linux/arch/um/drivers/hostaudio_kern.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2002 Steve Schmidtke
   4 */
   5
   6#include <linux/fs.h>
   7#include <linux/module.h>
   8#include <linux/slab.h>
   9#include <linux/sound.h>
  10#include <linux/soundcard.h>
  11#include <linux/mutex.h>
  12#include <linux/uaccess.h>
  13#include <init.h>
  14#include <os.h>
  15
  16struct hostaudio_state {
  17        int fd;
  18};
  19
  20struct hostmixer_state {
  21        int fd;
  22};
  23
  24#define HOSTAUDIO_DEV_DSP "/dev/sound/dsp"
  25#define HOSTAUDIO_DEV_MIXER "/dev/sound/mixer"
  26
  27/*
  28 * Changed either at boot time or module load time.  At boot, this is
  29 * single-threaded; at module load, multiple modules would each have
  30 * their own copy of these variables.
  31 */
  32static char *dsp = HOSTAUDIO_DEV_DSP;
  33static char *mixer = HOSTAUDIO_DEV_MIXER;
  34
  35#define DSP_HELP \
  36"    This is used to specify the host dsp device to the hostaudio driver.\n" \
  37"    The default is \"" HOSTAUDIO_DEV_DSP "\".\n\n"
  38
  39#define MIXER_HELP \
  40"    This is used to specify the host mixer device to the hostaudio driver.\n"\
  41"    The default is \"" HOSTAUDIO_DEV_MIXER "\".\n\n"
  42
  43module_param(dsp, charp, 0644);
  44MODULE_PARM_DESC(dsp, DSP_HELP);
  45module_param(mixer, charp, 0644);
  46MODULE_PARM_DESC(mixer, MIXER_HELP);
  47
  48#ifndef MODULE
  49static int set_dsp(char *name, int *add)
  50{
  51        dsp = name;
  52        return 0;
  53}
  54
  55__uml_setup("dsp=", set_dsp, "dsp=<dsp device>\n" DSP_HELP);
  56
  57static int set_mixer(char *name, int *add)
  58{
  59        mixer = name;
  60        return 0;
  61}
  62
  63__uml_setup("mixer=", set_mixer, "mixer=<mixer device>\n" MIXER_HELP);
  64#endif
  65
  66static DEFINE_MUTEX(hostaudio_mutex);
  67
  68/* /dev/dsp file operations */
  69
  70static ssize_t hostaudio_read(struct file *file, char __user *buffer,
  71                              size_t count, loff_t *ppos)
  72{
  73        struct hostaudio_state *state = file->private_data;
  74        void *kbuf;
  75        int err;
  76
  77#ifdef DEBUG
  78        printk(KERN_DEBUG "hostaudio: read called, count = %d\n", count);
  79#endif
  80
  81        kbuf = kmalloc(count, GFP_KERNEL);
  82        if (kbuf == NULL)
  83                return -ENOMEM;
  84
  85        err = os_read_file(state->fd, kbuf, count);
  86        if (err < 0)
  87                goto out;
  88
  89        if (copy_to_user(buffer, kbuf, err))
  90                err = -EFAULT;
  91
  92out:
  93        kfree(kbuf);
  94        return err;
  95}
  96
  97static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
  98                               size_t count, loff_t *ppos)
  99{
 100        struct hostaudio_state *state = file->private_data;
 101        void *kbuf;
 102        int err;
 103
 104#ifdef DEBUG
 105        printk(KERN_DEBUG "hostaudio: write called, count = %d\n", count);
 106#endif
 107
 108        kbuf = memdup_user(buffer, count);
 109        if (IS_ERR(kbuf))
 110                return PTR_ERR(kbuf);
 111
 112        err = os_write_file(state->fd, kbuf, count);
 113        if (err < 0)
 114                goto out;
 115        *ppos += err;
 116
 117 out:
 118        kfree(kbuf);
 119        return err;
 120}
 121
 122static __poll_t hostaudio_poll(struct file *file,
 123                                struct poll_table_struct *wait)
 124{
 125#ifdef DEBUG
 126        printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
 127#endif
 128
 129        return 0;
 130}
 131
 132static long hostaudio_ioctl(struct file *file,
 133                           unsigned int cmd, unsigned long arg)
 134{
 135        struct hostaudio_state *state = file->private_data;
 136        unsigned long data = 0;
 137        int err;
 138
 139#ifdef DEBUG
 140        printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
 141#endif
 142        switch(cmd){
 143        case SNDCTL_DSP_SPEED:
 144        case SNDCTL_DSP_STEREO:
 145        case SNDCTL_DSP_GETBLKSIZE:
 146        case SNDCTL_DSP_CHANNELS:
 147        case SNDCTL_DSP_SUBDIVIDE:
 148        case SNDCTL_DSP_SETFRAGMENT:
 149                if (get_user(data, (int __user *) arg))
 150                        return -EFAULT;
 151                break;
 152        default:
 153                break;
 154        }
 155
 156        err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
 157
 158        switch(cmd){
 159        case SNDCTL_DSP_SPEED:
 160        case SNDCTL_DSP_STEREO:
 161        case SNDCTL_DSP_GETBLKSIZE:
 162        case SNDCTL_DSP_CHANNELS:
 163        case SNDCTL_DSP_SUBDIVIDE:
 164        case SNDCTL_DSP_SETFRAGMENT:
 165                if (put_user(data, (int __user *) arg))
 166                        return -EFAULT;
 167                break;
 168        default:
 169                break;
 170        }
 171
 172        return err;
 173}
 174
 175static int hostaudio_open(struct inode *inode, struct file *file)
 176{
 177        struct hostaudio_state *state;
 178        int r = 0, w = 0;
 179        int ret;
 180
 181#ifdef DEBUG
 182        kernel_param_lock(THIS_MODULE);
 183        printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
 184        kernel_param_unlock(THIS_MODULE);
 185#endif
 186
 187        state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
 188        if (state == NULL)
 189                return -ENOMEM;
 190
 191        if (file->f_mode & FMODE_READ)
 192                r = 1;
 193        if (file->f_mode & FMODE_WRITE)
 194                w = 1;
 195
 196        kernel_param_lock(THIS_MODULE);
 197        mutex_lock(&hostaudio_mutex);
 198        ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
 199        mutex_unlock(&hostaudio_mutex);
 200        kernel_param_unlock(THIS_MODULE);
 201
 202        if (ret < 0) {
 203                kfree(state);
 204                return ret;
 205        }
 206        state->fd = ret;
 207        file->private_data = state;
 208        return 0;
 209}
 210
 211static int hostaudio_release(struct inode *inode, struct file *file)
 212{
 213        struct hostaudio_state *state = file->private_data;
 214
 215#ifdef DEBUG
 216        printk(KERN_DEBUG "hostaudio: release called\n");
 217#endif
 218        os_close_file(state->fd);
 219        kfree(state);
 220
 221        return 0;
 222}
 223
 224/* /dev/mixer file operations */
 225
 226static long hostmixer_ioctl_mixdev(struct file *file,
 227                                  unsigned int cmd, unsigned long arg)
 228{
 229        struct hostmixer_state *state = file->private_data;
 230
 231#ifdef DEBUG
 232        printk(KERN_DEBUG "hostmixer: ioctl called\n");
 233#endif
 234
 235        return os_ioctl_generic(state->fd, cmd, arg);
 236}
 237
 238static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
 239{
 240        struct hostmixer_state *state;
 241        int r = 0, w = 0;
 242        int ret;
 243
 244#ifdef DEBUG
 245        printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
 246#endif
 247
 248        state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
 249        if (state == NULL)
 250                return -ENOMEM;
 251
 252        if (file->f_mode & FMODE_READ)
 253                r = 1;
 254        if (file->f_mode & FMODE_WRITE)
 255                w = 1;
 256
 257        kernel_param_lock(THIS_MODULE);
 258        mutex_lock(&hostaudio_mutex);
 259        ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
 260        mutex_unlock(&hostaudio_mutex);
 261        kernel_param_unlock(THIS_MODULE);
 262
 263        if (ret < 0) {
 264                kernel_param_lock(THIS_MODULE);
 265                printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
 266                       "err = %d\n", dsp, -ret);
 267                kernel_param_unlock(THIS_MODULE);
 268                kfree(state);
 269                return ret;
 270        }
 271
 272        file->private_data = state;
 273        return 0;
 274}
 275
 276static int hostmixer_release(struct inode *inode, struct file *file)
 277{
 278        struct hostmixer_state *state = file->private_data;
 279
 280#ifdef DEBUG
 281        printk(KERN_DEBUG "hostmixer: release called\n");
 282#endif
 283
 284        os_close_file(state->fd);
 285        kfree(state);
 286
 287        return 0;
 288}
 289
 290/* kernel module operations */
 291
 292static const struct file_operations hostaudio_fops = {
 293        .owner          = THIS_MODULE,
 294        .llseek         = no_llseek,
 295        .read           = hostaudio_read,
 296        .write          = hostaudio_write,
 297        .poll           = hostaudio_poll,
 298        .unlocked_ioctl = hostaudio_ioctl,
 299        .compat_ioctl   = compat_ptr_ioctl,
 300        .mmap           = NULL,
 301        .open           = hostaudio_open,
 302        .release        = hostaudio_release,
 303};
 304
 305static const struct file_operations hostmixer_fops = {
 306        .owner          = THIS_MODULE,
 307        .llseek         = no_llseek,
 308        .unlocked_ioctl = hostmixer_ioctl_mixdev,
 309        .open           = hostmixer_open_mixdev,
 310        .release        = hostmixer_release,
 311};
 312
 313struct {
 314        int dev_audio;
 315        int dev_mixer;
 316} module_data;
 317
 318MODULE_AUTHOR("Steve Schmidtke");
 319MODULE_DESCRIPTION("UML Audio Relay");
 320MODULE_LICENSE("GPL");
 321
 322static int __init hostaudio_init_module(void)
 323{
 324        kernel_param_lock(THIS_MODULE);
 325        printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
 326               dsp, mixer);
 327        kernel_param_unlock(THIS_MODULE);
 328
 329        module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
 330        if (module_data.dev_audio < 0) {
 331                printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
 332                return -ENODEV;
 333        }
 334
 335        module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
 336        if (module_data.dev_mixer < 0) {
 337                printk(KERN_ERR "hostmixer: couldn't register mixer "
 338                       "device!\n");
 339                unregister_sound_dsp(module_data.dev_audio);
 340                return -ENODEV;
 341        }
 342
 343        return 0;
 344}
 345
 346static void __exit hostaudio_cleanup_module (void)
 347{
 348        unregister_sound_mixer(module_data.dev_mixer);
 349        unregister_sound_dsp(module_data.dev_audio);
 350}
 351
 352module_init(hostaudio_init_module);
 353module_exit(hostaudio_cleanup_module);
 354