// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <ddk/binding.h>
#include <ddk/device.h>
#include <ddk/driver.h>
#include <ddk/metadata.h>

#include <zircon/types.h>
#include <zircon/process.h>
#include <zircon/processargs.h>

#include <fuchsia/sysinfo/c/fidl.h>
#include <zircon/boot/image.h>
#include <zircon/syscalls/resource.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <threads.h>


#define ID_HJOBROOT 4

typedef struct {
    zx_device_t* zxdev;
    zx_handle_t job_root;
    mtx_t lock;
    char board_name[ZBI_BOARD_NAME_LEN];
} sysinfo_t;

static zx_handle_t get_sysinfo_job_root(sysinfo_t* sysinfo) {
    mtx_lock(&sysinfo->lock);
    if (sysinfo->job_root == ZX_HANDLE_INVALID) {
        sysinfo->job_root = zx_take_startup_handle(PA_HND(PA_USER0, ID_HJOBROOT));
    }
    mtx_unlock(&sysinfo->lock);

    zx_handle_t h;
    if ((sysinfo->job_root != ZX_HANDLE_INVALID) &&
        (zx_handle_duplicate(sysinfo->job_root, ZX_RIGHT_SAME_RIGHTS, &h) == ZX_OK)) {
        return h;
    }

    return ZX_HANDLE_INVALID;
}

static zx_status_t fidl_get_root_job(void* ctx, fidl_txn_t* txn) {
    sysinfo_t* sysinfo = ctx;

    zx_handle_t h = get_sysinfo_job_root(sysinfo);
    zx_status_t status = h == ZX_HANDLE_INVALID ? ZX_ERR_NOT_SUPPORTED : ZX_OK;

    return fuchsia_sysinfo_DeviceGetRootJob_reply(txn, status, h);
}

static zx_status_t fidl_get_root_resource(void* ctx, fidl_txn_t* txn) {
    zx_handle_t h = get_root_resource();
    if (h == ZX_HANDLE_INVALID) {
        return fuchsia_sysinfo_DeviceGetRootResource_reply(txn, ZX_ERR_NOT_SUPPORTED, h);
    }

    zx_status_t status = zx_handle_duplicate(h, ZX_RIGHT_TRANSFER, &h);
    return fuchsia_sysinfo_DeviceGetRootResource_reply(txn, status, h);
}

static zx_status_t fidl_get_hypervisor_resource(void* ctx, fidl_txn_t* txn) {
    zx_handle_t h;
    const char name[] = "hypervisor";
    zx_status_t status = zx_resource_create(get_root_resource(),
                                            ZX_RSRC_KIND_HYPERVISOR,
                                            0, 0, name, sizeof(name), &h);
    return fuchsia_sysinfo_DeviceGetHypervisorResource_reply(txn, status, h);
}

static zx_status_t fidl_get_board_name(void* ctx, fidl_txn_t* txn) {
    sysinfo_t* sysinfo = ctx;

    zx_status_t status = ZX_OK;

    mtx_lock(&sysinfo->lock);
    if (sysinfo->board_name[0] == 0) {
        size_t actual = 0;
        status = device_get_metadata(sysinfo->zxdev, DEVICE_METADATA_BOARD_NAME,
                                     sysinfo->board_name, sizeof(sysinfo->board_name),
                                     &actual);
    }
    mtx_unlock(&sysinfo->lock);

    size_t board_name_len = strnlen(sysinfo->board_name, sizeof(sysinfo->board_name));
    return fuchsia_sysinfo_DeviceGetBoardName_reply(txn, status, sysinfo->board_name,
                                                    board_name_len);
}

static zx_status_t fidl_get_interrupt_controller_info(void* ctx, fidl_txn_t* txn) {
    zx_status_t status = ZX_OK;
    fuchsia_sysinfo_InterruptControllerInfo info = {};

#if defined(__aarch64__)
    sysinfo_t* sysinfo = ctx;
    size_t actual = 0;
    status = device_get_metadata(sysinfo->zxdev, DEVICE_METADATA_INTERRUPT_CONTROLLER_TYPE,
                                 &info.type, sizeof(uint8_t), &actual);
#elif defined(__x86_64__)
    info.type = fuchsia_sysinfo_InterruptControllerType_APIC;
#else
    info.type = fuchsia_sysinfo_InterruptControllerType_UNKNOWN;
#endif

    return fuchsia_sysinfo_DeviceGetInterruptControllerInfo_reply(txn, status, &info);
}

static fuchsia_sysinfo_Device_ops_t fidl_ops = {
    .GetRootJob = fidl_get_root_job,
    .GetRootResource = fidl_get_root_resource,
    .GetHypervisorResource = fidl_get_hypervisor_resource,
    .GetBoardName = fidl_get_board_name,
    .GetInterruptControllerInfo = fidl_get_interrupt_controller_info,
};

static zx_status_t sysinfo_message(void* ctx, fidl_msg_t* msg, fidl_txn_t* txn) {
    return fuchsia_sysinfo_Device_dispatch(ctx, txn, msg, &fidl_ops);
}

static zx_protocol_device_t sysinfo_ops = {
    .version = DEVICE_OPS_VERSION,
    .message = sysinfo_message,
};

zx_status_t sysinfo_bind(void* ctx, zx_device_t* parent) {
    sysinfo_t* sysinfo = calloc(1, sizeof(sysinfo_t));
    if (!sysinfo) {
        return ZX_ERR_NO_MEMORY;
    }

    mtx_init(&sysinfo->lock, mtx_plain);

    device_add_args_t args = {
        .version = DEVICE_ADD_ARGS_VERSION,
        .name = "sysinfo",
        .ctx = sysinfo,
        .ops = &sysinfo_ops,
    };

    return device_add(parent, &args, &sysinfo->zxdev);
}

static zx_driver_ops_t sysinfo_driver_ops = {
    .version = DRIVER_OPS_VERSION,
    .bind = sysinfo_bind,
};

ZIRCON_DRIVER_BEGIN(sysinfo, sysinfo_driver_ops, "zircon", "0.1", 1)
    BI_MATCH_IF(EQ, BIND_PROTOCOL, ZX_PROTOCOL_MISC_PARENT),
ZIRCON_DRIVER_END(sysinfo)