sound/drivers/pcsp/pcsp_lib.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PC-Speaker driver for Linux
   4  *
   5  * Copyright (C) 1993-1997  Michael Beck
   6  * Copyright (C) 1997-2001  David Woodhouse
   7  * Copyright (C) 2001-2008  Stas Sergeev
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/gfp.h>
  12 #include <linux/moduleparam.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/io.h>
  15 #include <sound/pcm.h>
  16 #include "pcsp.h"
  17
  18 static bool nforce_wa;
  19 module_param(nforce_wa, bool, 0444);
  20 MODULE_PARM_DESC(nforce_wa, "Apply NForce chipset workaround "
  21                 "(expect bad sound)");
  22
  23 #define DMIX_WANTS_S16  1
  24
  25 /*
  26  * Call snd_pcm_period_elapsed in a work
  27  * This avoids spinlock messes and long-running irq contexts
  28  */
  29 static void pcsp_call_pcm_elapsed(struct work_struct *work)
  30 {
  31         if (atomic_read(&pcsp_chip.timer_active)) {
  32                 struct snd_pcm_substream *substream;
  33                 substream = pcsp_chip.playback_substream;
  34                 if (substream)
  35                         snd_pcm_period_elapsed(substream);
  36         }
  37 }
  38
  39 static DECLARE_WORK(pcsp_pcm_work, pcsp_call_pcm_elapsed);
  40
  41 /* write the port and returns the next expire time in ns;
  42  * called at the trigger-start and in hrtimer callback
  43  */
  44 static u64 pcsp_timer_update(struct snd_pcsp *chip)
  45 {
  46         unsigned char timer_cnt, val;
  47         u64 ns;
  48         struct snd_pcm_substream *substream;
  49         struct snd_pcm_runtime *runtime;
  50         unsigned long flags;
  51
  52         if (chip->thalf) {
  53                 outb(chip->val61, 0x61);
  54                 chip->thalf = 0;
  55                 return chip->ns_rem;
  56         }
  57
  58         substream = chip->playback_substream;
  59         if (!substream)
  60                 return 0;
  61
  62         runtime = substream->runtime;
  63         /* assume it is mono! */
  64         val = runtime->dma_area[chip->playback_ptr + chip->fmt_size - 1];
  65         if (chip->is_signed)
  66                 val ^= 0x80;
  67         timer_cnt = val * CUR_DIV() / 256;
  68
  69         if (timer_cnt && chip->enable) {
  70                 raw_spin_lock_irqsave(&i8253_lock, flags);
  71                 if (!nforce_wa) {
  72                         outb_p(chip->val61, 0x61);
  73                         outb_p(timer_cnt, 0x42);
  74                         outb(chip->val61 ^ 1, 0x61);
  75                 } else {
  76                         outb(chip->val61 ^ 2, 0x61);
  77                         chip->thalf = 1;
  78                 }
  79                 raw_spin_unlock_irqrestore(&i8253_lock, flags);
  80         }
  81
  82         chip->ns_rem = PCSP_PERIOD_NS();
  83         ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
  84         chip->ns_rem -= ns;
  85         return ns;
  86 }
  87
  88 static void pcsp_pointer_update(struct snd_pcsp *chip)
  89 {
  90         struct snd_pcm_substream *substream;
  91         size_t period_bytes, buffer_bytes;
  92         int periods_elapsed;
  93         unsigned long flags;
  94
  95         /* update the playback position */
  96         substream = chip->playback_substream;
  97         if (!substream)
  98                 return;
  99
 100         period_bytes = snd_pcm_lib_period_bytes(substream);
 101         buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
 102
 103         spin_lock_irqsave(&chip->substream_lock, flags);
 104         chip->playback_ptr += PCSP_INDEX_INC() * chip->fmt_size;
 105         periods_elapsed = chip->playback_ptr - chip->period_ptr;
 106         if (periods_elapsed < 0) {
 107 #if PCSP_DEBUG
 108                 printk(KERN_INFO "PCSP: buffer_bytes mod period_bytes != 0 ? "
 109                         "(%zi %zi %zi)\n",
 110                         chip->playback_ptr, period_bytes, buffer_bytes);
 111 #endif
 112                 periods_elapsed += buffer_bytes;
 113         }
 114         periods_elapsed /= period_bytes;
 115         /* wrap the pointer _before_ calling snd_pcm_period_elapsed(),
 116          * or ALSA will BUG on us. */
 117         chip->playback_ptr %= buffer_bytes;
 118
 119         if (periods_elapsed) {
 120                 chip->period_ptr += periods_elapsed * period_bytes;
 121                 chip->period_ptr %= buffer_bytes;
 122                 queue_work(system_highpri_wq, &pcsp_pcm_work);
 123         }
 124         spin_unlock_irqrestore(&chip->substream_lock, flags);
 125 }
 126
 127 enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
 128 {
 129         struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
 130         int pointer_update;
 131         u64 ns;
 132
 133         if (!atomic_read(&chip->timer_active) || !chip->playback_substream)
 134                 return HRTIMER_NORESTART;
 135
 136         pointer_update = !chip->thalf;
 137         ns = pcsp_timer_update(chip);
 138         if (!ns) {
 139                 printk(KERN_WARNING "PCSP: unexpected stop\n");
 140                 return HRTIMER_NORESTART;
 141         }
 142
 143         if (pointer_update)
 144                 pcsp_pointer_update(chip);
 145
 146         hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
 147
 148         return HRTIMER_RESTART;
 149 }
 150
 151 static int pcsp_start_playing(struct snd_pcsp *chip)
 152 {
 153 #if PCSP_DEBUG
 154         printk(KERN_INFO "PCSP: start_playing called\n");
 155 #endif
 156         if (atomic_read(&chip->timer_active)) {
 157                 printk(KERN_ERR "PCSP: Timer already active\n");
 158                 return -EIO;
 159         }
 160
 161         raw_spin_lock(&i8253_lock);
 162         chip->val61 = inb(0x61) | 0x03;
 163         outb_p(0x92, 0x43);     /* binary, mode 1, LSB only, ch 2 */
 164         raw_spin_unlock(&i8253_lock);
 165         atomic_set(&chip->timer_active, 1);
 166         chip->thalf = 0;
 167
 168         hrtimer_start(&pcsp_chip.timer, 0, HRTIMER_MODE_REL);
 169         return 0;
 170 }
 171
 172 static void pcsp_stop_playing(struct snd_pcsp *chip)
 173 {
 174 #if PCSP_DEBUG
 175         printk(KERN_INFO "PCSP: stop_playing called\n");
 176 #endif
 177         if (!atomic_read(&chip->timer_active))
 178                 return;
 179
 180         atomic_set(&chip->timer_active, 0);
 181         raw_spin_lock(&i8253_lock);
 182         /* restore the timer */
 183         outb_p(0xb6, 0x43);     /* binary, mode 3, LSB/MSB, ch 2 */
 184         outb(chip->val61 & 0xFC, 0x61);
 185         raw_spin_unlock(&i8253_lock);
 186 }
 187
 188 /*
 189  * Force to stop and sync the stream
 190  */
 191 void pcsp_sync_stop(struct snd_pcsp *chip)
 192 {
 193         local_irq_disable();
 194         pcsp_stop_playing(chip);
 195         local_irq_enable();
 196         hrtimer_cancel(&chip->timer);
 197         cancel_work_sync(&pcsp_pcm_work);
 198 }
 199
 200 static int snd_pcsp_playback_close(struct snd_pcm_substream *substream)
 201 {
 202         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 203 #if PCSP_DEBUG
 204         printk(KERN_INFO "PCSP: close called\n");
 205 #endif
 206         pcsp_sync_stop(chip);
 207         chip->playback_substream = NULL;
 208         return 0;
 209 }
 210
 211 static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream,
 212                                        struct snd_pcm_hw_params *hw_params)
 213 {
 214         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 215         pcsp_sync_stop(chip);
 216         return 0;
 217 }
 218
 219 static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream)
 220 {
 221         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 222 #if PCSP_DEBUG
 223         printk(KERN_INFO "PCSP: hw_free called\n");
 224 #endif
 225         pcsp_sync_stop(chip);
 226         return 0;
 227 }
 228
 229 static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream)
 230 {
 231         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 232         pcsp_sync_stop(chip);
 233         chip->playback_ptr = 0;
 234         chip->period_ptr = 0;
 235         chip->fmt_size =
 236                 snd_pcm_format_physical_width(substream->runtime->format) >> 3;
 237         chip->is_signed = snd_pcm_format_signed(substream->runtime->format);
 238 #if PCSP_DEBUG
 239         printk(KERN_INFO "PCSP: prepare called, "
 240                         "size=%zi psize=%zi f=%zi f1=%i fsize=%i\n",
 241                         snd_pcm_lib_buffer_bytes(substream),
 242                         snd_pcm_lib_period_bytes(substream),
 243                         snd_pcm_lib_buffer_bytes(substream) /
 244                         snd_pcm_lib_period_bytes(substream),
 245                         substream->runtime->periods,
 246                         chip->fmt_size);
 247 #endif
 248         return 0;
 249 }
 250
 251 static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd)
 252 {
 253         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 254 #if PCSP_DEBUG
 255         printk(KERN_INFO "PCSP: trigger called\n");
 256 #endif
 257         switch (cmd) {
 258         case SNDRV_PCM_TRIGGER_START:
 259         case SNDRV_PCM_TRIGGER_RESUME:
 260                 return pcsp_start_playing(chip);
 261         case SNDRV_PCM_TRIGGER_STOP:
 262         case SNDRV_PCM_TRIGGER_SUSPEND:
 263                 pcsp_stop_playing(chip);
 264                 break;
 265         default:
 266                 return -EINVAL;
 267         }
 268         return 0;
 269 }
 270
 271 static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream
 272                                                    *substream)
 273 {
 274         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 275         unsigned int pos;
 276         spin_lock(&chip->substream_lock);
 277         pos = chip->playback_ptr;
 278         spin_unlock(&chip->substream_lock);
 279         return bytes_to_frames(substream->runtime, pos);
 280 }
 281
 282 static const struct snd_pcm_hardware snd_pcsp_playback = {
 283         .info = (SNDRV_PCM_INFO_INTERLEAVED |
 284                  SNDRV_PCM_INFO_HALF_DUPLEX |
 285                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
 286         .formats = (SNDRV_PCM_FMTBIT_U8
 287 #if DMIX_WANTS_S16
 288                     | SNDRV_PCM_FMTBIT_S16_LE
 289 #endif
 290             ),
 291         .rates = SNDRV_PCM_RATE_KNOT,
 292         .rate_min = PCSP_DEFAULT_SRATE,
 293         .rate_max = PCSP_DEFAULT_SRATE,
 294         .channels_min = 1,
 295         .channels_max = 1,
 296         .buffer_bytes_max = PCSP_BUFFER_SIZE,
 297         .period_bytes_min = 64,
 298         .period_bytes_max = PCSP_MAX_PERIOD_SIZE,
 299         .periods_min = 2,
 300         .periods_max = PCSP_MAX_PERIODS,
 301         .fifo_size = 0,
 302 };
 303
 304 static int snd_pcsp_playback_open(struct snd_pcm_substream *substream)
 305 {
 306         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 307         struct snd_pcm_runtime *runtime = substream->runtime;
 308 #if PCSP_DEBUG
 309         printk(KERN_INFO "PCSP: open called\n");
 310 #endif
 311         if (atomic_read(&chip->timer_active)) {
 312                 printk(KERN_ERR "PCSP: still active!!\n");
 313                 return -EBUSY;
 314         }
 315         runtime->hw = snd_pcsp_playback;
 316         chip->playback_substream = substream;
 317         return 0;
 318 }
 319
 320 static const struct snd_pcm_ops snd_pcsp_playback_ops = {
 321         .open = snd_pcsp_playback_open,
 322         .close = snd_pcsp_playback_close,
 323         .hw_params = snd_pcsp_playback_hw_params,
 324         .hw_free = snd_pcsp_playback_hw_free,
 325         .prepare = snd_pcsp_playback_prepare,
 326         .trigger = snd_pcsp_trigger,
 327         .pointer = snd_pcsp_playback_pointer,
 328 };
 329
 330 int snd_pcsp_new_pcm(struct snd_pcsp *chip)
 331 {
 332         int err;
 333
 334         err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm);
 335         if (err < 0)
 336                 return err;
 337
 338         snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK,
 339                         &snd_pcsp_playback_ops);
 340
 341         chip->pcm->private_data = chip;
 342         chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
 343         strcpy(chip->pcm->name, "pcsp");
 344
 345         snd_pcm_set_managed_buffer_all(chip->pcm,
 346                                        SNDRV_DMA_TYPE_CONTINUOUS,
 347                                        NULL,
 348                                        PCSP_BUFFER_SIZE,
 349                                        PCSP_BUFFER_SIZE);
 350
 351         return 0;
 352 }