Hello Frank, On 06.01.25 20:42, Frank Li wrote: > On Mon, Jan 06, 2025 at 08:25:38PM +0100, Ahmad Fatoum wrote: >> On 06.01.25 17:41, Frank Li wrote: >>> On Mon, Jan 06, 2025 at 03:21:42PM +0100, Ahmad Fatoum wrote: >>>> Allowing for absence of both properties is >>>> needed, because there is no default suitable for all boards: >>>> >>>> For i.MX8M Mini and Nano, the kernel SoC DTSIs has assigned-clock-rates >>>> that are all achievable in nominal mode. For i.MX8MP, there are some >>>> rates only validated for overdrive mode. >>>> >>>> But even for the i.MX8M Mini/Nano boards, we don't know what rates they >>>> may configure at runtime, so it has not been possible so far to infer from >>>> just the device tree what the mode is. >> >> [snip] >> >>>> + fsl,nominal-mode: >>>> + description: Set if SoC is operated in nominal mode >>>> + $ref: /schemas/types.yaml#/definitions/flag >>>> + >>>> + fsl,overdrive-mode: >>>> + description: Set if SoC is operated in overdrive mode >>>> + $ref: /schemas/types.yaml#/definitions/flag >>>> + >>> >>> why need two flags? suppose "not set fsl,overdrive-mode" is equal to >>> fsl,nominal-mode >> >> Conor had the same question on v1[1] and I have addressed this in the commit >> message of v2, see above. >> >> In short, there is unfortunately no universally applicable default. >> >> [1]: https://lore.kernel.org/all/4e2250b3-5170-4e88-aa0a-dd796b81e78b@xxxxxxxxxxxxxx/ >> > > But there are problem if use dts overlay because dts overlay can't support > delete property. > > If one dts file use "fsl,overdrive-mode", dts overlay file can't delete > this property. "mutually exclusive optional properties" was not preferred. > > mode = ["normal" | "overdrive"] I don't see myself setting this via overlay, but if you say it's useful, we can adjust the binding. I am not sure what's the preference is though, should we have fsl,operating-mode = "normal" / "overdrive" or fsl,operating-mode = <IMX_OPMODE_NORMAL> / <IMX_OPMODE_OVERDRIVE> Any idea? Conor? Cheers, Ahmad > > Frank > >> Thanks, >> Ahmad >> >> >>> >>> Frank >>> >>>> required: >>>> - compatible >>>> - reg >>>> @@ -95,6 +103,12 @@ allOf: >>>> - const: clk_ext2 >>>> - const: clk_ext3 >>>> - const: clk_ext4 >>>> + - if: >>>> + required: >>>> + - fsl,overdrive-mode >>>> + then: >>>> + properties: >>>> + fsl,nominal-mode: false >>>> >>>> additionalProperties: false >>>> >>>> >>>> -- >>>> 2.39.5 >>>> >>> >> >> >> -- >> Pengutronix e.K. | | >> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
