xref: /openbmc/linux/sound/soc/atmel/atmel-pcm-pdc.c (revision 8a10bc9d)
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 	.period_bytes_min	= 32,
62 	.period_bytes_max	= 8192,
63 	.periods_min		= 2,
64 	.periods_max		= 1024,
65 	.buffer_bytes_max	= ATMEL_SSC_DMABUF_SIZE,
66 };
67 
68 
69 /*--------------------------------------------------------------------------*\
70  * Data types
71 \*--------------------------------------------------------------------------*/
72 struct atmel_runtime_data {
73 	struct atmel_pcm_dma_params *params;
74 	dma_addr_t dma_buffer;		/* physical address of dma buffer */
75 	dma_addr_t dma_buffer_end;	/* first address beyond DMA buffer */
76 	size_t period_size;
77 
78 	dma_addr_t period_ptr;		/* physical address of next period */
79 
80 	/* PDC register save */
81 	u32 pdc_xpr_save;
82 	u32 pdc_xcr_save;
83 	u32 pdc_xnpr_save;
84 	u32 pdc_xncr_save;
85 };
86 
87 /*--------------------------------------------------------------------------*\
88  * ISR
89 \*--------------------------------------------------------------------------*/
90 static void atmel_pcm_dma_irq(u32 ssc_sr,
91 	struct snd_pcm_substream *substream)
92 {
93 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
94 	struct atmel_pcm_dma_params *params = prtd->params;
95 	static int count;
96 
97 	count++;
98 
99 	if (ssc_sr & params->mask->ssc_endbuf) {
100 		pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
101 				substream->stream == SNDRV_PCM_STREAM_PLAYBACK
102 				? "underrun" : "overrun",
103 				params->name, ssc_sr, count);
104 
105 		/* re-start the PDC */
106 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
107 			   params->mask->pdc_disable);
108 		prtd->period_ptr += prtd->period_size;
109 		if (prtd->period_ptr >= prtd->dma_buffer_end)
110 			prtd->period_ptr = prtd->dma_buffer;
111 
112 		ssc_writex(params->ssc->regs, params->pdc->xpr,
113 			   prtd->period_ptr);
114 		ssc_writex(params->ssc->regs, params->pdc->xcr,
115 			   prtd->period_size / params->pdc_xfer_size);
116 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
117 			   params->mask->pdc_enable);
118 	}
119 
120 	if (ssc_sr & params->mask->ssc_endx) {
121 		/* Load the PDC next pointer and counter registers */
122 		prtd->period_ptr += prtd->period_size;
123 		if (prtd->period_ptr >= prtd->dma_buffer_end)
124 			prtd->period_ptr = prtd->dma_buffer;
125 
126 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
127 			   prtd->period_ptr);
128 		ssc_writex(params->ssc->regs, params->pdc->xncr,
129 			   prtd->period_size / params->pdc_xfer_size);
130 	}
131 
132 	snd_pcm_period_elapsed(substream);
133 }
134 
135 
136 /*--------------------------------------------------------------------------*\
137  * PCM operations
138 \*--------------------------------------------------------------------------*/
139 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
140 	struct snd_pcm_hw_params *params)
141 {
142 	struct snd_pcm_runtime *runtime = substream->runtime;
143 	struct atmel_runtime_data *prtd = runtime->private_data;
144 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
145 
146 	/* this may get called several times by oss emulation
147 	 * with different params */
148 
149 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
150 	runtime->dma_bytes = params_buffer_bytes(params);
151 
152 	prtd->params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
153 	prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
154 
155 	prtd->dma_buffer = runtime->dma_addr;
156 	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
157 	prtd->period_size = params_period_bytes(params);
158 
159 	pr_debug("atmel-pcm: "
160 		"hw_params: DMA for %s initialized "
161 		"(dma_bytes=%zu, period_size=%zu)\n",
162 		prtd->params->name,
163 		runtime->dma_bytes,
164 		prtd->period_size);
165 	return 0;
166 }
167 
168 static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
169 {
170 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
171 	struct atmel_pcm_dma_params *params = prtd->params;
172 
173 	if (params != NULL) {
174 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
175 			   params->mask->pdc_disable);
176 		prtd->params->dma_intr_handler = NULL;
177 	}
178 
179 	return 0;
180 }
181 
182 static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
183 {
184 	struct atmel_runtime_data *prtd = substream->runtime->private_data;
185 	struct atmel_pcm_dma_params *params = prtd->params;
186 
187 	ssc_writex(params->ssc->regs, SSC_IDR,
188 		   params->mask->ssc_endx | params->mask->ssc_endbuf);
189 	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
190 		   params->mask->pdc_disable);
191 	return 0;
192 }
193 
194 static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
195 	int cmd)
196 {
197 	struct snd_pcm_runtime *rtd = substream->runtime;
198 	struct atmel_runtime_data *prtd = rtd->private_data;
199 	struct atmel_pcm_dma_params *params = prtd->params;
200 	int ret = 0;
201 
202 	pr_debug("atmel-pcm:buffer_size = %ld,"
203 		"dma_area = %p, dma_bytes = %zu\n",
204 		rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
205 
206 	switch (cmd) {
207 	case SNDRV_PCM_TRIGGER_START:
208 		prtd->period_ptr = prtd->dma_buffer;
209 
210 		ssc_writex(params->ssc->regs, params->pdc->xpr,
211 			   prtd->period_ptr);
212 		ssc_writex(params->ssc->regs, params->pdc->xcr,
213 			   prtd->period_size / params->pdc_xfer_size);
214 
215 		prtd->period_ptr += prtd->period_size;
216 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
217 			   prtd->period_ptr);
218 		ssc_writex(params->ssc->regs, params->pdc->xncr,
219 			   prtd->period_size / params->pdc_xfer_size);
220 
221 		pr_debug("atmel-pcm: trigger: "
222 			"period_ptr=%lx, xpr=%u, "
223 			"xcr=%u, xnpr=%u, xncr=%u\n",
224 			(unsigned long)prtd->period_ptr,
225 			ssc_readx(params->ssc->regs, params->pdc->xpr),
226 			ssc_readx(params->ssc->regs, params->pdc->xcr),
227 			ssc_readx(params->ssc->regs, params->pdc->xnpr),
228 			ssc_readx(params->ssc->regs, params->pdc->xncr));
229 
230 		ssc_writex(params->ssc->regs, SSC_IER,
231 			   params->mask->ssc_endx | params->mask->ssc_endbuf);
232 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
233 			   params->mask->pdc_enable);
234 
235 		pr_debug("sr=%u imr=%u\n",
236 			ssc_readx(params->ssc->regs, SSC_SR),
237 			ssc_readx(params->ssc->regs, SSC_IER));
238 		break;		/* SNDRV_PCM_TRIGGER_START */
239 
240 	case SNDRV_PCM_TRIGGER_STOP:
241 	case SNDRV_PCM_TRIGGER_SUSPEND:
242 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
243 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
244 			   params->mask->pdc_disable);
245 		break;
246 
247 	case SNDRV_PCM_TRIGGER_RESUME:
248 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
249 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
250 			   params->mask->pdc_enable);
251 		break;
252 
253 	default:
254 		ret = -EINVAL;
255 	}
256 
257 	return ret;
258 }
259 
260 static snd_pcm_uframes_t atmel_pcm_pointer(
261 	struct snd_pcm_substream *substream)
262 {
263 	struct snd_pcm_runtime *runtime = substream->runtime;
264 	struct atmel_runtime_data *prtd = runtime->private_data;
265 	struct atmel_pcm_dma_params *params = prtd->params;
266 	dma_addr_t ptr;
267 	snd_pcm_uframes_t x;
268 
269 	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
270 	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
271 
272 	if (x == runtime->buffer_size)
273 		x = 0;
274 
275 	return x;
276 }
277 
278 static int atmel_pcm_open(struct snd_pcm_substream *substream)
279 {
280 	struct snd_pcm_runtime *runtime = substream->runtime;
281 	struct atmel_runtime_data *prtd;
282 	int ret = 0;
283 
284 	snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
285 
286 	/* ensure that buffer size is a multiple of period size */
287 	ret = snd_pcm_hw_constraint_integer(runtime,
288 						SNDRV_PCM_HW_PARAM_PERIODS);
289 	if (ret < 0)
290 		goto out;
291 
292 	prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
293 	if (prtd == NULL) {
294 		ret = -ENOMEM;
295 		goto out;
296 	}
297 	runtime->private_data = prtd;
298 
299  out:
300 	return ret;
301 }
302 
303 static int atmel_pcm_close(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 
311 static struct snd_pcm_ops atmel_pcm_ops = {
312 	.open		= atmel_pcm_open,
313 	.close		= atmel_pcm_close,
314 	.ioctl		= snd_pcm_lib_ioctl,
315 	.hw_params	= atmel_pcm_hw_params,
316 	.hw_free	= atmel_pcm_hw_free,
317 	.prepare	= atmel_pcm_prepare,
318 	.trigger	= atmel_pcm_trigger,
319 	.pointer	= atmel_pcm_pointer,
320 	.mmap		= atmel_pcm_mmap,
321 };
322 
323 
324 /*--------------------------------------------------------------------------*\
325  * ASoC platform driver
326 \*--------------------------------------------------------------------------*/
327 #ifdef CONFIG_PM
328 static int atmel_pcm_suspend(struct snd_soc_dai *dai)
329 {
330 	struct snd_pcm_runtime *runtime = dai->runtime;
331 	struct atmel_runtime_data *prtd;
332 	struct atmel_pcm_dma_params *params;
333 
334 	if (!runtime)
335 		return 0;
336 
337 	prtd = runtime->private_data;
338 	params = prtd->params;
339 
340 	/* disable the PDC and save the PDC registers */
341 
342 	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_disable);
343 
344 	prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr);
345 	prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr);
346 	prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr);
347 	prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr);
348 
349 	return 0;
350 }
351 
352 static int atmel_pcm_resume(struct snd_soc_dai *dai)
353 {
354 	struct snd_pcm_runtime *runtime = dai->runtime;
355 	struct atmel_runtime_data *prtd;
356 	struct atmel_pcm_dma_params *params;
357 
358 	if (!runtime)
359 		return 0;
360 
361 	prtd = runtime->private_data;
362 	params = prtd->params;
363 
364 	/* restore the PDC registers and enable the PDC */
365 	ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save);
366 	ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save);
367 	ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save);
368 	ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save);
369 
370 	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_enable);
371 	return 0;
372 }
373 #else
374 #define atmel_pcm_suspend	NULL
375 #define atmel_pcm_resume	NULL
376 #endif
377 
378 static struct snd_soc_platform_driver atmel_soc_platform = {
379 	.ops		= &atmel_pcm_ops,
380 	.pcm_new	= atmel_pcm_new,
381 	.pcm_free	= atmel_pcm_free,
382 	.suspend	= atmel_pcm_suspend,
383 	.resume		= atmel_pcm_resume,
384 };
385 
386 int atmel_pcm_pdc_platform_register(struct device *dev)
387 {
388 	return snd_soc_register_platform(dev, &atmel_soc_platform);
389 }
390 EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
391 
392 void atmel_pcm_pdc_platform_unregister(struct device *dev)
393 {
394 	snd_soc_unregister_platform(dev);
395 }
396 EXPORT_SYMBOL(atmel_pcm_pdc_platform_unregister);
397 
398 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
399 MODULE_DESCRIPTION("Atmel PCM module");
400 MODULE_LICENSE("GPL");
401