Re: [PATCH v4 7/8] soc: starfive: Add socinfo driver for JHB100 SoC

Hi,Conor

Thanks for the review.

> On Thu, Aug 13, 2026 at 08:10:12AM +0000, Changhuang Liang wrote:
> > Hi ,Conor
> >
> > Thanks for the review.
> >
> > > On Wed, Aug 12, 2026 at 10:37:16AM +0000, Changhuang Liang wrote:
> > > > Hi, Conor
> > > >
> > > > Thanks for the review.
> > > >
> > > > > On Tue, Aug 11, 2026 at 05:36:19AM +0000, Changhuang Liang wrote:
> > > > >
> > > > > > > On Sat, Aug 08, 2026 at 06:50:53PM -0700, Changhuang Liang
> wrote:
> > > > >
> > > > > > > > +static int __init starfive_socinfo_init(void) {
> > > > > > > > +	struct soc_device_attribute *attrs;
> > > > > > > > +	struct soc_device *soc_dev;
> > > > > > > > +	const char *machine = NULL;
> > > > > > > > +	struct device_node *np;
> > > > > > > > +	struct regmap *regmap;
> > > > > > > > +	char rev_char;
> > > > > > > > +	u32 rev_id;
> > > > > > > > +	int ret;
> > > > > > > > +
> > > > > > > > +	np = of_find_compatible_node(NULL, NULL,
> > > > > > > > +"starfive,jhb100-sys0-syscon");
> > > > > > >
> > > > > > > Remind me again why this is not just probed as an mfd cell
> > > > > > > from the syscon driver?
> > > > > > >
> > > > > > > (Hint: please put this info in the commit message).
> > > > > >
> > > > > > The discussion result with Krzysztof at that time is recorded here:
> > > > > > https://lore.kernel.org/all/20260405-strong-watchful-marmot-fd
> > > > > > fad6
> > > > > > @quo
> > > > > > ll/
> > > > > >
> > > > > > One register should not be treated as a separate device node.
> > > > >
> > > > > That's a different question. In the case of an mfd cell probed
> > > > > from the syscon driver there would be no devicetree
> > > > > modifications required compared to what you have now. e.g.
> > > > > sg2044-topsys.c
> > > >
> > > > This seems feasible, and I can introduce this modification in the
> > > > next
> > > version.
> > >
> > >
> > > In fact, you don't even need the mfd cell, because your driver is
> > > going to be in drivers/soc/starfive anyway? You can just bind
> > > directly to the
> > > sys0 syscon I think.
> >
> > I suddenly realized that I missed one issue:
> > starfive,jhb100-sys0-syscon is already bound to the PLL driver by default, I
> can't use it to bind another device anymore.
> >
> > which is why I used
> >
> > np = of_find_compatible_node(NULL, NULL,
> > "starfive,jhb100-sys0-syscon");
> >
> > in jhb100-socinfo.c.
> >
> > So it seems the MFD cell approach isn't really feasible either?
> 
> You could, in that case, probe the clock driver using the mfd_cell like
> sg2044-topsys. What else other than the pll controls and the soc info register
> is in this register region?

We don't have any other drivers right now in this register region.

So does that mean I can revise it to the format below:

static const struct mfd_cell jhb100_sys0_subdev[] = {
	{
		.name = "jhb100-sys0-pll",
	},
	{
		.name = "jhb100-socinfo",
	},
};

static const struct mfd_cell jhb100_per0_subdev[] = {
	{
		.name = "jhb100-per0-pll",
	},
};

static const struct mfd_cell jhb100_per1_subdev[] = {
	{
		.name = "jhb100-per1-pll",
	},
};

static const struct mfd_cell jhb100_ pcierp _subdev[] = {
	{
		.name = "jhb100-pcierp-reset",
	},
};

Best Regards,
Changhuang


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