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 	 SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE | \
34 	 SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE)
35 
36 static struct kirkwood_dma_data *kirkwood_priv(struct snd_pcm_substream *subs)
37 {
38 	struct snd_soc_pcm_runtime *soc_runtime = subs->private_data;
39 	return snd_soc_dai_get_drvdata(soc_runtime->cpu_dai);
40 }
41 
42 static struct snd_pcm_hardware kirkwood_dma_snd_hw = {
43 	.info = (SNDRV_PCM_INFO_INTERLEAVED |
44 		 SNDRV_PCM_INFO_MMAP |
45 		 SNDRV_PCM_INFO_MMAP_VALID |
46 		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
47 		 SNDRV_PCM_INFO_PAUSE),
48 	.formats		= KIRKWOOD_FORMATS,
49 	.rates			= KIRKWOOD_RATES,
50 	.rate_min		= 8000,
51 	.rate_max		= 384000,
52 	.channels_min		= 1,
53 	.channels_max		= 8,
54 	.buffer_bytes_max	= KIRKWOOD_SND_MAX_BUFFER_BYTES,
55 	.period_bytes_min	= KIRKWOOD_SND_MIN_PERIOD_BYTES,
56 	.period_bytes_max	= KIRKWOOD_SND_MAX_PERIOD_BYTES,
57 	.periods_min		= KIRKWOOD_SND_MIN_PERIODS,
58 	.periods_max		= KIRKWOOD_SND_MAX_PERIODS,
59 	.fifo_size		= 0,
60 };
61 
62 static u64 kirkwood_dma_dmamask = DMA_BIT_MASK(32);
63 
64 static irqreturn_t kirkwood_dma_irq(int irq, void *dev_id)
65 {
66 	struct kirkwood_dma_data *priv = dev_id;
67 	unsigned long mask, status, cause;
68 
69 	mask = readl(priv->io + KIRKWOOD_INT_MASK);
70 	status = readl(priv->io + KIRKWOOD_INT_CAUSE) & mask;
71 
72 	cause = readl(priv->io + KIRKWOOD_ERR_CAUSE);
73 	if (unlikely(cause)) {
74 		printk(KERN_WARNING "%s: got err interrupt 0x%lx\n",
75 				__func__, cause);
76 		writel(cause, priv->io + KIRKWOOD_ERR_CAUSE);
77 	}
78 
79 	/* we've enabled only bytes interrupts ... */
80 	if (status & ~(KIRKWOOD_INT_CAUSE_PLAY_BYTES | \
81 			KIRKWOOD_INT_CAUSE_REC_BYTES)) {
82 		printk(KERN_WARNING "%s: unexpected interrupt %lx\n",
83 			__func__, status);
84 		return IRQ_NONE;
85 	}
86 
87 	/* ack int */
88 	writel(status, priv->io + KIRKWOOD_INT_CAUSE);
89 
90 	if (status & KIRKWOOD_INT_CAUSE_PLAY_BYTES)
91 		snd_pcm_period_elapsed(priv->substream_play);
92 
93 	if (status & KIRKWOOD_INT_CAUSE_REC_BYTES)
94 		snd_pcm_period_elapsed(priv->substream_rec);
95 
96 	return IRQ_HANDLED;
97 }
98 
99 static void
100 kirkwood_dma_conf_mbus_windows(void __iomem *base, int win,
101 			       unsigned long dma,
102 			       const struct mbus_dram_target_info *dram)
103 {
104 	int i;
105 
106 	/* First disable and clear windows */
107 	writel(0, base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
108 	writel(0, base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
109 
110 	/* try to find matching cs for current dma address */
111 	for (i = 0; i < dram->num_cs; i++) {
112 		const struct mbus_dram_window *cs = dram->cs + i;
113 		if ((cs->base & 0xffff0000) < (dma & 0xffff0000)) {
114 			writel(cs->base & 0xffff0000,
115 				base + KIRKWOOD_AUDIO_WIN_BASE_REG(win));
116 			writel(((cs->size - 1) & 0xffff0000) |
117 				(cs->mbus_attr << 8) |
118 				(dram->mbus_dram_target_id << 4) | 1,
119 				base + KIRKWOOD_AUDIO_WIN_CTRL_REG(win));
120 		}
121 	}
122 }
123 
124 static int kirkwood_dma_open(struct snd_pcm_substream *substream)
125 {
126 	int err;
127 	struct snd_pcm_runtime *runtime = substream->runtime;
128 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
129 	const struct mbus_dram_target_info *dram;
130 	unsigned long addr;
131 
132 	snd_soc_set_runtime_hwparams(substream, &kirkwood_dma_snd_hw);
133 
134 	/* Ensure that all constraints linked to dma burst are fulfilled */
135 	err = snd_pcm_hw_constraint_minmax(runtime,
136 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
137 			priv->burst * 2,
138 			KIRKWOOD_AUDIO_BUF_MAX-1);
139 	if (err < 0)
140 		return err;
141 
142 	err = snd_pcm_hw_constraint_step(runtime, 0,
143 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
144 			priv->burst);
145 	if (err < 0)
146 		return err;
147 
148 	err = snd_pcm_hw_constraint_step(substream->runtime, 0,
149 			 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
150 			 priv->burst);
151 	if (err < 0)
152 		return err;
153 
154 	if (!priv->substream_play && !priv->substream_rec) {
155 		err = request_irq(priv->irq, kirkwood_dma_irq, IRQF_SHARED,
156 				  "kirkwood-i2s", priv);
157 		if (err)
158 			return -EBUSY;
159 
160 		/*
161 		 * Enable Error interrupts. We're only ack'ing them but
162 		 * it's useful for diagnostics
163 		 */
164 		writel((unsigned long)-1, priv->io + KIRKWOOD_ERR_MASK);
165 	}
166 
167 	dram = mv_mbus_dram_info();
168 	addr = substream->dma_buffer.addr;
169 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
170 		priv->substream_play = substream;
171 		kirkwood_dma_conf_mbus_windows(priv->io,
172 			KIRKWOOD_PLAYBACK_WIN, addr, dram);
173 	} else {
174 		priv->substream_rec = substream;
175 		kirkwood_dma_conf_mbus_windows(priv->io,
176 			KIRKWOOD_RECORD_WIN, addr, dram);
177 	}
178 
179 	return 0;
180 }
181 
182 static int kirkwood_dma_close(struct snd_pcm_substream *substream)
183 {
184 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
185 
186 	if (!priv)
187 		return 0;
188 
189 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
190 		priv->substream_play = NULL;
191 	else
192 		priv->substream_rec = NULL;
193 
194 	if (!priv->substream_play && !priv->substream_rec) {
195 		writel(0, priv->io + KIRKWOOD_ERR_MASK);
196 		free_irq(priv->irq, priv);
197 	}
198 
199 	return 0;
200 }
201 
202 static int kirkwood_dma_hw_params(struct snd_pcm_substream *substream,
203 				struct snd_pcm_hw_params *params)
204 {
205 	struct snd_pcm_runtime *runtime = substream->runtime;
206 
207 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
208 	runtime->dma_bytes = params_buffer_bytes(params);
209 
210 	return 0;
211 }
212 
213 static int kirkwood_dma_hw_free(struct snd_pcm_substream *substream)
214 {
215 	snd_pcm_set_runtime_buffer(substream, NULL);
216 	return 0;
217 }
218 
219 static int kirkwood_dma_prepare(struct snd_pcm_substream *substream)
220 {
221 	struct snd_pcm_runtime *runtime = substream->runtime;
222 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
223 	unsigned long size, count;
224 
225 	/* compute buffer size in term of "words" as requested in specs */
226 	size = frames_to_bytes(runtime, runtime->buffer_size);
227 	size = (size>>2)-1;
228 	count = snd_pcm_lib_period_bytes(substream);
229 
230 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
231 		writel(count, priv->io + KIRKWOOD_PLAY_BYTE_INT_COUNT);
232 		writel(runtime->dma_addr, priv->io + KIRKWOOD_PLAY_BUF_ADDR);
233 		writel(size, priv->io + KIRKWOOD_PLAY_BUF_SIZE);
234 	} else {
235 		writel(count, priv->io + KIRKWOOD_REC_BYTE_INT_COUNT);
236 		writel(runtime->dma_addr, priv->io + KIRKWOOD_REC_BUF_ADDR);
237 		writel(size, priv->io + KIRKWOOD_REC_BUF_SIZE);
238 	}
239 
240 
241 	return 0;
242 }
243 
244 static snd_pcm_uframes_t kirkwood_dma_pointer(struct snd_pcm_substream
245 						*substream)
246 {
247 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
248 	snd_pcm_uframes_t count;
249 
250 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
251 		count = bytes_to_frames(substream->runtime,
252 			readl(priv->io + KIRKWOOD_PLAY_BYTE_COUNT));
253 	else
254 		count = bytes_to_frames(substream->runtime,
255 			readl(priv->io + KIRKWOOD_REC_BYTE_COUNT));
256 
257 	return count;
258 }
259 
260 static struct snd_pcm_ops kirkwood_dma_ops = {
261 	.open =		kirkwood_dma_open,
262 	.close =        kirkwood_dma_close,
263 	.ioctl =	snd_pcm_lib_ioctl,
264 	.hw_params =	kirkwood_dma_hw_params,
265 	.hw_free =      kirkwood_dma_hw_free,
266 	.prepare =      kirkwood_dma_prepare,
267 	.pointer =	kirkwood_dma_pointer,
268 };
269 
270 static int kirkwood_dma_preallocate_dma_buffer(struct snd_pcm *pcm,
271 		int stream)
272 {
273 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
274 	struct snd_dma_buffer *buf = &substream->dma_buffer;
275 	size_t size = kirkwood_dma_snd_hw.buffer_bytes_max;
276 
277 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
278 	buf->dev.dev = pcm->card->dev;
279 	buf->area = dma_alloc_coherent(pcm->card->dev, size,
280 			&buf->addr, GFP_KERNEL);
281 	if (!buf->area)
282 		return -ENOMEM;
283 	buf->bytes = size;
284 	buf->private_data = NULL;
285 
286 	return 0;
287 }
288 
289 static int kirkwood_dma_new(struct snd_soc_pcm_runtime *rtd)
290 {
291 	struct snd_card *card = rtd->card->snd_card;
292 	struct snd_pcm *pcm = rtd->pcm;
293 	int ret;
294 
295 	if (!card->dev->dma_mask)
296 		card->dev->dma_mask = &kirkwood_dma_dmamask;
297 	if (!card->dev->coherent_dma_mask)
298 		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
299 
300 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
301 		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
302 				SNDRV_PCM_STREAM_PLAYBACK);
303 		if (ret)
304 			return ret;
305 	}
306 
307 	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
308 		ret = kirkwood_dma_preallocate_dma_buffer(pcm,
309 				SNDRV_PCM_STREAM_CAPTURE);
310 		if (ret)
311 			return ret;
312 	}
313 
314 	return 0;
315 }
316 
317 static void kirkwood_dma_free_dma_buffers(struct snd_pcm *pcm)
318 {
319 	struct snd_pcm_substream *substream;
320 	struct snd_dma_buffer *buf;
321 	int stream;
322 
323 	for (stream = 0; stream < 2; stream++) {
324 		substream = pcm->streams[stream].substream;
325 		if (!substream)
326 			continue;
327 		buf = &substream->dma_buffer;
328 		if (!buf->area)
329 			continue;
330 
331 		dma_free_coherent(pcm->card->dev, buf->bytes,
332 				buf->area, buf->addr);
333 		buf->area = NULL;
334 	}
335 }
336 
337 struct snd_soc_platform_driver kirkwood_soc_platform = {
338 	.ops		= &kirkwood_dma_ops,
339 	.pcm_new	= kirkwood_dma_new,
340 	.pcm_free	= kirkwood_dma_free_dma_buffers,
341 };
342