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 
atmel_pcm_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)37 static 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  */
60 static 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 \*--------------------------------------------------------------------------*/
76 struct 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 \*--------------------------------------------------------------------------*/
atmel_pcm_dma_irq(u32 ssc_sr,struct snd_pcm_substream * substream)88 static 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 \*--------------------------------------------------------------------------*/
atmel_pcm_hw_params(struct snd_soc_component * component,struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)137 static 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 = asoc_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(asoc_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 
atmel_pcm_hw_free(struct snd_soc_component * component,struct snd_pcm_substream * substream)164 static 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 
atmel_pcm_prepare(struct snd_soc_component * component,struct snd_pcm_substream * substream)179 static 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 
atmel_pcm_trigger(struct snd_soc_component * component,struct snd_pcm_substream * substream,int cmd)192 static 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 
atmel_pcm_pointer(struct snd_soc_component * component,struct snd_pcm_substream * substream)258 static 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 
atmel_pcm_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)276 static 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 
atmel_pcm_close(struct snd_soc_component * component,struct snd_pcm_substream * substream)302 static 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 
311 static 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 
atmel_pcm_pdc_platform_register(struct device * dev)322 int atmel_pcm_pdc_platform_register(struct device *dev)
323 {
324 	return devm_snd_soc_register_component(dev, &atmel_soc_platform,
325 					       NULL, 0);
326 }
327 EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
328 
329 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
330 MODULE_DESCRIPTION("Atmel PCM module");
331 MODULE_LICENSE("GPL");
332