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