// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
 *
 * Based on drivers/firmware/psci.c from Linux:
 * Copyright (C) 2015 ARM Limited
 */

#include <common.h>
#include <command.h>
#include <dm.h>
#include <irq_func.h>
#include <log.h>
#include <dm/lists.h>
#include <efi_loader.h>
#include <sysreset.h>
#include <linux/delay.h>
#include <linux/libfdt.h>
#include <linux/arm-smccc.h>
#include <linux/errno.h>
#include <linux/printk.h>
#include <linux/psci.h>
#include <asm/system.h>

#define DRIVER_NAME "psci"

#define PSCI_METHOD_HVC 1
#define PSCI_METHOD_SMC 2

/*
 * While a 64-bit OS can make calls with SMC32 calling conventions, for some
 * calls it is necessary to use SMC64 to pass or return 64-bit values.
 * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
 * (native-width) function ID.
 */
#if defined(CONFIG_ARM64)
#define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN64_##name
#else
#define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN_##name
#endif

#if CONFIG_IS_ENABLED(EFI_LOADER)
int __efi_runtime_data psci_method;
#else
int psci_method __section(".data");
#endif

unsigned long __efi_runtime invoke_psci_fn
                (unsigned long function_id, unsigned long arg0,
                 unsigned long arg1, unsigned long arg2)
{
        struct arm_smccc_res res;

        /*
         * In the __efi_runtime we need to avoid the switch statement. In some
         * cases the compiler creates lookup tables to implement switch. These
         * tables are not correctly relocated when SetVirtualAddressMap is
         * called.
         */
        if (psci_method == PSCI_METHOD_SMC)
                arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
        else if (psci_method == PSCI_METHOD_HVC)
                arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
        else
                res.a0 = PSCI_RET_DISABLED;
        return res.a0;
}

static int request_psci_features(u32 psci_func_id)
{
        return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
                              psci_func_id, 0, 0);
}

static u32 psci_0_2_get_version(void)
{
        return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
}

static bool psci_is_system_reset2_supported(void)
{
        int ret;
        u32 ver;

        ver = psci_0_2_get_version();

        if (PSCI_VERSION_MAJOR(ver) >= 1) {
                ret = request_psci_features(PSCI_FN_NATIVE(1_1,
                                                           SYSTEM_RESET2));

                if (ret != PSCI_RET_NOT_SUPPORTED)
                        return true;
        }

        return false;
}

static int psci_bind(struct udevice *dev)
{
        /* No SYSTEM_RESET support for PSCI 0.1 */
        if (device_is_compatible(dev, "arm,psci-0.2") ||
            device_is_compatible(dev, "arm,psci-1.0")) {
                int ret;

                /* bind psci-sysreset optionally */
                ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
                                         NULL);
                if (ret)
                        pr_debug("PSCI System Reset was not bound.\n");
        }

        return 0;
}

static int psci_probe(struct udevice *dev)
{
        const char *method;

#if defined(CONFIG_ARM64)
        if (current_el() == 3)
                return -EINVAL;
#endif

        method = ofnode_read_string(dev_ofnode(dev), "method");
        if (!method) {
                pr_warn("missing \"method\" property\n");
                return -ENXIO;
        }

        if (!strcmp("hvc", method)) {
                psci_method = PSCI_METHOD_HVC;
        } else if (!strcmp("smc", method)) {
                psci_method = PSCI_METHOD_SMC;
        } else {
                pr_warn("invalid \"method\" property: %s\n", method);
                return -EINVAL;
        }

        return 0;
}

/**
 * void do_psci_probe() - probe PSCI firmware driver
 *
 * Ensure that psci_method is initialized.
 */
static void __maybe_unused do_psci_probe(void)
{
        struct udevice *dev;

        uclass_get_device_by_name(UCLASS_FIRMWARE, DRIVER_NAME, &dev);
}

#if IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET)
efi_status_t efi_reset_system_init(void)
{
        do_psci_probe();
        return EFI_SUCCESS;
}

void __efi_runtime EFIAPI efi_reset_system(enum efi_reset_type reset_type,
                                           efi_status_t reset_status,
                                           unsigned long data_size,
                                           void *reset_data)
{
        if (reset_type == EFI_RESET_COLD ||
            reset_type == EFI_RESET_WARM ||
            reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
                invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
        } else if (reset_type == EFI_RESET_SHUTDOWN) {
                invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
        }
        while (1)
                ;
}
#endif /* IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET) */

#ifdef CONFIG_PSCI_RESET
void reset_misc(void)
{
        do_psci_probe();
        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
}
#endif /* CONFIG_PSCI_RESET */

void psci_sys_reset(u32 type)
{
        bool reset2_supported;

        do_psci_probe();

        reset2_supported = psci_is_system_reset2_supported();

        if (type == SYSRESET_WARM && reset2_supported) {
                /*
                 * reset_type[31] = 0 (architectural)
                 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
                 * cookie = 0 (ignored by the implementation)
                 */
                invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
        } else {
                invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
        }
}

void psci_sys_poweroff(void)
{
        do_psci_probe();

        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
}

#if IS_ENABLED(CONFIG_CMD_POWEROFF) && !IS_ENABLED(CONFIG_SYSRESET_CMD_POWEROFF)
int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        do_psci_probe();

        puts("poweroff ...\n");
        udelay(50000); /* wait 50 ms */

        disable_interrupts();
        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
        enable_interrupts();

        log_err("Power off not supported on this platform\n");
        return CMD_RET_FAILURE;
}
#endif

static const struct udevice_id psci_of_match[] = {
        { .compatible = "arm,psci" },
        { .compatible = "arm,psci-0.2" },
        { .compatible = "arm,psci-1.0" },
        {},
};

U_BOOT_DRIVER(psci) = {
        .name = DRIVER_NAME,
        .id = UCLASS_FIRMWARE,
        .of_match = psci_of_match,
        .bind = psci_bind,
        .probe = psci_probe,
};