On Fri, Feb 4, 2022 at 6:00 PM Sean Anderson <sean.anderson@xxxxxxxx> wrote: > On 2/4/22 7:54 AM, Andy Shevchenko wrote: ... > > On Thursday, January 27, 2022, Sean Anderson <sean.anderson@xxxxxxxx <mailto:sean.anderson@xxxxxxxx>> wrote: > > Is it function or interface clock? > > > > We have standard property for the functional clock rate, I.e. “clock-frequency” (in Hz), can it be used here? > > I believe this is a "functional" clock. It it is a reference for the USB > signals. I'm not sure exactly what the purpose of this clock is, since I > do not have access to the databook for this IP. I considered using > "clock-frequency", but I am concerned about ambiguity because there is a > second "suspend" clock which is also a "functional" clock. The latter > clock appears to be used when the PHY is shut down (and not necessarily > corresponding to Linux's notion of a suspended device). If it is > necessary in the future to configure that clock on ACPI platforms (e.g. > to set GCTL.PWRDNSCALE) I think it is clear what the property name would > be (snps,susp-clock-frequency-hz). In order to have more or less unified APIs in the future I would suggest using 'clock-frequency' for the "main" functional clock. For example, 8250_dw uses it for the baud rate generator, while it also utilizes auxiliary clock(s) on some platforms. -- With Best Regards, Andy Shevchenko
