On Sat, Feb 06, 2016 at 11:44:21AM -0700, 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 | 54 ++++++++++++++++
> drivers/slimbus/slim-core.c | 75 +++++++++++++++++++++++
> 2 files changed, 129 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..71c769d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/slimbus/bus.txt
> @@ -0,0 +1,54 @@
> +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.
> +
> +Required property for SLIMbus child node:
> +- reg - enumeration address fields of the device
> +
> +Optional:
> +- compatible - Slave devices can use compatible field to have a name.
> + If this field is missing, name of the device will be
> + determined using slave's enumeration address.
> + (e.g. in the example below, slave's name will be:
> + 0x217:0x60:0x1:0x0)
The compatible string should follow other discoverable buses like PCI
and USB and use the enumeration data for the compatible string.
Something like "slim<manuID>,<product code>".
> + Note that the property is listed as optional since the
> + devices are discoverable when they are functional.
> + However, the device may need additional non-standard
> + way to power it up so that it can start functioning.
> + In that case, compatible property will be
> + needed for the corresponding driver to probe and
> + perform the required procedure to make it functional.
I think the node being present should be optional, but the compatible
should be required if node is present.
> +
> +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_slave@0217.0060.01.00 {
Unique fields should be separated by commas.
Probably should just be "codec@..."
> + reg = <0x217 0x60 0x1 0x0>;
> + };
> + };
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