On Sat, Sep 7, 2019 at 2:38 AM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
>
> Hi Adam,
>
> > Am 02.09.2019 um 23:10 schrieb Adam Ford <aford173@xxxxxxxxx>:
> >
> > On Mon, Sep 2, 2019 at 10:46 AM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
> >>
> >>
> >>
> >> But my tests show that decoding works now. So you already might give it a try.
> >
> > I am traveling all this week, but I have an omap3530, DM3730
> > (omap3630), and an AM3517 that I use for testing.
>
> now as the omap3430 and omap3630 opp-v2 tables are installed,
> we could add am35x7 as well.
>
> What needs to be done:
>
> 1. add OPP-v2 table to am3517.dtsi
>
> for example copy skeleton from omap36xx.dtsi
>
> and define reasonable clock speeds. I would think about
> 150 MHz, 300 MHz, 600MHz.
This might be more of a question for TI, but can we match the 3430
list of frequencies?
Something like:
125000 1200000
250000 1200000
500000 1200000
550000 1200000
600000 1200000
>
> Debatable is if we need a clock-latency definition.
>
> 2. change all voltages to 1.2V
>
> opp-microvolt = <1200000 1200000 1200000>;
>
> There is no point to specify 3 voltages <target min max> here since we
> will never need a min and a max value.
>
> opp-microvolt = <1200000>;
>
> should also be ok (AFAIK, parser handles single-value records).
>
> 3. AFAIK there is no speed binned eFuse...
>
> But the ti-cpufreq driver always wants to read some eFuse register.
>
> So please check if you can read 0x4800244C and 0x4830A204
> like on omap36xx and if they produce stable values (and not
> random noise).
For the AM3517,
0x4800244C = 0000 0cc0
0x4830A204 = 1b86 802f
The AM3517 shows these are valid addresses and I read them multiple
times and they yielded the same results even after power cycling.
>
> If yes, we simply assume that am3517 is similar enough to omap3630,
> ignore that there is no eFuse, but read the register anyways and
> then ignore the bit if it is 0 or 1.
>
> This means that all OPPs can get
>
> opp-supported-hw = <0xffffffff 0xffffffff>;
>
> There could also be a default handler if this property is missing,
> but I have not researched this.
>
Like this?
opp1-125000000 {
opp-hz = /bits/ 64 <125000000>;
opp-microvolt = <1200000>;
opp-supported-hw = <0xffffffff 0xffffffff>;
};
opp2-250000000 {
opp-hz = /bits/ 64 <250000000>;
opp-microvolt = <1200000>;
opp-supported-hw = <0xffffffff 0xffffffff>;
opp-suspend;
};
opp3-500000000 {
opp-hz = /bits/ 64 <500000000>;
opp-microvolt = <1200000>;
opp-supported-hw = <0xffffffff 0xffffffff>;
};
opp4-550000000 {
opp-hz = /bits/ 64 <550000000>;
opp-microvolt = <1200000>;
opp-supported-hw = <0xffffffff 0xffffffff>;
};
opp5-600000000 {
opp-hz = /bits/ 64 <600000000>;
opp-microvolt = <1200000>;
opp-supported-hw = <0xffffffff 0xffffffff>;
};
What does opp-suspend do? I noticed it in the 34xx.dtsi
> 4. add compatible to ti-cpufreq
> and share the register offsets, bit masks etc. with omap3630:
>
> { .compatible = "ti,am33xx", .data = &am3x_soc_data, },
> { .compatible = "ti,am3517", .data = &omap36xx_soc_data, },
> { .compatible = "ti,am43", .data = &am4x_soc_data, },
> { .compatible = "ti,dra7", .data = &dra7_soc_data },
> { .compatible = "ti,omap3430", .data = &omap34xx_soc_data, },
> { .compatible = "ti,omap3630", .data = &omap36xx_soc_data, },
>
> 5. configure for CONFIG_ARM_TI_CPUFREQ=y
>
> This should IMHO suffice.
If you're OK with what I am proposing, I'll run some tests and submit
a patch. I won't promise to fully understand what's happening. :-)
>
> Since I can't test anything I can't define working OPP points
> and therefore I can't provide patches myself. Hope you can make
> it work this way.
>
> BR,
> Nikolaus
