[PATCH u-boot-dm v2] fdt_support: Add fdt_for_each_node_by_compatible() helper macro

[Simon Glass]

Hi Marek,

On Wed, 12 Jan 2022 at 15:24, Marek Behún <kabel at kernel.org> wrote:
>
> On Wed, 12 Jan 2022 13:04:08 -0700
> Simon Glass <sjg at chromium.org> wrote:
>
> > Hi Marek,
> >
> > On Mon, 10 Jan 2022 at 03:46, Marek Behún <kabel at kernel.org> wrote:
> > >
> > > From: Marek Behún <marek.behun at nic.cz>
> > >
> > > Add macro fdt_for_each_node_by_compatible() to allow iterating over
> > > fdt nodes by compatible string.
> > >
> > > Convert various usages of
> > >     off = fdt_node_offset_by_compatible(fdt, start, compat);
> > >     while (off > 0) {
> > >         code();
> > >         off = fdt_node_offset_by_compatible(fdt, off, compat);
> > >     }
> > > and similar, to
> > >     fdt_for_each_node_by_compatible(off, fdt, start, compat)
> > >         code();
> > >
> > > Signed-off-by: Marek Behún <marek.behun at nic.cz>
> > > Reviewed-by: Stefan Roese <sr at denx.de>
> > > ---
> > > Simon, as in v1, this applies on top of marvell/next and we have another
> > > patch for marvell/next that depends on this.
> > > Could we let him apply it there after it is reviewed?
> > > Thanks.
> > >
> > > Changes since v1:
> > > - removed extra space after macro name:
> > >     fdt_for_each_node_by_compatible (...)
> > >   to
> > >     fdt_for_each_node_by_compatible(...)
> > >   as requested by Stefan
> > > ---
> > >  arch/arm/cpu/armv8/fsl-layerscape/fdt.c    |  9 ++-------
> > >  arch/arm/cpu/armv8/fsl-layerscape/icid.c   |  5 +----
> > >  arch/arm/mach-tegra/gpu.c                  |  5 +----
> > >  arch/mips/mach-octeon/octeon_fdt.c         | 11 ++---------
> > >  arch/powerpc/cpu/mpc85xx/liodn.c           |  9 ++-------
> > >  board/Marvell/octeon_ebb7304/board.c       |  9 +++------
> > >  board/congatec/cgtqmx8/spl.c               |  7 ++-----
> > >  board/freescale/lx2160a/lx2160a.c          |  5 +----
> > >  common/fdt_support.c                       | 22 ++++++++--------------
> > >  drivers/misc/fsl_portals.c                 |  6 +-----
> > >  drivers/net/fm/fdt.c                       |  3 +--
> > >  drivers/pci/pcie_layerscape_fixup_common.c | 12 ++----------
> > >  drivers/phy/marvell/comphy_a3700.c         | 10 +++++-----
> > >  drivers/video/meson/simplefb_common.c      |  7 ++-----
> > >  drivers/video/sunxi/simplefb_common.c      |  5 ++---
> > >  include/fdt_support.h                      |  6 ++++++
> > >  16 files changed, 41 insertions(+), 90 deletions(-)
> >
> > Reviewed-by: Simon Glass <sjg at chromium.org>
> >
> > In general we should not be doing this sort of thing. There should be
> > a driver for each string, so we don't need this kind of ad-hoc code.
>
> Dear Simon,
>
> you are right for when this is used for U-Boot functionality.
>
> But when we need to fixup devicetree for Linux, this is the right thing
> to do.
>
> I need this macro for ft_board_setup().

Yes, understood. I think some sort of driver interface would be nice,
perhaps using driver model. Another option would be to register
handlers using the compatible string and have a function that works
through those.

See also the event series here:

https://patchwork.ozlabs.org/project/uboot/list/?series=278607
https://lore.kernel.org/u-boot/20211228082854.1255732-1-sjg@chromium.org/

Regards,
Simon