// Copyright 2017 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/protocol/pciroot.h>

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/stat.h>

#include <zircon/compiler.h>
#include <zircon/process.h>
#include <zircon/processargs.h>
#include <zircon/syscalls.h>
#include <fdio/debug.h>

#include "init.h"
#include "dev.h"
#include "pci.h"
#include "powerbtn.h"
#include "processor.h"
#include "power.h"

#define MXDEBUG 0

#define MAX_NAMESPACE_DEPTH 100

#define HID_LENGTH 8

typedef struct acpi_device {
    zx_device_t* mxdev;

    // handle to the corresponding ACPI node
    ACPI_HANDLE ns_node;
} acpi_device_t;

zx_handle_t root_resource_handle;
zx_handle_t rpc_handle;

static int acpi_rpc_thread(void* arg) {
    xprintf("bus-acpi: rpc thread starting\n");
    zx_status_t status = begin_processing(rpc_handle);
    xprintf("bus-acpi: rpc thread returned %d\n", status);
    return (status == ZX_OK) ? 0 : -1;
}

static void acpi_device_release(void* ctx) {
    acpi_device_t* dev = (acpi_device_t*)ctx;
    free(dev);
}

static zx_protocol_device_t acpi_device_proto = {
    .version = DEVICE_OPS_VERSION,
    .release = acpi_device_release,
};

static pciroot_protocol_ops_t pciroot_proto = {
};

static const char* hid_from_acpi_devinfo(ACPI_DEVICE_INFO* info) {
    const char* hid = NULL;
    if ((info->Valid & ACPI_VALID_HID) &&
            (info->HardwareId.Length > 0) &&
            ((info->HardwareId.Length - 1) <= sizeof(uint64_t))) {
        hid = (const char*)info->HardwareId.String;
    }
    return hid;
}

static zx_device_t* publish_device(zx_device_t* parent,
                                   ACPI_HANDLE handle,
                                   ACPI_DEVICE_INFO* info,
                                   uint32_t protocol_id,
                                   void* protocol_ops) {
#if MXDEBUG
    if (!parent) {
        xprintf("acpi-bus: parent is NULL\n");
        return NULL;
    }
#endif
    // ACPI names are always 4 characters in a uint32
    char name[5] = { 0 };
    memcpy(name, &info->Name, sizeof(name) - 1);

    zx_device_prop_t props[4];
    int propcount = 0;

    // Publish HID in device props
    const char* hid = hid_from_acpi_devinfo(info);
    if (hid) {
        props[propcount].id = BIND_ACPI_HID_0_3;
        props[propcount++].value = htobe32(*((uint32_t*)(hid)));
        props[propcount].id = BIND_ACPI_HID_4_7;
        props[propcount++].value = htobe32(*((uint32_t*)(hid + 4)));
    }

    // Publish the first CID in device props
    const char* cid = (const char*)info->CompatibleIdList.Ids[0].String;
    if ((info->Valid & ACPI_VALID_CID) &&
            (info->CompatibleIdList.Count > 0) &&
            ((info->CompatibleIdList.Ids[0].Length - 1) <= sizeof(uint64_t))) {
        props[propcount].id = BIND_ACPI_CID_0_3;
        props[propcount++].value = htobe32(*((uint32_t*)(cid)));
        props[propcount].id = BIND_ACPI_CID_4_7;
        props[propcount++].value = htobe32(*((uint32_t*)(cid + 4)));
    }

#if MXDEBUG
    printf("acpi-bus: got device %s\n", name);
    if (info->Valid & ACPI_VALID_HID) {
        printf("     HID=%s\n", info->HardwareId.String);
    } else {
        printf("     HID=invalid\n");
    }
    if (info->Valid & ACPI_VALID_ADR) {
        printf("     ADR=0x%" PRIx64 "\n", (uint64_t)info->Address);
    } else {
        printf("     ADR=invalid\n");
    }
    if (info->Valid & ACPI_VALID_CID) {
        printf("    CIDS=%d\n", info->CompatibleIdList.Count);
        for (uint i = 0; i < info->CompatibleIdList.Count; i++) {
            printf("     [%u] %s\n", i, info->CompatibleIdList.Ids[i].String);
        }
    } else {
        printf("     CID=invalid\n");
    }
    printf("    devprops:\n");
    for (int i = 0; i < propcount; i++) {
        printf("     [%d] id=0x%08x value=0x%08x\n", i, props[i].id, props[i].value);
    }
#endif

    // TODO: publish pciroot and other acpi devices in separate devhosts?

    acpi_device_t* dev = calloc(1, sizeof(acpi_device_t));
    if (!dev) {
        return NULL;
    }

    dev->ns_node = handle;

    device_add_args_t args = {
        .version = DEVICE_ADD_ARGS_VERSION,
        .name = name,
        .ctx = dev,
        .ops = &acpi_device_proto,
        .proto_id = protocol_id,
        .proto_ops = protocol_ops,
        .props = (propcount > 0) ? props : NULL,
        .prop_count = propcount,
    };

    zx_status_t status;
    if ((status = device_add(parent, &args, &dev->mxdev)) != ZX_OK) {
        xprintf("acpi-bus: error %d in device_add, parent=%s(%p)\n", status, device_get_name(parent), parent);
        free(dev);
        return NULL;
    } else {
        xprintf("acpi-bus: published device %s(%p), parent=%s(%p), handle=%p\n",
                name, dev, device_get_name(parent), parent, (void*)dev->ns_node);
        return dev->mxdev;
    }
}

static ACPI_STATUS acpi_ns_walk_callback(ACPI_HANDLE object, uint32_t nesting_level,
                                         void* context, void** status) {
    ACPI_DEVICE_INFO* info = NULL;
    ACPI_STATUS acpi_status = AcpiGetObjectInfo(object, &info);
    if (acpi_status != AE_OK) {
        return acpi_status;
    }

    // TODO: This is a temporary workaround until we have full ACPI device
    // enumeration. If this is the I2C1 bus, we run _PS0 so the controller
    // is active.
    if (!memcmp(&info->Name, "I2C1", 4)) {
        ACPI_STATUS acpi_status = AcpiEvaluateObject(object, (char*)"_PS0", NULL, NULL);
        if (acpi_status != AE_OK) {
            printf("acpi-bus: acpi error 0x%x in I2C1._PS0\n", acpi_status);
        }
    }

    xprintf("acpi-bus: handle %p nesting level %d\n", (void*)object, nesting_level);

    // Only publish PCIE/PCI roots
    zx_device_t* parent = (zx_device_t*)context;
    const char* hid = hid_from_acpi_devinfo(info);
    if (hid == 0) {
        goto out;
    }
    if (!memcmp(hid, PCI_EXPRESS_ROOT_HID_STRING, HID_LENGTH) ||
                !memcmp(hid, PCI_ROOT_HID_STRING, HID_LENGTH)) {
        publish_device(parent, object, info, ZX_PROTOCOL_PCIROOT, &pciroot_proto);
    } else if (!memcmp(hid, BATTERY_HID_STRING, HID_LENGTH)) {
        battery_init(parent, object);
    } else if (!memcmp(hid, PWRSRC_HID_STRING, HID_LENGTH)) {
        pwrsrc_init(parent, object);
    } else if (!memcmp(hid, EC_HID_STRING, HID_LENGTH)) {
        ec_init(parent, object);
    }

out:
    ACPI_FREE(info);

    return AE_OK;
}

static zx_status_t publish_pci_roots(zx_device_t* parent) {
    // Walk the ACPI namespace for devices and publish them
    ACPI_STATUS acpi_status = AcpiWalkNamespace(ACPI_TYPE_DEVICE,
                                                ACPI_ROOT_OBJECT,
                                                MAX_NAMESPACE_DEPTH,
                                                acpi_ns_walk_callback,
                                                NULL, parent, NULL);
    if (acpi_status != AE_OK) {
        return ZX_ERR_BAD_STATE;
    } else {
        return ZX_OK;
    }
}

static zx_status_t acpi_drv_bind(void* ctx, zx_device_t* parent, void** cookie) {
    // ACPI is the root driver for its devhost so run init in the bind thread.
    xprintf("bus-acpi: bind to %s %p\n", device_get_name(parent), parent);
    root_resource_handle = get_root_resource();

    // Get RPC channel
    rpc_handle = zx_get_startup_handle(PA_HND(PA_USER0, 10));
    if (rpc_handle == ZX_HANDLE_INVALID) {
        xprintf("bus-acpi: no acpi rpc handle\n");
        return ZX_ERR_INVALID_ARGS;
    }

    if (init() != ZX_OK) {
        xprintf("bus_acpi: failed to initialize ACPI\n");
        return ZX_ERR_INTERNAL;
    }

    printf("acpi-bus: initialized\n");

    zx_status_t status = install_powerbtn_handlers();
    if (status != ZX_OK) {
        xprintf("acpi-bus: error %d in install_powerbtn_handlers\n", status);
        return status;
    }

    // Report current resources to kernel PCI driver
    status = pci_report_current_resources(get_root_resource());
    if (status != ZX_OK) {
        xprintf("acpi-bus: WARNING: ACPI failed to report all current resources!\n");
    }

    // Initialize kernel PCI driver
    zx_pci_init_arg_t* arg;
    uint32_t arg_size;
    status = get_pci_init_arg(&arg, &arg_size);
    if (status != ZX_OK) {
        xprintf("acpi-bus: erorr %d in get_pci_init_arg\n", status);
        return status;
    }

    status = zx_pci_init(get_root_resource(), arg, arg_size);
    if (status != ZX_OK) {
        xprintf("acpi-bus: error %d in zx_pci_init\n", status);
        return status;
    }

    free(arg);

    // start rpc thread
    // TODO: probably will be replaced with devmgr rpc mechanism
    thrd_t rpc_thrd;
    int rc = thrd_create_with_name(&rpc_thrd, acpi_rpc_thread, NULL, "acpi-rpc");
    if (rc != thrd_success) {
        xprintf("acpi-bus: error %d in rpc thrd_create\n", rc);
        return ZX_ERR_INTERNAL;
    }

    // only publish the pci root. ACPI devices are managed by this driver.
    publish_pci_roots(parent);

    return ZX_OK;
}

static zx_driver_ops_t acpi_driver_ops = {
    .version = DRIVER_OPS_VERSION,
    .bind = acpi_drv_bind,
};

ZIRCON_DRIVER_BEGIN(acpi, acpi_driver_ops, "zircon", "0.1", 1)
    BI_MATCH_IF(EQ, BIND_PROTOCOL, ZX_PROTOCOL_ACPI_BUS),
ZIRCON_DRIVER_END(acpi)