// SPDX-License-Identifier: GPL-2.0
/*
 * RZ System controller driver
 *
 * Copyright (C) 2024 Renesas Electronics Corp.
 */

#include <linux/bitfield.h>
#include <linux/cleanup.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>

#include "rz-sysc.h"

/**
 * struct rz_sysc - RZ SYSC private data structure
 * @base: SYSC base address
 * @dev: SYSC device pointer
 */
struct rz_sysc {
        void __iomem *base;
        struct device *dev;
};

static int rz_sysc_soc_init(struct rz_sysc *sysc, const struct of_device_id *match)
{
        const struct rz_sysc_init_data *sysc_data = match->data;
        const struct rz_sysc_soc_id_init_data *soc_data = sysc_data->soc_id_init_data;
        struct soc_device_attribute *soc_dev_attr;
        const char *soc_id_start, *soc_id_end;
        u32 val, revision, specific_id;
        struct soc_device *soc_dev;
        char soc_id[32] = {0};
        size_t size;

        soc_id_start = strchr(match->compatible, ',') + 1;
        soc_id_end = strchr(match->compatible, '-');
        size = soc_id_end - soc_id_start + 1;
        if (size > 32)
                size = sizeof(soc_id);
        strscpy(soc_id, soc_id_start, size);

        soc_dev_attr = devm_kzalloc(sysc->dev, sizeof(*soc_dev_attr), GFP_KERNEL);
        if (!soc_dev_attr)
                return -ENOMEM;

        soc_dev_attr->family = devm_kstrdup(sysc->dev, soc_data->family, GFP_KERNEL);
        if (!soc_dev_attr->family)
                return -ENOMEM;

        soc_dev_attr->soc_id = devm_kstrdup(sysc->dev, soc_id, GFP_KERNEL);
        if (!soc_dev_attr->soc_id)
                return -ENOMEM;

        val = readl(sysc->base + soc_data->devid_offset);
        revision = field_get(soc_data->revision_mask, val);
        specific_id = field_get(soc_data->specific_id_mask, val);
        soc_dev_attr->revision = devm_kasprintf(sysc->dev, GFP_KERNEL, "%u", revision);
        if (!soc_dev_attr->revision)
                return -ENOMEM;

        if (soc_data->id && specific_id != soc_data->id) {
                dev_warn(sysc->dev, "SoC mismatch (product = 0x%x)\n", specific_id);
                return -ENODEV;
        }

        /* Try to call SoC-specific device identification */
        if (soc_data->print_id) {
                soc_data->print_id(sysc->dev, sysc->base, soc_dev_attr);
        } else {
                dev_info(sysc->dev, "Detected Renesas %s %s Rev %s\n",
                         soc_dev_attr->family, soc_dev_attr->soc_id, soc_dev_attr->revision);
        }

        soc_dev = soc_device_register(soc_dev_attr);
        if (IS_ERR(soc_dev))
                return PTR_ERR(soc_dev);

        return 0;
}

static const struct of_device_id rz_sysc_match[] = {
#ifdef CONFIG_SYSC_R9A08G045
        { .compatible = "renesas,r9a08g045-sysc", .data = &rzg3s_sysc_init_data },
#endif
#ifdef CONFIG_SYS_R9A09G047
        { .compatible = "renesas,r9a09g047-sys", .data = &rzg3e_sys_init_data },
#endif
#ifdef CONFIG_SYS_R9A09G056
        { .compatible = "renesas,r9a09g056-sys", .data = &rzv2n_sys_init_data },
#endif
#ifdef CONFIG_SYS_R9A09G057
        { .compatible = "renesas,r9a09g057-sys", .data = &rzv2h_sys_init_data },
#endif
        { }
};
MODULE_DEVICE_TABLE(of, rz_sysc_match);

static int rz_sysc_probe(struct platform_device *pdev)
{
        const struct rz_sysc_init_data *data;
        const struct of_device_id *match;
        struct device *dev = &pdev->dev;
        struct regmap *regmap;
        struct rz_sysc *sysc;
        int ret;

        struct regmap_config *regmap_cfg __free(kfree) = kzalloc_obj(*regmap_cfg);
        if (!regmap_cfg)
                return -ENOMEM;

        match = of_match_node(rz_sysc_match, dev->of_node);
        if (!match)
                return -ENODEV;

        data = match->data;

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

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

        sysc->dev = dev;
        ret = rz_sysc_soc_init(sysc, match);
        if (ret)
                return ret;

        regmap_cfg->name = "rz_sysc_regs";
        regmap_cfg->reg_bits = 32;
        regmap_cfg->reg_stride = 4;
        regmap_cfg->val_bits = 32;
        regmap_cfg->fast_io = true;
        regmap_cfg->max_register = data->max_register;
        regmap_cfg->readable_reg = data->readable_reg;
        regmap_cfg->writeable_reg = data->writeable_reg;

        regmap = devm_regmap_init_mmio(dev, sysc->base, regmap_cfg);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        return of_syscon_register_regmap(dev->of_node, regmap);
}

static struct platform_driver rz_sysc_driver = {
        .driver = {
                .name = "renesas-rz-sysc",
                .suppress_bind_attrs = true,
                .of_match_table = rz_sysc_match
        },
        .probe = rz_sysc_probe
};

static int __init rz_sysc_init(void)
{
        return platform_driver_register(&rz_sysc_driver);
}
subsys_initcall(rz_sysc_init);

MODULE_DESCRIPTION("Renesas RZ System Controller Driver");
MODULE_AUTHOR("Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>");
MODULE_LICENSE("GPL");