1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * kirkwood-dma.c
4 *
5 * (c) 2010 Arnaud Patard <apatard@mandriva.com>
6 * (c) 2010 Arnaud Patard <arnaud.patard@rtp-net.org>
7 */
8
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/device.h>
12#include <linux/io.h>
13#include <linux/slab.h>
14#include <linux/interrupt.h>
15#include <linux/dma-mapping.h>
16#include <linux/mbus.h>
17#include <sound/soc.h>
18#include "kirkwood.h"
19
20static struct kirkwood_dma_data *kirkwood_priv(struct snd_pcm_substream *subs)
21{
22	struct snd_soc_pcm_runtime *soc_runtime = subs->private_data;
23	return snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(soc_runtime, 0));
24}
25
26static const struct snd_pcm_hardware kirkwood_dma_snd_hw = {
27	.info = SNDRV_PCM_INFO_INTERLEAVED |
28		SNDRV_PCM_INFO_MMAP |
29		SNDRV_PCM_INFO_MMAP_VALID |
30		SNDRV_PCM_INFO_BLOCK_TRANSFER |
31		SNDRV_PCM_INFO_PAUSE |
32		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP,
33	.buffer_bytes_max	= KIRKWOOD_SND_MAX_BUFFER_BYTES,
34	.period_bytes_min	= KIRKWOOD_SND_MIN_PERIOD_BYTES,
35	.period_bytes_max	= KIRKWOOD_SND_MAX_PERIOD_BYTES,
36	.periods_min		= KIRKWOOD_SND_MIN_PERIODS,
37	.periods_max		= KIRKWOOD_SND_MAX_PERIODS,
38	.fifo_size		= 0,
39};
40
41static irqreturn_t kirkwood_dma_irq(int irq, void *dev_id)
42{
43	struct kirkwood_dma_data *priv = dev_id;
44	unsigned long mask, status, cause;
45
46	mask = readl(priv->io + KIRKWOOD_INT_MASK);
47	status = readl(priv->io + KIRKWOOD_INT_CAUSE) & mask;
48
49	cause = readl(priv->io + KIRKWOOD_ERR_CAUSE);
50	if (unlikely(cause)) {
51		printk(KERN_WARNING "%s: got err interrupt 0x%lx\n",
52				__func__, cause);
53		writel(cause, priv->io + KIRKWOOD_ERR_CAUSE);
54	}
55
56	/* we've enabled only bytes interrupts ... */
57	if (status & ~(KIRKWOOD_INT_CAUSE_PLAY_BYTES | \
58			KIRKWOOD_INT_CAUSE_REC_BYTES)) {
59		printk(KERN_WARNING "%s: unexpected interrupt %lx\n",
60			__func__, status);
61		return IRQ_NONE;
62	}
63
64	/* ack int */
65	writel(status, priv->io + KIRKWOOD_INT_CAUSE);
66
67	if (status & KIRKWOOD_INT_CAUSE_PLAY_BYTES)
68		snd_pcm_period_elapsed(priv->substream_play);
69
70	if (status & KIRKWOOD_INT_CAUSE_REC_BYTES)
71		snd_pcm_period_elapsed(priv->substream_rec);
72
73	return IRQ_HANDLED;
74}
75
76static void
77kirkwood_dma_conf_mbus_windows(void __iomem *base, int win,
78			       unsigned long dma,
79			       const struct mbus_dram_target_info *dram)
80{
81	int i;
82
83	/* First disable and clear windows */
84	writel(0, base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
85	writel(0, base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
86
87	/* try to find matching cs for current dma address */
88	for (i = 0; i < dram->num_cs; i++) {
89		const struct mbus_dram_window *cs = &dram->cs[i];
90		if ((cs->base & 0xffff0000) < (dma & 0xffff0000)) {
91			writel(cs->base & 0xffff0000,
92				base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
93			writel(((cs->size - 1) & 0xffff0000) |
94				(cs->mbus_attr << 8) |
95				(dram->mbus_dram_target_id << 4) | 1,
96				base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
97		}
98	}
99}
100
101static int kirkwood_dma_open(struct snd_soc_component *component,
102			     struct snd_pcm_substream *substream)
103{
104	int err;
105	struct snd_pcm_runtime *runtime = substream->runtime;
106	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
107	const struct mbus_dram_target_info *dram;
108	unsigned long addr;
109
110	snd_soc_set_runtime_hwparams(substream, &kirkwood_dma_snd_hw);
111
112	/* Ensure that all constraints linked to dma burst are fulfilled */
113	err = snd_pcm_hw_constraint_minmax(runtime,
114			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
115			priv->burst * 2,
116			KIRKWOOD_AUDIO_BUF_MAX-1);
117	if (err < 0)
118		return err;
119
120	err = snd_pcm_hw_constraint_step(runtime, 0,
121			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
122			priv->burst);
123	if (err < 0)
124		return err;
125
126	err = snd_pcm_hw_constraint_step(substream->runtime, 0,
127			 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
128			 priv->burst);
129	if (err < 0)
130		return err;
131
132	if (!priv->substream_play && !priv->substream_rec) {
133		err = request_irq(priv->irq, kirkwood_dma_irq, IRQF_SHARED,
134				  "kirkwood-i2s", priv);
135		if (err)
136			return err;
137
138		/*
139		 * Enable Error interrupts. We're only ack'ing them but
140		 * it's useful for diagnostics
141		 */
142		writel((unsigned int)-1, priv->io + KIRKWOOD_ERR_MASK);
143	}
144
145	dram = mv_mbus_dram_info();
146	addr = substream->dma_buffer.addr;
147	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
148		if (priv->substream_play)
149			return -EBUSY;
150		priv->substream_play = substream;
151		kirkwood_dma_conf_mbus_windows(priv->io,
152			KIRKWOOD_PLAYBACK_WIN, addr, dram);
153	} else {
154		if (priv->substream_rec)
155			return -EBUSY;
156		priv->substream_rec = substream;
157		kirkwood_dma_conf_mbus_windows(priv->io,
158			KIRKWOOD_RECORD_WIN, addr, dram);
159	}
160
161	return 0;
162}
163
164static int kirkwood_dma_close(struct snd_soc_component *component,
165			      struct snd_pcm_substream *substream)
166{
167	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
168
169	if (!priv)
170		return 0;
171
172	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
173		priv->substream_play = NULL;
174	else
175		priv->substream_rec = NULL;
176
177	if (!priv->substream_play && !priv->substream_rec) {
178		writel(0, priv->io + KIRKWOOD_ERR_MASK);
179		free_irq(priv->irq, priv);
180	}
181
182	return 0;
183}
184
185static int kirkwood_dma_hw_params(struct snd_soc_component *component,
186				  struct snd_pcm_substream *substream,
187				  struct snd_pcm_hw_params *params)
188{
189	struct snd_pcm_runtime *runtime = substream->runtime;
190
191	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
192	runtime->dma_bytes = params_buffer_bytes(params);
193
194	return 0;
195}
196
197static int kirkwood_dma_hw_free(struct snd_soc_component *component,
198				struct snd_pcm_substream *substream)
199{
200	snd_pcm_set_runtime_buffer(substream, NULL);
201	return 0;
202}
203
204static int kirkwood_dma_prepare(struct snd_soc_component *component,
205				struct snd_pcm_substream *substream)
206{
207	struct snd_pcm_runtime *runtime = substream->runtime;
208	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
209	unsigned long size, count;
210
211	/* compute buffer size in term of "words" as requested in specs */
212	size = frames_to_bytes(runtime, runtime->buffer_size);
213	size = (size>>2)-1;
214	count = snd_pcm_lib_period_bytes(substream);
215
216	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
217		writel(count, priv->io + KIRKWOOD_PLAY_BYTE_INT_COUNT);
218		writel(runtime->dma_addr, priv->io + KIRKWOOD_PLAY_BUF_ADDR);
219		writel(size, priv->io + KIRKWOOD_PLAY_BUF_SIZE);
220	} else {
221		writel(count, priv->io + KIRKWOOD_REC_BYTE_INT_COUNT);
222		writel(runtime->dma_addr, priv->io + KIRKWOOD_REC_BUF_ADDR);
223		writel(size, priv->io + KIRKWOOD_REC_BUF_SIZE);
224	}
225
226
227	return 0;
228}
229
230static snd_pcm_uframes_t kirkwood_dma_pointer(
231	struct snd_soc_component *component,
232	struct snd_pcm_substream *substream)
233{
234	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
235	snd_pcm_uframes_t count;
236
237	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
238		count = bytes_to_frames(substream->runtime,
239			readl(priv->io + KIRKWOOD_PLAY_BYTE_COUNT));
240	else
241		count = bytes_to_frames(substream->runtime,
242			readl(priv->io + KIRKWOOD_REC_BYTE_COUNT));
243
244	return count;
245}
246
247static int kirkwood_dma_preallocate_dma_buffer(struct snd_pcm *pcm,
248		int stream)
249{
250	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
251	struct snd_dma_buffer *buf = &substream->dma_buffer;
252	size_t size = kirkwood_dma_snd_hw.buffer_bytes_max;
253
254	buf->dev.type = SNDRV_DMA_TYPE_DEV;
255	buf->dev.dev = pcm->card->dev;
256	buf->area = dma_alloc_coherent(pcm->card->dev, size,
257			&buf->addr, GFP_KERNEL);
258	if (!buf->area)
259		return -ENOMEM;
260	buf->bytes = size;
261	buf->private_data = NULL;
262
263	return 0;
264}
265
266static int kirkwood_dma_new(struct snd_soc_component *component,
267			    struct snd_soc_pcm_runtime *rtd)
268{
269	struct snd_card *card = rtd->card->snd_card;
270	struct snd_pcm *pcm = rtd->pcm;
271	int ret;
272
273	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
274	if (ret)
275		return ret;
276
277	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
278		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
279				SNDRV_PCM_STREAM_PLAYBACK);
280		if (ret)
281			return ret;
282	}
283
284	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
285		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
286				SNDRV_PCM_STREAM_CAPTURE);
287		if (ret)
288			return ret;
289	}
290
291	return 0;
292}
293
294static void kirkwood_dma_free_dma_buffers(struct snd_soc_component *component,
295					  struct snd_pcm *pcm)
296{
297	struct snd_pcm_substream *substream;
298	struct snd_dma_buffer *buf;
299	int stream;
300
301	for (stream = 0; stream < 2; stream++) {
302		substream = pcm->streams[stream].substream;
303		if (!substream)
304			continue;
305		buf = &substream->dma_buffer;
306		if (!buf->area)
307			continue;
308
309		dma_free_coherent(pcm->card->dev, buf->bytes,
310				buf->area, buf->addr);
311		buf->area = NULL;
312	}
313}
314
315const struct snd_soc_component_driver kirkwood_soc_component = {
316	.name		= DRV_NAME,
317	.open		= kirkwood_dma_open,
318	.close		= kirkwood_dma_close,
319	.hw_params	= kirkwood_dma_hw_params,
320	.hw_free	= kirkwood_dma_hw_free,
321	.prepare	= kirkwood_dma_prepare,
322	.pointer	= kirkwood_dma_pointer,
323	.pcm_construct	= kirkwood_dma_new,
324	.pcm_destruct	= kirkwood_dma_free_dma_buffers,
325};
326