mmc: atmel-mci: add device tree support

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
new file mode 100644
index 000000000000..0a85c70cd30a
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
@@ -0,0 +1,68 @@
+* Atmel High Speed MultiMedia Card Interface
+
+This controller on atmel products provides an interface for MMC, SD and SDIO
+types of memory cards.
+
+This file documents differences between the core properties described
+by mmc.txt and the properties used by the atmel-mci driver.
+
+1) MCI node
+
+Required properties:
+- compatible: should be "atmel,hsmci"
+- #address-cells: should be one. The cell is the slot id.
+- #size-cells: should be zero.
+- at least one slot node
+
+The node contains child nodes for each slot that the platform uses
+
+Example MCI node:
+
+mmc0: mmc@f0008000 {
+        compatible = "atmel,hsmci";
+        reg = <0xf0008000 0x600>;
+        interrupts = <12 4>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        [ child node definitions...]
+};
+
+2) slot nodes
+
+Required properties:
+- reg: should contain the slot id.
+- bus-width: number of data lines connected to the controller
+
+Optional properties:
+- cd-gpios: specify GPIOs for card detection
+- cd-inverted: invert the value of external card detect gpio line
+- wp-gpios: specify GPIOs for write protection
+
+Example slot node:
+
+slot@0 {
+        reg = <0>;
+        bus-width = <4>;
+        cd-gpios = <&pioD 15 0>
+        cd-inverted;
+};
+
+Example full MCI node:
+mmc0: mmc@f0008000 {
+        compatible = "atmel,hsmci";
+        reg = <0xf0008000 0x600>;
+        interrupts = <12 4>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        slot@0 {
+                reg = <0>;
+                bus-width = <4>;
+                cd-gpios = <&pioD 15 0>
+                cd-inverted;
+        };
+        slot@1 {
+                reg = <1>;
+                bus-width = <4>;
+        };
+};