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 #define KIRKWOOD_RATES \
25 	(SNDRV_PCM_RATE_8000_192000 |		\
26 	 SNDRV_PCM_RATE_CONTINUOUS |		\
27 	 SNDRV_PCM_RATE_KNOT)
28 
29 #define KIRKWOOD_FORMATS \
30 	(SNDRV_PCM_FMTBIT_S16_LE | \
31 	 SNDRV_PCM_FMTBIT_S24_LE | \
32 	 SNDRV_PCM_FMTBIT_S32_LE)
33 
34 static struct kirkwood_dma_data *kirkwood_priv(struct snd_pcm_substream *subs)
35 {
36 	struct snd_soc_pcm_runtime *soc_runtime = subs->private_data;
37 	return snd_soc_dai_get_drvdata(soc_runtime->cpu_dai);
38 }
39 
40 static struct snd_pcm_hardware kirkwood_dma_snd_hw = {
41 	.info = (SNDRV_PCM_INFO_INTERLEAVED |
42 		 SNDRV_PCM_INFO_MMAP |
43 		 SNDRV_PCM_INFO_MMAP_VALID |
44 		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
45 		 SNDRV_PCM_INFO_PAUSE),
46 	.formats		= KIRKWOOD_FORMATS,
47 	.rates			= KIRKWOOD_RATES,
48 	.rate_min		= 8000,
49 	.rate_max		= 384000,
50 	.channels_min		= 1,
51 	.channels_max		= 8,
52 	.buffer_bytes_max	= KIRKWOOD_SND_MAX_BUFFER_BYTES,
53 	.period_bytes_min	= KIRKWOOD_SND_MIN_PERIOD_BYTES,
54 	.period_bytes_max	= KIRKWOOD_SND_MAX_PERIOD_BYTES,
55 	.periods_min		= KIRKWOOD_SND_MIN_PERIODS,
56 	.periods_max		= KIRKWOOD_SND_MAX_PERIODS,
57 	.fifo_size		= 0,
58 };
59 
60 static irqreturn_t kirkwood_dma_irq(int irq, void *dev_id)
61 {
62 	struct kirkwood_dma_data *priv = dev_id;
63 	unsigned long mask, status, cause;
64 
65 	mask = readl(priv->io + KIRKWOOD_INT_MASK);
66 	status = readl(priv->io + KIRKWOOD_INT_CAUSE) & mask;
67 
68 	cause = readl(priv->io + KIRKWOOD_ERR_CAUSE);
69 	if (unlikely(cause)) {
70 		printk(KERN_WARNING "%s: got err interrupt 0x%lx\n",
71 				__func__, cause);
72 		writel(cause, priv->io + KIRKWOOD_ERR_CAUSE);
73 	}
74 
75 	/* we've enabled only bytes interrupts ... */
76 	if (status & ~(KIRKWOOD_INT_CAUSE_PLAY_BYTES | \
77 			KIRKWOOD_INT_CAUSE_REC_BYTES)) {
78 		printk(KERN_WARNING "%s: unexpected interrupt %lx\n",
79 			__func__, status);
80 		return IRQ_NONE;
81 	}
82 
83 	/* ack int */
84 	writel(status, priv->io + KIRKWOOD_INT_CAUSE);
85 
86 	if (status & KIRKWOOD_INT_CAUSE_PLAY_BYTES)
87 		snd_pcm_period_elapsed(priv->substream_play);
88 
89 	if (status & KIRKWOOD_INT_CAUSE_REC_BYTES)
90 		snd_pcm_period_elapsed(priv->substream_rec);
91 
92 	return IRQ_HANDLED;
93 }
94 
95 static void
96 kirkwood_dma_conf_mbus_windows(void __iomem *base, int win,
97 			       unsigned long dma,
98 			       const struct mbus_dram_target_info *dram)
99 {
100 	int i;
101 
102 	/* First disable and clear windows */
103 	writel(0, base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
104 	writel(0, base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
105 
106 	/* try to find matching cs for current dma address */
107 	for (i = 0; i < dram->num_cs; i++) {
108 		const struct mbus_dram_window *cs = dram->cs + i;
109 		if ((cs->base & 0xffff0000) < (dma & 0xffff0000)) {
110 			writel(cs->base & 0xffff0000,
111 				base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
112 			writel(((cs->size - 1) & 0xffff0000) |
113 				(cs->mbus_attr << 8) |
114 				(dram->mbus_dram_target_id << 4) | 1,
115 				base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
116 		}
117 	}
118 }
119 
120 static int kirkwood_dma_open(struct snd_pcm_substream *substream)
121 {
122 	int err;
123 	struct snd_pcm_runtime *runtime = substream->runtime;
124 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
125 	const struct mbus_dram_target_info *dram;
126 	unsigned long addr;
127 
128 	snd_soc_set_runtime_hwparams(substream, &kirkwood_dma_snd_hw);
129 
130 	/* Ensure that all constraints linked to dma burst are fulfilled */
131 	err = snd_pcm_hw_constraint_minmax(runtime,
132 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
133 			priv->burst * 2,
134 			KIRKWOOD_AUDIO_BUF_MAX-1);
135 	if (err < 0)
136 		return err;
137 
138 	err = snd_pcm_hw_constraint_step(runtime, 0,
139 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
140 			priv->burst);
141 	if (err < 0)
142 		return err;
143 
144 	err = snd_pcm_hw_constraint_step(substream->runtime, 0,
145 			 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
146 			 priv->burst);
147 	if (err < 0)
148 		return err;
149 
150 	if (!priv->substream_play && !priv->substream_rec) {
151 		err = request_irq(priv->irq, kirkwood_dma_irq, IRQF_SHARED,
152 				  "kirkwood-i2s", priv);
153 		if (err)
154 			return -EBUSY;
155 
156 		/*
157 		 * Enable Error interrupts. We're only ack'ing them but
158 		 * it's useful for diagnostics
159 		 */
160 		writel((unsigned int)-1, priv->io + KIRKWOOD_ERR_MASK);
161 	}
162 
163 	dram = mv_mbus_dram_info();
164 	addr = substream->dma_buffer.addr;
165 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
166 		priv->substream_play = substream;
167 		kirkwood_dma_conf_mbus_windows(priv->io,
168 			KIRKWOOD_PLAYBACK_WIN, addr, dram);
169 	} else {
170 		priv->substream_rec = substream;
171 		kirkwood_dma_conf_mbus_windows(priv->io,
172 			KIRKWOOD_RECORD_WIN, addr, dram);
173 	}
174 
175 	return 0;
176 }
177 
178 static int kirkwood_dma_close(struct snd_pcm_substream *substream)
179 {
180 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
181 
182 	if (!priv)
183 		return 0;
184 
185 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
186 		priv->substream_play = NULL;
187 	else
188 		priv->substream_rec = NULL;
189 
190 	if (!priv->substream_play && !priv->substream_rec) {
191 		writel(0, priv->io + KIRKWOOD_ERR_MASK);
192 		free_irq(priv->irq, priv);
193 	}
194 
195 	return 0;
196 }
197 
198 static int kirkwood_dma_hw_params(struct snd_pcm_substream *substream,
199 				struct snd_pcm_hw_params *params)
200 {
201 	struct snd_pcm_runtime *runtime = substream->runtime;
202 
203 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
204 	runtime->dma_bytes = params_buffer_bytes(params);
205 
206 	return 0;
207 }
208 
209 static int kirkwood_dma_hw_free(struct snd_pcm_substream *substream)
210 {
211 	snd_pcm_set_runtime_buffer(substream, NULL);
212 	return 0;
213 }
214 
215 static int kirkwood_dma_prepare(struct snd_pcm_substream *substream)
216 {
217 	struct snd_pcm_runtime *runtime = substream->runtime;
218 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
219 	unsigned long size, count;
220 
221 	/* compute buffer size in term of "words" as requested in specs */
222 	size = frames_to_bytes(runtime, runtime->buffer_size);
223 	size = (size>>2)-1;
224 	count = snd_pcm_lib_period_bytes(substream);
225 
226 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
227 		writel(count, priv->io + KIRKWOOD_PLAY_BYTE_INT_COUNT);
228 		writel(runtime->dma_addr, priv->io + KIRKWOOD_PLAY_BUF_ADDR);
229 		writel(size, priv->io + KIRKWOOD_PLAY_BUF_SIZE);
230 	} else {
231 		writel(count, priv->io + KIRKWOOD_REC_BYTE_INT_COUNT);
232 		writel(runtime->dma_addr, priv->io + KIRKWOOD_REC_BUF_ADDR);
233 		writel(size, priv->io + KIRKWOOD_REC_BUF_SIZE);
234 	}
235 
236 
237 	return 0;
238 }
239 
240 static snd_pcm_uframes_t kirkwood_dma_pointer(struct snd_pcm_substream
241 						*substream)
242 {
243 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
244 	snd_pcm_uframes_t count;
245 
246 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
247 		count = bytes_to_frames(substream->runtime,
248 			readl(priv->io + KIRKWOOD_PLAY_BYTE_COUNT));
249 	else
250 		count = bytes_to_frames(substream->runtime,
251 			readl(priv->io + KIRKWOOD_REC_BYTE_COUNT));
252 
253 	return count;
254 }
255 
256 static struct snd_pcm_ops kirkwood_dma_ops = {
257 	.open =		kirkwood_dma_open,
258 	.close =        kirkwood_dma_close,
259 	.ioctl =	snd_pcm_lib_ioctl,
260 	.hw_params =	kirkwood_dma_hw_params,
261 	.hw_free =      kirkwood_dma_hw_free,
262 	.prepare =      kirkwood_dma_prepare,
263 	.pointer =	kirkwood_dma_pointer,
264 };
265 
266 static int kirkwood_dma_preallocate_dma_buffer(struct snd_pcm *pcm,
267 		int stream)
268 {
269 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
270 	struct snd_dma_buffer *buf = &substream->dma_buffer;
271 	size_t size = kirkwood_dma_snd_hw.buffer_bytes_max;
272 
273 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
274 	buf->dev.dev = pcm->card->dev;
275 	buf->area = dma_alloc_coherent(pcm->card->dev, size,
276 			&buf->addr, GFP_KERNEL);
277 	if (!buf->area)
278 		return -ENOMEM;
279 	buf->bytes = size;
280 	buf->private_data = NULL;
281 
282 	return 0;
283 }
284 
285 static int kirkwood_dma_new(struct snd_soc_pcm_runtime *rtd)
286 {
287 	struct snd_card *card = rtd->card->snd_card;
288 	struct snd_pcm *pcm = rtd->pcm;
289 	int ret;
290 
291 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
292 	if (ret)
293 		return ret;
294 
295 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
296 		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
297 				SNDRV_PCM_STREAM_PLAYBACK);
298 		if (ret)
299 			return ret;
300 	}
301 
302 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
303 		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
304 				SNDRV_PCM_STREAM_CAPTURE);
305 		if (ret)
306 			return ret;
307 	}
308 
309 	return 0;
310 }
311 
312 static void kirkwood_dma_free_dma_buffers(struct snd_pcm *pcm)
313 {
314 	struct snd_pcm_substream *substream;
315 	struct snd_dma_buffer *buf;
316 	int stream;
317 
318 	for (stream = 0; stream < 2; stream++) {
319 		substream = pcm->streams[stream].substream;
320 		if (!substream)
321 			continue;
322 		buf = &substream->dma_buffer;
323 		if (!buf->area)
324 			continue;
325 
326 		dma_free_coherent(pcm->card->dev, buf->bytes,
327 				buf->area, buf->addr);
328 		buf->area = NULL;
329 	}
330 }
331 
332 struct snd_soc_platform_driver kirkwood_soc_platform = {
333 	.ops		= &kirkwood_dma_ops,
334 	.pcm_new	= kirkwood_dma_new,
335 	.pcm_free	= kirkwood_dma_free_dma_buffers,
336 };
337