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

[Christian Gmeiner]

2015-05-07 17:55 GMT+02:00 Tim Harvey <tharvey at gateworks.com>:
> 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 ;)
>

Acked-by: Christian Gmeiner <christian.gmeiner at gmail.com>

greets
--
Christian Gmeiner, MSc

https://soundcloud.com/christian-gmeiner