From: Michael Buesch Date: Fri, 20 Feb 2009 23:38:49 +0000 (-0800) Subject: spi_bitbang: add more lowlevel function documentation X-Git-Tag: v2.6.29-rc6~22 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=01b24fee285b098c74318a8be801ef3711ec18d7;p=~shefty%2Frdma-dev.git spi_bitbang: add more lowlevel function documentation This adds more documentation of the lowlevel API to avoid future bugs. Signed-off-by: Michael Buesch Acked-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h index bf8de281b4e..eed4254bd50 100644 --- a/include/linux/spi/spi_bitbang.h +++ b/include/linux/spi/spi_bitbang.h @@ -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).