sound/oss/sh_dac_audio.c

   1 /*
   2  * sound/oss/sh_dac_audio.c
   3  *
   4  * SH DAC based sound :(
   5  *
   6  *  Copyright (C) 2004,2005  Andriy Skulysh
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/sched.h>
  15 #include <linux/linkage.h>
  16 #include <linux/slab.h>
  17 #include <linux/fs.h>
  18 #include <linux/smp_lock.h>
  19 #include <linux/sound.h>
  20 #include <linux/smp_lock.h>
  21 #include <linux/soundcard.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/hrtimer.h>
  24 #include <asm/io.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/irq.h>
  27 #include <asm/delay.h>
  28 #include <asm/clock.h>
  29 #include <cpu/dac.h>
  30 #include <asm/machvec.h>
  31 #include <mach/hp6xx.h>
  32 #include <asm/hd64461.h>
  33
  34 #define MODNAME "sh_dac_audio"
  35
  36 #define BUFFER_SIZE 48000
  37
  38 static int rate;
  39 static int empty;
  40 static char *data_buffer, *buffer_begin, *buffer_end;
  41 static int in_use, device_major;
  42 static struct hrtimer hrtimer;
  43 static ktime_t wakeups_per_second;
  44
  45 static void dac_audio_start_timer(void)
  46 {
  47         hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
  48 }
  49
  50 static void dac_audio_stop_timer(void)
  51 {
  52         hrtimer_cancel(&hrtimer);
  53 }
  54
  55 static void dac_audio_reset(void)
  56 {
  57         dac_audio_stop_timer();
  58         buffer_begin = buffer_end = data_buffer;
  59         empty = 1;
  60 }
  61
  62 static void dac_audio_sync(void)
  63 {
  64         while (!empty)
  65                 schedule();
  66 }
  67
  68 static void dac_audio_start(void)
  69 {
  70         if (mach_is_hp6xx()) {
  71                 u16 v = __raw_readw(HD64461_GPADR);
  72                 v &= ~HD64461_GPADR_SPEAKER;
  73                 __raw_writew(v, HD64461_GPADR);
  74         }
  75
  76         sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
  77 }
  78 static void dac_audio_stop(void)
  79 {
  80         dac_audio_stop_timer();
  81
  82         if (mach_is_hp6xx()) {
  83                 u16 v = __raw_readw(HD64461_GPADR);
  84                 v |= HD64461_GPADR_SPEAKER;
  85                 __raw_writew(v, HD64461_GPADR);
  86         }
  87
  88         sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
  89         sh_dac_disable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
  90 }
  91
  92 static void dac_audio_set_rate(void)
  93 {
  94         wakeups_per_second = ktime_set(0, 1000000000 / rate);
  95 }
  96
  97 static int dac_audio_ioctl(struct file *file,
  98                            unsigned int cmd, unsigned long arg)
  99 {
 100         int val;
 101
 102         switch (cmd) {
 103         case OSS_GETVERSION:
 104                 return put_user(SOUND_VERSION, (int *)arg);
 105
 106         case SNDCTL_DSP_SYNC:
 107                 dac_audio_sync();
 108                 return 0;
 109
 110         case SNDCTL_DSP_RESET:
 111                 dac_audio_reset();
 112                 return 0;
 113
 114         case SNDCTL_DSP_GETFMTS:
 115                 return put_user(AFMT_U8, (int *)arg);
 116
 117         case SNDCTL_DSP_SETFMT:
 118                 return put_user(AFMT_U8, (int *)arg);
 119
 120         case SNDCTL_DSP_NONBLOCK:
 121                 spin_lock(&file->f_lock);
 122                 file->f_flags |= O_NONBLOCK;
 123                 spin_unlock(&file->f_lock);
 124                 return 0;
 125
 126         case SNDCTL_DSP_GETCAPS:
 127                 return 0;
 128
 129         case SOUND_PCM_WRITE_RATE:
 130                 val = *(int *)arg;
 131                 if (val > 0) {
 132                         rate = val;
 133                         dac_audio_set_rate();
 134                 }
 135                 return put_user(rate, (int *)arg);
 136
 137         case SNDCTL_DSP_STEREO:
 138                 return put_user(0, (int *)arg);
 139
 140         case SOUND_PCM_WRITE_CHANNELS:
 141                 return put_user(1, (int *)arg);
 142
 143         case SNDCTL_DSP_SETDUPLEX:
 144                 return -EINVAL;
 145
 146         case SNDCTL_DSP_PROFILE:
 147                 return -EINVAL;
 148
 149         case SNDCTL_DSP_GETBLKSIZE:
 150                 return put_user(BUFFER_SIZE, (int *)arg);
 151
 152         case SNDCTL_DSP_SETFRAGMENT:
 153                 return 0;
 154
 155         default:
 156                 printk(KERN_ERR "sh_dac_audio: unimplemented ioctl=0x%x\n",
 157                        cmd);
 158                 return -EINVAL;
 159         }
 160         return -EINVAL;
 161 }
 162
 163 static long dac_audio_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 164 {
 165         int ret;
 166
 167         lock_kernel();
 168         ret = dac_audio_ioctl(file, cmd, arg);
 169         unlock_kernel();
 170
 171         return ret;
 172 }
 173
 174 static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count,
 175                                loff_t * ppos)
 176 {
 177         int free;
 178         int nbytes;
 179
 180         if (!count) {
 181                 dac_audio_sync();
 182                 return 0;
 183         }
 184
 185         free = buffer_begin - buffer_end;
 186
 187         if (free < 0)
 188                 free += BUFFER_SIZE;
 189         if ((free == 0) && (empty))
 190                 free = BUFFER_SIZE;
 191         if (count > free)
 192                 count = free;
 193         if (buffer_begin > buffer_end) {
 194                 if (copy_from_user((void *)buffer_end, buf, count))
 195                         return -EFAULT;
 196
 197                 buffer_end += count;
 198         } else {
 199                 nbytes = data_buffer + BUFFER_SIZE - buffer_end;
 200                 if (nbytes > count) {
 201                         if (copy_from_user((void *)buffer_end, buf, count))
 202                                 return -EFAULT;
 203                         buffer_end += count;
 204                 } else {
 205                         if (copy_from_user((void *)buffer_end, buf, nbytes))
 206                                 return -EFAULT;
 207                         if (copy_from_user
 208                             ((void *)data_buffer, buf + nbytes, count - nbytes))
 209                                 return -EFAULT;
 210                         buffer_end = data_buffer + count - nbytes;
 211                 }
 212         }
 213
 214         if (empty) {
 215                 empty = 0;
 216                 dac_audio_start_timer();
 217         }
 218
 219         return count;
 220 }
 221
 222 static ssize_t dac_audio_read(struct file *file, char *buf, size_t count,
 223                               loff_t * ppos)
 224 {
 225         return -EINVAL;
 226 }
 227
 228 static int dac_audio_open(struct inode *inode, struct file *file)
 229 {
 230         if (file->f_mode & FMODE_READ)
 231                 return -ENODEV;
 232
 233         lock_kernel();
 234         if (in_use) {
 235                 unlock_kernel();
 236                 return -EBUSY;
 237         }
 238
 239         in_use = 1;
 240
 241         dac_audio_start();
 242         unlock_kernel();
 243         return 0;
 244 }
 245
 246 static int dac_audio_release(struct inode *inode, struct file *file)
 247 {
 248         dac_audio_sync();
 249         dac_audio_stop();
 250         in_use = 0;
 251
 252         return 0;
 253 }
 254
 255 const struct file_operations dac_audio_fops = {
 256       .read =           dac_audio_read,
 257       .write =          dac_audio_write,
 258       .unlocked_ioctl = dac_audio_unlocked_ioctl,
 259       .open =           dac_audio_open,
 260       .release =        dac_audio_release,
 261 };
 262
 263 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 264 {
 265         if (!empty) {
 266                 sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
 267                 buffer_begin++;
 268
 269                 if (buffer_begin == data_buffer + BUFFER_SIZE)
 270                         buffer_begin = data_buffer;
 271                 if (buffer_begin == buffer_end)
 272                         empty = 1;
 273         }
 274
 275         if (!empty)
 276                 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
 277
 278         return HRTIMER_NORESTART;
 279 }
 280
 281 static int __init dac_audio_init(void)
 282 {
 283         if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) {
 284                 printk(KERN_ERR "Cannot register dsp device");
 285                 return device_major;
 286         }
 287
 288         in_use = 0;
 289
 290         data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
 291         if (data_buffer == NULL)
 292                 return -ENOMEM;
 293
 294         dac_audio_reset();
 295         rate = 8000;
 296         dac_audio_set_rate();
 297
 298         /* Today: High Resolution Timer driven DAC playback.
 299          * The timer callback gets called once per sample. Ouch.
 300          *
 301          * Future: A much better approach would be to use the
 302          * SH7720 CMT+DMAC+DAC hardware combination like this:
 303          * - Program sample rate using CMT0 or CMT1
 304          * - Program DMAC to use CMT for timing and output to DAC
 305          * - Play sound using DMAC, let CPU sleep.
 306          * - While at it, rewrite this driver to use ALSA.
 307          */
 308
 309         hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 310         hrtimer.function = sh_dac_audio_timer;
 311
 312         return 0;
 313 }
 314
 315 static void __exit dac_audio_exit(void)
 316 {
 317         unregister_sound_dsp(device_major);
 318         kfree((void *)data_buffer);
 319 }
 320
 321 module_init(dac_audio_init);
 322 module_exit(dac_audio_exit);
 323
 324 MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua");
 325 MODULE_DESCRIPTION("SH DAC sound driver");
 326 MODULE_LICENSE("GPL");