// SPDX-License-Identifier: MIT
/*
 * Copyright © 2026 Intel Corporation
 */

#include <linux/device.h>
#include <linux/mutex.h>

#include <drm/drm_managed.h>

#include "regs/xe_irq_regs.h"
#include "regs/xe_sysctrl_regs.h"
#include "xe_device.h"
#include "xe_mmio.h"
#include "xe_pm.h"
#include "xe_soc_remapper.h"
#include "xe_sysctrl.h"
#include "xe_sysctrl_mailbox.h"
#include "xe_sysctrl_types.h"

/**
 * DOC: System Controller (sysctrl)
 *
 * System Controller (sysctrl) is a firmware-managed entity on Intel dGPUs
 * responsible for selected low-level platform management functions.
 * Communication between driver and System Controller is performed
 * via a mailbox interface, enabling command and response exchange.
 *
 * This module provides initialization and support code for interacting
 * with System Controller through the mailbox interface.
 */
static void sysctrl_fini(void *arg)
{
        struct xe_device *xe = arg;
        struct xe_sysctrl *sc = &xe->sc;

        disable_work_sync(&sc->work);
        xe->soc_remapper.set_sysctrl_region(xe, 0);
}

static void xe_sysctrl_work(struct work_struct *work)
{
        struct xe_sysctrl *sc = container_of(work, struct xe_sysctrl, work);
        struct xe_device *xe = sc_to_xe(sc);

        guard(xe_pm_runtime)(xe);
        xe_sysctrl_event(sc);
}

/**
 * xe_sysctrl_init() - Initialize System Controller subsystem
 * @xe: xe device instance
 *
 * Entry point for System Controller initialization, called from xe_device_probe.
 * This function checks platform support and initializes the system controller.
 *
 * Return: 0 on success, error code on failure
 */
int xe_sysctrl_init(struct xe_device *xe)
{
        struct xe_tile *tile = xe_device_get_root_tile(xe);
        struct xe_sysctrl *sc = &xe->sc;
        int ret;

        if (!xe->info.has_soc_remapper_sysctrl)
                return 0;

        if (!xe->info.has_sysctrl)
                return 0;

        sc->mmio = devm_kzalloc(xe->drm.dev, sizeof(*sc->mmio), GFP_KERNEL);
        if (!sc->mmio)
                return -ENOMEM;

        xe_mmio_init(sc->mmio, tile, tile->mmio.regs, tile->mmio.regs_size);
        sc->mmio->adj_offset = SYSCTRL_BASE;
        sc->mmio->adj_limit = U32_MAX;

        ret = devm_mutex_init(xe->drm.dev, &sc->cmd_lock);
        if (ret)
                return ret;

        ret = devm_mutex_init(xe->drm.dev, &sc->event_lock);
        if (ret)
                return ret;

        xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
        xe_sysctrl_mailbox_init(sc);
        INIT_WORK(&sc->work, xe_sysctrl_work);

        return devm_add_action_or_reset(xe->drm.dev, sysctrl_fini, xe);
}

/**
 * xe_sysctrl_irq_handler() - Handler for System Controller interrupts
 * @xe: xe device instance
 * @master_ctl: interrupt register
 *
 * Handle interrupts generated by System Controller.
 */
void xe_sysctrl_irq_handler(struct xe_device *xe, u32 master_ctl)
{
        struct xe_sysctrl *sc = &xe->sc;

        if (!xe->info.has_sysctrl || !sc->work.func)
                return;

        if (master_ctl & SYSCTRL_IRQ)
                schedule_work(&sc->work);
}

/**
 * xe_sysctrl_pm_resume() - System Controller resume handler
 * @xe: xe device instance
 *
 * Invoked during system resume (S3/S4 to S0) and runtime resume from D3cold.
 * Restores SoC remapper configuration and reinitializes mailbox interface.
 */
void xe_sysctrl_pm_resume(struct xe_device *xe)
{
        struct xe_sysctrl *sc = &xe->sc;

        if (!xe->info.has_soc_remapper_sysctrl)
                return;

        if (!xe->info.has_sysctrl)
                return;

        xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);

        xe_sysctrl_mailbox_init(sc);
}