[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <200902191206.17734.mb@bu3sch.de>
Date: Thu, 19 Feb 2009 12:06:17 +0100
From: Michael Buesch <mb@...sch.de>
To: David Brownell <dbrownell@...rs.sourceforge.net>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org
Subject: [PATCH] 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@...sch.de>
---
Index: linux-2.6/include/linux/spi/spi_bitbang.h
===================================================================
--- linux-2.6.orig/include/linux/spi/spi_bitbang.h 2009-02-19 11:59:23.000000000 +0100
+++ linux-2.6/include/linux/spi/spi_bitbang.h 2009-02-19 12:04:09.000000000 +0100
@@ -83,6 +83,13 @@ extern int spi_bitbang_stop(struct spi_b
* 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).
--
Greetings, Michael.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists