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(timer: &chip->hrtimer, tim: chip->wakeups_per_second,
56 mode: HRTIMER_MODE_REL);
57}
58
59static void dac_audio_stop_timer(struct snd_sh_dac *chip)
60{
61 hrtimer_cancel(timer: &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(dst: chip->data_buffer + pos, iter: 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(card: chip->card, id: "SH_DAC PCM", device, playback_count: 1, capture_count: 0, rpcm: &pcm);
224 if (err < 0)
225 return err;
226
227 pcm->private_data = chip;
228 strcpy(p: pcm->name, q: "SH_DAC PCM");
229 snd_pcm_set_ops(pcm, direction: SNDRV_PCM_STREAM_PLAYBACK, ops: &snd_sh_dac_pcm_ops);
230
231 /* buffer size=48K */
232 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
233 NULL, size: 48 * 1024, max: 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(card: platform_get_drvdata(pdev: 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(objp: chip->data_buffer);
251 kfree(objp: 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, size: 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(substream: 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(timer: &chip->hrtimer, tim: chip->wakeups_per_second,
291 mode: 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(size: sizeof(*chip), GFP_KERNEL);
311 if (chip == NULL)
312 return -ENOMEM;
313
314 chip->card = card;
315
316 hrtimer_init(timer: &chip->hrtimer, CLOCK_MONOTONIC, mode: 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(size: chip->pdata->buffer_size, GFP_KERNEL);
326 if (chip->data_buffer == NULL) {
327 kfree(objp: chip);
328 return -ENOMEM;
329 }
330
331 err = snd_device_new(card, type: SNDRV_DEV_LOWLEVEL, device_data: chip, ops: &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(parent: &devptr->dev, idx: index, xid: id, THIS_MODULE, extra_size: 0, card_ret: &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, rchip: &chip);
356 if (err < 0)
357 goto probe_error;
358
359 err = snd_sh_dac_pcm(chip, device: 0);
360 if (err < 0)
361 goto probe_error;
362
363 strcpy(p: card->driver, q: "snd_sh_dac");
364 strcpy(p: card->shortname, q: "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(pdev: devptr, data: 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

source code of linux/sound/sh/sh_dac_audio.c