[PATCH] powerpc: SPI: specify chip select active high
Grant Likely
grant.likely at secretlab.ca
Thu Oct 16 01:22:28 EST 2008
On Wed, Oct 15, 2008 at 03:00:47PM +0200, Wolfgang Ocker wrote:
> The patch allows to specify that an SPI device needs an active high chip
> select.
This look reasonable to me. Anyone else have comments on this binding?
g.
>
> 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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