atmel-pcm-pdc.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * atmel-pcm.c  --  ALSA PCM interface for the Atmel atmel SoC.
  4 *
  5 *  Copyright (C) 2005 SAN People
  6 *  Copyright (C) 2008 Atmel
  7 *
  8 * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
  9 *
 10 * Based on at91-pcm. by:
 11 * Frank Mandarino <fmandarino@endrelia.com>
 12 * Copyright 2006 Endrelia Technologies Inc.
 13 *
 14 * Based on pxa2xx-pcm.c by:
 15 *
 16 * Author:	Nicolas Pitre
 17 * Created:	Nov 30, 2004
 18 * Copyright:	(C) 2004 MontaVista Software, Inc.
 19 */
 20
 21#include <linux/module.h>
 22#include <linux/init.h>
 23#include <linux/platform_device.h>
 24#include <linux/slab.h>
 25#include <linux/dma-mapping.h>
 26#include <linux/atmel_pdc.h>
 27#include <linux/atmel-ssc.h>
 28
 29#include <sound/core.h>
 30#include <sound/pcm.h>
 31#include <sound/pcm_params.h>
 32#include <sound/soc.h>
 33
 34#include "atmel-pcm.h"
 35
 36
 37static int atmel_pcm_new(struct snd_soc_component *component,
 38			 struct snd_soc_pcm_runtime *rtd)
 39{
 40	struct snd_card *card = rtd->card->snd_card;
 41	int ret;
 42
 43	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 44	if (ret)
 45		return ret;
 46
 47	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
 48				       card->dev, ATMEL_SSC_DMABUF_SIZE,
 49				       ATMEL_SSC_DMABUF_SIZE);
 50
 51	return 0;
 52}
 53
 54/*--------------------------------------------------------------------------*\
 55 * Hardware definition
 56\*--------------------------------------------------------------------------*/
 57/* TODO: These values were taken from the AT91 platform driver, check
 58 *	 them against real values for AT32
 59 */
 60static const struct snd_pcm_hardware atmel_pcm_hardware = {
 61	.info			= SNDRV_PCM_INFO_MMAP |
 62				  SNDRV_PCM_INFO_MMAP_VALID |
 63				  SNDRV_PCM_INFO_INTERLEAVED |
 64				  SNDRV_PCM_INFO_PAUSE,
 65	.period_bytes_min	= 32,
 66	.period_bytes_max	= 8192,
 67	.periods_min		= 2,
 68	.periods_max		= 1024,
 69	.buffer_bytes_max	= ATMEL_SSC_DMABUF_SIZE,
 70};
 71
 72
 73/*--------------------------------------------------------------------------*\
 74 * Data types
 75\*--------------------------------------------------------------------------*/
 76struct atmel_runtime_data {
 77	struct atmel_pcm_dma_params *params;
 78	dma_addr_t dma_buffer;		/* physical address of dma buffer */
 79	dma_addr_t dma_buffer_end;	/* first address beyond DMA buffer */
 80	size_t period_size;
 81
 82	dma_addr_t period_ptr;		/* physical address of next period */
 83};
 84
 85/*--------------------------------------------------------------------------*\
 86 * ISR
 87\*--------------------------------------------------------------------------*/
 88static void atmel_pcm_dma_irq(u32 ssc_sr,
 89	struct snd_pcm_substream *substream)
 90{
 91	struct atmel_runtime_data *prtd = substream->runtime->private_data;
 92	struct atmel_pcm_dma_params *params = prtd->params;
 93	static int count;
 94
 95	count++;
 96
 97	if (ssc_sr & params->mask->ssc_endbuf) {
 98		pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
 99				substream->stream == SNDRV_PCM_STREAM_PLAYBACK
100				? "underrun" : "overrun",
101				params->name, ssc_sr, count);
102
103		/* re-start the PDC */
104		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
105			   params->mask->pdc_disable);
106		prtd->period_ptr += prtd->period_size;
107		if (prtd->period_ptr >= prtd->dma_buffer_end)
108			prtd->period_ptr = prtd->dma_buffer;
109
110		ssc_writex(params->ssc->regs, params->pdc->xpr,
111			   prtd->period_ptr);
112		ssc_writex(params->ssc->regs, params->pdc->xcr,
113			   prtd->period_size / params->pdc_xfer_size);
114		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
115			   params->mask->pdc_enable);
116	}
117
118	if (ssc_sr & params->mask->ssc_endx) {
119		/* Load the PDC next pointer and counter registers */
120		prtd->period_ptr += prtd->period_size;
121		if (prtd->period_ptr >= prtd->dma_buffer_end)
122			prtd->period_ptr = prtd->dma_buffer;
123
124		ssc_writex(params->ssc->regs, params->pdc->xnpr,
125			   prtd->period_ptr);
126		ssc_writex(params->ssc->regs, params->pdc->xncr,
127			   prtd->period_size / params->pdc_xfer_size);
128	}
129
130	snd_pcm_period_elapsed(substream);
131}
132
133
134/*--------------------------------------------------------------------------*\
135 * PCM operations
136\*--------------------------------------------------------------------------*/
137static int atmel_pcm_hw_params(struct snd_soc_component *component,
138			       struct snd_pcm_substream *substream,
139			       struct snd_pcm_hw_params *params)
140{
141	struct snd_pcm_runtime *runtime = substream->runtime;
142	struct atmel_runtime_data *prtd = runtime->private_data;
143	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
144
145	/* this may get called several times by oss emulation
146	 * with different params */
147
148	prtd->params = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
149	prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
150
151	prtd->dma_buffer = runtime->dma_addr;
152	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
153	prtd->period_size = params_period_bytes(params);
154
155	pr_debug("atmel-pcm: "
156		"hw_params: DMA for %s initialized "
157		"(dma_bytes=%zu, period_size=%zu)\n",
158		prtd->params->name,
159		runtime->dma_bytes,
160		prtd->period_size);
161	return 0;
162}
163
164static int atmel_pcm_hw_free(struct snd_soc_component *component,
165			     struct snd_pcm_substream *substream)
166{
167	struct atmel_runtime_data *prtd = substream->runtime->private_data;
168	struct atmel_pcm_dma_params *params = prtd->params;
169
170	if (params != NULL) {
171		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
172			   params->mask->pdc_disable);
173		prtd->params->dma_intr_handler = NULL;
174	}
175
176	return 0;
177}
178
179static int atmel_pcm_prepare(struct snd_soc_component *component,
180			     struct snd_pcm_substream *substream)
181{
182	struct atmel_runtime_data *prtd = substream->runtime->private_data;
183	struct atmel_pcm_dma_params *params = prtd->params;
184
185	ssc_writex(params->ssc->regs, SSC_IDR,
186		   params->mask->ssc_endx | params->mask->ssc_endbuf);
187	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
188		   params->mask->pdc_disable);
189	return 0;
190}
191
192static int atmel_pcm_trigger(struct snd_soc_component *component,
193			     struct snd_pcm_substream *substream, int cmd)
194{
195	struct snd_pcm_runtime *rtd = substream->runtime;
196	struct atmel_runtime_data *prtd = rtd->private_data;
197	struct atmel_pcm_dma_params *params = prtd->params;
198	int ret = 0;
199
200	pr_debug("atmel-pcm:buffer_size = %ld,"
201		"dma_area = %p, dma_bytes = %zu\n",
202		rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
203
204	switch (cmd) {
205	case SNDRV_PCM_TRIGGER_START:
206		prtd->period_ptr = prtd->dma_buffer;
207
208		ssc_writex(params->ssc->regs, params->pdc->xpr,
209			   prtd->period_ptr);
210		ssc_writex(params->ssc->regs, params->pdc->xcr,
211			   prtd->period_size / params->pdc_xfer_size);
212
213		prtd->period_ptr += prtd->period_size;
214		ssc_writex(params->ssc->regs, params->pdc->xnpr,
215			   prtd->period_ptr);
216		ssc_writex(params->ssc->regs, params->pdc->xncr,
217			   prtd->period_size / params->pdc_xfer_size);
218
219		pr_debug("atmel-pcm: trigger: "
220			"period_ptr=%lx, xpr=%u, "
221			"xcr=%u, xnpr=%u, xncr=%u\n",
222			(unsigned long)prtd->period_ptr,
223			ssc_readx(params->ssc->regs, params->pdc->xpr),
224			ssc_readx(params->ssc->regs, params->pdc->xcr),
225			ssc_readx(params->ssc->regs, params->pdc->xnpr),
226			ssc_readx(params->ssc->regs, params->pdc->xncr));
227
228		ssc_writex(params->ssc->regs, SSC_IER,
229			   params->mask->ssc_endx | params->mask->ssc_endbuf);
230		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
231			   params->mask->pdc_enable);
232
233		pr_debug("sr=%u imr=%u\n",
234			ssc_readx(params->ssc->regs, SSC_SR),
235			ssc_readx(params->ssc->regs, SSC_IER));
236		break;		/* SNDRV_PCM_TRIGGER_START */
237
238	case SNDRV_PCM_TRIGGER_STOP:
239	case SNDRV_PCM_TRIGGER_SUSPEND:
240	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
241		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
242			   params->mask->pdc_disable);
243		break;
244
245	case SNDRV_PCM_TRIGGER_RESUME:
246	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
247		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
248			   params->mask->pdc_enable);
249		break;
250
251	default:
252		ret = -EINVAL;
253	}
254
255	return ret;
256}
257
258static snd_pcm_uframes_t atmel_pcm_pointer(struct snd_soc_component *component,
259					   struct snd_pcm_substream *substream)
260{
261	struct snd_pcm_runtime *runtime = substream->runtime;
262	struct atmel_runtime_data *prtd = runtime->private_data;
263	struct atmel_pcm_dma_params *params = prtd->params;
264	dma_addr_t ptr;
265	snd_pcm_uframes_t x;
266
267	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
268	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
269
270	if (x == runtime->buffer_size)
271		x = 0;
272
273	return x;
274}
275
276static int atmel_pcm_open(struct snd_soc_component *component,
277			  struct snd_pcm_substream *substream)
278{
279	struct snd_pcm_runtime *runtime = substream->runtime;
280	struct atmel_runtime_data *prtd;
281	int ret = 0;
282
283	snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
284
285	/* ensure that buffer size is a multiple of period size */
286	ret = snd_pcm_hw_constraint_integer(runtime,
287						SNDRV_PCM_HW_PARAM_PERIODS);
288	if (ret < 0)
289		goto out;
290
291	prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
292	if (prtd == NULL) {
293		ret = -ENOMEM;
294		goto out;
295	}
296	runtime->private_data = prtd;
297
298 out:
299	return ret;
300}
301
302static int atmel_pcm_close(struct snd_soc_component *component,
303			   struct snd_pcm_substream *substream)
304{
305	struct atmel_runtime_data *prtd = substream->runtime->private_data;
306
307	kfree(prtd);
308	return 0;
309}
310
311static const struct snd_soc_component_driver atmel_soc_platform = {
312	.open		= atmel_pcm_open,
313	.close		= atmel_pcm_close,
314	.hw_params	= atmel_pcm_hw_params,
315	.hw_free	= atmel_pcm_hw_free,
316	.prepare	= atmel_pcm_prepare,
317	.trigger	= atmel_pcm_trigger,
318	.pointer	= atmel_pcm_pointer,
319	.pcm_construct	= atmel_pcm_new,
320};
321
322int atmel_pcm_pdc_platform_register(struct device *dev)
323{
324	return devm_snd_soc_register_component(dev, &atmel_soc_platform,
325					       NULL, 0);
326}
327EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
328
329MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
330MODULE_DESCRIPTION("Atmel PCM module");
331MODULE_LICENSE("GPL");