Pileus Git - ~andy/linux/blob - 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 inode *inode, 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 ssize_t dac_audio_write(struct file *file, const char *buf, size_t count,
 163                                loff_t * ppos)
 164 {
 165         int free;
 166         int nbytes;
 167
 168         if (!count) {
 169                 dac_audio_sync();
 170                 return 0;
 171         }
 172
 173         free = buffer_begin - buffer_end;
 174
 175         if (free < 0)
 176                 free += BUFFER_SIZE;
 177         if ((free == 0) && (empty))
 178                 free = BUFFER_SIZE;
 179         if (count > free)
 180                 count = free;
 181         if (buffer_begin > buffer_end) {
 182                 if (copy_from_user((void *)buffer_end, buf, count))
 183                         return -EFAULT;
 184
 185                 buffer_end += count;
 186         } else {
 187                 nbytes = data_buffer + BUFFER_SIZE - buffer_end;
 188                 if (nbytes > count) {
 189                         if (copy_from_user((void *)buffer_end, buf, count))
 190                                 return -EFAULT;
 191                         buffer_end += count;
 192                 } else {
 193                         if (copy_from_user((void *)buffer_end, buf, nbytes))
 194                                 return -EFAULT;
 195                         if (copy_from_user
 196                             ((void *)data_buffer, buf + nbytes, count - nbytes))
 197                                 return -EFAULT;
 198                         buffer_end = data_buffer + count - nbytes;
 199                 }
 200         }
 201
 202         if (empty) {
 203                 empty = 0;
 204                 dac_audio_start_timer();
 205         }
 206
 207         return count;
 208 }
 209
 210 static ssize_t dac_audio_read(struct file *file, char *buf, size_t count,
 211                               loff_t * ppos)
 212 {
 213         return -EINVAL;
 214 }
 215
 216 static int dac_audio_open(struct inode *inode, struct file *file)
 217 {
 218         if (file->f_mode & FMODE_READ)
 219                 return -ENODEV;
 220
 221         lock_kernel();
 222         if (in_use) {
 223                 unlock_kernel();
 224                 return -EBUSY;
 225         }
 226
 227         in_use = 1;
 228
 229         dac_audio_start();
 230         unlock_kernel();
 231         return 0;
 232 }
 233
 234 static int dac_audio_release(struct inode *inode, struct file *file)
 235 {
 236         dac_audio_sync();
 237         dac_audio_stop();
 238         in_use = 0;
 239
 240         return 0;
 241 }
 242
 243 const struct file_operations dac_audio_fops = {
 244       .read =           dac_audio_read,
 245       .write =  dac_audio_write,
 246       .ioctl =  dac_audio_ioctl,
 247       .open =           dac_audio_open,
 248       .release =        dac_audio_release,
 249 };
 250
 251 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 252 {
 253         if (!empty) {
 254                 sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
 255                 buffer_begin++;
 256
 257                 if (buffer_begin == data_buffer + BUFFER_SIZE)
 258                         buffer_begin = data_buffer;
 259                 if (buffer_begin == buffer_end)
 260                         empty = 1;
 261         }
 262
 263         if (!empty)
 264                 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
 265
 266         return HRTIMER_NORESTART;
 267 }
 268
 269 static int __init dac_audio_init(void)
 270 {
 271         if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) {
 272                 printk(KERN_ERR "Cannot register dsp device");
 273                 return device_major;
 274         }
 275
 276         in_use = 0;
 277
 278         data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
 279         if (data_buffer == NULL)
 280                 return -ENOMEM;
 281
 282         dac_audio_reset();
 283         rate = 8000;
 284         dac_audio_set_rate();
 285
 286         /* Today: High Resolution Timer driven DAC playback.
 287          * The timer callback gets called once per sample. Ouch.
 288          *
 289          * Future: A much better approach would be to use the
 290          * SH7720 CMT+DMAC+DAC hardware combination like this:
 291          * - Program sample rate using CMT0 or CMT1
 292          * - Program DMAC to use CMT for timing and output to DAC
 293          * - Play sound using DMAC, let CPU sleep.
 294          * - While at it, rewrite this driver to use ALSA.
 295          */
 296
 297         hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 298         hrtimer.function = sh_dac_audio_timer;
 299
 300         return 0;
 301 }
 302
 303 static void __exit dac_audio_exit(void)
 304 {
 305         unregister_sound_dsp(device_major);
 306         kfree((void *)data_buffer);
 307 }
 308
 309 module_init(dac_audio_init);
 310 module_exit(dac_audio_exit);
 311
 312 MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua");
 313 MODULE_DESCRIPTION("SH DAC sound driver");
 314 MODULE_LICENSE("GPL");