root/arch/arm/mach-exynos/exynos.c
// SPDX-License-Identifier: GPL-2.0
//
// Samsung Exynos Flattened Device Tree enabled machine
//
// Copyright (c) 2010-2014 Samsung Electronics Co., Ltd.
//              http://www.samsung.com

#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_fdt.h>
#include <linux/platform_device.h>
#include <linux/irqchip.h>
#include <linux/soc/samsung/exynos-regs-pmu.h>

#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>

#include "common.h"

#define S3C_ADDR_BASE   0xF6000000
#define S3C_ADDR(x)     ((void __iomem __force *)S3C_ADDR_BASE + (x))
#define S5P_VA_CHIPID   S3C_ADDR(0x02000000)

static struct platform_device exynos_cpuidle = {
        .name              = "exynos_cpuidle",
#ifdef CONFIG_ARM_EXYNOS_CPUIDLE
        .dev.platform_data = exynos_enter_aftr,
#endif
        .id                = -1,
};

void __iomem *sysram_base_addr __ro_after_init;
phys_addr_t sysram_base_phys __ro_after_init;
void __iomem *sysram_ns_base_addr __ro_after_init;

unsigned long exynos_cpu_id;
static unsigned int exynos_cpu_rev;

unsigned int exynos_rev(void)
{
        return exynos_cpu_rev;
}

void __init exynos_sysram_init(void)
{
        for_each_compatible_node_scoped(node, NULL, "samsung,exynos4210-sysram") {
                struct resource res;
                if (!of_device_is_available(node))
                        continue;

                of_address_to_resource(node, 0, &res);
                sysram_base_addr = ioremap(res.start, resource_size(&res));
                sysram_base_phys = res.start;
                break;
        }

        for_each_compatible_node_scoped(node, NULL, "samsung,exynos4210-sysram-ns") {
                if (!of_device_is_available(node))
                        continue;
                sysram_ns_base_addr = of_iomap(node, 0);
                break;
        }
}

static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
                                        int depth, void *data)
{
        struct map_desc iodesc;
        const __be32 *reg;
        int len;

        if (!of_flat_dt_is_compatible(node, "samsung,exynos4210-chipid"))
                return 0;

        reg = of_get_flat_dt_prop(node, "reg", &len);
        if (reg == NULL || len != (sizeof(unsigned long) * 2))
                return 0;

        iodesc.pfn = __phys_to_pfn(be32_to_cpu(reg[0]));
        iodesc.length = be32_to_cpu(reg[1]) - 1;
        iodesc.virtual = (unsigned long)S5P_VA_CHIPID;
        iodesc.type = MT_DEVICE;
        iotable_init(&iodesc, 1);
        return 1;
}

static void __init exynos_init_io(void)
{
        debug_ll_io_init();

        of_scan_flat_dt(exynos_fdt_map_chipid, NULL);

        /* detect cpu id and rev. */
        exynos_cpu_id = readl_relaxed(S5P_VA_CHIPID);
        exynos_cpu_rev = exynos_cpu_id & 0xFF;

        pr_info("Samsung CPU ID: 0x%08lx\n", exynos_cpu_id);

}

/*
 * Set or clear the USE_DELAYED_RESET_ASSERTION option. Used by smp code
 * and suspend.
 *
 * This is necessary only on Exynos4 SoCs. When system is running
 * USE_DELAYED_RESET_ASSERTION should be set so the ARM CLK clock down
 * feature could properly detect global idle state when secondary CPU is
 * powered down.
 *
 * However this should not be set when such system is going into suspend.
 */
void exynos_set_delayed_reset_assertion(bool enable)
{
        if (of_machine_is_compatible("samsung,exynos4")) {
                unsigned int tmp, core_id;

                for (core_id = 0; core_id < num_possible_cpus(); core_id++) {
                        tmp = pmu_raw_readl(EXYNOS_ARM_CORE_OPTION(core_id));
                        if (enable)
                                tmp |= S5P_USE_DELAYED_RESET_ASSERTION;
                        else
                                tmp &= ~(S5P_USE_DELAYED_RESET_ASSERTION);
                        pmu_raw_writel(tmp, EXYNOS_ARM_CORE_OPTION(core_id));
                }
        }
}

/*
 * Apparently, these SoCs are not able to wake-up from suspend using
 * the PMU. Too bad. Should they suddenly become capable of such a
 * feat, the matches below should be moved to suspend.c.
 */
static const struct of_device_id exynos_dt_pmu_match[] = {
        { .compatible = "samsung,exynos5260-pmu" },
        { .compatible = "samsung,exynos5410-pmu" },
        { /*sentinel*/ },
};

static void exynos_map_pmu(void)
{
        struct device_node *np;

        np = of_find_matching_node(NULL, exynos_dt_pmu_match);
        if (np)
                pmu_base_addr = of_iomap(np, 0);
        of_node_put(np);
}

static void __init exynos_init_irq(void)
{
        irqchip_init();
        /*
         * Since platsmp.c needs pmu base address by the time
         * DT is not unflatten so we can't use DT APIs before
         * init_irq
         */
        exynos_map_pmu();
}

static void __init exynos_dt_machine_init(void)
{
        /*
         * This is called from smp_prepare_cpus if we've built for SMP, but
         * we still need to set it up for PM and firmware ops if not.
         */
        if (!IS_ENABLED(CONFIG_SMP))
                exynos_sysram_init();

#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
        if (of_machine_is_compatible("samsung,exynos4210") ||
            of_machine_is_compatible("samsung,exynos3250"))
                exynos_cpuidle.dev.platform_data = &cpuidle_coupled_exynos_data;
#endif
        if (of_machine_is_compatible("samsung,exynos4210") ||
            of_machine_is_compatible("samsung,exynos4212") ||
            (of_machine_is_compatible("samsung,exynos4412") &&
             (of_machine_is_compatible("samsung,trats2") ||
                  of_machine_is_compatible("samsung,midas") ||
                  of_machine_is_compatible("samsung,p4note"))) ||
            of_machine_is_compatible("samsung,exynos3250") ||
            of_machine_is_compatible("samsung,exynos5250"))
                platform_device_register(&exynos_cpuidle);
}

static char const *const exynos_dt_compat[] __initconst = {
        "samsung,exynos3",
        "samsung,exynos3250",
        "samsung,exynos4",
        "samsung,exynos4210",
        "samsung,exynos4212",
        "samsung,exynos4412",
        "samsung,exynos5",
        "samsung,exynos5250",
        "samsung,exynos5260",
        "samsung,exynos5420",
        NULL
};

static void __init exynos_dt_fixup(void)
{
        /*
         * Some versions of uboot pass garbage entries in the memory node,
         * use the old CONFIG_ARM_NR_BANKS
         */
        of_fdt_limit_memory(8);
}

DT_MACHINE_START(EXYNOS_DT, "Samsung Exynos (Flattened Device Tree)")
        .l2c_aux_val    = 0x08400000,
        .l2c_aux_mask   = 0xf60fffff,
        .smp            = smp_ops(exynos_smp_ops),
        .map_io         = exynos_init_io,
        .init_early     = exynos_firmware_init,
        .init_irq       = exynos_init_irq,
        .init_machine   = exynos_dt_machine_init,
        .init_late      = exynos_pm_init,
        .dt_compat      = exynos_dt_compat,
        .dt_fixup       = exynos_dt_fixup,
MACHINE_END