On Sun 17 Mar 2024 at 18:52, Jan Dakinevich <jan.dakinevich@xxxxxxxxxxxxxxxxx> wrote: > On 3/15/24 13:22, Jerome Brunet wrote: >> >> On Fri 15 Mar 2024 at 11:00, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: >> >>> On 15/03/2024 00:21, Jan Dakinevich wrote: >>>> This option allow to redefine the rate of DSP system clock. >>> >>> And why is it suitable for bindings? Describe the hardware, not what you >>> want to do in the driver. >>> >>>> >>>> Signed-off-by: Jan Dakinevich <jan.dakinevich@xxxxxxxxxxxxxxxxx> >>>> --- >>>> Documentation/devicetree/bindings/sound/amlogic,axg-pdm.yaml | 4 ++++ >>>> 1 file changed, 4 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/sound/amlogic,axg-pdm.yaml b/Documentation/devicetree/bindings/sound/amlogic,axg-pdm.yaml >>>> index df21dd72fc65..d2f23a59a6b6 100644 >>>> --- a/Documentation/devicetree/bindings/sound/amlogic,axg-pdm.yaml >>>> +++ b/Documentation/devicetree/bindings/sound/amlogic,axg-pdm.yaml >>>> @@ -40,6 +40,10 @@ properties: >>>> resets: >>>> maxItems: 1 >>>> >>>> + sysrate: >>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>> + description: redefine rate of DSP system clock >>> >>> No vendor prefix, so is it a generic property? Also, missing unit >>> suffix, but more importantly I don't understand why this is a property >>> of hardware. >> >> +1. >> >> The appropriate way to set rate of the clock before the driver take over >> is 'assigned-rate', if you need to customize this for different >> platform. >> > > It would be great, but it doesn't work. Below, is what I want to see: > > assigned-clocks = > <&clkc_audio AUD2_CLKID_PDM_SYSCLK_SEL>, > <&clkc_audio AUD2_CLKID_PDM_SYSCLK_DIV>; > assigned-clock-parents = > <&clkc_pll CLKID_FCLK_DIV3>, > <0>; > assigned-clock-rates = > <0>, > <256000000>; > > But regardles of this declaration, PDM's driver unconditionally sets > sysclk'rate to 250MHz and throws away everything that was configured > before, reparents audio2_pdm_sysclk_mux to hifi_pll and changes > hifi_pll's rate. > > This value 250MHz is declared here: > > static const struct axg_pdm_cfg axg_pdm_config = { > .filters = &axg_default_filters, > .sys_rate = 250000000, > }; > > The property 'sysrate' is intended to redefine hardcoded 'sys_rate' > value in 'axg_pdm_config'. What is stopping you from removing that from the driver and adding assigned-rate to 250M is the existing platform ? > >> Then you don't have to deal with it in the device driver. >> >>> >>> Best regards, >>> Krzysztof >> >> -- Jerome