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Linux/sound/soc/au1x/dma.c

  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 

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