[U-Boot] [PATCH 0/4]: imx: mx6: use OTP for temperature grade and freq grade

[Tim Harvey]

On Tue, Apr 28, 2015 at 10:31 AM, Tim Harvey <tharvey at gateworks.com> wrote:
> On Tue, Apr 28, 2015 at 10:11 AM, Stefan Roese <sr at denx.de> wrote:
>> Hi Tim,
>>
>> On 28.04.2015 17:44, Tim Harvey wrote:
>>>
>>> The MX6 has OTP bits specifying the processor speed grade as well as
>>> temperature grade.
>>>
>>> This series adds functions to return this information as well as adds the
>>> details to the CPU info displayed.
>>>
>>> Additionally we use the temperature grade to replace the hard-coded limits
>>> in imx_thermal.c
>>>
>>> I expect some possible discussion/debate regarding the displaying of this
>>> info,
>>> but perhaps adding the functions to obtain the info and use it for
>>> imx_thermal
>>> is beyond debate. Please let me know.
>>
>>
>> Could you please send (or include in the commit text) an example, how these
>> infos are displayed now in the bootup log? Best in comparison to the "old"
>> log. To see the output change resulting from the patchset.
>>
>> Thanks,
>> Stefan
>>
>
> Stefan,
>
> Good point - as I am guessing there will be debate about the 'amount'
> of info displayed and am open to suggestions on how to word it and/or
> how to enable it. In future revs of the patchset I'll be more explicit
> in the commit logs, but for now with the series applied I get this:
>
> IMX6Q automotive (1GHz capable) powering up at 800MHz:
> - before:
> CPU:   Freescale i.MX6Q rev1.2 at 792 MHz
> - after Patch 1/4:
> CPU:   Freescale i.MX6Q rev1.2 996 MHz (at 792 MHz)
> - after Patch 3/4 (if CONFIG_IMX6_THERMAL defined)
> CPU:   Freescale i.MX6Q rev1.2 automotive (-40C to 125C) 996 MHz (at 792 MHz)
>
> IMX6S industrial (800MHz capable) powering up at 800MHz:
> - before:
> CPU:   Freescale i.MX6SOLO rev1.2 at 792 MHz
> - after Patch 1/4: (max speed == cur speed)
> CPU:   Freescale i.MX6SOLO rev1.2 792 MHz
> - after Patch 3/4 (if CONFIG_IMX6_THERMAL defined)
> CPU:   Freescale i.MX6SOLO rev1.2 industrial (-40C to 105C) 792 MHz
>
> When I submit the next version I will split out adding the functions
> to get speed-grade and temperature-grade from using those functions in
> cpu_printinfo() as well as some may not be happy with adding more info
> to cpu_printinfo() but may find value in setting the thermal limits of
> imx_thermal properly based on temp-grade (Patch 4/4).
>
> Tim

Stefano,

I've cc'd all the maintainers I could find of MX6 based boards for
comment on adding this text to the mx6 print_cpuinfo. I would like to
see some ack/review from them otherwise I would think silence is
considered a thumbs up ;)

Regards,

Tim