On 02/04/2022 14:20, Johan Jonker wrote: > > > On 4/2/22 14:16, Krzysztof Kozlowski wrote: >> On 02/04/2022 13:45, Johan Jonker wrote: >>> >>> >>> On 4/2/22 13:41, Krzysztof Kozlowski wrote: >>>> On 01/04/2022 09:55, Heiko Stübner wrote: >>>>> 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. >>>> >>>> Are you sure that xin32k (RTC) clock should be input to the clock >>>> controller? I would expect it is the input to the SoC RTC block, so >>>> there is no circular dependency. >>> >>> clk-rk3188.c: >>> >>> PNAME(mux_pll_p) = { "xin24m", "xin32k" }; >> >> Thanks, but that's not the answer whether it is an input to the clock >> controller. It's the answer how the driver implements this. :) > > PX2 == rk3066 > > Rockchip PX2 TRM V1.0.pdf > > page 30 > > Chip Clock Architecture Diagram 1 I found it, thanks. That's the answer, so indeed this is an input. Answering partially to Heiko/Stephen, this could be still modeled in DTS as a fixed-frequency clock going as input to the clock-controller. The trouble with that approach is that it would actually duplicate the definition (another one coming from PMIC). Best regards, Krzysztof
