source: mainline/uspace/lib/usbdev/include/usb/dev/poll.h@ 8624d1f

/*
 * SPDX-FileCopyrightText: 2011 Vojtech Horky
 * SPDX-FileCopyrightText: 2017 Petr Manek
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/** @addtogroup libusbdev
 * @{
 */
/** @file
 * USB device polling functions.
 */
#ifndef LIBUSBDEV_POLL_H_
#define LIBUSBDEV_POLL_H_

#include <usb/usb.h>
#include <usb/dev/device.h>
#include <usb/dev/pipes.h>

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <fibril_synch.h>

/** USB automated polling. */
typedef struct usb_polling {
        /** Mandatory parameters - user is expected to configure these. */

        /** USB device to poll. */
        usb_device_t *device;

        /** Device enpoint mapping to use for polling. */
        usb_endpoint_mapping_t *ep_mapping;

        /** Size of the recieved data. */
        size_t request_size;

        /**
         * Data buffer of at least `request_size`. User is responsible for its
         * allocation.
         */
        uint8_t *buffer;

        /** Callback when data arrives.
         *
         * @param dev Device that was polled.
         * @param data Data buffer (in USB endianness).
         * @param data_size Size of the @p data buffer in bytes.
         * @param arg Custom argument.
         * @return Whether to continue in polling.
         */
        bool (*on_data)(usb_device_t *dev, uint8_t *data, size_t data_size,
            void *arg);

        /**
         * Optional parameters - user can customize them, but they are
         * defaulted to  some reasonable values.
         */

        /** Level of debugging messages from auto polling.
         * 0 - nothing (default)
         * 1 - inform about errors and polling start/end
         * 2 - also dump every retrieved buffer
         */
        int debug;

        /**
         * Maximum number of consecutive errors before polling termination
         * (default 3).
         */
        size_t max_failures;

        /** Delay between poll requests in milliseconds.
         * By default, value from endpoint descriptor used.
         */
        int delay;

        /** Whether to automatically try to clear the HALT feature after
         * the endpoint stalls (true by default).
         */
        bool auto_clear_halt;

        /** Argument to pass to callbacks (default NULL). */
        void *arg;

        /** Callback when polling is terminated.
         *
         * @param dev Device where the polling was terminated.
         * @param due_to_errors Whether polling stopped due to several failures.
         * @param arg Custom argument.
         */
        void (*on_polling_end)(usb_device_t *dev, bool due_to_errors,
            void *arg);

        /** Callback when error occurs.
         *
         * @param dev Device where error occurred.
         * @param err_code Error code (as returned from usb_pipe_read).
         * @param arg Custom argument.
         * @return Whether to continue in polling.
         */
        bool (*on_error)(usb_device_t *dev, errno_t err_code, void *arg);

        /**
         * Internal parameters - user is not expected to set them. Messing with
         * them can result in unexpected behavior if you do not know what you
         * are doing.
         */

        /** Fibril used for polling. */
        fid_t fibril;

        /** True if polling is currently in operation. */
        volatile bool running;

        /** True if polling should terminate as soon as possible. */
        volatile bool joining;

        /** Synchronization primitives for joining polling end. */
        fibril_mutex_t guard;
        fibril_condvar_t cv;
} usb_polling_t;

errno_t usb_polling_init(usb_polling_t *);
void usb_polling_fini(usb_polling_t *);

errno_t usb_polling_start(usb_polling_t *);
errno_t usb_polling_join(usb_polling_t *);

#endif
/**
 * @}
 */