// 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/debug.h>
#include <ddk/protocol/usb.h>
#include <ddk/protocol/usb/bus.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "usb-bus.h"
#include "usb-device.h"

static zx_status_t bus_add_device(void* ctx, uint32_t device_id, uint32_t hub_id,
                                      usb_speed_t speed) {
    usb_bus_t* bus = ctx;

    if (device_id >= bus->max_device_count) return ZX_ERR_INVALID_ARGS;

    // bus->devices[device_id] must be set before usb_device_add() creates the interface devices
    // so we pass pointer to it here rather than setting it after usb_device_add() returns.
    return usb_device_add(bus, device_id, hub_id, speed, &bus->devices[device_id]);
}

static zx_status_t bus_remove_device(void* ctx, uint32_t device_id) {
    usb_bus_t* bus = ctx;
    if (device_id >= bus->max_device_count) {
        zxlogf(ERROR, "device_id out of range in usb_bus_remove_device\n");
        return ZX_ERR_INVALID_ARGS;
    }
    usb_device_t* device = bus->devices[device_id];
    if (!device) {
        return ZX_ERR_BAD_STATE;
    }
    device_remove(device->zxdev);
    bus->devices[device_id] = NULL;
    return ZX_OK;
}

static zx_status_t bus_reset_hub_port(void* ctx, uint32_t hub_id, uint32_t port) {
    usb_bus_t* bus = ctx;
    if (hub_id >= bus->max_device_count) {
        zxlogf(ERROR, "hub_id out of range in usb_bus_reset_hub_port\n");
        return ZX_ERR_INVALID_ARGS;
    }
    usb_device_t* device = bus->devices[hub_id];
    if (!device) {
        zxlogf(ERROR, "hub not found in usb_bus_reset_hub_port\n");
        return ZX_ERR_INVALID_ARGS;
    }
    if (device->hub_intf.ops == NULL) {
        zxlogf(ERROR, "hub interface not set in usb_bus_reset_hub_port\n");
        return ZX_ERR_BAD_STATE;
    }
    return usb_hub_interface_reset_port(&device->hub_intf, port);
}

static usb_bus_interface_ops_t _bus_interface = {
    .add_device = bus_add_device,
    .remove_device = bus_remove_device,
    .reset_port = bus_reset_hub_port,
};

static zx_status_t bus_get_device_id(zx_device_t* device, uint32_t* out) {
    usb_protocol_t usb;
    if (device_get_protocol(device, ZX_PROTOCOL_USB, &usb) != ZX_OK) {
        return ZX_ERR_INTERNAL;
    }
    *out = usb_get_device_id(&usb);
    return ZX_OK;
}

static zx_status_t bus_configure_hub(void* ctx, zx_device_t* hub_device, usb_speed_t speed,
                                     const usb_hub_descriptor_t* desc) {
    usb_bus_t* bus = ctx;
    uint32_t hub_id;
    if (bus_get_device_id(hub_device, &hub_id) != ZX_OK) {
        return ZX_ERR_INTERNAL;
    }
    return usb_hci_configure_hub(&bus->hci, hub_id, speed, desc);
}

static zx_status_t bus_device_added(void* ctx, zx_device_t* hub_device, uint32_t port,
                                    usb_speed_t speed) {
    usb_bus_t* bus = ctx;
    uint32_t hub_id;
    if (bus_get_device_id(hub_device, &hub_id) != ZX_OK) {
        return ZX_ERR_INTERNAL;
    }
    return usb_hci_hub_device_added(&bus->hci, hub_id, port, speed);
}

static zx_status_t bus_device_removed(void* ctx, zx_device_t* hub_device, uint32_t port) {
    usb_bus_t* bus = ctx;
    uint32_t hub_id;
    if (bus_get_device_id(hub_device, &hub_id) != ZX_OK) {
        return ZX_ERR_INTERNAL;
    }
    return usb_hci_hub_device_removed(&bus->hci, hub_id, port);
}

static zx_status_t bus_set_hub_interface(void* ctx, zx_device_t* usb_device,
                                         const usb_hub_interface_t* hub) {
    usb_bus_t* bus = ctx;
    uint32_t usb_device_id;
    if (bus_get_device_id(usb_device, &usb_device_id) != ZX_OK) {
        return ZX_ERR_INTERNAL;
    }
    usb_device_t* usb_dev = bus->devices[usb_device_id];
    if (!usb_dev) {
        zxlogf(ERROR, "bus_set_hub_interface: no device for usb_device_id %u\n", usb_device_id);
        return ZX_ERR_INTERNAL;
    }
    usb_device_set_hub_interface(usb_dev, hub);
    return ZX_OK;
}

static usb_bus_protocol_ops_t _bus_protocol = {
    .configure_hub = bus_configure_hub,
    .device_added = bus_device_added,
    .device_removed = bus_device_removed,
    .set_hub_interface = bus_set_hub_interface,
};

static void usb_bus_unbind(void* ctx) {
    zxlogf(INFO, "usb_bus_unbind\n");
    usb_bus_t* bus = ctx;
    usb_hci_set_bus_interface(&bus->hci, NULL);

    for (size_t i = 0; i < bus->max_device_count; i++) {
        usb_device_t* device = bus->devices[i];
        if (device) {
            device_remove(device->zxdev);
            bus->devices[i] = NULL;
        }
    }
    device_remove(bus->zxdev);
}

static void usb_bus_release(void* ctx) {
    zxlogf(INFO, "usb_bus_release\n");
    usb_bus_t* bus = ctx;
    free(bus->devices);
    free(bus);
}

static zx_protocol_device_t usb_bus_device_proto = {
    .version = DEVICE_OPS_VERSION,
    .unbind = usb_bus_unbind,
    .release = usb_bus_release,
};

static zx_status_t usb_bus_bind(void* ctx, zx_device_t* device) {
    usb_bus_t* bus = calloc(1, sizeof(usb_bus_t));
    if (!bus) {
        zxlogf(ERROR, "Not enough memory for usb_bus_t.\n");
        return ZX_ERR_NO_MEMORY;
    }

    if (device_get_protocol(device, ZX_PROTOCOL_USB_HCI, &bus->hci)) {
        free(bus);
        return ZX_ERR_NOT_SUPPORTED;
    }

    zx_status_t status = usb_hci_get_bti(&bus->hci, &bus->bti_handle);
    if (status != ZX_OK) {
        free(bus);
        return status;
    }

    bus->hci_zxdev = device;
    bus->max_device_count = usb_hci_get_max_device_count(&bus->hci);
    bus->devices = calloc(bus->max_device_count, sizeof(usb_device_t *));
    if (!bus->devices) {
        zxlogf(ERROR, "Not enough memory for usb_bus_t->devices. max_device_count: %zu\n",
               bus->max_device_count);
        free(bus);
        return ZX_ERR_NO_MEMORY;
    }

    device_add_args_t args = {
        .version = DEVICE_ADD_ARGS_VERSION,
        .name = "usb",
        .ctx = bus,
        .ops = &usb_bus_device_proto,
        .proto_id = ZX_PROTOCOL_USB_BUS,
        .proto_ops = &_bus_protocol,
        .flags = DEVICE_ADD_NON_BINDABLE,
    };

    status = device_add(device, &args, &bus->zxdev);
    if (status == ZX_OK) {
        static usb_bus_interface_t bus_intf;
        bus_intf.ops = &_bus_interface;
        bus_intf.ctx = bus;
        usb_hci_set_bus_interface(&bus->hci, &bus_intf);
    } else {
        free(bus->devices);
        free(bus);
    }

    return status;
}

static zx_driver_ops_t usb_bus_driver_ops = {
    .version = DRIVER_OPS_VERSION,
    .bind = usb_bus_bind,
};

ZIRCON_DRIVER_BEGIN(usb_bus, usb_bus_driver_ops, "zircon", "0.1", 1)
    BI_MATCH_IF(EQ, BIND_PROTOCOL, ZX_PROTOCOL_USB_HCI),
ZIRCON_DRIVER_END(usb_bus)