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_preallocate_dma_buffer(struct snd_pcm * pcm,int stream)37 static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
38 int stream)
39 {
40 struct snd_pcm_substream *substream = pcm->streams[stream].substream;
41 struct snd_dma_buffer *buf = &substream->dma_buffer;
42 size_t size = ATMEL_SSC_DMABUF_SIZE;
43
44 buf->dev.type = SNDRV_DMA_TYPE_DEV;
45 buf->dev.dev = pcm->card->dev;
46 buf->private_data = NULL;
47 buf->area = dma_alloc_coherent(pcm->card->dev, size,
48 &buf->addr, GFP_KERNEL);
49 pr_debug("atmel-pcm: alloc dma buffer: area=%p, addr=%p, size=%zu\n",
50 (void *)buf->area, (void *)(long)buf->addr, size);
51
52 if (!buf->area)
53 return -ENOMEM;
54
55 buf->bytes = size;
56 return 0;
57 }
58
atmel_pcm_mmap(struct snd_pcm_substream * substream,struct vm_area_struct * vma)59 static int atmel_pcm_mmap(struct snd_pcm_substream *substream,
60 struct vm_area_struct *vma)
61 {
62 return remap_pfn_range(vma, vma->vm_start,
63 substream->dma_buffer.addr >> PAGE_SHIFT,
64 vma->vm_end - vma->vm_start, vma->vm_page_prot);
65 }
66
atmel_pcm_new(struct snd_soc_pcm_runtime * rtd)67 static int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
68 {
69 struct snd_card *card = rtd->card->snd_card;
70 struct snd_pcm *pcm = rtd->pcm;
71 int ret;
72
73 ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
74 if (ret)
75 return ret;
76
77 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
78 pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
79 ret = atmel_pcm_preallocate_dma_buffer(pcm,
80 SNDRV_PCM_STREAM_PLAYBACK);
81 if (ret)
82 goto out;
83 }
84
85 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
86 pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
87 ret = atmel_pcm_preallocate_dma_buffer(pcm,
88 SNDRV_PCM_STREAM_CAPTURE);
89 if (ret)
90 goto out;
91 }
92 out:
93 return ret;
94 }
95
atmel_pcm_free(struct snd_pcm * pcm)96 static void atmel_pcm_free(struct snd_pcm *pcm)
97 {
98 struct snd_pcm_substream *substream;
99 struct snd_dma_buffer *buf;
100 int stream;
101
102 for (stream = 0; stream < 2; stream++) {
103 substream = pcm->streams[stream].substream;
104 if (!substream)
105 continue;
106
107 buf = &substream->dma_buffer;
108 if (!buf->area)
109 continue;
110 dma_free_coherent(pcm->card->dev, buf->bytes,
111 buf->area, buf->addr);
112 buf->area = NULL;
113 }
114 }
115
116 /*--------------------------------------------------------------------------*\
117 * Hardware definition
118 \*--------------------------------------------------------------------------*/
119 /* TODO: These values were taken from the AT91 platform driver, check
120 * them against real values for AT32
121 */
122 static const struct snd_pcm_hardware atmel_pcm_hardware = {
123 .info = SNDRV_PCM_INFO_MMAP |
124 SNDRV_PCM_INFO_MMAP_VALID |
125 SNDRV_PCM_INFO_INTERLEAVED |
126 SNDRV_PCM_INFO_PAUSE,
127 .period_bytes_min = 32,
128 .period_bytes_max = 8192,
129 .periods_min = 2,
130 .periods_max = 1024,
131 .buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE,
132 };
133
134
135 /*--------------------------------------------------------------------------*\
136 * Data types
137 \*--------------------------------------------------------------------------*/
138 struct atmel_runtime_data {
139 struct atmel_pcm_dma_params *params;
140 dma_addr_t dma_buffer; /* physical address of dma buffer */
141 dma_addr_t dma_buffer_end; /* first address beyond DMA buffer */
142 size_t period_size;
143
144 dma_addr_t period_ptr; /* physical address of next period */
145 };
146
147 /*--------------------------------------------------------------------------*\
148 * ISR
149 \*--------------------------------------------------------------------------*/
atmel_pcm_dma_irq(u32 ssc_sr,struct snd_pcm_substream * substream)150 static void atmel_pcm_dma_irq(u32 ssc_sr,
151 struct snd_pcm_substream *substream)
152 {
153 struct atmel_runtime_data *prtd = substream->runtime->private_data;
154 struct atmel_pcm_dma_params *params = prtd->params;
155 static int count;
156
157 count++;
158
159 if (ssc_sr & params->mask->ssc_endbuf) {
160 pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
161 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
162 ? "underrun" : "overrun",
163 params->name, ssc_sr, count);
164
165 /* re-start the PDC */
166 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
167 params->mask->pdc_disable);
168 prtd->period_ptr += prtd->period_size;
169 if (prtd->period_ptr >= prtd->dma_buffer_end)
170 prtd->period_ptr = prtd->dma_buffer;
171
172 ssc_writex(params->ssc->regs, params->pdc->xpr,
173 prtd->period_ptr);
174 ssc_writex(params->ssc->regs, params->pdc->xcr,
175 prtd->period_size / params->pdc_xfer_size);
176 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
177 params->mask->pdc_enable);
178 }
179
180 if (ssc_sr & params->mask->ssc_endx) {
181 /* Load the PDC next pointer and counter registers */
182 prtd->period_ptr += prtd->period_size;
183 if (prtd->period_ptr >= prtd->dma_buffer_end)
184 prtd->period_ptr = prtd->dma_buffer;
185
186 ssc_writex(params->ssc->regs, params->pdc->xnpr,
187 prtd->period_ptr);
188 ssc_writex(params->ssc->regs, params->pdc->xncr,
189 prtd->period_size / params->pdc_xfer_size);
190 }
191
192 snd_pcm_period_elapsed(substream);
193 }
194
195
196 /*--------------------------------------------------------------------------*\
197 * PCM operations
198 \*--------------------------------------------------------------------------*/
atmel_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)199 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
200 struct snd_pcm_hw_params *params)
201 {
202 struct snd_pcm_runtime *runtime = substream->runtime;
203 struct atmel_runtime_data *prtd = runtime->private_data;
204 struct snd_soc_pcm_runtime *rtd = substream->private_data;
205
206 /* this may get called several times by oss emulation
207 * with different params */
208
209 snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
210 runtime->dma_bytes = params_buffer_bytes(params);
211
212 prtd->params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
213 prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
214
215 prtd->dma_buffer = runtime->dma_addr;
216 prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
217 prtd->period_size = params_period_bytes(params);
218
219 pr_debug("atmel-pcm: "
220 "hw_params: DMA for %s initialized "
221 "(dma_bytes=%zu, period_size=%zu)\n",
222 prtd->params->name,
223 runtime->dma_bytes,
224 prtd->period_size);
225 return 0;
226 }
227
atmel_pcm_hw_free(struct snd_pcm_substream * substream)228 static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
229 {
230 struct atmel_runtime_data *prtd = substream->runtime->private_data;
231 struct atmel_pcm_dma_params *params = prtd->params;
232
233 if (params != NULL) {
234 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
235 params->mask->pdc_disable);
236 prtd->params->dma_intr_handler = NULL;
237 }
238
239 return 0;
240 }
241
atmel_pcm_prepare(struct snd_pcm_substream * substream)242 static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
243 {
244 struct atmel_runtime_data *prtd = substream->runtime->private_data;
245 struct atmel_pcm_dma_params *params = prtd->params;
246
247 ssc_writex(params->ssc->regs, SSC_IDR,
248 params->mask->ssc_endx | params->mask->ssc_endbuf);
249 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
250 params->mask->pdc_disable);
251 return 0;
252 }
253
atmel_pcm_trigger(struct snd_pcm_substream * substream,int cmd)254 static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
255 int cmd)
256 {
257 struct snd_pcm_runtime *rtd = substream->runtime;
258 struct atmel_runtime_data *prtd = rtd->private_data;
259 struct atmel_pcm_dma_params *params = prtd->params;
260 int ret = 0;
261
262 pr_debug("atmel-pcm:buffer_size = %ld,"
263 "dma_area = %p, dma_bytes = %zu\n",
264 rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
265
266 switch (cmd) {
267 case SNDRV_PCM_TRIGGER_START:
268 prtd->period_ptr = prtd->dma_buffer;
269
270 ssc_writex(params->ssc->regs, params->pdc->xpr,
271 prtd->period_ptr);
272 ssc_writex(params->ssc->regs, params->pdc->xcr,
273 prtd->period_size / params->pdc_xfer_size);
274
275 prtd->period_ptr += prtd->period_size;
276 ssc_writex(params->ssc->regs, params->pdc->xnpr,
277 prtd->period_ptr);
278 ssc_writex(params->ssc->regs, params->pdc->xncr,
279 prtd->period_size / params->pdc_xfer_size);
280
281 pr_debug("atmel-pcm: trigger: "
282 "period_ptr=%lx, xpr=%u, "
283 "xcr=%u, xnpr=%u, xncr=%u\n",
284 (unsigned long)prtd->period_ptr,
285 ssc_readx(params->ssc->regs, params->pdc->xpr),
286 ssc_readx(params->ssc->regs, params->pdc->xcr),
287 ssc_readx(params->ssc->regs, params->pdc->xnpr),
288 ssc_readx(params->ssc->regs, params->pdc->xncr));
289
290 ssc_writex(params->ssc->regs, SSC_IER,
291 params->mask->ssc_endx | params->mask->ssc_endbuf);
292 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
293 params->mask->pdc_enable);
294
295 pr_debug("sr=%u imr=%u\n",
296 ssc_readx(params->ssc->regs, SSC_SR),
297 ssc_readx(params->ssc->regs, SSC_IER));
298 break; /* SNDRV_PCM_TRIGGER_START */
299
300 case SNDRV_PCM_TRIGGER_STOP:
301 case SNDRV_PCM_TRIGGER_SUSPEND:
302 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
303 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
304 params->mask->pdc_disable);
305 break;
306
307 case SNDRV_PCM_TRIGGER_RESUME:
308 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
309 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
310 params->mask->pdc_enable);
311 break;
312
313 default:
314 ret = -EINVAL;
315 }
316
317 return ret;
318 }
319
atmel_pcm_pointer(struct snd_pcm_substream * substream)320 static snd_pcm_uframes_t atmel_pcm_pointer(
321 struct snd_pcm_substream *substream)
322 {
323 struct snd_pcm_runtime *runtime = substream->runtime;
324 struct atmel_runtime_data *prtd = runtime->private_data;
325 struct atmel_pcm_dma_params *params = prtd->params;
326 dma_addr_t ptr;
327 snd_pcm_uframes_t x;
328
329 ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
330 x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
331
332 if (x == runtime->buffer_size)
333 x = 0;
334
335 return x;
336 }
337
atmel_pcm_open(struct snd_pcm_substream * substream)338 static int atmel_pcm_open(struct snd_pcm_substream *substream)
339 {
340 struct snd_pcm_runtime *runtime = substream->runtime;
341 struct atmel_runtime_data *prtd;
342 int ret = 0;
343
344 snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
345
346 /* ensure that buffer size is a multiple of period size */
347 ret = snd_pcm_hw_constraint_integer(runtime,
348 SNDRV_PCM_HW_PARAM_PERIODS);
349 if (ret < 0)
350 goto out;
351
352 prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
353 if (prtd == NULL) {
354 ret = -ENOMEM;
355 goto out;
356 }
357 runtime->private_data = prtd;
358
359 out:
360 return ret;
361 }
362
atmel_pcm_close(struct snd_pcm_substream * substream)363 static int atmel_pcm_close(struct snd_pcm_substream *substream)
364 {
365 struct atmel_runtime_data *prtd = substream->runtime->private_data;
366
367 kfree(prtd);
368 return 0;
369 }
370
371 static const struct snd_pcm_ops atmel_pcm_ops = {
372 .open = atmel_pcm_open,
373 .close = atmel_pcm_close,
374 .ioctl = snd_pcm_lib_ioctl,
375 .hw_params = atmel_pcm_hw_params,
376 .hw_free = atmel_pcm_hw_free,
377 .prepare = atmel_pcm_prepare,
378 .trigger = atmel_pcm_trigger,
379 .pointer = atmel_pcm_pointer,
380 .mmap = atmel_pcm_mmap,
381 };
382
383 static struct snd_soc_component_driver atmel_soc_platform = {
384 .ops = &atmel_pcm_ops,
385 .pcm_new = atmel_pcm_new,
386 .pcm_free = atmel_pcm_free,
387 };
388
atmel_pcm_pdc_platform_register(struct device * dev)389 int atmel_pcm_pdc_platform_register(struct device *dev)
390 {
391 return devm_snd_soc_register_component(dev, &atmel_soc_platform,
392 NULL, 0);
393 }
394 EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
395
396 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
397 MODULE_DESCRIPTION("Atmel PCM module");
398 MODULE_LICENSE("GPL");
399