On 5/12/20 11:08 AM, Pierre-Louis Bossart wrote:
On 5/12/20 10:59 AM, Vinod Koul wrote:
On 12-05-20, 09:36, Pierre-Louis Bossart wrote:
On 5/11/20 10:30 PM, Vinod Koul wrote:
On 11-05-20, 14:00, Pierre-Louis Bossart wrote:
> + md = &bus->md; > + md->dev.bus = &sdw_bus_type; > + md->dev.type = &sdw_master_type; > + md->dev.parent = parent; > + md->dev.of_node = parent->of_node; > + md->dev.fwnode = fwnode; > + md->dev.dma_mask = parent->dma_mask; > + > + dev_set_name(&md->dev, "sdw-master-%d", bus->link_id);
This give nice sdw-master-0. In DT this comes from reg property. I dont seem to recall if the ACPI/Disco spec treats link_id as unique across the system, can you check that please, if not we would need to update this.
Table 3 in the Disco for Soundwire 1.0 spec: "all LinkID values are relative to the immediate parent Device."
There isn't any known implementation with more than one controller.
But then it can come in "future" right. So lets try to make it future proof by not using the link_id (we can expose that as a sysfs if people want to know). So a global unique id needs to allocated (hint: idr or equivalent) and used as master_id
Can you clarify if you are asking for a global ID for Intel/ACPI platforms, or for DT as well? I can't figure out from the soundwire-controller.yaml definitions if there is already a notion of unique ID.
If ACPI was unique, then I was planning to update the definition below to include that. Given that it is not the case, let's make it agnostic to underlying firmware.
I am not sure I understand how this would be done.
The call sequence is
sdw_bus_master_add(bus) sdw_master_device_add(bus, parent, fw_node)
At the bus level, we don't have any information on which controller the bus is related to.
We'd need to add an argument to sdw_bus_master_add() and have the controller unique ID be allocated outside of the SoundWire core, hence my question on whether the DT definition should not be extended.
And btw I don't think it makes sense to add a new definition for Intel. We already have a notion of HDaudio bus->idx that's set to zero since we don't have a case for multiple HDaudio controllers.
if we ever do have more than once controller, then we should rely on HDaudio bus->idx as the identifier and not create one specifically for SoundWire - which means as I mentioned above passing an argument and not defining a controller ID in the SoundWire core.