path: root/Documentation
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authorMike Frysinger <vapier@gentoo.org>2011-07-22 23:10:11 -0400
committerMike Frysinger <vapier@gentoo.org>2011-07-23 01:18:35 -0400
commit10617340ce1491da7654d408d0d635ba98ef8350 (patch)
treecff62989a8d5c0d8b0961bdd96c5e07297261182 /Documentation
parent2b6678c552ea05e7732fa1486ae1f56cb4a45f47 (diff)
Blackfin: spi-docs: further clarify GPIO CS behavior with various modes
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'Documentation')
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/blackfin/bfin-spi-notes.txt b/Documentation/blackfin/bfin-spi-notes.txt
index 556fa877f2e8..eae6eaf2a09d 100644
--- a/Documentation/blackfin/bfin-spi-notes.txt
+++ b/Documentation/blackfin/bfin-spi-notes.txt
@@ -9,6 +9,8 @@ the entire SPI transfer. - And not just bits_per_word duration.
In most cases you can utilize SPI MODE_3 instead of MODE_0 to work-around this
behavior. If your SPI slave device in question requires SPI MODE_0 or MODE_2
timing, you can utilize the GPIO controlled SPI Slave Select option instead.
+In this case, you should use GPIO based CS for all of your slaves and not just
+the ones using mode 0 or 2 in order to guarantee correct CS toggling behavior.
You can even use the same pin whose peripheral role is a SSEL,
but use it as a GPIO instead.

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