[PATCH] powerpc: SPI: specify chip select active high
Wolfgang Ocker
weo at reccoware.de
Thu Oct 16 00:00:47 EST 2008
The patch allows to specify that an SPI device needs an active high chip
select.
Signed-off-by: Wolfgang Ocker <weo at reccoware.de>
---
--- linux-2.6.27-rc7/drivers/of/of_spi.c.of_spi_cshigh 2008-09-22 00:29:55.000000000 +0200
+++ linux-2.6.27-rc7/drivers/of/of_spi.c 2008-09-29 13:43:06.000000000 +0200
@@ -61,6 +61,8 @@
spi->mode |= SPI_CPHA;
if (of_find_property(nc, "spi-cpol", NULL))
spi->mode |= SPI_CPOL;
+ if (of_find_property(nc, "spi-cs-high", NULL))
+ spi->mode |= SPI_CS_HIGH;
/* Device speed */
prop = of_get_property(nc, "spi-max-frequency", &len);
--- linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt.of_spi_cshigh 2008-09-29 14:14:08.000000000 +0200
+++ linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt 2008-09-29 14:24:26.000000000 +0200
@@ -1917,6 +1917,8 @@
inverse clock polarity (CPOL) mode
- spi-cpha - (optional) Empty property indicating device requires
shifted clock phase (CPHA) mode
+ - spi-cs-high - (optional) Empty property indicating device requires
+ chip select active high
SPI example for an MPC5200 SPI bus:
spi at f00 {
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