xref: /openbmc/linux/sound/soc/au1x/dma.c (revision e23feb16)
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 
24 #define ALCHEMY_PCM_FMTS					\
25 	(SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_U8 |	\
26 	 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |	\
27 	 SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE |	\
28 	 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |	\
29 	 SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_U32_BE |	\
30 	 0)
31 
32 struct pcm_period {
33 	u32 start;
34 	u32 relative_end;	/* relative to start of buffer */
35 	struct pcm_period *next;
36 };
37 
38 struct audio_stream {
39 	struct snd_pcm_substream *substream;
40 	int dma;
41 	struct pcm_period *buffer;
42 	unsigned int period_size;
43 	unsigned int periods;
44 };
45 
46 struct alchemy_pcm_ctx {
47 	struct audio_stream stream[2];	/* playback & capture */
48 };
49 
50 static void au1000_release_dma_link(struct audio_stream *stream)
51 {
52 	struct pcm_period *pointer;
53 	struct pcm_period *pointer_next;
54 
55 	stream->period_size = 0;
56 	stream->periods = 0;
57 	pointer = stream->buffer;
58 	if (!pointer)
59 		return;
60 	do {
61 		pointer_next = pointer->next;
62 		kfree(pointer);
63 		pointer = pointer_next;
64 	} while (pointer != stream->buffer);
65 	stream->buffer = NULL;
66 }
67 
68 static int au1000_setup_dma_link(struct audio_stream *stream,
69 				 unsigned int period_bytes,
70 				 unsigned int periods)
71 {
72 	struct snd_pcm_substream *substream = stream->substream;
73 	struct snd_pcm_runtime *runtime = substream->runtime;
74 	struct pcm_period *pointer;
75 	unsigned long dma_start;
76 	int i;
77 
78 	dma_start = virt_to_phys(runtime->dma_area);
79 
80 	if (stream->period_size == period_bytes &&
81 	    stream->periods == periods)
82 		return 0; /* not changed */
83 
84 	au1000_release_dma_link(stream);
85 
86 	stream->period_size = period_bytes;
87 	stream->periods = periods;
88 
89 	stream->buffer = kmalloc(sizeof(struct pcm_period), GFP_KERNEL);
90 	if (!stream->buffer)
91 		return -ENOMEM;
92 	pointer = stream->buffer;
93 	for (i = 0; i < periods; i++) {
94 		pointer->start = (u32)(dma_start + (i * period_bytes));
95 		pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
96 		if (i < periods - 1) {
97 			pointer->next = kmalloc(sizeof(struct pcm_period),
98 						GFP_KERNEL);
99 			if (!pointer->next) {
100 				au1000_release_dma_link(stream);
101 				return -ENOMEM;
102 			}
103 			pointer = pointer->next;
104 		}
105 	}
106 	pointer->next = stream->buffer;
107 	return 0;
108 }
109 
110 static void au1000_dma_stop(struct audio_stream *stream)
111 {
112 	if (stream->buffer)
113 		disable_dma(stream->dma);
114 }
115 
116 static void au1000_dma_start(struct audio_stream *stream)
117 {
118 	if (!stream->buffer)
119 		return;
120 
121 	init_dma(stream->dma);
122 	if (get_dma_active_buffer(stream->dma) == 0) {
123 		clear_dma_done0(stream->dma);
124 		set_dma_addr0(stream->dma, stream->buffer->start);
125 		set_dma_count0(stream->dma, stream->period_size >> 1);
126 		set_dma_addr1(stream->dma, stream->buffer->next->start);
127 		set_dma_count1(stream->dma, stream->period_size >> 1);
128 	} else {
129 		clear_dma_done1(stream->dma);
130 		set_dma_addr1(stream->dma, stream->buffer->start);
131 		set_dma_count1(stream->dma, stream->period_size >> 1);
132 		set_dma_addr0(stream->dma, stream->buffer->next->start);
133 		set_dma_count0(stream->dma, stream->period_size >> 1);
134 	}
135 	enable_dma_buffers(stream->dma);
136 	start_dma(stream->dma);
137 }
138 
139 static irqreturn_t au1000_dma_interrupt(int irq, void *ptr)
140 {
141 	struct audio_stream *stream = (struct audio_stream *)ptr;
142 	struct snd_pcm_substream *substream = stream->substream;
143 
144 	switch (get_dma_buffer_done(stream->dma)) {
145 	case DMA_D0:
146 		stream->buffer = stream->buffer->next;
147 		clear_dma_done0(stream->dma);
148 		set_dma_addr0(stream->dma, stream->buffer->next->start);
149 		set_dma_count0(stream->dma, stream->period_size >> 1);
150 		enable_dma_buffer0(stream->dma);
151 		break;
152 	case DMA_D1:
153 		stream->buffer = stream->buffer->next;
154 		clear_dma_done1(stream->dma);
155 		set_dma_addr1(stream->dma, stream->buffer->next->start);
156 		set_dma_count1(stream->dma, stream->period_size >> 1);
157 		enable_dma_buffer1(stream->dma);
158 		break;
159 	case (DMA_D0 | DMA_D1):
160 		pr_debug("DMA %d missed interrupt.\n", stream->dma);
161 		au1000_dma_stop(stream);
162 		au1000_dma_start(stream);
163 		break;
164 	case (~DMA_D0 & ~DMA_D1):
165 		pr_debug("DMA %d empty irq.\n", stream->dma);
166 	}
167 	snd_pcm_period_elapsed(substream);
168 	return IRQ_HANDLED;
169 }
170 
171 static const struct snd_pcm_hardware alchemy_pcm_hardware = {
172 	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
173 			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
174 	.formats	  = ALCHEMY_PCM_FMTS,
175 	.rates		  = SNDRV_PCM_RATE_8000_192000,
176 	.rate_min	  = SNDRV_PCM_RATE_8000,
177 	.rate_max	  = SNDRV_PCM_RATE_192000,
178 	.channels_min	  = 2,
179 	.channels_max	  = 2,
180 	.period_bytes_min = 1024,
181 	.period_bytes_max = 16 * 1024 - 1,
182 	.periods_min	  = 4,
183 	.periods_max	  = 255,
184 	.buffer_bytes_max = 128 * 1024,
185 	.fifo_size	  = 16,
186 };
187 
188 static inline struct alchemy_pcm_ctx *ss_to_ctx(struct snd_pcm_substream *ss)
189 {
190 	struct snd_soc_pcm_runtime *rtd = ss->private_data;
191 	return snd_soc_platform_get_drvdata(rtd->platform);
192 }
193 
194 static inline struct audio_stream *ss_to_as(struct snd_pcm_substream *ss)
195 {
196 	struct alchemy_pcm_ctx *ctx = ss_to_ctx(ss);
197 	return &(ctx->stream[ss->stream]);
198 }
199 
200 static int alchemy_pcm_open(struct snd_pcm_substream *substream)
201 {
202 	struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
203 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
204 	int *dmaids, s = substream->stream;
205 	char *name;
206 
207 	dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
208 	if (!dmaids)
209 		return -ENODEV;	/* whoa, has ordering changed? */
210 
211 	/* DMA setup */
212 	name = (s == SNDRV_PCM_STREAM_PLAYBACK) ? "audio-tx" : "audio-rx";
213 	ctx->stream[s].dma = request_au1000_dma(dmaids[s], name,
214 					au1000_dma_interrupt, 0,
215 					&ctx->stream[s]);
216 	set_dma_mode(ctx->stream[s].dma,
217 		     get_dma_mode(ctx->stream[s].dma) & ~DMA_NC);
218 
219 	ctx->stream[s].substream = substream;
220 	ctx->stream[s].buffer = NULL;
221 	snd_soc_set_runtime_hwparams(substream, &alchemy_pcm_hardware);
222 
223 	return 0;
224 }
225 
226 static int alchemy_pcm_close(struct snd_pcm_substream *substream)
227 {
228 	struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
229 	int stype = substream->stream;
230 
231 	ctx->stream[stype].substream = NULL;
232 	free_au1000_dma(ctx->stream[stype].dma);
233 
234 	return 0;
235 }
236 
237 static int alchemy_pcm_hw_params(struct snd_pcm_substream *substream,
238 				 struct snd_pcm_hw_params *hw_params)
239 {
240 	struct audio_stream *stream = ss_to_as(substream);
241 	int err;
242 
243 	err = snd_pcm_lib_malloc_pages(substream,
244 				       params_buffer_bytes(hw_params));
245 	if (err < 0)
246 		return err;
247 	err = au1000_setup_dma_link(stream,
248 				    params_period_bytes(hw_params),
249 				    params_periods(hw_params));
250 	if (err)
251 		snd_pcm_lib_free_pages(substream);
252 
253 	return err;
254 }
255 
256 static int alchemy_pcm_hw_free(struct snd_pcm_substream *substream)
257 {
258 	struct audio_stream *stream = ss_to_as(substream);
259 	au1000_release_dma_link(stream);
260 	return snd_pcm_lib_free_pages(substream);
261 }
262 
263 static int alchemy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
264 {
265 	struct audio_stream *stream = ss_to_as(substream);
266 	int err = 0;
267 
268 	switch (cmd) {
269 	case SNDRV_PCM_TRIGGER_START:
270 		au1000_dma_start(stream);
271 		break;
272 	case SNDRV_PCM_TRIGGER_STOP:
273 		au1000_dma_stop(stream);
274 		break;
275 	default:
276 		err = -EINVAL;
277 		break;
278 	}
279 	return err;
280 }
281 
282 static snd_pcm_uframes_t alchemy_pcm_pointer(struct snd_pcm_substream *ss)
283 {
284 	struct audio_stream *stream = ss_to_as(ss);
285 	long location;
286 
287 	location = get_dma_residue(stream->dma);
288 	location = stream->buffer->relative_end - location;
289 	if (location == -1)
290 		location = 0;
291 	return bytes_to_frames(ss->runtime, location);
292 }
293 
294 static struct snd_pcm_ops alchemy_pcm_ops = {
295 	.open			= alchemy_pcm_open,
296 	.close			= alchemy_pcm_close,
297 	.ioctl			= snd_pcm_lib_ioctl,
298 	.hw_params	        = alchemy_pcm_hw_params,
299 	.hw_free	        = alchemy_pcm_hw_free,
300 	.trigger		= alchemy_pcm_trigger,
301 	.pointer		= alchemy_pcm_pointer,
302 };
303 
304 static void alchemy_pcm_free_dma_buffers(struct snd_pcm *pcm)
305 {
306 	snd_pcm_lib_preallocate_free_for_all(pcm);
307 }
308 
309 static int alchemy_pcm_new(struct snd_soc_pcm_runtime *rtd)
310 {
311 	struct snd_pcm *pcm = rtd->pcm;
312 
313 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
314 		snd_dma_continuous_data(GFP_KERNEL), 65536, (4096 * 1024) - 1);
315 
316 	return 0;
317 }
318 
319 static struct snd_soc_platform_driver alchemy_pcm_soc_platform = {
320 	.ops		= &alchemy_pcm_ops,
321 	.pcm_new	= alchemy_pcm_new,
322 	.pcm_free	= alchemy_pcm_free_dma_buffers,
323 };
324 
325 static int alchemy_pcm_drvprobe(struct platform_device *pdev)
326 {
327 	struct alchemy_pcm_ctx *ctx;
328 
329 	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
330 	if (!ctx)
331 		return -ENOMEM;
332 
333 	platform_set_drvdata(pdev, ctx);
334 
335 	return snd_soc_register_platform(&pdev->dev, &alchemy_pcm_soc_platform);
336 }
337 
338 static int alchemy_pcm_drvremove(struct platform_device *pdev)
339 {
340 	snd_soc_unregister_platform(&pdev->dev);
341 
342 	return 0;
343 }
344 
345 static struct platform_driver alchemy_pcmdma_driver = {
346 	.driver	= {
347 		.name	= "alchemy-pcm-dma",
348 		.owner	= THIS_MODULE,
349 	},
350 	.probe		= alchemy_pcm_drvprobe,
351 	.remove		= alchemy_pcm_drvremove,
352 };
353 
354 module_platform_driver(alchemy_pcmdma_driver);
355 
356 MODULE_LICENSE("GPL");
357 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
358 MODULE_AUTHOR("Manuel Lauss");
359