From 13411ddd319057ae334a4084ebcf2c741b317f34 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 9 Jan 2014 17:08:36 +0100 Subject: 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 Signed-off-by: Thierry Reding --- Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt b/Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt index 9e9008f..efaeec8 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 -- cgit v1.1