xref: /openbmc/linux/sound/soc/fsl/imx-pcm-fiq.c (revision 20e2fc42)
1 // SPDX-License-Identifier: GPL-2.0+
2 // imx-pcm-fiq.c  --  ALSA Soc Audio Layer
3 //
4 // Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
5 //
6 // This code is based on code copyrighted by Freescale,
7 // Liam Girdwood, Javier Martin and probably others.
8 
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 
19 #include <sound/core.h>
20 #include <sound/dmaengine_pcm.h>
21 #include <sound/initval.h>
22 #include <sound/pcm.h>
23 #include <sound/pcm_params.h>
24 #include <sound/soc.h>
25 
26 #include <asm/fiq.h>
27 
28 #include <linux/platform_data/asoc-imx-ssi.h>
29 
30 #include "imx-ssi.h"
31 #include "imx-pcm.h"
32 
33 struct imx_pcm_runtime_data {
34 	unsigned int period;
35 	int periods;
36 	unsigned long offset;
37 	struct hrtimer hrt;
38 	int poll_time_ns;
39 	struct snd_pcm_substream *substream;
40 	atomic_t playing;
41 	atomic_t capturing;
42 };
43 
44 static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
45 {
46 	struct imx_pcm_runtime_data *iprtd =
47 		container_of(hrt, struct imx_pcm_runtime_data, hrt);
48 	struct snd_pcm_substream *substream = iprtd->substream;
49 	struct pt_regs regs;
50 
51 	if (!atomic_read(&iprtd->playing) && !atomic_read(&iprtd->capturing))
52 		return HRTIMER_NORESTART;
53 
54 	get_fiq_regs(&regs);
55 
56 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
57 		iprtd->offset = regs.ARM_r8 & 0xffff;
58 	else
59 		iprtd->offset = regs.ARM_r9 & 0xffff;
60 
61 	snd_pcm_period_elapsed(substream);
62 
63 	hrtimer_forward_now(hrt, ns_to_ktime(iprtd->poll_time_ns));
64 
65 	return HRTIMER_RESTART;
66 }
67 
68 static struct fiq_handler fh = {
69 	.name		= DRV_NAME,
70 };
71 
72 static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
73 				struct snd_pcm_hw_params *params)
74 {
75 	struct snd_pcm_runtime *runtime = substream->runtime;
76 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
77 
78 	iprtd->periods = params_periods(params);
79 	iprtd->period = params_period_bytes(params);
80 	iprtd->offset = 0;
81 	iprtd->poll_time_ns = 1000000000 / params_rate(params) *
82 				params_period_size(params);
83 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
84 
85 	return 0;
86 }
87 
88 static int snd_imx_pcm_prepare(struct snd_pcm_substream *substream)
89 {
90 	struct snd_pcm_runtime *runtime = substream->runtime;
91 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
92 	struct pt_regs regs;
93 
94 	get_fiq_regs(&regs);
95 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
96 		regs.ARM_r8 = (iprtd->period * iprtd->periods - 1) << 16;
97 	else
98 		regs.ARM_r9 = (iprtd->period * iprtd->periods - 1) << 16;
99 
100 	set_fiq_regs(&regs);
101 
102 	return 0;
103 }
104 
105 static int imx_pcm_fiq;
106 
107 static int snd_imx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
108 {
109 	struct snd_pcm_runtime *runtime = substream->runtime;
110 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
111 
112 	switch (cmd) {
113 	case SNDRV_PCM_TRIGGER_START:
114 	case SNDRV_PCM_TRIGGER_RESUME:
115 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
116 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
117 			atomic_set(&iprtd->playing, 1);
118 		else
119 			atomic_set(&iprtd->capturing, 1);
120 		hrtimer_start(&iprtd->hrt, ns_to_ktime(iprtd->poll_time_ns),
121 		      HRTIMER_MODE_REL);
122 		enable_fiq(imx_pcm_fiq);
123 		break;
124 
125 	case SNDRV_PCM_TRIGGER_STOP:
126 	case SNDRV_PCM_TRIGGER_SUSPEND:
127 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
128 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
129 			atomic_set(&iprtd->playing, 0);
130 		else
131 			atomic_set(&iprtd->capturing, 0);
132 		if (!atomic_read(&iprtd->playing) &&
133 				!atomic_read(&iprtd->capturing))
134 			disable_fiq(imx_pcm_fiq);
135 		break;
136 
137 	default:
138 		return -EINVAL;
139 	}
140 
141 	return 0;
142 }
143 
144 static snd_pcm_uframes_t snd_imx_pcm_pointer(struct snd_pcm_substream *substream)
145 {
146 	struct snd_pcm_runtime *runtime = substream->runtime;
147 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
148 
149 	return bytes_to_frames(substream->runtime, iprtd->offset);
150 }
151 
152 static const struct snd_pcm_hardware snd_imx_hardware = {
153 	.info = SNDRV_PCM_INFO_INTERLEAVED |
154 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
155 		SNDRV_PCM_INFO_MMAP |
156 		SNDRV_PCM_INFO_MMAP_VALID |
157 		SNDRV_PCM_INFO_PAUSE |
158 		SNDRV_PCM_INFO_RESUME,
159 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
160 	.buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
161 	.period_bytes_min = 128,
162 	.period_bytes_max = 16 * 1024,
163 	.periods_min = 4,
164 	.periods_max = 255,
165 	.fifo_size = 0,
166 };
167 
168 static int snd_imx_open(struct snd_pcm_substream *substream)
169 {
170 	struct snd_pcm_runtime *runtime = substream->runtime;
171 	struct imx_pcm_runtime_data *iprtd;
172 	int ret;
173 
174 	iprtd = kzalloc(sizeof(*iprtd), GFP_KERNEL);
175 	if (iprtd == NULL)
176 		return -ENOMEM;
177 	runtime->private_data = iprtd;
178 
179 	iprtd->substream = substream;
180 
181 	atomic_set(&iprtd->playing, 0);
182 	atomic_set(&iprtd->capturing, 0);
183 	hrtimer_init(&iprtd->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
184 	iprtd->hrt.function = snd_hrtimer_callback;
185 
186 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
187 			SNDRV_PCM_HW_PARAM_PERIODS);
188 	if (ret < 0) {
189 		kfree(iprtd);
190 		return ret;
191 	}
192 
193 	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
194 	return 0;
195 }
196 
197 static int snd_imx_close(struct snd_pcm_substream *substream)
198 {
199 	struct snd_pcm_runtime *runtime = substream->runtime;
200 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
201 
202 	hrtimer_cancel(&iprtd->hrt);
203 
204 	kfree(iprtd);
205 
206 	return 0;
207 }
208 
209 static int snd_imx_pcm_mmap(struct snd_pcm_substream *substream,
210 		struct vm_area_struct *vma)
211 {
212 	struct snd_pcm_runtime *runtime = substream->runtime;
213 	int ret;
214 
215 	ret = dma_mmap_wc(substream->pcm->card->dev, vma, runtime->dma_area,
216 			  runtime->dma_addr, runtime->dma_bytes);
217 
218 	pr_debug("%s: ret: %d %p %pad 0x%08zx\n", __func__, ret,
219 			runtime->dma_area,
220 			&runtime->dma_addr,
221 			runtime->dma_bytes);
222 	return ret;
223 }
224 
225 static const struct snd_pcm_ops imx_pcm_ops = {
226 	.open		= snd_imx_open,
227 	.close		= snd_imx_close,
228 	.ioctl		= snd_pcm_lib_ioctl,
229 	.hw_params	= snd_imx_pcm_hw_params,
230 	.prepare	= snd_imx_pcm_prepare,
231 	.trigger	= snd_imx_pcm_trigger,
232 	.pointer	= snd_imx_pcm_pointer,
233 	.mmap		= snd_imx_pcm_mmap,
234 };
235 
236 static int imx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
237 {
238 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
239 	struct snd_dma_buffer *buf = &substream->dma_buffer;
240 	size_t size = IMX_SSI_DMABUF_SIZE;
241 
242 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
243 	buf->dev.dev = pcm->card->dev;
244 	buf->private_data = NULL;
245 	buf->area = dma_alloc_wc(pcm->card->dev, size, &buf->addr, GFP_KERNEL);
246 	if (!buf->area)
247 		return -ENOMEM;
248 	buf->bytes = size;
249 
250 	return 0;
251 }
252 
253 static int imx_pcm_new(struct snd_soc_pcm_runtime *rtd)
254 {
255 	struct snd_card *card = rtd->card->snd_card;
256 	struct snd_pcm *pcm = rtd->pcm;
257 	int ret;
258 
259 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
260 	if (ret)
261 		return ret;
262 
263 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
264 		ret = imx_pcm_preallocate_dma_buffer(pcm,
265 			SNDRV_PCM_STREAM_PLAYBACK);
266 		if (ret)
267 			return ret;
268 	}
269 
270 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
271 		ret = imx_pcm_preallocate_dma_buffer(pcm,
272 			SNDRV_PCM_STREAM_CAPTURE);
273 		if (ret)
274 			return ret;
275 	}
276 
277 	return 0;
278 }
279 
280 static int ssi_irq;
281 
282 static int imx_pcm_fiq_new(struct snd_soc_pcm_runtime *rtd)
283 {
284 	struct snd_pcm *pcm = rtd->pcm;
285 	struct snd_pcm_substream *substream;
286 	int ret;
287 
288 	ret = imx_pcm_new(rtd);
289 	if (ret)
290 		return ret;
291 
292 	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
293 	if (substream) {
294 		struct snd_dma_buffer *buf = &substream->dma_buffer;
295 
296 		imx_ssi_fiq_tx_buffer = (unsigned long)buf->area;
297 	}
298 
299 	substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
300 	if (substream) {
301 		struct snd_dma_buffer *buf = &substream->dma_buffer;
302 
303 		imx_ssi_fiq_rx_buffer = (unsigned long)buf->area;
304 	}
305 
306 	set_fiq_handler(&imx_ssi_fiq_start,
307 		&imx_ssi_fiq_end - &imx_ssi_fiq_start);
308 
309 	return 0;
310 }
311 
312 static void imx_pcm_free(struct snd_pcm *pcm)
313 {
314 	struct snd_pcm_substream *substream;
315 	struct snd_dma_buffer *buf;
316 	int stream;
317 
318 	for (stream = 0; stream < 2; stream++) {
319 		substream = pcm->streams[stream].substream;
320 		if (!substream)
321 			continue;
322 
323 		buf = &substream->dma_buffer;
324 		if (!buf->area)
325 			continue;
326 
327 		dma_free_wc(pcm->card->dev, buf->bytes, buf->area, buf->addr);
328 		buf->area = NULL;
329 	}
330 }
331 
332 static void imx_pcm_fiq_free(struct snd_pcm *pcm)
333 {
334 	mxc_set_irq_fiq(ssi_irq, 0);
335 	release_fiq(&fh);
336 	imx_pcm_free(pcm);
337 }
338 
339 static const struct snd_soc_component_driver imx_soc_component_fiq = {
340 	.ops		= &imx_pcm_ops,
341 	.pcm_new	= imx_pcm_fiq_new,
342 	.pcm_free	= imx_pcm_fiq_free,
343 };
344 
345 int imx_pcm_fiq_init(struct platform_device *pdev,
346 		struct imx_pcm_fiq_params *params)
347 {
348 	int ret;
349 
350 	ret = claim_fiq(&fh);
351 	if (ret) {
352 		dev_err(&pdev->dev, "failed to claim fiq: %d", ret);
353 		return ret;
354 	}
355 
356 	mxc_set_irq_fiq(params->irq, 1);
357 	ssi_irq = params->irq;
358 
359 	imx_pcm_fiq = params->irq;
360 
361 	imx_ssi_fiq_base = (unsigned long)params->base;
362 
363 	params->dma_params_tx->maxburst = 4;
364 	params->dma_params_rx->maxburst = 6;
365 
366 	ret = devm_snd_soc_register_component(&pdev->dev, &imx_soc_component_fiq,
367 					      NULL, 0);
368 	if (ret)
369 		goto failed_register;
370 
371 	return 0;
372 
373 failed_register:
374 	mxc_set_irq_fiq(ssi_irq, 0);
375 	release_fiq(&fh);
376 
377 	return ret;
378 }
379 EXPORT_SYMBOL_GPL(imx_pcm_fiq_init);
380 
381 void imx_pcm_fiq_exit(struct platform_device *pdev)
382 {
383 }
384 EXPORT_SYMBOL_GPL(imx_pcm_fiq_exit);
385 
386 MODULE_LICENSE("GPL");
387