1/*
2 * Au1000/Au1500/Au1100 Audio DMA support.
3 *
4 * (c) 2011 Manuel Lauss <manuel.lauss@googlemail.com>
5 *
6 * copied almost verbatim from the old ALSA driver, written by
7 *			Charles Eidsness <charles@cooper-street.com>
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/dma-mapping.h>
15#include <sound/core.h>
16#include <sound/pcm.h>
17#include <sound/pcm_params.h>
18#include <sound/soc.h>
19#include <asm/mach-au1x00/au1000.h>
20#include <asm/mach-au1x00/au1000_dma.h>
21
22#include "psc.h"
23
24struct pcm_period {
25	u32 start;
26	u32 relative_end;	/* relative to start of buffer */
27	struct pcm_period *next;
28};
29
30struct audio_stream {
31	struct snd_pcm_substream *substream;
32	int dma;
33	struct pcm_period *buffer;
34	unsigned int period_size;
35	unsigned int periods;
36};
37
38struct alchemy_pcm_ctx {
39	struct audio_stream stream[2];	/* playback & capture */
40};
41
42static void au1000_release_dma_link(struct audio_stream *stream)
43{
44	struct pcm_period *pointer;
45	struct pcm_period *pointer_next;
46
47	stream->period_size = 0;
48	stream->periods = 0;
49	pointer = stream->buffer;
50	if (!pointer)
51		return;
52	do {
53		pointer_next = pointer->next;
54		kfree(pointer);
55		pointer = pointer_next;
56	} while (pointer != stream->buffer);
57	stream->buffer = NULL;
58}
59
60static int au1000_setup_dma_link(struct audio_stream *stream,
61				 unsigned int period_bytes,
62				 unsigned int periods)
63{
64	struct snd_pcm_substream *substream = stream->substream;
65	struct snd_pcm_runtime *runtime = substream->runtime;
66	struct pcm_period *pointer;
67	unsigned long dma_start;
68	int i;
69
70	dma_start = virt_to_phys(runtime->dma_area);
71
72	if (stream->period_size == period_bytes &&
73	    stream->periods == periods)
74		return 0; /* not changed */
75
76	au1000_release_dma_link(stream);
77
78	stream->period_size = period_bytes;
79	stream->periods = periods;
80
81	stream->buffer = kmalloc(sizeof(struct pcm_period), GFP_KERNEL);
82	if (!stream->buffer)
83		return -ENOMEM;
84	pointer = stream->buffer;
85	for (i = 0; i < periods; i++) {
86		pointer->start = (u32)(dma_start + (i * period_bytes));
87		pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
88		if (i < periods - 1) {
89			pointer->next = kmalloc(sizeof(struct pcm_period),
90						GFP_KERNEL);
91			if (!pointer->next) {
92				au1000_release_dma_link(stream);
93				return -ENOMEM;
94			}
95			pointer = pointer->next;
96		}
97	}
98	pointer->next = stream->buffer;
99	return 0;
100}
101
102static void au1000_dma_stop(struct audio_stream *stream)
103{
104	if (stream->buffer)
105		disable_dma(stream->dma);
106}
107
108static void au1000_dma_start(struct audio_stream *stream)
109{
110	if (!stream->buffer)
111		return;
112
113	init_dma(stream->dma);
114	if (get_dma_active_buffer(stream->dma) == 0) {
115		clear_dma_done0(stream->dma);
116		set_dma_addr0(stream->dma, stream->buffer->start);
117		set_dma_count0(stream->dma, stream->period_size >> 1);
118		set_dma_addr1(stream->dma, stream->buffer->next->start);
119		set_dma_count1(stream->dma, stream->period_size >> 1);
120	} else {
121		clear_dma_done1(stream->dma);
122		set_dma_addr1(stream->dma, stream->buffer->start);
123		set_dma_count1(stream->dma, stream->period_size >> 1);
124		set_dma_addr0(stream->dma, stream->buffer->next->start);
125		set_dma_count0(stream->dma, stream->period_size >> 1);
126	}
127	enable_dma_buffers(stream->dma);
128	start_dma(stream->dma);
129}
130
131static irqreturn_t au1000_dma_interrupt(int irq, void *ptr)
132{
133	struct audio_stream *stream = (struct audio_stream *)ptr;
134	struct snd_pcm_substream *substream = stream->substream;
135
136	switch (get_dma_buffer_done(stream->dma)) {
137	case DMA_D0:
138		stream->buffer = stream->buffer->next;
139		clear_dma_done0(stream->dma);
140		set_dma_addr0(stream->dma, stream->buffer->next->start);
141		set_dma_count0(stream->dma, stream->period_size >> 1);
142		enable_dma_buffer0(stream->dma);
143		break;
144	case DMA_D1:
145		stream->buffer = stream->buffer->next;
146		clear_dma_done1(stream->dma);
147		set_dma_addr1(stream->dma, stream->buffer->next->start);
148		set_dma_count1(stream->dma, stream->period_size >> 1);
149		enable_dma_buffer1(stream->dma);
150		break;
151	case (DMA_D0 | DMA_D1):
152		pr_debug("DMA %d missed interrupt.\n", stream->dma);
153		au1000_dma_stop(stream);
154		au1000_dma_start(stream);
155		break;
156	case (~DMA_D0 & ~DMA_D1):
157		pr_debug("DMA %d empty irq.\n", stream->dma);
158	}
159	snd_pcm_period_elapsed(substream);
160	return IRQ_HANDLED;
161}
162
163static const struct snd_pcm_hardware alchemy_pcm_hardware = {
164	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
165			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
166	.period_bytes_min = 1024,
167	.period_bytes_max = 16 * 1024 - 1,
168	.periods_min	  = 4,
169	.periods_max	  = 255,
170	.buffer_bytes_max = 128 * 1024,
171	.fifo_size	  = 16,
172};
173
174static inline struct alchemy_pcm_ctx *ss_to_ctx(struct snd_pcm_substream *ss)
175{
176	struct snd_soc_pcm_runtime *rtd = ss->private_data;
177	return snd_soc_platform_get_drvdata(rtd->platform);
178}
179
180static inline struct audio_stream *ss_to_as(struct snd_pcm_substream *ss)
181{
182	struct alchemy_pcm_ctx *ctx = ss_to_ctx(ss);
183	return &(ctx->stream[ss->stream]);
184}
185
186static int alchemy_pcm_open(struct snd_pcm_substream *substream)
187{
188	struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
189	struct snd_soc_pcm_runtime *rtd = substream->private_data;
190	int *dmaids, s = substream->stream;
191	char *name;
192
193	dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
194	if (!dmaids)
195		return -ENODEV;	/* whoa, has ordering changed? */
196
197	/* DMA setup */
198	name = (s == SNDRV_PCM_STREAM_PLAYBACK) ? "audio-tx" : "audio-rx";
199	ctx->stream[s].dma = request_au1000_dma(dmaids[s], name,
200					au1000_dma_interrupt, 0,
201					&ctx->stream[s]);
202	set_dma_mode(ctx->stream[s].dma,
203		     get_dma_mode(ctx->stream[s].dma) & ~DMA_NC);
204
205	ctx->stream[s].substream = substream;
206	ctx->stream[s].buffer = NULL;
207	snd_soc_set_runtime_hwparams(substream, &alchemy_pcm_hardware);
208
209	return 0;
210}
211
212static int alchemy_pcm_close(struct snd_pcm_substream *substream)
213{
214	struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
215	int stype = substream->stream;
216
217	ctx->stream[stype].substream = NULL;
218	free_au1000_dma(ctx->stream[stype].dma);
219
220	return 0;
221}
222
223static int alchemy_pcm_hw_params(struct snd_pcm_substream *substream,
224				 struct snd_pcm_hw_params *hw_params)
225{
226	struct audio_stream *stream = ss_to_as(substream);
227	int err;
228
229	err = snd_pcm_lib_malloc_pages(substream,
230				       params_buffer_bytes(hw_params));
231	if (err < 0)
232		return err;
233	err = au1000_setup_dma_link(stream,
234				    params_period_bytes(hw_params),
235				    params_periods(hw_params));
236	if (err)
237		snd_pcm_lib_free_pages(substream);
238
239	return err;
240}
241
242static int alchemy_pcm_hw_free(struct snd_pcm_substream *substream)
243{
244	struct audio_stream *stream = ss_to_as(substream);
245	au1000_release_dma_link(stream);
246	return snd_pcm_lib_free_pages(substream);
247}
248
249static int alchemy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
250{
251	struct audio_stream *stream = ss_to_as(substream);
252	int err = 0;
253
254	switch (cmd) {
255	case SNDRV_PCM_TRIGGER_START:
256		au1000_dma_start(stream);
257		break;
258	case SNDRV_PCM_TRIGGER_STOP:
259		au1000_dma_stop(stream);
260		break;
261	default:
262		err = -EINVAL;
263		break;
264	}
265	return err;
266}
267
268static snd_pcm_uframes_t alchemy_pcm_pointer(struct snd_pcm_substream *ss)
269{
270	struct audio_stream *stream = ss_to_as(ss);
271	long location;
272
273	location = get_dma_residue(stream->dma);
274	location = stream->buffer->relative_end - location;
275	if (location == -1)
276		location = 0;
277	return bytes_to_frames(ss->runtime, location);
278}
279
280static struct snd_pcm_ops alchemy_pcm_ops = {
281	.open			= alchemy_pcm_open,
282	.close			= alchemy_pcm_close,
283	.ioctl			= snd_pcm_lib_ioctl,
284	.hw_params	        = alchemy_pcm_hw_params,
285	.hw_free	        = alchemy_pcm_hw_free,
286	.trigger		= alchemy_pcm_trigger,
287	.pointer		= alchemy_pcm_pointer,
288};
289
290static int alchemy_pcm_new(struct snd_soc_pcm_runtime *rtd)
291{
292	struct snd_pcm *pcm = rtd->pcm;
293
294	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
295		snd_dma_continuous_data(GFP_KERNEL), 65536, (4096 * 1024) - 1);
296
297	return 0;
298}
299
300static struct snd_soc_platform_driver alchemy_pcm_soc_platform = {
301	.ops		= &alchemy_pcm_ops,
302	.pcm_new	= alchemy_pcm_new,
303};
304
305static int alchemy_pcm_drvprobe(struct platform_device *pdev)
306{
307	struct alchemy_pcm_ctx *ctx;
308
309	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
310	if (!ctx)
311		return -ENOMEM;
312
313	platform_set_drvdata(pdev, ctx);
314
315	return snd_soc_register_platform(&pdev->dev, &alchemy_pcm_soc_platform);
316}
317
318static int alchemy_pcm_drvremove(struct platform_device *pdev)
319{
320	snd_soc_unregister_platform(&pdev->dev);
321
322	return 0;
323}
324
325static struct platform_driver alchemy_pcmdma_driver = {
326	.driver	= {
327		.name	= "alchemy-pcm-dma",
328	},
329	.probe		= alchemy_pcm_drvprobe,
330	.remove		= alchemy_pcm_drvremove,
331};
332
333module_platform_driver(alchemy_pcmdma_driver);
334
335MODULE_LICENSE("GPL");
336MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
337MODULE_AUTHOR("Manuel Lauss");
338