xref: /openbmc/linux/sound/soc/fsl/imx-pcm-fiq.c (revision 8851b9f1)
1 /*
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  *  This program is free software; you can redistribute  it and/or modify it
10  *  under  the terms of  the GNU General  Public License as published by the
11  *  Free Software Foundation;  either version 2 of the  License, or (at your
12  *  option) any later version.
13  */
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 #include <sound/core.h>
25 #include <sound/initval.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include <sound/soc.h>
29 
30 #include <asm/fiq.h>
31 
32 #include <linux/platform_data/asoc-imx-ssi.h>
33 
34 #include "imx-ssi.h"
35 
36 struct imx_pcm_runtime_data {
37 	unsigned int period;
38 	int periods;
39 	unsigned long offset;
40 	unsigned long last_offset;
41 	unsigned long size;
42 	struct hrtimer hrt;
43 	int poll_time_ns;
44 	struct snd_pcm_substream *substream;
45 	atomic_t running;
46 };
47 
48 static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
49 {
50 	struct imx_pcm_runtime_data *iprtd =
51 		container_of(hrt, struct imx_pcm_runtime_data, hrt);
52 	struct snd_pcm_substream *substream = iprtd->substream;
53 	struct snd_pcm_runtime *runtime = substream->runtime;
54 	struct pt_regs regs;
55 	unsigned long delta;
56 
57 	if (!atomic_read(&iprtd->running))
58 		return HRTIMER_NORESTART;
59 
60 	get_fiq_regs(&regs);
61 
62 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
63 		iprtd->offset = regs.ARM_r8 & 0xffff;
64 	else
65 		iprtd->offset = regs.ARM_r9 & 0xffff;
66 
67 	/* How much data have we transferred since the last period report? */
68 	if (iprtd->offset >= iprtd->last_offset)
69 		delta = iprtd->offset - iprtd->last_offset;
70 	else
71 		delta = runtime->buffer_size + iprtd->offset
72 			- iprtd->last_offset;
73 
74 	/* If we've transferred at least a period then report it and
75 	 * reset our poll time */
76 	if (delta >= iprtd->period) {
77 		snd_pcm_period_elapsed(substream);
78 		iprtd->last_offset = iprtd->offset;
79 	}
80 
81 	hrtimer_forward_now(hrt, ns_to_ktime(iprtd->poll_time_ns));
82 
83 	return HRTIMER_RESTART;
84 }
85 
86 static struct fiq_handler fh = {
87 	.name		= DRV_NAME,
88 };
89 
90 static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
91 				struct snd_pcm_hw_params *params)
92 {
93 	struct snd_pcm_runtime *runtime = substream->runtime;
94 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
95 
96 	iprtd->size = params_buffer_bytes(params);
97 	iprtd->periods = params_periods(params);
98 	iprtd->period = params_period_bytes(params) ;
99 	iprtd->offset = 0;
100 	iprtd->last_offset = 0;
101 	iprtd->poll_time_ns = 1000000000 / params_rate(params) *
102 				params_period_size(params);
103 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
104 
105 	return 0;
106 }
107 
108 static int snd_imx_pcm_prepare(struct snd_pcm_substream *substream)
109 {
110 	struct snd_pcm_runtime *runtime = substream->runtime;
111 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
112 	struct pt_regs regs;
113 
114 	get_fiq_regs(&regs);
115 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
116 		regs.ARM_r8 = (iprtd->period * iprtd->periods - 1) << 16;
117 	else
118 		regs.ARM_r9 = (iprtd->period * iprtd->periods - 1) << 16;
119 
120 	set_fiq_regs(&regs);
121 
122 	return 0;
123 }
124 
125 static int fiq_enable;
126 static int imx_pcm_fiq;
127 
128 static int snd_imx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
129 {
130 	struct snd_pcm_runtime *runtime = substream->runtime;
131 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
132 
133 	switch (cmd) {
134 	case SNDRV_PCM_TRIGGER_START:
135 	case SNDRV_PCM_TRIGGER_RESUME:
136 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
137 		atomic_set(&iprtd->running, 1);
138 		hrtimer_start(&iprtd->hrt, ns_to_ktime(iprtd->poll_time_ns),
139 		      HRTIMER_MODE_REL);
140 		if (++fiq_enable == 1)
141 			enable_fiq(imx_pcm_fiq);
142 
143 		break;
144 
145 	case SNDRV_PCM_TRIGGER_STOP:
146 	case SNDRV_PCM_TRIGGER_SUSPEND:
147 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
148 		atomic_set(&iprtd->running, 0);
149 
150 		if (--fiq_enable == 0)
151 			disable_fiq(imx_pcm_fiq);
152 
153 		break;
154 	default:
155 		return -EINVAL;
156 	}
157 
158 	return 0;
159 }
160 
161 static snd_pcm_uframes_t snd_imx_pcm_pointer(struct snd_pcm_substream *substream)
162 {
163 	struct snd_pcm_runtime *runtime = substream->runtime;
164 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
165 
166 	return bytes_to_frames(substream->runtime, iprtd->offset);
167 }
168 
169 static struct snd_pcm_hardware snd_imx_hardware = {
170 	.info = SNDRV_PCM_INFO_INTERLEAVED |
171 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
172 		SNDRV_PCM_INFO_MMAP |
173 		SNDRV_PCM_INFO_MMAP_VALID |
174 		SNDRV_PCM_INFO_PAUSE |
175 		SNDRV_PCM_INFO_RESUME,
176 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
177 	.rate_min = 8000,
178 	.channels_min = 2,
179 	.channels_max = 2,
180 	.buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
181 	.period_bytes_min = 128,
182 	.period_bytes_max = 16 * 1024,
183 	.periods_min = 4,
184 	.periods_max = 255,
185 	.fifo_size = 0,
186 };
187 
188 static int snd_imx_open(struct snd_pcm_substream *substream)
189 {
190 	struct snd_pcm_runtime *runtime = substream->runtime;
191 	struct imx_pcm_runtime_data *iprtd;
192 	int ret;
193 
194 	iprtd = kzalloc(sizeof(*iprtd), GFP_KERNEL);
195 	if (iprtd == NULL)
196 		return -ENOMEM;
197 	runtime->private_data = iprtd;
198 
199 	iprtd->substream = substream;
200 
201 	atomic_set(&iprtd->running, 0);
202 	hrtimer_init(&iprtd->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
203 	iprtd->hrt.function = snd_hrtimer_callback;
204 
205 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
206 			SNDRV_PCM_HW_PARAM_PERIODS);
207 	if (ret < 0) {
208 		kfree(iprtd);
209 		return ret;
210 	}
211 
212 	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
213 	return 0;
214 }
215 
216 static int snd_imx_close(struct snd_pcm_substream *substream)
217 {
218 	struct snd_pcm_runtime *runtime = substream->runtime;
219 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
220 
221 	hrtimer_cancel(&iprtd->hrt);
222 
223 	kfree(iprtd);
224 
225 	return 0;
226 }
227 
228 static int snd_imx_pcm_mmap(struct snd_pcm_substream *substream,
229 		struct vm_area_struct *vma)
230 {
231 	struct snd_pcm_runtime *runtime = substream->runtime;
232 	int ret;
233 
234 	ret = dma_mmap_writecombine(substream->pcm->card->dev, vma,
235 		runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
236 
237 	pr_debug("%s: ret: %d %p 0x%08x 0x%08x\n", __func__, ret,
238 			runtime->dma_area,
239 			runtime->dma_addr,
240 			runtime->dma_bytes);
241 	return ret;
242 }
243 
244 static struct snd_pcm_ops imx_pcm_ops = {
245 	.open		= snd_imx_open,
246 	.close		= snd_imx_close,
247 	.ioctl		= snd_pcm_lib_ioctl,
248 	.hw_params	= snd_imx_pcm_hw_params,
249 	.prepare	= snd_imx_pcm_prepare,
250 	.trigger	= snd_imx_pcm_trigger,
251 	.pointer	= snd_imx_pcm_pointer,
252 	.mmap		= snd_imx_pcm_mmap,
253 };
254 
255 static int imx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
256 {
257 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
258 	struct snd_dma_buffer *buf = &substream->dma_buffer;
259 	size_t size = IMX_SSI_DMABUF_SIZE;
260 
261 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
262 	buf->dev.dev = pcm->card->dev;
263 	buf->private_data = NULL;
264 	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
265 					   &buf->addr, GFP_KERNEL);
266 	if (!buf->area)
267 		return -ENOMEM;
268 	buf->bytes = size;
269 
270 	return 0;
271 }
272 
273 static u64 imx_pcm_dmamask = DMA_BIT_MASK(32);
274 
275 static int imx_pcm_new(struct snd_soc_pcm_runtime *rtd)
276 {
277 	struct snd_card *card = rtd->card->snd_card;
278 	struct snd_pcm *pcm = rtd->pcm;
279 	int ret = 0;
280 
281 	if (!card->dev->dma_mask)
282 		card->dev->dma_mask = &imx_pcm_dmamask;
283 	if (!card->dev->coherent_dma_mask)
284 		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
285 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
286 		ret = imx_pcm_preallocate_dma_buffer(pcm,
287 			SNDRV_PCM_STREAM_PLAYBACK);
288 		if (ret)
289 			goto out;
290 	}
291 
292 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
293 		ret = imx_pcm_preallocate_dma_buffer(pcm,
294 			SNDRV_PCM_STREAM_CAPTURE);
295 		if (ret)
296 			goto out;
297 	}
298 
299 out:
300 	return ret;
301 }
302 
303 static int ssi_irq = 0;
304 
305 static int imx_pcm_fiq_new(struct snd_soc_pcm_runtime *rtd)
306 {
307 	struct snd_pcm *pcm = rtd->pcm;
308 	struct snd_pcm_substream *substream;
309 	int ret;
310 
311 	ret = imx_pcm_new(rtd);
312 	if (ret)
313 		return ret;
314 
315 	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
316 	if (substream) {
317 		struct snd_dma_buffer *buf = &substream->dma_buffer;
318 
319 		imx_ssi_fiq_tx_buffer = (unsigned long)buf->area;
320 	}
321 
322 	substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
323 	if (substream) {
324 		struct snd_dma_buffer *buf = &substream->dma_buffer;
325 
326 		imx_ssi_fiq_rx_buffer = (unsigned long)buf->area;
327 	}
328 
329 	set_fiq_handler(&imx_ssi_fiq_start,
330 		&imx_ssi_fiq_end - &imx_ssi_fiq_start);
331 
332 	return 0;
333 }
334 
335 static void imx_pcm_free(struct snd_pcm *pcm)
336 {
337 	struct snd_pcm_substream *substream;
338 	struct snd_dma_buffer *buf;
339 	int stream;
340 
341 	for (stream = 0; stream < 2; stream++) {
342 		substream = pcm->streams[stream].substream;
343 		if (!substream)
344 			continue;
345 
346 		buf = &substream->dma_buffer;
347 		if (!buf->area)
348 			continue;
349 
350 		dma_free_writecombine(pcm->card->dev, buf->bytes,
351 				      buf->area, buf->addr);
352 		buf->area = NULL;
353 	}
354 }
355 
356 static void imx_pcm_fiq_free(struct snd_pcm *pcm)
357 {
358 	mxc_set_irq_fiq(ssi_irq, 0);
359 	release_fiq(&fh);
360 	imx_pcm_free(pcm);
361 }
362 
363 static struct snd_soc_platform_driver imx_soc_platform_fiq = {
364 	.ops		= &imx_pcm_ops,
365 	.pcm_new	= imx_pcm_fiq_new,
366 	.pcm_free	= imx_pcm_fiq_free,
367 };
368 
369 int imx_pcm_fiq_init(struct platform_device *pdev)
370 {
371 	struct imx_ssi *ssi = platform_get_drvdata(pdev);
372 	int ret;
373 
374 	ret = claim_fiq(&fh);
375 	if (ret) {
376 		dev_err(&pdev->dev, "failed to claim fiq: %d", ret);
377 		return ret;
378 	}
379 
380 	mxc_set_irq_fiq(ssi->irq, 1);
381 	ssi_irq = ssi->irq;
382 
383 	imx_pcm_fiq = ssi->irq;
384 
385 	imx_ssi_fiq_base = (unsigned long)ssi->base;
386 
387 	ssi->dma_params_tx.maxburst = 4;
388 	ssi->dma_params_rx.maxburst = 6;
389 
390 	ret = snd_soc_register_platform(&pdev->dev, &imx_soc_platform_fiq);
391 	if (ret)
392 		goto failed_register;
393 
394 	return 0;
395 
396 failed_register:
397 	mxc_set_irq_fiq(ssi_irq, 0);
398 	release_fiq(&fh);
399 
400 	return ret;
401 }
402 EXPORT_SYMBOL_GPL(imx_pcm_fiq_init);
403 
404 void imx_pcm_fiq_exit(struct platform_device *pdev)
405 {
406 	snd_soc_unregister_platform(&pdev->dev);
407 }
408 EXPORT_SYMBOL_GPL(imx_pcm_fiq_exit);
409