On Wed, Nov 15, 2017 at 02:10:32PM +0000, srinivas.kandagatla@linaro.org wrote:
From: Sagar Dharia sdharia@codeaurora.org
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@codeaurora.org Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org
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 withina single Component.Instance ID Is for the cases where multiple Devices of thesame 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 leadingzeroes 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?