// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  RouterBoard 500 specific prom routines
 *
 *  Copyright (C) 2003, Peter Sadik <peter.sadik@idt.com>
 *  Copyright (C) 2005-2006, P.Christeas <p_christ@hol.gr>
 *  Copyright (C) 2007, Gabor Juhos <juhosg@openwrt.org>
 *                      Felix Fietkau <nbd@openwrt.org>
 *                      Florian Fainelli <florian@openwrt.org>
 */

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/console.h>
#include <linux/memblock.h>
#include <linux/ioport.h>

#include <asm/bootinfo.h>
#include <asm/mach-rc32434/ddr.h>
#include <asm/mach-rc32434/prom.h>

unsigned int idt_cpu_freq = 132000000;
EXPORT_SYMBOL(idt_cpu_freq);

static struct resource ddr_reg[] = {
        {
                .name = "ddr-reg",
                .start = DDR0_PHYS_ADDR,
                .end = DDR0_PHYS_ADDR + sizeof(struct ddr_ram),
                .flags = IORESOURCE_MEM,
        }
};

static inline int match_tag(char *arg, const char *tag)
{
        return strncmp(arg, tag, strlen(tag)) == 0;
}

static inline unsigned long tag2ul(char *arg, const char *tag)
{
        char *num;

        num = arg + strlen(tag);
        return simple_strtoul(num, 0, 10);
}

static void __init prom_setup_cmdline(void)
{
        static char cmd_line[COMMAND_LINE_SIZE] __initdata;
        char *cp, *board;
        int prom_argc;
        char **prom_argv;
        int i;
        size_t len;

        prom_argc = fw_arg0;
        prom_argv = (char **) fw_arg1;

        cp = cmd_line;
                /* Note: it is common that parameters start
                 * at argv[1] and not argv[0],
                 * however, our elf loader starts at [0] */
        for (i = 0; i < prom_argc; i++) {
                if (match_tag(prom_argv[i], FREQ_TAG)) {
                        idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG);
                        continue;
                }
#ifdef IGNORE_CMDLINE_MEM
                /* parses out the "mem=xx" arg */
                if (match_tag(prom_argv[i], MEM_TAG))
                        continue;
#endif
                if (i > 0)
                        *(cp++) = ' ';
                if (match_tag(prom_argv[i], BOARD_TAG)) {
                        board = prom_argv[i] + strlen(BOARD_TAG);

                        if (match_tag(board, BOARD_RB532A))
                                mips_machtype = MACH_MIKROTIK_RB532A;
                        else
                                mips_machtype = MACH_MIKROTIK_RB532;
                }

                len = strlen(prom_argv[i]);
                memcpy(cp, prom_argv[i], len + 1);
                cp += len;
        }
        *(cp++) = ' ';

        len = strlen(arcs_cmdline);
        if (len > 0) {
                *(cp++) = ' ';
                memcpy(cp, arcs_cmdline, len + 1);
                cp += len;
        }
        cmd_line[COMMAND_LINE_SIZE - 1] = '\0';
        strscpy(arcs_cmdline, cmd_line);
}

void __init prom_init(void)
{
        struct ddr_ram __iomem *ddr;
        phys_addr_t memsize;
        phys_addr_t ddrbase;

        ddr = ioremap(ddr_reg[0].start,
                        ddr_reg[0].end - ddr_reg[0].start);

        if (!ddr) {
                printk(KERN_ERR "Unable to remap DDR register\n");
                return;
        }

        ddrbase = (phys_addr_t)&ddr->ddrbase;
        memsize = (phys_addr_t)&ddr->ddrmask;
        memsize = 0 - memsize;

        prom_setup_cmdline();

        /* give all RAM to boot allocator,
         * except for the first 0x400 and the last 0x200 bytes */
        memblock_add(ddrbase + 0x400, memsize - 0x600);
}