// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright 2019 IBM Corp. */

#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>

static struct {
        const char *name;
        const u32 id;
} const rev_table[] = {
        /* AST2400 */
        { "AST2400", 0x02000303 },
        { "AST1400", 0x02010103 },
        { "AST1250", 0x02010303 },
        /* AST2500 */
        { "AST2500", 0x04000303 },
        { "AST2510", 0x04000103 },
        { "AST2520", 0x04000203 },
        { "AST2530", 0x04000403 },
        /* AST2600 */
        { "AST2600", 0x05000303 },
        { "AST2620", 0x05010203 },
        { "AST2605", 0x05030103 },
        { "AST2625", 0x05030403 },
        /* AST2700 */
        { "AST2750", 0x06000003 },
        { "AST2700", 0x06000103 },
        { "AST2720", 0x06000203 },
};

static const char *siliconid_to_name(u32 siliconid)
{
        unsigned int id = siliconid & 0xff00ffff;
        unsigned int i;

        for (i = 0 ; i < ARRAY_SIZE(rev_table) ; ++i) {
                if ((rev_table[i].id & 0xff00ffff) == id)
                        return rev_table[i].name;
        }

        return "Unknown";
}

static const char *siliconid_to_rev(u32 siliconid)
{
        unsigned int rev = (siliconid >> 16) & 0xff;
        unsigned int gen = (siliconid >> 24) & 0xff;

        if (gen < 0x5) {
                /* AST2500 and below */
                switch (rev) {
                case 0:
                        return "A0";
                case 1:
                        return "A1";
                case 3:
                        return "A2";
                }
        } else {
                /* AST2600 */
                switch (rev) {
                case 0:
                        return "A0";
                case 1:
                        return "A1";
                case 2:
                        return "A2";
                case 3:
                        return "A3";
                }
        }

        return "??";
}

static int __init aspeed_socinfo_init(void)
{
        struct soc_device_attribute *attrs;
        struct soc_device *soc_dev;
        struct device_node *np;
        void __iomem *reg;
        bool has_chipid = false;
        u32 siliconid;
        u32 chipid[2];
        const char *machine = NULL;

        np = of_find_compatible_node(NULL, NULL, "aspeed,silicon-id");
        if (!of_device_is_available(np)) {
                of_node_put(np);
                return -ENODEV;
        }

        reg = of_iomap(np, 0);
        if (!reg) {
                of_node_put(np);
                return -ENODEV;
        }
        siliconid = readl(reg);
        iounmap(reg);

        /* This is optional, the ast2400 does not have it */
        reg = of_iomap(np, 1);
        if (reg) {
                has_chipid = true;
                chipid[0] = readl(reg);
                chipid[1] = readl(reg + 4);
                iounmap(reg);
        }
        of_node_put(np);

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

        /*
         * Machine: Romulus BMC
         * Family: AST2500
         * Revision: A1
         * SoC ID: raw silicon revision id
         * Serial Number: 64-bit chipid
         */

        np = of_find_node_by_path("/");
        of_property_read_string(np, "model", &machine);
        if (machine)
                attrs->machine = kstrdup(machine, GFP_KERNEL);
        of_node_put(np);

        attrs->family = siliconid_to_name(siliconid);
        attrs->revision = siliconid_to_rev(siliconid);
        attrs->soc_id = kasprintf(GFP_KERNEL, "%08x", siliconid);

        if (has_chipid)
                attrs->serial_number = kasprintf(GFP_KERNEL, "%08x%08x",
                                                 chipid[1], chipid[0]);

        soc_dev = soc_device_register(attrs);
        if (IS_ERR(soc_dev)) {
                kfree(attrs->machine);
                kfree(attrs->soc_id);
                kfree(attrs->serial_number);
                kfree(attrs);
                return PTR_ERR(soc_dev);
        }

        pr_info("ASPEED %s rev %s (%s)\n",
                        attrs->family,
                        attrs->revision,
                        attrs->soc_id);

        return 0;
}
early_initcall(aspeed_socinfo_init);