Commit Graph

308 Commits

Author SHA1 Message Date
Mark Brown 3bc1ad252d Merge remote-tracking branches 'spi/topic/delay', 'spi/topic/dw', 'spi/topic/fsl-dspi' and 'spi/topic/fsl-espi' into spi-next 2016-12-12 15:54:09 +00:00
Mark Brown cc939939d8 Merge remote-tracking branch 'spi/topic/dma' into spi-next 2016-12-12 15:54:03 +00:00
Mark Brown 0523266950 Merge remote-tracking branch 'spi/topic/core' into spi-next 2016-12-12 15:54:03 +00:00
Juan Gutierrez 8dd4a0163e spi: use sg_next for walking through the allocated scatterlist table
A null dereference or Oops exception might occurs when reading at once the
whole content of an spi-nor of big enough size that requires an scatterlist
table that does not fit into one single page.

The spi_map_buf function is ignoring the chained sg case by dereferenceing
the scatterlist elements in an array fashion. This wrongly assumes that
the allocation of the scatterlist elements are contiguous. This is true as
long as the scatterlist table fits within a PAGE_SIZE. However, for
allocation where the scatter table is bigger than that, the pages allocated
by sg_alloc might not be contigous.

The sg table can be properly walked by sg_next instead of using an array.

Signed-off-by: Juan Gutierrez <juan.gutierrez@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-22 16:27:31 +00:00
Daniel Kurtz 8244bd3ab4 spi: change post transfer udelay() to usleep_range() for long delays
The spi_transfer parameter delay_usecs allows specifying a time to wait
after transferring a spi message.  This wait can be quite long - some
devices, such as some Chrome OS ECs, require as much as 2000 usecs after
a SPI transaction, before it can respond.

(cf: arch/arm64/boot/dts/nvidia/tegra132-norrin.dts:
   google,cros-ec-spi-msg-delay = <2000>
)

Blocking a CPU for 2 msecs in a busy loop like this doesn't seem very
friendly to other processes, so change the blocking delay to a sleep
to allow other things to use this CPU (or so it can sleep).

This should be safe to do, because:
 (a) A post-transaction delay like this is always specified as a minimum
     wait time
 (b) A delay here is most likely not very time sensitive, as it occurs
     after all data has been transferred
 (c) This delay occurs in a non-critical section of the spi worker thread
     so where it is safe to sleep.

Two caveats:
 1) To avoid penalizing short delays, still use udelay for delays < 10us.
 2) usleep_range() very often picks the upper bound, an upper bounds 10%
    should be plenty.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-26 12:35:17 +01:00
Ralf Ramsauer e0af98a7e0 spi: mark device nodes only in case of successful instantiation
Instantiated SPI device nodes are marked with OF_POPULATE. This was
introduced in bd6c164. On unloading, loaded device nodes will of course
be unmarked. The problem are nodes that fail during initialisation: If a
node fails, it won't be unloaded and hence not be unmarked.

If a SPI driver module is unloaded and reloaded, it will skip nodes that
failed before.

Skip device nodes that are already populated and mark them only in case
of success.

Note that the same issue exists for I2C.

Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2016-10-24 18:29:33 +01:00
Thor Thayer 8eee6b9dd3 spi: Add Flag to Enable Slave Select with GPIO Chip Select.
Some SPI masters require slave selection before the transfer
can begin [1]. The SPI framework currently selects the chip using
either 1) the internal CS mechanism or 2) the GPIO CS, but not both.

This patch adds a new master->flags define to indicate both the GPIO
CS and the internal chip select mechanism should be used.

Tested On:
    Altera CycloneV development kit
    Compile tested for build errors on x86_64 (allyesconfigs)

[1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-21 12:09:30 +01:00
Petr Mladek 3989144f86 kthread: kthread worker API cleanup
A good practice is to prefix the names of functions by the name
of the subsystem.

The kthread worker API is a mix of classic kthreads and workqueues.  Each
worker has a dedicated kthread.  It runs a generic function that process
queued works.  It is implemented as part of the kthread subsystem.

This patch renames the existing kthread worker API to use
the corresponding name from the workqueues API prefixed by
kthread_:

__init_kthread_worker()		-> __kthread_init_worker()
init_kthread_worker()		-> kthread_init_worker()
init_kthread_work()		-> kthread_init_work()
insert_kthread_work()		-> kthread_insert_work()
queue_kthread_work()		-> kthread_queue_work()
flush_kthread_work()		-> kthread_flush_work()
flush_kthread_worker()		-> kthread_flush_worker()

Note that the names of DEFINE_KTHREAD_WORK*() macros stay
as they are. It is common that the "DEFINE_" prefix has
precedence over the subsystem names.

Note that INIT() macros and init() functions use different
naming scheme. There is no good solution. There are several
reasons for this solution:

  + "init" in the function names stands for the verb "initialize"
    aka "initialize worker". While "INIT" in the macro names
    stands for the noun "INITIALIZER" aka "worker initializer".

  + INIT() macros are used only in DEFINE() macros

  + init() functions are used close to the other kthread()
    functions. It looks much better if all the functions
    use the same scheme.

  + There will be also kthread_destroy_worker() that will
    be used close to kthread_cancel_work(). It is related
    to the init() function. Again it looks better if all
    functions use the same naming scheme.

  + there are several precedents for such init() function
    names, e.g. amd_iommu_init_device(), free_area_init_node(),
    jump_label_init_type(),  regmap_init_mmio_clk(),

  + It is not an argument but it was inconsistent even before.

[arnd@arndb.de: fix linux-next merge conflict]
 Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:33 -07:00
Thor Thayer 6b1576aa87 spi: Add Flag to Enable Slave Select with GPIO Chip Select.
Some SPI masters require slave selection before the transfer
can begin [1]. The SPI framework currently selects the chip using
either 1) the internal CS mechanism or 2) the GPIO CS, but not both.

This patch adds a new master->flags define to indicate both the GPIO
CS and the internal chip select mechanism should be used.

Tested On:
    Altera CycloneV development kit
    Compile tested for build errors on x86_64 (allyesconfigs)

[1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-11 12:29:04 +02:00
Mark Brown c5aee51b7a Merge remote-tracking branch 'spi/topic/dma' into spi-next 2016-09-30 09:14:07 -07:00
Mark Brown ae4860b533 Merge remote-tracking branches 'spi/fix/lock', 'spi/fix/maintainers', 'spi/fix/put', 'spi/fix/pxa2xx', 'spi/fix/sh-msiof' and 'spi/fix/timeout' into spi-linus 2016-09-06 12:32:09 +01:00
Sien Wu d0716dde37 spi: Prevent unexpected SPI time out due to arithmetic overflow
When reading SPI flash as MTD device, the transfer length is
directly passed to the spi driver. If the requested data size
exceeds 512KB, it will cause the time out calculation to
overflow since transfer length is 32-bit unsigned integer.
This issue is resolved by using 64-bit unsigned integer
to perform the arithmetic.

Signed-off-by: Sien Wu <sien.wu@ni.com>
Acked-by: Brad Keryan <brad.keryan@ni.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Acked-by: Brad Mouring <brad.mouring@ni.com>

Natinst-ReviewBoard-ID 150232
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-09-03 11:58:13 +01:00
Vignesh R b1b8153cf0 spi: Add support to handle kmap'd buffers in spi_map_buf()
JFFS2 FS might sometime provide kmap'd buffers as destination
buffers to read data from flash. Update spi_map_buf() function to
generate sg_list for such buffers, so that SPI controllers drivers can
use DMA to read data into such buffers.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-17 12:24:01 +01:00
Mark Brown 764f21665a spi: Drop io_mutex in error paths
A couple of error paths were missing drops of io_mutex.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-09 17:45:33 +01:00
Linus Torvalds 7ae0ae4a02 spi: Updates for v4.8
Quite a lot of cleanup and maintainence work going on this release in
 various drivers, and also a fix for a nasty locking issue in the core:
 
  - A fix for locking issues when external drivers explicitly locked the
    bus with spi_bus_lock() - we were using the same lock to both control
    access to the physical bus in multi-threaded I/O operations and
    exclude multiple callers.  Confusion between these two caused us to
    have scenarios where we were dropping locks.  These are fixed by
    splitting into two separate locks like should have been done
    originally, making everything much clearer and correct.
  - Support for DMA in spi_flash_read().
  - Support for instantiating spidev on ACPI systems, including some test
    devices used in Windows validation.
  - Use of the core DMA mapping functionality in the McSPI driver.
  - Start of support for ThunderX SPI controllers, involving a very big
    set of changes to the Cavium driver.
  - Support for Braswell, Exynos 5433, Kaby Lake, Merrifield, RK3036,
    RK3228, RK3368 controllers.
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Merge tag 'spi-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Quite a lot of cleanup and maintainence work going on this release in
  various drivers, and also a fix for a nasty locking issue in the core:

   - A fix for locking issues when external drivers explicitly locked
     the bus with spi_bus_lock() - we were using the same lock to both
     control access to the physical bus in multi-threaded I/O operations
     and exclude multiple callers.

     Confusion between these two caused us to have scenarios where we
     were dropping locks.  These are fixed by splitting into two
     separate locks like should have been done originally, making
     everything much clearer and correct.

   - Support for DMA in spi_flash_read().

   - Support for instantiating spidev on ACPI systems, including some
     test devices used in Windows validation.

   - Use of the core DMA mapping functionality in the McSPI driver.

   - Start of support for ThunderX SPI controllers, involving a very big
     set of changes to the Cavium driver.

   - Support for Braswell, Exynos 5433, Kaby Lake, Merrifield, RK3036,
     RK3228, RK3368 controllers"

* tag 'spi-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (64 commits)
  spi: Split bus and I/O locking
  spi: octeon: Split driver into Octeon specific and common parts
  spi: octeon: Move include file from arch/mips to drivers/spi
  spi: octeon: Put register offsets into a struct
  spi: octeon: Store system clock freqency in struct octeon_spi
  spi: octeon: Convert driver to use readq()/writeq() functions
  spi: pic32-sqi: fixup wait_for_completion_timeout return handling
  spi: pic32: fixup wait_for_completion_timeout return handling
  spi: rockchip: limit transfers to (64K - 1) bytes
  spi: xilinx: Return IRQ_NONE if no interrupts were detected
  spi: xilinx: Handle errors from platform_get_irq()
  spi: s3c64xx: restore removed comments
  spi: s3c64xx: add Exynos5433 compatible for ioclk handling
  spi: s3c64xx: use error code from clk_prepare_enable()
  spi: s3c64xx: rename goto labels to meaningful names
  spi: s3c64xx: document the clocks and the clock-name property
  spi: s3c64xx: add exynos5433 spi compatible
  spi: s3c64xx: fix reference leak to master in s3c64xx_spi_remove()
  spi: spi-sh: Remove deprecated create_singlethread_workqueue
  spi: spi-topcliff-pch: Remove deprecated create_singlethread_workqueue
  ...
2016-07-27 14:11:43 -07:00
Mark Brown ef4d96ec4a spi: Split bus and I/O locking
The current SPI code attempts to use bus_lock_mutex for two purposes. One
is to implement spi_bus_lock() which grants exclusive access to the bus.
The other is to serialize access to the physical hardware. This duplicate
purpose causes confusion which leads to cases where access is not locked
when a caller holds the bus lock mutex. Fix this by splitting out the I/O
functionality into a new io_mutex.

This means taking both mutexes in the DMA path, replacing the existing
mutex with the new I/O one in the message pump (the mutex now always
being taken in the message pump) and taking the bus lock mutex in
spi_sync(), allowing __spi_sync() to have no mutex handling.

While we're at it hoist the mutex further up the message pump before we
power up the device so that all power up/down of the block is covered by
it and there are no races with in-line pumping of messages.

Reported-by: Rich Felker <dalias@libc.org>
Tested-by: Rich Felker <dalias@libc.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-07-25 11:47:52 +01:00
Octavian Purdila 7f24467f3b spi / ACPI: add support for ACPI reconfigure notifications
This patch adds supports for SPI device enumeration and removal via
ACPI reconfiguration notifications that are send as a result of an
ACPI table load or unload operation.

The code is very similar with the device tree reconfiguration code
with only small differences in the way we test and set the enumerated
state of the device:

 * the equivalent of device tree's OF_POPULATED flag is the
   flags.visited field in the ACPI device and the following wrappers
   are used to manipulate it: acpi_device_enumerated(),
   acpi_device_set_enumerated() and acpi_device_clear_enumerated()

 * the device tree code checks of status of the OF_POPULATED flag to
   avoid trying to create duplicate Linux devices in two places: once
   when the controller is probed, and once when the reconfigure event
   is received; in the ACPI code the check is performed only once when
   the ACPI namespace is searched because this code path is invoked in
   both of the two mentioned cases

The rest of the enumeration handling is similar with device tree: when
the Linux device is unregistered the ACPI device is marked as not
enumerated; also, when a device remove notification is received we
check that the device is in the enumerated state before continuing
with the removal of the Linux device.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-08 21:52:35 +02:00
Vignesh R f4502dd1da spi: Add DMA support for spi_flash_read()
Few SPI devices provide accelerated read interfaces to read from
SPI-NOR flash devices. These hardwares also support DMA to transfer data
from flash to memory either via mem-to-mem DMA or dedicated slave DMA
channels. Hence, add support for DMA in order to improve throughput and
reduce CPU load.
Use spi_map_buf() to get sg table for the buffer and pass it to SPI
driver.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-06-08 10:26:46 +01:00
Mark Brown 38acceff8f Merge remote-tracking branch 'spi/topic/core' into spi-next 2016-05-23 12:16:45 +01:00
Moritz Fischer 8ba811a7d2 spi: Fix simple typo s/impelment/implement
This fixes a simple typo in one of the comments.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-05-04 14:42:23 +01:00
Vignesh R 0569a88f3d spi: return error if kmap'd buffers passed to spi_map_buf()
Current spi_map_buf() implementation supports creates sg_table for
vmalloc'd and kmalloc'd buffers. Therefore return error if kmap'd buffer
(or any other buffer) is passed to spi_map_buf().

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-25 18:55:57 +01:00
Linus Walleij d7e2ee2570 spi: let SPI masters ignore their children for PM
Let all SPI masters ignore their children: when it comes
to power management: SPI children have no business doing
keeping their parents awake: they are completely autonomous
devices that just use their parent to talk, and the latter
usecase must be power managed by the host itself on a
per-message basis.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-12 04:48:31 +01:00
Heiko Stübner 24c8cd1b08 spi: fix possible deadlock between internal bus locks and bus_lock_flag
External users may use spi_bus_lock to get exclusive access. This will
also grab the bus_lock_mutex and may therefore result in a deadlock if
__spi_pump_messages also tries to get the mutex.

Therefore adapt spi_pump_messages as well as spi_sync to preset the
bus_locked parameter according to the master->bus_lock_flag.

Fixes: 49023d2e4e ("spi: core: Fix deadlock when sending messages")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-18 10:37:09 +00:00
Mark Brown b9facea19b Merge remote-tracking branches 'spi/topic/lp8841', 'spi/topic/msg', 'spi/topic/pl022' and 'spi/topic/pxa2xx' into spi-next 2016-03-11 14:28:43 +07:00
Mark Brown f91c75d6fa Merge remote-tracking branches 'spi/topic/doc', 'spi/topic/dw' and 'spi/topic/flash' into spi-next 2016-03-11 14:28:35 +07:00
Mark Brown 6beb9fecbd Merge remote-tracking branches 'spi/topic/acpi', 'spi/topic/axi-engine', 'spi/topic/bcm2835' and 'spi/topic/bcm2835aux' into spi-next 2016-03-11 14:28:25 +07:00
Mark Brown a75481ab4a Merge remote-tracking branch 'spi/topic/dma' into spi-next 2016-03-11 14:28:20 +07:00
Javier Martinez Canillas 10f11a2238 spi: Add gfp parameter to kernel-doc to fix build warning
The spi_split_transfers_maxsize() gfp parameter is missing in the
function kernel-doc so building gives the following warning:

.//drivers/spi/spi.c:2359: warning: No description found for parameter 'gfp'

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-11 14:23:01 +07:00
Andy Shevchenko df88e91bbf spi: respect the maximum segment size of DMA device
The device which is actually does DMA may have a limitation of the maximum
segment size. Respect this setting when preparing scatter-gather list.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-09 16:33:52 +07:00
Jon Hunter 49023d2e4e spi: core: Fix deadlock when sending messages
The function __spi_pump_messages() is called by spi_pump_messages() and
__spi_sync(). The function __spi_sync() has an argument 'bus_locked'
that indicates if it is called with the SPI bus mutex held or not. If
'bus_locked' is false then __spi_sync() will acquire the mutex itself.

Commit 556351f14e ("spi: introduce accelerated read support for spi
flash devices") made a change to acquire the SPI bus mutex within
__spi_pump_messages(). However, this change did not check to see if the
mutex is already held. If __spi_sync() is called with the mutex held
(ie. 'bus_locked' is true), then a deadlock occurs when
__spi_pump_messages() is called.

Fix this deadlock by passing the 'bus_locked' state from __spi_sync() to
__spi_pump_messages() and only acquire the mutex if not already held. In
the case where __spi_pump_messages() is called from spi_pump_messages()
it is assumed that the mutex is not held and so call
__spi_pump_messages() with 'bus_locked' set to false. Finally, move the
unlocking of the mutex to the end of the __spi_pump_messages() function
to simplify the code and only call cond_resched() if there are no
errors.

Fixes: 556351f14e ("spi: introduce accelerated read support for spi flash devices")

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-09 09:31:39 +07:00
Masanari Iida 3700ce951c spi: make xmldocs warning caused by spi.c
This patch fix following warnings while make xmldocs.

.//drivers/spi/spi.c:2354: warning: Excess function parameter
'message' description in 'spi_split_transfers_maxsize'
.//drivers/spi/spi.c:2354: warning: Excess function parameter
 'max_size' description in 'spi_split_transfers_maxsize'

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-22 23:06:19 +09:00
Mark Brown 628269704f spi: Add cond_resched() in main message processing loop
When a controller has only PIO support it is very likely that we will
run into use cases where we spend a very large amount of time consuming
CPU.  Code that does this should call cond_resched() every once in a
while to give other tasks more of a chance to run so do that in the main
SPI loop, the overhead is negligable if it's not needed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-18 17:41:44 +00:00
Martin Sperl 058853979f spi: docbook: add missing parameter documentation
Add missing docbook documentation for the gfp parameter
in function spi_replace_transfers.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-18 17:00:12 +00:00
Fabio Estevam c8dab77a1f spi: core: Use min_t(size_t,..)
Use min_t(size_t,..) in order to avoid the following
build warning on ARM64:

include/linux/kernel.h:754:17: warning: comparison of distinct pointer types lacks a cast
  (void) (&_min1 == &_min2);  \
                 ^
drivers/spi/spi.c:2304:17: note: in expansion of macro 'min'
  xfers[0].len = min(maxsize, xfer[0].len);

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-17 19:17:10 +00:00
Fabio Estevam 7d62f51e74 spi: core: Use %zu for printing 'size_t' type
Use %zu for printing 'size_t' type in order to fix the following
build warning on ARM64:

drivers/spi/spi.c: In function '__spi_split_transfer_maxsize':
drivers/spi/spi.c:2278:2: warning: format '%i' expects argument of type 'int', but argument 4 has type 'size_t' [-Wformat=]

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-17 19:16:53 +00:00
Fabio Estevam 08933418d7 spi: core: Staticize __spi_split_transfer_maxsize()
__spi_split_transfer_maxsize() can be made static as it is only
used in this file.

This fixes the following sparse warning:

drivers/spi/spi.c:2266:5: warning: symbol '__spi_split_transfer_maxsize' was not declared. Should it be static?

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-15 19:55:46 +00:00
Dan Carpenter 657d32efe0 spi: checking for NULL instead of IS_ERR
spi_replace_transfers() returns error pointers on error, it never
returns NULL.

Fixes: d9f1212272 ('spi: core: add spi_split_transfers_maxsize')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-12 23:03:56 +00:00
Vignesh R 556351f14e spi: introduce accelerated read support for spi flash devices
In addition to providing direct access to SPI bus, some spi controller
hardwares (like ti-qspi) provide special port (like memory mapped port)
that are optimized to improve SPI flash read performance.
This means the controller can automatically send the SPI signals
required to read data from the SPI flash device.
For this, SPI controller needs to know flash specific information like
read command to use, dummy bytes and address width.

Introduce spi_flash_read() interface to support accelerated read
over SPI flash devices. SPI master drivers can implement this callback to
support interfaces such as memory mapped read etc. m25p80 flash driver
and other flash drivers can call this make use of such interfaces. The
interface should only be used with SPI flashes and cannot be used with
other SPI devices.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-09 19:34:02 +00:00
Martin Sperl d9f1212272 spi: core: add spi_split_transfers_maxsize
Add spi_split_transfers_maxsize method that splits
spi_transfers transparently into multiple transfers
that are below the given max-size.

This makes use of the spi_res framework via
spi_replace_transfers to allocate/free the extra
transfers as well as reverting back the changes applied
while processing the spi_message.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-09 19:32:07 +00:00
Martin Sperl 523baf5a06 spi: core: add spi_replace_transfers method
Add the spi_replace_transfers method that can get used
to replace some spi_transfers from a spi_message with other
transfers.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-09 19:32:07 +00:00
Martin Sperl d780c3711d spi: core: added spi_resource management
SPI resource management framework used while processing a spi_message
via the spi-core.

The basic idea is taken from devres, but as the allocation may happen
fairly frequently, some provisioning (in the form of an unused spi_device
pointer argument to spi_res_alloc) has been made so that at a later stage
we may implement reuse objects allocated earlier avoiding the repeated
allocation by keeping a cache of objects that we can reuse.

This framework can get used for:
* rewriting spi_messages
  * to fullfill alignment requirements of the spi_master HW
  * to fullfill transfer length requirements
    (e.g: transfers need to be less than 64k)
  * consolidate spi_messages with multiple transfers into a single transfer
  when the total transfer length is below a threshold.
* reimplement spi_unmap_buf without explicitly needing to check if it has
  been mapped

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-09 19:25:43 +00:00
Mika Westerberg a0a90718f1 spi: Let drivers translate ACPI DeviceSelection to suitable Linux chip select
In Windows it is up to the SPI host controller driver to handle the ACPI
DeviceSelection as it likes. The SPI core does not take any part in it.
This is different in Linux because we always expect to have chip select in
range of 0 .. master->num_chipselect - 1.

In order to support this in Linux we need a way to allow the driver to
translate between ACPI DeviceSelection field and Linux chip select number
so provide a new optional hook ->fw_translate_cs() that can be used by a
driver to handle translation and call this hook if set during SPI slave
ACPI enumeration.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-09 18:19:40 +00:00
Linus Torvalds 50ae833e47 spi: Updates for v4.5
A quiet release for SPI, not even many driver updates:
 
  - Add a dummy loopback driver for use in exercising framework features
    during development.
  - Move the test utilities to tools/ and add support for transferring
    data to and from a file instead of stdin and stdout to spidev_test.
  - Support for Mediatek MT2701 and Renesas AG5 deices.
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Merge tag 'spi-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "A quiet release for SPI, not even many driver updates:

   - Add a dummy loopback driver for use in exercising framework
     features during development.

   - Move the test utilities to tools/ and add support for transferring
     data to and from a file instead of stdin and stdout to spidev_test.

   - Support for Mediatek MT2701 and Renesas AG5 deices"

* tag 'spi-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (69 commits)
  spi: loopback: fix typo in MODULE_PARM_DESC
  spi: sun4i: Prevent chip-select from being activated twice before a transfer
  spi: loopback-test: spi_check_rx_ranges can get always done
  spi: loopback-test: rename method spi_test_fill_tx to spi_test_fill_pattern
  spi: loopback-test: write rx pattern also when running without tx_buf
  spi: fsl-espi: expose maximum transfer size limit
  spi: expose master transfer size limitation.
  spi: zynq: use to_platform_device()
  spi: cadence: use to_platform_device()
  spi: mediatek: Add spi support for mt2701 IC
  spi: mediatek: merge all identical compat to mtk_common_compat
  spi: mtk: Add bindings for mediatek MT2701 soc platform
  spi: mediatek: Prevent overflows in FIFO transfers
  spi: s3c64xx: Remove unused platform_device_id entries
  spi: use to_spi_device
  spi: dw: Use SPI_TMOD_TR rather than magic const 0 to set tmode
  spi: imx: defer spi initialization, if DMA engine is
  spi: imx: return error from dma channel request
  spi: imx: enable loopback only for ECSPI controller family
  spi: imx: fix loopback mode setup after controller reset
  ...
2016-01-13 11:38:27 -08:00
Mark Brown 4f9530705b Merge remote-tracking branches 'spi/topic/overlay', 'spi/topic/pxa2xx', 'spi/topic/s3c64xx', 'spi/topic/sh-msiof' and 'spi/topic/spidev' into spi-next 2016-01-11 16:48:35 +00:00
Mark Brown 174c21163d Merge remote-tracking branch 'spi/topic/core' into spi-next 2016-01-11 16:48:29 +00:00
Christophe RICARD 33ada67da3 ACPI / spi: attach GPIO IRQ from ACPI description to SPI device
spi->irq was ignoring GpioInt property setting it to -1.
acpi_dev_gpio_irq_get returns and configure the slave IRQ according to
the ACPI slave node description.

It is now inline with devicetree behavior.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-01 03:20:25 +01:00
Geliang Tang d1eba93bd0 spi: use to_spi_device
Use to_spi_device() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-23 12:15:41 +00:00
Mark Brown 9ce5db27f4 Merge remote-tracking branch 'spi/fix/core' into spi-linus 2015-12-16 13:28:31 +00:00
Johan Hovold 157f38f993 spi: fix parent-device reference leak
Fix parent-device reference leak due to SPI-core taking an unnecessary
reference to the parent when allocating the master structure, a
reference that was never released.

Note that driver core takes its own reference to the parent when the
master device is registered.

Fixes: 49dce689ad ("spi doesn't need class_device")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-12-16 12:28:25 +00:00
Geert Uytterhoeven bd6c1644a2 spi: Mark instantiated device nodes with OF_POPULATE
Mark (and unmark) device nodes with the POPULATE flag as appropriate.
This is required to avoid multi probing when enabling and populating SPI
buses in DT overlays.

Based on commit 4f001fd301 ("i2c: Mark instantiated device nodes
with OF_POPULATE").

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-01 18:52:20 +00:00