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_now(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 } 353