// SPDX-License-Identifier: GPL-2.0-only
/*
 * UniPhier eFuse driver
 *
 * Copyright (C) 2017 Socionext Inc.
 */

#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>

struct uniphier_efuse_priv {
        void __iomem *base;
};

static int uniphier_reg_read(void *context,
                             unsigned int reg, void *_val, size_t bytes)
{
        struct uniphier_efuse_priv *priv = context;
        u8 *val = _val;
        int offs;

        for (offs = 0; offs < bytes; offs += sizeof(u8))
                *val++ = readb(priv->base + reg + offs);

        return 0;
}

static int uniphier_efuse_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct resource *res;
        struct nvmem_device *nvmem;
        struct nvmem_config econfig = {};
        struct uniphier_efuse_priv *priv;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
        if (IS_ERR(priv->base))
                return PTR_ERR(priv->base);

        econfig.stride = 1;
        econfig.word_size = 1;
        econfig.read_only = true;
        econfig.reg_read = uniphier_reg_read;
        econfig.size = resource_size(res);
        econfig.priv = priv;
        econfig.dev = dev;
        econfig.add_legacy_fixed_of_cells = true;
        nvmem = devm_nvmem_register(dev, &econfig);

        return PTR_ERR_OR_ZERO(nvmem);
}

static const struct of_device_id uniphier_efuse_of_match[] = {
        { .compatible = "socionext,uniphier-efuse",},
        {/* sentinel */},
};
MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);

static struct platform_driver uniphier_efuse_driver = {
        .probe = uniphier_efuse_probe,
        .driver = {
                .name = "uniphier-efuse",
                .of_match_table = uniphier_efuse_of_match,
        },
};
module_platform_driver(uniphier_efuse_driver);

MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
MODULE_DESCRIPTION("UniPhier eFuse driver");
MODULE_LICENSE("GPL v2");