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,void __user * src,unsigned long count)159 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
160 			       int channel, unsigned long pos,
161 			       void __user *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_user_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 
snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream * substream,int channel,unsigned long pos,void * src,unsigned long count)178 static int snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream *substream,
179 				      int channel, unsigned long pos,
180 				      void *src, unsigned long count)
181 {
182 	/* channel is not used (interleaved data) */
183 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
184 
185 	memcpy_toio(chip->data_buffer + pos, src, 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 
snd_sh_dac_pcm_silence(struct snd_pcm_substream * substream,int channel,unsigned long pos,unsigned long count)196 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
197 				  int channel, unsigned long pos,
198 				  unsigned long count)
199 {
200 	/* channel is not used (interleaved data) */
201 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
202 
203 	memset_io(chip->data_buffer + pos, 0, count);
204 	chip->buffer_end = chip->data_buffer + pos + count;
205 
206 	if (chip->empty) {
207 		chip->empty = 0;
208 		dac_audio_start_timer(chip);
209 	}
210 
211 	return 0;
212 }
213 
214 static
snd_sh_dac_pcm_pointer(struct snd_pcm_substream * substream)215 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
216 {
217 	struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
218 	int pointer = chip->buffer_begin - chip->data_buffer;
219 
220 	return pointer;
221 }
222 
223 /* pcm ops */
224 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
225 	.open		= snd_sh_dac_pcm_open,
226 	.close		= snd_sh_dac_pcm_close,
227 	.prepare	= snd_sh_dac_pcm_prepare,
228 	.trigger	= snd_sh_dac_pcm_trigger,
229 	.pointer	= snd_sh_dac_pcm_pointer,
230 	.copy_user	= snd_sh_dac_pcm_copy,
231 	.copy_kernel	= snd_sh_dac_pcm_copy_kernel,
232 	.fill_silence	= snd_sh_dac_pcm_silence,
233 	.mmap		= snd_pcm_lib_mmap_iomem,
234 };
235 
snd_sh_dac_pcm(struct snd_sh_dac * chip,int device)236 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
237 {
238 	int err;
239 	struct snd_pcm *pcm;
240 
241 	/* device should be always 0 for us */
242 	err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
243 	if (err < 0)
244 		return err;
245 
246 	pcm->private_data = chip;
247 	strcpy(pcm->name, "SH_DAC PCM");
248 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
249 
250 	/* buffer size=48K */
251 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
252 				       NULL, 48 * 1024, 48 * 1024);
253 
254 	return 0;
255 }
256 /* END OF PCM INTERFACE */
257 
258 
259 /* driver .remove  --  destructor */
snd_sh_dac_remove(struct platform_device * devptr)260 static int snd_sh_dac_remove(struct platform_device *devptr)
261 {
262 	snd_card_free(platform_get_drvdata(devptr));
263 	return 0;
264 }
265 
266 /* free -- it has been defined by create */
snd_sh_dac_free(struct snd_sh_dac * chip)267 static int snd_sh_dac_free(struct snd_sh_dac *chip)
268 {
269 	/* release the data */
270 	kfree(chip->data_buffer);
271 	kfree(chip);
272 
273 	return 0;
274 }
275 
snd_sh_dac_dev_free(struct snd_device * device)276 static int snd_sh_dac_dev_free(struct snd_device *device)
277 {
278 	struct snd_sh_dac *chip = device->device_data;
279 
280 	return snd_sh_dac_free(chip);
281 }
282 
sh_dac_audio_timer(struct hrtimer * handle)283 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
284 {
285 	struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
286 					       hrtimer);
287 	struct snd_pcm_runtime *runtime = chip->substream->runtime;
288 	ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
289 
290 	if (!chip->empty) {
291 		sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
292 		chip->buffer_begin++;
293 
294 		chip->processed++;
295 		if (chip->processed >= b_ps) {
296 			chip->processed -= b_ps;
297 			snd_pcm_period_elapsed(chip->substream);
298 		}
299 
300 		if (chip->buffer_begin == (chip->data_buffer +
301 					   chip->buffer_size - 1))
302 			chip->buffer_begin = chip->data_buffer;
303 
304 		if (chip->buffer_begin == chip->buffer_end)
305 			chip->empty = 1;
306 
307 	}
308 
309 	if (!chip->empty)
310 		hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
311 			      HRTIMER_MODE_REL);
312 
313 	return HRTIMER_NORESTART;
314 }
315 
316 /* 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)317 static int snd_sh_dac_create(struct snd_card *card,
318 			     struct platform_device *devptr,
319 			     struct snd_sh_dac **rchip)
320 {
321 	struct snd_sh_dac *chip;
322 	int err;
323 
324 	static const struct snd_device_ops ops = {
325 		   .dev_free = snd_sh_dac_dev_free,
326 	};
327 
328 	*rchip = NULL;
329 
330 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
331 	if (chip == NULL)
332 		return -ENOMEM;
333 
334 	chip->card = card;
335 
336 	hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
337 	chip->hrtimer.function = sh_dac_audio_timer;
338 
339 	dac_audio_reset(chip);
340 	chip->rate = 8000;
341 	dac_audio_set_rate(chip);
342 
343 	chip->pdata = devptr->dev.platform_data;
344 
345 	chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
346 	if (chip->data_buffer == NULL) {
347 		kfree(chip);
348 		return -ENOMEM;
349 	}
350 
351 	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
352 	if (err < 0) {
353 		snd_sh_dac_free(chip);
354 		return err;
355 	}
356 
357 	*rchip = chip;
358 
359 	return 0;
360 }
361 
362 /* driver .probe  --  constructor */
snd_sh_dac_probe(struct platform_device * devptr)363 static int snd_sh_dac_probe(struct platform_device *devptr)
364 {
365 	struct snd_sh_dac *chip;
366 	struct snd_card *card;
367 	int err;
368 
369 	err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
370 	if (err < 0) {
371 			snd_printk(KERN_ERR "cannot allocate the card\n");
372 			return err;
373 	}
374 
375 	err = snd_sh_dac_create(card, devptr, &chip);
376 	if (err < 0)
377 		goto probe_error;
378 
379 	err = snd_sh_dac_pcm(chip, 0);
380 	if (err < 0)
381 		goto probe_error;
382 
383 	strcpy(card->driver, "snd_sh_dac");
384 	strcpy(card->shortname, "SuperH DAC audio driver");
385 	printk(KERN_INFO "%s %s", card->longname, card->shortname);
386 
387 	err = snd_card_register(card);
388 	if (err < 0)
389 		goto probe_error;
390 
391 	snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
392 
393 	platform_set_drvdata(devptr, card);
394 	return 0;
395 
396 probe_error:
397 	snd_card_free(card);
398 	return err;
399 }
400 
401 /*
402  * "driver" definition
403  */
404 static struct platform_driver sh_dac_driver = {
405 	.probe	= snd_sh_dac_probe,
406 	.remove = snd_sh_dac_remove,
407 	.driver = {
408 		.name = "dac_audio",
409 	},
410 };
411 
412 module_platform_driver(sh_dac_driver);
413