1. 12 May, 2015 2 commits
  2. 16 Mar, 2015 1 commit
  3. 05 Mar, 2015 2 commits
  4. 04 Mar, 2015 1 commit
    • Benoit Parrot's avatar
      gpio: add GPIO hogging mechanism · f625d460
      Benoit Parrot authored
      Based on Boris Brezillion's work this is a reworked patch
      of his initial GPIO hogging mechanism.
      This patch provides a way to initially configure specific GPIO
      when the GPIO controller is probed.
      The actual DT scanning to collect the GPIO specific data is performed
      as part of gpiochip_add().
      The purpose of this is to allow specific GPIOs to be configured
      without any driver specific code.
      This is particularly useful because board design are getting
      increasingly complex and given SoC pins can now have more
      than 10 mux values, a lot of connections are now dependent on
      external IO muxes to switch various modes.
      Specific drivers should not necessarily need to be aware of
      what accounts to a specific board implementation. This board level
      "description" should be best kept as part of the dts file.
      Signed-off-by: default avatarBenoit Parrot <bparrot@ti.com>
      Reviewed-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
  5. 15 Jan, 2015 1 commit
  6. 04 Nov, 2014 1 commit
    • Mika Westerberg's avatar
      gpio / ACPI: Add support for _DSD device properties · 0d9a693c
      Mika Westerberg authored
      With release of ACPI 5.1 and _DSD method we can finally name GPIOs (and
      other things as well) returned by _CRS. Previously we were only able to
      use integer index to find the corresponding GPIO, which is pretty error
      prone if the order changes.
      With _DSD we can now query GPIOs using name instead of an integer index,
      like the below example shows:
        // Bluetooth device with reset and shutdown GPIOs
        Device (BTH)
            Name (_HID, ...)
            Name (_CRS, ResourceTemplate ()
                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
                        "\\_SB.GPO0", 0, ResourceConsumer) {15}
                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
                        "\\_SB.GPO0", 0, ResourceConsumer) {27, 31}
            Name (_DSD, Package ()
                Package ()
                    Package () {"reset-gpio", Package() {^BTH, 1, 1, 0 }},
                    Package () {"shutdown-gpio", Package() {^BTH, 0, 0, 0 }},
      The format of the supported GPIO property is:
        Package () { "name", Package () { ref, index, pin, active_low }}
        ref - The device that has _CRS containing GpioIo()/GpioInt() resources,
              typically this is the device itself (BTH in our case).
        index - Index of the GpioIo()/GpioInt() resource in _CRS starting from zero.
        pin - Pin in the GpioIo()/GpioInt() resource. Typically this is zero.
        active_low - If 1 the GPIO is marked as active_low.
      Since ACPI GpioIo() resource does not have field saying whether it is
      active low or high, the "active_low" argument can be used here. Setting
      it to 1 marks the GPIO as active low.
      In our Bluetooth example the "reset-gpio" refers to the second GpioIo()
      resource, second pin in that resource with the GPIO number of 31.
      This patch implements necessary support to gpiolib for extracting GPIOs
      using _DSD device properties.
      Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      Acked-by: default avatarGrant Likely <grant.likely@linaro.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
  7. 28 Jul, 2014 1 commit
  8. 24 Jul, 2014 1 commit
  9. 23 Jul, 2014 1 commit
  10. 09 Jul, 2014 1 commit
    • Alexandre Courbot's avatar
      gpio: move sysfs support to its own file · 0eb4c6c2
      Alexandre Courbot authored
      sysfs support is currently entangled within the core GPIO support, while
      it should relly just be a (privileged) user of the integer GPIO API.
      This patch is a first step towards making the gpiolib code more readable
      by splitting it into logical parts.
      Move all sysfs support to their own source file, and share static
      members of gpiolib that need to be in the private gpiolib.h file. In
      the future we will want to put some of them back into gpiolib.c, but this
      first patch let us at least identify them.
      Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
  11. 21 May, 2014 1 commit
    • Alexandre Courbot's avatar
      gpio: make of_get_named_gpiod_flags() private · f01d9075
      Alexandre Courbot authored
      of_get_named_gpiod_flags() is visible and directly usable by GPIO
      consumers, but it really should not as the gpiod interface relies
      on the simpler gpiod_get() to provide properly-configured GPIOs.
      of_get_named_gpiod_flags() is just used internally by gpiolib to
      implement gpiod_get(), and by the old of_get_named_gpio_flags()
      function, therefore it makes sense to make it gpiolib-private.
      As a side-effect, the unused (and unneeded) of_get_gpiod_flags()
      inline function is also removed, and of_get_named_gpio_flags() is moved
      from a static inline function to a regular one in gpiolib-of.c
      This results in all references to gpiod_* functions in of_gpio.h being
      gone, which is the way it should be since this file is part of the old
      integer GPIO interface.
      Changes since v1:
      - Fixed compilation error when CONFIG_OF_GPIO is not defined
      - Fixed warning due to of_gpio_flags enum not being declared
        in private gpiolib.h header
      Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
  12. 13 Mar, 2014 1 commit
    • Mika Westerberg's avatar
      gpiolib: Allow GPIO chips to request their own GPIOs · 77c2d792
      Mika Westerberg authored
      Sometimes it is useful to allow GPIO chips themselves to request GPIOs they
      own through gpiolib API. One use case is ACPI ASL code that should be able
      to toggle GPIOs through GPIO operation regions.
      We can't use gpio_request() because it will pin the module to the kernel
      forever (it calls try_module_get()). To solve this we move module refcount
      manipulation to gpiod_request() and let __gpiod_request() handle the actual
      request. This changes the sequence a bit as now try_module_get() is called
      outside of gpio_lock (I think this is safe, try_module_get() handles
      serialization it needs already).
      Then we provide gpiolib internal functions gpiochip_request/free_own_desc()
      that do the same as gpio_request() but don't manipulate module refrence
      count. This allows the GPIO chip driver to request and free descriptors it
      owns without being pinned to the kernel forever.
      Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Reviewed-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
  13. 08 Jan, 2014 2 commits