// SPDX-License-Identifier: GPL-2.0-only
/*
 * Layerscape SFP driver
 *
 * Copyright (c) 2022 Michael Walle <michael@walle.cc>
 *
 */

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

#define LAYERSCAPE_SFP_OTP_OFFSET       0x0200

struct layerscape_sfp_priv {
        struct regmap *regmap;
};

struct layerscape_sfp_data {
        int size;
        enum regmap_endian endian;
};

static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
                               size_t bytes)
{
        struct layerscape_sfp_priv *priv = context;

        return regmap_bulk_read(priv->regmap,
                                LAYERSCAPE_SFP_OTP_OFFSET + offset, val,
                                bytes / 4);
}

static struct nvmem_config layerscape_sfp_nvmem_config = {
        .name = "fsl-sfp",
        .reg_read = layerscape_sfp_read,
        .word_size = 4,
        .stride = 4,
};

static int layerscape_sfp_probe(struct platform_device *pdev)
{
        const struct layerscape_sfp_data *data;
        struct layerscape_sfp_priv *priv;
        struct nvmem_device *nvmem;
        struct regmap_config config = { 0 };
        void __iomem *base;

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

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        data = device_get_match_data(&pdev->dev);
        config.reg_bits = 32;
        config.reg_stride = 4;
        config.val_bits = 32;
        config.val_format_endian = data->endian;
        config.max_register = LAYERSCAPE_SFP_OTP_OFFSET + data->size - 4;
        priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &config);
        if (IS_ERR(priv->regmap))
                return PTR_ERR(priv->regmap);

        layerscape_sfp_nvmem_config.size = data->size;
        layerscape_sfp_nvmem_config.dev = &pdev->dev;
        layerscape_sfp_nvmem_config.priv = priv;

        nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);

        return PTR_ERR_OR_ZERO(nvmem);
}

static const struct layerscape_sfp_data ls1021a_data = {
        .size = 0x88,
        .endian = REGMAP_ENDIAN_BIG,
};

static const struct layerscape_sfp_data ls1028a_data = {
        .size = 0x88,
        .endian = REGMAP_ENDIAN_LITTLE,
};

static const struct of_device_id layerscape_sfp_dt_ids[] = {
        { .compatible = "fsl,ls1021a-sfp", .data = &ls1021a_data },
        { .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },
        {},
};
MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);

static struct platform_driver layerscape_sfp_driver = {
        .probe  = layerscape_sfp_probe,
        .driver = {
                .name   = "layerscape_sfp",
                .of_match_table = layerscape_sfp_dt_ids,
        },
};
module_platform_driver(layerscape_sfp_driver);

MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
MODULE_LICENSE("GPL");