Re: [PATCH v11 net-next 1/9] mfd: ocelot: add helper to get regmap from a resource

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Tue, Jun 28, 2022 at 10:17 AM Colin Foster
<colin.foster@xxxxxxxxxxxxxxxx> wrote:
>
> Several ocelot-related modules are designed for MMIO / regmaps. As such,
> they often use a combination of devm_platform_get_and_ioremap_resource and
> devm_regmap_init_mmio.
>
> Operating in an MFD might be different, in that it could be memory mapped,
> or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
> instead of IORESOURCE_MEM becomes necessary.
>
> When this happens, there's redundant logic that needs to be implemented in
> every driver. In order to avoid this redundancy, utilize a single function
> that, if the MFD scenario is enabled, will perform this fallback logic.

> +       regs = devm_platform_get_and_ioremap_resource(pdev, index, &res);
> +
> +       if (!res)
> +               return ERR_PTR(-ENOENT);

This needs a comment why the original error code from devm_ call above
is not good here.

> +       else if (IS_ERR(regs))
> +               return ERR_CAST(regs);
> +       else
> +               return devm_regmap_init_mmio(&pdev->dev, regs, config);
> +}

'else' is redundant in all cases above.

-- 
With Best Regards,
Andy Shevchenko