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
27struct pcm_period {
28	u32 start;
29	u32 relative_end;	/* relative to start of buffer */
30	struct pcm_period *next;
31};
32
33struct 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
41struct alchemy_pcm_ctx {
42	struct audio_stream stream[2];	/* playback & capture */
43};
44
45static 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
63static 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
105static void au1000_dma_stop(struct audio_stream *stream)
106{
107	if (stream->buffer)
108		disable_dma(stream->dma);
109}
110
111static 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
134static 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
166static 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
177static 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
183static 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
190static 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
217static 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
229static 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
240static 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
248static 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
268static 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
281static 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
292static 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
303static 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
317static struct platform_driver alchemy_pcmdma_driver = {
318	.driver	= {
319		.name	= "alchemy-pcm-dma",
320	},
321	.probe		= alchemy_pcm_drvprobe,
322};
323
324module_platform_driver(alchemy_pcmdma_driver);
325
326MODULE_LICENSE("GPL");
327MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
328MODULE_AUTHOR("Manuel Lauss");
329