1/*
2 * Au12x0/Au1550 PSC ALSA ASoC audio support.
3 *
4 * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
5 *	Manuel Lauss <manuel.lauss@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * DMA glue for Au1x-PSC audio.
12 *
13 */
14
15
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/platform_device.h>
19#include <linux/slab.h>
20#include <linux/dma-mapping.h>
21
22#include <sound/core.h>
23#include <sound/pcm.h>
24#include <sound/pcm_params.h>
25#include <sound/soc.h>
26
27#include <asm/mach-au1x00/au1000.h>
28#include <asm/mach-au1x00/au1xxx_dbdma.h>
29#include <asm/mach-au1x00/au1xxx_psc.h>
30
31#include "psc.h"
32
33/*#define PCM_DEBUG*/
34
35#define MSG(x...)	printk(KERN_INFO "au1xpsc_pcm: " x)
36#ifdef PCM_DEBUG
37#define DBG		MSG
38#else
39#define DBG(x...)	do {} while (0)
40#endif
41
42struct au1xpsc_audio_dmadata {
43	/* DDMA control data */
44	unsigned int ddma_id;		/* DDMA direction ID for this PSC */
45	u32 ddma_chan;			/* DDMA context */
46
47	/* PCM context (for irq handlers) */
48	struct snd_pcm_substream *substream;
49	unsigned long curr_period;	/* current segment DDMA is working on */
50	unsigned long q_period;		/* queue period(s) */
51	dma_addr_t dma_area;		/* address of queued DMA area */
52	dma_addr_t dma_area_s;		/* start address of DMA area */
53	unsigned long pos;		/* current byte position being played */
54	unsigned long periods;		/* number of SG segments in total */
55	unsigned long period_bytes;	/* size in bytes of one SG segment */
56
57	/* runtime data */
58	int msbits;
59};
60
61/*
62 * These settings are somewhat okay, at least on my machine audio plays
63 * almost skip-free. Especially the 64kB buffer seems to help a LOT.
64 */
65#define AU1XPSC_PERIOD_MIN_BYTES	1024
66#define AU1XPSC_BUFFER_MIN_BYTES	65536
67
68/* PCM hardware DMA capabilities - platform specific */
69static const struct snd_pcm_hardware au1xpsc_pcm_hardware = {
70	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
71			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
72	.period_bytes_min = AU1XPSC_PERIOD_MIN_BYTES,
73	.period_bytes_max = 4096 * 1024 - 1,
74	.periods_min	  = 2,
75	.periods_max	  = 4096,	/* 2 to as-much-as-you-like */
76	.buffer_bytes_max = 4096 * 1024 - 1,
77	.fifo_size	  = 16,		/* fifo entries of AC97/I2S PSC */
78};
79
80static void au1x_pcm_queue_tx(struct au1xpsc_audio_dmadata *cd)
81{
82	au1xxx_dbdma_put_source(cd->ddma_chan, cd->dma_area,
83				cd->period_bytes, DDMA_FLAGS_IE);
84
85	/* update next-to-queue period */
86	++cd->q_period;
87	cd->dma_area += cd->period_bytes;
88	if (cd->q_period >= cd->periods) {
89		cd->q_period = 0;
90		cd->dma_area = cd->dma_area_s;
91	}
92}
93
94static void au1x_pcm_queue_rx(struct au1xpsc_audio_dmadata *cd)
95{
96	au1xxx_dbdma_put_dest(cd->ddma_chan, cd->dma_area,
97			      cd->period_bytes, DDMA_FLAGS_IE);
98
99	/* update next-to-queue period */
100	++cd->q_period;
101	cd->dma_area += cd->period_bytes;
102	if (cd->q_period >= cd->periods) {
103		cd->q_period = 0;
104		cd->dma_area = cd->dma_area_s;
105	}
106}
107
108static void au1x_pcm_dmatx_cb(int irq, void *dev_id)
109{
110	struct au1xpsc_audio_dmadata *cd = dev_id;
111
112	cd->pos += cd->period_bytes;
113	if (++cd->curr_period >= cd->periods) {
114		cd->pos = 0;
115		cd->curr_period = 0;
116	}
117	snd_pcm_period_elapsed(cd->substream);
118	au1x_pcm_queue_tx(cd);
119}
120
121static void au1x_pcm_dmarx_cb(int irq, void *dev_id)
122{
123	struct au1xpsc_audio_dmadata *cd = dev_id;
124
125	cd->pos += cd->period_bytes;
126	if (++cd->curr_period >= cd->periods) {
127		cd->pos = 0;
128		cd->curr_period = 0;
129	}
130	snd_pcm_period_elapsed(cd->substream);
131	au1x_pcm_queue_rx(cd);
132}
133
134static void au1x_pcm_dbdma_free(struct au1xpsc_audio_dmadata *pcd)
135{
136	if (pcd->ddma_chan) {
137		au1xxx_dbdma_stop(pcd->ddma_chan);
138		au1xxx_dbdma_reset(pcd->ddma_chan);
139		au1xxx_dbdma_chan_free(pcd->ddma_chan);
140		pcd->ddma_chan = 0;
141		pcd->msbits = 0;
142	}
143}
144
145/* in case of missing DMA ring or changed TX-source / RX-dest bit widths,
146 * allocate (or reallocate) a 2-descriptor DMA ring with bit depth according
147 * to ALSA-supplied sample depth.  This is due to limitations in the dbdma api
148 * (cannot adjust source/dest widths of already allocated descriptor ring).
149 */
150static int au1x_pcm_dbdma_realloc(struct au1xpsc_audio_dmadata *pcd,
151				 int stype, int msbits)
152{
153	/* DMA only in 8/16/32 bit widths */
154	if (msbits == 24)
155		msbits = 32;
156
157	/* check current config: correct bits and descriptors allocated? */
158	if ((pcd->ddma_chan) && (msbits == pcd->msbits))
159		goto out;	/* all ok! */
160
161	au1x_pcm_dbdma_free(pcd);
162
163	if (stype == SNDRV_PCM_STREAM_CAPTURE)
164		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(pcd->ddma_id,
165					DSCR_CMD0_ALWAYS,
166					au1x_pcm_dmarx_cb, (void *)pcd);
167	else
168		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(DSCR_CMD0_ALWAYS,
169					pcd->ddma_id,
170					au1x_pcm_dmatx_cb, (void *)pcd);
171
172	if (!pcd->ddma_chan)
173		return -ENOMEM;
174
175	au1xxx_dbdma_set_devwidth(pcd->ddma_chan, msbits);
176	au1xxx_dbdma_ring_alloc(pcd->ddma_chan, 2);
177
178	pcd->msbits = msbits;
179
180	au1xxx_dbdma_stop(pcd->ddma_chan);
181	au1xxx_dbdma_reset(pcd->ddma_chan);
182
183out:
184	return 0;
185}
186
187static inline struct au1xpsc_audio_dmadata *to_dmadata(struct snd_pcm_substream *ss)
188{
189	struct snd_soc_pcm_runtime *rtd = ss->private_data;
190	struct au1xpsc_audio_dmadata *pcd =
191				snd_soc_platform_get_drvdata(rtd->platform);
192	return &pcd[ss->stream];
193}
194
195static int au1xpsc_pcm_hw_params(struct snd_pcm_substream *substream,
196				 struct snd_pcm_hw_params *params)
197{
198	struct snd_pcm_runtime *runtime = substream->runtime;
199	struct au1xpsc_audio_dmadata *pcd;
200	int stype, ret;
201
202	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
203	if (ret < 0)
204		goto out;
205
206	stype = substream->stream;
207	pcd = to_dmadata(substream);
208
209	DBG("runtime->dma_area = 0x%08lx dma_addr_t = 0x%08lx dma_size = %d "
210	    "runtime->min_align %d\n",
211		(unsigned long)runtime->dma_area,
212		(unsigned long)runtime->dma_addr, runtime->dma_bytes,
213		runtime->min_align);
214
215	DBG("bits %d  frags %d  frag_bytes %d  is_rx %d\n", params->msbits,
216		params_periods(params), params_period_bytes(params), stype);
217
218	ret = au1x_pcm_dbdma_realloc(pcd, stype, params->msbits);
219	if (ret) {
220		MSG("DDMA channel (re)alloc failed!\n");
221		goto out;
222	}
223
224	pcd->substream = substream;
225	pcd->period_bytes = params_period_bytes(params);
226	pcd->periods = params_periods(params);
227	pcd->dma_area_s = pcd->dma_area = runtime->dma_addr;
228	pcd->q_period = 0;
229	pcd->curr_period = 0;
230	pcd->pos = 0;
231
232	ret = 0;
233out:
234	return ret;
235}
236
237static int au1xpsc_pcm_hw_free(struct snd_pcm_substream *substream)
238{
239	snd_pcm_lib_free_pages(substream);
240	return 0;
241}
242
243static int au1xpsc_pcm_prepare(struct snd_pcm_substream *substream)
244{
245	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
246
247	au1xxx_dbdma_reset(pcd->ddma_chan);
248
249	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
250		au1x_pcm_queue_rx(pcd);
251		au1x_pcm_queue_rx(pcd);
252	} else {
253		au1x_pcm_queue_tx(pcd);
254		au1x_pcm_queue_tx(pcd);
255	}
256
257	return 0;
258}
259
260static int au1xpsc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
261{
262	u32 c = to_dmadata(substream)->ddma_chan;
263
264	switch (cmd) {
265	case SNDRV_PCM_TRIGGER_START:
266	case SNDRV_PCM_TRIGGER_RESUME:
267		au1xxx_dbdma_start(c);
268		break;
269	case SNDRV_PCM_TRIGGER_STOP:
270	case SNDRV_PCM_TRIGGER_SUSPEND:
271		au1xxx_dbdma_stop(c);
272		break;
273	default:
274		return -EINVAL;
275	}
276	return 0;
277}
278
279static snd_pcm_uframes_t
280au1xpsc_pcm_pointer(struct snd_pcm_substream *substream)
281{
282	return bytes_to_frames(substream->runtime, to_dmadata(substream)->pos);
283}
284
285static int au1xpsc_pcm_open(struct snd_pcm_substream *substream)
286{
287	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
288	struct snd_soc_pcm_runtime *rtd = substream->private_data;
289	int stype = substream->stream, *dmaids;
290
291	dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
292	if (!dmaids)
293		return -ENODEV;	/* whoa, has ordering changed? */
294
295	pcd->ddma_id = dmaids[stype];
296
297	snd_soc_set_runtime_hwparams(substream, &au1xpsc_pcm_hardware);
298	return 0;
299}
300
301static int au1xpsc_pcm_close(struct snd_pcm_substream *substream)
302{
303	au1x_pcm_dbdma_free(to_dmadata(substream));
304	return 0;
305}
306
307static struct snd_pcm_ops au1xpsc_pcm_ops = {
308	.open		= au1xpsc_pcm_open,
309	.close		= au1xpsc_pcm_close,
310	.ioctl		= snd_pcm_lib_ioctl,
311	.hw_params	= au1xpsc_pcm_hw_params,
312	.hw_free	= au1xpsc_pcm_hw_free,
313	.prepare	= au1xpsc_pcm_prepare,
314	.trigger	= au1xpsc_pcm_trigger,
315	.pointer	= au1xpsc_pcm_pointer,
316};
317
318static int au1xpsc_pcm_new(struct snd_soc_pcm_runtime *rtd)
319{
320	struct snd_card *card = rtd->card->snd_card;
321	struct snd_pcm *pcm = rtd->pcm;
322
323	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
324		card->dev, AU1XPSC_BUFFER_MIN_BYTES, (4096 * 1024) - 1);
325
326	return 0;
327}
328
329/* au1xpsc audio platform */
330static struct snd_soc_platform_driver au1xpsc_soc_platform = {
331	.ops		= &au1xpsc_pcm_ops,
332	.pcm_new	= au1xpsc_pcm_new,
333};
334
335static int au1xpsc_pcm_drvprobe(struct platform_device *pdev)
336{
337	struct au1xpsc_audio_dmadata *dmadata;
338
339	dmadata = devm_kzalloc(&pdev->dev,
340			       2 * sizeof(struct au1xpsc_audio_dmadata),
341			       GFP_KERNEL);
342	if (!dmadata)
343		return -ENOMEM;
344
345	platform_set_drvdata(pdev, dmadata);
346
347	return devm_snd_soc_register_platform(&pdev->dev,
348					      &au1xpsc_soc_platform);
349}
350
351static struct platform_driver au1xpsc_pcm_driver = {
352	.driver	= {
353		.name	= "au1xpsc-pcm",
354	},
355	.probe		= au1xpsc_pcm_drvprobe,
356};
357
358module_platform_driver(au1xpsc_pcm_driver);
359
360MODULE_LICENSE("GPL");
361MODULE_DESCRIPTION("Au12x0/Au1550 PSC Audio DMA driver");
362MODULE_AUTHOR("Manuel Lauss");
363