/*
 * linux/arch/arm/mach-omap1/id.c
 *
 * OMAP1 CPU identification code
 *
 * Copyright (C) 2004 Nokia Corporation
 * Written by Tony Lindgren <tony@atomide.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <mach/cpu.h>

#define OMAP_DIE_ID_0           0xfffe1800
#define OMAP_DIE_ID_1           0xfffe1804
#define OMAP_PRODUCTION_ID_0    0xfffe2000
#define OMAP_PRODUCTION_ID_1    0xfffe2004
#define OMAP32_ID_0             0xfffed400
#define OMAP32_ID_1             0xfffed404

struct omap_id {
        u16     jtag_id;        /* Used to determine OMAP type */
        u8      die_rev;        /* Processor revision */
        u32     omap_id;        /* OMAP revision */
        u32     type;           /* Cpu id bits [31:08], cpu class bits [07:00] */
};

static unsigned int omap_revision;

/* Register values to detect the OMAP version */
static struct omap_id omap_ids[] __initdata = {
        { .jtag_id = 0xb574, .die_rev = 0x2, .omap_id = 0x03310315, .type = 0x03100000},
        { .jtag_id = 0x355f, .die_rev = 0x0, .omap_id = 0x03320000, .type = 0x07300100},
        { .jtag_id = 0xb55f, .die_rev = 0x0, .omap_id = 0x03320000, .type = 0x07300300},
        { .jtag_id = 0xb62c, .die_rev = 0x1, .omap_id = 0x03320500, .type = 0x08500000},
        { .jtag_id = 0xb470, .die_rev = 0x0, .omap_id = 0x03310100, .type = 0x15100000},
        { .jtag_id = 0xb576, .die_rev = 0x0, .omap_id = 0x03320000, .type = 0x16100000},
        { .jtag_id = 0xb576, .die_rev = 0x2, .omap_id = 0x03320100, .type = 0x16110000},
        { .jtag_id = 0xb576, .die_rev = 0x3, .omap_id = 0x03320100, .type = 0x16100c00},
        { .jtag_id = 0xb576, .die_rev = 0x0, .omap_id = 0x03320200, .type = 0x16100d00},
        { .jtag_id = 0xb613, .die_rev = 0x0, .omap_id = 0x03320300, .type = 0x1610ef00},
        { .jtag_id = 0xb613, .die_rev = 0x0, .omap_id = 0x03320300, .type = 0x1610ef00},
        { .jtag_id = 0xb576, .die_rev = 0x1, .omap_id = 0x03320100, .type = 0x16110000},
        { .jtag_id = 0xb58c, .die_rev = 0x2, .omap_id = 0x03320200, .type = 0x16110b00},
        { .jtag_id = 0xb58c, .die_rev = 0x3, .omap_id = 0x03320200, .type = 0x16110c00},
        { .jtag_id = 0xb65f, .die_rev = 0x0, .omap_id = 0x03320400, .type = 0x16212300},
        { .jtag_id = 0xb65f, .die_rev = 0x1, .omap_id = 0x03320400, .type = 0x16212300},
        { .jtag_id = 0xb65f, .die_rev = 0x1, .omap_id = 0x03320500, .type = 0x16212300},
        { .jtag_id = 0xb5f7, .die_rev = 0x0, .omap_id = 0x03330000, .type = 0x17100000},
        { .jtag_id = 0xb5f7, .die_rev = 0x1, .omap_id = 0x03330100, .type = 0x17100000},
        { .jtag_id = 0xb5f7, .die_rev = 0x2, .omap_id = 0x03330100, .type = 0x17100000},
};

unsigned int omap_rev(void)
{
        return omap_revision;
}
EXPORT_SYMBOL(omap_rev);

/*
 * Get OMAP type from PROD_ID.
 * 1710 has the PROD_ID in bits 15:00, not in 16:01 as documented in TRM.
 * 1510 PROD_ID is empty, and 1610 PROD_ID does not make sense.
 * Undocumented register in TEST BLOCK is used as fallback; This seems to
 * work on 1510, 1610 & 1710. The official way hopefully will work in future
 * processors.
 */
static u16 __init omap_get_jtag_id(void)
{
        u32 prod_id, omap_id;

        prod_id = omap_readl(OMAP_PRODUCTION_ID_1);
        omap_id = omap_readl(OMAP32_ID_1);

        /* Check for unusable OMAP_PRODUCTION_ID_1 on 1611B/5912 and 730/850 */
        if (((prod_id >> 20) == 0) || (prod_id == omap_id))
                prod_id = 0;
        else
                prod_id &= 0xffff;

        if (prod_id)
                return prod_id;

        /* Use OMAP32_ID_1 as fallback */
        prod_id = ((omap_id >> 12) & 0xffff);

        return prod_id;
}

/*
 * Get OMAP revision from DIE_REV.
 * Early 1710 processors may have broken OMAP_DIE_ID, it contains PROD_ID.
 * Undocumented register in the TEST BLOCK is used as fallback.
 * REVISIT: This does not seem to work on 1510
 */
static u8 __init omap_get_die_rev(void)
{
        u32 die_rev;

        die_rev = omap_readl(OMAP_DIE_ID_1);

        /* Check for broken OMAP_DIE_ID on early 1710 */
        if (((die_rev >> 12) & 0xffff) == omap_get_jtag_id())
                die_rev = 0;

        die_rev = (die_rev >> 17) & 0xf;
        if (die_rev)
                return die_rev;

        die_rev = (omap_readl(OMAP32_ID_1) >> 28) & 0xf;

        return die_rev;
}

void __init omap_check_revision(void)
{
        int i;
        u16 jtag_id;
        u8 die_rev;
        u32 omap_id;
        u8 cpu_type;

        jtag_id = omap_get_jtag_id();
        die_rev = omap_get_die_rev();
        omap_id = omap_readl(OMAP32_ID_0);

#ifdef DEBUG
        printk(KERN_DEBUG "OMAP_DIE_ID_0: 0x%08x\n", omap_readl(OMAP_DIE_ID_0));
        printk(KERN_DEBUG "OMAP_DIE_ID_1: 0x%08x DIE_REV: %i\n",
                omap_readl(OMAP_DIE_ID_1),
               (omap_readl(OMAP_DIE_ID_1) >> 17) & 0xf);
        printk(KERN_DEBUG "OMAP_PRODUCTION_ID_0: 0x%08x\n",
                omap_readl(OMAP_PRODUCTION_ID_0));
        printk(KERN_DEBUG "OMAP_PRODUCTION_ID_1: 0x%08x JTAG_ID: 0x%04x\n",
                omap_readl(OMAP_PRODUCTION_ID_1),
                omap_readl(OMAP_PRODUCTION_ID_1) & 0xffff);
        printk(KERN_DEBUG "OMAP32_ID_0: 0x%08x\n", omap_readl(OMAP32_ID_0));
        printk(KERN_DEBUG "OMAP32_ID_1: 0x%08x\n", omap_readl(OMAP32_ID_1));
        printk(KERN_DEBUG "JTAG_ID: 0x%04x DIE_REV: %i\n", jtag_id, die_rev);
#endif

        system_serial_high = omap_readl(OMAP_DIE_ID_0);
        system_serial_low = omap_readl(OMAP_DIE_ID_1);

        /* First check only the major version in a safe way */
        for (i = 0; i < ARRAY_SIZE(omap_ids); i++) {
                if (jtag_id == (omap_ids[i].jtag_id)) {
                        omap_revision = omap_ids[i].type;
                        break;
                }
        }

        /* Check if we can find the die revision */
        for (i = 0; i < ARRAY_SIZE(omap_ids); i++) {
                if (jtag_id == omap_ids[i].jtag_id && die_rev == omap_ids[i].die_rev) {
                        omap_revision = omap_ids[i].type;
                        break;
                }
        }

        /* Finally check also the omap_id */
        for (i = 0; i < ARRAY_SIZE(omap_ids); i++) {
                if (jtag_id == omap_ids[i].jtag_id
                    && die_rev == omap_ids[i].die_rev
                    && omap_id == omap_ids[i].omap_id) {
                        omap_revision = omap_ids[i].type;
                        break;
                }
        }

        /* Add the cpu class info (7xx, 15xx, 16xx, 24xx) */
        cpu_type = omap_revision >> 24;

        switch (cpu_type) {
        case 0x07:
        case 0x08:
                omap_revision |= 0x07;
                break;
        case 0x03:
        case 0x15:
                omap_revision |= 0x15;
                break;
        case 0x16:
        case 0x17:
                omap_revision |= 0x16;
                break;
        default:
                printk(KERN_INFO "Unknown OMAP cpu type: 0x%02x\n", cpu_type);
        }

        printk(KERN_INFO "OMAP%04x", omap_revision >> 16);
        if ((omap_revision >> 8) & 0xff)
                printk(KERN_INFO "%x", (omap_revision >> 8) & 0xff);
        printk(KERN_INFO " revision %i handled as %02xxx id: %08x%08x\n",
               die_rev, omap_revision & 0xff, system_serial_low,
               system_serial_high);
}