xref: /linux/sound/soc/kirkwood/kirkwood-dma.c (revision 987b741c52c7c6c68d46fbaeb95b8d1087f10b7f)
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(asoc_rtd_to_cpu(soc_runtime, 0));
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_prepare(struct snd_soc_component *component,
186 				struct snd_pcm_substream *substream)
187 {
188 	struct snd_pcm_runtime *runtime = substream->runtime;
189 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
190 	unsigned long size, count;
191 
192 	/* compute buffer size in term of "words" as requested in specs */
193 	size = frames_to_bytes(runtime, runtime->buffer_size);
194 	size = (size>>2)-1;
195 	count = snd_pcm_lib_period_bytes(substream);
196 
197 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
198 		writel(count, priv->io + KIRKWOOD_PLAY_BYTE_INT_COUNT);
199 		writel(runtime->dma_addr, priv->io + KIRKWOOD_PLAY_BUF_ADDR);
200 		writel(size, priv->io + KIRKWOOD_PLAY_BUF_SIZE);
201 	} else {
202 		writel(count, priv->io + KIRKWOOD_REC_BYTE_INT_COUNT);
203 		writel(runtime->dma_addr, priv->io + KIRKWOOD_REC_BUF_ADDR);
204 		writel(size, priv->io + KIRKWOOD_REC_BUF_SIZE);
205 	}
206 
207 
208 	return 0;
209 }
210 
211 static snd_pcm_uframes_t kirkwood_dma_pointer(
212 	struct snd_soc_component *component,
213 	struct snd_pcm_substream *substream)
214 {
215 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
216 	snd_pcm_uframes_t count;
217 
218 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
219 		count = bytes_to_frames(substream->runtime,
220 			readl(priv->io + KIRKWOOD_PLAY_BYTE_COUNT));
221 	else
222 		count = bytes_to_frames(substream->runtime,
223 			readl(priv->io + KIRKWOOD_REC_BYTE_COUNT));
224 
225 	return count;
226 }
227 
228 static int kirkwood_dma_new(struct snd_soc_component *component,
229 			    struct snd_soc_pcm_runtime *rtd)
230 {
231 	size_t size = kirkwood_dma_snd_hw.buffer_bytes_max;
232 	struct snd_card *card = rtd->card->snd_card;
233 	int ret;
234 
235 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
236 	if (ret)
237 		return ret;
238 
239 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
240 				       card->dev, size, size);
241 
242 	return 0;
243 }
244 
245 const struct snd_soc_component_driver kirkwood_soc_component = {
246 	.name		= DRV_NAME,
247 	.open		= kirkwood_dma_open,
248 	.close		= kirkwood_dma_close,
249 	.prepare	= kirkwood_dma_prepare,
250 	.pointer	= kirkwood_dma_pointer,
251 	.pcm_construct	= kirkwood_dma_new,
252 };
253