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