spi_bitbang: add more lowlevel function documentation
This adds more documentation of the lowlevel API to avoid future bugs. Signed-off-by: Michael Buesch <mb@bu3sch.de> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
f6fcba7014
commit
01b24fee28
|
@ -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).
|
||||
|
|
Loading…
Reference in a new issue