// SPDX-License-Identifier: GPL-2.0
/*
 * R-Car Generation 2 support
 *
 * Copyright (C) 2013  Renesas Solutions Corp.
 * Copyright (C) 2013  Magnus Damm
 * Copyright (C) 2014  Ulrich Hecht
 */

#include <linux/clocksource.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_clk.h>
#include <linux/psci.h>
#include <asm/mach/arch.h>
#include <asm/secure_cntvoff.h>
#include "common.h"

static const struct of_device_id cpg_matches[] __initconst = {
        { .compatible = "renesas,r8a7742-cpg-mssr", .data = "extal" },
        { .compatible = "renesas,r8a7743-cpg-mssr", .data = "extal" },
        { .compatible = "renesas,r8a7744-cpg-mssr", .data = "extal" },
        { .compatible = "renesas,r8a7790-cpg-mssr", .data = "extal" },
        { .compatible = "renesas,r8a7791-cpg-mssr", .data = "extal" },
        { .compatible = "renesas,r8a7793-cpg-mssr", .data = "extal" },
        { /* sentinel */ }
};

static unsigned int __init get_extal_freq(void)
{
        const struct of_device_id *match;
        struct device_node *cpg, *extal;
        u32 freq = 20000000;
        int idx = 0;

        cpg = of_find_matching_node_and_match(NULL, cpg_matches, &match);
        if (!cpg)
                return freq;

        if (match->data)
                idx = of_property_match_string(cpg, "clock-names", match->data);
        extal = of_parse_phandle(cpg, "clocks", idx);
        of_node_put(cpg);
        if (!extal)
                return freq;

        of_property_read_u32(extal, "clock-frequency", &freq);
        of_node_put(extal);
        return freq;
}

#define CNTCR 0
#define CNTFID0 0x20

static void __init rcar_gen2_timer_init(void)
{
        bool need_update = true;
        void __iomem *base;
        u32 freq;

        /*
         * If PSCI is available then most likely we are running on PSCI-enabled
         * U-Boot which, we assume, has already taken care of resetting CNTVOFF
         * and updating counter module before switching to non-secure mode
         * and we don't need to.
         */
#ifdef CONFIG_ARM_PSCI_FW
        if (psci_ops.cpu_on)
                need_update = false;
#endif

        if (need_update == false)
                goto skip_update;

        secure_cntvoff_init();

        if (of_machine_is_compatible("renesas,r8a7745") ||
            of_machine_is_compatible("renesas,r8a77470") ||
            of_machine_is_compatible("renesas,r8a7792") ||
            of_machine_is_compatible("renesas,r8a7794")) {
                freq = 260000000 / 8;   /* ZS / 8 */
        } else {
                /* At Linux boot time the r8a7790 arch timer comes up
                 * with the counter disabled. Moreover, it may also report
                 * a potentially incorrect fixed 13 MHz frequency. To be
                 * correct these registers need to be updated to use the
                 * frequency EXTAL / 2.
                 */
                freq = get_extal_freq() / 2;
        }

        /* Remap "armgcnt address map" space */
        base = ioremap(0xe6080000, PAGE_SIZE);

        /*
         * Update the timer if it is either not running, or is not at the
         * right frequency. The timer is only configurable in secure mode
         * so this avoids an abort if the loader started the timer and
         * entered the kernel in non-secure mode.
         */

        if ((ioread32(base + CNTCR) & 1) == 0 ||
            ioread32(base + CNTFID0) != freq) {
                /* Update registers with correct frequency */
                iowrite32(freq, base + CNTFID0);
                asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));

                /* make sure arch timer is started by setting bit 0 of CNTCR */
                iowrite32(1, base + CNTCR);
        }

        iounmap(base);

skip_update:
        of_clk_init(NULL);
        timer_probe();
}

static const char * const rcar_gen2_boards_compat_dt[] __initconst = {
        "renesas,r8a7790",
        "renesas,r8a7791",
        "renesas,r8a7792",
        "renesas,r8a7793",
        "renesas,r8a7794",
        NULL
};

DT_MACHINE_START(RCAR_GEN2_DT, "Generic R-Car Gen2 (Flattened Device Tree)")
        .init_late      = shmobile_init_late,
        .init_time      = rcar_gen2_timer_init,
        .dt_compat      = rcar_gen2_boards_compat_dt,
MACHINE_END

static const char * const rz_g1_boards_compat_dt[] __initconst = {
        "renesas,r8a7742",
        "renesas,r8a7743",
        "renesas,r8a7744",
        "renesas,r8a7745",
        "renesas,r8a77470",
        NULL
};

DT_MACHINE_START(RZ_G1_DT, "Generic RZ/G1 (Flattened Device Tree)")
        .init_late      = shmobile_init_late,
        .init_time      = rcar_gen2_timer_init,
        .dt_compat      = rz_g1_boards_compat_dt,
MACHINE_END