// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2003
 * Gerry Hamel, geh@ti.com, Texas Instruments
 *
 * Based on
 * linux/drivers/usbd/usbd.c.c - USB Device Core Layer
 *
 * Copyright (c) 2000, 2001, 2002 Lineo
 * Copyright (c) 2001 Hewlett Packard
 *
 * By:
 *      Stuart Lynne <sl@lineo.com>,
 *      Tom Rushworth <tbr@lineo.com>,
 *      Bruce Balden <balden@lineo.com>
 */

#include <log.h>
#include <malloc.h>
#include <serial.h>
#include <usbdevice.h>

#define MAX_INTERFACES 2


int maxstrings = 20;

/* Global variables ************************************************************************** */

struct usb_string_descriptor **usb_strings;

int usb_devices;

extern struct usb_function_driver ep0_driver;

int registered_functions;
int registered_devices;

__maybe_unused static char *usbd_device_events[] = {
        "DEVICE_UNKNOWN",
        "DEVICE_INIT",
        "DEVICE_CREATE",
        "DEVICE_HUB_CONFIGURED",
        "DEVICE_RESET",
        "DEVICE_ADDRESS_ASSIGNED",
        "DEVICE_CONFIGURED",
        "DEVICE_SET_INTERFACE",
        "DEVICE_SET_FEATURE",
        "DEVICE_CLEAR_FEATURE",
        "DEVICE_DE_CONFIGURED",
        "DEVICE_BUS_INACTIVE",
        "DEVICE_BUS_ACTIVITY",
        "DEVICE_POWER_INTERRUPTION",
        "DEVICE_HUB_RESET",
        "DEVICE_DESTROY",
        "DEVICE_FUNCTION_PRIVATE",
};

__maybe_unused static char *usbd_device_status[] = {
        "USBD_OPENING",
        "USBD_OK",
        "USBD_SUSPENDED",
        "USBD_CLOSING",
};

#define USBD_DEVICE_STATUS(x) (((unsigned int)x <= USBD_CLOSING) ? usbd_device_status[x] : "UNKNOWN")


/* Descriptor support functions ************************************************************** */


/**
 * usbd_get_string - find and return a string descriptor
 * @index: string index to return
 *
 * Find an indexed string and return a pointer to a it.
 */
struct usb_string_descriptor *usbd_get_string (__u8 index)
{
        if (index >= maxstrings) {
                return NULL;
        }
        return usb_strings[index];
}


/* Access to device descriptor functions ***************************************************** */


/* *
 * usbd_device_configuration_instance - find a configuration instance for this device
 * @device:
 * @configuration: index to configuration, 0 - N-1
 *
 * Get specifed device configuration. Index should be bConfigurationValue-1.
 */
static struct usb_configuration_instance *usbd_device_configuration_instance (struct usb_device_instance *device,
                unsigned int port, unsigned int configuration)
{
        if (configuration >= device->configurations)
                return NULL;

        return device->configuration_instance_array + configuration;
}


/* *
 * usbd_device_interface_instance
 * @device:
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 *
 * Return the specified interface descriptor for the specified device.
 */
struct usb_interface_instance *usbd_device_interface_instance (struct usb_device_instance *device, int port, int configuration, int interface)
{
        struct usb_configuration_instance *configuration_instance;

        if ((configuration_instance = usbd_device_configuration_instance (device, port, configuration)) == NULL) {
                return NULL;
        }
        if (interface >= configuration_instance->interfaces) {
                return NULL;
        }
        return configuration_instance->interface_instance_array + interface;
}

/* *
 * usbd_device_alternate_descriptor_list
 * @device:
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 * @alternate: alternate setting
 *
 * Return the specified alternate descriptor for the specified device.
 */
struct usb_alternate_instance *usbd_device_alternate_instance (struct usb_device_instance *device, int port, int configuration, int interface, int alternate)
{
        struct usb_interface_instance *interface_instance;

        if ((interface_instance = usbd_device_interface_instance (device, port, configuration, interface)) == NULL) {
                return NULL;
        }

        if (alternate >= interface_instance->alternates) {
                return NULL;
        }

        return interface_instance->alternates_instance_array + alternate;
}


/* *
 * usbd_device_device_descriptor
 * @device: which device
 * @configuration: index to configuration, 0 - N-1
 * @port: which port
 *
 * Return the specified configuration descriptor for the specified device.
 */
struct usb_device_descriptor *usbd_device_device_descriptor (struct usb_device_instance *device, int port)
{
        return (device->device_descriptor);
}

/**
 * usbd_device_configuration_descriptor
 * @device: which device
 * @port: which port
 * @configuration: index to configuration, 0 - N-1
 *
 * Return the specified configuration descriptor for the specified device.
 */
struct usb_configuration_descriptor *usbd_device_configuration_descriptor (struct
                                                                           usb_device_instance
                                                                           *device, int port, int configuration)
{
        struct usb_configuration_instance *configuration_instance;
        if (!(configuration_instance = usbd_device_configuration_instance (device, port, configuration))) {
                return NULL;
        }
        return (configuration_instance->configuration_descriptor);
}


/**
 * usbd_device_interface_descriptor
 * @device: which device
 * @port: which port
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 * @alternate: alternate setting
 *
 * Return the specified interface descriptor for the specified device.
 */
struct usb_interface_descriptor *usbd_device_interface_descriptor (struct usb_device_instance
                                                                   *device, int port, int configuration, int interface, int alternate)
{
        struct usb_interface_instance *interface_instance;
        if (!(interface_instance = usbd_device_interface_instance (device, port, configuration, interface))) {
                return NULL;
        }
        if ((alternate < 0) || (alternate >= interface_instance->alternates)) {
                return NULL;
        }
        return (interface_instance->alternates_instance_array[alternate].interface_descriptor);
}

/**
 * usbd_device_endpoint_descriptor_index
 * @device: which device
 * @port: which port
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 * @alternate: index setting
 * @index: which index
 *
 * Return the specified endpoint descriptor for the specified device.
 */
struct usb_endpoint_descriptor *usbd_device_endpoint_descriptor_index (struct usb_device_instance
                                                                       *device, int port, int configuration, int interface, int alternate, int index)
{
        struct usb_alternate_instance *alternate_instance;

        if (!(alternate_instance = usbd_device_alternate_instance (device, port, configuration, interface, alternate))) {
                return NULL;
        }
        if (index >= alternate_instance->endpoints) {
                return NULL;
        }
        return *(alternate_instance->endpoints_descriptor_array + index);
}


/**
 * usbd_device_endpoint_transfersize
 * @device: which device
 * @port: which port
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 * @index: which index
 *
 * Return the specified endpoint transfer size;
 */
int usbd_device_endpoint_transfersize (struct usb_device_instance *device, int port, int configuration, int interface, int alternate, int index)
{
        struct usb_alternate_instance *alternate_instance;

        if (!(alternate_instance = usbd_device_alternate_instance (device, port, configuration, interface, alternate))) {
                return 0;
        }
        if (index >= alternate_instance->endpoints) {
                return 0;
        }
        return *(alternate_instance->endpoint_transfersize_array + index);
}


/**
 * usbd_device_endpoint_descriptor
 * @device: which device
 * @port: which port
 * @configuration: index to configuration, 0 - N-1
 * @interface: index to interface
 * @alternate: alternate setting
 * @endpoint: which endpoint
 *
 * Return the specified endpoint descriptor for the specified device.
 */
struct usb_endpoint_descriptor *usbd_device_endpoint_descriptor (struct usb_device_instance *device, int port, int configuration, int interface, int alternate, int endpoint)
{
        struct usb_endpoint_descriptor *endpoint_descriptor;
        int i;

        for (i = 0; !(endpoint_descriptor = usbd_device_endpoint_descriptor_index (device, port, configuration, interface, alternate, i)); i++) {
                if (endpoint_descriptor->bEndpointAddress == endpoint) {
                        return endpoint_descriptor;
                }
        }
        return NULL;
}

/**
 * usbd_endpoint_halted
 * @device: point to struct usb_device_instance
 * @endpoint: endpoint to check
 *
 * Return non-zero if endpoint is halted.
 */
int usbd_endpoint_halted (struct usb_device_instance *device, int endpoint)
{
        return (device->status == USB_STATUS_HALT);
}


/**
 * usbd_rcv_complete - complete a receive
 * @endpoint:
 * @len:
 * @urb_bad:
 *
 * Called from rcv interrupt to complete.
 */
void usbd_rcv_complete(struct usb_endpoint_instance *endpoint, int len, int urb_bad)
{
        if (endpoint) {
                struct urb *rcv_urb;

                /*usbdbg("len: %d urb: %p\n", len, endpoint->rcv_urb); */

                /* if we had an urb then update actual_length, dispatch if neccessary */
                if ((rcv_urb = endpoint->rcv_urb)) {

                        /*usbdbg("actual: %d buffer: %d\n", */
                        /*rcv_urb->actual_length, rcv_urb->buffer_length); */

                        /* check the urb is ok, are we adding data less than the packetsize */
                        if (!urb_bad && (len <= endpoint->rcv_packetSize)) {
                          /*usbdbg("updating actual_length by %d\n",len); */

                                /* increment the received data size */
                                rcv_urb->actual_length += len;

                        } else {
                                usberr(" RECV_ERROR actual: %d buffer: %d urb_bad: %d\n",
                                       rcv_urb->actual_length, rcv_urb->buffer_length, urb_bad);

                                rcv_urb->actual_length = 0;
                                rcv_urb->status = RECV_ERROR;
                        }
                } else {
                        usberr("no rcv_urb!");
                }
        } else {
                usberr("no endpoint!");
        }

}

/**
 * usbd_tx_complete - complete a transmit
 * @endpoint:
 * @resetart:
 *
 * Called from tx interrupt to complete.
 */
void usbd_tx_complete (struct usb_endpoint_instance *endpoint)
{
        if (endpoint) {
                struct urb *tx_urb;

                /* if we have a tx_urb advance or reset, finish if complete */
                if ((tx_urb = endpoint->tx_urb)) {
                        int sent = endpoint->last;
                        endpoint->sent += sent;
                        endpoint->last -= sent;

                        if( (endpoint->tx_urb->actual_length - endpoint->sent) <= 0 ) {
                                tx_urb->actual_length = 0;
                                endpoint->sent = 0;
                                endpoint->last = 0;

                                /* Remove from active, save for re-use */
                                urb_detach(tx_urb);
                                urb_append(&endpoint->done, tx_urb);
                                /*usbdbg("done->next %p, tx_urb %p, done %p", */
                                /*       endpoint->done.next, tx_urb, &endpoint->done); */

                                endpoint->tx_urb = first_urb_detached(&endpoint->tx);
                                if( endpoint->tx_urb ) {
                                        endpoint->tx_queue--;
                                        usbdbg("got urb from tx list");
                                }
                                if( !endpoint->tx_urb ) {
                                        /*usbdbg("taking urb from done list"); */
                                        endpoint->tx_urb = first_urb_detached(&endpoint->done);
                                }
                                if( !endpoint->tx_urb ) {
                                        usbdbg("allocating new urb for tx_urb");
                                        endpoint->tx_urb = usbd_alloc_urb(tx_urb->device, endpoint);
                                }
                        }
                }
        }
}

/* URB linked list functions ***************************************************** */

/*
 * Initialize an urb_link to be a single element list.
 * If the urb_link is being used as a distinguished list head
 * the list is empty when the head is the only link in the list.
 */
void urb_link_init (urb_link * ul)
{
        if (ul) {
                ul->prev = ul->next = ul;
        }
}

/*
 * Detach an urb_link from a list, and set it
 * up as a single element list, so no dangling
 * pointers can be followed, and so it can be
 * joined to another list if so desired.
 */
void urb_detach (struct urb *urb)
{
        if (urb) {
                urb_link *ul = &urb->link;
                ul->next->prev = ul->prev;
                ul->prev->next = ul->next;
                urb_link_init (ul);
        }
}

/*
 * Return the first urb_link in a list with a distinguished
 * head "hd", or NULL if the list is empty.  This will also
 * work as a predicate, returning NULL if empty, and non-NULL
 * otherwise.
 */
urb_link *first_urb_link (urb_link * hd)
{
        urb_link *nx;
        if (NULL != hd && NULL != (nx = hd->next) && nx != hd) {
                /* There is at least one element in the list */
                /* (besides the distinguished head). */
                return (nx);
        }
        /* The list is empty */
        return (NULL);
}

/*
 * Return the first urb in a list with a distinguished
 * head "hd", or NULL if the list is empty.
 */
struct urb *first_urb (urb_link * hd)
{
        urb_link *nx;
        if (NULL == (nx = first_urb_link (hd))) {
                /* The list is empty */
                return (NULL);
        }
        return (p2surround (struct urb, link, nx));
}

/*
 * Detach and return the first urb in a list with a distinguished
 * head "hd", or NULL if the list is empty.
 *
 */
struct urb *first_urb_detached (urb_link * hd)
{
        struct urb *urb;
        if ((urb = first_urb (hd))) {
                urb_detach (urb);
        }
        return urb;
}


/*
 * Append an urb_link (or a whole list of
 * urb_links) to the tail of another list
 * of urb_links.
 */
void urb_append (urb_link * hd, struct urb *urb)
{
        if (hd && urb) {
                urb_link *new = &urb->link;

                /* This allows the new urb to be a list of urbs, */
                /* with new pointing at the first, but the link */
                /* must be initialized. */
                /* Order is important here... */
                urb_link *pul = hd->prev;
                new->prev->next = hd;
                hd->prev = new->prev;
                new->prev = pul;
                pul->next = new;
        }
}

/* URB create/destroy functions ***************************************************** */

/**
 * usbd_alloc_urb - allocate an URB appropriate for specified endpoint
 * @device: device instance
 * @endpoint: endpoint
 *
 * Allocate an urb structure. The usb device urb structure is used to
 * contain all data associated with a transfer, including a setup packet for
 * control transfers.
 *
 * NOTE: endpoint_address MUST contain a direction flag.
 */
struct urb *usbd_alloc_urb (struct usb_device_instance *device,
                            struct usb_endpoint_instance *endpoint)
{
        struct urb *urb;

        if (!(urb = (struct urb *) malloc (sizeof (struct urb)))) {
                usberr (" F A T A L:  malloc(%zu) FAILED!!!!",
                        sizeof (struct urb));
                return NULL;
        }

        /* Fill in known fields */
        memset (urb, 0, sizeof (struct urb));
        urb->endpoint = endpoint;
        urb->device = device;
        urb->buffer = (u8 *) urb->buffer_data;
        urb->buffer_length = sizeof (urb->buffer_data);

        urb_link_init (&urb->link);

        return urb;
}

/**
 * usbd_dealloc_urb - deallocate an URB and associated buffer
 * @urb: pointer to an urb structure
 *
 * Deallocate an urb structure and associated data.
 */
void usbd_dealloc_urb (struct urb *urb)
{
        if (urb) {
                free (urb);
        }
}

/* Event signaling functions ***************************************************** */

/**
 * usbd_device_event - called to respond to various usb events
 * @device: pointer to struct device
 * @event: event to respond to
 *
 * Used by a Bus driver to indicate an event.
 */
void usbd_device_event_irq (struct usb_device_instance *device, usb_device_event_t event, int data)
{
        usb_device_state_t state;

        if (!device || !device->bus) {
                usberr("(%p,%d) NULL device or device->bus", device, event);
                return;
        }

        state = device->device_state;

        usbinfo("%s", usbd_device_events[event]);

        switch (event) {
        case DEVICE_UNKNOWN:
                break;
        case DEVICE_INIT:
                device->device_state = STATE_INIT;
                break;

        case DEVICE_CREATE:
                device->device_state = STATE_ATTACHED;
                break;

        case DEVICE_HUB_CONFIGURED:
                device->device_state = STATE_POWERED;
                break;

        case DEVICE_RESET:
                device->device_state = STATE_DEFAULT;
                device->address = 0;
                break;

        case DEVICE_ADDRESS_ASSIGNED:
                device->device_state = STATE_ADDRESSED;
                break;

        case DEVICE_CONFIGURED:
                device->device_state = STATE_CONFIGURED;
                break;

        case DEVICE_DE_CONFIGURED:
                device->device_state = STATE_ADDRESSED;
                break;

        case DEVICE_BUS_INACTIVE:
                if (device->status != USBD_CLOSING) {
                        device->status = USBD_SUSPENDED;
                }
                break;
        case DEVICE_BUS_ACTIVITY:
                if (device->status != USBD_CLOSING) {
                        device->status = USBD_OK;
                }
                break;

        case DEVICE_SET_INTERFACE:
                break;
        case DEVICE_SET_FEATURE:
                break;
        case DEVICE_CLEAR_FEATURE:
                break;

        case DEVICE_POWER_INTERRUPTION:
                device->device_state = STATE_POWERED;
                break;
        case DEVICE_HUB_RESET:
                device->device_state = STATE_ATTACHED;
                break;
        case DEVICE_DESTROY:
                device->device_state = STATE_UNKNOWN;
                break;

        case DEVICE_FUNCTION_PRIVATE:
                break;

        default:
                usbdbg("event %d - not handled",event);
                break;
        }
        debug("%s event: %d oldstate: %d newstate: %d status: %d address: %d",
                device->name, event, state,
                device->device_state, device->status, device->address);

        /* tell the bus interface driver */
        if( device->event ) {
                /* usbdbg("calling device->event"); */
                device->event(device, event, data);
        }
}