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  1. 27 7月, 2008 1 次提交
  3. 26 7月, 2008 1 次提交
    • D
      gpio: sysfs interface · d8f388d8
      由 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. 15 4月, 2008 3 次提交
  7. 20 3月, 2008 1 次提交
  9. 05 3月, 2008 2 次提交
  11. 09 2月, 2008 3 次提交
  13. 25 1月, 2008 1 次提交
  15. 20 10月, 2007 1 次提交
  17. 09 5月, 2007 1 次提交
  19. 05 5月, 2007 8 次提交
  21. 22 4月, 2007 1 次提交
  23. 02 3月, 2007 1 次提交
  25. 30 11月, 2006 1 次提交
  27. 07 10月, 2006 1 次提交
  29. 25 9月, 2006 7 次提交
  31. 02 8月, 2006 1 次提交
  33. 03 7月, 2006 1 次提交
  35. 02 7月, 2006 1 次提交
  37. 01 7月, 2006 1 次提交
  39. 27 6月, 2006 2 次提交
    • I
      ARM: OMAP: Fix GPIO IRQ mask handling · 99c47707
      由 Imre Deak 提交于 
      The GPIO IRQ mask was retrieved incorrectly in cases where we have a mask
register instead of an enable register. Also we should only return the
valid bits depending on the bank size.

This fixes a bug on 1510/1610 based OMAPs where GPIO IRQs are not
delivered.
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
      99c47707
    • I
      ARM: OMAP: GPIO IRQ lazy IRQ disable fix · ea6dedd7
      由 Imre Deak 提交于 
      - The current OMAP GPIO IRQ framework doesn't use the do_edge_IRQ,
  do_level_IRQ handlers, but instead calls do_simple_IRQ. This
  doesn't handle disabled interrupts properly, so drivers will
  still get interrupts after calling disable_irq. The patch solves
  this by respecting the irq_desc.disable_depth and irq_desc.running
  counters.  When one of these is non-zero the handler is not called,
  the interrupt is masked and marked as pending. The pending interrupt
  will be serviced when the running handler returns. This is according
  to the same semantics as the standard do_edge_IRQ and do_level_IRQ
  handlers have, so one day we should use them instead of do_simple_IRQ.

- Process only interrupts that are not masked. The ISR may contain
  pending interrupts that are masked these shouldn't be processed.

- Move the bank IRQ unmasking out of the IRQ dispatch loop. If there
  are further iterations we shouldn't unmask it if there are level
  triggered interrupts pending.
Signed-off-by: NImre Deak <imre.deak@nokia.com>
Signed-off-by: NJuha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
      ea6dedd7
  41. 03 4月, 2006 1 次提交