On Fri, Jul 22, 2022 at 6:06 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.
When we refer to functions we put it like func().
> 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.
...
> +#include <linux/err.h>
You also missed errno.h
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
...
> +static inline struct regmap *
> +ocelot_regmap_from_resource_optional(struct platform_device *pdev,
> + unsigned int index,
> + const struct regmap_config *config)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + void __iomem *regs;
> +
> + /*
> + * Don't use get_and_ioremap_resource here, since that will invoke
_get_and_ioremap_resource()
> + * prints of "invalid resource" which simply add confusion
> + */
will simply add
Missed period.
> + res = platform_get_resource(pdev, IORESOURCE_MEM, index);
Where are the IORESOURCE_* defined? Haven't you missed a header?
> + if (res) {
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return ERR_CAST(regs);
> + return devm_regmap_init_mmio(dev, regs, config);
> + }
> +
> + /*
> + * Fall back to using REG and getting the resource from the parent
> + * device, which is possible in an MFD configuration
> + */
> + if (dev->parent) {
> + res = platform_get_resource(pdev, IORESOURCE_REG, index);
> + if (!res)
> + return NULL;
> +
> + return dev_get_regmap(dev->parent, res->name);
> + }
> +
> + return NULL;
> +}
--
With Best Regards,
Andy Shevchenko
