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
dac_audio_start_timer(struct snd_sh_dac * chip)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
dac_audio_stop_timer(struct snd_sh_dac * chip)59 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
60 {
61 hrtimer_cancel(&chip->hrtimer);
62 }
63
dac_audio_reset(struct snd_sh_dac * chip)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
dac_audio_set_rate(struct snd_sh_dac * chip)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
snd_sh_dac_pcm_open(struct snd_pcm_substream * substream)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
snd_sh_dac_pcm_close(struct snd_pcm_substream * substream)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
snd_sh_dac_pcm_prepare(struct snd_pcm_substream * substream)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
snd_sh_dac_pcm_trigger(struct snd_pcm_substream * substream,int cmd)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
snd_sh_dac_pcm_copy(struct snd_pcm_substream * substream,int channel,unsigned long pos,struct iov_iter * src,unsigned long count)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(chip->data_buffer + pos, count, 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
snd_sh_dac_pcm_silence(struct snd_pcm_substream * substream,int channel,unsigned long pos,unsigned long count)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(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
snd_sh_dac_pcm_pointer(struct snd_pcm_substream * substream)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 };
215
snd_sh_dac_pcm(struct snd_sh_dac * chip,int device)216 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
217 {
218 int err;
219 struct snd_pcm *pcm;
220
221 /* device should be always 0 for us */
222 err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
223 if (err < 0)
224 return err;
225
226 pcm->private_data = chip;
227 strcpy(pcm->name, "SH_DAC PCM");
228 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
229
230 /* buffer size=48K */
231 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
232 NULL, 48 * 1024, 48 * 1024);
233
234 return 0;
235 }
236 /* END OF PCM INTERFACE */
237
238
239 /* driver .remove -- destructor */
snd_sh_dac_remove(struct platform_device * devptr)240 static void snd_sh_dac_remove(struct platform_device *devptr)
241 {
242 snd_card_free(platform_get_drvdata(devptr));
243 }
244
245 /* free -- it has been defined by create */
snd_sh_dac_free(struct snd_sh_dac * chip)246 static int snd_sh_dac_free(struct snd_sh_dac *chip)
247 {
248 /* release the data */
249 kfree(chip->data_buffer);
250 kfree(chip);
251
252 return 0;
253 }
254
snd_sh_dac_dev_free(struct snd_device * device)255 static int snd_sh_dac_dev_free(struct snd_device *device)
256 {
257 struct snd_sh_dac *chip = device->device_data;
258
259 return snd_sh_dac_free(chip);
260 }
261
sh_dac_audio_timer(struct hrtimer * handle)262 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
263 {
264 struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
265 hrtimer);
266 struct snd_pcm_runtime *runtime = chip->substream->runtime;
267 ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
268
269 if (!chip->empty) {
270 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
271 chip->buffer_begin++;
272
273 chip->processed++;
274 if (chip->processed >= b_ps) {
275 chip->processed -= b_ps;
276 snd_pcm_period_elapsed(chip->substream);
277 }
278
279 if (chip->buffer_begin == (chip->data_buffer +
280 chip->buffer_size - 1))
281 chip->buffer_begin = chip->data_buffer;
282
283 if (chip->buffer_begin == chip->buffer_end)
284 chip->empty = 1;
285
286 }
287
288 if (!chip->empty)
289 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
290 HRTIMER_MODE_REL);
291
292 return HRTIMER_NORESTART;
293 }
294
295 /* create -- chip-specific constructor for the cards components */
snd_sh_dac_create(struct snd_card * card,struct platform_device * devptr,struct snd_sh_dac ** rchip)296 static int snd_sh_dac_create(struct snd_card *card,
297 struct platform_device *devptr,
298 struct snd_sh_dac **rchip)
299 {
300 struct snd_sh_dac *chip;
301 int err;
302
303 static const struct snd_device_ops ops = {
304 .dev_free = snd_sh_dac_dev_free,
305 };
306
307 *rchip = NULL;
308
309 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
310 if (chip == NULL)
311 return -ENOMEM;
312
313 chip->card = card;
314
315 hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
316 chip->hrtimer.function = sh_dac_audio_timer;
317
318 dac_audio_reset(chip);
319 chip->rate = 8000;
320 dac_audio_set_rate(chip);
321
322 chip->pdata = devptr->dev.platform_data;
323
324 chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
325 if (chip->data_buffer == NULL) {
326 kfree(chip);
327 return -ENOMEM;
328 }
329
330 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
331 if (err < 0) {
332 snd_sh_dac_free(chip);
333 return err;
334 }
335
336 *rchip = chip;
337
338 return 0;
339 }
340
341 /* driver .probe -- constructor */
snd_sh_dac_probe(struct platform_device * devptr)342 static int snd_sh_dac_probe(struct platform_device *devptr)
343 {
344 struct snd_sh_dac *chip;
345 struct snd_card *card;
346 int err;
347
348 err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
349 if (err < 0) {
350 snd_printk(KERN_ERR "cannot allocate the card\n");
351 return err;
352 }
353
354 err = snd_sh_dac_create(card, devptr, &chip);
355 if (err < 0)
356 goto probe_error;
357
358 err = snd_sh_dac_pcm(chip, 0);
359 if (err < 0)
360 goto probe_error;
361
362 strcpy(card->driver, "snd_sh_dac");
363 strcpy(card->shortname, "SuperH DAC audio driver");
364 printk(KERN_INFO "%s %s", card->longname, card->shortname);
365
366 err = snd_card_register(card);
367 if (err < 0)
368 goto probe_error;
369
370 snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
371
372 platform_set_drvdata(devptr, card);
373 return 0;
374
375 probe_error:
376 snd_card_free(card);
377 return err;
378 }
379
380 /*
381 * "driver" definition
382 */
383 static struct platform_driver sh_dac_driver = {
384 .probe = snd_sh_dac_probe,
385 .remove_new = snd_sh_dac_remove,
386 .driver = {
387 .name = "dac_audio",
388 },
389 };
390
391 module_platform_driver(sh_dac_driver);
392