[PATCH] ARM: shmobile: r8a7793: Add thermal device to DT

[Geert Uytterhoeven]

Hi Simon,

On Mon, Nov 9, 2015 at 2:15 AM, Simon Horman <horms at verge.net.au> wrote:
> On Fri, Nov 06, 2015 at 11:00:17AM +0100, Geert Uytterhoeven wrote:
>> On Fri, Nov 6, 2015 at 10:17 AM, Simon Horman <horms at verge.net.au> wrote:
>> > On Fri, Nov 06, 2015 at 09:50:27AM +0100, Geert Uytterhoeven wrote:
>> >> On Fri, Nov 6, 2015 at 8:30 AM, Simon Horman <horms+renesas at verge.net.au> wrote:
>> >> > Instantiate the thermal sensor in the r8a7793 device tree.
>> >> >
>> >> > Based on very similar work for the r8a7790 by Magnus Damm.
>> >>
>> >> Given the similarity of R-Car M2-N and M2-W, I would have referred
>> >> to r8a7791 ;-)
>> >
>> > True. Though for thermal the datasheet indicates H2 is also quite similar.
>> >
>> > I also prepared a very similar patch to add thermal to the r8a7794 (E2).
>> > But the driver reports the sensor is broken - my inspection of the code
>> > leads me to believe its not able to get a proper reading from the sensor.
>> >
>> > I'm wondering if anyone knows about this issue. Perhaps its specific
>> > to my Alt board. Or a limitation of the E2?
>>
>> Using the same kernel image as on other boards? I.e. it's not an MSTP
>> clock issue?
>
> I am using the same kernel image.
> I wonder if it is an MSTP issue.
>
> Looking over the datasheet I see:
>
> For the r8a779[0-4] Thermal in MSTPSR5, RMSTPCR5.
> I.e. there is a bit for thermal in those registers for all R-Car Gen-2
> SoCs covered by the datasheet.
>
> But only on the r8a779[0-3] I see thermal in SRCR5, SRSTCLR5.
> I.e. there is no bit for thermal in those registers for the r8a7794
> which is different from the other R-Car Gen-2 SoCs covered by the datasheet.

Indeed, strange. Those are the reset registers, which we don't use yet.

Can you please check from U-Boot that the thermal module is not held in reset?
On r8a7791/koelsch I get:

=> md.l 0xe61500c4 1
e61500c4: 00000000    ....
=> md.l 0xe6150954 1
e6150954: 00000000    ....

I.e. no reset or reset clear bit is set.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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