Re: [PATCH] arm: mecsbc: fixup /regulator-sd device tree node

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Apr 05, 2024 at 01:46:26PM +0200, Ahmad Fatoum wrote:
> Hello Sascha,
> 
> On 05.04.24 12:12, Sascha Hauer wrote:
> > The MECSBC prototype board has a bug which makes the 1.8V SD mode
> > unusable. Add a fixup which sets the regulator-min-microvolt property of
> > the SD regulator to 3.3V to prevent the Kernel from going into 1.8V.
> 
> Isn't that what the MMC no-1-8-v device tree property is for?

Although it's described in mmc-controller.yaml this is not a generic property.
Only SDHCI based controllers evaluate this property (which the affected
controller here isn't)

Sascha

> 
> Cheers,
> Ahmad
> 
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  arch/arm/boards/protonic-mecsbc/board.c | 21 +++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> > 
> > diff --git a/arch/arm/boards/protonic-mecsbc/board.c b/arch/arm/boards/protonic-mecsbc/board.c
> > index 3ba8fb8d1c..56f7ca393a 100644
> > --- a/arch/arm/boards/protonic-mecsbc/board.c
> > +++ b/arch/arm/boards/protonic-mecsbc/board.c
> > @@ -90,6 +90,24 @@ static void mecsbc_process_adc(struct device *dev)
> >  	pr_info("VIN = %d V\n", mecsbc_get_vin_mv() / 1000);
> >  }
> >  
> > +static int mecsbc_sd_of_fixup(struct device_node *root, void *context)
> > +{
> > +	struct device *dev = context;
> > +	struct device_node *np;
> > +
> > +	dev_info(dev, "Fixing up /regulator-sd\n");
> > +
> > +	np = of_find_node_by_path_from(root, "/regulator-sd");
> > +	if (!np) {
> > +		dev_err(dev, "Cannot find /regulator-sd node\n");
> > +		return 0;
> > +	}
> > +
> > +	of_property_write_u32(np, "regulator-min-microvolt", 3300000);
> > +
> > +	return 0;
> > +}
> > +
> >  static int mecsbc_of_fixup_hwrev(struct device *dev)
> >  {
> >  	const char *compat;
> > @@ -103,6 +121,9 @@ static int mecsbc_of_fixup_hwrev(struct device *dev)
> >  
> >  	free(buf);
> >  
> > +	if (mecsbc_data.hw_id == 0 && mecsbc_data.hw_rev == 0)
> > +		of_register_fixup(mecsbc_sd_of_fixup, dev);
> > +
> >  	return 0;
> >  }
> >  
> 
> -- 
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> 

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