[U-Boot] [PATCH 05/12] aspeed/ast2500: Device Tree and bindings for some of the clocks

Maxim Sloyko
2017-01-17T23:27:09Z

On Sat, Jan 14, 2017 at 9:13 AM, Simon Glass <sjg@chromium.org> wrote:

> Hi Maxim,
>
> On 5 January 2017 at 15:20, Maxim Sloyko <maxims@google.com> wrote:
> > On Wed, Jan 4, 2017 at 7:26 PM, Tom Rini <trini@konsulko.com> wrote:
> >> On Wed, Jan 04, 2017 at 05:18:42PM -0800, Maxim Sloyko wrote:
> >>> On Wed, Jan 4, 2017 at 12:58 PM, Tom Rini <trini@konsulko.com> wrote:
> >>> > On Wed, Jan 04, 2017 at 11:46:49AM -0800, Maxim Sloyko wrote:
> >>> >
> >>> >> Signed-off-by: Maxim Sloyko <maxims@google.com>
> >>> >> ---
> >>> >>
> >>> >> arch/arm/dts/ast2500.dtsi | 423
> ++++++++++++++++++++++++++++++++
> >>> >> include/dt-bindings/clock/ast2500-scu.h | 29 +++
> >>> >> 2 files changed, 452 insertions(+)
> >>> >> create mode 100644 arch/arm/dts/ast2500.dtsi
> >>> >> create mode 100644 include/dt-bindings/clock/ast2500-scu.h
> >>> >>
> >>> >> diff --git a/arch/arm/dts/ast2500.dtsi b/arch/arm/dts/ast2500.dtsi
> >>> >> new file mode 100644
> >>> >> index 0000000000..1a2a3f7ee3
> >>> >> --- /dev/null
> >>> >> +++ b/arch/arm/dts/ast2500.dtsi
> >>> >> @@ -0,0 +1,423 @@
> >>> >> +/* This device tree is copied from
> >>> >> + * https://github.com/openbmc/linux/blob/c5682cb/arch/arm/
> boot/dts/aspeed-g5.dtsi
> >>> >
> >>> > Is this also found in the Linux kernel or not yet? Thanks!
> >>>
> >>> Yes, this is also in in main Linux kernel now, as I've found out, but
> >>> actually there is a number of differences, most notably there is no
> >>> pin configuration in this device tree, because there is no pinctrl
> >>> driver.
> >
> > Actually, I take that back, I was looking at the wrong linux Linux
> > kernel tree still... Only basic version of device tree has made it to
> > mainline kernel, but it's enough at the moment, so I used that
> > instead.
> >
> >>>
> >>> Should I remove this reference or modify it?
> >>
> >> Ideally, we will take the kernel dts files and then add what we need on
> >> top of that in one of CONFIG_SYS_CPU/CONFIG_SYS_SOC/CONFIG_SYS_VENDOR
> >> -u-boot.dtsi files, see for example arch/arm/dts/sunxi-u-boot.dtsi or
> >> arch/arm/dts/tegra124-nyan-big-u-boot.dtsi
> >
> > OK, so I took the device tree from the Linux kernel, (ast2500.dtsi),
> > added modifications in ast2500-u-boot.dtsi and now include
> > ast2500-u-boot.dtsi in ast2500-evb.dts. Let me know if I misunderstood
> > you.
>
> There is some magic in the Makefile which automatically includes the
> .dtsi if you name it correctly:
>
> # Try these files in order to find the U-Boot-specific .dtsi include file
> u_boot_dtsi_options = $(wildcard $(dts_dir)/$(basename $(notdir
> $<))-u-boot.dtsi) \
> $(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_SOC))-u-boot.dtsi) \
> $(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_CPU))-u-boot.dtsi) \
> $(wildcard $(dts_dir)/$(subst $\",,$(CONFIG_SYS_VENDOR))-u-boot.dtsi) \
> $(wildcard $(dts_dir)/u-boot.dtsi)
>
>
> So you should not need to include it explicitly.
>

Well, it looks like the only applicable for this case would be
CONFIG_SYS_SOC, but it looks like this setting also affects the mach- and
arch- directories used. In this case I want different aspeed SoCs to share
those directories, but
they will have different DTs.

>
> Regards,
> Simon
>

--
*M*axim *S*loyko