HelenOS sources

root/uspace/srv/hid/output/port/chardev.c

DEFINITIONS

1. chardev_flush
2. chardev_putchar
3. chardev_putuchar
4. chardev_control_puts
5. find_output_dev
6. check_for_dev
7. chardev_init

/*
 * Copyright (c) 2024 Jiri Svoboda
 * Copyright (c) 2016 Jakub Jermar
 * 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.
 */

/** @addtogropu output
 * @{
 */

#include <async.h>
#include <config.h>
#include <errno.h>
#include <fibril_synch.h>
#include <io/chardev.h>
#include <loc.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include "../ctl/serial.h"
#include "../output.h"
#include "chardev.h"

enum {
        chardev_buf_size = 4096
};

static char *console;

static async_sess_t *sess;
static chardev_t *chardev;
static service_id_t serial_cat_id;
static service_id_t console_cat_id;

static uint8_t chardev_buf[chardev_buf_size];
static size_t chardev_bused;

static FIBRIL_MUTEX_INITIALIZE(discovery_lock);
static bool discovery_finished;
static FIBRIL_CONDVAR_INITIALIZE(discovery_cv);

static void chardev_flush(void)
{
        size_t nwr;

        if (chardev_bused == 0)
                return;

        chardev_write(chardev, chardev_buf, chardev_bused, &nwr);
        /* XXX Handle error */

        chardev_bused = 0;
}

static void chardev_putchar(char ch)
{
        if (chardev_bused == chardev_buf_size)
                chardev_flush();
        chardev_buf[chardev_bused++] = (uint8_t) ch;
}

static void chardev_putuchar(char32_t ch)
{
        char buf[STR_BOUNDS(1)];
        size_t off;
        size_t i;
        errno_t rc;

        off = 0;
        rc = chr_encode(ch, buf, &off, sizeof(buf));
        if (rc != EOK)
                return;

        for (i = 0; i < off; i++)
                chardev_putchar(buf[i]);
}

static void chardev_control_puts(const char *str)
{
        const char *p;

        p = str;
        while (*p != '\0')
                chardev_putuchar(*p++);
}

static bool find_output_dev(service_id_t *svcid)
{
        service_id_t *svc;
        size_t svcs;
        errno_t rc;

        rc = loc_category_get_svcs(serial_cat_id, &svc, &svcs);
        if (rc != EOK) {
                fibril_mutex_unlock(&discovery_lock);
                printf("%s: Failed to get services\n", NAME);
                return false;
        }

        for (size_t i = 0; i < svcs; i++) {
                char *name;

                rc = loc_service_get_name(svc[i], &name);
                if (rc != EOK)
                        continue;

                if (!str_cmp(console, name)) {
                        /*
                         * This is the serial console service that the user
                         * wanted to use.
                         */
                        *svcid = svc[i];
                        free(svc);
                        return true;
                }

                free(name);
        }

        free(svc);

        /* Look for any service in the 'console' category */

        rc = loc_category_get_svcs(console_cat_id, &svc, &svcs);
        if (rc != EOK) {
                fibril_mutex_unlock(&discovery_lock);
                printf("%s: Failed to get services\n", NAME);
                return false;
        }

        if (svcs > 0) {
                *svcid = svc[0];
                free(svc);
                return true;
        }

        free(svc);
        return false;
}

/*
 * This callback scans all the services in the 'serial' category, hoping to see
 * the single one the user wishes to use as a serial console. If it spots it, it
 * connects to it and registers it as an output device. Then it unblocks the
 * fibril blocked in chardev_init().
 */
static void check_for_dev(void *arg)
{
        errno_t rc;
        bool found;
        service_id_t sid;

        fibril_mutex_lock(&discovery_lock);
        if (discovery_finished) {
                // TODO: no need to receive these callbacks anymore
                fibril_mutex_unlock(&discovery_lock);
                return;
        }

        found = find_output_dev(&sid);
        if (!found) {
                fibril_mutex_unlock(&discovery_lock);
                return;
        }

        printf("%s: Connecting service %zu\n", NAME, sid);
        char *name;
        rc = loc_service_get_name(sid, &name);
        if (rc != EOK) {
                fibril_mutex_unlock(&discovery_lock);
                return;
        }
        printf("%s: Service name is %s\n", NAME, name);
        free(name);

        sess = loc_service_connect(sid, INTERFACE_DDF, IPC_FLAG_BLOCKING);
        if (!sess) {
                fibril_mutex_unlock(&discovery_lock);
                printf("%s: Failed connecting to device\n", NAME);
                return;
        }

        rc = chardev_open(sess, &chardev);
        if (rc != EOK) {
                fibril_mutex_unlock(&discovery_lock);
                printf("%s: Failed opening character device\n", NAME);
                return;
        }

        serial_init(chardev_putuchar, chardev_control_puts, chardev_flush);

        discovery_finished = true;
        fibril_condvar_signal(&discovery_cv);
        fibril_mutex_unlock(&discovery_lock);
}

errno_t chardev_init(void)
{
        if (!config_key_exists("console")) {
                console = NULL;
#ifdef MACHINE_ski
                /* OK */
#elif defined(UARCH_sparc64) && defined(PROCESSOR_sun4v)
                /* OK */
#elif defined(MACHINE_msim)
                /* OK */
#elif defined(UARCH_arm64) && defined(MACHINE_virt)
                /* OK */
#elif defined(UARCH_arm64) && defined(MACHINE_hikey960)
                /* OK */
#else
                return EOK;
#endif
        } else {
                console = config_get_value("console");
                if (!console)
                        return EOK;
        }

        errno_t rc = loc_category_get_id("serial", &serial_cat_id, IPC_FLAG_BLOCKING);
        if (rc != EOK) {
                printf("%s: Failed to get \"serial\" category ID.\n", NAME);
                return rc;
        }

        rc = loc_category_get_id("console", &console_cat_id, IPC_FLAG_BLOCKING);
        if (rc != EOK) {
                printf("%s: Failed to get \"console\" category ID.\n", NAME);
                return rc;
        }

        rc = loc_register_cat_change_cb(check_for_dev, NULL);
        if (rc != EOK) {
                printf("%s: Failed to register callback for device discovery.\n",
                    NAME);
                return rc;
        }

        check_for_dev(NULL);

        fibril_mutex_lock(&discovery_lock);
        while (!discovery_finished)
                fibril_condvar_wait(&discovery_cv, &discovery_lock);
        fibril_mutex_unlock(&discovery_lock);

        return EOK;
}

/** @}
 */