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