1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Au1000/Au1500/Au1100 Audio DMA support.
4 *
5 * (c) 2011 Manuel Lauss <manuel.lauss@googlemail.com>
6 *
7 * copied almost verbatim from the old ALSA driver, written by
8 * Charles Eidsness <charles@cooper-street.com>
9 */
10
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/dma-mapping.h>
16 #include <sound/core.h>
17 #include <sound/pcm.h>
18 #include <sound/pcm_params.h>
19 #include <sound/soc.h>
20 #include <asm/mach-au1x00/au1000.h>
21 #include <asm/mach-au1x00/au1000_dma.h>
22
23 #include "psc.h"
24
25 #define DRV_NAME "au1x_dma"
26
27 struct pcm_period {
28 u32 start;
29 u32 relative_end; /* relative to start of buffer */
30 struct pcm_period *next;
31 };
32
33 struct audio_stream {
34 struct snd_pcm_substream *substream;
35 int dma;
36 struct pcm_period *buffer;
37 unsigned int period_size;
38 unsigned int periods;
39 };
40
41 struct alchemy_pcm_ctx {
42 struct audio_stream stream[2]; /* playback & capture */
43 };
44
45 static void au1000_release_dma_link(struct audio_stream *stream)
46 {
47 struct pcm_period *pointer;
48 struct pcm_period *pointer_next;
49
50 stream->period_size = 0;
51 stream->periods = 0;
52 pointer = stream->buffer;
53 if (!pointer)
54 return;
55 do {
56 pointer_next = pointer->next;
57 kfree(pointer);
58 pointer = pointer_next;
59 } while (pointer != stream->buffer);
60 stream->buffer = NULL;
61 }
62
63 static int au1000_setup_dma_link(struct audio_stream *stream,
64 unsigned int period_bytes,
65 unsigned int periods)
66 {
67 struct snd_pcm_substream *substream = stream->substream;
68 struct snd_pcm_runtime *runtime = substream->runtime;
69 struct pcm_period *pointer;
70 unsigned long dma_start;
71 int i;
72
73 dma_start = virt_to_phys(runtime->dma_area);
74
75 if (stream->period_size == period_bytes &&
76 stream->periods == periods)
77 return 0; /* not changed */
78
79 au1000_release_dma_link(stream);
80
81 stream->period_size = period_bytes;
82 stream->periods = periods;
83
84 stream->buffer = kmalloc(sizeof(struct pcm_period), GFP_KERNEL);
85 if (!stream->buffer)
86 return -ENOMEM;
87 pointer = stream->buffer;
88 for (i = 0; i < periods; i++) {
89 pointer->start = (u32)(dma_start + (i * period_bytes));
90 pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
91 if (i < periods - 1) {
92 pointer->next = kmalloc(sizeof(struct pcm_period),
93 GFP_KERNEL);
94 if (!pointer->next) {
95 au1000_release_dma_link(stream);
96 return -ENOMEM;
97 }
98 pointer = pointer->next;
99 }
100 }
101 pointer->next = stream->buffer;
102 return 0;
103 }
104
105 static void au1000_dma_stop(struct audio_stream *stream)
106 {
107 if (stream->buffer)
108 disable_dma(stream->dma);
109 }
110
111 static void au1000_dma_start(struct audio_stream *stream)
112 {
113 if (!stream->buffer)
114 return;
115
116 init_dma(stream->dma);
117 if (get_dma_active_buffer(stream->dma) == 0) {
118 clear_dma_done0(stream->dma);
119 set_dma_addr0(stream->dma, stream->buffer->start);
120 set_dma_count0(stream->dma, stream->period_size >> 1);
121 set_dma_addr1(stream->dma, stream->buffer->next->start);
122 set_dma_count1(stream->dma, stream->period_size >> 1);
123 } else {
124 clear_dma_done1(stream->dma);
125 set_dma_addr1(stream->dma, stream->buffer->start);
126 set_dma_count1(stream->dma, stream->period_size >> 1);
127 set_dma_addr0(stream->dma, stream->buffer->next->start);
128 set_dma_count0(stream->dma, stream->period_size >> 1);
129 }
130 enable_dma_buffers(stream->dma);
131 start_dma(stream->dma);
132 }
133
134 static irqreturn_t au1000_dma_interrupt(int irq, void *ptr)
135 {
136 struct audio_stream *stream = (struct audio_stream *)ptr;
137 struct snd_pcm_substream *substream = stream->substream;
138
139 switch (get_dma_buffer_done(stream->dma)) {
140 case DMA_D0:
141 stream->buffer = stream->buffer->next;
142 clear_dma_done0(stream->dma);
143 set_dma_addr0(stream->dma, stream->buffer->next->start);
144 set_dma_count0(stream->dma, stream->period_size >> 1);
145 enable_dma_buffer0(stream->dma);
146 break;
147 case DMA_D1:
148 stream->buffer = stream->buffer->next;
149 clear_dma_done1(stream->dma);
150 set_dma_addr1(stream->dma, stream->buffer->next->start);
151 set_dma_count1(stream->dma, stream->period_size >> 1);
152 enable_dma_buffer1(stream->dma);
153 break;
154 case (DMA_D0 | DMA_D1):
155 pr_debug("DMA %d missed interrupt.\n", stream->dma);
156 au1000_dma_stop(stream);
157 au1000_dma_start(stream);
158 break;
159 case (~DMA_D0 & ~DMA_D1):
160 pr_debug("DMA %d empty irq.\n", stream->dma);
161 }
162 snd_pcm_period_elapsed(substream);
163 return IRQ_HANDLED;
164 }
165
166 static const struct snd_pcm_hardware alchemy_pcm_hardware = {
167 .info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
168 SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
169 .period_bytes_min = 1024,
170 .period_bytes_max = 16 * 1024 - 1,
171 .periods_min = 4,
172 .periods_max = 255,
173 .buffer_bytes_max = 128 * 1024,
174 .fifo_size = 16,
175 };
176
177 static inline struct alchemy_pcm_ctx *ss_to_ctx(struct snd_pcm_substream *ss,
178 struct snd_soc_component *component)
179 {
180 return snd_soc_component_get_drvdata(component);
181 }
182
183 static inline struct audio_stream *ss_to_as(struct snd_pcm_substream *ss,
184 struct snd_soc_component *component)
185 {
186 struct alchemy_pcm_ctx *ctx = ss_to_ctx(ss, component);
187 return &(ctx->stream[ss->stream]);
188 }
189
190 static int alchemy_pcm_open(struct snd_soc_component *component,
191 struct snd_pcm_substream *substream)
192 {
193 struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream, component);
194 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
195 int *dmaids, s = substream->stream;
196 char *name;
197
198 dmaids = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
199 if (!dmaids)
200 return -ENODEV; /* whoa, has ordering changed? */
201
202 /* DMA setup */
203 name = (s == SNDRV_PCM_STREAM_PLAYBACK) ? "audio-tx" : "audio-rx";
204 ctx->stream[s].dma = request_au1000_dma(dmaids[s], name,
205 au1000_dma_interrupt, 0,
206 &ctx->stream[s]);
207 set_dma_mode(ctx->stream[s].dma,
208 get_dma_mode(ctx->stream[s].dma) & ~DMA_NC);
209
210 ctx->stream[s].substream = substream;
211 ctx->stream[s].buffer = NULL;
212 snd_soc_set_runtime_hwparams(substream, &alchemy_pcm_hardware);
213
214 return 0;
215 }
216
217 static int alchemy_pcm_close(struct snd_soc_component *component,
218 struct snd_pcm_substream *substream)
219 {
220 struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream, component);
221 int stype = substream->stream;
222
223 ctx->stream[stype].substream = NULL;
224 free_au1000_dma(ctx->stream[stype].dma);
225
226 return 0;
227 }
228
229 static int alchemy_pcm_hw_params(struct snd_soc_component *component,
230 struct snd_pcm_substream *substream,
231 struct snd_pcm_hw_params *hw_params)
232 {
233 struct audio_stream *stream = ss_to_as(substream, component);
234
235 return au1000_setup_dma_link(stream,
236 params_period_bytes(hw_params),
237 params_periods(hw_params));
238 }
239
240 static int alchemy_pcm_hw_free(struct snd_soc_component *component,
241 struct snd_pcm_substream *substream)
242 {
243 struct audio_stream *stream = ss_to_as(substream, component);
244 au1000_release_dma_link(stream);
245 return 0;
246 }
247
248 static int alchemy_pcm_trigger(struct snd_soc_component *component,
249 struct snd_pcm_substream *substream, int cmd)
250 {
251 struct audio_stream *stream = ss_to_as(substream, component);
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_soc_component *component,
269 struct snd_pcm_substream *ss)
270 {
271 struct audio_stream *stream = ss_to_as(ss, component);
272 long location;
273
274 location = get_dma_residue(stream->dma);
275 location = stream->buffer->relative_end - location;
276 if (location == -1)
277 location = 0;
278 return bytes_to_frames(ss->runtime, location);
279 }
280
281 static int alchemy_pcm_new(struct snd_soc_component *component,
282 struct snd_soc_pcm_runtime *rtd)
283 {
284 struct snd_pcm *pcm = rtd->pcm;
285
286 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
287 NULL, 65536, (4096 * 1024) - 1);
288
289 return 0;
290 }
291
292 static struct snd_soc_component_driver alchemy_pcm_soc_component = {
293 .name = DRV_NAME,
294 .open = alchemy_pcm_open,
295 .close = alchemy_pcm_close,
296 .hw_params = alchemy_pcm_hw_params,
297 .hw_free = alchemy_pcm_hw_free,
298 .trigger = alchemy_pcm_trigger,
299 .pointer = alchemy_pcm_pointer,
300 .pcm_construct = alchemy_pcm_new,
301 };
302
303 static int alchemy_pcm_drvprobe(struct platform_device *pdev)
304 {
305 struct alchemy_pcm_ctx *ctx;
306
307 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
308 if (!ctx)
309 return -ENOMEM;
310
311 platform_set_drvdata(pdev, ctx);
312
313 return devm_snd_soc_register_component(&pdev->dev,
314 &alchemy_pcm_soc_component, NULL, 0);
315 }
316
317 static struct platform_driver alchemy_pcmdma_driver = {
318 .driver = {
319 .name = "alchemy-pcm-dma",
320 },
321 .probe = alchemy_pcm_drvprobe,
322 };
323
324 module_platform_driver(alchemy_pcmdma_driver);
325
326 MODULE_LICENSE("GPL");
327 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
328 MODULE_AUTHOR("Manuel Lauss");
329
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