From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
While SDIO devices are runtime probable they sometimes need nonprobable
additional information on embedded systems, like an additional gpio
interrupt or a clock. This binding describes how to add child nodes to the
devicetree to supply this information.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
[hdegoede@xxxxxxxxxx: Updated the bindings to put the sdio functions inside
slot subnodes]
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Documentation/devicetree/bindings/mmc/mmc.txt | 49 +++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 44c9e53..2903775 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -81,6 +81,27 @@ if a property is specified at both the host and the slot level the slot
level takes precedence.
+Use of Function subnodes
+------------------------
+
+On embedded systems the cards connected to a host may need additional
+properties. These can be specified in subnodes to the slot subnodes, with
+the card / SDIO-function identified by the standard 'reg' property.
+Note that the use of slot subnodes is mandatory in this case.
+Which information exactly can be specified depends on the bindings for the
+SDIO function driver for the node, as specified by the compatible string.
+
+Required slot subnode properties when using function subnodes:
+- #address-cells: should be one. The cell is the slot id.
+- #size-cells: should be zero.
+
+Required function subnode properties:
+- compatible: name of SDIO function following generic names recommended practice
+- reg: Must contain the SDIO function number of the function this subnode
+ describes. A value of 0 denotes the memory SD function, values from
+ 1 to 7 denote the SDIO functions.
+
+
Examples
--------
@@ -118,3 +139,31 @@ mmc0: mmc@f0008000 {
bus-width = <4>;
};
};
+
+Example with sdio function subnodes:
+
+mmc3: mmc@01c12000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ pinctrl-names = "default";
+ pinctrl-0 = <&mmc3_pins_a>;
+ vmmc-supply = <®_vmmc3>;
+ bus-width = <4>;
+ non-removable;
+ status = "okay";
+
+ mmc3_slot0: mmc3_slot@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0>;
+
+ brcmf: bcrmf@1 {
+ reg = <1>;
+ compatible = "brcm,bcm43xx-fmac";
+ interrupt-parent = <&pio>;
+ interrupts = <10 8>; /* PH10 / EINT10 */
+ interrupt-names = "host-wake";
+ };
+ };
+};
--
2.0.0
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