1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * sh_dac_audio.c - SuperH DAC audio driver for ALSA
4 *
5 * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
6 *
7 * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
8 */
9
10 #include <linux/hrtimer.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <sound/core.h>
17 #include <sound/initval.h>
18 #include <sound/pcm.h>
19 #include <sound/sh_dac_audio.h>
20 #include <asm/clock.h>
21 #include <asm/hd64461.h>
22 #include <mach/hp6xx.h>
23 #include <cpu/dac.h>
24
25 MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
26 MODULE_DESCRIPTION("SuperH DAC audio driver");
27 MODULE_LICENSE("GPL");
28 MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
29
30 /* Module Parameters */
31 static int index = SNDRV_DEFAULT_IDX1;
32 static char *id = SNDRV_DEFAULT_STR1;
33 module_param(index, int, 0444);
34 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
35 module_param(id, charp, 0444);
36 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
37
38 /* main struct */
39 struct snd_sh_dac {
40 struct snd_card *card;
41 struct snd_pcm_substream *substream;
42 struct hrtimer hrtimer;
43 ktime_t wakeups_per_second;
44
45 int rate;
46 int empty;
47 char *data_buffer, *buffer_begin, *buffer_end;
48 int processed; /* bytes proccesed, to compare with period_size */
49 int buffer_size;
50 struct dac_audio_pdata *pdata;
51 };
52
53
dac_audio_start_timer(struct snd_sh_dac * chip)54 static void dac_audio_start_timer(struct snd_sh_dac *chip)
55 {
56 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
57 HRTIMER_MODE_REL);
58 }
59
dac_audio_stop_timer(struct snd_sh_dac * chip)60 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
61 {
62 hrtimer_cancel(&chip->hrtimer);
63 }
64
dac_audio_reset(struct snd_sh_dac * chip)65 static void dac_audio_reset(struct snd_sh_dac *chip)
66 {
67 dac_audio_stop_timer(chip);
68 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
69 chip->processed = 0;
70 chip->empty = 1;
71 }
72
dac_audio_set_rate(struct snd_sh_dac * chip)73 static void dac_audio_set_rate(struct snd_sh_dac *chip)
74 {
75 chip->wakeups_per_second = 1000000000 / chip->rate;
76 }
77
78
79 /* PCM INTERFACE */
80
81 static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
82 .info = (SNDRV_PCM_INFO_MMAP |
83 SNDRV_PCM_INFO_MMAP_VALID |
84 SNDRV_PCM_INFO_INTERLEAVED |
85 SNDRV_PCM_INFO_HALF_DUPLEX),
86 .formats = SNDRV_PCM_FMTBIT_U8,
87 .rates = SNDRV_PCM_RATE_8000,
88 .rate_min = 8000,
89 .rate_max = 8000,
90 .channels_min = 1,
91 .channels_max = 1,
92 .buffer_bytes_max = (48*1024),
93 .period_bytes_min = 1,
94 .period_bytes_max = (48*1024),
95 .periods_min = 1,
96 .periods_max = 1024,
97 };
98
snd_sh_dac_pcm_open(struct snd_pcm_substream * substream)99 static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
100 {
101 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
102 struct snd_pcm_runtime *runtime = substream->runtime;
103
104 runtime->hw = snd_sh_dac_pcm_hw;
105
106 chip->substream = substream;
107 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
108 chip->processed = 0;
109 chip->empty = 1;
110
111 chip->pdata->start(chip->pdata);
112
113 return 0;
114 }
115
snd_sh_dac_pcm_close(struct snd_pcm_substream * substream)116 static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
117 {
118 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
119
120 chip->substream = NULL;
121
122 dac_audio_stop_timer(chip);
123 chip->pdata->stop(chip->pdata);
124
125 return 0;
126 }
127
snd_sh_dac_pcm_prepare(struct snd_pcm_substream * substream)128 static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
129 {
130 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
131 struct snd_pcm_runtime *runtime = chip->substream->runtime;
132
133 chip->buffer_size = runtime->buffer_size;
134 memset(chip->data_buffer, 0, chip->pdata->buffer_size);
135
136 return 0;
137 }
138
snd_sh_dac_pcm_trigger(struct snd_pcm_substream * substream,int cmd)139 static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
140 {
141 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
142
143 switch (cmd) {
144 case SNDRV_PCM_TRIGGER_START:
145 dac_audio_start_timer(chip);
146 break;
147 case SNDRV_PCM_TRIGGER_STOP:
148 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
149 chip->processed = 0;
150 chip->empty = 1;
151 dac_audio_stop_timer(chip);
152 break;
153 default:
154 return -EINVAL;
155 }
156
157 return 0;
158 }
159
snd_sh_dac_pcm_copy(struct snd_pcm_substream * substream,int channel,unsigned long pos,void __user * src,unsigned long count)160 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
161 int channel, unsigned long pos,
162 void __user *src, unsigned long count)
163 {
164 /* channel is not used (interleaved data) */
165 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
166
167 if (copy_from_user_toio(chip->data_buffer + pos, src, count))
168 return -EFAULT;
169 chip->buffer_end = chip->data_buffer + pos + count;
170
171 if (chip->empty) {
172 chip->empty = 0;
173 dac_audio_start_timer(chip);
174 }
175
176 return 0;
177 }
178
snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream * substream,int channel,unsigned long pos,void * src,unsigned long count)179 static int snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream *substream,
180 int channel, unsigned long pos,
181 void *src, unsigned long count)
182 {
183 /* channel is not used (interleaved data) */
184 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
185
186 memcpy_toio(chip->data_buffer + pos, src, count);
187 chip->buffer_end = chip->data_buffer + pos + count;
188
189 if (chip->empty) {
190 chip->empty = 0;
191 dac_audio_start_timer(chip);
192 }
193
194 return 0;
195 }
196
snd_sh_dac_pcm_silence(struct snd_pcm_substream * substream,int channel,unsigned long pos,unsigned long count)197 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
198 int channel, unsigned long pos,
199 unsigned long count)
200 {
201 /* channel is not used (interleaved data) */
202 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
203
204 memset_io(chip->data_buffer + pos, 0, count);
205 chip->buffer_end = chip->data_buffer + pos + count;
206
207 if (chip->empty) {
208 chip->empty = 0;
209 dac_audio_start_timer(chip);
210 }
211
212 return 0;
213 }
214
215 static
snd_sh_dac_pcm_pointer(struct snd_pcm_substream * substream)216 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
217 {
218 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
219 int pointer = chip->buffer_begin - chip->data_buffer;
220
221 return pointer;
222 }
223
224 /* pcm ops */
225 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
226 .open = snd_sh_dac_pcm_open,
227 .close = snd_sh_dac_pcm_close,
228 .prepare = snd_sh_dac_pcm_prepare,
229 .trigger = snd_sh_dac_pcm_trigger,
230 .pointer = snd_sh_dac_pcm_pointer,
231 .copy_user = snd_sh_dac_pcm_copy,
232 .copy_kernel = snd_sh_dac_pcm_copy_kernel,
233 .fill_silence = snd_sh_dac_pcm_silence,
234 .mmap = snd_pcm_lib_mmap_iomem,
235 };
236
snd_sh_dac_pcm(struct snd_sh_dac * chip,int device)237 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
238 {
239 int err;
240 struct snd_pcm *pcm;
241
242 /* device should be always 0 for us */
243 err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
244 if (err < 0)
245 return err;
246
247 pcm->private_data = chip;
248 strcpy(pcm->name, "SH_DAC PCM");
249 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
250
251 /* buffer size=48K */
252 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
253 NULL, 48 * 1024, 48 * 1024);
254
255 return 0;
256 }
257 /* END OF PCM INTERFACE */
258
259
260 /* driver .remove -- destructor */
snd_sh_dac_remove(struct platform_device * devptr)261 static int snd_sh_dac_remove(struct platform_device *devptr)
262 {
263 snd_card_free(platform_get_drvdata(devptr));
264 return 0;
265 }
266
267 /* free -- it has been defined by create */
snd_sh_dac_free(struct snd_sh_dac * chip)268 static int snd_sh_dac_free(struct snd_sh_dac *chip)
269 {
270 /* release the data */
271 kfree(chip->data_buffer);
272 kfree(chip);
273
274 return 0;
275 }
276
snd_sh_dac_dev_free(struct snd_device * device)277 static int snd_sh_dac_dev_free(struct snd_device *device)
278 {
279 struct snd_sh_dac *chip = device->device_data;
280
281 return snd_sh_dac_free(chip);
282 }
283
sh_dac_audio_timer(struct hrtimer * handle)284 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
285 {
286 struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
287 hrtimer);
288 struct snd_pcm_runtime *runtime = chip->substream->runtime;
289 ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
290
291 if (!chip->empty) {
292 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
293 chip->buffer_begin++;
294
295 chip->processed++;
296 if (chip->processed >= b_ps) {
297 chip->processed -= b_ps;
298 snd_pcm_period_elapsed(chip->substream);
299 }
300
301 if (chip->buffer_begin == (chip->data_buffer +
302 chip->buffer_size - 1))
303 chip->buffer_begin = chip->data_buffer;
304
305 if (chip->buffer_begin == chip->buffer_end)
306 chip->empty = 1;
307
308 }
309
310 if (!chip->empty)
311 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
312 HRTIMER_MODE_REL);
313
314 return HRTIMER_NORESTART;
315 }
316
317 /* create -- chip-specific constructor for the cards components */
snd_sh_dac_create(struct snd_card * card,struct platform_device * devptr,struct snd_sh_dac ** rchip)318 static int snd_sh_dac_create(struct snd_card *card,
319 struct platform_device *devptr,
320 struct snd_sh_dac **rchip)
321 {
322 struct snd_sh_dac *chip;
323 int err;
324
325 static const struct snd_device_ops ops = {
326 .dev_free = snd_sh_dac_dev_free,
327 };
328
329 *rchip = NULL;
330
331 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
332 if (chip == NULL)
333 return -ENOMEM;
334
335 chip->card = card;
336
337 hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
338 chip->hrtimer.function = sh_dac_audio_timer;
339
340 dac_audio_reset(chip);
341 chip->rate = 8000;
342 dac_audio_set_rate(chip);
343
344 chip->pdata = devptr->dev.platform_data;
345
346 chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
347 if (chip->data_buffer == NULL) {
348 kfree(chip);
349 return -ENOMEM;
350 }
351
352 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
353 if (err < 0) {
354 snd_sh_dac_free(chip);
355 return err;
356 }
357
358 *rchip = chip;
359
360 return 0;
361 }
362
363 /* driver .probe -- constructor */
snd_sh_dac_probe(struct platform_device * devptr)364 static int snd_sh_dac_probe(struct platform_device *devptr)
365 {
366 struct snd_sh_dac *chip;
367 struct snd_card *card;
368 int err;
369
370 err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
371 if (err < 0) {
372 snd_printk(KERN_ERR "cannot allocate the card\n");
373 return err;
374 }
375
376 err = snd_sh_dac_create(card, devptr, &chip);
377 if (err < 0)
378 goto probe_error;
379
380 err = snd_sh_dac_pcm(chip, 0);
381 if (err < 0)
382 goto probe_error;
383
384 strcpy(card->driver, "snd_sh_dac");
385 strcpy(card->shortname, "SuperH DAC audio driver");
386 printk(KERN_INFO "%s %s", card->longname, card->shortname);
387
388 err = snd_card_register(card);
389 if (err < 0)
390 goto probe_error;
391
392 snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
393
394 platform_set_drvdata(devptr, card);
395 return 0;
396
397 probe_error:
398 snd_card_free(card);
399 return err;
400 }
401
402 /*
403 * "driver" definition
404 */
405 static struct platform_driver sh_dac_driver = {
406 .probe = snd_sh_dac_probe,
407 .remove = snd_sh_dac_remove,
408 .driver = {
409 .name = "dac_audio",
410 },
411 };
412
413 module_platform_driver(sh_dac_driver);
414