/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/* Copyright 2022 Innovative Advantage Inc. */

#ifndef _LINUX_MFD_OCELOT_H
#define _LINUX_MFD_OCELOT_H

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/types.h>

struct resource;

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
     * prints of "invalid resource" which will simply add confusion.
     */
    res = platform_get_resource(pdev, IORESOURCE_MEM, index);
    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;
}

static inline struct regmap *
ocelot_regmap_from_resource(struct platform_device *pdev, unsigned int index,
                const struct regmap_config *config)
{
    struct regmap *map;

    map = ocelot_regmap_from_resource_optional(pdev, index, config);
    return map ?: ERR_PTR(-ENOENT);
}

#endif