On Thu, Jun 27, 2013 at 9:22 PM, Mr. Robert G Palmer Jr. <robert.pal...@ingenutec.com> wrote: > I apologize up front if this is the wrong place for these questions. I'm > relatively new to the OF Device Tree. If this is the wrong place, would > someone point me to the correct discussion location. > > 1. Is it possible to take an existing kernel build that uses a board file > move only a small portion into a Device Tree. I am working on converting a > driver from supporting only the board file to supporting both the board file > and the OF Device Tree. Unfortunately, the only test platform I have with > the appropriate hardware is a Nexus7 and I'm using the Cyanogenmod build. > This uses (or at least appears to use) a board file for the Nexus7. Is it > possible to write a small Device Tree description for only the driver I am > working on? Where would this device tree file be placed? How would I > include it in the build? Any assistance and/or pointers would be > appreciated.
Yes. Enable CONFIG_OF and add a dt_compat pointer to the existing nexus7 MACHINE_START() stanze. Then a trivial device tree with a top-level compatible property that matches something in the dt_compat table can be used to boot the platform. arch/arm/mach-versatile/versatile_dt.c shows an example. > 2. Are there any suggestions or hints for searching for OF Device Tree > information. The term "device tree" is used pervasively in the linux code > and various projects to refer to source branches of a particular device type > rather than the OF Device Tree. This makes it extremely difficult to > isolate applicable answers. This link is useful: http://devicetree.org/Device_Tree_Usage Also, look at the files in Documentation/devicetree in the Linux kernel. g. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
