1. 12 10月, 2008 1 次提交
  2. 22 9月, 2008 2 次提交
  3. 05 8月, 2008 1 次提交
  4. 26 7月, 2008 1 次提交
    • 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
  5. 27 6月, 2008 1 次提交
  6. 06 2月, 2008 1 次提交
    • D
      gpiolib: avr32 at32ap platform support · b98348bd
      David Brownell 提交于
      Teach AVR32 to use the "GPIO Library" when exposing its GPIOs, so that signals
      on external chips (like GPIO expanders) can easily be used.
      
      This mostly reorganizes some existing logic, with two minor changes in
      behavior:
      
       - The PSR registers are used instead of the previous "gpio_mask" values,
         matching AT91 behavior and removing some duplication between that role
         and that of "pinmux_mask".
      
       - NR_IRQs grew to acommodate a bank of external GPIOs.  Eventually this
         number should probably become a board-specific config option.
      
      There's a debugfs dump of status for the built-in GPIOs, showing which pins
      have deglitching, pullups, or open drain drive enabled, as well as the ID
      string used when requesting each IRQ.
      Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
      Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
      Cc: Jean Delvare <khali@linux-fr.org>
      Cc: Eric Miao <eric.miao@marvell.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Cc: Philipp Zabel <philipp.zabel@gmail.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ben Gardner <bgardner@wabtec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b98348bd
  7. 11 10月, 2007 1 次提交
  8. 17 3月, 2007 1 次提交
  9. 09 2月, 2007 3 次提交
  10. 08 12月, 2006 1 次提交
  11. 26 9月, 2006 1 次提交