: imx: mx6: use OTP for temperature grade and freq grade

Quoted 58 lines · Tim Harvey

Quoted 20 lines · Stefan Roese

Hi Tim,

Quoted 7 lines · Tim Harvey

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.

Quoted 8 lines

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.

Quoted 7 lines

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).

Quoted 1 line

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 ;)