/*
 * Copyright (c) 2017 BayLibre, SAS
 * Author: Neil Armstrong <narmstrong@baylibre.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 AO_SEC_SD_CFG8          0xe0
#define AO_SEC_SOCINFO_OFFSET   AO_SEC_SD_CFG8

#define SOCINFO_MAJOR   GENMASK(31, 24)
#define SOCINFO_PACK    GENMASK(23, 16)
#define SOCINFO_MINOR   GENMASK(15, 8)
#define SOCINFO_MISC    GENMASK(7, 0)

static const struct meson_gx_soc_id {
        const char *name;
        unsigned int id;
} soc_ids[] = {
        { "GXBB", 0x1f },
        { "GXTVBB", 0x20 },
        { "GXL", 0x21 },
        { "GXM", 0x22 },
        { "TXL", 0x23 },
        { "TXLX", 0x24 },
        { "AXG", 0x25 },
        { "GXLX", 0x26 },
        { "TXHD", 0x27 },
        { "G12A", 0x28 },
        { "G12B", 0x29 },
        { "SM1", 0x2b },
        { "A1", 0x2c },
        { "T7", 0x36 },
        { "S4", 0x37 },
        { "A5", 0x3c },
        { "C3", 0x3d },
        { "A4", 0x40 },
        { "S7", 0x46 },
        { "S7D", 0x47 },
        { "S6", 0x48 },
};

static const struct meson_gx_package_id {
        const char *name;
        unsigned int major_id;
        unsigned int pack_id;
        unsigned int pack_mask;
} soc_packages[] = {
        { "S905", 0x1f, 0, 0x20 }, /* pack_id != 0x20 */
        { "S905H", 0x1f, 0x3, 0xf }, /* pack_id & 0xf == 0x3 */
        { "S905M", 0x1f, 0x20, 0xf0 }, /* pack_id == 0x20 */
        { "S905D", 0x21, 0, 0xf0 },
        { "S905X", 0x21, 0x80, 0xf0 },
        { "S905W", 0x21, 0xa0, 0xf0 },
        { "S905L", 0x21, 0xc0, 0xf0 },
        { "S905M2", 0x21, 0xe0, 0xf0 },
        { "S805X", 0x21, 0x30, 0xf0 },
        { "S805Y", 0x21, 0xb0, 0xf0 },
        { "S912", 0x22, 0, 0x0 }, /* Only S912 is known for GXM */
        { "962X", 0x24, 0x10, 0xf0 },
        { "962E", 0x24, 0x20, 0xf0 },
        { "A113X", 0x25, 0x37, 0xff },
        { "A113X", 0x25, 0x43, 0xff },
        { "A113D", 0x25, 0x22, 0xff },
        { "S905L", 0x26, 0, 0x0 },
        { "S905D2", 0x28, 0x10, 0xf0 },
        { "S905Y2", 0x28, 0x30, 0xf0 },
        { "S905X2", 0x28, 0x40, 0xf0 },
        { "A311D", 0x29, 0x10, 0xf0 },
        { "S922X", 0x29, 0x40, 0xf0 },
        { "S905D3", 0x2b, 0x4, 0xf5 },
        { "S905X3", 0x2b, 0x5, 0xf5 },
        { "S905X3", 0x2b, 0x10, 0x3f },
        { "S905D3", 0x2b, 0x30, 0x3f },
        { "A113L", 0x2c, 0x0, 0xf8 },
        { "S805X2", 0x37, 0x2, 0xf },
        { "S905Y4", 0x37, 0x3, 0xf },
        { "C308L", 0x3d, 0x1, 0xf },
        { "A311D2", 0x36, 0x1, 0xf },
        { "A113X2", 0x3c, 0x1, 0xf },
        { "A113L2", 0x40, 0x1, 0xf },
        { "S805X3", 0x46, 0x3, 0xf },
        { "S905X5M", 0x47, 0x1, 0xf },
        { "S905X5", 0x48, 0x1, 0xf },
};

static inline unsigned int socinfo_to_major(u32 socinfo)
{
        return FIELD_GET(SOCINFO_MAJOR, socinfo);
}

static inline unsigned int socinfo_to_minor(u32 socinfo)
{
        return FIELD_GET(SOCINFO_MINOR, socinfo);
}

static inline unsigned int socinfo_to_pack(u32 socinfo)
{
        return FIELD_GET(SOCINFO_PACK, socinfo);
}

static inline unsigned int socinfo_to_misc(u32 socinfo)
{
        return FIELD_GET(SOCINFO_MISC, socinfo);
}

static const char *socinfo_to_package_id(u32 socinfo)
{
        unsigned int pack = socinfo_to_pack(socinfo);
        unsigned int major = socinfo_to_major(socinfo);
        int i;

        for (i = 0 ; i < ARRAY_SIZE(soc_packages) ; ++i) {
                if (soc_packages[i].major_id == major &&
                    soc_packages[i].pack_id ==
                                (pack & soc_packages[i].pack_mask))
                        return soc_packages[i].name;
        }

        return "Unknown";
}

static const char *socinfo_to_soc_id(u32 socinfo)
{
        unsigned int id = socinfo_to_major(socinfo);
        int i;

        for (i = 0 ; i < ARRAY_SIZE(soc_ids) ; ++i) {
                if (soc_ids[i].id == id)
                        return soc_ids[i].name;
        }

        return "Unknown";
}

static int __init meson_gx_socinfo_init(void)
{
        struct soc_device_attribute *soc_dev_attr;
        struct soc_device *soc_dev;
        struct device_node *np;
        struct regmap *regmap;
        unsigned int socinfo;
        struct device *dev;
        int ret;

        /* look up for chipid node */
        np = of_find_compatible_node(NULL, NULL, "amlogic,meson-gx-ao-secure");
        if (!np)
                return -ENODEV;

        /* check if interface is enabled */
        if (!of_device_is_available(np)) {
                of_node_put(np);
                return -ENODEV;
        }

        /* check if chip-id is available */
        if (!of_property_read_bool(np, "amlogic,has-chip-id")) {
                of_node_put(np);
                return -ENODEV;
        }

        /* node should be a syscon */
        regmap = syscon_node_to_regmap(np);
        of_node_put(np);
        if (IS_ERR(regmap)) {
                pr_err("%s: failed to get regmap\n", __func__);
                return -ENODEV;
        }

        ret = regmap_read(regmap, AO_SEC_SOCINFO_OFFSET, &socinfo);
        if (ret < 0)
                return ret;

        if (!socinfo) {
                pr_err("%s: invalid chipid value\n", __func__);
                return -EINVAL;
        }

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

        soc_dev_attr->family = "Amlogic Meson";
        soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x:%x - %x:%x",
                                           socinfo_to_major(socinfo),
                                           socinfo_to_minor(socinfo),
                                           socinfo_to_pack(socinfo),
                                           socinfo_to_misc(socinfo));
        soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "%s (%s)",
                                         socinfo_to_soc_id(socinfo),
                                         socinfo_to_package_id(socinfo));

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

        dev_info(dev, "Amlogic Meson %s Revision %x:%x (%x:%x) Detected\n",
                        soc_dev_attr->soc_id,
                        socinfo_to_major(socinfo),
                        socinfo_to_minor(socinfo),
                        socinfo_to_pack(socinfo),
                        socinfo_to_misc(socinfo));

        return 0;
}
device_initcall(meson_gx_socinfo_init);