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

From: Felipe Balbi
Date: Wed Dec 12 2012 - 03:53:11 EST


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@xxxxxx>
---
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

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