[PATCH v3 1/2] dt: bindings: mmc: Add sdio function subnode documentation
From: Hans de Goede <hidden>
Date: 2014-06-03 08:11:28
Also in:
linux-arm-kernel, linux-mmc
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, open firmware and flattened device tree bindings, the rest · Maintainers:
Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
From: Sascha Hauer <redacted> 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 <redacted> [hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org: Documented the need for #address- and #size-cells] [hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org: Added a real world example] Signed-off-by: Hans de Goede <redacted> --- Documentation/devicetree/bindings/mmc/mmc.txt | 48 ++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 9dce540..79b222f 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt@@ -60,7 +60,31 @@ Optional SDIO properties: - keep-power-in-suspend: Preserves card power during a suspend/resume cycle - enable-sdio-wakeup: Enables wake up of host system on SDIO IRQ assertion -Example: + +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 host controller node. +The subnodes are identified by the standard 'reg' property. +Which information exactly can be specified depends on the bindings for the +SDIO function driver for the subnode, as specified by the compatible string. + +Required host node 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 +-------- + +Basic example: sdhci@ab000000 { compatible = "sdhci";
@@ -74,3 +98,25 @@ sdhci@ab000000 { keep-power-in-suspend; enable-sdio-wakeup; } + +Example with sdio function subnode: + +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"; + + brcmf: bcrmf@1 { + reg = <1>; + compatible = "brcm,bcm43xx-fmac"; + interrupt-parent = <&pio>; + interrupts = <10 8>; /* PH10 / EINT10 */ + interrupt-names = "host-wake"; + }; +};
--
2.0.0