xref: /openbmc/linux/sound/soc/au1x/dma.c (revision e287d046)
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 
au1000_release_dma_link(struct audio_stream * stream)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 
au1000_setup_dma_link(struct audio_stream * stream,unsigned int period_bytes,unsigned int periods)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 
au1000_dma_stop(struct audio_stream * stream)105 static void au1000_dma_stop(struct audio_stream *stream)
106 {
107 	if (stream->buffer)
108 		disable_dma(stream->dma);
109 }
110 
au1000_dma_start(struct audio_stream * stream)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 
au1000_dma_interrupt(int irq,void * ptr)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 
ss_to_ctx(struct snd_pcm_substream * ss,struct snd_soc_component * component)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 
ss_to_as(struct snd_pcm_substream * ss,struct snd_soc_component * component)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 
alchemy_pcm_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 = asoc_substream_to_rtd(substream);
195 	int *dmaids, s = substream->stream;
196 	char *name;
197 
198 	dmaids = snd_soc_dai_get_dma_data(asoc_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 
alchemy_pcm_close(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 
alchemy_pcm_hw_params(struct snd_soc_component * component,struct snd_pcm_substream * substream,struct snd_pcm_hw_params * hw_params)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 
alchemy_pcm_hw_free(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 
alchemy_pcm_trigger(struct snd_soc_component * component,struct snd_pcm_substream * substream,int cmd)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 
alchemy_pcm_pointer(struct snd_soc_component * component,struct snd_pcm_substream * ss)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 
alchemy_pcm_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)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 
alchemy_pcm_drvprobe(struct platform_device * pdev)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