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 
20 static 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(soc_runtime->cpu_dai);
24 }
25 
26 static 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 
41 static 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 
76 static void
77 kirkwood_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 
101 static 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 
164 static 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 
185 static 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 
197 static 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 
204 static 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 
230 static 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 
247 static 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 
266 static 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 
294 static 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 
315 const struct snd_soc_component_driver kirkwood_soc_component = {
316 	.name		= DRV_NAME,
317 	.open		= kirkwood_dma_open,
318 	.close		= kirkwood_dma_close,
319 	.ioctl		= snd_soc_pcm_lib_ioctl,
320 	.hw_params	= kirkwood_dma_hw_params,
321 	.hw_free	= kirkwood_dma_hw_free,
322 	.prepare	= kirkwood_dma_prepare,
323 	.pointer	= kirkwood_dma_pointer,
324 	.pcm_construct	= kirkwood_dma_new,
325 	.pcm_destruct	= kirkwood_dma_free_dma_buffers,
326 };
327