source: mainline/uspace/drv/bus/isa/isa.c

/*
 * Copyright (c) 2025 Jiri Svoboda
 * Copyright (c) 2010 Lenka Trochtova
 * Copyright (c) 2011 Jan Vesely
 * 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 isa
 * @{
 */

/** @file
 */

#include <adt/list.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <stdbool.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include <str.h>
#include <str_error.h>
#include <ctype.h>
#include <macros.h>
#include <stdlib.h>
#include <dirent.h>
#include <ipc/irc.h>
#include <ipc/services.h>
#include <vfs/vfs.h>
#include <irc.h>
#include <ns.h>

#include <ddf/driver.h>
#include <ddf/log.h>
#include <ops/hw_res.h>
#include <ops/pio_window.h>

#include <device/hw_res.h>
#include <device/pio_window.h>

#include <pci_dev_iface.h>

#include "i8237.h"

#define NAME "isa"
#define ISA_CHILD_FUN_CONF_PATH "/drv/isa/isa.dev"
#define EBUS_CHILD_FUN_CONF_PATH "/drv/isa/ebus.dev"

#define ISA_MAX_HW_RES 6

typedef struct {
        fibril_mutex_t mutex;
        bool pci_isa_bridge;
        uint16_t pci_vendor_id;
        uint16_t pci_device_id;
        uint8_t pci_class;
        uint8_t pci_subclass;
        ddf_dev_t *dev;
        ddf_fun_t *fctl;
        pio_window_t pio_win;
        list_t functions;
} isa_bus_t;

typedef struct isa_fun {
        fibril_mutex_t mutex;
        ddf_fun_t *fnode;
        hw_resource_t resources[ISA_MAX_HW_RES];
        hw_resource_list_t hw_resources;
        link_t bus_link;
        isa_bus_t *bus;
} isa_fun_t;

/** Obtain soft-state from device node */
static isa_bus_t *isa_bus(ddf_dev_t *dev)
{
        return ddf_dev_data_get(dev);
}

/** Obtain soft-state from function node */
static isa_fun_t *isa_fun(ddf_fun_t *fun)
{
        return ddf_fun_data_get(fun);
}

static hw_resource_list_t *isa_fun_get_resources(ddf_fun_t *fnode)
{
        isa_fun_t *fun = isa_fun(fnode);
        assert(fun);

        return &fun->hw_resources;
}

static bool isa_fun_owns_interrupt(isa_fun_t *fun, int irq)
{
        const hw_resource_list_t *res = &fun->hw_resources;

        /* Check that specified irq really belongs to the function */
        for (size_t i = 0; i < res->count; ++i) {
                if (res->resources[i].type == INTERRUPT &&
                    res->resources[i].res.interrupt.irq == irq) {
                        return true;
                }
        }

        return false;
}

static errno_t isa_fun_enable_interrupt(ddf_fun_t *fnode, int irq)
{
        isa_fun_t *fun = isa_fun(fnode);

        if (!isa_fun_owns_interrupt(fun, irq))
                return EINVAL;

        return irc_enable_interrupt(irq);
}

static errno_t isa_fun_disable_interrupt(ddf_fun_t *fnode, int irq)
{
        isa_fun_t *fun = isa_fun(fnode);

        if (!isa_fun_owns_interrupt(fun, irq))
                return EINVAL;

        return irc_disable_interrupt(irq);
}

static errno_t isa_fun_clear_interrupt(ddf_fun_t *fnode, int irq)
{
        isa_fun_t *fun = isa_fun(fnode);

        if (!isa_fun_owns_interrupt(fun, irq))
                return EINVAL;

        return irc_clear_interrupt(irq);
}

static errno_t isa_fun_setup_dma(ddf_fun_t *fnode,
    unsigned int channel, uint32_t pa, uint32_t size, uint8_t mode)
{
        assert(fnode);
        isa_fun_t *fun = isa_fun(fnode);
        assert(fun);
        const hw_resource_list_t *res = &fun->hw_resources;
        assert(res);

        for (size_t i = 0; i < res->count; ++i) {
                /* Check for assigned channel */
                if (((res->resources[i].type == DMA_CHANNEL_16) &&
                    (res->resources[i].res.dma_channel.dma16 == channel)) ||
                    ((res->resources[i].type == DMA_CHANNEL_8) &&
                    (res->resources[i].res.dma_channel.dma8 == channel))) {
                        return dma_channel_setup(channel, pa, size, mode);
                }
        }

        return EINVAL;
}

static errno_t isa_fun_remain_dma(ddf_fun_t *fnode,
    unsigned channel, size_t *size)
{
        assert(size);
        assert(fnode);
        isa_fun_t *fun = isa_fun(fnode);
        assert(fun);
        const hw_resource_list_t *res = &fun->hw_resources;
        assert(res);

        for (size_t i = 0; i < res->count; ++i) {
                /* Check for assigned channel */
                if (((res->resources[i].type == DMA_CHANNEL_16) &&
                    (res->resources[i].res.dma_channel.dma16 == channel)) ||
                    ((res->resources[i].type == DMA_CHANNEL_8) &&
                    (res->resources[i].res.dma_channel.dma8 == channel))) {
                        return dma_channel_remain(channel, size);
                }
        }

        return EINVAL;
}

/** Handle legacy IO availability query from function.
 *
 * @param fnode Function performing the query
 * @param rclaims Place to store the legacy IO claims bitmask
 * @return EOK on success or an error code
 */
static errno_t isa_fun_query_legacy_io(ddf_fun_t *fnode,
    hw_res_claims_t *rclaims)
{
        isa_fun_t *fun = isa_fun(fnode);
        hw_res_claims_t claims;
        async_sess_t *sess;
        errno_t rc;

        ddf_msg(LVL_DEBUG, "isa_fun_query_legacy_io()");

        sess = ddf_dev_parent_sess_get(fun->bus->dev);
        if (sess == NULL) {
                ddf_msg(LVL_ERROR, "isa_dev_add failed to connect to the "
                    "parent driver.");
                return ENOENT;
        }

        if (!fun->bus->pci_isa_bridge) {
                ddf_msg(LVL_NOTE, "isa_fun_query_legacy_io: classic ISA - "
                    "legacy IDE range is available");
                /* Classic ISA, we can be sure IDE is unclaimed by PCI */
                claims = 0;
        } else {
                ddf_msg(LVL_NOTE, "isa_fun_query_legacy_io: ISA bridge - "
                    "determine legacy IDE availability from PCI bus driver");
                rc = hw_res_query_legacy_io(sess, &claims);
                if (rc != EOK) {
                        ddf_msg(LVL_NOTE, "Error querying legacy IO claims.");
                        return rc;
                }
        }

        ddf_msg(LVL_DEBUG, "isa_fun_query_legacy_io: returning 0x%x", claims);
        *rclaims = claims;
        return EOK;
}

static hw_res_ops_t isa_fun_hw_res_ops = {
        .get_resource_list = isa_fun_get_resources,
        .enable_interrupt = isa_fun_enable_interrupt,
        .disable_interrupt = isa_fun_disable_interrupt,
        .clear_interrupt = isa_fun_clear_interrupt,
        .dma_channel_setup = isa_fun_setup_dma,
        .dma_channel_remain = isa_fun_remain_dma,
        .query_legacy_io = isa_fun_query_legacy_io
};

static pio_window_t *isa_fun_get_pio_window(ddf_fun_t *fnode)
{
        ddf_dev_t *dev = ddf_fun_get_dev(fnode);
        isa_bus_t *isa = isa_bus(dev);
        assert(isa);

        return &isa->pio_win;
}

static pio_window_ops_t isa_fun_pio_window_ops = {
        .get_pio_window = isa_fun_get_pio_window
};

static ddf_dev_ops_t isa_fun_ops = {
        .interfaces[HW_RES_DEV_IFACE] = &isa_fun_hw_res_ops,
        .interfaces[PIO_WINDOW_DEV_IFACE] = &isa_fun_pio_window_ops,
};

static errno_t isa_dev_add(ddf_dev_t *dev);
static errno_t isa_dev_remove(ddf_dev_t *dev);
static errno_t isa_fun_online(ddf_fun_t *fun);
static errno_t isa_fun_offline(ddf_fun_t *fun);

/** The isa device driver's standard operations */
static driver_ops_t isa_ops = {
        .dev_add = &isa_dev_add,
        .dev_remove = &isa_dev_remove,
        .fun_online = &isa_fun_online,
        .fun_offline = &isa_fun_offline
};

/** The isa device driver structure. */
static driver_t isa_driver = {
        .name = NAME,
        .driver_ops = &isa_ops
};

static isa_fun_t *isa_fun_create(isa_bus_t *isa, const char *name)
{
        ddf_fun_t *fnode = ddf_fun_create(isa->dev, fun_inner, name);
        if (fnode == NULL)
                return NULL;

        isa_fun_t *fun = ddf_fun_data_alloc(fnode, sizeof(isa_fun_t));
        if (fun == NULL) {
                ddf_fun_destroy(fnode);
                return NULL;
        }

        fibril_mutex_initialize(&fun->mutex);
        fun->hw_resources.resources = fun->resources;
        fun->bus = isa;

        fun->fnode = fnode;
        return fun;
}

static char *fun_conf_read(const char *conf_path)
{
        bool suc = false;
        char *buf = NULL;
        bool opened = false;
        int fd;
        size_t len;
        errno_t rc;
        size_t nread;
        vfs_stat_t st;

        rc = vfs_lookup_open(conf_path, WALK_REGULAR, MODE_READ, &fd);
        if (rc != EOK) {
                ddf_msg(LVL_ERROR, "Unable to open %s", conf_path);
                goto cleanup;
        }

        opened = true;

        if (vfs_stat(fd, &st) != EOK) {
                ddf_msg(LVL_ERROR, "Unable to vfs_stat %d", fd);
                goto cleanup;
        }

        len = st.size;
        if (len == 0) {
                ddf_msg(LVL_ERROR, "Configuration file '%s' is empty.",
                    conf_path);
                goto cleanup;
        }

        buf = malloc(len + 1);
        if (buf == NULL) {
                ddf_msg(LVL_ERROR, "Memory allocation failed.");
                goto cleanup;
        }

        rc = vfs_read(fd, (aoff64_t []) { 0 }, buf, len, &nread);
        if (rc != EOK) {
                ddf_msg(LVL_ERROR, "Unable to read file '%s'.", conf_path);
                goto cleanup;
        }

        buf[nread] = 0;

        suc = true;

cleanup:
        if (!suc && buf != NULL) {
                free(buf);
                buf = NULL;
        }

        if (opened)
                vfs_put(fd);

        return buf;
}

static char *str_get_line(char *str, char **next)
{
        char *line = str;
        *next = NULL;

        if (str == NULL) {
                return NULL;
        }

        while (*str != '\0' && *str != '\n') {
                str++;
        }

        if (*str != '\0') {
                *next = str + 1;
        }

        *str = '\0';
        return line;
}

static bool line_empty(const char *line)
{
        while (line != NULL && *line != 0) {
                if (!isspace(*line))
                        return false;
                line++;
        }

        return true;
}

static char *get_device_name(char *line)
{
        /* Skip leading spaces. */
        while (*line != '\0' && isspace(*line)) {
                line++;
        }

        /* Get the name part of the rest of the line. */
        str_tok(line, ":", NULL);
        return line;
}

static inline const char *skip_spaces(const char *line)
{
        /* Skip leading spaces. */
        while (*line != '\0' && isspace(*line))
                line++;

        return line;
}

static void isa_fun_add_irq(isa_fun_t *fun, int irq)
{
        size_t count = fun->hw_resources.count;
        hw_resource_t *resources = fun->hw_resources.resources;

        if (count < ISA_MAX_HW_RES) {
                resources[count].type = INTERRUPT;
                resources[count].res.interrupt.irq = irq;

                fun->hw_resources.count++;

                ddf_msg(LVL_NOTE, "Added irq 0x%x to function %s", irq,
                    ddf_fun_get_name(fun->fnode));
        }
}

static void isa_fun_add_dma(isa_fun_t *fun, int dma)
{
        size_t count = fun->hw_resources.count;
        hw_resource_t *resources = fun->hw_resources.resources;

        if (count < ISA_MAX_HW_RES) {
                if ((dma > 0) && (dma < 4)) {
                        resources[count].type = DMA_CHANNEL_8;
                        resources[count].res.dma_channel.dma8 = dma;

                        fun->hw_resources.count++;
                        ddf_msg(LVL_NOTE, "Added dma 0x%x to function %s", dma,
                            ddf_fun_get_name(fun->fnode));

                        return;
                }

                if ((dma > 4) && (dma < 8)) {
                        resources[count].type = DMA_CHANNEL_16;
                        resources[count].res.dma_channel.dma16 = dma;

                        fun->hw_resources.count++;
                        ddf_msg(LVL_NOTE, "Added dma 0x%x to function %s", dma,
                            ddf_fun_get_name(fun->fnode));

                        return;
                }

                ddf_msg(LVL_WARN, "Skipped dma 0x%x for function %s", dma,
                    ddf_fun_get_name(fun->fnode));
        }
}

static void isa_fun_add_io_range(isa_fun_t *fun, size_t addr, size_t len)
{
        size_t count = fun->hw_resources.count;
        hw_resource_t *resources = fun->hw_resources.resources;

        isa_bus_t *isa = isa_bus(ddf_fun_get_dev(fun->fnode));

        if (count < ISA_MAX_HW_RES) {
                resources[count].type = IO_RANGE;
                resources[count].res.io_range.address = addr;
                resources[count].res.io_range.address += isa->pio_win.io.base;
                resources[count].res.io_range.size = len;
                resources[count].res.io_range.relative = false;
                resources[count].res.io_range.endianness = LITTLE_ENDIAN;

                fun->hw_resources.count++;

                ddf_msg(LVL_NOTE, "Added io range (addr=0x%x, size=0x%x) to "
                    "function %s", (unsigned int) addr, (unsigned int) len,
                    ddf_fun_get_name(fun->fnode));
        }
}

static void isa_fun_add_mem_range(isa_fun_t *fun, uintptr_t addr, size_t len)
{
        size_t count = fun->hw_resources.count;
        hw_resource_t *resources = fun->hw_resources.resources;

        isa_bus_t *isa = isa_bus(ddf_fun_get_dev(fun->fnode));

        if (count < ISA_MAX_HW_RES) {
                resources[count].type = MEM_RANGE;
                resources[count].res.mem_range.address = addr;
                resources[count].res.mem_range.address += isa->pio_win.mem.base;
                resources[count].res.mem_range.size = len;
                resources[count].res.mem_range.relative = false;
                resources[count].res.mem_range.endianness = LITTLE_ENDIAN;

                fun->hw_resources.count++;

                ddf_msg(LVL_NOTE, "Added mem range (addr=0x%zx, size=0x%x) to "
                    "function %s", (uintptr_t) addr, (unsigned int) len,
                    ddf_fun_get_name(fun->fnode));
        }
}

static void fun_parse_irq(isa_fun_t *fun, const char *val)
{
        int irq = 0;
        char *end = NULL;

        val = skip_spaces(val);
        irq = (int) strtol(val, &end, 10);

        if (val != end)
                isa_fun_add_irq(fun, irq);
}

static void fun_parse_dma(isa_fun_t *fun, const char *val)
{
        char *end = NULL;

        val = skip_spaces(val);
        const int dma = strtol(val, &end, 10);

        if (val != end)
                isa_fun_add_dma(fun, dma);
}

static void fun_parse_io_range(isa_fun_t *fun, const char *val)
{
        size_t addr, len;
        char *end = NULL;

        val = skip_spaces(val);
        addr = strtol(val, &end, 0x10);

        if (val == end)
                return;

        val = skip_spaces(end);
        len = strtol(val, &end, 0x10);

        if (val == end)
                return;

        isa_fun_add_io_range(fun, addr, len);
}

static void fun_parse_mem_range(isa_fun_t *fun, const char *val)
{
        uintptr_t addr;
        size_t len;
        char *end = NULL;

        val = skip_spaces(val);
        addr = strtoul(val, &end, 0x10);

        if (val == end)
                return;

        val = skip_spaces(end);
        len = strtol(val, &end, 0x10);

        if (val == end)
                return;

        isa_fun_add_mem_range(fun, addr, len);
}

static void get_match_id(char **id, const char *val)
{
        const char *end = val;

        while (!isspace(*end))
                end++;

        size_t size = end - val + 1;
        *id = (char *)malloc(size);
        str_cpy(*id, size, val);
}

static void fun_parse_match_id(isa_fun_t *fun, const char *val)
{
        char *id = NULL;
        char *end = NULL;

        val = skip_spaces(val);

        int score = (int)strtol(val, &end, 10);
        if (val == end) {
                ddf_msg(LVL_ERROR, "Cannot read match score for function "
                    "%s.", ddf_fun_get_name(fun->fnode));
                return;
        }

        val = skip_spaces(end);
        get_match_id(&id, val);
        if (id == NULL) {
                ddf_msg(LVL_ERROR, "Cannot read match ID for function %s.",
                    ddf_fun_get_name(fun->fnode));
                return;
        }

        ddf_msg(LVL_DEBUG, "Adding match id '%s' with score %d to "
            "function %s", id, score, ddf_fun_get_name(fun->fnode));

        errno_t rc = ddf_fun_add_match_id(fun->fnode, id, score);
        if (rc != EOK) {
                ddf_msg(LVL_ERROR, "Failed adding match ID: %s",
                    str_error(rc));
        }

        free(id);
}

static bool prop_parse(isa_fun_t *fun, const char *line, const char *prop,
    void (*read_fn)(isa_fun_t *, const char *))
{
        size_t proplen = str_size(prop);

        if (str_lcmp(line, prop, proplen) == 0) {
                line += proplen;
                line = skip_spaces(line);
                (*read_fn)(fun, line);

                return true;
        }

        return false;
}

static void fun_prop_parse(isa_fun_t *fun, const char *line)
{
        /* Skip leading spaces. */
        line = skip_spaces(line);

        if (!prop_parse(fun, line, "io_range", &fun_parse_io_range) &&
            !prop_parse(fun, line, "mem_range", &fun_parse_mem_range) &&
            !prop_parse(fun, line, "irq", &fun_parse_irq) &&
            !prop_parse(fun, line, "dma", &fun_parse_dma) &&
            !prop_parse(fun, line, "match", &fun_parse_match_id)) {

                ddf_msg(LVL_ERROR, "Undefined device property at line '%s'",
                    line);
        }
}

static char *isa_fun_read_info(char *fun_conf, isa_bus_t *isa)
{
        char *line;

        /* Skip empty lines. */
        do {
                line = str_get_line(fun_conf, &fun_conf);

                if (line == NULL) {
                        /* no more lines */
                        return NULL;
                }

        } while (line_empty(line));

        /* Get device name. */
        const char *fun_name = get_device_name(line);
        if (fun_name == NULL)
                return NULL;

        isa_fun_t *fun = isa_fun_create(isa, fun_name);
        if (fun == NULL) {
                return NULL;
        }

        /* Get properties of the device (match ids, irq and io range). */
        while (true) {
                line = str_get_line(fun_conf, &fun_conf);

                if (line_empty(line)) {
                        /* no more device properties */
                        break;
                }

                /*
                 * Get the device's property from the configuration line
                 * and store it in the device structure.
                 */
                fun_prop_parse(fun, line);
        }

        /* Set device operations to the device. */
        ddf_fun_set_ops(fun->fnode, &isa_fun_ops);

        ddf_msg(LVL_DEBUG, "Binding function %s.", ddf_fun_get_name(fun->fnode));

        /* XXX Handle error */
        (void) ddf_fun_bind(fun->fnode);

        list_append(&fun->bus_link, &isa->functions);

        return fun_conf;
}

static void isa_functions_add(isa_bus_t *isa)
{
#define BASE_CLASS_BRIDGE       0x06
#define SUB_CLASS_BRIDGE_ISA    0x01
        bool isa_bridge = ((isa->pci_class == BASE_CLASS_BRIDGE) &&
            (isa->pci_subclass == SUB_CLASS_BRIDGE_ISA));

#define VENDOR_ID_SUN   0x108e
#define DEVICE_ID_EBUS  0x1000
        bool ebus = ((isa->pci_vendor_id == VENDOR_ID_SUN) &&
            (isa->pci_device_id == DEVICE_ID_EBUS));

        const char *conf_path = NULL;
        if (isa_bridge)
                conf_path = ISA_CHILD_FUN_CONF_PATH;
        else if (ebus)
                conf_path = EBUS_CHILD_FUN_CONF_PATH;

        char *conf = fun_conf_read(conf_path);
        while (conf != NULL && *conf != '\0') {
                conf = isa_fun_read_info(conf, isa);
        }
        free(conf);
}

static errno_t isa_read_pci_cfg(isa_bus_t *isa, async_sess_t *sess)
{
        errno_t rc;

        rc = pci_config_space_read_16(sess, PCI_VENDOR_ID, &isa->pci_vendor_id);
        if (rc != EOK)
                return rc;
        rc = pci_config_space_read_16(sess, PCI_DEVICE_ID, &isa->pci_device_id);
        if (rc != EOK)
                return rc;
        rc = pci_config_space_read_8(sess, PCI_BASE_CLASS, &isa->pci_class);
        if (rc != EOK)
                return rc;
        rc = pci_config_space_read_8(sess, PCI_SUB_CLASS, &isa->pci_subclass);
        if (rc != EOK)
                return rc;

        return EOK;
}

static errno_t isa_dev_add(ddf_dev_t *dev)
{
        async_sess_t *sess;
        errno_t rc;

        ddf_msg(LVL_DEBUG, "isa_dev_add, device handle = %d",
            (int) ddf_dev_get_handle(dev));

        isa_bus_t *isa = ddf_dev_data_alloc(dev, sizeof(isa_bus_t));
        if (isa == NULL)
                return ENOMEM;

        fibril_mutex_initialize(&isa->mutex);
        isa->dev = dev;
        list_initialize(&isa->functions);

        sess = ddf_dev_parent_sess_get(dev);
        if (sess == NULL) {
                ddf_msg(LVL_ERROR, "isa_dev_add failed to connect to the "
                    "parent driver.");
                return ENOENT;
        }

        rc = isa_read_pci_cfg(isa, sess);
        if (rc != EOK) {
                ddf_msg(LVL_NOTE, "Cannot read PCI config. Assuming ISA classic.");
                isa->pci_isa_bridge = false;
                isa->pci_vendor_id = 0;
                isa->pci_device_id = 0;
                isa->pci_class = BASE_CLASS_BRIDGE;
                isa->pci_subclass = SUB_CLASS_BRIDGE_ISA;
        } else {
                ddf_msg(LVL_NOTE, "ISA Bridge");
                isa->pci_isa_bridge = true;
        }

        rc = pio_window_get(sess, &isa->pio_win);
        if (rc != EOK) {
                ddf_msg(LVL_ERROR, "isa_dev_add failed to get PIO window "
                    "for the device.");
                return rc;
        }

        /* Make the bus device more visible. Does not do anything. */
        ddf_msg(LVL_DEBUG, "Adding a 'ctl' function");

        fibril_mutex_lock(&isa->mutex);

        isa->fctl = ddf_fun_create(dev, fun_exposed, "ctl");
        if (isa->fctl == NULL) {
                ddf_msg(LVL_ERROR, "Failed creating control function.");
                return EXDEV;
        }

        if (ddf_fun_bind(isa->fctl) != EOK) {
                ddf_fun_destroy(isa->fctl);
                ddf_msg(LVL_ERROR, "Failed binding control function.");
                return EXDEV;
        }

        /* Add functions as specified in the configuration file. */
        isa_functions_add(isa);
        ddf_msg(LVL_NOTE, "Finished enumerating legacy functions");

        fibril_mutex_unlock(&isa->mutex);

        return EOK;
}

static errno_t isa_dev_remove(ddf_dev_t *dev)
{
        isa_bus_t *isa = isa_bus(dev);

        fibril_mutex_lock(&isa->mutex);

        while (!list_empty(&isa->functions)) {
                isa_fun_t *fun = list_get_instance(list_first(&isa->functions),
                    isa_fun_t, bus_link);

                errno_t rc = ddf_fun_offline(fun->fnode);
                if (rc != EOK) {
                        fibril_mutex_unlock(&isa->mutex);
                        ddf_msg(LVL_ERROR, "Failed offlining %s", ddf_fun_get_name(fun->fnode));
                        return rc;
                }

                rc = ddf_fun_unbind(fun->fnode);
                if (rc != EOK) {
                        fibril_mutex_unlock(&isa->mutex);
                        ddf_msg(LVL_ERROR, "Failed unbinding %s", ddf_fun_get_name(fun->fnode));
                        return rc;
                }

                list_remove(&fun->bus_link);

                ddf_fun_destroy(fun->fnode);
        }

        if (ddf_fun_unbind(isa->fctl) != EOK) {
                fibril_mutex_unlock(&isa->mutex);
                ddf_msg(LVL_ERROR, "Failed unbinding control function.");
                return EXDEV;
        }

        fibril_mutex_unlock(&isa->mutex);

        return EOK;
}

static errno_t isa_fun_online(ddf_fun_t *fun)
{
        ddf_msg(LVL_DEBUG, "isa_fun_online()");
        return ddf_fun_online(fun);
}

static errno_t isa_fun_offline(ddf_fun_t *fun)
{
        ddf_msg(LVL_DEBUG, "isa_fun_offline()");
        return ddf_fun_offline(fun);
}

int main(int argc, char *argv[])
{
        printf(NAME ": HelenOS ISA bus driver\n");
        ddf_log_init(NAME);
        return ddf_driver_main(&isa_driver);
}

/**
 * @}
 */