root/drivers/isdn/mISDN/dsp_pipeline.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * dsp_pipeline.c: pipelined audio processing
 *
 * Copyright (C) 2007, Nadi Sarrar
 *
 * Nadi Sarrar <nadi@beronet.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/mISDNif.h>
#include <linux/mISDNdsp.h>
#include <linux/export.h>
#include "dsp.h"
#include "dsp_hwec.h"

struct dsp_pipeline_entry {
        struct mISDN_dsp_element *elem;
        void                *p;
        struct list_head     list;
};
struct dsp_element_entry {
        struct mISDN_dsp_element *elem;
        struct device        dev;
        struct list_head     list;
};

static LIST_HEAD(dsp_elements);

/* sysfs */
static const struct class elements_class = {
        .name = "dsp_pipeline",
};

static ssize_t
attr_show_args(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct mISDN_dsp_element *elem = dev_get_drvdata(dev);
        int i;
        char *p = buf;

        *buf = 0;
        for (i = 0; i < elem->num_args; i++)
                p += sprintf(p, "Name:        %s\n%s%s%sDescription: %s\n\n",
                             elem->args[i].name,
                             elem->args[i].def ? "Default:     " : "",
                             elem->args[i].def ? elem->args[i].def : "",
                             elem->args[i].def ? "\n" : "",
                             elem->args[i].desc);

        return p - buf;
}

static struct device_attribute element_attributes[] = {
        __ATTR(args, 0444, attr_show_args, NULL),
};

static void
mISDN_dsp_dev_release(struct device *dev)
{
        struct dsp_element_entry *entry =
                container_of(dev, struct dsp_element_entry, dev);
        list_del(&entry->list);
        kfree(entry);
}

int mISDN_dsp_element_register(struct mISDN_dsp_element *elem)
{
        struct dsp_element_entry *entry;
        int ret, i;

        if (!elem)
                return -EINVAL;

        entry = kzalloc_obj(struct dsp_element_entry, GFP_ATOMIC);
        if (!entry)
                return -ENOMEM;

        INIT_LIST_HEAD(&entry->list);
        entry->elem = elem;

        entry->dev.class = &elements_class;
        entry->dev.release = mISDN_dsp_dev_release;
        dev_set_drvdata(&entry->dev, elem);
        dev_set_name(&entry->dev, "%s", elem->name);
        ret = device_register(&entry->dev);
        if (ret) {
                printk(KERN_ERR "%s: failed to register %s\n",
                       __func__, elem->name);
                goto err1;
        }
        list_add_tail(&entry->list, &dsp_elements);

        for (i = 0; i < ARRAY_SIZE(element_attributes); ++i) {
                ret = device_create_file(&entry->dev,
                                         &element_attributes[i]);
                if (ret) {
                        printk(KERN_ERR "%s: failed to create device file\n",
                               __func__);
                        goto err2;
                }
        }

        return 0;

err2:
        device_unregister(&entry->dev);
        return ret;
err1:
        put_device(&entry->dev);
        return ret;
}
EXPORT_SYMBOL(mISDN_dsp_element_register);

void mISDN_dsp_element_unregister(struct mISDN_dsp_element *elem)
{
        struct dsp_element_entry *entry, *n;

        if (!elem)
                return;

        list_for_each_entry_safe(entry, n, &dsp_elements, list)
                if (entry->elem == elem) {
                        device_unregister(&entry->dev);
                        return;
                }
        printk(KERN_ERR "%s: element %s not in list.\n", __func__, elem->name);
}
EXPORT_SYMBOL(mISDN_dsp_element_unregister);

int dsp_pipeline_module_init(void)
{
        int err;

        err = class_register(&elements_class);
        if (err)
                return err;

        dsp_hwec_init();

        return 0;
}

void dsp_pipeline_module_exit(void)
{
        struct dsp_element_entry *entry, *n;

        dsp_hwec_exit();

        class_unregister(&elements_class);

        list_for_each_entry_safe(entry, n, &dsp_elements, list) {
                list_del(&entry->list);
                printk(KERN_WARNING "%s: element was still registered: %s\n",
                       __func__, entry->elem->name);
                kfree(entry);
        }
}

int dsp_pipeline_init(struct dsp_pipeline *pipeline)
{
        if (!pipeline)
                return -EINVAL;

        INIT_LIST_HEAD(&pipeline->list);

        return 0;
}

static inline void _dsp_pipeline_destroy(struct dsp_pipeline *pipeline)
{
        struct dsp_pipeline_entry *entry, *n;

        list_for_each_entry_safe(entry, n, &pipeline->list, list) {
                list_del(&entry->list);
                if (entry->elem == dsp_hwec)
                        dsp_hwec_disable(container_of(pipeline, struct dsp,
                                                      pipeline));
                else
                        entry->elem->free(entry->p);
                kfree(entry);
        }
}

void dsp_pipeline_destroy(struct dsp_pipeline *pipeline)
{

        if (!pipeline)
                return;

        _dsp_pipeline_destroy(pipeline);
}

int dsp_pipeline_build(struct dsp_pipeline *pipeline, const char *cfg)
{
        int found = 0;
        char *dup, *next, *tok, *name, *args;
        struct dsp_element_entry *entry, *n;
        struct dsp_pipeline_entry *pipeline_entry;
        struct mISDN_dsp_element *elem;

        if (!pipeline)
                return -EINVAL;

        if (!list_empty(&pipeline->list))
                _dsp_pipeline_destroy(pipeline);

        dup = next = kstrdup(cfg, GFP_ATOMIC);
        if (!dup)
                return 0;
        while ((tok = strsep(&next, "|"))) {
                if (!strlen(tok))
                        continue;
                name = strsep(&tok, "(");
                args = strsep(&tok, ")");
                if (args && !*args)
                        args = NULL;

                list_for_each_entry_safe(entry, n, &dsp_elements, list)
                        if (!strcmp(entry->elem->name, name)) {
                                elem = entry->elem;

                                pipeline_entry = kmalloc_obj(struct dsp_pipeline_entry,
                                                             GFP_ATOMIC);
                                if (!pipeline_entry) {
                                        printk(KERN_ERR "%s: failed to add "
                                               "entry to pipeline: %s (out of "
                                               "memory)\n", __func__, elem->name);
                                        goto _out;
                                }
                                pipeline_entry->elem = elem;

                                if (elem == dsp_hwec) {
                                        /* This is a hack to make the hwec
                                           available as a pipeline module */
                                        dsp_hwec_enable(container_of(pipeline,
                                                                     struct dsp, pipeline), args);
                                        list_add_tail(&pipeline_entry->list,
                                                      &pipeline->list);
                                } else {
                                        pipeline_entry->p = elem->new(args);
                                        if (pipeline_entry->p) {
                                                list_add_tail(&pipeline_entry->
                                                              list, &pipeline->list);
                                        } else {
                                                printk(KERN_ERR "%s: failed "
                                                       "to add entry to pipeline: "
                                                       "%s (new() returned NULL)\n",
                                                       __func__, elem->name);
                                                kfree(pipeline_entry);
                                        }
                                }
                                found = 1;
                                break;
                        }

                if (found)
                        found = 0;
                else
                        printk(KERN_ERR "%s: element not found, skipping: "
                               "%s\n", __func__, name);
        }

_out:
        if (!list_empty(&pipeline->list))
                pipeline->inuse = 1;
        else
                pipeline->inuse = 0;

        kfree(dup);
        return 0;
}

void dsp_pipeline_process_tx(struct dsp_pipeline *pipeline, u8 *data, int len)
{
        struct dsp_pipeline_entry *entry;

        if (!pipeline)
                return;

        list_for_each_entry(entry, &pipeline->list, list)
                if (entry->elem->process_tx)
                        entry->elem->process_tx(entry->p, data, len);
}

void dsp_pipeline_process_rx(struct dsp_pipeline *pipeline, u8 *data, int len,
                             unsigned int txlen)
{
        struct dsp_pipeline_entry *entry;

        if (!pipeline)
                return;

        list_for_each_entry_reverse(entry, &pipeline->list, list)
                if (entry->elem->process_rx)
                        entry->elem->process_rx(entry->p, data, len, txlen);
}