On Mon, Feb 18, 2013 at 2:25 PM, Sylwester Nawrocki <sylvester.nawro...@gmail.com> wrote:
> My context was a multiprocessor SoC, where one of the processors is somehow > application specific (e.g. camera ISP) and can be considered as a slave > subsystem, running it's firmware and sharing system memory with the main > processor. > > The slave subsystem can have insane constraints on the memory region where > its firmware is located and which it also uses as its generic purpose RAM. > > While the region assigned to such a slave device would also likely include > a memory for its DMA buffers, the main concern here was an allocation of > a working memory for the slave processor. > > Perhaps the device tree is not a perfect place for defining exact memory > regions. If we happen to decide against it, then I guess some set of > properties would be needed, that would allow CMA to assign appropriate > memory region(s) to a device. The place to add such constraints are in the bindings for the camera ISP. This isn't that different from how dma-window properties used on some of the PowerPC platforms; it specifies (among other things) the available address space as seen from the bus/device side. -Olof _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss