source: mainline/uspace/lib/usbhost/src/bus.c@ eec201d

/*
 * Copyright (c) 2018 Ondrej Hlavaty, Petr Manek
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libusbhost
 * @{
 */
/** @file
 *
 * The Bus is a structure that serves as an interface of the HC driver
 * implementation for the usbhost library. Every HC driver that uses libusbhost
 * must use a bus_t (or its child), fill it with bus_ops and present it to the
 * library. The library then handles the DDF interface and translates it to the
 * bus callbacks.
 */

#include <ddf/driver.h>
#include <errno.h>
#include <mem.h>
#include <macros.h>
#include <stdio.h>
#include <str_error.h>
#include <usb/debug.h>
#include <usb/dma_buffer.h>

#include "endpoint.h"
#include "bus.h"

/**
 * Initializes the base bus structure.
 */
void bus_init(bus_t *bus, size_t device_size)
{
        assert(bus);
        assert(device_size >= sizeof(device_t));
        memset(bus, 0, sizeof(bus_t));

        fibril_mutex_initialize(&bus->guard);
        bus->device_size = device_size;
}

/**
 * Initialize the device_t structure belonging to a bus.
 */
int bus_device_init(device_t *dev, bus_t *bus)
{
        assert(bus);

        memset(dev, 0, sizeof(*dev));

        dev->bus = bus;

        link_initialize(&dev->link);
        list_initialize(&dev->devices);
        fibril_mutex_initialize(&dev->guard);

        return EOK;
}

/**
 * Create a name of the ddf function node.
 */
int bus_device_set_default_name(device_t *dev)
{
        assert(dev);
        assert(dev->fun);

        char buf[12] = { 0 }; /* usbxyz-ss */
        snprintf(buf, sizeof(buf), "usb%u-%cs",
            dev->address, usb_str_speed(dev->speed)[0]);

        return ddf_fun_set_name(dev->fun, buf);
}

/**
 * Setup devices Transaction Translation.
 *
 * This applies for Low/Full speed devices under High speed hub only. Other
 * devices just inherit TT from the hub.
 *
 * Roothub must be handled specially.
 */
static void device_setup_tt(device_t *dev)
{
        if (!dev->hub)
                return;

        if (dev->hub->speed == USB_SPEED_HIGH && usb_speed_is_11(dev->speed)) {
                /* For LS devices under HS hub */
                dev->tt.dev = dev->hub;
                dev->tt.port = dev->port;
        } else {
                /* Inherit hub's TT */
                dev->tt = dev->hub->tt;
        }
}

/**
 * Invoke the device_enumerate bus operation.
 *
 * There's no need to synchronize here, because no one knows the device yet.
 */
int bus_device_enumerate(device_t *dev)
{
        assert(dev);

        if (!dev->bus->ops->device_enumerate)
                return ENOTSUP;

        if (dev->online)
                return EINVAL;

        device_setup_tt(dev);

        const int r = dev->bus->ops->device_enumerate(dev);
        if (r)
                return r;

        dev->online = true;

        if (dev->hub) {
                fibril_mutex_lock(&dev->hub->guard);
                list_append(&dev->link, &dev->hub->devices);
                fibril_mutex_unlock(&dev->hub->guard);
        }

        return EOK;
}

/**
 * Clean endpoints and children that could have been left behind after
 * asking the driver of device to offline/remove a device.
 *
 * Note that EP0's lifetime is shared with the device, and as such is not
 * touched.
 */
static void device_clean_ep_children(device_t *dev, const char *op)
{
        assert(fibril_mutex_is_locked(&dev->guard));

        /* Unregister endpoints left behind. */
        for (usb_endpoint_t i = 1; i < USB_ENDPOINT_MAX; ++i) {
                if (!dev->endpoints[i])
                        continue;

                usb_log_warning("USB device '%s' driver left endpoint %u registered after %s.",
                    ddf_fun_get_name(dev->fun), i, op);

                endpoint_t *const ep = dev->endpoints[i];
                endpoint_add_ref(ep);

                fibril_mutex_unlock(&dev->guard);
                const int err = bus_endpoint_remove(ep);
                if (err)
                        usb_log_warning("Endpoint %u cannot be removed. "
                            "Some deffered cleanup was faster?", ep->endpoint);

                endpoint_del_ref(ep);
                fibril_mutex_lock(&dev->guard);
        }

        for (usb_endpoint_t i = 1; i < USB_ENDPOINT_MAX; ++i)
                assert(dev->endpoints[i] == NULL);

        /* Remove also orphaned children. */
        while (!list_empty(&dev->devices)) {
                device_t *const child = list_get_instance(list_first(&dev->devices), device_t, link);

                /*
                 * This is not an error condition, as devices cannot remove
                 * their children devices while they are removed, because for
                 * DDF, they are siblings.
                 */
                usb_log_debug("USB device '%s' driver left device '%s' behind after %s.",
                    ddf_fun_get_name(dev->fun), ddf_fun_get_name(child->fun), op);

                /*
                 * The child node won't disappear, because its parent's driver
                 * is already dead. And the child will need the guard to remove
                 * itself from the list.
                 */
                fibril_mutex_unlock(&dev->guard);
                bus_device_gone(child);
                fibril_mutex_lock(&dev->guard);
        }
        assert(list_empty(&dev->devices));
}

/**
 * Resolve a USB device that is gone.
 */
void bus_device_gone(device_t *dev)
{
        assert(dev);
        assert(dev->fun != NULL);

        const bus_ops_t *ops = dev->bus->ops;

        /* First, block new transfers and operations. */
        fibril_mutex_lock(&dev->guard);
        dev->online = false;

        /* Unbinding will need guard unlocked. */
        fibril_mutex_unlock(&dev->guard);

        /* Remove our device from our hub's children. */
        if (dev->hub) {
                fibril_mutex_lock(&dev->hub->guard);
                list_remove(&dev->link);
                fibril_mutex_unlock(&dev->hub->guard);
        }

        /*
         * Unbind the DDF function. That will result in dev_gone called in
         * driver, which shall destroy its pipes and remove its children.
         */
        const int err = ddf_fun_unbind(dev->fun);
        if (err) {
                usb_log_error("Failed to unbind USB device '%s': %s",
                    ddf_fun_get_name(dev->fun), str_error(err));
                return;
        }

        /* Remove what driver left behind */
        fibril_mutex_lock(&dev->guard);
        device_clean_ep_children(dev, "removing");

        /* Tell the HC to release its resources. */
        if (ops->device_gone)
                ops->device_gone(dev);

        /* Check whether the driver didn't forgot EP0 */
        if (dev->endpoints[0]) {
                if (ops->endpoint_unregister)
                        ops->endpoint_unregister(dev->endpoints[0]);
                /* Release the EP0 bus reference */
                endpoint_del_ref(dev->endpoints[0]);
        }

        /* Destroy the function, freeing also the device, unlocking mutex. */
        ddf_fun_destroy(dev->fun);
}

/**
 * The user wants this device back online.
 */
int bus_device_online(device_t *dev)
{
        int rc;
        assert(dev);

        fibril_mutex_lock(&dev->guard);
        if (dev->online) {
                rc = EINVAL;
                goto err_lock;
        }

        /* First, tell the HC driver. */
        const bus_ops_t *ops = dev->bus->ops;
        if (ops->device_online && (rc = ops->device_online(dev))) {
                usb_log_warning("Host controller failed to make device '%s' online: %s",
                    ddf_fun_get_name(dev->fun), str_error(rc));
                goto err_lock;
        }

        /* Allow creation of new endpoints and communication with the device. */
        dev->online = true;

        /* Onlining will need the guard */
        fibril_mutex_unlock(&dev->guard);

        if ((rc = ddf_fun_online(dev->fun))) {
                usb_log_warning("Failed to take device '%s' online: %s",
                    ddf_fun_get_name(dev->fun), str_error(rc));
                goto err;
        }

        usb_log_info("USB Device '%s' is now online.", ddf_fun_get_name(dev->fun));
        return EOK;

err_lock:
        fibril_mutex_unlock(&dev->guard);
err:
        return rc;
}

/**
 * The user requested to take this device offline.
 */
int bus_device_offline(device_t *dev)
{
        int rc;
        assert(dev);

        /* Make sure we're the one who offlines this device */
        if (!dev->online) {
                rc = ENOENT;
                goto err;
        }

        /*
         * XXX: If the device is removed/offlined just now, this can fail on
         * assertion. We most probably need some kind of enum status field to
         * make the synchronization work.
         */

        /* Tear down all drivers working with the device. */
        if ((rc = ddf_fun_offline(dev->fun))) {
                goto err;
        }

        fibril_mutex_lock(&dev->guard);
        dev->online = false;
        device_clean_ep_children(dev, "offlining");

        /* Tell also the HC driver. */
        const bus_ops_t *ops = dev->bus->ops;
        if (ops->device_offline)
                ops->device_offline(dev);

        fibril_mutex_unlock(&dev->guard);
        usb_log_info("USB Device '%s' is now offline.", ddf_fun_get_name(dev->fun));
        return EOK;

err:
        return rc;
}

/**
 * Calculate an index to the endpoint array.
 * For the default control endpoint 0, it must return 0.
 * For different arguments, the result is stable but not defined.
 */
static size_t bus_endpoint_index(usb_endpoint_t ep, usb_direction_t dir)
{
        return 2 * ep + (dir == USB_DIRECTION_OUT);
}

/**
 * Create and register new endpoint to the bus.
 *
 * @param[in] device The device of which the endpoint shall be created
 * @param[in] desc Endpoint descriptors as reported by the device
 * @param[out] out_ep The resulting new endpoint reference, if any. Can be NULL.
 */
int bus_endpoint_add(device_t *device, const usb_endpoint_descriptors_t *desc, endpoint_t **out_ep)
{
        int err;
        assert(device);

        bus_t *bus = device->bus;

        if (!bus->ops->endpoint_register)
                return ENOTSUP;

        endpoint_t *ep;
        if (bus->ops->endpoint_create) {
                ep = bus->ops->endpoint_create(device, desc);
                if (!ep)
                        return ENOMEM;
        } else {
                ep = calloc(1, sizeof(endpoint_t));
                if (!ep)
                        return ENOMEM;
                endpoint_init(ep, device, desc);
        }

        assert((ep->required_transfer_buffer_policy & ~ep->transfer_buffer_policy) == 0);

        /* Bus reference */
        endpoint_add_ref(ep);

        const size_t idx = bus_endpoint_index(ep->endpoint, ep->direction);
        if (idx >= ARRAY_SIZE(device->endpoints)) {
                usb_log_warning("Invalid endpoint description (ep no %u out of "
                    "bounds)", ep->endpoint);
                goto drop;
        }

        if (ep->max_transfer_size == 0) {
                usb_log_warning("Invalid endpoint description (mps %zu, "
                    "%u packets)", ep->max_packet_size, ep->packets_per_uframe);
                goto drop;
        }

        usb_log_debug("Register endpoint %d:%d %s-%s %zuB.",
            device->address, ep->endpoint,
            usb_str_transfer_type(ep->transfer_type),
            usb_str_direction(ep->direction),
            ep->max_transfer_size);

        fibril_mutex_lock(&device->guard);
        if (!device->online && ep->endpoint != 0) {
                err = EAGAIN;
        } else if (device->endpoints[idx] != NULL) {
                err = EEXIST;
        } else {
                err = bus->ops->endpoint_register(ep);
                if (!err)
                        device->endpoints[idx] = ep;
        }
        fibril_mutex_unlock(&device->guard);
        if (err) {
                endpoint_del_ref(ep);
                return err;
        }

        if (out_ep) {
                /* Exporting reference */
                endpoint_add_ref(ep);
                *out_ep = ep;
        }

        return EOK;
drop:
        /* Bus reference */
        endpoint_del_ref(ep);
        return EINVAL;
}

/**
 * Search for an endpoint. Returns a reference.
 */
endpoint_t *bus_find_endpoint(device_t *device, usb_endpoint_t endpoint,
    usb_direction_t dir)
{
        assert(device);

        const size_t idx = bus_endpoint_index(endpoint, dir);
        const size_t ctrl_idx = bus_endpoint_index(endpoint, USB_DIRECTION_BOTH);

        endpoint_t *ep = NULL;

        fibril_mutex_lock(&device->guard);
        if (idx < ARRAY_SIZE(device->endpoints))
                ep = device->endpoints[idx];
        /*
         * If the endpoint was not found, it's still possible it is a control
         * endpoint having direction BOTH.
         */
        if (!ep && ctrl_idx < ARRAY_SIZE(device->endpoints)) {
                ep = device->endpoints[ctrl_idx];
                if (ep && ep->transfer_type != USB_TRANSFER_CONTROL)
                        ep = NULL;
        }
        if (ep) {
                /* Exporting reference */
                endpoint_add_ref(ep);
        }
        fibril_mutex_unlock(&device->guard);
        return ep;
}

/**
 * Remove an endpoint from the device.
 */
int bus_endpoint_remove(endpoint_t *ep)
{
        assert(ep);
        assert(ep->device);

        device_t *device = ep->device;
        if (!device)
                return ENOENT;

        bus_t *bus = device->bus;

        if (!bus->ops->endpoint_unregister)
                return ENOTSUP;

        usb_log_debug("Unregister endpoint %d:%d %s-%s %zuB.",
            device->address, ep->endpoint,
            usb_str_transfer_type(ep->transfer_type),
            usb_str_direction(ep->direction),
            ep->max_transfer_size);

        const size_t idx = bus_endpoint_index(ep->endpoint, ep->direction);

        if (idx >= ARRAY_SIZE(device->endpoints))
                return EINVAL;

        fibril_mutex_lock(&device->guard);

        /* Check whether the endpoint is registered */
        if (device->endpoints[idx] != ep) {
                fibril_mutex_unlock(&device->guard);
                return EINVAL;
        }

        bus->ops->endpoint_unregister(ep);
        device->endpoints[idx] = NULL;
        fibril_mutex_unlock(&device->guard);

        /* Bus reference */
        endpoint_del_ref(ep);

        return EOK;
}

/**
 * Reserve the default address on the bus for the specified device (hub).
 */
int bus_reserve_default_address(bus_t *bus, device_t *dev)
{
        assert(bus);

        int err;
        fibril_mutex_lock(&bus->guard);
        if (bus->default_address_owner != NULL) {
                err = (bus->default_address_owner == dev) ? EINVAL : EAGAIN;
        } else {
                bus->default_address_owner = dev;
                err = EOK;
        }
        fibril_mutex_unlock(&bus->guard);
        return err;
}

/**
 * Release the default address.
 */
void bus_release_default_address(bus_t *bus, device_t *dev)
{
        assert(bus);

        fibril_mutex_lock(&bus->guard);
        if (bus->default_address_owner != dev) {
                usb_log_error("Device %d tried to release default address, "
                    "which is not reserved for it.", dev->address);
        } else {
                bus->default_address_owner = NULL;
        }
        fibril_mutex_unlock(&bus->guard);
}

/**
 * Assert some conditions on transfer request. As the request is an entity of
 * HC driver only, we can force these conditions harder. Invalid values from
 * devices shall be caught on DDF interface already.
 */
static void check_request(const transfer_request_t *request)
{
        assert(usb_target_is_valid(&request->target));
        assert(request->dir != USB_DIRECTION_BOTH);
        /* Non-zero offset => size is non-zero */
        assert(request->offset == 0 || request->size != 0);
        /* Non-zero size => buffer is set */
        assert(request->size == 0 || dma_buffer_is_set(&request->buffer));
        /* Non-null arg => callback is set */
        assert(request->arg == NULL || request->on_complete != NULL);
        assert(request->name);
}

/**
 * Initiate a transfer with given device.
 *
 * @return Error code.
 */
int bus_issue_transfer(device_t *device, const transfer_request_t *request)
{
        assert(device);
        assert(request);

        check_request(request);
        assert(device->address == request->target.address);

        /* Temporary reference */
        endpoint_t *ep = bus_find_endpoint(device, request->target.endpoint, request->dir);
        if (ep == NULL) {
                usb_log_error("Endpoint(%d:%d) not registered for %s.",
                    device->address, request->target.endpoint, request->name);
                return ENOENT;
        }

        assert(ep->device == device);

        const int err = endpoint_send_batch(ep, request);

        /* Temporary reference */
        endpoint_del_ref(ep);

        return err;
}

/**
 * A structure to pass data from the completion callback to the caller.
 */
typedef struct {
        fibril_mutex_t done_mtx;
        fibril_condvar_t done_cv;
        bool done;

        size_t transferred_size;
        int error;
} sync_data_t;

/**
 * Callback for finishing the transfer. Wake the issuing thread.
 */
static int sync_transfer_complete(void *arg, int error, size_t transferred_size)
{
        sync_data_t *d = arg;
        assert(d);
        d->transferred_size = transferred_size;
        d->error = error;
        fibril_mutex_lock(&d->done_mtx);
        d->done = true;
        fibril_condvar_broadcast(&d->done_cv);
        fibril_mutex_unlock(&d->done_mtx);
        return EOK;
}

/**
 * Issue a transfer on the bus, wait for the result.
 *
 * @param device Device for which to send the batch
 * @param target The target of the transfer.
 * @param direction A direction of the transfer.
 * @param data A pointer to the data buffer.
 * @param size Size of the data buffer.
 * @param setup_data Data to use in the setup stage (Control communication type)
 * @param name Communication identifier (for nicer output).
 */
errno_t bus_device_send_batch_sync(device_t *device, usb_target_t target,
    usb_direction_t direction, char *data, size_t size, uint64_t setup_data,
    const char *name, size_t *transferred_size)
{
        int err;
        sync_data_t sd = { .done = false };
        fibril_mutex_initialize(&sd.done_mtx);
        fibril_condvar_initialize(&sd.done_cv);

        transfer_request_t request = {
                .target = target,
                .dir = direction,
                .offset = ((uintptr_t) data) % PAGE_SIZE,
                .size = size,
                .setup = setup_data,
                .on_complete = sync_transfer_complete,
                .arg = &sd,
                .name = name,
        };

        if (data &&
            (err = dma_buffer_lock(&request.buffer, data - request.offset, size)))
                return err;

        if ((err = bus_issue_transfer(device, &request))) {
                dma_buffer_unlock(&request.buffer, size);
                return err;
        }

        /*
         * Note: There are requests that are completed synchronously. It is not
         *       therefore possible to just lock the mutex before and wait.
         */
        fibril_mutex_lock(&sd.done_mtx);
        while (!sd.done)
                fibril_condvar_wait(&sd.done_cv, &sd.done_mtx);
        fibril_mutex_unlock(&sd.done_mtx);

        dma_buffer_unlock(&request.buffer, size);

        if (transferred_size)
                *transferred_size = sd.transferred_size;

        return sd.error;
}

/**
 * @}
 */