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        __poll_t mask = 0;
 126
 127#ifdef DEBUG
 128        printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
 129#endif
 130
 131        return mask;
 132}
 133
 134static long hostaudio_ioctl(struct file *file,
 135                           unsigned int cmd, unsigned long arg)
 136{
 137        struct hostaudio_state *state = file->private_data;
 138        unsigned long data = 0;
 139        int err;
 140
 141#ifdef DEBUG
 142        printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
 143#endif
 144        switch(cmd){
 145        case SNDCTL_DSP_SPEED:
 146        case SNDCTL_DSP_STEREO:
 147        case SNDCTL_DSP_GETBLKSIZE:
 148        case SNDCTL_DSP_CHANNELS:
 149        case SNDCTL_DSP_SUBDIVIDE:
 150        case SNDCTL_DSP_SETFRAGMENT:
 151                if (get_user(data, (int __user *) arg))
 152                        return -EFAULT;
 153                break;
 154        default:
 155                break;
 156        }
 157
 158        err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
 159
 160        switch(cmd){
 161        case SNDCTL_DSP_SPEED:
 162        case SNDCTL_DSP_STEREO:
 163        case SNDCTL_DSP_GETBLKSIZE:
 164        case SNDCTL_DSP_CHANNELS:
 165        case SNDCTL_DSP_SUBDIVIDE:
 166        case SNDCTL_DSP_SETFRAGMENT:
 167                if (put_user(data, (int __user *) arg))
 168                        return -EFAULT;
 169                break;
 170        default:
 171                break;
 172        }
 173
 174        return err;
 175}
 176
 177static int hostaudio_open(struct inode *inode, struct file *file)
 178{
 179        struct hostaudio_state *state;
 180        int r = 0, w = 0;
 181        int ret;
 182
 183#ifdef DEBUG
 184        kernel_param_lock(THIS_MODULE);
 185        printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
 186        kernel_param_unlock(THIS_MODULE);
 187#endif
 188
 189        state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
 190        if (state == NULL)
 191                return -ENOMEM;
 192
 193        if (file->f_mode & FMODE_READ)
 194                r = 1;
 195        if (file->f_mode & FMODE_WRITE)
 196                w = 1;
 197
 198        kernel_param_lock(THIS_MODULE);
 199        mutex_lock(&hostaudio_mutex);
 200        ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
 201        mutex_unlock(&hostaudio_mutex);
 202        kernel_param_unlock(THIS_MODULE);
 203
 204        if (ret < 0) {
 205                kfree(state);
 206                return ret;
 207        }
 208        state->fd = ret;
 209        file->private_data = state;
 210        return 0;
 211}
 212
 213static int hostaudio_release(struct inode *inode, struct file *file)
 214{
 215        struct hostaudio_state *state = file->private_data;
 216
 217#ifdef DEBUG
 218        printk(KERN_DEBUG "hostaudio: release called\n");
 219#endif
 220        os_close_file(state->fd);
 221        kfree(state);
 222
 223        return 0;
 224}
 225
 226/* /dev/mixer file operations */
 227
 228static long hostmixer_ioctl_mixdev(struct file *file,
 229                                  unsigned int cmd, unsigned long arg)
 230{
 231        struct hostmixer_state *state = file->private_data;
 232
 233#ifdef DEBUG
 234        printk(KERN_DEBUG "hostmixer: ioctl called\n");
 235#endif
 236
 237        return os_ioctl_generic(state->fd, cmd, arg);
 238}
 239
 240static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
 241{
 242        struct hostmixer_state *state;
 243        int r = 0, w = 0;
 244        int ret;
 245
 246#ifdef DEBUG
 247        printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
 248#endif
 249
 250        state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
 251        if (state == NULL)
 252                return -ENOMEM;
 253
 254        if (file->f_mode & FMODE_READ)
 255                r = 1;
 256        if (file->f_mode & FMODE_WRITE)
 257                w = 1;
 258
 259        kernel_param_lock(THIS_MODULE);
 260        mutex_lock(&hostaudio_mutex);
 261        ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
 262        mutex_unlock(&hostaudio_mutex);
 263        kernel_param_unlock(THIS_MODULE);
 264
 265        if (ret < 0) {
 266                kernel_param_lock(THIS_MODULE);
 267                printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
 268                       "err = %d\n", dsp, -ret);
 269                kernel_param_unlock(THIS_MODULE);
 270                kfree(state);
 271                return ret;
 272        }
 273
 274        file->private_data = state;
 275        return 0;
 276}
 277
 278static int hostmixer_release(struct inode *inode, struct file *file)
 279{
 280        struct hostmixer_state *state = file->private_data;
 281
 282#ifdef DEBUG
 283        printk(KERN_DEBUG "hostmixer: release called\n");
 284#endif
 285
 286        os_close_file(state->fd);
 287        kfree(state);
 288
 289        return 0;
 290}
 291
 292/* kernel module operations */
 293
 294static const struct file_operations hostaudio_fops = {
 295        .owner          = THIS_MODULE,
 296        .llseek         = no_llseek,
 297        .read           = hostaudio_read,
 298        .write          = hostaudio_write,
 299        .poll           = hostaudio_poll,
 300        .unlocked_ioctl = hostaudio_ioctl,
 301        .compat_ioctl   = compat_ptr_ioctl,
 302        .mmap           = NULL,
 303        .open           = hostaudio_open,
 304        .release        = hostaudio_release,
 305};
 306
 307static const struct file_operations hostmixer_fops = {
 308        .owner          = THIS_MODULE,
 309        .llseek         = no_llseek,
 310        .unlocked_ioctl = hostmixer_ioctl_mixdev,
 311        .open           = hostmixer_open_mixdev,
 312        .release        = hostmixer_release,
 313};
 314
 315struct {
 316        int dev_audio;
 317        int dev_mixer;
 318} module_data;
 319
 320MODULE_AUTHOR("Steve Schmidtke");
 321MODULE_DESCRIPTION("UML Audio Relay");
 322MODULE_LICENSE("GPL");
 323
 324static int __init hostaudio_init_module(void)
 325{
 326        kernel_param_lock(THIS_MODULE);
 327        printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
 328               dsp, mixer);
 329        kernel_param_unlock(THIS_MODULE);
 330
 331        module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
 332        if (module_data.dev_audio < 0) {
 333                printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
 334                return -ENODEV;
 335        }
 336
 337        module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
 338        if (module_data.dev_mixer < 0) {
 339                printk(KERN_ERR "hostmixer: couldn't register mixer "
 340                       "device!\n");
 341                unregister_sound_dsp(module_data.dev_audio);
 342                return -ENODEV;
 343        }
 344
 345        return 0;
 346}
 347
 348static void __exit hostaudio_cleanup_module (void)
 349{
 350        unregister_sound_mixer(module_data.dev_mixer);
 351        unregister_sound_dsp(module_data.dev_audio);
 352}
 353
 354module_init(hostaudio_init_module);
 355module_exit(hostaudio_cleanup_module);
 356