Re: [PATCH v1] HID: hid-sensor-hub: Processing for duplicate physical ids

On Fri, 31 Jan 2014, Srinivas Pandruvada wrote:

In HID sensor hub, HID physical ids are used to represent different
sensors. For example physical id of 0x73 in usage page = 0x20, represents
an accelerometer. The HID sensor hub driver uses this physical ids to
create platform devices using MFD. There is 1:1 correspondence between
an phy id and a client driver.
But in some cases these physical ids are reused. There is a phy id 0xe1,
which specifies a custom sensor, which can exist multiple times to represent
various custom sensors. In this case there can be multiple instances
of client MFD drivers, processing specific custom sensor. In this
case when client driver looks for report id or a field index, it
should still get the report id specific to its own type. This is
also true for reports, they should be directed towards correct instance.
This change introduce a way to parse and tie physical devices to their
correct instance.
Summary of changes:
- To get physical ids, use collections. If a collection of type=physical
exist then use usage id as in the name of platform device name
- As part of the platform data, we assign a hdsev instance, which has
start and end of collection indexes. Using these indexes attributes
can be tied to correct MFD client instances
- When a report is received, call callback with correct hsdev instance.
In this way using its private data stored as part of its registry, it
can distinguish different sensors even when they have same physical and
logical ids.
This patch is co-authored with Archana Patni[off-list ref].

I have massaged the changelog a little bit, and applied.

-- 
Jiri Kosina
SUSE Labs