rk_tsadc breaks (my) Rock64

[Emmanuel Vadot]

On Mon, 2 Dec 2019 22:13:22 +1100
Peter Jeremy <peter at rulingia.com> wrote:

> On 2019-Dec-01 22:07:16 +1100, Peter Jeremy <peter at rulingia.com> wrote:
> >r355173 added code to read the Rockchip temperature sensors.  Unfortunately,
> >this breaks on my Rock64.  I've tried to understand what's going wrong but
> >haven't managed to make much headway.  It looks like there some configuration
> >missing from syscon that tsadc needs but I'm not sure what (and I don't really
> >understand what syscon is doing).  I'd appreciate any insights.
> 
> I've added a pile of printf's and done some more digging and have made some
> progress.
> 
> Firstly, I've found that the syscon at ff100000 FDT entry attaches as two
> distinct devices:
> rk_grf0: <RockChip General Register Files> mem 0xff100000-0xff100fff on ofwbus0
>   (via compatible = "rockchip,rk3328-grf")
> simple_mfd0: <Simple MFD (Multi-Functions Device)> mem 0xff450000-0xff45ffff on ofwbus0
>   (via compatible = "simple-mfd")

 ??? those aren't the same devices.

> Based on the traceback going via simple_mfd_syscon_write_4(), I had assumed
> that tsadc_attach() was using the latter device but when I added code to
> print structure addresses, I discovered it was the former.
> 
> This makes the problem clearer: rk_grf0 requests and is allocated 4KiB
> memory ("reg = <0x0 0xff100000 0x0 0x1000>;" in the FDT and
> "mem 0xff100000-0xff100fff" in the device attach message above) but the
> tsadc_init() code is doing:
>                         SYSCON_WRITE_4(sc->grf, GRF_TSADC_TESTBIT_L,
>                             GRF_TSADC_VCM_EN_L);
> with
> #define GRF_TSADC_TESTBIT_L                     0x0e648
> and that offset is well outside the 4KiB allocated to the device.
> (On the positive side, a panic makes the problem a lot clearer than
> writing to a random device location would have been).
> 
> Ganbold's followup shows that the RK3399 allocates 64KiB to the syscon
> device so the equivalent write is valid on a RK3399.
> 
> I suspect the problem is that the following defines are only valid for
> the RK3399 since I can't find any matches to either the names or offsets
> in the following:
> #define GRF_SARADC_TESTBIT                      0x0e644
> #define GRF_TSADC_TESTBIT_L                     0x0e648
> #define GRF_TSADC_TESTBIT_H                     0x0e64c
> 
> Unfortunately, that also means I currently have no idea what the RK3328
> equivalents to those offsets are.
> 
> -- 
> Peter Jeremy

root at rock64:~ # uname -a
FreeBSD rock64.home.blih.net 13.0-CURRENT FreeBSD 13.0-CURRENT #13 r355188:355190M: Thu Nov 28 21:43:00 CET 2019     manu at skull.home.blih.net:/usr/home/manu/Work/freebsd/obj/usr/home/manu/Work/freebsd/freebsd-svn/base/head/arm64.aarch64/sys/GENERIC  arm64
root at rock64:~ # sysctl hw.temperature
hw.temperature.CPU: 50.7C

 Everything is working for me after I've added the clocks, so I don't
know what's happening for you. But after looking again at the docs it
seems that rk3328 is a mix between v2 and v3 so the GRF write are wrong.
 I'll have a look today or tomorow and fix this.

-- 
Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>