spi/atmel: add DT support

Use the newly introduce cs-gpios dt support on atmel.
We do not use the hardware cs as it's wired and has bugs and limitations.
As the controller believes that only active-low devices/systems exists.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 26 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/spi/spi_atmel.txt b/Documentation/devicetree/bindings/spi/spi_atmel.txt
new file mode 100644
index 000000000000..07e04cdc0c9e
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_atmel.txt
@@ -0,0 +1,26 @@
+Atmel SPI device
+
+Required properties:
+- compatible : should be "atmel,at91rm9200-spi".
+- reg: Address and length of the register set for the device
+- interrupts: Should contain spi interrupt
+- cs-gpios: chipselects
+
+Example:
+
+spi1: spi@fffcc000 {
+        compatible = "atmel,at91rm9200-spi";
+        reg = <0xfffcc000 0x4000>;
+        interrupts = <13 4 5>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        cs-gpios = <&pioB 3 0>;
+        status = "okay";
+
+        mmc-slot@0 {
+                compatible = "mmc-spi-slot";
+                reg = <0>;
+                gpios = <&pioC 4 0>;    /* CD */
+                spi-max-frequency = <25000000>;
+        };
+};