source: mainline/uspace/lib/usbdev/src/devpoll.c@ b81410f

/*
 * Copyright (c) 2011 Vojtech Horky
 * 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 libusbdev
 * @{
 */
/** @file
 * USB device driver framework - automatic interrupt polling.
 */
#include <usb/dev/poll.h>
#include <usb/dev/request.h>
#include <usb/debug.h>
#include <usb/classes/classes.h>
#include <errno.h>
#include <str_error.h>
#include <assert.h>

/** Maximum number of failed consecutive requests before announcing failure. */
#define MAX_FAILED_ATTEMPTS 3

/** Data needed for polling. */
typedef struct {
        usb_device_auto_polling_t auto_polling;

        usb_device_t *dev;
        size_t pipe_index;
        size_t request_size;
        uint8_t *buffer;
        void *custom_arg;
} polling_data_t;


/** Polling fibril.
 *
 * @param arg Pointer to polling_data_t.
 * @return Always EOK.
 */
static int polling_fibril(void *arg)
{
        polling_data_t *polling_data = (polling_data_t *) arg;
        assert(polling_data);

        usb_pipe_t *pipe
            = &polling_data->dev->pipes[polling_data->pipe_index].pipe;
        
        if (polling_data->auto_polling.debug > 0) {
                const usb_endpoint_mapping_t *mapping
                    = &polling_data->dev->pipes[polling_data->pipe_index];
                usb_log_debug("Poll%p: started polling of `%s' - " \
                    "interface %d (%s,%d,%d), %zuB/%zu.\n",
                    polling_data,
                    polling_data->dev->ddf_dev->name,
                    (int) mapping->interface->interface_number,
                    usb_str_class(mapping->interface->interface_class),
                    (int) mapping->interface->interface_subclass,
                    (int) mapping->interface->interface_protocol,
                    polling_data->request_size, pipe->max_packet_size);
        }

        size_t failed_attempts = 0;
        while (failed_attempts <= polling_data->auto_polling.max_failures) {
                size_t actual_size;
                const int rc = usb_pipe_read(pipe, polling_data->buffer,
                    polling_data->request_size, &actual_size);

                if (polling_data->auto_polling.debug > 1) {
                        if (rc == EOK) {
                                usb_log_debug(
                                    "Poll%p: received: '%s' (%zuB).\n",
                                    polling_data,
                                    usb_debug_str_buffer(polling_data->buffer,
                                        actual_size, 16),
                                    actual_size);
                        } else {
                                usb_log_debug(
                                    "Poll%p: polling failed: %s.\n",
                                    polling_data, str_error(rc));
                        }
                }

                /* If the pipe stalled, we can try to reset the stall. */
                if ((rc == ESTALL) && (polling_data->auto_polling.auto_clear_halt)) {
                        /*
                         * We ignore error here as this is usually a futile
                         * attempt anyway.
                         */
                        usb_request_clear_endpoint_halt(
                            &polling_data->dev->ctrl_pipe, pipe->endpoint_no);
                }

                if (rc != EOK) {
                        if (polling_data->auto_polling.on_error != NULL) {
                                bool cont = polling_data->auto_polling.on_error(
                                    polling_data->dev, rc,
                                    polling_data->custom_arg);
                                if (!cont) {
                                        failed_attempts
                                            = polling_data->auto_polling.max_failures;
                                }
                        }
                        failed_attempts++;
                        continue;
                }

                /* We have the data, execute the callback now. */
                const bool carry_on = polling_data->auto_polling.on_data(
                    polling_data->dev, polling_data->buffer, actual_size,
                    polling_data->custom_arg);

                if (!carry_on) {
                        failed_attempts = 0;
                        break;
                }

                /* Reset as something might be only a temporary problem. */
                failed_attempts = 0;

                /* Take a rest before next request. */
                async_usleep(polling_data->auto_polling.delay);
        }

        if (polling_data->auto_polling.on_polling_end != NULL) {
                polling_data->auto_polling.on_polling_end(polling_data->dev,
                    failed_attempts > 0, polling_data->custom_arg);
        }

        if (polling_data->auto_polling.debug > 0) {
                if (failed_attempts > 0) {
                        usb_log_error(
                            "Polling of device `%s' terminated: %s.\n",
                            polling_data->dev->ddf_dev->name,
                            "recurring failures");
                } else {
                        usb_log_debug(
                            "Polling of device `%s' terminated by user.\n",
                            polling_data->dev->ddf_dev->name
                        );
                }
        }

        /* Free the allocated memory. */
        free(polling_data->buffer);
        free(polling_data);

        return EOK;
}

/** Start automatic device polling over interrupt in pipe.
 *
 * @warning It is up to the callback to produce delays between individual
 * requests.
 *
 * @warning There is no guarantee when the request to the device
 * will be sent for the first time (it is possible that this
 * first request would be executed prior to return from this function).
 *
 * @param dev Device to be periodically polled.
 * @param pipe_index Index of the endpoint pipe used for polling.
 * @param callback Callback when data are available.
 * @param request_size How many bytes to ask for in each request.
 * @param terminated_callback Callback when polling is terminated.
 * @param arg Custom argument (passed as is to the callbacks).
 * @return Error code.
 * @retval EOK New fibril polling the device was already started.
 */
int usb_device_auto_poll(usb_device_t *dev, size_t pipe_index,
    usb_polling_callback_t callback, size_t request_size,
    usb_polling_terminted_callback_t terminated_callback, void *arg)
{
        const usb_device_auto_polling_t auto_polling = {
                .debug = 1,
                .auto_clear_halt = true,
                .delay = 0,
                .max_failures = MAX_FAILED_ATTEMPTS,
                .on_data = callback,
                .on_polling_end = terminated_callback,
                .on_error = NULL,
        };

        return usb_device_auto_polling(dev, pipe_index, &auto_polling,
           request_size, arg);
}

/** Start automatic device polling over interrupt in pipe.
 *
 * The polling settings is copied thus it is okay to destroy the structure
 * after this function returns.
 *
 * @warning There is no guarantee when the request to the device
 * will be sent for the first time (it is possible that this
 * first request would be executed prior to return from this function).
 *
 * @param dev Device to be periodically polled.
 * @param pipe_index Index of the endpoint pipe used for polling.
 * @param polling Polling settings.
 * @param request_size How many bytes to ask for in each request.
 * @param arg Custom argument (passed as is to the callbacks).
 * @return Error code.
 * @retval EOK New fibril polling the device was already started.
 */
int usb_device_auto_polling(usb_device_t *dev, size_t pipe_index,
    const usb_device_auto_polling_t *polling,
    size_t request_size, void *arg)
{
        if ((dev == NULL) || (polling == NULL) || (polling->on_data == NULL)) {
                return EBADMEM;
        }

        if (pipe_index >= dev->pipes_count || request_size == 0) {
                return EINVAL;
        }
        if ((dev->pipes[pipe_index].pipe.transfer_type != USB_TRANSFER_INTERRUPT)
            || (dev->pipes[pipe_index].pipe.direction != USB_DIRECTION_IN)) {
                return EINVAL;
        }

        polling_data_t *polling_data = malloc(sizeof(polling_data_t));
        if (polling_data == NULL) {
                return ENOMEM;
        }

        /* Fill-in the data. */
        polling_data->buffer = malloc(sizeof(request_size));
        if (polling_data->buffer == NULL) {
                free(polling_data);
                return ENOMEM;
        }
        polling_data->request_size = request_size;
        polling_data->dev = dev;
        polling_data->pipe_index = pipe_index;
        polling_data->custom_arg = arg;

        /* Copy provided settings. */
        polling_data->auto_polling = *polling;

        /* Negative value means use descriptor provided value. */
        if (polling->delay < 0) {
                polling_data->auto_polling.delay =
                    (int) dev->pipes[pipe_index].descriptor->poll_interval;
        }

        fid_t fibril = fibril_create(polling_fibril, polling_data);
        if (fibril == 0) {
                free(polling_data->buffer);
                free(polling_data);
                return ENOMEM;
        }
        fibril_add_ready(fibril);

        /* Fibril launched. That fibril will free the allocated data. */

        return EOK;
}

/**
 * @}
 */