tree 4a2ca5ca3f5937ff0ee01afa0ecbf50ddbaf39b5
parent d2d3756fa856794cfaefc963e9227a08a3044fd9
author Charlie Mooney <charliemooney@chromium.org> 1480443040 -0800
committer chrome-bot <chrome-bot@chromium.org> 1480631403 -0800

Enable Wacom FW update for Zerg systems

Previously, Wacom's firmware updater would simply look at a fixed
filename in /lib/firmware for the firmware binary when it tried to
update.  This imposes a one-wacom-device-per-build limitation since
we can't include more than one wacom fw binary per build.  As Zerg
builds (more than one device sharing a build) become more common,
we need to allow our firmware updaters to support this.  Since Wacom
doesn't support a read-only product_id like our other touch devices,
we have to make due with what we can by implimenting a similar hack
as was used to differentiate Kip and Kip+ when we made the first
Zerg build -- looking at VPD to tell which device we're on.

This CL appends the "customization_id" to the filename when looking
up the Wacom firmware filename in a similar fashion to how we use
the product_id on other devices.  If such a firmware isn't found, it
fails back to the old static filename for backwards compatability.

This relaxes the restriction from one-wacom-device-per-build to
one-wacom-device-per-customization-id, which is still more
restrictive than is ideal but is the best we can do with the hardware
at this time.

BUG=chrome-os-partner:60010
TEST=manually emerged and deployed on a non-zerg Wacom system and the
updater still works smoothly.  Similarly I tested it on Kip to make
sure it didn't regress and that VPD was loaded smoothly.

Change-Id: I780c8a0e07269b44b2ab318817d0e87789e1ce6e
Signed-off-by: Charlie Mooney <charliemooney@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/414252
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>