1 /*
2  * atmel-pcm.c  --  ALSA PCM interface for the Atmel atmel SoC.
3  *
4  *  Copyright (C) 2005 SAN People
5  *  Copyright (C) 2008 Atmel
6  *
7  * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
8  *
9  * Based on at91-pcm. by:
10  * Frank Mandarino <fmandarino@endrelia.com>
11  * Copyright 2006 Endrelia Technologies Inc.
12  *
13  * Based on pxa2xx-pcm.c by:
14  *
15  * Author:	Nicolas Pitre
16  * Created:	Nov 30, 2004
17  * Copyright:	(C) 2004 MontaVista Software, Inc.
18  *
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License as published by
21  * the Free Software Foundation; either version 2 of the License, or
22  * (at your option) any later version.
23  *
24  * This program is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with this program; if not, write to the Free Software
31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
32  */
33 
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/platform_device.h>
37 #include <linux/slab.h>
38 #include <linux/dma-mapping.h>
39 #include <linux/atmel_pdc.h>
40 #include <linux/atmel-ssc.h>
41 
42 #include <sound/core.h>
43 #include <sound/pcm.h>
44 #include <sound/pcm_params.h>
45 #include <sound/soc.h>
46 
47 #include "atmel-pcm.h"
48 
49 
50 /*--------------------------------------------------------------------------*\
51  * Hardware definition
52 \*--------------------------------------------------------------------------*/
53 /* TODO: These values were taken from the AT91 platform driver, check
54  *	 them against real values for AT32
55  */
56 static const struct snd_pcm_hardware atmel_pcm_hardware = {
57 	.info			= SNDRV_PCM_INFO_MMAP |
58 				  SNDRV_PCM_INFO_MMAP_VALID |
59 				  SNDRV_PCM_INFO_INTERLEAVED |
60 				  SNDRV_PCM_INFO_PAUSE,
61 	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
62 	.period_bytes_min	= 32,
63 	.period_bytes_max	= 8192,
64 	.periods_min		= 2,
65 	.periods_max		= 1024,
66 	.buffer_bytes_max	= 32 * 1024,
67 };
68 
69 
70 /*--------------------------------------------------------------------------*\
71  * Data types
72 \*--------------------------------------------------------------------------*/
73 struct atmel_runtime_data {
74 	struct atmel_pcm_dma_params *params;
75 	dma_addr_t dma_buffer;		/* physical address of dma buffer */
76 	dma_addr_t dma_buffer_end;	/* first address beyond DMA buffer */
77 	size_t period_size;
78 
79 	dma_addr_t period_ptr;		/* physical address of next period */
80 
81 	/* PDC register save */
82 	u32 pdc_xpr_save;
83 	u32 pdc_xcr_save;
84 	u32 pdc_xnpr_save;
85 	u32 pdc_xncr_save;
86 };
87 
88 
89 /*--------------------------------------------------------------------------*\
90  * Helper functions
91 \*--------------------------------------------------------------------------*/
atmel_pcm_preallocate_dma_buffer(struct snd_pcm * pcm,int stream)92 static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
93 	int stream)
94 {
95 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
96 	struct snd_dma_buffer *buf = &substream->dma_buffer;
97 	size_t size = atmel_pcm_hardware.buffer_bytes_max;
98 
99 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
100 	buf->dev.dev = pcm->card->dev;
101 	buf->private_data = NULL;
102 	buf->area = dma_alloc_coherent(pcm->card->dev, size,
103 					  &buf->addr, GFP_KERNEL);
104 	pr_debug("atmel-pcm:"
105 		"preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
106 		(void *) buf->area,
107 		(void *) buf->addr,
108 		size);
109 
110 	if (!buf->area)
111 		return -ENOMEM;
112 
113 	buf->bytes = size;
114 	return 0;
115 }
116 /*--------------------------------------------------------------------------*\
117  * ISR
118 \*--------------------------------------------------------------------------*/
atmel_pcm_dma_irq(u32 ssc_sr,struct snd_pcm_substream * substream)119 static void atmel_pcm_dma_irq(u32 ssc_sr,
120 	struct snd_pcm_substream *substream)
121 {
122 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
123 	struct atmel_pcm_dma_params *params = prtd->params;
124 	static int count;
125 
126 	count++;
127 
128 	if (ssc_sr & params->mask->ssc_endbuf) {
129 		pr_warning("atmel-pcm: buffer %s on %s"
130 				" (SSC_SR=%#x, count=%d)\n",
131 				substream->stream == SNDRV_PCM_STREAM_PLAYBACK
132 				? "underrun" : "overrun",
133 				params->name, ssc_sr, count);
134 
135 		/* re-start the PDC */
136 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
137 			   params->mask->pdc_disable);
138 		prtd->period_ptr += prtd->period_size;
139 		if (prtd->period_ptr >= prtd->dma_buffer_end)
140 			prtd->period_ptr = prtd->dma_buffer;
141 
142 		ssc_writex(params->ssc->regs, params->pdc->xpr,
143 			   prtd->period_ptr);
144 		ssc_writex(params->ssc->regs, params->pdc->xcr,
145 			   prtd->period_size / params->pdc_xfer_size);
146 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
147 			   params->mask->pdc_enable);
148 	}
149 
150 	if (ssc_sr & params->mask->ssc_endx) {
151 		/* Load the PDC next pointer and counter registers */
152 		prtd->period_ptr += prtd->period_size;
153 		if (prtd->period_ptr >= prtd->dma_buffer_end)
154 			prtd->period_ptr = prtd->dma_buffer;
155 
156 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
157 			   prtd->period_ptr);
158 		ssc_writex(params->ssc->regs, params->pdc->xncr,
159 			   prtd->period_size / params->pdc_xfer_size);
160 	}
161 
162 	snd_pcm_period_elapsed(substream);
163 }
164 
165 
166 /*--------------------------------------------------------------------------*\
167  * PCM operations
168 \*--------------------------------------------------------------------------*/
atmel_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)169 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
170 	struct snd_pcm_hw_params *params)
171 {
172 	struct snd_pcm_runtime *runtime = substream->runtime;
173 	struct atmel_runtime_data *prtd = runtime->private_data;
174 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
175 
176 	/* this may get called several times by oss emulation
177 	 * with different params */
178 
179 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
180 	runtime->dma_bytes = params_buffer_bytes(params);
181 
182 	prtd->params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
183 	prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
184 
185 	prtd->dma_buffer = runtime->dma_addr;
186 	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
187 	prtd->period_size = params_period_bytes(params);
188 
189 	pr_debug("atmel-pcm: "
190 		"hw_params: DMA for %s initialized "
191 		"(dma_bytes=%u, period_size=%u)\n",
192 		prtd->params->name,
193 		runtime->dma_bytes,
194 		prtd->period_size);
195 	return 0;
196 }
197 
atmel_pcm_hw_free(struct snd_pcm_substream * substream)198 static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
199 {
200 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
201 	struct atmel_pcm_dma_params *params = prtd->params;
202 
203 	if (params != NULL) {
204 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
205 			   params->mask->pdc_disable);
206 		prtd->params->dma_intr_handler = NULL;
207 	}
208 
209 	return 0;
210 }
211 
atmel_pcm_prepare(struct snd_pcm_substream * substream)212 static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
213 {
214 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
215 	struct atmel_pcm_dma_params *params = prtd->params;
216 
217 	ssc_writex(params->ssc->regs, SSC_IDR,
218 		   params->mask->ssc_endx | params->mask->ssc_endbuf);
219 	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
220 		   params->mask->pdc_disable);
221 	return 0;
222 }
223 
atmel_pcm_trigger(struct snd_pcm_substream * substream,int cmd)224 static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
225 	int cmd)
226 {
227 	struct snd_pcm_runtime *rtd = substream->runtime;
228 	struct atmel_runtime_data *prtd = rtd->private_data;
229 	struct atmel_pcm_dma_params *params = prtd->params;
230 	int ret = 0;
231 
232 	pr_debug("atmel-pcm:buffer_size = %ld,"
233 		"dma_area = %p, dma_bytes = %u\n",
234 		rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
235 
236 	switch (cmd) {
237 	case SNDRV_PCM_TRIGGER_START:
238 		prtd->period_ptr = prtd->dma_buffer;
239 
240 		ssc_writex(params->ssc->regs, params->pdc->xpr,
241 			   prtd->period_ptr);
242 		ssc_writex(params->ssc->regs, params->pdc->xcr,
243 			   prtd->period_size / params->pdc_xfer_size);
244 
245 		prtd->period_ptr += prtd->period_size;
246 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
247 			   prtd->period_ptr);
248 		ssc_writex(params->ssc->regs, params->pdc->xncr,
249 			   prtd->period_size / params->pdc_xfer_size);
250 
251 		pr_debug("atmel-pcm: trigger: "
252 			"period_ptr=%lx, xpr=%u, "
253 			"xcr=%u, xnpr=%u, xncr=%u\n",
254 			(unsigned long)prtd->period_ptr,
255 			ssc_readx(params->ssc->regs, params->pdc->xpr),
256 			ssc_readx(params->ssc->regs, params->pdc->xcr),
257 			ssc_readx(params->ssc->regs, params->pdc->xnpr),
258 			ssc_readx(params->ssc->regs, params->pdc->xncr));
259 
260 		ssc_writex(params->ssc->regs, SSC_IER,
261 			   params->mask->ssc_endx | params->mask->ssc_endbuf);
262 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
263 			   params->mask->pdc_enable);
264 
265 		pr_debug("sr=%u imr=%u\n",
266 			ssc_readx(params->ssc->regs, SSC_SR),
267 			ssc_readx(params->ssc->regs, SSC_IER));
268 		break;		/* SNDRV_PCM_TRIGGER_START */
269 
270 	case SNDRV_PCM_TRIGGER_STOP:
271 	case SNDRV_PCM_TRIGGER_SUSPEND:
272 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
273 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
274 			   params->mask->pdc_disable);
275 		break;
276 
277 	case SNDRV_PCM_TRIGGER_RESUME:
278 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
279 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
280 			   params->mask->pdc_enable);
281 		break;
282 
283 	default:
284 		ret = -EINVAL;
285 	}
286 
287 	return ret;
288 }
289 
atmel_pcm_pointer(struct snd_pcm_substream * substream)290 static snd_pcm_uframes_t atmel_pcm_pointer(
291 	struct snd_pcm_substream *substream)
292 {
293 	struct snd_pcm_runtime *runtime = substream->runtime;
294 	struct atmel_runtime_data *prtd = runtime->private_data;
295 	struct atmel_pcm_dma_params *params = prtd->params;
296 	dma_addr_t ptr;
297 	snd_pcm_uframes_t x;
298 
299 	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
300 	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
301 
302 	if (x == runtime->buffer_size)
303 		x = 0;
304 
305 	return x;
306 }
307 
atmel_pcm_open(struct snd_pcm_substream * substream)308 static int atmel_pcm_open(struct snd_pcm_substream *substream)
309 {
310 	struct snd_pcm_runtime *runtime = substream->runtime;
311 	struct atmel_runtime_data *prtd;
312 	int ret = 0;
313 
314 	snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
315 
316 	/* ensure that buffer size is a multiple of period size */
317 	ret = snd_pcm_hw_constraint_integer(runtime,
318 						SNDRV_PCM_HW_PARAM_PERIODS);
319 	if (ret < 0)
320 		goto out;
321 
322 	prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
323 	if (prtd == NULL) {
324 		ret = -ENOMEM;
325 		goto out;
326 	}
327 	runtime->private_data = prtd;
328 
329  out:
330 	return ret;
331 }
332 
atmel_pcm_close(struct snd_pcm_substream * substream)333 static int atmel_pcm_close(struct snd_pcm_substream *substream)
334 {
335 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
336 
337 	kfree(prtd);
338 	return 0;
339 }
340 
atmel_pcm_mmap(struct snd_pcm_substream * substream,struct vm_area_struct * vma)341 static int atmel_pcm_mmap(struct snd_pcm_substream *substream,
342 	struct vm_area_struct *vma)
343 {
344 	return remap_pfn_range(vma, vma->vm_start,
345 		       substream->dma_buffer.addr >> PAGE_SHIFT,
346 		       vma->vm_end - vma->vm_start, vma->vm_page_prot);
347 }
348 
349 static struct snd_pcm_ops atmel_pcm_ops = {
350 	.open		= atmel_pcm_open,
351 	.close		= atmel_pcm_close,
352 	.ioctl		= snd_pcm_lib_ioctl,
353 	.hw_params	= atmel_pcm_hw_params,
354 	.hw_free	= atmel_pcm_hw_free,
355 	.prepare	= atmel_pcm_prepare,
356 	.trigger	= atmel_pcm_trigger,
357 	.pointer	= atmel_pcm_pointer,
358 	.mmap		= atmel_pcm_mmap,
359 };
360 
361 
362 /*--------------------------------------------------------------------------*\
363  * ASoC platform driver
364 \*--------------------------------------------------------------------------*/
365 static u64 atmel_pcm_dmamask = 0xffffffff;
366 
atmel_pcm_new(struct snd_soc_pcm_runtime * rtd)367 static int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
368 {
369 	struct snd_card *card = rtd->card->snd_card;
370 	struct snd_pcm *pcm = rtd->pcm;
371 	int ret = 0;
372 
373 	if (!card->dev->dma_mask)
374 		card->dev->dma_mask = &atmel_pcm_dmamask;
375 	if (!card->dev->coherent_dma_mask)
376 		card->dev->coherent_dma_mask = 0xffffffff;
377 
378 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
379 		ret = atmel_pcm_preallocate_dma_buffer(pcm,
380 			SNDRV_PCM_STREAM_PLAYBACK);
381 		if (ret)
382 			goto out;
383 	}
384 
385 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
386 		pr_debug("atmel-pcm:"
387 				"Allocating PCM capture DMA buffer\n");
388 		ret = atmel_pcm_preallocate_dma_buffer(pcm,
389 			SNDRV_PCM_STREAM_CAPTURE);
390 		if (ret)
391 			goto out;
392 	}
393  out:
394 	return ret;
395 }
396 
atmel_pcm_free_dma_buffers(struct snd_pcm * pcm)397 static void atmel_pcm_free_dma_buffers(struct snd_pcm *pcm)
398 {
399 	struct snd_pcm_substream *substream;
400 	struct snd_dma_buffer *buf;
401 	int stream;
402 
403 	for (stream = 0; stream < 2; stream++) {
404 		substream = pcm->streams[stream].substream;
405 		if (!substream)
406 			continue;
407 
408 		buf = &substream->dma_buffer;
409 		if (!buf->area)
410 			continue;
411 		dma_free_coherent(pcm->card->dev, buf->bytes,
412 				  buf->area, buf->addr);
413 		buf->area = NULL;
414 	}
415 }
416 
417 #ifdef CONFIG_PM
atmel_pcm_suspend(struct snd_soc_dai * dai)418 static int atmel_pcm_suspend(struct snd_soc_dai *dai)
419 {
420 	struct snd_pcm_runtime *runtime = dai->runtime;
421 	struct atmel_runtime_data *prtd;
422 	struct atmel_pcm_dma_params *params;
423 
424 	if (!runtime)
425 		return 0;
426 
427 	prtd = runtime->private_data;
428 	params = prtd->params;
429 
430 	/* disable the PDC and save the PDC registers */
431 
432 	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_disable);
433 
434 	prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr);
435 	prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr);
436 	prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr);
437 	prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr);
438 
439 	return 0;
440 }
441 
atmel_pcm_resume(struct snd_soc_dai * dai)442 static int atmel_pcm_resume(struct snd_soc_dai *dai)
443 {
444 	struct snd_pcm_runtime *runtime = dai->runtime;
445 	struct atmel_runtime_data *prtd;
446 	struct atmel_pcm_dma_params *params;
447 
448 	if (!runtime)
449 		return 0;
450 
451 	prtd = runtime->private_data;
452 	params = prtd->params;
453 
454 	/* restore the PDC registers and enable the PDC */
455 	ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save);
456 	ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save);
457 	ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save);
458 	ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save);
459 
460 	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_enable);
461 	return 0;
462 }
463 #else
464 #define atmel_pcm_suspend	NULL
465 #define atmel_pcm_resume	NULL
466 #endif
467 
468 static struct snd_soc_platform_driver atmel_soc_platform = {
469 	.ops		= &atmel_pcm_ops,
470 	.pcm_new	= atmel_pcm_new,
471 	.pcm_free	= atmel_pcm_free_dma_buffers,
472 	.suspend	= atmel_pcm_suspend,
473 	.resume		= atmel_pcm_resume,
474 };
475 
atmel_soc_platform_probe(struct platform_device * pdev)476 static int __devinit atmel_soc_platform_probe(struct platform_device *pdev)
477 {
478 	return snd_soc_register_platform(&pdev->dev, &atmel_soc_platform);
479 }
480 
atmel_soc_platform_remove(struct platform_device * pdev)481 static int __devexit atmel_soc_platform_remove(struct platform_device *pdev)
482 {
483 	snd_soc_unregister_platform(&pdev->dev);
484 	return 0;
485 }
486 
487 static struct platform_driver atmel_pcm_driver = {
488 	.driver = {
489 			.name = "atmel-pcm-audio",
490 			.owner = THIS_MODULE,
491 	},
492 
493 	.probe = atmel_soc_platform_probe,
494 	.remove = __devexit_p(atmel_soc_platform_remove),
495 };
496 
497 module_platform_driver(atmel_pcm_driver);
498 
499 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
500 MODULE_DESCRIPTION("Atmel PCM module");
501 MODULE_LICENSE("GPL");
502