From: Mike Frysinger Date: Sat, 23 Jul 2011 03:10:11 +0000 (-0400) Subject: Blackfin: spi-docs: further clarify GPIO CS behavior with various modes X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=1061734;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git Blackfin: spi-docs: further clarify GPIO CS behavior with various modes Signed-off-by: Mike Frysinger --- 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.