Add SPI_3WIRE support to spi-gpio controller introducing
set_line_direction function pointer in spi_bitbang data structure.
Spi-gpio controller has been tested using hts221 temp/rh iio sensor
running in 3wire mode and lsm6dsm running in 4wire mode
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add the capability to specify the flag parameter used in
bitbang_txrx_be_cpha{0,1} through the txrx_word function pointers of
spi_bitbang data structure. That feature will be used to add spi-3wire
support to the spi-gpio controller
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Change the bitbang driver to use the generic implementation of
transfer_one_message. This simplifies the bitbang driver code and
provides benefits like the statistics in the generic implementation.
Successfully tested on a IMX6-based system (spi-imx) and on a MIPS-based
router (OpenWRT with spi-ath79).
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove an unneeded check. The SPI core (__spi_validate) takes care
that these fields are always populated.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
chipselect (in the case of spi-gpio: spi_gpio_chipselect, which
calls gpiod_set_raw_value_cansleep) can sleep, so we should not
hold a spinlock while calling it from spi_bitbang_setup.
This issue was introduced by this commit, which converted spi-gpio
to cansleep variants:
d9dda5a191 "spi: spi-gpio: Use 'cansleep' variants to access GPIO"
Replacing the lock variable by a mutex fixes the issue: This is
safe as all instances where the lock is used are called from
contexts that can sleep.
Finally, update spi-ppc4xx and and spi-s3c24xx to use mutex
functions, as they directly hold the lock for similar purpose.
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Some controller drivers have no need of this callback (spi-altera even
causes a NULL pointer dereference because it doesn't register the callback,
falsely assuming that it is already optional).
Fixes: 30af9b558a ("spi/bitbang: Drop empty setup() functions")
Signed-off-by: Pelle Nilsson <per.nilsson@xelmo.com>
Reviewed-by: Ezequiel Garcia <ezequiel.garcia@vanguardiasur.com.ar>
Signed-off-by: Mark Brown <broonie@kernel.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>
Fix the following checkpatch warnings
WARNING: sizeof *cs should be sizeof(*cs)
WARNING: please, no space before tabs
WARNING: space prohibited between function name and open parenthesis '('
WARNING: line over 80 characters
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Many drivers that use bitbang library have a leak on probe error paths.
This is because once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory.
Fix this issue by moving the code taking a reference to master to
spi_bitbang_start(), so spi_bitbang_start() will take a reference to master on
success. With this change, the caller is responsible for calling
spi_bitbang_stop() to decrement the reference and spi_master_put() as
counterpart of spi_alloc_master() to prevent a memory leak.
So now we have below patten for drivers using bitbang library:
probe:
spi_alloc_master -> Init reference count to 1
spi_bitbang_start -> Increment reference count
remove:
spi_bitbang_stop -> Decrement reference count
spi_master_put -> Decrement reference count (reference count reaches 0)
Fixup all users accordingly.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Suggested-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull trivial tree from Jiri Kosina:
"The usual trivial updates all over the tree -- mostly typo fixes and
documentation updates"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits)
doc: Documentation/cputopology.txt fix typo
treewide: Convert retrun typos to return
Fix comment typo for init_cma_reserved_pageblock
Documentation/trace: Correcting and extending tracepoint documentation
mm/hotplug: fix a typo in Documentation/memory-hotplug.txt
power: Documentation: Update s2ram link
doc: fix a typo in Documentation/00-INDEX
Documentation/printk-formats.txt: No casts needed for u64/s64
doc: Fix typo "is is" in Documentations
treewide: Fix printks with 0x%#
zram: doc fixes
Documentation/kmemcheck: update kmemcheck documentation
doc: documentation/hwspinlock.txt fix typo
PM / Hibernate: add section for resume options
doc: filesystems : Fix typo in Documentations/filesystems
scsi/megaraid fixed several typos in comments
ppc: init_32: Fix error typo "CONFIG_START_KERNEL"
treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks
page_isolation: Fix a comment typo in test_pages_isolated()
doc: fix a typo about irq affinity
...
It's perfectly valid not to have a setup callback when the probe routine
does all the needed things. So don't even check for this case and trust
the caller.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Since commit 2025172e3 (spi/bitbang: Use core message pump), the following
kernel crash is seen:
Unable to handle kernel NULL pointer dereference at virtual address 0000000d
pgd = 80004000
[0000000d] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 1 PID: 48 Comm: spi32766 Not tainted 3.11.0-rc1+ #4
task: bfa3e580 ti: bfb90000 task.ti: bfb90000
PC is at spi_bitbang_transfer_one+0x50/0x248
LR is at spi_bitbang_transfer_one+0x20/0x248
...
,and also the following build warning:
drivers/spi/spi-bitbang.c: In function 'spi_bitbang_start':
drivers/spi/spi-bitbang.c:436:31: warning: assignment from incompatible pointer type [enabled by default]
In order to fix it, we need to change the first parameter of
spi_bitbang_transfer_one() to 'struct spi_master *master'.
Tested on a mx6qsabrelite by succesfully probing a SPI NOR flash.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Convert drivers using bitbang to use the core mesasge pump infrastructure,
saving some code and meaning that these drivers get to take advantage of
work done on improving the core implementation.
Signed-off-by: Mark Brown <broonie@linaro.org>
In order to make it easier to convert to transfer_one_message() lift the
code that does the actual message transfer out of the work function that
implements the message pump. This should have no functional impact, it's
just a simple code motion patch.
Signed-off-by: Mark Brown <broonie@linaro.org>
Currently no drivers use the ability to override spi_bitbang_transfer()
and if any started this would make it harder to convert the bitbang code
to use transfer_one_message() so remove the export in order to prevent
anyone starting.
Signed-off-by: Mark Brown <broonie@linaro.org>
Minor features and bug fixes for PXA, OMAP and GPIO deivce drivers and a
cosmetic change to the bitbang driver.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The spi core make sure that each transfer structure have the proper
setting for bits_per_word before calling low level transfer APIs.
Hence it is no more require to check again in low level driver for
this field whether this is set correct or not. Removing such code
from low level driver.
The txx9 change also removes a test for bits_per_word set to 0, and
forcing it to 8 in that case. This can also be removed now since
spi_setup() ensures spi->bits_per_word is not zero.
if (!spi->bits_per_word)
spi->bits_per_word = 8;
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Add a pointer variable to make spi_bitbang_start() look simpler.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Use a proper list iterator instead of an open-coded loop and remove a
superfluous list head initialisation.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch makes a loop look cleaner by replacing a "break" and a "continue"
in its body by a single "if".
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
We are clipping down the presence of module.h, since it was
everywhere. If you really need it, you better call it out,
as per this changeset.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.
This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.
v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
be the predominant pattern for subsystem prefixes.
- Clean up filenames in Kconfig and header comment blocks
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
