Re: [PATCH v7 02/13] dt-bindings: Add SLIMbus bindings

[Vinod Koul]

On Wed, Nov 15, 2017 at 02:10:32PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> 
> SLIMbus (Serial Low Power Interchip Media Bus) is a specification
> developed by MIPI (Mobile Industry Processor Interface) alliance.
> SLIMbus is a 2-wire implementation, which is used to communicate with
> peripheral components like audio-codec.
> 
> This patch adds device tree bindings for the slimbus.
> 
> Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/slimbus/bus.txt | 50 +++++++++++++++++++++++
>  1 file changed, 50 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 000000000000..413b5076858e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/slimbus/bus.txt
> @@ -0,0 +1,50 @@
> +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.
> +
> +Required property for SLIMbus controller node:
> +- compatible	- name of SLIMbus controller
> +
> +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).

So you allow the devices to work even if the respective firmware description
is absent?

> +
> +In some cases it may be necessary to describe non-probeable device
> +details such as non-standard ways of powering up a device. In
> +such cases, child nodes for those devices will be present as
> +slaves of the slimbus-controller, as detailed below.
> +
> +Required property for SLIMbus child node if it is present:
> +- reg		- Should be ('Device index', 'Instance ID') from SLIMbus
> +		  Enumeration  Address.
> +		  Device Index Uniquely identifies multiple Devices within
> +		  a single Component.
> +		  Instance ID Is for the cases where multiple Devices of the
> +		  same type or Class are attached to the bus.
> +
> +- compatible	-"slimMID,PID". The textual representation of Manufacturer ID,
> +	 	  Product Code, shall be in lower case hexadecimal with leading
> +		  zeroes suppressed
> +
> +SLIMbus example for Qualcomm's slimbus manager component:
> +
> +	slim@28080000 {
> +		compatible = "qcom,apq8064-slim", "qcom,slim";
> +		reg = <0x28080000 0x2000>,
> +		interrupts = <0 33 0>;
> +		clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>;
> +		clock-names = "iface", "core";
> +		#address-cells = <2>;
> +		#size-cell = <0>;
> +
> +		codec: wcd9310@1,0{
> +			compatible = "slim217,60";
> +			reg = <1 0>;
> +		};
> +	};

Pardon my ignorance as I am not very familiar with DT nodes, but where are
the Manufacturer ID, Product code, Device index, and Instance values here?

-- 
~Vinod