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. :) Best regards, Krzysztof
