache.
Indeed in the case of VIVT data caches, it is not safe to call dma_map_*()
functions to map buffers for DMA transfers when those buffers have been
allocated by vmalloc() or from any DMA-unsafe area.
Further patches may propose a better solution based on the use of a bounce
buffer at the SPI sub-system level but such solution needs more time to be
discussed. Then the use of DMA transfers could be enabled again to improve
the performances but before that, this patch already solves the issue.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Don't print the version at the beginning of atmel_spi_probe(). This avoids
spamming the log whenever a deferred probe runs.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This adds deepest (Backup+Self-Refresh) PM support to the ATMEL SAMA5D2
SoC's SPI controller.
When resuming from deepest state, it is required to restore MR register
as the registers are lost since VDD core has been shut down when
entering deepest state on the SAMA5D2.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPI controller configuration during the init can be reused, for the
resume function for example.
Let's move this configuration to a separate function.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
For DMA transfers, we now use the core DMA framework which provides
channel fields in the spi_master structure. Remove the private channels
from atmel_spi stucture which were located in a sub-structure. This
last one (atmel_spi_dma) which is now empty is also removed.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The atmel_spi_dma structure was cluttered with unused fields relative
to older DMA channel selection API. Remove them.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the SPI core DMA mapping framework instead of our own
in case of DMA support. PDC support is not converted to this
framework.
The driver is now able to transfer a complete sg list through DMA.
This eventually fix an issue with vmalloc'ed DMA memory that is
provided for example by UBI/UBIFS layers.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[nicolas.ferre@atmel.com: restrict the use to non-PDC DMA]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
We need both RX and TX data for each transfer in any case (PIO, PDC, DMA).
So convert the driver to the core dummy buffer handling with the
SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure.
This move changes the maximum PDC/DMA buffer handling to 65535 bytes
instead of a single page and sets master->max_dma_len to this value.
All dummy buffer management is removed from the driver.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The info banner is here to tell that everything went well, so place
it at the very end of the probe function.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
A call to clk_get_rate appears to be called in the context of an interrupt,
cache the bus clock for the frequency calculations in transmission.
This fixes a 'BUG: scheduling while atomic' and
'WARNING: CPU: 0 PID: 777 at kernel/sched/core.c:2960 atmel_spi_unlock'
Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Steve deRosier <steve.derosier@lairdtech.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
These lines were indented one extra tab.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the managed gpio CS pin request so that we avoid having trouble
in the cleanup code.
In fact, if module was configured with DT, cleanup code released
invalid pin. Since resource wasn't freed, module cannot be reinserted.
This require to extract the gpio request call from the "setup" function
and call it in the appropriate probe function.
Reported-by: Alexander Morozov <linux@meltdown.ru>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The non-DT platform that uses this driver (actually the AVR32) was taking a bad
branch for determining if the IP would use gpio for CS.
Adding the presence of DT as a condition fixes this issue.
Fixes: 4820303480 ("spi: atmel: add support for the internal chip-select of the spi controller")
Reported-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[nicolas.ferre@atmel.com: extract from ml discussion]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
The DMA-slave configuration depends on the whether <= 8 or > 8 bits
are transferred per word, so we need to call
atmel_spi_dma_slave_config() with the correct value.
Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
SPI core validates both bits_per_word and speed_hz transfer parameters and
defaults to spi->bits_per_word and spi->max_speed_hz in case these per
transfer parameters are not set. This makes possible to remove two if
statements and remove one code block that is never executed.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
When CONFIG_PM is defined but not CONFIG_PM_SLEEP (this happens when
CONFIG_SUSPEND is not defined), there is the following warning:
drivers/spi/spi-atmel.c:1723:12: warning: ‘atmel_spi_suspend’ defined but not used [-Wunused-function]
drivers/spi/spi-atmel.c:1741:12: warning: ‘atmel_spi_resume’ defined but not used [-Wunused-function]
Enclose both atmel_spi_suspend and atmel_spi_resume in #ifdef
CONFIG_PM_SLEEP/#endif to solve that.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Definitions from linux/platform_data/atmel.h are not used, remove the
include.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The latest SPI controllers embedded inside sama5d2x SoCs come with FIFOs.
When FIFOs are enabled, they can either work in SINGLE data mode or
MULTIPLE data mode. The selected mode depends on the configuration of the
SPI controller (see below).
In SINGLE data mode (or legacy mode), for a single I/O access, only one
data can be read from the Receive Data Register (RDR) or written into the
Transmit Data Register (TDR). On the other hand, in MULTIPLE data mode, up
to 4 data can be read from the RDR or up 2 data can be written into the
TDR in a single 32bit I/O access. So programmers should take good care of
the width of the I/O access to read/write the right number of data. The
exact number of read/written data depends on both the I/O access width and
the data width (from 8 up to 16 bits).
To enable the FIFO feature a "atmel,fifo-size" property must be set to
provide the maximum number of data (not bytes) the RX and TX FIFOs can
store. Hence a 32 data FIFO can always store up to 32 data unrelated with
the actual data width.
When FIFOs are enabled, the RX one is forced to operate in SINGLE data
mode because this driver configures the spi controller as a master. In
master mode only, the Received Data Register has an additionnal Peripheral
Chip Select field, which prevents us from reading more than a single data
at each register access.
Besides, the TX FIFO operates in MULTIPLE data mode. However, even when a
8bit data size is used, only two data by access could be written into the
Transmit Data Register. Indeed the first data has to be written into the
lowest 16 bits whereas the second data has to be written into the highest
16 bits of the TDR. When DMA transfers are used to send data, we don't
rework the transmit buffer to cope with this hardware limitation: the
additional copies required to prepare a new input buffer suited to both
the DMA controller and the spi controller would waste all the benefit of
the DMA transfer. Instead, the DMA controller is configured to write only
one data at time into the TDR.
In pio mode, two data are written in the TDR in a single access.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch relies on the CSAAT (Chip Select Active After Transfer) feature
introduced by the version 2 of the spi controller. This new mode allows to
use properly the internal chip-select output pin of the spi controller
instead of using external gpios. Consequently, the "cs-gpios" device-tree
property becomes optional.
When the new CSAAT bit is set into the Chip Select Register, the internal
chip-select output pin remains asserted till both the following conditions
become true:
- the LASTXFER bit is set into the Control Register (or the Transmit Data
Register)
- the Transmit Data Register and its shift register are empty.
WARNING: if the LASTXFER bit is set into the Control Register then new
data are written into the Transmit Data Register fast enough to keep its
shifter not empty, the chip-select output pin remains asserted. Only when
the shifter becomes empty, the chip-select output pin is unasserted.
When the CSAAT bit is clear in the Chip Select Register, the LASTXFER bit
is ignored in both the Control Register and the Transmit Data Register.
The internal chip-select output pin remains active as long as the Transmit
Data Register or its shift register are not empty.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the endian agnositc IO functions instead of the __raw ones for when
the driver is in use on big-endian systems.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Additionally to the current DMA transfer the PDC allows to set up a next DMA
transfer. This is useful for larger SPI transfers.
The driver currently waits for ENDRX as end of the transfer. But ENDRX is set
when the current DMA transfer is done (RCR = 0), i.e. it doesn't include the
next DMA transfer.
Thus a subsequent SPI transfer could be started although there is currently a
transfer in progress. This can cause invalid accesses to the SPI slave devices
and to SPI transfer errors.
This issue has been observed on a hardware with a M25P128 SPI NOR flash.
So instead of ENDRX we should wait for RXBUFF. This flag is set if there is
no more DMA transfer in progress (RCR = RNCR = 0).
Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
return type of wait_for_completion_timeout is unsigned long not int, this
patch adds an appropriate variable and fixes up the assignment. It removes
the else branch as the only thing it was doing is assigning ret = 0; - but
ret is never used thereafter so that is not needed. As the string in
dev_err already states "timeout" there is little point in printing the 0.
A typo in "trasfer" -> transfer is also fixed.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
Return probe defer if requesting a dma channel without a dma controller
probed.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
All boards with a dma controller have DT support so using
dma_request_slave_channel_compat is no more needed.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
To make it cleaner, the system suspend/resume directly call
the runtime suspend/resume functions
and remove the wapper of CONFIG_PM_RUNTIME, CONFIG_PM_SLEEP.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/spi-atmel.c:1518:1-4: WARNING: end returns can be simpified and declaration on line 1514 can be dropped
Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Drivers should put the device into low power states proactively whenever the
device is not in use. Thus implement support for runtime PM and use the
autosuspend feature to make sure that we can still perform well in case we see
lots of SPI traffic within short period of time.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
On 64 bit systems integers are generally still 32 bit but long values and
pointers are usually 64 bit. GCC warns when casting a 64 bit pointer into
a 32 bit integer so cast to a long instead in order to avoid warnings.
Signed-off-by: Mark Brown <broonie@linaro.org>
Use the inline wrapper introduced by commit
16052827d9 ("dmaengine/dma_slave: introduce
inline wrappers").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
Found using smatch:
drivers/spi/spi-atmel.c:878 atmel_spi_pump_pio_data() warn: unsigned
'as->current_remaining_bytes' is never less than zero.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
atmel_spi_lock does a spin_lock_irqsave, so we need to renable the
interrupts when we want to schedule.
Signed-off-by: Alexander Stein <alexanders83@web.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Don't use unsigned for current_remaining_bytes so we can check
current_remaining_bytes < 0 case.
Use int is enough for current_remaining_bytes.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
