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
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
59 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
60 {
61 hrtimer_cancel(&chip->hrtimer);
62 }
63
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
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
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
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
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
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
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
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
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
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 */
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 */
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
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
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 */
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 */
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
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.