arch/um/drivers/hostaudio_kern.c

   1 /*
   2  * Copyright (C) 2002 Steve Schmidtke
   3  * Licensed under the GPL
   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 "asm/uaccess.h"
  13 #include "init.h"
  14 #include "os.h"
  15
  16 struct hostaudio_state {
  17         int fd;
  18 };
  19
  20 struct 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  */
  32 static char *dsp = HOSTAUDIO_DEV_DSP;
  33 static 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
  43 module_param(dsp, charp, 0644);
  44 MODULE_PARM_DESC(dsp, DSP_HELP);
  45 module_param(mixer, charp, 0644);
  46 MODULE_PARM_DESC(mixer, MIXER_HELP);
  47
  48 #ifndef MODULE
  49 static 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
  57 static 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
  66 static DEFINE_MUTEX(hostaudio_mutex);
  67
  68 /* /dev/dsp file operations */
  69
  70 static 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
  92 out:
  93         kfree(kbuf);
  94         return err;
  95 }
  96
  97 static 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 = kmalloc(count, GFP_KERNEL);
 109         if (kbuf == NULL)
 110                 return -ENOMEM;
 111
 112         err = -EFAULT;
 113         if (copy_from_user(kbuf, buffer, count))
 114                 goto out;
 115
 116         err = os_write_file(state->fd, kbuf, count);
 117         if (err < 0)
 118                 goto out;
 119         *ppos += err;
 120
 121  out:
 122         kfree(kbuf);
 123         return err;
 124 }
 125
 126 static unsigned int hostaudio_poll(struct file *file,
 127                                    struct poll_table_struct *wait)
 128 {
 129         unsigned int mask = 0;
 130
 131 #ifdef DEBUG
 132         printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
 133 #endif
 134
 135         return mask;
 136 }
 137
 138 static long hostaudio_ioctl(struct file *file,
 139                            unsigned int cmd, unsigned long arg)
 140 {
 141         struct hostaudio_state *state = file->private_data;
 142         unsigned long data = 0;
 143         int err;
 144
 145 #ifdef DEBUG
 146         printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
 147 #endif
 148         switch(cmd){
 149         case SNDCTL_DSP_SPEED:
 150         case SNDCTL_DSP_STEREO:
 151         case SNDCTL_DSP_GETBLKSIZE:
 152         case SNDCTL_DSP_CHANNELS:
 153         case SNDCTL_DSP_SUBDIVIDE:
 154         case SNDCTL_DSP_SETFRAGMENT:
 155                 if (get_user(data, (int __user *) arg))
 156                         return -EFAULT;
 157                 break;
 158         default:
 159                 break;
 160         }
 161
 162         err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
 163
 164         switch(cmd){
 165         case SNDCTL_DSP_SPEED:
 166         case SNDCTL_DSP_STEREO:
 167         case SNDCTL_DSP_GETBLKSIZE:
 168         case SNDCTL_DSP_CHANNELS:
 169         case SNDCTL_DSP_SUBDIVIDE:
 170         case SNDCTL_DSP_SETFRAGMENT:
 171                 if (put_user(data, (int __user *) arg))
 172                         return -EFAULT;
 173                 break;
 174         default:
 175                 break;
 176         }
 177
 178         return err;
 179 }
 180
 181 static int hostaudio_open(struct inode *inode, struct file *file)
 182 {
 183         struct hostaudio_state *state;
 184         int r = 0, w = 0;
 185         int ret;
 186
 187 #ifdef DEBUG
 188         kparam_block_sysfs_write(dsp);
 189         printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
 190         kparam_unblock_sysfs_write(dsp);
 191 #endif
 192
 193         state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
 194         if (state == NULL)
 195                 return -ENOMEM;
 196
 197         if (file->f_mode & FMODE_READ)
 198                 r = 1;
 199         if (file->f_mode & FMODE_WRITE)
 200                 w = 1;
 201
 202         kparam_block_sysfs_write(dsp);
 203         mutex_lock(&hostaudio_mutex);
 204         ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
 205         mutex_unlock(&hostaudio_mutex);
 206         kparam_unblock_sysfs_write(dsp);
 207
 208         if (ret < 0) {
 209                 kfree(state);
 210                 return ret;
 211         }
 212         state->fd = ret;
 213         file->private_data = state;
 214         return 0;
 215 }
 216
 217 static int hostaudio_release(struct inode *inode, struct file *file)
 218 {
 219         struct hostaudio_state *state = file->private_data;
 220
 221 #ifdef DEBUG
 222         printk(KERN_DEBUG "hostaudio: release called\n");
 223 #endif
 224         os_close_file(state->fd);
 225         kfree(state);
 226
 227         return 0;
 228 }
 229
 230 /* /dev/mixer file operations */
 231
 232 static long hostmixer_ioctl_mixdev(struct file *file,
 233                                   unsigned int cmd, unsigned long arg)
 234 {
 235         struct hostmixer_state *state = file->private_data;
 236
 237 #ifdef DEBUG
 238         printk(KERN_DEBUG "hostmixer: ioctl called\n");
 239 #endif
 240
 241         return os_ioctl_generic(state->fd, cmd, arg);
 242 }
 243
 244 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
 245 {
 246         struct hostmixer_state *state;
 247         int r = 0, w = 0;
 248         int ret;
 249
 250 #ifdef DEBUG
 251         printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
 252 #endif
 253
 254         state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
 255         if (state == NULL)
 256                 return -ENOMEM;
 257
 258         if (file->f_mode & FMODE_READ)
 259                 r = 1;
 260         if (file->f_mode & FMODE_WRITE)
 261                 w = 1;
 262
 263         kparam_block_sysfs_write(mixer);
 264         mutex_lock(&hostaudio_mutex);
 265         ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
 266         mutex_unlock(&hostaudio_mutex);
 267         kparam_unblock_sysfs_write(mixer);
 268
 269         if (ret < 0) {
 270                 kparam_block_sysfs_write(dsp);
 271                 printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
 272                        "err = %d\n", dsp, -ret);
 273                 kparam_unblock_sysfs_write(dsp);
 274                 kfree(state);
 275                 return ret;
 276         }
 277
 278         file->private_data = state;
 279         return 0;
 280 }
 281
 282 static int hostmixer_release(struct inode *inode, struct file *file)
 283 {
 284         struct hostmixer_state *state = file->private_data;
 285
 286 #ifdef DEBUG
 287         printk(KERN_DEBUG "hostmixer: release called\n");
 288 #endif
 289
 290         os_close_file(state->fd);
 291         kfree(state);
 292
 293         return 0;
 294 }
 295
 296 /* kernel module operations */
 297
 298 static const struct file_operations hostaudio_fops = {
 299         .owner          = THIS_MODULE,
 300         .llseek         = no_llseek,
 301         .read           = hostaudio_read,
 302         .write          = hostaudio_write,
 303         .poll           = hostaudio_poll,
 304         .unlocked_ioctl = hostaudio_ioctl,
 305         .mmap           = NULL,
 306         .open           = hostaudio_open,
 307         .release        = hostaudio_release,
 308 };
 309
 310 static const struct file_operations hostmixer_fops = {
 311         .owner          = THIS_MODULE,
 312         .llseek         = no_llseek,
 313         .unlocked_ioctl = hostmixer_ioctl_mixdev,
 314         .open           = hostmixer_open_mixdev,
 315         .release        = hostmixer_release,
 316 };
 317
 318 struct {
 319         int dev_audio;
 320         int dev_mixer;
 321 } module_data;
 322
 323 MODULE_AUTHOR("Steve Schmidtke");
 324 MODULE_DESCRIPTION("UML Audio Relay");
 325 MODULE_LICENSE("GPL");
 326
 327 static int __init hostaudio_init_module(void)
 328 {
 329         __kernel_param_lock();
 330         printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
 331                dsp, mixer);
 332         __kernel_param_unlock();
 333
 334         module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
 335         if (module_data.dev_audio < 0) {
 336                 printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
 337                 return -ENODEV;
 338         }
 339
 340         module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
 341         if (module_data.dev_mixer < 0) {
 342                 printk(KERN_ERR "hostmixer: couldn't register mixer "
 343                        "device!\n");
 344                 unregister_sound_dsp(module_data.dev_audio);
 345                 return -ENODEV;
 346         }
 347
 348         return 0;
 349 }
 350
 351 static void __exit hostaudio_cleanup_module (void)
 352 {
 353         unregister_sound_mixer(module_data.dev_mixer);
 354         unregister_sound_dsp(module_data.dev_audio);
 355 }
 356
 357 module_init(hostaudio_init_module);
 358 module_exit(hostaudio_cleanup_module);