Quoting Heiko Stübner (2022-04-01 00:55:55) > Hi Stephen, > > Am Freitag, 1. April 2022, 00:51:32 CEST schrieb Stephen Boyd: > > Quoting Johan Jonker (2022-03-29 04:13:22) > > > diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.yaml b/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.yaml > > > new file mode 100644 > > > index 000000000..ddd7e46af > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.yaml > > > @@ -0,0 +1,78 @@ > > > +# SPDX-License-Identifier: GPL-2.0 > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/clock/rockchip,rk3188-cru.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Rockchip RK3188/RK3066 Clock and Reset Unit (CRU) > > > + > > > +maintainers: > > > + - Elaine Zhang <zhangqing@xxxxxxxxxxxxxx> > > > + - Heiko Stuebner <heiko@xxxxxxxxx> > > > + > > > +description: | > > > + The RK3188/RK3066 clock controller generates and supplies clocks to various > > > + controllers within the SoC and also implements a reset controller for SoC > > > + peripherals. > > > + Each clock is assigned an identifier and client nodes can use this identifier > > > + to specify the clock which they consume. All available clocks are defined as > > > + preprocessor macros in the dt-bindings/clock/rk3188-cru.h and > > > + dt-bindings/clock/rk3066-cru.h headers and can be used in device tree sources. > > > + Similar macros exist for the reset sources in these files. > > > + There are several clocks that are generated outside the SoC. It is expected > > > + that they are defined using standard clock bindings with following > > > + clock-output-names: > > > + - "xin24m" - crystal input - required > > > + - "xin32k" - RTC clock - optional > > > + - "xin27m" - 27mhz crystal input on RK3066 - optional > > > + - "ext_hsadc" - external HSADC clock - optional > > > + - "ext_cif0" - external camera clock - optional > > > + - "ext_rmii" - external RMII clock - optional > > > + - "ext_jtag" - external JTAG clock - optional > > > > I'd expect all these clks here to be inputs to this node. > > The optional clocks are all part of a circular dependency. > > So for example xin32k normally is generated by the pmic and fed > back into the system, so to get xin32k, we need the pmic to probe, > which needs i2c, which in turn already needs the clock controller. > > Or optional clocks may not be available at all. > > So for the past years we already relied on the clock-system's > self adaptation if a clock becomes available at some point > during later boot and hence do not have those in a clocks-property. > Are you saying that we can't have these clks in the clocks property because there's a circular driver probe dependency? I don't see how that matters for the dt binding. What is broken if they're put in the binding and specified in the node?
