Quoting Rafael J. Wysocki (2018-06-13 01:27:39) > On Wed, Jun 13, 2018 at 10:13 AM, Andy Shevchenko > <andy.shevchenko@xxxxxxxxx> wrote: > > +Cc: Rafael, ACPI ML > > > > On Wed, Jun 13, 2018 at 7:14 AM, Srinath Mannam > > <srinath.mannam@xxxxxxxxxxxx> wrote: > >> Hi Michael, Stephen, > >> > >> We are adding ACPI support in our Linux based platform. > >> At present our clock hierarchy using common clock framework through DTS. > >> Now we required ACPI support in common clock framework to upgrade our platform. > >> > >> For example, clk_get API called in many drivers to get clock device is > >> tightly coupled with DT framework. > >> > >> Please let us know, if anybody in Open Source community have plans to > >> add ACPI support for common clock framework. > > There are no plans for doing that AFAICS. > > Moreover, it generally would not be consistent with ACPI power > management defined by the specification. This matches my understanding. > > >> If not please suggest us alternative method to use common clock > >> framework in ACPI use case. > > The problem with using the clock framework on systems with ACPI is > that, in general, the clock manipulation is expected to be carried out > by ACPI power management and therefore it is "owned" by AML. > Currently, there are no defined methods for synchronizing the AML's > use of clocks for power management with what the OS may do with them > directly. > > In theory, that can be worked around to some extent by representing > clocks as power resources in ASL (even though the provider information > would be missing then) and manipulating those power resources directly > from the OS. I'm not aware of anyone doing that successfully, > however. > > For simple power management it should be sufficient to let drivers > rely on the ACPI PM domain which should happen automatically in the > majority of cases anyway. > Is this for clk_enable/disable? What about clk_set_rate() or clk_set_phase()? Is ACPI's AML taking care of that? -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
