[PATCH v4 4/5] rockchip: Separate the reset cause from display cpuinfo

[Jagan Teki]

Hi Kever,

On Sun, Jun 28, 2020 at 8:17 AM Kever Yang <kever.yang at rock-chips.com> wrote:
>
> HI Jagan,
>
> On 2020/6/18 下午11:39, Jagan Teki wrote:
> > reset cause is a generic functionality based on the soc
> > cru registers in rockchip. This can be used for printing
> > the cause of reset in cpuinfo or some other place where
> > reset cause is needed.
> >
> > Other than cpuinfo, reset cause can also be using during
> > bootcount for checking the specific reset cause and glow
> > the led based on the reset cause.
> >
> > So, let's separate the reset cause code from cpuinfo, and
> > add a check to build it for rk3399, rk3288 since these two
> > soc are supporting reset cause as of now.
> >
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > Tested-by: Suniel Mahesh <sunil at amarulasolutions.com>
> > ---
> > Changes for v4:
> > - none
> >
> >   arch/arm/include/asm/arch-rockchip/cru.h |  2 ++
> >   arch/arm/mach-rockchip/Makefile          |  5 ++++-
> >   arch/arm/mach-rockchip/cpu-info.c        | 20 ++++++++++++--------
> >   3 files changed, 18 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/arm/include/asm/arch-rockchip/cru.h b/arch/arm/include/asm/arch-rockchip/cru.h
> > index 5eb17f9d55..317eb61049 100644
> > --- a/arch/arm/include/asm/arch-rockchip/cru.h
> > +++ b/arch/arm/include/asm/arch-rockchip/cru.h
> > @@ -31,4 +31,6 @@ enum {
> >
> >   #define MHz         1000000
> >
> > +char *get_reset_cause(void);
>
> Since you add a environment, you should use that instead of export
> get_reset_cause().

Yes we can read reset_reason env in SPL but there is a fundamental
issue with this, say the previous reset cause is RST so the env set to
RST. For next power-on reset the reset_reason still shows RST since it
was updated previously but the actual cause of the reset is POR.

Jagan.