1/*
2 * sh_dac_audio.c - SuperH DAC audio driver for ALSA
3 *
4 * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
5 *
6 *
7 * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
8 *
9 *   This program is free software; you can redistribute it and/or modify
10 *   it under the terms of the GNU General Public License as published by
11 *   the Free Software Foundation; either version 2 of the License, or
12 *   (at your option) any later version.
13 *
14 *   This program is distributed in the hope that it will be useful,
15 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
16 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 *   GNU General Public License for more details.
18 *
19 *   You should have received a copy of the GNU General Public License
20 *   along with this program; if not, write to the Free Software
21 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
22 *
23 */
24
25#include <linux/hrtimer.h>
26#include <linux/interrupt.h>
27#include <linux/io.h>
28#include <linux/platform_device.h>
29#include <linux/slab.h>
30#include <linux/module.h>
31#include <sound/core.h>
32#include <sound/initval.h>
33#include <sound/pcm.h>
34#include <sound/sh_dac_audio.h>
35#include <asm/clock.h>
36#include <asm/hd64461.h>
37#include <mach/hp6xx.h>
38#include <cpu/dac.h>
39
40MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
41MODULE_DESCRIPTION("SuperH DAC audio driver");
42MODULE_LICENSE("GPL");
43MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
44
45/* Module Parameters */
46static int index = SNDRV_DEFAULT_IDX1;
47static char *id = SNDRV_DEFAULT_STR1;
48module_param(index, int, 0444);
49MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
50module_param(id, charp, 0444);
51MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
52
53/* main struct */
54struct snd_sh_dac {
55	struct snd_card *card;
56	struct snd_pcm_substream *substream;
57	struct hrtimer hrtimer;
58	ktime_t wakeups_per_second;
59
60	int rate;
61	int empty;
62	char *data_buffer, *buffer_begin, *buffer_end;
63	int processed; /* bytes proccesed, to compare with period_size */
64	int buffer_size;
65	struct dac_audio_pdata *pdata;
66};
67
68
69static void dac_audio_start_timer(struct snd_sh_dac *chip)
70{
71	hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
72		      HRTIMER_MODE_REL);
73}
74
75static void dac_audio_stop_timer(struct snd_sh_dac *chip)
76{
77	hrtimer_cancel(&chip->hrtimer);
78}
79
80static void dac_audio_reset(struct snd_sh_dac *chip)
81{
82	dac_audio_stop_timer(chip);
83	chip->buffer_begin = chip->buffer_end = chip->data_buffer;
84	chip->processed = 0;
85	chip->empty = 1;
86}
87
88static void dac_audio_set_rate(struct snd_sh_dac *chip)
89{
90	chip->wakeups_per_second = ktime_set(0, 1000000000 / chip->rate);
91}
92
93
94/* PCM INTERFACE */
95
96static struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
97	.info			= (SNDRV_PCM_INFO_MMAP |
98					SNDRV_PCM_INFO_MMAP_VALID |
99					SNDRV_PCM_INFO_INTERLEAVED |
100					SNDRV_PCM_INFO_HALF_DUPLEX),
101	.formats		= SNDRV_PCM_FMTBIT_U8,
102	.rates			= SNDRV_PCM_RATE_8000,
103	.rate_min		= 8000,
104	.rate_max		= 8000,
105	.channels_min		= 1,
106	.channels_max		= 1,
107	.buffer_bytes_max	= (48*1024),
108	.period_bytes_min	= 1,
109	.period_bytes_max	= (48*1024),
110	.periods_min		= 1,
111	.periods_max		= 1024,
112};
113
114static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
115{
116	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
117	struct snd_pcm_runtime *runtime = substream->runtime;
118
119	runtime->hw = snd_sh_dac_pcm_hw;
120
121	chip->substream = substream;
122	chip->buffer_begin = chip->buffer_end = chip->data_buffer;
123	chip->processed = 0;
124	chip->empty = 1;
125
126	chip->pdata->start(chip->pdata);
127
128	return 0;
129}
130
131static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
132{
133	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
134
135	chip->substream = NULL;
136
137	dac_audio_stop_timer(chip);
138	chip->pdata->stop(chip->pdata);
139
140	return 0;
141}
142
143static int snd_sh_dac_pcm_hw_params(struct snd_pcm_substream *substream,
144				struct snd_pcm_hw_params *hw_params)
145{
146	return snd_pcm_lib_malloc_pages(substream,
147			params_buffer_bytes(hw_params));
148}
149
150static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
151{
152	return snd_pcm_lib_free_pages(substream);
153}
154
155static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
156{
157	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
158	struct snd_pcm_runtime *runtime = chip->substream->runtime;
159
160	chip->buffer_size = runtime->buffer_size;
161	memset(chip->data_buffer, 0, chip->pdata->buffer_size);
162
163	return 0;
164}
165
166static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
167{
168	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
169
170	switch (cmd) {
171	case SNDRV_PCM_TRIGGER_START:
172		dac_audio_start_timer(chip);
173		break;
174	case SNDRV_PCM_TRIGGER_STOP:
175		chip->buffer_begin = chip->buffer_end = chip->data_buffer;
176		chip->processed = 0;
177		chip->empty = 1;
178		dac_audio_stop_timer(chip);
179		break;
180	default:
181		 return -EINVAL;
182	}
183
184	return 0;
185}
186
187static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream, int channel,
188	snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
189{
190	/* channel is not used (interleaved data) */
191	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
192	struct snd_pcm_runtime *runtime = substream->runtime;
193	ssize_t b_count = frames_to_bytes(runtime , count);
194	ssize_t b_pos = frames_to_bytes(runtime , pos);
195
196	if (count < 0)
197		return -EINVAL;
198
199	if (!count)
200		return 0;
201
202	memcpy_toio(chip->data_buffer + b_pos, src, b_count);
203	chip->buffer_end = chip->data_buffer + b_pos + b_count;
204
205	if (chip->empty) {
206		chip->empty = 0;
207		dac_audio_start_timer(chip);
208	}
209
210	return 0;
211}
212
213static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
214				  int channel, snd_pcm_uframes_t pos,
215				  snd_pcm_uframes_t count)
216{
217	/* channel is not used (interleaved data) */
218	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
219	struct snd_pcm_runtime *runtime = substream->runtime;
220	ssize_t b_count = frames_to_bytes(runtime , count);
221	ssize_t b_pos = frames_to_bytes(runtime , pos);
222
223	if (count < 0)
224		return -EINVAL;
225
226	if (!count)
227		return 0;
228
229	memset_io(chip->data_buffer + b_pos, 0, b_count);
230	chip->buffer_end = chip->data_buffer + b_pos + b_count;
231
232	if (chip->empty) {
233		chip->empty = 0;
234		dac_audio_start_timer(chip);
235	}
236
237	return 0;
238}
239
240static
241snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
242{
243	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
244	int pointer = chip->buffer_begin - chip->data_buffer;
245
246	return pointer;
247}
248
249/* pcm ops */
250static struct snd_pcm_ops snd_sh_dac_pcm_ops = {
251	.open		= snd_sh_dac_pcm_open,
252	.close		= snd_sh_dac_pcm_close,
253	.ioctl		= snd_pcm_lib_ioctl,
254	.hw_params	= snd_sh_dac_pcm_hw_params,
255	.hw_free	= snd_sh_dac_pcm_hw_free,
256	.prepare	= snd_sh_dac_pcm_prepare,
257	.trigger	= snd_sh_dac_pcm_trigger,
258	.pointer	= snd_sh_dac_pcm_pointer,
259	.copy		= snd_sh_dac_pcm_copy,
260	.silence	= snd_sh_dac_pcm_silence,
261	.mmap		= snd_pcm_lib_mmap_iomem,
262};
263
264static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
265{
266	int err;
267	struct snd_pcm *pcm;
268
269	/* device should be always 0 for us */
270	err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
271	if (err < 0)
272		return err;
273
274	pcm->private_data = chip;
275	strcpy(pcm->name, "SH_DAC PCM");
276	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
277
278	/* buffer size=48K */
279	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
280					  snd_dma_continuous_data(GFP_KERNEL),
281							48 * 1024,
282							48 * 1024);
283
284	return 0;
285}
286/* END OF PCM INTERFACE */
287
288
289/* driver .remove  --  destructor */
290static int snd_sh_dac_remove(struct platform_device *devptr)
291{
292	snd_card_free(platform_get_drvdata(devptr));
293	return 0;
294}
295
296/* free -- it has been defined by create */
297static int snd_sh_dac_free(struct snd_sh_dac *chip)
298{
299	/* release the data */
300	kfree(chip->data_buffer);
301	kfree(chip);
302
303	return 0;
304}
305
306static int snd_sh_dac_dev_free(struct snd_device *device)
307{
308	struct snd_sh_dac *chip = device->device_data;
309
310	return snd_sh_dac_free(chip);
311}
312
313static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
314{
315	struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
316					       hrtimer);
317	struct snd_pcm_runtime *runtime = chip->substream->runtime;
318	ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
319
320	if (!chip->empty) {
321		sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
322		chip->buffer_begin++;
323
324		chip->processed++;
325		if (chip->processed >= b_ps) {
326			chip->processed -= b_ps;
327			snd_pcm_period_elapsed(chip->substream);
328		}
329
330		if (chip->buffer_begin == (chip->data_buffer +
331					   chip->buffer_size - 1))
332			chip->buffer_begin = chip->data_buffer;
333
334		if (chip->buffer_begin == chip->buffer_end)
335			chip->empty = 1;
336
337	}
338
339	if (!chip->empty)
340		hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
341			      HRTIMER_MODE_REL);
342
343	return HRTIMER_NORESTART;
344}
345
346/* create  --  chip-specific constructor for the cards components */
347static int snd_sh_dac_create(struct snd_card *card,
348			     struct platform_device *devptr,
349			     struct snd_sh_dac **rchip)
350{
351	struct snd_sh_dac *chip;
352	int err;
353
354	static struct snd_device_ops ops = {
355		   .dev_free = snd_sh_dac_dev_free,
356	};
357
358	*rchip = NULL;
359
360	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
361	if (chip == NULL)
362		return -ENOMEM;
363
364	chip->card = card;
365
366	hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
367	chip->hrtimer.function = sh_dac_audio_timer;
368
369	dac_audio_reset(chip);
370	chip->rate = 8000;
371	dac_audio_set_rate(chip);
372
373	chip->pdata = devptr->dev.platform_data;
374
375	chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
376	if (chip->data_buffer == NULL) {
377		kfree(chip);
378		return -ENOMEM;
379	}
380
381	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
382	if (err < 0) {
383		snd_sh_dac_free(chip);
384		return err;
385	}
386
387	*rchip = chip;
388
389	return 0;
390}
391
392/* driver .probe  --  constructor */
393static int snd_sh_dac_probe(struct platform_device *devptr)
394{
395	struct snd_sh_dac *chip;
396	struct snd_card *card;
397	int err;
398
399	err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
400	if (err < 0) {
401			snd_printk(KERN_ERR "cannot allocate the card\n");
402			return err;
403	}
404
405	err = snd_sh_dac_create(card, devptr, &chip);
406	if (err < 0)
407		goto probe_error;
408
409	err = snd_sh_dac_pcm(chip, 0);
410	if (err < 0)
411		goto probe_error;
412
413	strcpy(card->driver, "snd_sh_dac");
414	strcpy(card->shortname, "SuperH DAC audio driver");
415	printk(KERN_INFO "%s %s", card->longname, card->shortname);
416
417	err = snd_card_register(card);
418	if (err < 0)
419		goto probe_error;
420
421	snd_printk("ALSA driver for SuperH DAC audio");
422
423	platform_set_drvdata(devptr, card);
424	return 0;
425
426probe_error:
427	snd_card_free(card);
428	return err;
429}
430
431/*
432 * "driver" definition
433 */
434static struct platform_driver sh_dac_driver = {
435	.probe	= snd_sh_dac_probe,
436	.remove = snd_sh_dac_remove,
437	.driver = {
438		.name = "dac_audio",
439	},
440};
441
442module_platform_driver(sh_dac_driver);
443