[PATCH v1] arm: global_data: add scmi pointer

[Peng Fan]

Hi Simon,

> Subject: Re: [PATCH v1] arm: global_data: add scmi pointer
> 
> Hi Peng,
> 
> On Mon, 7 Oct 2024 at 20:59, Peng Fan <peng.fan at nxp.com> wrote:
> >
> > > Subject: Re: [PATCH v1] arm: global_data: add scmi pointer
> > >
> > > On Sun, Oct 06, 2024 at 05:52:28PM +0800,
> alice.guo at oss.nxp.com
> > > wrote:
> > > > From: Peng Fan <peng.fan at nxp.com>
> > > >
> > > > Add scmi device and channel pointer for i.MX9.
> > > >
> > > > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> > > > Signed-off-by: Alice Guo <alice.guo at nxp.com>
> > > > Reviewed-by: Ye Li <ye.li at nxp.com>
> > > > ---
> > > >  arch/arm/include/asm/global_data.h | 3 +++
> > > >  1 file changed, 3 insertions(+)
> > > >
> > > > diff --git a/arch/arm/include/asm/global_data.h
> > > > b/arch/arm/include/asm/global_data.h
> > > > index 45401d5e3c..d04359f167 100644
> > > > --- a/arch/arm/include/asm/global_data.h
> > > > +++ b/arch/arm/include/asm/global_data.h
> > > > @@ -108,6 +108,9 @@ struct arch_global_data {  #ifdef
> > > CONFIG_SMBIOS
> > > >     ulong smbios_start;             /* Start address of SMBIOS
> > > table */
> > > >  #endif
> > > > +#if defined(CONFIG_SCMI_FIRMWARE) &&
> defined(CONFIG_IMX9)
> > > > +   struct udevice *scmi_dev;
> > > > +#endif
> > > >  };
> > > >
> > > >  #include <asm-generic/global_data.h>
> > >
> > > But why is this only needed for i.MX9 families and not other users?
> >
> > i.MX95 has some code that communicates with SCMI platform, but
> no scmi
> > driver for those code, saying rom pass info. So we need a global
> > scmi_dev.
> 
> Would it be OK to find the device using
> uclass_first_device(UCLASS_SMCI) ?
> 
> i.e. can we do without a pointer in global_data ?

It should be doable to drop the pointer. We will give a look to
use the other approach.

Thanks,
Peng.

> 
> If we do need it, I think it is better to have the condition just be
> SCMI_FIRMWARE (and live with the extra 8 bytes in global_data). We
> really should not have SoC-specific options in global_data, or even
> drivers for that matter.
> 
> Regards,
> Simon
> e