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
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