Messages in this thread | | | Date | Wed, 7 Feb 2024 13:03:37 +0530 | Subject | Re: [PATCH v2] clk: keystone: sci-clk: Adding support for non contiguous clocks | From | "Kumar, Udit" <> |
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On 2/7/2024 12:53 PM, CHANDRU DHAVAMANI wrote: > > On 07/02/24 11:03, Kumar, Udit wrote: >> >> On 2/6/2024 9:24 PM, Kamlesh Gurudasani wrote: >>> "Kumar, Udit" <u-kumar1@ti.com> writes: >>> >>>>>>>> get_freq is a bit expensive as it has to walk the clock tree to >>>>>>>> find >>>>>>>> the clock frequency (at least the first time?). just wondering if >>>>>>>> there is lighter alternative here? >>>>>>>> >>>>>>> How about get_clock? Doesn't read the registers at least. >>>>>> Said API needs, some flags to be passed, >>>>>> >>>>>> Can those flag be set to zero, Chandru ? >>>>> >>>>> get_clock doesn't require any flags to be passed. >>>> >>>> May be firmware does not need it but I was referring to >>>> >>>> https://elixir.bootlin.com/linux/latest/source/drivers/clk/keystone/sci-clk.c#L78 >>>> >>> Just took a look, >>> >>> I now understand the reason for confusion, >>> >>> #define TI_SCI_MSG_SET_CLOCK_STATE 0x0100 >>> #define TI_SCI_MSG_GET_CLOCK_STATE 0x0101 >>> >>> cops->get_clock = ti_sci_cmd_get_clock; --> refers to >>> TI_SCI_MSG_SET_CLOCK_STATE >>> That's why we are passing the flag from linux for get_clock >>> >>> Linux is using terminology of get/put. >>> >>> As Chandru pointed, we don't have to pass flags, cause he is refering >>> to TI_SCI_MSG_GET_CLOCK_STATE >>> >>> Below functions passes TI_SCI_MSG_GET_CLOCK_STATE to DM, which is what >>> we actually want. >>> cops->is_auto = ti_sci_cmd_clk_is_auto; >>> cops->is_on = ti_sci_cmd_clk_is_on; >>> cops->is_off = ti_sci_cmd_clk_is_off; >> >> >> I think calling ti_sci_cmd_clk_is_auto should be good . other >> functions needs current state and requested state. >> >> Chandru ? >> > > ti_sci_cmd_clk_is_auto is internal function to linux. > For TI_SCI_MSG_GET_CLOCK_STATE, linux only needs to pass pointers to > the variables where result will be stored.
Yes this internal function calls TI_SCI_MSG_GET_CLOCK_STATE
> > >>> >>> Which should be safe to call, Chandru can confirm. >>> >>> Regards, >>> Kamlesh >>>> >>>> >>>>> >>>>>> >>>>>>> Regards, >>>>>>> Kamlesh
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