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
au1000_release_dma_link(struct audio_stream * stream)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
au1000_setup_dma_link(struct audio_stream * stream,unsigned int period_bytes,unsigned int periods)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
au1000_dma_stop(struct audio_stream * stream)102 static void au1000_dma_stop(struct audio_stream *stream)
103 {
104 if (stream->buffer)
105 disable_dma(stream->dma);
106 }
107
au1000_dma_start(struct audio_stream * stream)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
au1000_dma_interrupt(int irq,void * ptr)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
ss_to_ctx(struct snd_pcm_substream * ss)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
ss_to_as(struct snd_pcm_substream * ss)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
alchemy_pcm_open(struct snd_pcm_substream * substream)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
alchemy_pcm_close(struct snd_pcm_substream * substream)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
alchemy_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * hw_params)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
alchemy_pcm_hw_free(struct snd_pcm_substream * substream)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
alchemy_pcm_trigger(struct snd_pcm_substream * substream,int cmd)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
alchemy_pcm_pointer(struct snd_pcm_substream * ss)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
alchemy_pcm_new(struct snd_soc_pcm_runtime * rtd)290 static 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
300 static struct snd_soc_platform_driver alchemy_pcm_soc_platform = {
301 .ops = &alchemy_pcm_ops,
302 .pcm_new = alchemy_pcm_new,
303 };
304
alchemy_pcm_drvprobe(struct platform_device * pdev)305 static 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 devm_snd_soc_register_platform(&pdev->dev,
316 &alchemy_pcm_soc_platform);
317 }
318
319 static struct platform_driver alchemy_pcmdma_driver = {
320 .driver = {
321 .name = "alchemy-pcm-dma",
322 },
323 .probe = alchemy_pcm_drvprobe,
324 };
325
326 module_platform_driver(alchemy_pcmdma_driver);
327
328 MODULE_LICENSE("GPL");
329 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
330 MODULE_AUTHOR("Manuel Lauss");
331