Re: [PATCH] soc: ti: k3-socinfo: Do not use syscon helper to build regmap

[Nishanth Menon]

On 12:17-20250123, Andrew Davis wrote:
> The syscon helper device_node_to_regmap() is used to fetch a regmap
> registered to a device node. It also currently creates this regmap
> if the node did not already have a regmap associated with it. This
> should only be used on "syscon" nodes. This driver is not such a
> device and instead uses device_node_to_regmap() on its own node as
> a hacky way to create a regmap for itself.
> 
> This will not work going forward and so we should create our regmap
> the normal way by defining our regmap_config, fetching our memory
> resource, then using the normal regmap_init_mmio() function.
> 
> Signed-off-by: Andrew Davis <afd@xxxxxx>
> ---

This is part of the fixes TI K3 platforms boot issues reported in
https://lore.kernel.org/all/b2413460-ec8b-4c77-99b8-4c32b262439a@xxxxxx/
on the latest linus master v6.13-5001-gd0d106a2bd21 + linux
next-20250123

Total set of patches tested with:
https://lore.kernel.org/all/20250119182121.3956546-1-vaishnav.a@xxxxxx/
https://lore.kernel.org/r/20250123181726.597144-1-afd@xxxxxx
https://lore.kernel.org/r/20250123181913.597304-1-afd@xxxxxx
https://lore.kernel.org/r/20250123182059.597491-1-afd@xxxxxx
https://lore.kernel.org/r/20250123182234.597665-1-afd@xxxxxx

I will try and get this in at the earliest possible window. Thanks for
providing a fix.

Cc Rob and Lee

>  drivers/soc/ti/k3-socinfo.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
> index 4fb0f0a248288..704039eb3c078 100644
> --- a/drivers/soc/ti/k3-socinfo.c
> +++ b/drivers/soc/ti/k3-socinfo.c
> @@ -105,6 +105,12 @@ k3_chipinfo_variant_to_sr(unsigned int partno, unsigned int variant,
>  	return -ENODEV;
>  }
>  
> +static const struct regmap_config k3_chipinfo_regmap_cfg = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +};
> +
>  static int k3_chipinfo_probe(struct platform_device *pdev)
>  {
>  	struct device_node *node = pdev->dev.of_node;
> @@ -112,13 +118,18 @@ static int k3_chipinfo_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct soc_device *soc_dev;
>  	struct regmap *regmap;
> +	void __iomem *base;
>  	u32 partno_id;
>  	u32 variant;
>  	u32 jtag_id;
>  	u32 mfg;
>  	int ret;
>  
> -	regmap = device_node_to_regmap(node);
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	regmap = regmap_init_mmio(dev, base, &k3_chipinfo_regmap_cfg);
>  	if (IS_ERR(regmap))
>  		return PTR_ERR(regmap);
>  
> -- 
> 2.39.2
> 

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D