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
25MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
26MODULE_DESCRIPTION("SuperH DAC audio driver");
27MODULE_LICENSE("GPL");
28MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
29
30/* Module Parameters */
31static int index = SNDRV_DEFAULT_IDX1;
32static char *id = SNDRV_DEFAULT_STR1;
33module_param(index, int, 0444);
34MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
35module_param(id, charp, 0444);
36MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
37
38/* main struct */
39struct 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
54static 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
60static void dac_audio_stop_timer(struct snd_sh_dac *chip)
61{
62	hrtimer_cancel(&chip->hrtimer);
63}
64
65static 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
73static 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
81static 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
99static 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
116static 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
128static 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
139static 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
160static 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
179static 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
197static 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
215static
216snd_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 */
225static 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
237static 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 */
261static 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 */
268static 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
277static 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
284static 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 */
318static 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 */
364static 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
397probe_error:
398	snd_card_free(card);
399	return err;
400}
401
402/*
403 * "driver" definition
404 */
405static 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
413module_platform_driver(sh_dac_driver);
414