Re: [PATCH 0/9] riscv: ultrarisc: add DP1000 SoC DT and pinctrl support

[Jia Wang]

On 2026-05-15 11:05 +0100, Conor Dooley wrote:
> Hey,
> 
> On Fri, May 15, 2026 at 09:17:56AM +0800, Jia Wang wrote:
> > This series adds initial Devicetree support for the UltraRISC DP1000 RISC-V
> > SoC and two DP1000-based boards (Milk-V Titan and Rongda M0).
> > 
> > The series introduces the required DT bindings, adds the DP1000 pinctrl
> > driver, and provides the initial SoC/board DTS files.
> > 
> > Notes:
> >   - Clocks are configured and enabled by firmware before Linux boots. Linux
> >     does not manage clock rates or gating at runtime on this platform.
> >     Therefore the initial DT only models the fixed clocks required by
> >     standard drivers, and no clock controller/driver is provided.
> 
> I really disagree with this approach. In my experience it never ends up
> working out and ends up being disruptive, because it is either an over
> simplification of the clock tree and condenses multiple different clocks
> into one where rates are similar or because firmware changes mean clock
> rate changes down the line. I would much rather you modelled the clocks
> accurately, even if that just means that a read-only clock controller is
> implemented. Alternatively, if firmware does all of your clock control,
> you can implement this using rpmi/mpoxy using clk-rpmi.c
> 

Understood. I'll implement a read-only clock controller in v2.

> >   - The DP1000 pinctrl binding supports two child node styles under the same
> >     controller compatible:
> >       * legacy DP1000-specific nodes using phandle-array properties
> >         "pinctrl-pins" and "pinconf-pins"
> >       * generic pinctrl nodes using "pins", "function" and generic pin
> >         configuration properties
> >     The legacy form is kept for compatibility with existing vendor DTs.
> 
> Why would we want "legacy" stuff in mainline when this is a brand new
> platform? "legacy" vendor devicetrees are not something that mainline
> cares about, sorry.
> 

I'll drop the legacy pinctrl node format and keep only the generic pinctrl
bindings in v2.

> Additionally, these pinctrl patches should be sent standalone to the
> pinctrl maintainers, they're likely to go through lots of revisions and
> a different maintainer applies them.
> 

Just to confirm — for v2, should I completely remove the pinctrl
binding/driver from this series and send them as a standalone pinctrl
series, while keeping only the pinctrl references in the DTS?

> >   - The bindings for "ultrarisc,dp1000-uart" and "ultrarisc,dp1000-pcie" are
> >     being reviewed in separate series, since the DP1000 SoC DTS introduced
> >     here uses those compatibles:
> >     * Link: https://lore.kernel.org/lkml/20260429-ultrarisc-serial-v7-3-e475cce9e274@xxxxxxxxxxxxx/
> >     * Link: https://lore.kernel.org/lkml/20260427-ultrarisc-pcie-v4-2-98935f6cdfb5@xxxxxxxxxxxxx/
> >   - ARCH_ULTRARISC support is being reviewed separately:
> >     * Link: https://lore.kernel.org/lkml/20260427-ultrarisc-pcie-v4-1-98935f6cdfb5@xxxxxxxxxxxxx/
> 
> IMO, this patch needs to be in this series so that it compiles.
> 

I’ll move the ARCH_ULTRARISC Kconfig patch into this series. Thanks for
pointing this out.

> Cheers,
> Conor.
> 

Best Regards,
Jia Wang

> > 
> > Testing:
> >   - dt_binding_check and yamllint (all new/modified binding YAMLs)
> >   - dtbs_check and dtbs (RISC-V, including dp1000-milkv-titan.dtb and
> >     dp1000-rongda-m0.dtb)
> >   - Kernel build for RISC-V and boot-tested on DP1000 (Milk-V Titan and
> >     Rongda M0)
> > 
> > Signed-off-by: Jia Wang <wangjia@xxxxxxxxxxxxx>
> > ---
> > Jia Wang (9):
> >       dt-bindings: vendor-prefixes: add Rongda
> >       dt-bindings: riscv: cpus: Add UltraRISC CP100 compatible
> >       dt-bindings: riscv: Add UltraRISC DP1000 bindings
> >       dt-bindings: pinctrl: Add UltraRISC DP1000 pinctrl bindings
> >       riscv: dts: ultrarisc: Add initial device tree for UltraRISC DP1000
> >       pinctrl: ultrarisc: Add UltraRISC DP1000 pinctrl driver
> >       riscv: dts: ultrarisc: add Rongda M0 board device tree
> >       riscv: dts: ultrarisc: add Milk-V Titan board device tree
> >       riscv: defconfig: enable ARCH_ULTRARISC
> > 
> >  .../bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml | 168 ++++
> >  Documentation/devicetree/bindings/riscv/cpus.yaml  |   1 +
> >  .../devicetree/bindings/riscv/ultrarisc.yaml       |  27 +
> >  .../devicetree/bindings/vendor-prefixes.yaml       |   2 +
> >  MAINTAINERS                                        |  15 +
> >  arch/riscv/boot/dts/Makefile                       |   1 +
> >  arch/riscv/boot/dts/ultrarisc/Makefile             |   3 +
> >  .../dts/ultrarisc/dp1000-milkv-titan-pinctrl.dtsi  | 107 +++
> >  .../boot/dts/ultrarisc/dp1000-milkv-titan.dts      | 182 +++++
> >  .../dts/ultrarisc/dp1000-rongda-m0-pinctrl.dtsi    |  85 ++
> >  arch/riscv/boot/dts/ultrarisc/dp1000-rongda-m0.dts | 111 +++
> >  arch/riscv/boot/dts/ultrarisc/dp1000.dtsi          | 851 +++++++++++++++++++++
> >  arch/riscv/configs/defconfig                       |   1 +
> >  drivers/pinctrl/Kconfig                            |   1 +
> >  drivers/pinctrl/Makefile                           |   1 +
> >  drivers/pinctrl/ultrarisc/Kconfig                  |  23 +
> >  drivers/pinctrl/ultrarisc/Makefile                 |   4 +
> >  drivers/pinctrl/ultrarisc/pinctrl-dp1000.c         | 112 +++
> >  drivers/pinctrl/ultrarisc/pinctrl-ultrarisc.c      | 746 ++++++++++++++++++
> >  drivers/pinctrl/ultrarisc/pinctrl-ultrarisc.h      |  71 ++
> >  .../dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h |  65 ++
> >  21 files changed, 2577 insertions(+)
> > ---
> > base-commit: 50897c955902c93ae71c38698abb910525ebdc89
> > change-id: 20260316-ultrarisc-pinctrl-efa6e24c4803
> > 
> > Best regards,
> > --  
> > Jia Wang <wangjia@xxxxxxxxxxxxx>
> >