1. 16 4月, 2013 1 次提交
  2. 12 11月, 2012 1 次提交
  3. 06 4月, 2012 1 次提交
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    • S
      Documentation/gpio.txt: Explain expected pinctrl interaction · 0dc665d4
      Stephen Warren 提交于
      Update gpio.txt based on recent discussions regarding interaction with the
      pinctrl subsystem.
      
      Previously, gpio_request() was described as explicitly not performing any
      required mux setup operations etc.
      
      Now, gpio_request() is explicitly as explicitly performing any required mux
      setup operations where possible. In the case it isn't, platform code is
      required to have set up any required muxing or other configuration prior to
      gpio_request() being called, in order to maintain the same semantics.
      
      This is achieved by gpiolib drivers calling e.g. pinctrl_request_gpio() in
      their .request() operation.
      
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Cc: linux-doc@vger.kernel.org
      Signed-off-by: NStephen Warren <swarren@nvidia.com>
      Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
      Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      0dc665d4
  5. 05 3月, 2012 1 次提交
  6. 14 1月, 2011 2 次提交
  7. 19 11月, 2010 1 次提交
  8. 10 9月, 2010 1 次提交
  9. 11 8月, 2010 1 次提交
  10. 07 3月, 2010 1 次提交
  11. 16 12月, 2009 1 次提交
  12. 10 12月, 2009 1 次提交
  13. 23 9月, 2009 2 次提交
  14. 13 6月, 2009 1 次提交
  15. 03 4月, 2009 1 次提交
  16. 17 10月, 2008 2 次提交
  17. 26 7月, 2008 2 次提交
    • M
      gpiolib: allow user-selection · 7444a72e
      Michael Buesch 提交于
      This patch adds functionality to the gpio-lib subsystem to make it
      possible to enable the gpio-lib code even if the architecture code didn't
      request to get it built in.
      
      The archtitecture code does still need to implement the gpiolib accessor
      functions in its asm/gpio.h file.  This patch adds the implementations for
      x86 and PPC.
      
      With these changes it is possible to run generic GPIO expansion cards on
      every architecture that implements the trivial wrapper functions.  Support
      for more architectures can easily be added.
      Signed-off-by: NMichael Buesch <mb@bu3sch.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: David Brownell <david-b@pacbell.net>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Jean Delvare <khali@linux-fr.org>
      Cc: Samuel Ortiz <sameo@openedhand.com>
      Cc: Kumar Gala <galak@gate.crashing.org>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Cc: Adrian Bunk <bunk@stusta.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7444a72e
    • D
      gpio: sysfs interface · d8f388d8
      David Brownell 提交于
      This adds a simple sysfs interface for GPIOs.
      
          /sys/class/gpio
          	/export ... asks the kernel to export a GPIO to userspace
          	/unexport ... to return a GPIO to the kernel
              /gpioN ... for each exported GPIO #N
      	    /value ... always readable, writes fail for input GPIOs
      	    /direction ... r/w as: in, out (default low); write high, low
      	/gpiochipN ... for each gpiochip; #N is its first GPIO
      	    /base ... (r/o) same as N
      	    /label ... (r/o) descriptive, not necessarily unique
      	    /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
      
      GPIOs claimed by kernel code may be exported by its owner using a new
      gpio_export() call, which should be most useful for driver debugging.
      Such exports may optionally be done without a "direction" attribute.
      
      Userspace may ask to take over a GPIO by writing to a sysfs control file,
      helping to cope with incomplete board support or other "one-off"
      requirements that don't merit full kernel support:
      
        echo 23 > /sys/class/gpio/export
      	... will gpio_request(23, "sysfs") and gpio_export(23);
      	use /sys/class/gpio/gpio-23/direction to (re)configure it,
      	when that GPIO can be used as both input and output.
        echo 23 > /sys/class/gpio/unexport
      	... will gpio_free(23), when it was exported as above
      
      The extra D-space footprint is a few hundred bytes, except for the sysfs
      resources associated with each exported GPIO.  The additional I-space
      footprint is about two thirds of the current size of gpiolib (!).  Since
      no /dev node creation is involved, no "udev" support is needed.
      
      Related changes:
      
        * This adds a device pointer to "struct gpio_chip".  When GPIO
          providers initialize that, sysfs gpio class devices become children of
          that device instead of being "virtual" devices.
      
        * The (few) gpio_chip providers which have such a device node have
          been updated.
      
        * Some gpio_chip drivers also needed to update their module "owner"
          field ...  for which missing kerneldoc was added.
      
        * Some gpio_chips don't support input GPIOs.  Those GPIOs are now
          flagged appropriately when the chip is registered.
      
      Based on previous patches, and discussion both on and off LKML.
      
      A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
      merges to mainline.
      
      [akpm@linux-foundation.org: a few maintenance build fixes]
      Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
      Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
      Cc: Greg KH <greg@kroah.com>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d8f388d8
  18. 28 4月, 2008 1 次提交
  19. 05 3月, 2008 1 次提交
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  27. 17 2月, 2007 1 次提交
  28. 13 2月, 2007 1 次提交
    • D
      [PATCH] GPIO core · 4c20386c
      David Brownell 提交于
      This defines a simple and minimalist programming interface for GPIO APIs:
      
        - Documentation/gpio.txt ... describes things (read it)
      
        - include/asm-arm/gpio.h ... defines the ARM hook, which just punts
          to <asm/arch/gpio.h> for any implementation
      
        - include/asm-generic/gpio.h ... implement "can sleep" variants as calling
          the normal ones, for systems that don't handle i2c expanders.
      
      The immediate need for such a cross-architecture API convention is to support
      drivers that work the same on AT91 ARM and AVR32 AP7000 chips, which embed many
      of the same controllers but have different CPUs.  However, several other users
      have been reported, including a driver for a hardware watchdog chip and some
      handhelds.org multi-CPU button drivers.
      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>
      4c20386c