xref: /openbmc/linux/sound/soc/au1x/dma.c (revision 275876e2)
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 struct pcm_period {
25 	u32 start;
26 	u32 relative_end;	/* relative to start of buffer */
27 	struct pcm_period *next;
28 };
29 
30 struct 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 
38 struct alchemy_pcm_ctx {
39 	struct audio_stream stream[2];	/* playback & capture */
40 };
41 
42 static 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 
60 static 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 
102 static void au1000_dma_stop(struct audio_stream *stream)
103 {
104 	if (stream->buffer)
105 		disable_dma(stream->dma);
106 }
107 
108 static 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 
131 static 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 
163 static 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 
174 static 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 
180 static 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 
186 static 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 
212 static 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 
223 static 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 
242 static 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 
249 static 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 
268 static 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 
280 static 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 
290 static void alchemy_pcm_free_dma_buffers(struct snd_pcm *pcm)
291 {
292 	snd_pcm_lib_preallocate_free_for_all(pcm);
293 }
294 
295 static int alchemy_pcm_new(struct snd_soc_pcm_runtime *rtd)
296 {
297 	struct snd_pcm *pcm = rtd->pcm;
298 
299 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
300 		snd_dma_continuous_data(GFP_KERNEL), 65536, (4096 * 1024) - 1);
301 
302 	return 0;
303 }
304 
305 static struct snd_soc_platform_driver alchemy_pcm_soc_platform = {
306 	.ops		= &alchemy_pcm_ops,
307 	.pcm_new	= alchemy_pcm_new,
308 	.pcm_free	= alchemy_pcm_free_dma_buffers,
309 };
310 
311 static int alchemy_pcm_drvprobe(struct platform_device *pdev)
312 {
313 	struct alchemy_pcm_ctx *ctx;
314 
315 	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
316 	if (!ctx)
317 		return -ENOMEM;
318 
319 	platform_set_drvdata(pdev, ctx);
320 
321 	return snd_soc_register_platform(&pdev->dev, &alchemy_pcm_soc_platform);
322 }
323 
324 static int alchemy_pcm_drvremove(struct platform_device *pdev)
325 {
326 	snd_soc_unregister_platform(&pdev->dev);
327 
328 	return 0;
329 }
330 
331 static struct platform_driver alchemy_pcmdma_driver = {
332 	.driver	= {
333 		.name	= "alchemy-pcm-dma",
334 		.owner	= THIS_MODULE,
335 	},
336 	.probe		= alchemy_pcm_drvprobe,
337 	.remove		= alchemy_pcm_drvremove,
338 };
339 
340 module_platform_driver(alchemy_pcmdma_driver);
341 
342 MODULE_LICENSE("GPL");
343 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
344 MODULE_AUTHOR("Manuel Lauss");
345