[PATCH 2/2] spi: devicetree: add support for loopback mode

[Felipe Balbi]

there are a few spi master drivers which make
use of that flag but there is no way to pass it
through devicetree.

This patch just creates a way to pass SPI_LOOP
via devicetree.

Signed-off-by: Felipe Balbi <balbi at ti.com>
---
 Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++
 drivers/spi/spi.c                                 | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 296015e..1949586 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -55,6 +55,8 @@ contain the following properties.
     		chip select active high
 - spi-3wire       - (optional) Empty property indicating device requires
     		    3-wire mode.
+- spi-loopback    - (optional) Empty property indicating device requires
+    		    loopback mode.
 
 If a gpio chipselect is used for the SPI slave the gpio number will be passed
 via the cs_gpio
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 3f1b9ee..6bcdc03 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -868,6 +868,8 @@ static void of_register_spi_devices(struct spi_master *master)
 			spi->mode |= SPI_CS_HIGH;
 		if (of_find_property(nc, "spi-3wire", NULL))
 			spi->mode |= SPI_3WIRE;
+		if (of_find_property(nc, "spi-loopback", NULL))
+			spi->mode |= SPI_LOOP;
 
 		/* Device speed */
 		prop = of_get_property(nc, "spi-max-frequency", &len);
-- 
1.8.1.rc1.5.g7e0651a