kernel/linux.git/include/linux/spi/spi.h, branch v3.4.112

spi: fix spi.h kernel-doc warning

2012-04-27T17:03:38+00:00

Fix kernel-doc warning in spi.h (copy/paste): Warning(include/linux/spi/spi.h:365): No description found for parameter 'unprepare_transfer_hardware' Signed-off-by: Randy Dunlap Signed-off-by: Grant Likely

spi: Trivial warning fix

2012-03-09T17:56:10+00:00

The loop count i traverses for ntrans which is unsigned so make the loop count i also unsigned. Fix the below warning In file included from drivers/spi/spi-omap2-mcspi.c:38: include/linux/spi/spi.h: In function 'spi_message_alloc': include/linux/spi/spi.h:556: warning: comparison between signed and unsigned integer expressions Cc: Vitaly Wool Signed-off-by: Shubhrajyoti D Signed-off-by: Grant Likely

spi: create a message queueing infrastructure

2012-03-08T02:19:48+00:00

This rips the message queue in the PL022 driver out and pushes it into (optional) common infrastructure. Drivers that want to use the message pumping thread will need to define the new per-messags transfer methods and leave the deprecated transfer() method as NULL. Most of the design is described in the documentation changes that are included in this patch. Since there is a queue that need to be stopped when the system is suspending/resuming, two new calls are implemented for the device drivers to call in their suspend()/resume() functions: spi_master_suspend() and spi_master_resume(). ChangeLog v1->v2: - Remove Kconfig entry and do not make the queue support optional at all, instead be more agressive and have it as part of the compulsory infrastructure. - If the .transfer() method is implemented, delete print a small deprecation notice and do not start the transfer pump. - Fix a bitrotted comment. ChangeLog v2->v3: - Fix up a problematic sequence courtesy of Chris Blair. - Stop rather than destroy the queue on suspend() courtesy of Chris Blair. Signed-off-by: Chris Blair Signed-off-by: Linus Walleij Tested-by: Mark Brown Reviewed-by: Mark Brown Signed-off-by: Grant Likely

SPI: Add helper macro for spi_driver boilerplate

2011-11-17T20:15:39+00:00

This patch introduces the module_spi_driver macro which is a convenience macro for SPI driver modules similar to module_platform_driver. It is intended to be used by drivers which init/exit section does nothing but register/unregister the SPI driver. By using this macro it is possible to eliminate a few lines of boilerplate code per SPI driver. Signed-off-by: Lars-Peter Clausen Acked-by: Grant Likely Acked-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

spi: Use void pointers for data in simple SPI I/O operations

2011-05-20T06:43:07+00:00

Currently the simple SPI I/O operations all take pointers to u8 * buffers to operate on. This creates needless type compatibility issues and the underlying spi_transfer structure uses void pointers anyway so convert the API over to take void pointers too. Signed-off-by: Mark Brown Signed-off-by: Grant Likely

spi: enable spi_board_info to be registered after spi_master

2010-10-22T05:52:16+00:00

Currently spi_register_board_info() has to be called before its related spi_master be registered, otherwise these board info will be just ignored. This patch will remove this order limit, it adds a global spi master list like the existing global board info listr. Whenever a board info or a spi_master is registered, the spi master list or board info list will be scanned, and a new spi device will be created if there is a master-board info match. Signed-off-by: Feng Tang Signed-off-by: Grant Likely

spi.h: missing kernel-doc notation, please fix

2010-08-18T04:55:38+00:00

Added comments in kernel-doc notation for previously added struct fields. Signed-off-by: Ernst Schwab Acked-by: Randy Dunlap Signed-off-by: Grant Likely

spi/mmc_spi: SPI bus locking API, using mutex

2010-06-29T00:49:29+00:00

SPI bus locking API to allow exclusive access to the SPI bus, especially, but not limited to, for the mmc_spi driver. Coded according to an outline from Grant Likely; here is his specification (accidentally swapped function names corrected): It requires 3 things to be added to struct spi_master. - 1 Mutex - 1 spin lock - 1 flag. The mutex protects spi_sync, and provides sleeping "for free" The spinlock protects the atomic spi_async call. The flag is set when the lock is obtained, and checked while holding the spinlock in spi_async(). If the flag is checked, then spi_async() must fail immediately. The current runtime API looks like this: spi_async(struct spi_device*, struct spi_message*); spi_sync(struct spi_device*, struct spi_message*); The API needs to be extended to this: spi_async(struct spi_device*, struct spi_message*) spi_sync(struct spi_device*, struct spi_message*) spi_bus_lock(struct spi_master*) /* although struct spi_device* might be easier */ spi_bus_unlock(struct spi_master*) spi_async_locked(struct spi_device*, struct spi_message*) spi_sync_locked(struct spi_device*, struct spi_message*) Drivers can only call the last two if they already hold the spi_master_lock(). spi_bus_lock() obtains the mutex, obtains the spin lock, sets the flag, and releases the spin lock before returning. It doesn't even need to sleep while waiting for "in-flight" spi_transactions to complete because its purpose is to guarantee no additional transactions are added. It does not guarantee that the bus is idle. spi_bus_unlock() clears the flag and releases the mutex, which will wake up any waiters. The difference between spi_async() and spi_async_locked() is that the locked version bypasses the check of the lock flag. Both versions need to obtain the spinlock. The difference between spi_sync() and spi_sync_locked() is that spi_sync() must hold the mutex while enqueuing a new transfer. spi_sync_locked() doesn't because the mutex is already held. Note however that spi_sync must *not* continue to hold the mutex while waiting for the transfer to complete, otherwise only one transfer could be queued up at a time! Almost no code needs to be written. The current spi_async() and spi_sync() can probably be renamed to __spi_async() and __spi_sync() so that spi_async(), spi_sync(), spi_async_locked() and spi_sync_locked() can just become wrappers around the common code. spi_sync() is protected by a mutex because it can sleep spi_async() needs to be protected with a flag and a spinlock because it can be called atomically and must not sleep Signed-off-by: Ernst Schwab [grant.likely@secretlab.ca: use spin_lock_irqsave()] Signed-off-by: Grant Likely Tested-by: Matt Fleming Tested-by: Antonio Ospite

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

spi: handle TX-only/RX-only

2009-09-23T14:39:44+00:00

Support two new half-duplex SPI implementation restrictions, for links that talk to TX-only or RX-only devices. (Existing half-duplex flavors support both transfer directions, just not at the same time.) Move spi_async() into the spi.c core, and stop inlining it. Then make that function perform error checks and reject messages that demand more than the underlying controller can support. Based on a patch from Marek Szyprowski which did this only for the bitbanged GPIO driver. Cc: Marek Szyprowski Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds