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

[Tim Harvey]

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