Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c20151df authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Grant Likely
Browse files

spi: Add support for specifying 3-wire mode via device tree 



This patch allows to specify that a SPI device is connected in 3-wire mode via
device tree.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 5323f498

Documentation/devicetree/bindings/spi/spi-bus.txt

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ contain the following properties. 
    		shifted clock phase (CPHA) mode

- spi-cs-high     - (optional) Empty property indicating device requires

    		chip select active high

- spi-3wire       - (optional) Empty property indicating device requires

    		    3-wire mode.



If a gpio chipselect is used for the SPI slave the gpio number will be passed

via the cs_gpio

drivers/spi/spi.c

+2 −0
Original line number Diff line number Diff line
@@ -861,6 +861,8 @@ static void of_register_spi_devices(struct spi_master *master) 
			spi->mode |= SPI_CPOL;

		if (of_find_property(nc, "spi-cs-high", NULL))

			spi->mode |= SPI_CS_HIGH;

		if (of_find_property(nc, "spi-3wire", NULL))

			spi->mode |= SPI_3WIRE;



		/* Device speed */

		prop = of_get_property(nc, "spi-max-frequency", &len);