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");
28
29/* Module Parameters */
30static int index = SNDRV_DEFAULT_IDX1;
31static char *id = SNDRV_DEFAULT_STR1;
32module_param(index, int, 0444);
33MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
34module_param(id, charp, 0444);
35MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
36
37/* main struct */
38struct 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
53static 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
59static void dac_audio_stop_timer(struct snd_sh_dac *chip)
60{
61	hrtimer_cancel(&chip->hrtimer);
62}
63
64static 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
72static 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
80static 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
98static 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
115static 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
127static 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
138static 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
159static 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
178static 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
196static
197snd_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 */
206static 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
217static 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 */
241static 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 */
247static 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
256static 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
263static 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 */
297static 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 */
343static 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
376probe_error:
377	snd_card_free(card);
378	return err;
379}
380
381/*
382 * "driver" definition
383 */
384static 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
392module_platform_driver(sh_dac_driver);
393