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 tasklet
  27  * This avoids spinlock messes and long-running irq contexts
  28  */
  29 static void pcsp_call_pcm_elapsed(unsigned long priv)
  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_TASKLET(pcsp_pcm_tasklet, pcsp_call_pcm_elapsed, 0);
  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         }
 123         spin_unlock_irqrestore(&chip->substream_lock, flags);
 124
 125         if (periods_elapsed)
 126                 tasklet_schedule(&pcsp_pcm_tasklet);
 127 }
 128
 129 enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
 130 {
 131         struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
 132         int pointer_update;
 133         u64 ns;
 134
 135         if (!atomic_read(&chip->timer_active) || !chip->playback_substream)
 136                 return HRTIMER_NORESTART;
 137
 138         pointer_update = !chip->thalf;
 139         ns = pcsp_timer_update(chip);
 140         if (!ns) {
 141                 printk(KERN_WARNING "PCSP: unexpected stop\n");
 142                 return HRTIMER_NORESTART;
 143         }
 144
 145         if (pointer_update)
 146                 pcsp_pointer_update(chip);
 147
 148         hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
 149
 150         return HRTIMER_RESTART;
 151 }
 152
 153 static int pcsp_start_playing(struct snd_pcsp *chip)
 154 {
 155 #if PCSP_DEBUG
 156         printk(KERN_INFO "PCSP: start_playing called\n");
 157 #endif
 158         if (atomic_read(&chip->timer_active)) {
 159                 printk(KERN_ERR "PCSP: Timer already active\n");
 160                 return -EIO;
 161         }
 162
 163         raw_spin_lock(&i8253_lock);
 164         chip->val61 = inb(0x61) | 0x03;
 165         outb_p(0x92, 0x43);     /* binary, mode 1, LSB only, ch 2 */
 166         raw_spin_unlock(&i8253_lock);
 167         atomic_set(&chip->timer_active, 1);
 168         chip->thalf = 0;
 169
 170         hrtimer_start(&pcsp_chip.timer, 0, HRTIMER_MODE_REL);
 171         return 0;
 172 }
 173
 174 static void pcsp_stop_playing(struct snd_pcsp *chip)
 175 {
 176 #if PCSP_DEBUG
 177         printk(KERN_INFO "PCSP: stop_playing called\n");
 178 #endif
 179         if (!atomic_read(&chip->timer_active))
 180                 return;
 181
 182         atomic_set(&chip->timer_active, 0);
 183         raw_spin_lock(&i8253_lock);
 184         /* restore the timer */
 185         outb_p(0xb6, 0x43);     /* binary, mode 3, LSB/MSB, ch 2 */
 186         outb(chip->val61 & 0xFC, 0x61);
 187         raw_spin_unlock(&i8253_lock);
 188 }
 189
 190 /*
 191  * Force to stop and sync the stream
 192  */
 193 void pcsp_sync_stop(struct snd_pcsp *chip)
 194 {
 195         local_irq_disable();
 196         pcsp_stop_playing(chip);
 197         local_irq_enable();
 198         hrtimer_cancel(&chip->timer);
 199         tasklet_kill(&pcsp_pcm_tasklet);
 200 }
 201
 202 static int snd_pcsp_playback_close(struct snd_pcm_substream *substream)
 203 {
 204         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 205 #if PCSP_DEBUG
 206         printk(KERN_INFO "PCSP: close called\n");
 207 #endif
 208         pcsp_sync_stop(chip);
 209         chip->playback_substream = NULL;
 210         return 0;
 211 }
 212
 213 static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream,
 214                                        struct snd_pcm_hw_params *hw_params)
 215 {
 216         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 217         pcsp_sync_stop(chip);
 218         return 0;
 219 }
 220
 221 static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream)
 222 {
 223         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 224 #if PCSP_DEBUG
 225         printk(KERN_INFO "PCSP: hw_free called\n");
 226 #endif
 227         pcsp_sync_stop(chip);
 228         return 0;
 229 }
 230
 231 static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream)
 232 {
 233         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 234         pcsp_sync_stop(chip);
 235         chip->playback_ptr = 0;
 236         chip->period_ptr = 0;
 237         chip->fmt_size =
 238                 snd_pcm_format_physical_width(substream->runtime->format) >> 3;
 239         chip->is_signed = snd_pcm_format_signed(substream->runtime->format);
 240 #if PCSP_DEBUG
 241         printk(KERN_INFO "PCSP: prepare called, "
 242                         "size=%zi psize=%zi f=%zi f1=%i fsize=%i\n",
 243                         snd_pcm_lib_buffer_bytes(substream),
 244                         snd_pcm_lib_period_bytes(substream),
 245                         snd_pcm_lib_buffer_bytes(substream) /
 246                         snd_pcm_lib_period_bytes(substream),
 247                         substream->runtime->periods,
 248                         chip->fmt_size);
 249 #endif
 250         return 0;
 251 }
 252
 253 static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd)
 254 {
 255         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 256 #if PCSP_DEBUG
 257         printk(KERN_INFO "PCSP: trigger called\n");
 258 #endif
 259         switch (cmd) {
 260         case SNDRV_PCM_TRIGGER_START:
 261         case SNDRV_PCM_TRIGGER_RESUME:
 262                 return pcsp_start_playing(chip);
 263         case SNDRV_PCM_TRIGGER_STOP:
 264         case SNDRV_PCM_TRIGGER_SUSPEND:
 265                 pcsp_stop_playing(chip);
 266                 break;
 267         default:
 268                 return -EINVAL;
 269         }
 270         return 0;
 271 }
 272
 273 static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream
 274                                                    *substream)
 275 {
 276         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 277         unsigned int pos;
 278         spin_lock(&chip->substream_lock);
 279         pos = chip->playback_ptr;
 280         spin_unlock(&chip->substream_lock);
 281         return bytes_to_frames(substream->runtime, pos);
 282 }
 283
 284 static const struct snd_pcm_hardware snd_pcsp_playback = {
 285         .info = (SNDRV_PCM_INFO_INTERLEAVED |
 286                  SNDRV_PCM_INFO_HALF_DUPLEX |
 287                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
 288         .formats = (SNDRV_PCM_FMTBIT_U8
 289 #if DMIX_WANTS_S16
 290                     | SNDRV_PCM_FMTBIT_S16_LE
 291 #endif
 292             ),
 293         .rates = SNDRV_PCM_RATE_KNOT,
 294         .rate_min = PCSP_DEFAULT_SRATE,
 295         .rate_max = PCSP_DEFAULT_SRATE,
 296         .channels_min = 1,
 297         .channels_max = 1,
 298         .buffer_bytes_max = PCSP_BUFFER_SIZE,
 299         .period_bytes_min = 64,
 300         .period_bytes_max = PCSP_MAX_PERIOD_SIZE,
 301         .periods_min = 2,
 302         .periods_max = PCSP_MAX_PERIODS,
 303         .fifo_size = 0,
 304 };
 305
 306 static int snd_pcsp_playback_open(struct snd_pcm_substream *substream)
 307 {
 308         struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
 309         struct snd_pcm_runtime *runtime = substream->runtime;
 310 #if PCSP_DEBUG
 311         printk(KERN_INFO "PCSP: open called\n");
 312 #endif
 313         if (atomic_read(&chip->timer_active)) {
 314                 printk(KERN_ERR "PCSP: still active!!\n");
 315                 return -EBUSY;
 316         }
 317         runtime->hw = snd_pcsp_playback;
 318         chip->playback_substream = substream;
 319         return 0;
 320 }
 321
 322 static const struct snd_pcm_ops snd_pcsp_playback_ops = {
 323         .open = snd_pcsp_playback_open,
 324         .close = snd_pcsp_playback_close,
 325         .hw_params = snd_pcsp_playback_hw_params,
 326         .hw_free = snd_pcsp_playback_hw_free,
 327         .prepare = snd_pcsp_playback_prepare,
 328         .trigger = snd_pcsp_trigger,
 329         .pointer = snd_pcsp_playback_pointer,
 330 };
 331
 332 int snd_pcsp_new_pcm(struct snd_pcsp *chip)
 333 {
 334         int err;
 335
 336         err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm);
 337         if (err < 0)
 338                 return err;
 339
 340         snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK,
 341                         &snd_pcsp_playback_ops);
 342
 343         chip->pcm->private_data = chip;
 344         chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
 345         strcpy(chip->pcm->name, "pcsp");
 346
 347         snd_pcm_set_managed_buffer_all(chip->pcm,
 348                                        SNDRV_DMA_TYPE_CONTINUOUS,
 349                                        NULL,
 350                                        PCSP_BUFFER_SIZE,
 351                                        PCSP_BUFFER_SIZE);
 352
 353         return 0;
 354 }