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Commit 01b24fee authored by Michael Buesch's avatar Michael Buesch Committed by Linus Torvalds
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spi_bitbang: add more lowlevel function documentation 



This adds more documentation of the lowlevel API to avoid future bugs.

Signed-off-by: default avatarMichael Buesch <mb@bu3sch.de>
Acked-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f6fcba70

include/linux/spi/spi_bitbang.h

+7 −0
Original line number Diff line number Diff line
@@ -83,6 +83,13 @@ extern int spi_bitbang_stop(struct spi_bitbang *spi); 
 *  int getmiso(struct spi_device *);

 *  void spidelay(unsigned);

 *

 * setsck()'s is_on parameter is a zero/nonzero boolean.

 *

 * setmosi()'s is_on parameter is a zero/nonzero boolean.

 *

 * getmiso() is required to return 0 or 1 only. Any other value is invalid

 * and will result in improper operation.

 *

 * A non-inlined routine would call bitbang_txrx_*() routines.  The

 * main loop could easily compile down to a handful of instructions,

 * especially if the delay is a NOP (to run at peak speed).