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