On 23/05/18 20:28, Rob Herring wrote:
On Wed, May 23, 2018 at 1:11 PM, Srinivas Kandagatla srinivas.kandagatla@linaro.org wrote:
On 23/05/18 17:40, Rob Herring wrote:
+- qcom,ngd-id
Usage: requiredValue type: <u32>Definition: ngd instance id in the controllerWhy do you need this?
Please ignore my comment from previous reply.
There are more than one instances of ngd in this slim controller. We need this to make sure we are programming the correct one.
Doesn't the parent-child relationship of devices on the bus provide that?
Thanks for the hint, that sounds like the actual problem here, If I represent the node with proper parent-child relationship like this, it will remove the need of this property and would work perfectly in case we want to support multiple ngds in future!
slim@91c0000 { compatible = "qcom,msm8996-slim"; reg = <0x91c0000 0x2C000>; interrupts = <0 163 0>; dmas = <&slimbam 3>, <&slimbam 4>; dma-names = "rx", "tx"; #address-cells = <1>; #size-cells = <1>; ngd@1 { reg = <1>; #address-cells = <1>; #size-cells = <1>; codec@1 { compatible = "slim217,1a0"; reg = <1 0>; }; }; };
If you mean to provide consistent numbering to userspace, then
that's not a DT problem (nor one that Linux plans to solve).
No, this is not problem am trying to solve.
We also need this instance ID during powering it up using QMI.
Wouldn't that be a QMI ID?
It is passed as parameter to SLIMBUS_QMI_SELECT_INSTANCE_REQ_V01 request.
thanks, srini
Rob