On 13.01.25 16:58, Frank Li wrote: > On Mon, Jan 13, 2025 at 02:42:51PM +0100, Ahmad Fatoum wrote: >> The imx8m-clock.yaml binding covers the clock controller inside all >> of the i.MX8M Q/M/N/P SoCs. All of them have in common that they >> support two operating modes: nominal and overdrive mode. >> >> While the overdrive mode allows for higher frequencies for many IPs, >> the nominal mode needs a lower SoC voltage, thereby reducing >> heat generation and power usage. >> >> As increasing clock rates beyond the maximum permitted by the supplied >> SoC voltage can lead to difficult to debug issues, device tree consumers >> would benefit from knowing what mode is active to enforce the clock rate >> limits that come with it. >> >> To facilitate this, extend the clock controller bindings with an >> optional fsl,operating-mode property. This intentionally allows the >> absence of the property, 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. >> >> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> >> --- >> Documentation/devicetree/bindings/clock/imx8m-clock.yaml | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> index c643d4a814786a1fc7e559140fe58911990f71bb..b03672255cae9462013a8a4e7a2adaff440f1420 100644 >> --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> @@ -43,6 +43,16 @@ properties: >> ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h >> for the full list of i.MX8M clock IDs. >> >> + fsl,operating-mode: >> + $ref: /schemas/types.yaml#/definitions/string >> + description: >> + The operating mode of the SoC. This affects the maximum clock rates that >> + can safely be configured by the clock controller. >> + oneOf: >> + - enum: >> + - nominal >> + - overdrive > > I remember > > fsl,operating-mode: > enum: [nominal, overdrive] > > should work without oneOf Yes, you're right. This is a left-over from the example I copy-pasted from. Thanks, will fix for v4. Feel free to leave some Reviewed-by on the other patches though in the mean-time. :-) Cheers, Ahmad > > Frank > > >> + >> required: >> - compatible >> - reg >> @@ -109,6 +119,7 @@ examples: >> <&clk_ext3>, <&clk_ext4>; >> clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2", >> "clk_ext3", "clk_ext4"; >> + fsl,operating-mode = "nominal"; >> }; >> >> - | >> >> -- >> 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 |
