On Wed, Apr 27, 2016 at 05:58:05PM -0600, Sagar Dharia wrote:
> OF helper routine scans the SLIMbus DeviceTree, allocates resources,
> and creates slim_devices according to the hierarchy.
>
> Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/slimbus/bus.txt | 55 ++++++++++++++++++++++
> drivers/slimbus/slim-core.c | 57 +++++++++++++++++++++++
> 2 files changed, 112 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/slimbus/bus.txt
>
> diff --git a/Documentation/devicetree/bindings/slimbus/bus.txt b/Documentation/devicetree/bindings/slimbus/bus.txt
> new file mode 100644
> index 0000000..c5bb54a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/slimbus/bus.txt
> @@ -0,0 +1,55 @@
> +SLIM(Serial Low Power Interchip Media Bus) bus
> +
> +SLIMbus is a 2-wire bus, and is used to communicate with peripheral
> +components like audio-codec.
> +
> +Controller is a normal device using binding for whatever bus it is
> +on (e.g. platform bus).
> +Required property for SLIMbus controller node:
> +- compatible - name of SLIMbus controller following generic names
> + recommended practice.
> +- #address-cells - should be 4 (number of cells required to define
> + 4 fields of the enumeration address for the SLIMbus
> + slave device)
> +- #size-cells - should be 0
> +
> +No other properties are required in the SLIMbus controller bus node.
> +
> +Child nodes:
> +Every SLIMbus controller node can contain zero or more child nodes
> +representing slave devices on the bus. Every SLIMbus slave device is
> +uniquely determined by the enumeration address containing 4 fields:
> +Manufacturer ID, Product code, Device index, and Instance value for
> +the device.
> +If child node is not present and it is instantiated after device
> +discovery (slave device reporting itself present),
> +its name will be in this format: "217:60:1:0"
> +
> +However, the device may need additional non-standard way to power it
> +up so that it can start functioning. In that case, child node will
> +need to be present as slave of the slimbus-controller device.
> +The compatible property will be necessary so that corresponding
> +driver can probe and execute the required procedure to make it
> +functional.
> +
> +Required property for SLIMbus child node if it is present:
> +- reg - enumeration address fields of the device
> +
> +- compatible - name of SLIMbus child node using practice typically
> + followed by discoverable buses:
> + "<manufacturer>,<product-model>", "slim"
Im most cases for compatible strings on discoverable buses, the VID and
PID (and perhaps more) are used to form the compatible string. See USB
binding for a recent example. This will save you from having to make up
strings for every device.
> +
> +SLIMbus example for Qualcomm's slimbus manager component:
> +
> + slim@28080000 {
> + compatible = "qcom,slim-msm";
> + reg = <0x28080000 0x2000>,
> + interrupts = <0 33 0>;
> + clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>;
> + clock-names = "iface_clk", "core_clk";
> +
> + codec@0217.0060.01.00 {
unit-addresses should use ',' to separate fields and generally don't
have leading zeros.
> + compatible = "qcom,wcdv1", "slim";
> + reg = <0x217 0x60 0x1 0x0>;
> + };
> + };
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