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 
108 	snd_soc_set_runtime_hwparams(substream, &kirkwood_dma_snd_hw);
109 
110 	/* Ensure that all constraints linked to dma burst are fulfilled */
111 	err = snd_pcm_hw_constraint_minmax(runtime,
112 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
113 			priv->burst * 2,
114 			KIRKWOOD_AUDIO_BUF_MAX-1);
115 	if (err < 0)
116 		return err;
117 
118 	err = snd_pcm_hw_constraint_step(runtime, 0,
119 			SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
120 			priv->burst);
121 	if (err < 0)
122 		return err;
123 
124 	err = snd_pcm_hw_constraint_step(substream->runtime, 0,
125 			 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
126 			 priv->burst);
127 	if (err < 0)
128 		return err;
129 
130 	if (!priv->substream_play && !priv->substream_rec) {
131 		err = request_irq(priv->irq, kirkwood_dma_irq, IRQF_SHARED,
132 				  "kirkwood-i2s", priv);
133 		if (err)
134 			return err;
135 
136 		/*
137 		 * Enable Error interrupts. We're only ack'ing them but
138 		 * it's useful for diagnostics
139 		 */
140 		writel((unsigned int)-1, priv->io + KIRKWOOD_ERR_MASK);
141 	}
142 
143 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
144 		if (priv->substream_play)
145 			return -EBUSY;
146 		priv->substream_play = substream;
147 	} else {
148 		if (priv->substream_rec)
149 			return -EBUSY;
150 		priv->substream_rec = substream;
151 	}
152 
153 	return 0;
154 }
155 
156 static int kirkwood_dma_close(struct snd_soc_component *component,
157 			      struct snd_pcm_substream *substream)
158 {
159 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
160 
161 	if (!priv)
162 		return 0;
163 
164 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
165 		priv->substream_play = NULL;
166 	else
167 		priv->substream_rec = NULL;
168 
169 	if (!priv->substream_play && !priv->substream_rec) {
170 		writel(0, priv->io + KIRKWOOD_ERR_MASK);
171 		free_irq(priv->irq, priv);
172 	}
173 
174 	return 0;
175 }
176 
177 static int kirkwood_dma_hw_params(struct snd_soc_component *component,
178 				  struct snd_pcm_substream *substream,
179 				  struct snd_pcm_hw_params *params)
180 {
181 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
182 	const struct mbus_dram_target_info *dram = mv_mbus_dram_info();
183 	unsigned long addr = substream->runtime->dma_addr;
184 
185 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
186 		kirkwood_dma_conf_mbus_windows(priv->io,
187 			KIRKWOOD_PLAYBACK_WIN, addr, dram);
188 	else
189 		kirkwood_dma_conf_mbus_windows(priv->io,
190 			KIRKWOOD_RECORD_WIN, addr, dram);
191 	return 0;
192 }
193 
194 static int kirkwood_dma_prepare(struct snd_soc_component *component,
195 				struct snd_pcm_substream *substream)
196 {
197 	struct snd_pcm_runtime *runtime = substream->runtime;
198 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
199 	unsigned long size, count;
200 
201 	/* compute buffer size in term of "words" as requested in specs */
202 	size = frames_to_bytes(runtime, runtime->buffer_size);
203 	size = (size>>2)-1;
204 	count = snd_pcm_lib_period_bytes(substream);
205 
206 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
207 		writel(count, priv->io + KIRKWOOD_PLAY_BYTE_INT_COUNT);
208 		writel(runtime->dma_addr, priv->io + KIRKWOOD_PLAY_BUF_ADDR);
209 		writel(size, priv->io + KIRKWOOD_PLAY_BUF_SIZE);
210 	} else {
211 		writel(count, priv->io + KIRKWOOD_REC_BYTE_INT_COUNT);
212 		writel(runtime->dma_addr, priv->io + KIRKWOOD_REC_BUF_ADDR);
213 		writel(size, priv->io + KIRKWOOD_REC_BUF_SIZE);
214 	}
215 
216 
217 	return 0;
218 }
219 
220 static snd_pcm_uframes_t kirkwood_dma_pointer(
221 	struct snd_soc_component *component,
222 	struct snd_pcm_substream *substream)
223 {
224 	struct kirkwood_dma_data *priv = kirkwood_priv(substream);
225 	snd_pcm_uframes_t count;
226 
227 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
228 		count = bytes_to_frames(substream->runtime,
229 			readl(priv->io + KIRKWOOD_PLAY_BYTE_COUNT));
230 	else
231 		count = bytes_to_frames(substream->runtime,
232 			readl(priv->io + KIRKWOOD_REC_BYTE_COUNT));
233 
234 	return count;
235 }
236 
237 static int kirkwood_dma_new(struct snd_soc_component *component,
238 			    struct snd_soc_pcm_runtime *rtd)
239 {
240 	size_t size = kirkwood_dma_snd_hw.buffer_bytes_max;
241 	struct snd_card *card = rtd->card->snd_card;
242 	int ret;
243 
244 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
245 	if (ret)
246 		return ret;
247 
248 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
249 				       card->dev, size, size);
250 
251 	return 0;
252 }
253 
254 const struct snd_soc_component_driver kirkwood_soc_component = {
255 	.name		= DRV_NAME,
256 	.open		= kirkwood_dma_open,
257 	.close		= kirkwood_dma_close,
258 	.hw_params	= kirkwood_dma_hw_params,
259 	.prepare	= kirkwood_dma_prepare,
260 	.pointer	= kirkwood_dma_pointer,
261 	.pcm_construct	= kirkwood_dma_new,
262 };
263