// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/sys_soc.h>

#include <asm/cputype.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mach/map.h>

/**
 * struct dbx500_asic_id - fields of the ASIC ID
 * @process: the manufacturing process, 0x40 is 40 nm 0x00 is "standard"
 * @partnumber: hithereto 0x8500 for DB8500
 * @revision: version code in the series
 */
struct dbx500_asic_id {
        u16     partnumber;
        u8      revision;
        u8      process;
};

static struct dbx500_asic_id dbx500_id;

static unsigned int __init ux500_read_asicid(phys_addr_t addr)
{
        void __iomem *virt = ioremap(addr, 4);
        unsigned int asicid;

        if (!virt)
                return 0;

        asicid = readl(virt);
        iounmap(virt);

        return asicid;
}

static void ux500_print_soc_info(unsigned int asicid)
{
        unsigned int rev = dbx500_id.revision;

        pr_info("DB%4x ", dbx500_id.partnumber);

        if (rev == 0x01)
                pr_cont("Early Drop");
        else if (rev >= 0xA0)
                pr_cont("v%d.%d" , (rev >> 4) - 0xA + 1, rev & 0xf);
        else
                pr_cont("Unknown");

        pr_cont(" [%#010x]\n", asicid);
}

static unsigned int partnumber(unsigned int asicid)
{
        return (asicid >> 8) & 0xffff;
}

/*
 * SOC          MIDR            ASICID ADDRESS          ASICID VALUE
 * DB8500ed     0x410fc090      0x9001FFF4              0x00850001
 * DB8500v1     0x411fc091      0x9001FFF4              0x008500A0
 * DB8500v1.1   0x411fc091      0x9001FFF4              0x008500A1
 * DB8500v2     0x412fc091      0x9001DBF4              0x008500B0
 * DB8520v2.2   0x412fc091      0x9001DBF4              0x008500B2
 * DB5500v1     0x412fc091      0x9001FFF4              0x005500A0
 * DB9540       0x413fc090      0xFFFFDBF4              0x009540xx
 */

static void __init ux500_setup_id(void)
{
        unsigned int cpuid = read_cpuid_id();
        unsigned int asicid = 0;
        phys_addr_t addr = 0;

        switch (cpuid) {
        case 0x410fc090: /* DB8500ed */
        case 0x411fc091: /* DB8500v1 */
                addr = 0x9001FFF4;
                break;

        case 0x412fc091: /* DB8520 / DB8500v2 / DB5500v1 */
                asicid = ux500_read_asicid(0x9001DBF4);
                if (partnumber(asicid) == 0x8500 ||
                    partnumber(asicid) == 0x8520)
                        /* DB8500v2 */
                        break;

                /* DB5500v1 */
                addr = 0x9001FFF4;
                break;

        case 0x413fc090: /* DB9540 */
                addr = 0xFFFFDBF4;
                break;
        }

        if (addr)
                asicid = ux500_read_asicid(addr);

        if (!asicid) {
                pr_err("Unable to identify SoC\n");
                BUG();
        }

        dbx500_id.process = asicid >> 24;
        dbx500_id.partnumber = partnumber(asicid);
        dbx500_id.revision = asicid & 0xff;

        ux500_print_soc_info(asicid);
}

static const char * __init ux500_get_machine(void)
{
        return kasprintf(GFP_KERNEL, "DB%4x", dbx500_id.partnumber);
}

static const char * __init ux500_get_family(void)
{
        return kasprintf(GFP_KERNEL, "ux500");
}

static const char * __init ux500_get_revision(void)
{
        unsigned int rev = dbx500_id.revision;

        if (rev == 0x01)
                return kasprintf(GFP_KERNEL, "%s", "ED");
        else if (rev >= 0xA0)
                return kasprintf(GFP_KERNEL, "%d.%d",
                                 (rev >> 4) - 0xA + 1, rev & 0xf);

        return kasprintf(GFP_KERNEL, "%s", "Unknown");
}

static ssize_t
process_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        if (dbx500_id.process == 0x00)
                return sprintf(buf, "Standard\n");

        return sprintf(buf, "%02xnm\n", dbx500_id.process);
}

static DEVICE_ATTR_RO(process);

static struct attribute *ux500_soc_attrs[] = {
        &dev_attr_process.attr,
        NULL
};

ATTRIBUTE_GROUPS(ux500_soc);

static const char *db8500_read_soc_id(struct device_node *backupram)
{
        void __iomem *base;
        const char *retstr;
        u32 uid[5];

        base = of_iomap(backupram, 0);
        if (!base)
                return NULL;
        memcpy_fromio(uid, base + 0x1fc0, sizeof(uid));

        /* Throw these device-specific numbers into the entropy pool */
        add_device_randomness(uid, sizeof(uid));
        retstr = kasprintf(GFP_KERNEL, "%08x%08x%08x%08x%08x",
                           uid[0], uid[1], uid[2], uid[3], uid[4]);
        iounmap(base);
        return retstr;
}

static void __init soc_info_populate(struct soc_device_attribute *soc_dev_attr,
                                     struct device_node *backupram)
{
        soc_dev_attr->soc_id   = db8500_read_soc_id(backupram);
        soc_dev_attr->machine  = ux500_get_machine();
        soc_dev_attr->family   = ux500_get_family();
        soc_dev_attr->revision = ux500_get_revision();
        soc_dev_attr->custom_attr_group = ux500_soc_groups[0];
}

static int __init ux500_soc_device_init(void)
{
        struct soc_device *soc_dev;
        struct soc_device_attribute *soc_dev_attr;
        struct device_node *backupram;

        backupram = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram");
        if (!backupram)
                return 0;

        ux500_setup_id();

        soc_dev_attr = kzalloc_obj(*soc_dev_attr);
        if (!soc_dev_attr) {
                of_node_put(backupram);
                return -ENOMEM;
        }

        soc_info_populate(soc_dev_attr, backupram);
        of_node_put(backupram);

        soc_dev = soc_device_register(soc_dev_attr);
        if (IS_ERR(soc_dev)) {
                kfree(soc_dev_attr);
                return PTR_ERR(soc_dev);
        }

        return 0;
}
subsys_initcall(ux500_soc_device_init);