// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Functions for the OPL4 proc file
 * Copyright (c) 2003 by Clemens Ladisch <clemens@ladisch.de>
 */

#include "opl4_local.h"
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <sound/info.h>

static int snd_opl4_mem_proc_open(struct snd_info_entry *entry,
                                  unsigned short mode, void **file_private_data)
{
        struct snd_opl4 *opl4 = entry->private_data;

        guard(mutex)(&opl4->access_mutex);
        if (opl4->memory_access)
                return -EBUSY;
        opl4->memory_access++;
        return 0;
}

static int snd_opl4_mem_proc_release(struct snd_info_entry *entry,
                                     unsigned short mode, void *file_private_data)
{
        struct snd_opl4 *opl4 = entry->private_data;

        guard(mutex)(&opl4->access_mutex);
        opl4->memory_access--;
        return 0;
}

static ssize_t snd_opl4_mem_proc_read(struct snd_info_entry *entry,
                                      void *file_private_data,
                                      struct file *file, char __user *_buf,
                                      size_t count, loff_t pos)
{
        struct snd_opl4 *opl4 = entry->private_data;
        char* buf;

        buf = vmalloc(count);
        if (!buf)
                return -ENOMEM;
        snd_opl4_read_memory(opl4, buf, pos, count);
        if (copy_to_user(_buf, buf, count)) {
                vfree(buf);
                return -EFAULT;
        }
        vfree(buf);
        return count;
}

static ssize_t snd_opl4_mem_proc_write(struct snd_info_entry *entry,
                                       void *file_private_data,
                                       struct file *file,
                                       const char __user *_buf,
                                       size_t count, loff_t pos)
{
        struct snd_opl4 *opl4 = entry->private_data;
        char *buf;

        buf = vmalloc(count);
        if (!buf)
                return -ENOMEM;
        if (copy_from_user(buf, _buf, count)) {
                vfree(buf);
                return -EFAULT;
        }
        snd_opl4_write_memory(opl4, buf, pos, count);
        vfree(buf);
        return count;
}

static const struct snd_info_entry_ops snd_opl4_mem_proc_ops = {
        .open = snd_opl4_mem_proc_open,
        .release = snd_opl4_mem_proc_release,
        .read = snd_opl4_mem_proc_read,
        .write = snd_opl4_mem_proc_write,
};

int snd_opl4_create_proc(struct snd_opl4 *opl4)
{
        struct snd_info_entry *entry;

        entry = snd_info_create_card_entry(opl4->card, "opl4-mem", opl4->card->proc_root);
        if (entry) {
                if (opl4->hardware < OPL3_HW_OPL4_ML) {
                        /* OPL4 can access 4 MB external ROM/SRAM */
                        entry->mode |= 0200;
                        entry->size = 4 * 1024 * 1024;
                } else {
                        /* OPL4-ML has 1 MB internal ROM */
                        entry->size = 1 * 1024 * 1024;
                }
                entry->content = SNDRV_INFO_CONTENT_DATA;
                entry->c.ops = &snd_opl4_mem_proc_ops;
                entry->module = THIS_MODULE;
                entry->private_data = opl4;
        }
        opl4->proc_entry = entry;
        return 0;
}

void snd_opl4_free_proc(struct snd_opl4 *opl4)
{
        snd_info_free_entry(opl4->proc_entry);
}