1. 06 12月, 2012 1 次提交
    • M
      spi: Remove SPI_BUFSIZ restriction on spi_write_then_read() · b3a223ee
      Mark Brown 提交于
      In order to avoid constantly allocating and deallocating there is a fixed
      buffer which spi_write_then_read() uses for transfers, with an early error
      check to ensure that the transfer fits within the buffer. This limits the
      size of transfers to this size, currently max(32, SMP_CACHE_BYTES).
      
      Since we can dynamically allocate and in fact already have a fallback
      to do so when there is contention for the fixed buffer remove this
      restriction and instead dynamically allocate a suitably sized buffer if
      the transfer won't fit.
      Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      b3a223ee
  2. 22 11月, 2012 1 次提交
  3. 10 11月, 2012 2 次提交
  4. 21 5月, 2012 1 次提交
  5. 20 5月, 2012 1 次提交
  6. 11 5月, 2012 1 次提交
  7. 14 4月, 2012 1 次提交
  8. 15 3月, 2012 1 次提交
  9. 11 3月, 2012 1 次提交
  10. 10 3月, 2012 2 次提交
  11. 08 3月, 2012 1 次提交
    • L
      spi: create a message queueing infrastructure · ffbbdd21
      Linus Walleij 提交于
      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: NChris Blair <chris.blair@stericsson.com>
      Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
      Tested-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      ffbbdd21
  12. 14 12月, 2011 1 次提交
  13. 01 11月, 2011 1 次提交
  14. 06 6月, 2011 1 次提交
  15. 20 5月, 2011 1 次提交
  16. 31 3月, 2011 1 次提交
  17. 25 12月, 2010 1 次提交
  18. 23 12月, 2010 1 次提交
  19. 22 10月, 2010 2 次提交
  20. 03 10月, 2010 1 次提交
  21. 01 9月, 2010 1 次提交
  22. 30 7月, 2010 1 次提交
  23. 29 6月, 2010 1 次提交
    • E
      spi/mmc_spi: SPI bus locking API, using mutex · cf32b71e
      Ernst Schwab 提交于
      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: NErnst Schwab <eschwab@online.de>
      [grant.likely@secretlab.ca: use spin_lock_irqsave()]
      Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      Tested-by: NMatt Fleming <matt@console-pimps.org>
      Tested-by: NAntonio Ospite <ospite@studenti.unina.it>
      cf32b71e
  24. 28 4月, 2010 2 次提交
  25. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      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: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  26. 23 9月, 2009 3 次提交
    • D
      spi: handle TX-only/RX-only · 568d0697
      David Brownell 提交于
      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 <m.szyprowski@samsung.com>
      Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      568d0697
    • A
      spi: prefix modalias with "spi:" · e0626e38
      Anton Vorontsov 提交于
      This makes it consistent with other buses (platform, i2c, vio, ...).  I'm
      not sure why we use the prefixes, but there must be a reason.
      
      This was easy enough to do it, and I did it.
      Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Jean Delvare <khali@linux-fr.org>
      Cc: Ben Dooks <ben-linux@fluff.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Dmitry Torokhov <dtor@mail.ru>
      Cc: Samuel Ortiz <sameo@openedhand.com>
      Cc: "John W. Linville" <linville@tuxdriver.com>
      Acked-by: NMike Frysinger <vapier.adi@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e0626e38
    • A
      spi: add support for device table matching · 75368bf6
      Anton Vorontsov 提交于
      With this patch spi drivers can use standard spi_driver.id_table and
      MODULE_DEVICE_TABLE() mechanisms to bind against the devices.  Just like
      we do with I2C drivers.
      
      This is useful when a single driver supports several variants of devices
      but it is not possible to detect them in run-time (like non-JEDEC chips
      probing in drivers/mtd/devices/m25p80.c), and when platform_data usage is
      overkill.
      
      This patch also makes life a lot easier on OpenFirmware platforms, since
      with OF we extensively use proper device IDs in modaliases.
      Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Jean Delvare <khali@linux-fr.org>
      Cc: Ben Dooks <ben-linux@fluff.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      75368bf6
  27. 19 6月, 2009 3 次提交
  28. 14 4月, 2009 1 次提交
  29. 07 1月, 2009 1 次提交
  30. 17 10月, 2008 2 次提交
  31. 15 8月, 2008 1 次提交
    • D
      spi: bugfix spi_add_device() with duplicate chipselects · e48880e0
      David Brownell 提交于
      When reviewing a recent patch I noticed a potential trouble spot in the
      registration of new SPI devices.  The SPI master driver is told to set
      the device up before adding it to the driver model, so that it's always
      properly set up when probe() is called.  (This is important, because in
      the case of inverted chipselects, this device can make the bus misbehave
      until it's properly deselected.  It's got to be set up even if no driver
      binds to the device.)
      
      The trouble spot is that it doesn't first verify that no other device
      has been added using that chipselect.  If such a device has been added,
      its configuration gets trashed.  (Fortunately this has not been a common
      error!)
      
      The fix here adds an explicit check, and a mutex to protect the relevant
      critical region.
      
      [akpm@linux-foundation.org: make the lock local to spi_add_device()]
      Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e48880e0