xref: /openbmc/linux/sound/sh/sh_dac_audio.c (revision 2f432f47)
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 
29 /* Module Parameters */
30 static int index = SNDRV_DEFAULT_IDX1;
31 static char *id = SNDRV_DEFAULT_STR1;
32 module_param(index, int, 0444);
33 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
34 module_param(id, charp, 0444);
35 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
36 
37 /* main struct */
38 struct snd_sh_dac {
39 	struct snd_card *card;
40 	struct snd_pcm_substream *substream;
41 	struct hrtimer hrtimer;
42 	ktime_t wakeups_per_second;
43 
44 	int rate;
45 	int empty;
46 	char *data_buffer, *buffer_begin, *buffer_end;
47 	int processed; /* bytes proccesed, to compare with period_size */
48 	int buffer_size;
49 	struct dac_audio_pdata *pdata;
50 };
51 
52 
dac_audio_start_timer(struct snd_sh_dac * chip)53 static void dac_audio_start_timer(struct snd_sh_dac *chip)
54 {
55 	hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
56 		      HRTIMER_MODE_REL);
57 }
58 
dac_audio_stop_timer(struct snd_sh_dac * chip)59 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
60 {
61 	hrtimer_cancel(&chip->hrtimer);
62 }
63 
dac_audio_reset(struct snd_sh_dac * chip)64 static void dac_audio_reset(struct snd_sh_dac *chip)
65 {
66 	dac_audio_stop_timer(chip);
67 	chip->buffer_begin = chip->buffer_end = chip->data_buffer;
68 	chip->processed = 0;
69 	chip->empty = 1;
70 }
71 
dac_audio_set_rate(struct snd_sh_dac * chip)72 static void dac_audio_set_rate(struct snd_sh_dac *chip)
73 {
74 	chip->wakeups_per_second = 1000000000 / chip->rate;
75 }
76 
77 
78 /* PCM INTERFACE */
79 
80 static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
81 	.info			= (SNDRV_PCM_INFO_MMAP |
82 					SNDRV_PCM_INFO_MMAP_VALID |
83 					SNDRV_PCM_INFO_INTERLEAVED |
84 					SNDRV_PCM_INFO_HALF_DUPLEX),
85 	.formats		= SNDRV_PCM_FMTBIT_U8,
86 	.rates			= SNDRV_PCM_RATE_8000,
87 	.rate_min		= 8000,
88 	.rate_max		= 8000,
89 	.channels_min		= 1,
90 	.channels_max		= 1,
91 	.buffer_bytes_max	= (48*1024),
92 	.period_bytes_min	= 1,
93 	.period_bytes_max	= (48*1024),
94 	.periods_min		= 1,
95 	.periods_max		= 1024,
96 };
97 
snd_sh_dac_pcm_open(struct snd_pcm_substream * substream)98 static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
99 {
100 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
101 	struct snd_pcm_runtime *runtime = substream->runtime;
102 
103 	runtime->hw = snd_sh_dac_pcm_hw;
104 
105 	chip->substream = substream;
106 	chip->buffer_begin = chip->buffer_end = chip->data_buffer;
107 	chip->processed = 0;
108 	chip->empty = 1;
109 
110 	chip->pdata->start(chip->pdata);
111 
112 	return 0;
113 }
114 
snd_sh_dac_pcm_close(struct snd_pcm_substream * substream)115 static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
116 {
117 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
118 
119 	chip->substream = NULL;
120 
121 	dac_audio_stop_timer(chip);
122 	chip->pdata->stop(chip->pdata);
123 
124 	return 0;
125 }
126 
snd_sh_dac_pcm_prepare(struct snd_pcm_substream * substream)127 static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
128 {
129 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
130 	struct snd_pcm_runtime *runtime = chip->substream->runtime;
131 
132 	chip->buffer_size = runtime->buffer_size;
133 	memset(chip->data_buffer, 0, chip->pdata->buffer_size);
134 
135 	return 0;
136 }
137 
snd_sh_dac_pcm_trigger(struct snd_pcm_substream * substream,int cmd)138 static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
139 {
140 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
141 
142 	switch (cmd) {
143 	case SNDRV_PCM_TRIGGER_START:
144 		dac_audio_start_timer(chip);
145 		break;
146 	case SNDRV_PCM_TRIGGER_STOP:
147 		chip->buffer_begin = chip->buffer_end = chip->data_buffer;
148 		chip->processed = 0;
149 		chip->empty = 1;
150 		dac_audio_stop_timer(chip);
151 		break;
152 	default:
153 		 return -EINVAL;
154 	}
155 
156 	return 0;
157 }
158 
snd_sh_dac_pcm_copy(struct snd_pcm_substream * substream,int channel,unsigned long pos,struct iov_iter * src,unsigned long count)159 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
160 			       int channel, unsigned long pos,
161 			       struct iov_iter *src, unsigned long count)
162 {
163 	/* channel is not used (interleaved data) */
164 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
165 
166 	if (copy_from_iter_toio(chip->data_buffer + pos, src, count))
167 		return -EFAULT;
168 	chip->buffer_end = chip->data_buffer + pos + count;
169 
170 	if (chip->empty) {
171 		chip->empty = 0;
172 		dac_audio_start_timer(chip);
173 	}
174 
175 	return 0;
176 }
177 
snd_sh_dac_pcm_silence(struct snd_pcm_substream * substream,int channel,unsigned long pos,unsigned long count)178 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
179 				  int channel, unsigned long pos,
180 				  unsigned long count)
181 {
182 	/* channel is not used (interleaved data) */
183 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
184 
185 	memset_io(chip->data_buffer + pos, 0, count);
186 	chip->buffer_end = chip->data_buffer + pos + count;
187 
188 	if (chip->empty) {
189 		chip->empty = 0;
190 		dac_audio_start_timer(chip);
191 	}
192 
193 	return 0;
194 }
195 
196 static
snd_sh_dac_pcm_pointer(struct snd_pcm_substream * substream)197 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
198 {
199 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
200 	int pointer = chip->buffer_begin - chip->data_buffer;
201 
202 	return pointer;
203 }
204 
205 /* pcm ops */
206 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
207 	.open		= snd_sh_dac_pcm_open,
208 	.close		= snd_sh_dac_pcm_close,
209 	.prepare	= snd_sh_dac_pcm_prepare,
210 	.trigger	= snd_sh_dac_pcm_trigger,
211 	.pointer	= snd_sh_dac_pcm_pointer,
212 	.copy		= snd_sh_dac_pcm_copy,
213 	.fill_silence	= snd_sh_dac_pcm_silence,
214 	.mmap		= snd_pcm_lib_mmap_iomem,
215 };
216 
snd_sh_dac_pcm(struct snd_sh_dac * chip,int device)217 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
218 {
219 	int err;
220 	struct snd_pcm *pcm;
221 
222 	/* device should be always 0 for us */
223 	err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
224 	if (err < 0)
225 		return err;
226 
227 	pcm->private_data = chip;
228 	strcpy(pcm->name, "SH_DAC PCM");
229 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
230 
231 	/* buffer size=48K */
232 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
233 				       NULL, 48 * 1024, 48 * 1024);
234 
235 	return 0;
236 }
237 /* END OF PCM INTERFACE */
238 
239 
240 /* driver .remove  --  destructor */
snd_sh_dac_remove(struct platform_device * devptr)241 static void snd_sh_dac_remove(struct platform_device *devptr)
242 {
243 	snd_card_free(platform_get_drvdata(devptr));
244 }
245 
246 /* free -- it has been defined by create */
snd_sh_dac_free(struct snd_sh_dac * chip)247 static int snd_sh_dac_free(struct snd_sh_dac *chip)
248 {
249 	/* release the data */
250 	kfree(chip->data_buffer);
251 	kfree(chip);
252 
253 	return 0;
254 }
255 
snd_sh_dac_dev_free(struct snd_device * device)256 static int snd_sh_dac_dev_free(struct snd_device *device)
257 {
258 	struct snd_sh_dac *chip = device->device_data;
259 
260 	return snd_sh_dac_free(chip);
261 }
262 
sh_dac_audio_timer(struct hrtimer * handle)263 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
264 {
265 	struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
266 					       hrtimer);
267 	struct snd_pcm_runtime *runtime = chip->substream->runtime;
268 	ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
269 
270 	if (!chip->empty) {
271 		sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
272 		chip->buffer_begin++;
273 
274 		chip->processed++;
275 		if (chip->processed >= b_ps) {
276 			chip->processed -= b_ps;
277 			snd_pcm_period_elapsed(chip->substream);
278 		}
279 
280 		if (chip->buffer_begin == (chip->data_buffer +
281 					   chip->buffer_size - 1))
282 			chip->buffer_begin = chip->data_buffer;
283 
284 		if (chip->buffer_begin == chip->buffer_end)
285 			chip->empty = 1;
286 
287 	}
288 
289 	if (!chip->empty)
290 		hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
291 			      HRTIMER_MODE_REL);
292 
293 	return HRTIMER_NORESTART;
294 }
295 
296 /* 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)297 static int snd_sh_dac_create(struct snd_card *card,
298 			     struct platform_device *devptr,
299 			     struct snd_sh_dac **rchip)
300 {
301 	struct snd_sh_dac *chip;
302 	int err;
303 
304 	static const struct snd_device_ops ops = {
305 		   .dev_free = snd_sh_dac_dev_free,
306 	};
307 
308 	*rchip = NULL;
309 
310 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
311 	if (chip == NULL)
312 		return -ENOMEM;
313 
314 	chip->card = card;
315 
316 	hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
317 	chip->hrtimer.function = sh_dac_audio_timer;
318 
319 	dac_audio_reset(chip);
320 	chip->rate = 8000;
321 	dac_audio_set_rate(chip);
322 
323 	chip->pdata = devptr->dev.platform_data;
324 
325 	chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
326 	if (chip->data_buffer == NULL) {
327 		kfree(chip);
328 		return -ENOMEM;
329 	}
330 
331 	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
332 	if (err < 0) {
333 		snd_sh_dac_free(chip);
334 		return err;
335 	}
336 
337 	*rchip = chip;
338 
339 	return 0;
340 }
341 
342 /* driver .probe  --  constructor */
snd_sh_dac_probe(struct platform_device * devptr)343 static int snd_sh_dac_probe(struct platform_device *devptr)
344 {
345 	struct snd_sh_dac *chip;
346 	struct snd_card *card;
347 	int err;
348 
349 	err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
350 	if (err < 0) {
351 			snd_printk(KERN_ERR "cannot allocate the card\n");
352 			return err;
353 	}
354 
355 	err = snd_sh_dac_create(card, devptr, &chip);
356 	if (err < 0)
357 		goto probe_error;
358 
359 	err = snd_sh_dac_pcm(chip, 0);
360 	if (err < 0)
361 		goto probe_error;
362 
363 	strcpy(card->driver, "snd_sh_dac");
364 	strcpy(card->shortname, "SuperH DAC audio driver");
365 	printk(KERN_INFO "%s %s", card->longname, card->shortname);
366 
367 	err = snd_card_register(card);
368 	if (err < 0)
369 		goto probe_error;
370 
371 	snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
372 
373 	platform_set_drvdata(devptr, card);
374 	return 0;
375 
376 probe_error:
377 	snd_card_free(card);
378 	return err;
379 }
380 
381 /*
382  * "driver" definition
383  */
384 static struct platform_driver sh_dac_driver = {
385 	.probe	= snd_sh_dac_probe,
386 	.remove_new = snd_sh_dac_remove,
387 	.driver = {
388 		.name = "dac_audio",
389 	},
390 };
391 
392 module_platform_driver(sh_dac_driver);
393