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author | John Klug <john.klug@multitech.com> | 2019-05-10 17:10:10 -0500 |
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committer | John Klug <john.klug@multitech.com> | 2019-05-10 17:10:10 -0500 |
commit | 4f5efcb39b25a2a9c24c36c467e7f14ce6e818a5 (patch) | |
tree | d3e4c704b655ca16f2686c7696d3dac070131a3a /README | |
download | mt-dt-overlay-4f5efcb39b25a2a9c24c36c467e7f14ce6e818a5.tar.gz mt-dt-overlay-4f5efcb39b25a2a9c24c36c467e7f14ce6e818a5.tar.bz2 mt-dt-overlay-4f5efcb39b25a2a9c24c36c467e7f14ce6e818a5.zip |
Device Tree Overlay Example1.0.0
Diffstat (limited to 'README')
-rw-r--r-- | README | 25 |
1 files changed, 25 insertions, 0 deletions
@@ -0,0 +1,25 @@ +This is the device tree overlay(s) and its make. + +The purpose of the overlay is to define the system +for the mts-io driver and/or mtac drivers. + +The correct overlay for the system is loaded at +runtime before loading the mts-io driver. A method +for doing this is the device tree configfs driver. + +See this for the format of an overlay: + +https://www.kernel.org/doc/Documentation/devicetree/overlay-notes.txt + +Note that as of 10 May 2019, no overlays have been +released. + +The biggest flaw in overlays, is the inablitiy to use +the phandle described in an alias in the boot +time device tree in an overlay, so it appears +to be impossible to reference nodes in the main +device tree in any shorthand method. For instance, it +is common to reference a "pio" in device tree to +use a PIO with GPIO. For example, it does not appear +to be possible to use &pioC in the overlay without +redefining it. |