1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011 Broadcom Corporation. All rights reserved. */
3
4 #include <linux/interrupt.h>
5 #include <linux/slab.h>
6
7 #include <sound/asoundef.h>
8
9 #include "bcm2835.h"
10
11 /* hardware definition */
12 static const struct snd_pcm_hardware snd_bcm2835_playback_hw = {
13 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
14 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
15 SNDRV_PCM_INFO_SYNC_APPLPTR),
16 .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
17 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
18 .rate_min = 8000,
19 .rate_max = 48000,
20 .channels_min = 1,
21 .channels_max = 2,
22 .buffer_bytes_max = 128 * 1024,
23 .period_bytes_min = 1 * 1024,
24 .period_bytes_max = 128 * 1024,
25 .periods_min = 1,
26 .periods_max = 128,
27 };
28
29 static const struct snd_pcm_hardware snd_bcm2835_playback_spdif_hw = {
30 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
31 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
32 SNDRV_PCM_INFO_SYNC_APPLPTR),
33 .formats = SNDRV_PCM_FMTBIT_S16_LE,
34 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_44100 |
35 SNDRV_PCM_RATE_48000,
36 .rate_min = 44100,
37 .rate_max = 48000,
38 .channels_min = 2,
39 .channels_max = 2,
40 .buffer_bytes_max = 128 * 1024,
41 .period_bytes_min = 1 * 1024,
42 .period_bytes_max = 128 * 1024,
43 .periods_min = 1,
44 .periods_max = 128,
45 };
46
snd_bcm2835_playback_free(struct snd_pcm_runtime * runtime)47 static void snd_bcm2835_playback_free(struct snd_pcm_runtime *runtime)
48 {
49 kfree(runtime->private_data);
50 }
51
bcm2835_playback_fifo(struct bcm2835_alsa_stream * alsa_stream,unsigned int bytes)52 void bcm2835_playback_fifo(struct bcm2835_alsa_stream *alsa_stream,
53 unsigned int bytes)
54 {
55 struct snd_pcm_substream *substream = alsa_stream->substream;
56 unsigned int pos;
57
58 if (!alsa_stream->period_size)
59 return;
60
61 if (bytes >= alsa_stream->buffer_size) {
62 snd_pcm_stream_lock(substream);
63 snd_pcm_stop(substream,
64 alsa_stream->draining ?
65 SNDRV_PCM_STATE_SETUP :
66 SNDRV_PCM_STATE_XRUN);
67 snd_pcm_stream_unlock(substream);
68 return;
69 }
70
71 pos = atomic_read(&alsa_stream->pos);
72 pos += bytes;
73 pos %= alsa_stream->buffer_size;
74 atomic_set(&alsa_stream->pos, pos);
75
76 alsa_stream->period_offset += bytes;
77 alsa_stream->interpolate_start = ktime_get();
78 if (alsa_stream->period_offset >= alsa_stream->period_size) {
79 alsa_stream->period_offset %= alsa_stream->period_size;
80 snd_pcm_period_elapsed(substream);
81 }
82 }
83
84 /* open callback */
snd_bcm2835_playback_open_generic(struct snd_pcm_substream * substream,int spdif)85 static int snd_bcm2835_playback_open_generic(
86 struct snd_pcm_substream *substream, int spdif)
87 {
88 struct bcm2835_chip *chip = snd_pcm_substream_chip(substream);
89 struct snd_pcm_runtime *runtime = substream->runtime;
90 struct bcm2835_alsa_stream *alsa_stream;
91 int idx;
92 int err;
93
94 mutex_lock(&chip->audio_mutex);
95 idx = substream->number;
96
97 if (spdif && chip->opened) {
98 err = -EBUSY;
99 goto out;
100 } else if (!spdif && (chip->opened & (1 << idx))) {
101 err = -EBUSY;
102 goto out;
103 }
104 if (idx >= MAX_SUBSTREAMS) {
105 dev_err(chip->dev,
106 "substream(%d) device doesn't exist max(%d) substreams allowed\n",
107 idx, MAX_SUBSTREAMS);
108 err = -ENODEV;
109 goto out;
110 }
111
112 alsa_stream = kzalloc(sizeof(*alsa_stream), GFP_KERNEL);
113 if (!alsa_stream) {
114 err = -ENOMEM;
115 goto out;
116 }
117
118 /* Initialise alsa_stream */
119 alsa_stream->chip = chip;
120 alsa_stream->substream = substream;
121 alsa_stream->idx = idx;
122
123 err = bcm2835_audio_open(alsa_stream);
124 if (err) {
125 kfree(alsa_stream);
126 goto out;
127 }
128 runtime->private_data = alsa_stream;
129 runtime->private_free = snd_bcm2835_playback_free;
130 if (spdif) {
131 runtime->hw = snd_bcm2835_playback_spdif_hw;
132 } else {
133 /* clear spdif status, as we are not in spdif mode */
134 chip->spdif_status = 0;
135 runtime->hw = snd_bcm2835_playback_hw;
136 }
137 /* minimum 16 bytes alignment (for vchiq bulk transfers) */
138 snd_pcm_hw_constraint_step(runtime,
139 0,
140 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
141 16);
142
143 /* position update is in 10ms order */
144 snd_pcm_hw_constraint_minmax(runtime,
145 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
146 10 * 1000, UINT_MAX);
147
148 chip->alsa_stream[idx] = alsa_stream;
149
150 chip->opened |= (1 << idx);
151
152 out:
153 mutex_unlock(&chip->audio_mutex);
154
155 return err;
156 }
157
snd_bcm2835_playback_open(struct snd_pcm_substream * substream)158 static int snd_bcm2835_playback_open(struct snd_pcm_substream *substream)
159 {
160 return snd_bcm2835_playback_open_generic(substream, 0);
161 }
162
snd_bcm2835_playback_spdif_open(struct snd_pcm_substream * substream)163 static int snd_bcm2835_playback_spdif_open(struct snd_pcm_substream *substream)
164 {
165 return snd_bcm2835_playback_open_generic(substream, 1);
166 }
167
snd_bcm2835_playback_close(struct snd_pcm_substream * substream)168 static int snd_bcm2835_playback_close(struct snd_pcm_substream *substream)
169 {
170 struct bcm2835_alsa_stream *alsa_stream;
171 struct snd_pcm_runtime *runtime;
172 struct bcm2835_chip *chip;
173
174 chip = snd_pcm_substream_chip(substream);
175 mutex_lock(&chip->audio_mutex);
176 runtime = substream->runtime;
177 alsa_stream = runtime->private_data;
178
179 alsa_stream->period_size = 0;
180 alsa_stream->buffer_size = 0;
181
182 bcm2835_audio_close(alsa_stream);
183 alsa_stream->chip->alsa_stream[alsa_stream->idx] = NULL;
184 /*
185 * Do not free up alsa_stream here, it will be freed up by
186 * runtime->private_free callback we registered in *_open above
187 */
188
189 chip->opened &= ~(1 << substream->number);
190
191 mutex_unlock(&chip->audio_mutex);
192
193 return 0;
194 }
195
snd_bcm2835_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)196 static int snd_bcm2835_pcm_hw_params(struct snd_pcm_substream *substream,
197 struct snd_pcm_hw_params *params)
198 {
199 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
200 }
201
snd_bcm2835_pcm_hw_free(struct snd_pcm_substream * substream)202 static int snd_bcm2835_pcm_hw_free(struct snd_pcm_substream *substream)
203 {
204 return snd_pcm_lib_free_pages(substream);
205 }
206
snd_bcm2835_pcm_prepare(struct snd_pcm_substream * substream)207 static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
208 {
209 struct bcm2835_chip *chip = snd_pcm_substream_chip(substream);
210 struct snd_pcm_runtime *runtime = substream->runtime;
211 struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
212 int channels;
213 int err;
214
215 /* notify the vchiq that it should enter spdif passthrough mode by
216 * setting channels=0 (see
217 * https://github.com/raspberrypi/linux/issues/528)
218 */
219 if (chip->spdif_status & IEC958_AES0_NONAUDIO)
220 channels = 0;
221 else
222 channels = runtime->channels;
223
224 err = bcm2835_audio_set_params(alsa_stream, channels,
225 runtime->rate,
226 snd_pcm_format_width(runtime->format));
227 if (err < 0)
228 return err;
229
230 memset(&alsa_stream->pcm_indirect, 0, sizeof(alsa_stream->pcm_indirect));
231
232 alsa_stream->pcm_indirect.hw_buffer_size =
233 alsa_stream->pcm_indirect.sw_buffer_size =
234 snd_pcm_lib_buffer_bytes(substream);
235
236 alsa_stream->buffer_size = snd_pcm_lib_buffer_bytes(substream);
237 alsa_stream->period_size = snd_pcm_lib_period_bytes(substream);
238 atomic_set(&alsa_stream->pos, 0);
239 alsa_stream->period_offset = 0;
240 alsa_stream->draining = false;
241 alsa_stream->interpolate_start = ktime_get();
242
243 return 0;
244 }
245
snd_bcm2835_pcm_transfer(struct snd_pcm_substream * substream,struct snd_pcm_indirect * rec,size_t bytes)246 static void snd_bcm2835_pcm_transfer(struct snd_pcm_substream *substream,
247 struct snd_pcm_indirect *rec, size_t bytes)
248 {
249 struct snd_pcm_runtime *runtime = substream->runtime;
250 struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
251 void *src = (void *) (substream->runtime->dma_area + rec->sw_data);
252
253 bcm2835_audio_write(alsa_stream, bytes, src);
254 }
255
snd_bcm2835_pcm_ack(struct snd_pcm_substream * substream)256 static int snd_bcm2835_pcm_ack(struct snd_pcm_substream *substream)
257 {
258 struct snd_pcm_runtime *runtime = substream->runtime;
259 struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
260 struct snd_pcm_indirect *pcm_indirect = &alsa_stream->pcm_indirect;
261
262 return snd_pcm_indirect_playback_transfer(substream, pcm_indirect,
263 snd_bcm2835_pcm_transfer);
264 }
265
266 /* trigger callback */
snd_bcm2835_pcm_trigger(struct snd_pcm_substream * substream,int cmd)267 static int snd_bcm2835_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
268 {
269 struct snd_pcm_runtime *runtime = substream->runtime;
270 struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
271
272 switch (cmd) {
273 case SNDRV_PCM_TRIGGER_START:
274 return bcm2835_audio_start(alsa_stream);
275 case SNDRV_PCM_TRIGGER_DRAIN:
276 alsa_stream->draining = true;
277 return bcm2835_audio_drain(alsa_stream);
278 case SNDRV_PCM_TRIGGER_STOP:
279 return bcm2835_audio_stop(alsa_stream);
280 default:
281 return -EINVAL;
282 }
283 }
284
285 /* pointer callback */
286 static snd_pcm_uframes_t
snd_bcm2835_pcm_pointer(struct snd_pcm_substream * substream)287 snd_bcm2835_pcm_pointer(struct snd_pcm_substream *substream)
288 {
289 struct snd_pcm_runtime *runtime = substream->runtime;
290 struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
291 ktime_t now = ktime_get();
292
293 /* Give userspace better delay reporting by interpolating between GPU
294 * notifications, assuming audio speed is close enough to the clock
295 * used for ktime
296 */
297
298 if ((ktime_to_ns(alsa_stream->interpolate_start)) &&
299 (ktime_compare(alsa_stream->interpolate_start, now) < 0)) {
300 u64 interval =
301 (ktime_to_ns(ktime_sub(now,
302 alsa_stream->interpolate_start)));
303 u64 frames_output_in_interval =
304 div_u64((interval * runtime->rate), 1000000000);
305 snd_pcm_sframes_t frames_output_in_interval_sized =
306 -frames_output_in_interval;
307 runtime->delay = frames_output_in_interval_sized;
308 }
309
310 return snd_pcm_indirect_playback_pointer(substream,
311 &alsa_stream->pcm_indirect,
312 atomic_read(&alsa_stream->pos));
313 }
314
315 /* operators */
316 static const struct snd_pcm_ops snd_bcm2835_playback_ops = {
317 .open = snd_bcm2835_playback_open,
318 .close = snd_bcm2835_playback_close,
319 .ioctl = snd_pcm_lib_ioctl,
320 .hw_params = snd_bcm2835_pcm_hw_params,
321 .hw_free = snd_bcm2835_pcm_hw_free,
322 .prepare = snd_bcm2835_pcm_prepare,
323 .trigger = snd_bcm2835_pcm_trigger,
324 .pointer = snd_bcm2835_pcm_pointer,
325 .ack = snd_bcm2835_pcm_ack,
326 };
327
328 static const struct snd_pcm_ops snd_bcm2835_playback_spdif_ops = {
329 .open = snd_bcm2835_playback_spdif_open,
330 .close = snd_bcm2835_playback_close,
331 .ioctl = snd_pcm_lib_ioctl,
332 .hw_params = snd_bcm2835_pcm_hw_params,
333 .hw_free = snd_bcm2835_pcm_hw_free,
334 .prepare = snd_bcm2835_pcm_prepare,
335 .trigger = snd_bcm2835_pcm_trigger,
336 .pointer = snd_bcm2835_pcm_pointer,
337 .ack = snd_bcm2835_pcm_ack,
338 };
339
340 /* create a pcm device */
snd_bcm2835_new_pcm(struct bcm2835_chip * chip,const char * name,int idx,enum snd_bcm2835_route route,u32 numchannels,bool spdif)341 int snd_bcm2835_new_pcm(struct bcm2835_chip *chip, const char *name,
342 int idx, enum snd_bcm2835_route route,
343 u32 numchannels, bool spdif)
344 {
345 struct snd_pcm *pcm;
346 int err;
347
348 err = snd_pcm_new(chip->card, name, idx, numchannels, 0, &pcm);
349 if (err)
350 return err;
351
352 pcm->private_data = chip;
353 pcm->nonatomic = true;
354 strcpy(pcm->name, name);
355 if (!spdif) {
356 chip->dest = route;
357 chip->volume = 0;
358 chip->mute = CTRL_VOL_UNMUTE;
359 }
360
361 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
362 spdif ? &snd_bcm2835_playback_spdif_ops :
363 &snd_bcm2835_playback_ops);
364
365 snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
366 chip->card->dev, 128 * 1024, 128 * 1024);
367
368 if (spdif)
369 chip->pcm_spdif = pcm;
370 else
371 chip->pcm = pcm;
372 return 0;
373 }
374
