/*
 * Copyright (c) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
 *
 * SPDX-License-Identifier: GPL-2.0+
 */

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

#define MESON_SOCINFO_MAJOR_VER_MESON6          0x16
#define MESON_SOCINFO_MAJOR_VER_MESON8          0x19
#define MESON_SOCINFO_MAJOR_VER_MESON8B         0x1b

#define MESON_MX_ASSIST_HW_REV                  0x14c

#define MESON_MX_ANALOG_TOP_METAL_REVISION      0x0

#define MESON_MX_BOOTROM_MISC_VER               0x4

static const char *meson_mx_socinfo_revision(unsigned int major_ver,
                                             unsigned int misc_ver,
                                             unsigned int metal_rev)
{
        unsigned int minor_ver;

        switch (major_ver) {
        case MESON_SOCINFO_MAJOR_VER_MESON6:
                minor_ver = 0xa;
                break;

        case MESON_SOCINFO_MAJOR_VER_MESON8:
                if (metal_rev == 0x11111112)
                        major_ver = 0x1d;

                if (metal_rev == 0x11111111 || metal_rev == 0x11111112)
                        minor_ver = 0xa;
                else if (metal_rev == 0x11111113)
                        minor_ver = 0xb;
                else if (metal_rev == 0x11111133)
                        minor_ver = 0xc;
                else
                        minor_ver = 0xd;

                break;

        case MESON_SOCINFO_MAJOR_VER_MESON8B:
                if (metal_rev == 0x11111111)
                        minor_ver = 0xa;
                else
                        minor_ver = 0xb;

                break;

        default:
                minor_ver = 0x0;
                break;
        }

        return kasprintf(GFP_KERNEL, "Rev%X (%x - 0:%X)", minor_ver, major_ver,
                         misc_ver);
}

static const char *meson_mx_socinfo_soc_id(unsigned int major_ver,
                                           unsigned int metal_rev)
{
        const char *soc_id;

        switch (major_ver) {
        case MESON_SOCINFO_MAJOR_VER_MESON6:
                soc_id = "Meson6 (AML8726-MX)";
                break;

        case MESON_SOCINFO_MAJOR_VER_MESON8:
                if (metal_rev == 0x11111112)
                        soc_id = "Meson8m2 (S812)";
                else
                        soc_id = "Meson8 (S802)";

                break;

        case MESON_SOCINFO_MAJOR_VER_MESON8B:
                soc_id = "Meson8b (S805)";
                break;

        default:
                soc_id = "Unknown";
                break;
        }

        return kstrdup_const(soc_id, GFP_KERNEL);
}

static const struct of_device_id meson_mx_socinfo_analog_top_ids[] = {
        { .compatible = "amlogic,meson8-analog-top", },
        { .compatible = "amlogic,meson8b-analog-top", },
        { /* sentinel */ }
};

static int __init meson_mx_socinfo_init(void)
{
        struct soc_device_attribute *soc_dev_attr;
        struct soc_device *soc_dev;
        struct device_node *np;
        struct regmap *assist_regmap, *bootrom_regmap, *analog_top_regmap;
        unsigned int major_ver, misc_ver, metal_rev = 0;
        int ret;

        assist_regmap =
                syscon_regmap_lookup_by_compatible("amlogic,meson-mx-assist");
        if (IS_ERR(assist_regmap))
                return PTR_ERR(assist_regmap);

        bootrom_regmap =
                syscon_regmap_lookup_by_compatible("amlogic,meson-mx-bootrom");
        if (IS_ERR(bootrom_regmap))
                return PTR_ERR(bootrom_regmap);

        np = of_find_matching_node(NULL, meson_mx_socinfo_analog_top_ids);
        if (np) {
                analog_top_regmap = syscon_node_to_regmap(np);
                of_node_put(np);
                if (IS_ERR(analog_top_regmap))
                        return PTR_ERR(analog_top_regmap);

                ret = regmap_read(analog_top_regmap,
                                  MESON_MX_ANALOG_TOP_METAL_REVISION,
                                  &metal_rev);
                if (ret)
                        return ret;
        }

        ret = regmap_read(assist_regmap, MESON_MX_ASSIST_HW_REV, &major_ver);
        if (ret < 0)
                return ret;

        ret = regmap_read(bootrom_regmap, MESON_MX_BOOTROM_MISC_VER,
                          &misc_ver);
        if (ret < 0)
                return ret;

        soc_dev_attr = kzalloc_obj(*soc_dev_attr);
        if (!soc_dev_attr)
                return -ENODEV;

        soc_dev_attr->family = "Amlogic Meson";

        np = of_find_node_by_path("/");
        of_property_read_string(np, "model", &soc_dev_attr->machine);
        of_node_put(np);

        soc_dev_attr->revision = meson_mx_socinfo_revision(major_ver, misc_ver,
                                                           metal_rev);
        soc_dev_attr->soc_id = meson_mx_socinfo_soc_id(major_ver, metal_rev);

        soc_dev = soc_device_register(soc_dev_attr);
        if (IS_ERR(soc_dev)) {
                kfree_const(soc_dev_attr->revision);
                kfree_const(soc_dev_attr->soc_id);
                kfree(soc_dev_attr);
                return PTR_ERR(soc_dev);
        }

        dev_info(soc_device_to_device(soc_dev), "Amlogic %s %s detected\n",
                 soc_dev_attr->soc_id, soc_dev_attr->revision);

        return 0;
}
device_initcall(meson_mx_socinfo_init);