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| author | Thierry Reding <treding@nvidia.com> | 2014-01-09 17:08:36 +0100 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2014-01-23 15:51:32 +0100 |
| commit | 13411ddd319057ae334a4084ebcf2c741b317f34 (patch) | |
| tree | 9915698fb7fe169acd53b9b7f75347524ed04a98 /Documentation | |
| parent | 70bf6878a874523e4b62992d07b5739298f8c1eb (diff) | |
drm/tegra: Obtain head number from DT
The head number of a given display controller is fixed in hardware and
required to program outputs appropriately. Relying on the driver probe
order to determine this number will not work, since that could yield a
situation where the second head was probed first and would be assigned
head number 0 instead of 1.
By explicitly specifying the head number in the device tree, it is no
longer necessary to rely on these assumptions. As a fallback, if the
property isn't available, derive the head number from the display
controller node's position in the device tree. That's somewhat more
reliable than the previous default but not a proper solution.
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt b/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt index 9e9008f8fa32..efaeec8961b6 100644 --- a/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt +++ b/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt @@ -118,6 +118,9 @@ of the following host1x client modules: See ../reset/reset.txt for details. - reset-names: Must include the following entries: - dc + - nvidia,head: The number of the display controller head. This is used to + setup the various types of output to receive video data from the given + head. Each display controller node has a child node, named "rgb", that represents the RGB output associated with the controller. It can take the following |