// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
 * Microsemi MIPS SoC support
 *
 * Copyright (c) 2017 Microsemi Corporation
 */
#include <linux/string.h>
#include <asm/machine.h>
#include <asm/prom.h>

#define DEVCPU_GCB_CHIP_REGS_CHIP_ID    0x71070000
#define CHIP_ID_PART_ID                 GENMASK(27, 12)

#define OCELOT_PART_ID                  (0x7514 << 12)

#define UART_UART                       0x70100000

static __init bool ocelot_detect(void)
{
        u32 rev;
        int idx;

        /* Look for the TLB entry set up by redboot before trying to use it */
        write_c0_entryhi(DEVCPU_GCB_CHIP_REGS_CHIP_ID);
        mtc0_tlbw_hazard();
        tlb_probe();
        tlb_probe_hazard();
        idx = read_c0_index();
        if (idx < 0)
                return false;

        /* A TLB entry exists, lets assume its usable and check the CHIP ID */
        rev = __raw_readl((void __iomem *)DEVCPU_GCB_CHIP_REGS_CHIP_ID);

        if ((rev & CHIP_ID_PART_ID) != OCELOT_PART_ID)
                return false;

        /* Copy command line from bootloader early for Initrd detection */
        if (fw_arg0 < 10 && (fw_arg1 & 0xFFF00000) == 0x80000000) {
                unsigned int prom_argc = fw_arg0;
                const char **prom_argv = (const char **)fw_arg1;

                if (prom_argc > 1 && strlen(prom_argv[1]) > 0)
                        /* ignore all built-in args if any f/w args given */
                        strscpy(arcs_cmdline, prom_argv[1]);
        }

        return true;
}

static void __init ocelot_earlyprintk_init(void)
{
        void __iomem *uart_base;

        uart_base = ioremap(UART_UART, 0x20);
        setup_8250_early_printk_port((unsigned long)uart_base, 2, 50000);
}

static void __init ocelot_late_init(void)
{
        ocelot_earlyprintk_init();
}

static __init const void *ocelot_fixup_fdt(const void *fdt,
                                           const void *match_data)
{
        /* This has to be done so late because ioremap needs to work */
        late_time_init = ocelot_late_init;

        return fdt;
}

extern char __dtb_ocelot_pcb123_begin[];

MIPS_MACHINE(ocelot) = {
        .fdt = __dtb_ocelot_pcb123_begin,
        .fixup_fdt = ocelot_fixup_fdt,
        .detect = ocelot_detect,
};