On Tue, Aug 16, 2022 at 07:13:27AM +0000, Peng Fan wrote: > Hi Sascha, > > > Subject: Re: [PATCH 1/2] dt-bindings: clock: imx8m: introduce fsl,protected- > > clocks property > > > > Hi Peng, > > > > On Mon, Aug 15, 2022 at 11:36:31AM +0800, Peng Fan (OSS) wrote: > > > From: Peng Fan <peng.fan@xxxxxxx> > > > > > > i.MX8M Linux run on top of Jailhouse hypervisor, the root cell Linux > > > should not disable clocks used by inmate. This would also benifit AMP > > > to avoid Linux disable clocks used by Cortex-M4/M7. > > > > > > So introduce fsl,protected-clocks for above case. > > > > > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> > > > --- > > > Documentation/devicetree/bindings/clock/imx8m-clock.yaml | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > > > b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > > > index 458c7645ee68..0ec490ff9a09 100644 > > > --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > > > +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > > > @@ -39,6 +39,10 @@ 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,protected-clocks: > > > + description: List of the Protected clock. > > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > > > There already is a generic protected-clocks property described in > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu > > b.com%2Fdevicetree-org%2Fdt- > > schema%2Fblob%2F0d1b78cd0c3d9a3d523ced17d7da64b03f6c18ea%2Fdtsc > > hema%2Fschemas%2Fclock%2Fclock.yaml%23L131&data=05%7C01%7 > > Cpeng.fan%40nxp.com%7C5dbc72639c9147765af208da7ec63315%7C686ea > > 1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637961686968811809%7CUn > > known%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI > > 6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=D%2BfJA5h > > wblaX8VH%2BdQoN0pEFmCipfZHHf0ZVo07B4kg%3D&reserved=0 > > We probably shouldn't add a property with the same name but different > > meaning. > > > > Thanks for sharing the info. I should check the common bindings before > cook this patchset. > > > I am not sure if we want to go the route of a fsl specific property, it looks > > like other SoCs could have similar problems and it might be worth solving > > this problem with a broader view. > > > > I see qcom just drop the clock entries before registering the clocks. But to > i.MX8M, it is not feasible to drop those clocks, unless check the > protected-clocks property before registering every clock. This is odd. > > So here I just wanna let i.MX8M clk driver prepare enable the clocks listed > in protected-clocks property to avoid linux disable those clocks. > > Anyway, please add a description to the binding what this property actually > > does. > I will switch to use the common bindings. There were cases when a property first started with a "soc," prefix and later when people realized that it could be useful for other drivers/SoCs as well, the prefix was removed. With that in mind I would expect that a "fsl,protected-clocks" property behaves the same as a "protected-clocks" property without the prefix. If it doesn't please pick a different name. I didn't want to suggest to just drop the "fsl," prefix and to use the generic property name when the properties have a different meaning. Sascha -- 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 |
