1/*
2 * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
3 *
4 * Author:	Nicolas Pitre
5 * Created:	Nov 30, 2004
6 * Copyright:	(C) 2004 MontaVista Software, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/device.h>
16#include <linux/slab.h>
17#include <linux/dma-mapping.h>
18
19#include <sound/driver.h>
20#include <sound/core.h>
21#include <sound/pcm.h>
22#include <sound/pcm_params.h>
23
24#include <asm/dma.h>
25#include <asm/hardware.h>
26#include <asm/arch/pxa-regs.h>
27
28#include "pxa2xx-pcm.h"
29
30
31static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
32	.info			= SNDRV_PCM_INFO_MMAP |
33				  SNDRV_PCM_INFO_MMAP_VALID |
34				  SNDRV_PCM_INFO_INTERLEAVED |
35				  SNDRV_PCM_INFO_PAUSE,
36	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
37	.period_bytes_min	= 32,
38	.period_bytes_max	= 8192 - 32,
39	.periods_min		= 1,
40	.periods_max		= PAGE_SIZE/sizeof(pxa_dma_desc),
41	.buffer_bytes_max	= 128 * 1024,
42	.fifo_size		= 32,
43};
44
45struct pxa2xx_runtime_data {
46	int dma_ch;
47	struct pxa2xx_pcm_dma_params *params;
48	pxa_dma_desc *dma_desc_array;
49	dma_addr_t dma_desc_array_phys;
50};
51
52static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
53				struct snd_pcm_hw_params *params)
54{
55	struct snd_pcm_runtime *runtime = substream->runtime;
56	struct pxa2xx_runtime_data *rtd = runtime->private_data;
57	size_t totsize = params_buffer_bytes(params);
58	size_t period = params_period_bytes(params);
59	pxa_dma_desc *dma_desc;
60	dma_addr_t dma_buff_phys, next_desc_phys;
61
62	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
63	runtime->dma_bytes = totsize;
64
65	dma_desc = rtd->dma_desc_array;
66	next_desc_phys = rtd->dma_desc_array_phys;
67	dma_buff_phys = runtime->dma_addr;
68	do {
69		next_desc_phys += sizeof(pxa_dma_desc);
70		dma_desc->ddadr = next_desc_phys;
71		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
72			dma_desc->dsadr = dma_buff_phys;
73			dma_desc->dtadr = rtd->params->dev_addr;
74		} else {
75			dma_desc->dsadr = rtd->params->dev_addr;
76			dma_desc->dtadr = dma_buff_phys;
77		}
78		if (period > totsize)
79			period = totsize;
80		dma_desc->dcmd = rtd->params->dcmd | period | DCMD_ENDIRQEN;
81		dma_desc++;
82		dma_buff_phys += period;
83	} while (totsize -= period);
84	dma_desc[-1].ddadr = rtd->dma_desc_array_phys;
85
86	return 0;
87}
88
89static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
90{
91	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
92
93	*rtd->params->drcmr = 0;
94	snd_pcm_set_runtime_buffer(substream, NULL);
95	return 0;
96}
97
98static int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
99{
100	struct pxa2xx_pcm_client *client = substream->private_data;
101	struct snd_pcm_runtime *runtime = substream->runtime;
102	struct pxa2xx_runtime_data *rtd = runtime->private_data;
103
104	DCSR(rtd->dma_ch) &= ~DCSR_RUN;
105	DCSR(rtd->dma_ch) = 0;
106	DCMD(rtd->dma_ch) = 0;
107	*rtd->params->drcmr = rtd->dma_ch | DRCMR_MAPVLD;
108
109	return client->prepare(substream);
110}
111
112static int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
113{
114	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
115	int ret = 0;
116
117	switch (cmd) {
118	case SNDRV_PCM_TRIGGER_START:
119		DDADR(rtd->dma_ch) = rtd->dma_desc_array_phys;
120		DCSR(rtd->dma_ch) = DCSR_RUN;
121		break;
122
123	case SNDRV_PCM_TRIGGER_STOP:
124	case SNDRV_PCM_TRIGGER_SUSPEND:
125	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
126		DCSR(rtd->dma_ch) &= ~DCSR_RUN;
127		break;
128
129	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
130		DCSR(rtd->dma_ch) |= DCSR_RUN;
131		break;
132
133	default:
134		ret = -EINVAL;
135	}
136
137	return ret;
138}
139
140static void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
141{
142	struct snd_pcm_substream *substream = dev_id;
143	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
144	int dcsr;
145
146	dcsr = DCSR(dma_ch);
147	DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
148
149	if (dcsr & DCSR_ENDINTR) {
150		snd_pcm_period_elapsed(substream);
151	} else {
152		printk( KERN_ERR "%s: DMA error on channel %d (DCSR=%#x)\n",
153			rtd->params->name, dma_ch, dcsr );
154		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
155	}
156}
157
158static snd_pcm_uframes_t pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
159{
160	struct snd_pcm_runtime *runtime = substream->runtime;
161	struct pxa2xx_runtime_data *rtd = runtime->private_data;
162	dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
163			 DSADR(rtd->dma_ch) : DTADR(rtd->dma_ch);
164	snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
165	if (x == runtime->buffer_size)
166		x = 0;
167	return x;
168}
169
170static int
171pxa2xx_pcm_hw_rule_mult32(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
172{
173	struct snd_interval *i = hw_param_interval(params, rule->var);
174	int changed = 0;
175
176	if (i->min & 31) {
177		i->min = (i->min & ~31) + 32;
178		i->openmin = 0;
179		changed = 1;
180	}
181
182	if (i->max & 31) {
183		i->max &= ~31;
184		i->openmax = 0;
185		changed = 1;
186	}
187
188	return changed;
189}
190
191static int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
192{
193	struct pxa2xx_pcm_client *client = substream->private_data;
194	struct snd_pcm_runtime *runtime = substream->runtime;
195	struct pxa2xx_runtime_data *rtd;
196	int ret;
197
198	runtime->hw = pxa2xx_pcm_hardware;
199
200	/*
201	 * For mysterious reasons (and despite what the manual says)
202	 * playback samples are lost if the DMA count is not a multiple
203	 * of the DMA burst size.  Let's add a rule to enforce that.
204	 */
205	ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
206				  pxa2xx_pcm_hw_rule_mult32, NULL,
207				  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1);
208	if (ret)
209		goto out;
210	ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
211				  pxa2xx_pcm_hw_rule_mult32, NULL,
212				  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, -1);
213	if (ret)
214		goto out;
215
216	ret = -ENOMEM;
217	rtd = kmalloc(sizeof(*rtd), GFP_KERNEL);
218	if (!rtd)
219		goto out;
220	rtd->dma_desc_array =
221		dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
222				       &rtd->dma_desc_array_phys, GFP_KERNEL);
223	if (!rtd->dma_desc_array)
224		goto err1;
225
226	rtd->params = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
227		      client->playback_params : client->capture_params;
228	ret = pxa_request_dma(rtd->params->name, DMA_PRIO_LOW,
229			      pxa2xx_pcm_dma_irq, substream);
230	if (ret < 0)
231		goto err2;
232	rtd->dma_ch = ret;
233
234	runtime->private_data = rtd;
235	ret = client->startup(substream);
236	if (!ret)
237		goto out;
238
239	pxa_free_dma(rtd->dma_ch);
240 err2:
241	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
242			      rtd->dma_desc_array, rtd->dma_desc_array_phys);
243 err1:
244	kfree(rtd);
245 out:
246	return ret;
247}
248
249static int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
250{
251	struct pxa2xx_pcm_client *client = substream->private_data;
252	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
253
254	pxa_free_dma(rtd->dma_ch);
255	client->shutdown(substream);
256	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
257			      rtd->dma_desc_array, rtd->dma_desc_array_phys);
258	kfree(rtd);
259	return 0;
260}
261
262static int
263pxa2xx_pcm_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *vma)
264{
265	struct snd_pcm_runtime *runtime = substream->runtime;
266	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
267				     runtime->dma_area,
268				     runtime->dma_addr,
269				     runtime->dma_bytes);
270}
271
272static struct snd_pcm_ops pxa2xx_pcm_ops = {
273	.open		= pxa2xx_pcm_open,
274	.close		= pxa2xx_pcm_close,
275	.ioctl		= snd_pcm_lib_ioctl,
276	.hw_params	= pxa2xx_pcm_hw_params,
277	.hw_free	= pxa2xx_pcm_hw_free,
278	.prepare	= pxa2xx_pcm_prepare,
279	.trigger	= pxa2xx_pcm_trigger,
280	.pointer	= pxa2xx_pcm_pointer,
281	.mmap		= pxa2xx_pcm_mmap,
282};
283
284static int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
285{
286	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
287	struct snd_dma_buffer *buf = &substream->dma_buffer;
288	size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
289	buf->dev.type = SNDRV_DMA_TYPE_DEV;
290	buf->dev.dev = pcm->card->dev;
291	buf->private_data = NULL;
292	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
293					   &buf->addr, GFP_KERNEL);
294	if (!buf->area)
295		return -ENOMEM;
296	buf->bytes = size;
297	return 0;
298}
299
300static void pxa2xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
301{
302	struct snd_pcm_substream *substream;
303	struct snd_dma_buffer *buf;
304	int stream;
305
306	for (stream = 0; stream < 2; stream++) {
307		substream = pcm->streams[stream].substream;
308		if (!substream)
309			continue;
310		buf = &substream->dma_buffer;
311		if (!buf->area)
312			continue;
313		dma_free_writecombine(pcm->card->dev, buf->bytes,
314				      buf->area, buf->addr);
315		buf->area = NULL;
316	}
317}
318
319static u64 pxa2xx_pcm_dmamask = 0xffffffff;
320
321int pxa2xx_pcm_new(struct snd_card *card, struct pxa2xx_pcm_client *client,
322		   struct snd_pcm **rpcm)
323{
324	struct snd_pcm *pcm;
325	int play = client->playback_params ? 1 : 0;
326	int capt = client->capture_params ? 1 : 0;
327	int ret;
328
329	ret = snd_pcm_new(card, "PXA2xx-PCM", 0, play, capt, &pcm);
330	if (ret)
331		goto out;
332
333	pcm->private_data = client;
334	pcm->private_free = pxa2xx_pcm_free_dma_buffers;
335
336	if (!card->dev->dma_mask)
337		card->dev->dma_mask = &pxa2xx_pcm_dmamask;
338	if (!card->dev->coherent_dma_mask)
339		card->dev->coherent_dma_mask = 0xffffffff;
340
341	if (play) {
342		int stream = SNDRV_PCM_STREAM_PLAYBACK;
343		snd_pcm_set_ops(pcm, stream, &pxa2xx_pcm_ops);
344		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm, stream);
345		if (ret)
346			goto out;
347	}
348	if (capt) {
349		int stream = SNDRV_PCM_STREAM_CAPTURE;
350		snd_pcm_set_ops(pcm, stream, &pxa2xx_pcm_ops);
351		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm, stream);
352		if (ret)
353			goto out;
354	}
355
356	if (rpcm)
357		*rpcm = pcm;
358	ret = 0;
359
360 out:
361	return ret;
362}
363
364EXPORT_SYMBOL(pxa2xx_pcm_new);
365
366MODULE_AUTHOR("Nicolas Pitre");
367MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
368MODULE_LICENSE("GPL");
369