Add a debugfs interface for sending commands to the OLPC Embedded Controller (EC) and reading the responses. The EC provides functionality for machine identification, battery and AC control, wakeup control, etc. Having a debugfs interface available is useful for EC development and debugging. Based on code by Paul Fox (who also approves of the end result). Signed-off-by: Daniel Drake <dsd@laptop.org> Acked-by: Paul Fox <pgf@laptop.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andres Salomon <dilinger@queued.net> Link: http://lkml.kernel.org/r/20120327150740.667D09D401E@zog.reactivated.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
		
			
				
	
	
		
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What:		/sys/kernel/debug/olpc-ec/cmd
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Date:		Dec 2011
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KernelVersion:	3.4
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Contact:	devel@lists.laptop.org
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Description:
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A generic interface for executing OLPC Embedded Controller commands and
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reading their responses.
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To execute a command, write data with the format: CC:N A A A A
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CC is the (hex) command, N is the count of expected reply bytes, and A A A A
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are optional (hex) arguments.
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To read the response (if any), read from the generic node after executing
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a command. Hex reply bytes will be returned, *whether or not* they came from
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the immediately previous command.
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