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>
Fix printk format warning by using %p extension 'ad' for dma_addr_t.
drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]
drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 9 has type 'dma_addr_t' [-Wformat]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The PM callbacks implemented by the spi-atmel driver don't call
spi_master_{resume,suspend}, fix that.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Amend the spi atmel pin controller to optionally take a pin control
handle and set the state of the pins to:
- "default" on boot, resume and before performing an spitransfer
- "sleep" on suspend()
This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
spi core will handle validating transfer length since commit 4d94bd21b3
"spi: core: Validate length of the transfers in message".
So remove the same checking in this driver.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
In spi_add_device(), we have the code to validate spi->chip_select.
So remove the duplicate code in various drivers.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Replace the deprecated master->transfer with transfer_one_message()
and allow the SPI subsystem handle all the queuing of messages.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The only speed available was max_speed (the maximum speed declared for a
device).
This patch adds the support for spi_tranfer->speed_hz parameter.
We can now set a different speed for each spi message.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Use devm_*() functions to make cleanup paths simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
User-visible strings are more difficult to grep from sources if they are
separated to multiple source lines. This is worse than over 80 columns long
line code style violation.
Fix this by making those to single-line strings or by breaking them between
variables.
While at there, convert if (printk_ratelimit()) dev_warn() to use
dev_warn_ratelimited in spi-pxa2xx.c.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fix the following checkpatch warning.
WARNING: quoted string split across lines
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
'irq' was not released when clk_prepare_enable failed.
Fix it.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fixes the following types of checkpatch errors and warning:
ERROR: space required after that ',' (ctx:VxV)
WARNING: sizeof *as should be sizeof(*as)
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Instead of using legacy suspend/resume methods, using newer
dev_pm_ops structure allows better control over power management.
Also, duplicated 'return' is removed from atmel_spi_resume().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This patch fixes the following sparse warnings.
dma_addr_t can be either u32 or u64 so we should cast to the
largest type and use the format specifier %llx.
drivers/spi/spi-atmel.c: In function ‘atmel_spi_next_xfer_dma_submit’:
drivers/spi/spi-atmel.c:631:2: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:631:2: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c: In function ‘atmel_spi_pdc_next_xfer’:
drivers/spi/spi-atmel.c:734:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:734:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:773:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:773:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]
Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Use generic DMA DT helper.
Platforms booting with or without DT populated are both supported.
Based on Ludovic Desroches <ludovic.desroches@atmel.com> patchset
"ARM: at91: move to generic DMA device tree binding"
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fill in the recently added spi_master.bits_per_word_mask field in as
many drivers as possible. Make related cleanups, such as removing any
redundant error-checking, or empty setup callbacks.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Fix using PIO transfer mode only support 8 bits transfer, doesn't support 16 bits.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Add dmaengine support.
Using "has_dma_support" member of struct is used to select
the transfer mode: dmaengine or pdc.
For the dmaengine transfer mode, it supports both 8 bits and 16 bits transfer.
For the dmaengine transfer mode, if it fails to config dmaengine,
or if the message length is less than 16 bytes, it will use the PIO transfer mode.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[wenyou.yang@atmel.com: using "has_dma_support" to select dmaengine as the spi xfer mode]
[wenyou.yang@atmel.com: fix DMA: OOPS if buffer > 4096 bytes]
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
[richard.genoud@gmail.com: update with dmaengine interface]
[richard.genoud@gmail.com: fix __init/__devinit sections mismatch]
[richard.genoud@gmail.com: adapt to slave_config changes]
[richard.genoud@gmail.com: add support t0 16 bits transfer]
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cyrille Pitchen