[PATCH] SPI: Set SPI bits per words in an OF DeviceTree SPI node

[PATCH] SPI: Set SPI bits per words in an OF DeviceTree SPI node

[Christophe Leroy]

This patch allows to set up the bits per word together with all other SPI
parameters in the SPI Node of the OF device tree

In the node, you then have to include the 'spi-bits' property.

Exemple:
	fpga-loader@7 {
		compatible = "cs,fpga-loader";
		spi-max-frequency = <10000000>;
		reg = <7>;
		spi-cs-high;
		spi-bits = <16>;
	};

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

--- linux-3.8.13/drivers/spi/spi.c	2013-05-11 22:57:46.000000000 +0200
+++ linux/drivers/spi/spi.c	2013-08-06 18:19:30.000000000 +0200
@@ -870,6 +870,11 @@
 		if (of_find_property(nc, "spi-3wire", NULL))
 			spi->mode |= SPI_3WIRE;
 
+		/* Bits per word */
+		prop = of_get_property(nc, "spi-bits", &len);
+		if (prop && len >= sizeof(*prop))
+			spi->bits_per_word = prop[0];
+
 		/* Device speed */
 		prop = of_get_property(nc, "spi-max-frequency", &len);
 		if (!prop || len < sizeof(*prop)) {