[U-Boot] [RFC] How to get "#address-cells" in U-Boot?

[Masahiro Yamada]

Hi.

> 
> Another question.
> 
> Can U-boot handle the address transformation?
> 
> If the upper "bus" node has "ranges" property,
> it must also be checked to get the correct base address, I think.


I take this question back too.
Sorry for noise.



> 
> On Mon, 17 Nov 2014 19:38:41 +0900
> Masahiro Yamada <yamada.m at jp.panasonic.com> wrote:
> 
> > Hi.
> > 
> > 
> > I want to decode the base address of device nodes of my device trees.
> > 
> > For example, drivers/serial/ns16550.c uses fdtdec_get_addr() function
> > to decode the "reg" property, but it is not very nice because
> > it does not check "#address-cells".
> > 
> > Precisely, we need to check the parent node to get "#address-cells".
> > (If the parent does not have it, we need to search for it towards the root node.)
> > 
> > 
> > I am looking for something like of_n_addr_cells() and of_n_size_cells() functions
> > of Linux Kernel.
> > 
> > 
> > I don't think it is feasible in U-Boot because
> > U-Boot handles device tree blobs as they are (as flattened binaries).
> > 
> > If we want to get properties of the parenet node, we must parse the DTB from the
> > beginning.  Yes, U-Boot actually parses the same DTB over and over again.
> > 
> > Any advice?   Import drivers/of/* from Linux??
> > 
> > 
> > 
> > Simon, do you have any good idea to solve this problem by DM?
> > For example, add "address_cells" and "size_cells" members to struct udevice
> > and then  modify drivers/core/simple-bus.c to parse "#address-cells" and "#size-cells"
> > and pass them to children.
> > 
> > 
> 
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot