01 Nov, 2011

1 commit


06 Jul, 2010

2 commits

  • Implement generic OF gpio hooks and thus make device-enabled GPIO chips
    (i.e. the ones that have gpio_chip->dev specified) automatically attach
    to the OpenFirmware subsystem. Which means that now we can handle I2C and
    SPI GPIO chips almost* transparently.

    * "Almost" because some chips still require platform data, and for these
    chips OF-glue is still needed, though with this change the glue will
    be much smaller.

    Signed-off-by: Anton Vorontsov
    Signed-off-by: Grant Likely
    Cc: David Brownell
    Cc: Bill Gatliff
    Cc: Dmitry Eremin-Solenikov
    Cc: Benjamin Herrenschmidt
    Cc: Jean Delvare
    Cc: Andrew Morton
    CC: linux-kernel@vger.kernel.org
    CC: devicetree-discuss@lists.ozlabs.org

    Anton Vorontsov
     
  • The OF gpio infrastructure is great for describing GPIO connections within
    the device tree. However, using a GPIO binding still requires changes to
    the gpio controller just to add an of_gpio structure. In most cases, the
    gpio controller doesn't actually need any special support and the simple
    OF gpio mapping function is more than sufficient. Additional, the current
    scheme of using of_gpio_chip requires a convoluted scheme to maintain
    1:1 mappings between of_gpio_chip and gpio_chip instances.

    If the struct of_gpio_chip data members were moved into struct gpio_chip,
    then it would simplify the processing of OF gpio bindings, and it would
    make it trivial to use device tree OF connections on existing gpiolib
    controller drivers.

    This patch eliminates the of_gpio_chip structure and moves the relevant
    fields into struct gpio_chip (conditional on CONFIG_OF_GPIO). This move
    simplifies the existing code and prepares for adding automatic device tree
    support to existing drivers.

    Signed-off-by: Grant Likely
    Cc: Andrew Morton
    Cc: Anton Vorontsov
    Cc: Grant Likely
    Cc: David Brownell
    Cc: Bill Gatliff
    Cc: Dmitry Eremin-Solenikov
    Cc: Benjamin Herrenschmidt
    Cc: Jean Delvare

    Anton Vorontsov
     

30 Mar, 2010

1 commit

  • …it 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: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

31 Dec, 2008

1 commit

  • The driver supports very simple GPIO controllers, that is, when a
    controller provides just a 'data' register. Such controllers may be
    found in various BCSRs (Board's FPGAs used to control board's
    switches, LEDs, chip-selects, Ethernet/USB PHY power, etc).

    So far we support only 1-byte GPIO banks. Support for other widths may
    be implemented when/if needed.

    p.s.
    To avoid "made up" compatible entries (like compatible = "simple-gpio"),
    boards must call simple_gpiochip_init() to pass the compatible string.

    Signed-off-by: Anton Vorontsov
    Signed-off-by: Kumar Gala

    Anton Vorontsov