// 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/iotxn.h>
#include <ddk/protocol/usb.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "xhci.h"
#include "xhci-device-manager.h"

#define MANUFACTURER_STRING 1
#define PRODUCT_STRING_2    2
#define PRODUCT_STRING_3    3

static const uint8_t xhci_language_list[] =
    { 4, /* bLength */ USB_DT_STRING, 0x09, 0x04, /* language ID */ };
static const uint8_t xhci_manufacturer_string [] = // "Zircon"
    { 18, /* bLength */ USB_DT_STRING, 'M', 0, 'a', 0, 'g', 0, 'e', 0, 'n', 0, 't', 0, 'a', 0, 0, 0 };
static const uint8_t xhci_product_string_2 [] = // "USB 2.0 Root Hub"
    { 36, /* bLength */ USB_DT_STRING, 'U', 0, 'S', 0, 'B', 0, ' ', 0, '2', 0, '.', 0, '0', 0,' ', 0,
                        'R', 0, 'o', 0, 'o', 0, 't', 0, ' ', 0, 'H', 0, 'u', 0, 'b', 0, 0, 0, };
static const uint8_t xhci_product_string_3 [] = // "USB 3.0 Root Hub"
    { 36, /* bLength */ USB_DT_STRING, 'U', 0, 'S', 0, 'B', 0, ' ', 0, '3', 0, '.', 0, '0', 0,' ', 0,
                        'R', 0, 'o', 0, 'o', 0, 't', 0, ' ', 0, 'H', 0, 'u', 0, 'b', 0, 0, 0, };

static const uint8_t* xhci_rh_string_table[] = {
    xhci_language_list,
    xhci_manufacturer_string,
    xhci_product_string_2,
    xhci_product_string_3,
};

// device descriptor for USB 2.0 root hub
static const usb_device_descriptor_t xhci_rh_device_desc_2 = {
    .bLength = sizeof(usb_device_descriptor_t),
    .bDescriptorType = USB_DT_DEVICE,
    .bcdUSB = htole16(0x0200),
    .bDeviceClass = USB_CLASS_HUB,
    .bDeviceSubClass = 0,
    .bDeviceProtocol = 1,   // Single TT
    .bMaxPacketSize0 = 64,
    .idVendor = htole16(0x18D1),
    .idProduct = htole16(0xA002),
    .bcdDevice = htole16(0x0100),
    .iManufacturer = MANUFACTURER_STRING,
    .iProduct = PRODUCT_STRING_2,
    .iSerialNumber = 0,
    .bNumConfigurations = 1,
};

// device descriptor for USB 3.1 root hub
static const usb_device_descriptor_t xhci_rh_device_desc_3 = {
    .bLength = sizeof(usb_device_descriptor_t),
    .bDescriptorType = USB_DT_DEVICE,
    .bcdUSB = htole16(0x0300),
    .bDeviceClass = USB_CLASS_HUB,
    .bDeviceSubClass = 0,
    .bDeviceProtocol = 1,   // Single TT
    .bMaxPacketSize0 = 64,
    .idVendor = htole16(0x18D1),
    .idProduct = htole16(0xA003),
    .bcdDevice = htole16(0x0100),
    .iManufacturer = MANUFACTURER_STRING,
    .iProduct = PRODUCT_STRING_3,
    .iSerialNumber = 0,
    .bNumConfigurations = 1,
};

// device descriptors for our virtual root hub devices
static const usb_device_descriptor_t* xhci_rh_device_descs[] = {
    (usb_device_descriptor_t *)&xhci_rh_device_desc_2,
    (usb_device_descriptor_t *)&xhci_rh_device_desc_3,
};

// we are currently using the same configuration descriptors for both USB 2.0 and 3.0 root hubs
// this is not actually correct, but our usb-hub driver isn't sophisticated enough to notice
static const struct {
    usb_configuration_descriptor_t config;
    usb_interface_descriptor_t intf;
    usb_endpoint_descriptor_t endp;
} xhci_rh_config_desc = {
     .config = {
        .bLength = sizeof(usb_configuration_descriptor_t),
        .bDescriptorType = USB_DT_CONFIG,
        .wTotalLength = htole16(sizeof(xhci_rh_config_desc)),
        .bNumInterfaces = 1,
        .bConfigurationValue = 1,
        .iConfiguration = 0,
        .bmAttributes = 0xE0,   // self powered
        .bMaxPower = 0,
    },
    .intf = {
        .bLength = sizeof(usb_interface_descriptor_t),
        .bDescriptorType = USB_DT_INTERFACE,
        .bInterfaceNumber = 0,
        .bAlternateSetting = 0,
        .bNumEndpoints = 1,
        .bInterfaceClass = USB_CLASS_HUB,
        .bInterfaceSubClass = 0,
        .bInterfaceProtocol = 0,
        .iInterface = 0,
    },
    .endp = {
        .bLength = sizeof(usb_endpoint_descriptor_t),
        .bDescriptorType = USB_DT_ENDPOINT,
        .bEndpointAddress = USB_ENDPOINT_IN | 1,
        .bmAttributes = USB_ENDPOINT_INTERRUPT,
        .wMaxPacketSize = htole16(4),
        .bInterval = 12,
    },
};

// speeds for our virtual root hub devices
static const usb_speed_t xhci_rh_speeds[] = {
    USB_SPEED_HIGH,
    USB_SPEED_SUPER,
};

static void print_portsc(int port, uint32_t portsc) {
    dprintf(SPEW, "port %d:", port);
    if (portsc & PORTSC_CCS) dprintf(SPEW, " CCS");
    if (portsc & PORTSC_PED) dprintf(SPEW, " PED");
    if (portsc & PORTSC_OCA) dprintf(SPEW, " OCA");
    if (portsc & PORTSC_PR) dprintf(SPEW, " PR");
    uint32_t pls = (portsc >> PORTSC_PLS_START) & ((1 << PORTSC_PLS_BITS) - 1);
    switch (pls) {
        case 0:
            dprintf(SPEW, " U0");
            break;
        case 1:
            dprintf(SPEW, " U1");
            break;
        case 2:
            dprintf(SPEW, " U2");
            break;
        case 3:
            dprintf(SPEW, " U3");
            break;
        case 4:
            dprintf(SPEW, " Disabled");
            break;
        case 5:
            dprintf(SPEW, " RxDetect");
            break;
        case 6:
            dprintf(SPEW, " Inactive");
            break;
        case 7:
            dprintf(SPEW, " Polling");
            break;
        case 8:
            dprintf(SPEW, " Recovery");
            break;
        case 9:
            dprintf(SPEW, " Hot Reset");
            break;
        case 10:
            dprintf(SPEW, " Compliance Mode");
            break;
        case 11:
            dprintf(SPEW, " Test Mode");
            break;
        case 15:
            dprintf(SPEW, " Resume");
            break;
        default:
            dprintf(SPEW, " PLS%d", pls);
            break;
    }
    if (portsc & PORTSC_PP) dprintf(SPEW, " PP");
    uint32_t speed = (portsc >> PORTSC_SPEED_START) & ((1 << PORTSC_SPEED_BITS) - 1);
    switch (speed) {
        case 1:
            dprintf(SPEW, " FULL_SPEED");
            break;
        case 2:
            dprintf(SPEW, " LOW_SPEED");
            break;
        case 3:
            dprintf(SPEW, " HIGH_SPEED");
            break;
        case 4:
            dprintf(SPEW, " SUPER_SPEED");
            break;
    }
    uint32_t pic = (portsc >> PORTSC_PIC_START) & ((1 << PORTSC_PIC_BITS) - 1);
    dprintf(SPEW, " PIC%d", pic);
    if (portsc & PORTSC_LWS) dprintf(SPEW, " LWS");
    if (portsc & PORTSC_CSC) dprintf(SPEW, " CSC");
    if (portsc & PORTSC_PEC) dprintf(SPEW, " PEC");
    if (portsc & PORTSC_WRC) dprintf(SPEW, " WRC");
    if (portsc & PORTSC_OCC) dprintf(SPEW, " OCC");
    if (portsc & PORTSC_PRC) dprintf(SPEW, " PRC");
    if (portsc & PORTSC_PLC) dprintf(SPEW, " PLC");
    if (portsc & PORTSC_CEC) dprintf(SPEW, " CEC");
    if (portsc & PORTSC_CAS) dprintf(SPEW, " CAS");
    if (portsc & PORTSC_WCE) dprintf(SPEW, " WCE");
    if (portsc & PORTSC_WDE) dprintf(SPEW, " WDE");
    if (portsc & PORTSC_WOE) dprintf(SPEW, " WOE");
    if (portsc & PORTSC_DR) dprintf(SPEW, " DR");
    if (portsc & PORTSC_WPR) dprintf(SPEW, " WPR");
    dprintf(SPEW, "\n");
}

static void xhci_reset_port(xhci_t* xhci, xhci_root_hub_t* rh, int rh_port_index) {
    volatile uint32_t* portsc = &xhci->op_regs->port_regs[rh_port_index].portsc;
    uint32_t temp = XHCI_READ32(portsc);
    temp = (temp & PORTSC_CONTROL_BITS) | PORTSC_PR;
    if (rh->speed == USB_SPEED_SUPER) {
        temp |= PORTSC_WPR;
    }
    XHCI_WRITE32(portsc, temp);

    int port_index = xhci->rh_port_map[rh_port_index];
    usb_port_status_t* status = &rh->port_status[port_index];
    status->wPortStatus |= USB_PORT_RESET;
    status->wPortChange |= USB_C_PORT_RESET;
}

zx_status_t xhci_root_hub_init(xhci_t* xhci, int rh_index) {
    xhci_root_hub_t* rh = &xhci->root_hubs[rh_index];
    const uint8_t* rh_port_map = xhci->rh_map;
    size_t rh_ports = xhci->rh_num_ports;

    list_initialize(&rh->pending_intr_reqs);

    rh->device_desc = xhci_rh_device_descs[rh_index];
    rh->config_desc = (usb_configuration_descriptor_t *)&xhci_rh_config_desc;

    // first count number of ports
    int port_count = 0;
    for (size_t i = 0; i < rh_ports; i++) {
        if (rh_port_map[i] == rh_index) {
            port_count++;
        }
    }
    rh->num_ports = port_count;

    rh->port_status = (usb_port_status_t *)calloc(port_count, sizeof(usb_port_status_t));
    if (!rh->port_status) return ZX_ERR_NO_MEMORY;

    rh->port_map = calloc(port_count, sizeof(uint8_t));
    if (!rh->port_map) return ZX_ERR_NO_MEMORY;

    // build map from virtual port index to actual port index
    int port_index = 0;
    for (size_t i = 0; i < rh_ports; i++) {
        if (rh_port_map[i] == rh_index) {
            xhci->rh_port_map[i] = port_index;
            rh->port_map[port_index] = i;
            port_index++;
        }
    }

    return ZX_OK;
}

void xhci_root_hub_free(xhci_root_hub_t* rh) {
    free(rh->port_map);
    free(rh->port_status);
}

static zx_status_t xhci_start_root_hub(xhci_t* xhci, xhci_root_hub_t* rh, int rh_index) {
    usb_device_descriptor_t* device_desc = malloc(sizeof(usb_device_descriptor_t));
    if (!device_desc) {
        return ZX_ERR_NO_MEMORY;
    }
    usb_configuration_descriptor_t* config_desc =
                        (usb_configuration_descriptor_t *)malloc(sizeof(xhci_rh_config_desc));
    if (!config_desc) {
        free(device_desc);
        return ZX_ERR_NO_MEMORY;
    }

    memcpy(device_desc, rh->device_desc, sizeof(usb_device_descriptor_t));
    memcpy(config_desc, rh->config_desc, le16toh(rh->config_desc->wTotalLength));
    rh->speed = xhci_rh_speeds[rh_index];

    // Notify bus driver that our emulated hub exists
    return xhci_add_device(xhci, xhci->max_slots + rh_index + 1, 0, rh->speed);
}

zx_status_t xhci_start_root_hubs(xhci_t* xhci) {
    dprintf(TRACE, "xhci_start_root_hubs\n");

    for (int i = 0; i < XHCI_RH_COUNT; i++) {
        zx_status_t status = xhci_start_root_hub(xhci, &xhci->root_hubs[i], i);
        if (status != ZX_OK) {
            dprintf(ERROR, "xhci_start_root_hub(%d) failed: %d\n", i, status);
            return status;
        }
    }

    return ZX_OK;
}

static zx_status_t xhci_rh_get_descriptor(uint8_t request_type, xhci_root_hub_t* rh, uint16_t value,
                                          uint16_t index, size_t length, iotxn_t* txn) {
    uint8_t type = request_type & USB_TYPE_MASK;
    uint8_t recipient = request_type & USB_RECIP_MASK;

    if (type == USB_TYPE_STANDARD && recipient == USB_RECIP_DEVICE) {
        uint8_t desc_type = value >> 8;
        if (desc_type == USB_DT_DEVICE && index == 0) {
            if (length > sizeof(usb_device_descriptor_t)) length = sizeof(usb_device_descriptor_t);
            iotxn_copyto(txn, rh->device_desc, length, 0);
            iotxn_complete(txn, ZX_OK, length);
            return ZX_OK;
        } else if (desc_type == USB_DT_CONFIG && index == 0) {
            uint16_t desc_length = le16toh(rh->config_desc->wTotalLength);
            if (length > desc_length) length = desc_length;
            iotxn_copyto(txn, rh->config_desc, length, 0);
            iotxn_complete(txn, ZX_OK, length);
            return ZX_OK;
        } else if (value >> 8 == USB_DT_STRING) {
            uint8_t string_index = value & 0xFF;
            if (string_index < countof(xhci_rh_string_table)) {
                const uint8_t* string = xhci_rh_string_table[string_index];
                if (length > string[0]) length = string[0];

                iotxn_copyto(txn, string, length, 0);
                iotxn_complete(txn, ZX_OK, length);
                return ZX_OK;
            }
        }
    }
    else if (type == USB_TYPE_CLASS && recipient == USB_RECIP_DEVICE) {
        if ((value == USB_HUB_DESC_TYPE_SS << 8 || value == USB_HUB_DESC_TYPE << 8) && index == 0) {
            // return hub descriptor
            usb_hub_descriptor_t desc;
            memset(&desc, 0, sizeof(desc));
            desc.bDescLength = sizeof(desc);
            desc.bDescriptorType = value >> 8;
            desc.bNbrPorts = rh->num_ports;
            desc.bPowerOn2PwrGood = 0;
            // TODO - fill in other stuff. But usb-hub driver doesn't need anything else at this point.

            if (length > sizeof(desc)) length = sizeof(desc);
            iotxn_copyto(txn, &desc, length, 0);
            iotxn_complete(txn, ZX_OK, length);
            return ZX_OK;
        }
    }

    dprintf(ERROR, "xhci_rh_get_descriptor unsupported value: %d index: %d\n", value, index);
    iotxn_complete(txn, ZX_ERR_NOT_SUPPORTED, 0);
    return ZX_ERR_NOT_SUPPORTED;
}

// handles control requests for virtual root hub devices
static zx_status_t xhci_rh_control(xhci_t* xhci, xhci_root_hub_t* rh, usb_setup_t* setup, iotxn_t* txn) {
    uint8_t request_type = setup->bmRequestType;
    uint8_t request = setup->bRequest;
    uint16_t value = le16toh(setup->wValue);
    uint16_t index = le16toh(setup->wIndex);

    dprintf(TRACE, "xhci_rh_control type: 0x%02X req: %d value: %d index: %d length: %d\n",
            request_type, request, value, index, le16toh(setup->wLength));

    if ((request_type & USB_DIR_MASK) == USB_DIR_IN && request == USB_REQ_GET_DESCRIPTOR) {
        return xhci_rh_get_descriptor(request_type, rh, value, index, le16toh(setup->wLength), txn);
    } else if ((request_type & ~USB_DIR_MASK) == (USB_TYPE_CLASS | USB_RECIP_PORT)) {
        // index is 1-based port number
        if (index < 1 || index > rh->num_ports) {
            iotxn_complete(txn, ZX_ERR_INVALID_ARGS, 0);
            return ZX_OK;
        }
        int rh_port_index = rh->port_map[index - 1];
        int port_index = index - 1;

        if (request == USB_REQ_SET_FEATURE) {
            if (value == USB_FEATURE_PORT_POWER) {
                // nothing to do - root hub ports are already powered
                iotxn_complete(txn, ZX_OK, 0);
                return ZX_OK;
            } else if (value == USB_FEATURE_PORT_RESET) {
                xhci_reset_port(xhci, rh, rh_port_index);
                iotxn_complete(txn, ZX_OK, 0);
                return ZX_OK;
            }
        } else if (request == USB_REQ_CLEAR_FEATURE) {
            uint16_t* change_bits = &rh->port_status[port_index].wPortChange;

            switch (value) {
                case USB_FEATURE_C_PORT_CONNECTION:
                    *change_bits &= ~USB_C_PORT_CONNECTION;
                    break;
                case USB_FEATURE_C_PORT_ENABLE:
                    *change_bits &= ~USB_C_PORT_ENABLE;
                    break;
                case USB_FEATURE_C_PORT_SUSPEND:
                    *change_bits &= ~USB_C_PORT_SUSPEND;
                    break;
                case USB_FEATURE_C_PORT_OVER_CURRENT:
                    *change_bits &= ~USB_C_PORT_OVER_CURRENT;
                    break;
                case USB_FEATURE_C_PORT_RESET:
                    *change_bits &= ~USB_C_PORT_RESET;
                    break;
            }

            iotxn_complete(txn, ZX_OK, 0);
            return ZX_OK;
        } else if ((request_type & USB_DIR_MASK) == USB_DIR_IN &&
                   request == USB_REQ_GET_STATUS && value == 0) {
            usb_port_status_t* status = &rh->port_status[port_index];
            size_t length = txn->length;
            if (length > sizeof(*status)) length = sizeof(*status);
            iotxn_copyto(txn, status, length, 0);
            iotxn_complete(txn, ZX_OK, length);
            return ZX_OK;
        }
    } else if (request_type == (USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE) &&
               request == USB_REQ_SET_CONFIGURATION && txn->length == 0) {
        // nothing to do here
        iotxn_complete(txn, ZX_OK, 0);
        return ZX_OK;
    }

    dprintf(ERROR, "unsupported root hub control request type: 0x%02X req: %d value: %d index: %d\n",
           request_type, request, value, index);

    iotxn_complete(txn, ZX_ERR_NOT_SUPPORTED, 0);
    return ZX_ERR_NOT_SUPPORTED;
}

static void xhci_rh_handle_intr_req(xhci_root_hub_t* rh, iotxn_t* txn) {
    dprintf(TRACE, "xhci_rh_handle_intr_req\n");
    uint8_t status_bits[128 / 8];
    bool have_status = 0;
    uint8_t* ptr = status_bits;
    int bit = 1;    // 0 is for hub status, so start at bit 1

    memset(status_bits, 0, sizeof(status_bits));

    for (uint32_t i = 0; i < rh->num_ports; i++) {
        usb_port_status_t* status = &rh->port_status[i];
        if (status->wPortChange) {
            *ptr |= (1 << bit);
            have_status = true;
        }
        if (++bit == 8) {
            ptr++;
            bit = 0;
        }
    }

    if (have_status) {
        size_t length = txn->length;
        if (length > sizeof(status_bits)) length = sizeof(status_bits);
        iotxn_copyto(txn, status_bits, length, 0);
        iotxn_complete(txn, ZX_OK, length);
    } else {
        // queue transaction until we have something to report
        list_add_tail(&rh->pending_intr_reqs, &txn->node);
    }
}

zx_status_t xhci_rh_iotxn_queue(xhci_t* xhci, iotxn_t* txn, int rh_index) {
    dprintf(TRACE, "xhci_rh_iotxn_queue rh_index: %d\n", rh_index);

    usb_protocol_data_t* data = iotxn_pdata(txn, usb_protocol_data_t);
    xhci_root_hub_t* rh = &xhci->root_hubs[rh_index];

    uint8_t ep_index = xhci_endpoint_index(data->ep_address);
    if (ep_index == 0) {
        return xhci_rh_control(xhci, rh, &data->setup, txn);
    } else if (ep_index == 2) {
        xhci_rh_handle_intr_req(rh, txn);
        return ZX_OK;
    }

    iotxn_complete(txn, ZX_ERR_NOT_SUPPORTED, 0);
    return ZX_ERR_NOT_SUPPORTED;
}

void xhci_handle_root_hub_change(xhci_t* xhci) {
    volatile xhci_port_regs_t* port_regs = xhci->op_regs->port_regs;

    dprintf(TRACE, "xhci_handle_root_hub_change\n");

    for (uint32_t i = 0; i < xhci->rh_num_ports; i++) {
        uint32_t portsc = XHCI_READ32(&port_regs[i].portsc);
        uint32_t speed = (portsc & XHCI_MASK(PORTSC_SPEED_START, PORTSC_SPEED_BITS)) >> PORTSC_SPEED_START;
        uint32_t status_bits = portsc & PORTSC_STATUS_BITS;

        if (driver_get_log_flags() & DDK_LOG_SPEW) {
            print_portsc(i, portsc);
        }

        if (status_bits) {
            bool connected = !!(portsc & PORTSC_CCS);
            bool enabled = !!(portsc & PORTSC_PED);

            // set change bits to acknowledge
            XHCI_WRITE32(&port_regs[i].portsc, (portsc & PORTSC_CONTROL_BITS) | status_bits);

            // map index to virtual root hub and port number
            int rh_index = xhci->rh_map[i];
            xhci_root_hub_t* rh = &xhci->root_hubs[rh_index];
            int port_index = xhci->rh_port_map[i];
            usb_port_status_t* status = &rh->port_status[port_index];

            if (portsc & PORTSC_CSC) {
                // connect status change
                dprintf(TRACE, "port %d PORTSC_CSC connected: %d\n", i, connected);
                if (connected) {
                     status->wPortStatus |= USB_PORT_CONNECTION;
                } else {
                    if (status->wPortStatus & USB_PORT_ENABLE) {
                        status->wPortChange |= USB_C_PORT_ENABLE;
                    }
                    status->wPortStatus = 0;
                }
                status->wPortChange |= USB_C_PORT_CONNECTION;
            }
            if (portsc & PORTSC_PRC) {
                // port reset change
                dprintf(TRACE, "port %d PORTSC_PRC enabled: %d\n", i, enabled);
                if (enabled) {
                    status->wPortStatus &= ~USB_PORT_RESET;
                    status->wPortChange |= USB_C_PORT_RESET;
                    if (!(status->wPortStatus & USB_PORT_ENABLE)) {
                        status->wPortStatus |= USB_PORT_ENABLE;
                        status->wPortChange |= USB_C_PORT_ENABLE;
                    }

                    if (speed == USB_SPEED_LOW) {
                        status->wPortStatus |= USB_PORT_LOW_SPEED;
                    } else if (speed == USB_SPEED_HIGH) {
                        status->wPortStatus |= USB_PORT_HIGH_SPEED;
                    }
                }
            }

            if (status->wPortChange) {
                iotxn_t* txn = list_remove_head_type(&rh->pending_intr_reqs, iotxn_t, node);
                if (txn) {
                    xhci_rh_handle_intr_req(rh, txn);
                }
            }
        }
    }
}