[RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[Benoit Cousson]

Hi Magnus,

This not-yet-ready-to-merge series is adding CPUFreq support to Lager board.

Due to the missing data for the OPP voltage values, a safe 1.0v value is
used for all OPPs.

At least this series can be used by Laurent to test the z-clock CCF node
and the KICK bit fix I've just sent.

Bottom-line, no real DVFS so far, but just DFS :-)

Please note that this series is safe even in the case of Cortex A7 boot
since the cpufreq-cpu0 driver is using the physical CPU@0 device node.
In the case of CA7 boot, the first cpu will be the CPU@100, and thus
the driver will fail at probe time due to the lack of CPU@0.

Regards,
Benoit 


Benoit Cousson (4):
  ARM: dts: r8a7790-lager: Add VDD MPU regulator for DVFS
  ARM: dts: r8a7790-lager: Add DVFS parameters into cpu0 node for
    r8a7790
  ARM: shmobile: lager-reference: Add cpufreq-cpu0 device for CPUFreq
    support
  ARM: shmobile: Make r8a77900 CPUFreq capable

 arch/arm/boot/dts/r8a7790-lager.dts            | 25 +++++++++++++++++++++++++
 arch/arm/boot/dts/r8a7790.dtsi                 | 11 +++++++++++
 arch/arm/mach-shmobile/Kconfig                 |  2 ++
 arch/arm/mach-shmobile/board-lager-reference.c |  3 +++
 4 files changed, 41 insertions(+)

-- 
1.8.3.2

Re: [RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[Laurent Pinchart]

Hi Benoit,

On Thursday 27 February 2014 00:09:46 Benoit Cousson wrote:
> Hi Magnus,
> 
> This not-yet-ready-to-merge series is adding CPUFreq support to Lager board.
> 
> Due to the missing data for the OPP voltage values, a safe 1.0v value is
> used for all OPPs.
> 
> At least this series can be used by Laurent to test the z-clock CCF node
> and the KICK bit fix I've just sent.
> 
> Bottom-line, no real DVFS so far, but just DFS :-)
> 
> Please note that this series is safe even in the case of Cortex A7 boot
> since the cpufreq-cpu0 driver is using the physical CPU@0 device node.
> In the case of CA7 boot, the first cpu will be the CPU@100, and thus
> the driver will fail at probe time due to the lack of CPU@0.

I'd like to test that on r8a7791, can I use the same parameters (voltages, 
frequencies and OPPs) ?

> Benoit Cousson (4):
>   ARM: dts: r8a7790-lager: Add VDD MPU regulator for DVFS
>   ARM: dts: r8a7790-lager: Add DVFS parameters into cpu0 node for
>     r8a7790
>   ARM: shmobile: lager-reference: Add cpufreq-cpu0 device for CPUFreq
>     support
>   ARM: shmobile: Make r8a77900 CPUFreq capable
> 
>  arch/arm/boot/dts/r8a7790-lager.dts            | 25 +++++++++++++++++++++++
>  arch/arm/boot/dts/r8a7790.dtsi                 | 11 +++++++++++
>  arch/arm/mach-shmobile/Kconfig                 |  2 ++
>  arch/arm/mach-shmobile/board-lager-reference.c |  3 +++
>  4 files changed, 41 insertions(+)

-- 
Regards,

Laurent Pinchart

Re: [RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[Benoit Cousson]

Salut Laurent,

On 28/02/2014 14:53, Laurent Pinchart wrote:
> Hi Benoit,
>
> On Thursday 27 February 2014 00:09:46 Benoit Cousson wrote:
>> Hi Magnus,
>>
>> This not-yet-ready-to-merge series is adding CPUFreq support to Lager board.
>>
>> Due to the missing data for the OPP voltage values, a safe 1.0v value is
>> used for all OPPs.
>>
>> At least this series can be used by Laurent to test the z-clock CCF node
>> and the KICK bit fix I've just sent.
>>
>> Bottom-line, no real DVFS so far, but just DFS :-)
>>
>> Please note that this series is safe even in the case of Cortex A7 boot
>> since the cpufreq-cpu0 driver is using the physical CPU@0 device node.
>> In the case of CA7 boot, the first cpu will be the CPU@100, and thus
>> the driver will fail at probe time due to the lack of CPU@0.
>
> I'd like to test that on r8a7791, can I use the same parameters (voltages,
> frequencies and OPPs) ?

For the frequency, it will be similar since the r8a7791 seems to run at 
1.3 GHz as well.

For the voltage, it should be similar, but I do not have any information 
and I'm not sure that the regulator used on the Koelsh board is the same 
(da9210).
It might be safer to remove the phandle to the regulator.
I hope the cpufreq-cpu0 driver probe will not fail becasue of that.

Regards,
Benoit

-- 
Benoît Cousson
BayLibre
Embedded Linux Technology Lab
www.baylibre.com

Re: [RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[Geert Uytterhoeven]

On Fri, Feb 28, 2014 at 3:15 PM, Benoit Cousson <bcousson@baylibre.com> wrote:
> For the voltage, it should be similar, but I do not have any information and
> I'm not sure that the regulator used on the Koelsh board is the same
> (da9210).

Koelsch also has a DA9210 regulator. At first sight, the wiring seems similar.
It's connected to i2c6 instead of i2c3, though.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [RFC 0/4] ARM: shmobile: Add CPUFreq support for r8a7790-lager platform

[Benoit Cousson]

On 28/02/2014 15:54, Geert Uytterhoeven wrote:
> On Fri, Feb 28, 2014 at 3:15 PM, Benoit Cousson <bcousson@baylibre.com> wrote:
>> For the voltage, it should be similar, but I do not have any information and
>> I'm not sure that the regulator used on the Koelsh board is the same
>> (da9210).
>
> Koelsch also has a DA9210 regulator. At first sight, the wiring seems similar.
> It's connected to i2c6 instead of i2c3, though.

OK, that's a good news. Thanks for checking.


Laurent,

In order to check the voltage, just enable the DA9210 driver but do not 
enable cpufreq.

Then just check the regulator voltage. It was 1.08v by default on the Lager.

Regards,
Benoit

>
> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sh" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>


-- 
Benoît Cousson
BayLibre
Embedded Linux Technology Lab
www.baylibre.com