system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-16 09:05:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

of/spi: Support specifying chip select as active high via device tree

Browse source 
The patch allows to specify that an SPI device needs an active high chip
select.

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Wolfgang Ocker 2008-10-15 15:00:47 +02:00 committed by Kumar Gala
parent fd657efc67
commit f618ebfcbf
2 changed files with 4 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
Documentation/powerpc/booting-without-of.txt
View file

@ -1917,6 +1917,8 @@ platforms are moved over to use the flattened-device-tree model.
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@f00 {

2
drivers/of/of_spi.c
View file

@ -61,6 +61,8 @@ void of_register_spi_devices(struct spi_master *master, struct device_node *np)
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);