xref: /linux/sound/soc/sti/uniperif_reader.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * Copyright (C) STMicroelectronics SA 2015
3  * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
4  *          for STMicroelectronics.
5  * License terms:  GNU General Public License (GPL), version 2
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 
12 #include <sound/soc.h>
13 
14 #include "uniperif.h"
15 
16 /*
17  * Note: snd_pcm_hardware is linked to DMA controller but is declared here to
18  * integrate unireader capability in term of rate and supported channels
19  */
20 static const struct snd_pcm_hardware uni_reader_pcm_hw = {
21 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
22 		SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
23 		SNDRV_PCM_INFO_MMAP_VALID,
24 	.formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE,
25 
26 	.rates = SNDRV_PCM_RATE_CONTINUOUS,
27 	.rate_min = 8000,
28 	.rate_max = 96000,
29 
30 	.channels_min = 2,
31 	.channels_max = 8,
32 
33 	.periods_min = 2,
34 	.periods_max = 48,
35 
36 	.period_bytes_min = 128,
37 	.period_bytes_max = 64 * PAGE_SIZE,
38 	.buffer_bytes_max = 256 * PAGE_SIZE
39 };
40 
41 /*
42  * uni_reader_irq_handler
43  * In case of error audio stream is stopped; stop action is protected via PCM
44  * stream lock  to avoid race condition with trigger callback.
45  */
46 static irqreturn_t uni_reader_irq_handler(int irq, void *dev_id)
47 {
48 	irqreturn_t ret = IRQ_NONE;
49 	struct uniperif *reader = dev_id;
50 	unsigned int status;
51 
52 	if (reader->state == UNIPERIF_STATE_STOPPED) {
53 		/* Unexpected IRQ: do nothing */
54 		dev_warn(reader->dev, "unexpected IRQ ");
55 		return IRQ_HANDLED;
56 	}
57 
58 	/* Get interrupt status & clear them immediately */
59 	status = GET_UNIPERIF_ITS(reader);
60 	SET_UNIPERIF_ITS_BCLR(reader, status);
61 
62 	/* Check for fifo overflow error */
63 	if (unlikely(status & UNIPERIF_ITS_FIFO_ERROR_MASK(reader))) {
64 		dev_err(reader->dev, "FIFO error detected");
65 
66 		snd_pcm_stream_lock(reader->substream);
67 		snd_pcm_stop(reader->substream, SNDRV_PCM_STATE_XRUN);
68 		snd_pcm_stream_unlock(reader->substream);
69 
70 		return IRQ_HANDLED;
71 	}
72 
73 	return ret;
74 }
75 
76 static int uni_reader_prepare(struct snd_pcm_substream *substream,
77 			      struct snd_soc_dai *dai)
78 {
79 	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
80 	struct uniperif *reader = priv->dai_data.uni;
81 	struct snd_pcm_runtime *runtime = substream->runtime;
82 	int transfer_size, trigger_limit;
83 	int slot_width;
84 	int count = 10;
85 
86 	/* The reader should be stopped */
87 	if (reader->state != UNIPERIF_STATE_STOPPED) {
88 		dev_err(reader->dev, "%s: invalid reader state %d", __func__,
89 			reader->state);
90 		return -EINVAL;
91 	}
92 
93 	/* Calculate transfer size (in fifo cells and bytes) for frame count */
94 	transfer_size = runtime->channels * UNIPERIF_FIFO_FRAMES;
95 
96 	/* Calculate number of empty cells available before asserting DREQ */
97 	if (reader->ver < SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0)
98 		trigger_limit = UNIPERIF_FIFO_SIZE - transfer_size;
99 	else
100 		/*
101 		 * Since SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0
102 		 * FDMA_TRIGGER_LIMIT also controls when the state switches
103 		 * from OFF or STANDBY to AUDIO DATA.
104 		 */
105 		trigger_limit = transfer_size;
106 
107 	/* Trigger limit must be an even number */
108 	if ((!trigger_limit % 2) ||
109 	    (trigger_limit != 1 && transfer_size % 2) ||
110 	    (trigger_limit > UNIPERIF_CONFIG_DMA_TRIG_LIMIT_MASK(reader))) {
111 		dev_err(reader->dev, "invalid trigger limit %d", trigger_limit);
112 		return -EINVAL;
113 	}
114 
115 	SET_UNIPERIF_CONFIG_DMA_TRIG_LIMIT(reader, trigger_limit);
116 
117 	switch (reader->daifmt & SND_SOC_DAIFMT_INV_MASK) {
118 	case SND_SOC_DAIFMT_IB_IF:
119 	case SND_SOC_DAIFMT_NB_IF:
120 		SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
121 		break;
122 	default:
123 		SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
124 	}
125 
126 	/* Force slot width to 32 in I2S mode */
127 	if ((reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK)
128 		== SND_SOC_DAIFMT_I2S) {
129 		slot_width = 32;
130 	} else {
131 		switch (runtime->format) {
132 		case SNDRV_PCM_FORMAT_S16_LE:
133 			slot_width = 16;
134 			break;
135 		default:
136 			slot_width = 32;
137 			break;
138 		}
139 	}
140 
141 	/* Number of bits per subframe (i.e one channel sample) on input. */
142 	switch (slot_width) {
143 	case 32:
144 		SET_UNIPERIF_I2S_FMT_NBIT_32(reader);
145 		SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(reader);
146 		break;
147 	case 16:
148 		SET_UNIPERIF_I2S_FMT_NBIT_16(reader);
149 		SET_UNIPERIF_I2S_FMT_DATA_SIZE_16(reader);
150 		break;
151 	default:
152 		dev_err(reader->dev, "subframe format not supported");
153 		return -EINVAL;
154 	}
155 
156 	/* Configure data memory format */
157 	switch (runtime->format) {
158 	case SNDRV_PCM_FORMAT_S16_LE:
159 		/* One data word contains two samples */
160 		SET_UNIPERIF_CONFIG_MEM_FMT_16_16(reader);
161 		break;
162 
163 	case SNDRV_PCM_FORMAT_S32_LE:
164 		/*
165 		 * Actually "16 bits/0 bits" means "32/28/24/20/18/16 bits
166 		 * on the MSB then zeros (if less than 32 bytes)"...
167 		 */
168 		SET_UNIPERIF_CONFIG_MEM_FMT_16_0(reader);
169 		break;
170 
171 	default:
172 		dev_err(reader->dev, "format not supported");
173 		return -EINVAL;
174 	}
175 
176 	switch (reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
177 	case SND_SOC_DAIFMT_I2S:
178 		SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
179 		SET_UNIPERIF_I2S_FMT_PADDING_I2S_MODE(reader);
180 		break;
181 	case SND_SOC_DAIFMT_LEFT_J:
182 		SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
183 		SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
184 		break;
185 	case SND_SOC_DAIFMT_RIGHT_J:
186 		SET_UNIPERIF_I2S_FMT_ALIGN_RIGHT(reader);
187 		SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
188 		break;
189 	default:
190 		dev_err(reader->dev, "format not supported");
191 		return -EINVAL;
192 	}
193 
194 	SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);
195 
196 	/* Data clocking (changing) on the rising edge */
197 	SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
198 
199 	/* Number of channels must be even */
200 
201 	if ((runtime->channels % 2) || (runtime->channels < 2) ||
202 	    (runtime->channels > 10)) {
203 		dev_err(reader->dev, "%s: invalid nb of channels", __func__);
204 		return -EINVAL;
205 	}
206 
207 	SET_UNIPERIF_I2S_FMT_NUM_CH(reader, runtime->channels / 2);
208 
209 	/* Clear any pending interrupts */
210 	SET_UNIPERIF_ITS_BCLR(reader, GET_UNIPERIF_ITS(reader));
211 
212 	SET_UNIPERIF_I2S_FMT_NO_OF_SAMPLES_TO_READ(reader, 0);
213 
214 	/* Set the interrupt mask */
215 	SET_UNIPERIF_ITM_BSET_DMA_ERROR(reader);
216 	SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);
217 	SET_UNIPERIF_ITM_BSET_MEM_BLK_READ(reader);
218 
219 	/* Enable underflow recovery interrupts */
220 	if (reader->info->underflow_enabled) {
221 		SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_DONE(reader);
222 		SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_FAILED(reader);
223 	}
224 
225 	/* Reset uniperipheral reader */
226 	SET_UNIPERIF_SOFT_RST_SOFT_RST(reader);
227 
228 	while (GET_UNIPERIF_SOFT_RST_SOFT_RST(reader)) {
229 		udelay(5);
230 		count--;
231 	}
232 	if (!count) {
233 		dev_err(reader->dev, "Failed to reset uniperif");
234 		return -EIO;
235 	}
236 
237 	return 0;
238 }
239 
240 static int uni_reader_start(struct uniperif *reader)
241 {
242 	/* The reader should be stopped */
243 	if (reader->state != UNIPERIF_STATE_STOPPED) {
244 		dev_err(reader->dev, "%s: invalid reader state", __func__);
245 		return -EINVAL;
246 	}
247 
248 	/* Enable reader interrupts (and clear possible stalled ones) */
249 	SET_UNIPERIF_ITS_BCLR_FIFO_ERROR(reader);
250 	SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);
251 
252 	/* Launch the reader */
253 	SET_UNIPERIF_CTRL_OPERATION_PCM_DATA(reader);
254 
255 	/* Update state to started */
256 	reader->state = UNIPERIF_STATE_STARTED;
257 	return 0;
258 }
259 
260 static int uni_reader_stop(struct uniperif *reader)
261 {
262 	/* The reader should not be in stopped state */
263 	if (reader->state == UNIPERIF_STATE_STOPPED) {
264 		dev_err(reader->dev, "%s: invalid reader state", __func__);
265 		return -EINVAL;
266 	}
267 
268 	/* Turn the reader off */
269 	SET_UNIPERIF_CTRL_OPERATION_OFF(reader);
270 
271 	/* Disable interrupts */
272 	SET_UNIPERIF_ITM_BCLR(reader, GET_UNIPERIF_ITM(reader));
273 
274 	/* Update state to stopped and return */
275 	reader->state = UNIPERIF_STATE_STOPPED;
276 
277 	return 0;
278 }
279 
280 static int  uni_reader_trigger(struct snd_pcm_substream *substream,
281 			       int cmd, struct snd_soc_dai *dai)
282 {
283 	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
284 	struct uniperif *reader = priv->dai_data.uni;
285 
286 	switch (cmd) {
287 	case SNDRV_PCM_TRIGGER_START:
288 		return  uni_reader_start(reader);
289 	case SNDRV_PCM_TRIGGER_STOP:
290 		return  uni_reader_stop(reader);
291 	default:
292 		return -EINVAL;
293 	}
294 }
295 
296 static void uni_reader_shutdown(struct snd_pcm_substream *substream,
297 				struct snd_soc_dai *dai)
298 {
299 	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
300 	struct uniperif *reader = priv->dai_data.uni;
301 
302 	if (reader->state != UNIPERIF_STATE_STOPPED) {
303 		/* Stop the reader */
304 		uni_reader_stop(reader);
305 	}
306 }
307 
308 static int uni_reader_parse_dt(struct platform_device *pdev,
309 			       struct uniperif *reader)
310 {
311 	struct uniperif_info *info;
312 	struct device_node *node = pdev->dev.of_node;
313 
314 	/* Allocate memory for the info structure */
315 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
316 	if (!info)
317 		return -ENOMEM;
318 
319 	if (of_property_read_u32(node, "version", &reader->ver) ||
320 	    reader->ver == SND_ST_UNIPERIF_VERSION_UNKNOWN) {
321 		dev_err(&pdev->dev, "Unknown uniperipheral version ");
322 		return -EINVAL;
323 	}
324 
325 	/* Save the info structure */
326 	reader->info = info;
327 
328 	return 0;
329 }
330 
331 static const struct snd_soc_dai_ops uni_reader_dai_ops = {
332 		.shutdown = uni_reader_shutdown,
333 		.prepare = uni_reader_prepare,
334 		.trigger = uni_reader_trigger,
335 		.hw_params = sti_uniperiph_dai_hw_params,
336 		.set_fmt = sti_uniperiph_dai_set_fmt,
337 };
338 
339 int uni_reader_init(struct platform_device *pdev,
340 		    struct uniperif *reader)
341 {
342 	int ret = 0;
343 
344 	reader->dev = &pdev->dev;
345 	reader->state = UNIPERIF_STATE_STOPPED;
346 	reader->hw = &uni_reader_pcm_hw;
347 	reader->dai_ops = &uni_reader_dai_ops;
348 
349 	dev_err(reader->dev, "%s: enter\n", __func__);
350 	ret = uni_reader_parse_dt(pdev, reader);
351 	if (ret < 0) {
352 		dev_err(reader->dev, "Failed to parse DeviceTree");
353 		return ret;
354 	}
355 
356 	ret = devm_request_irq(&pdev->dev, reader->irq,
357 			       uni_reader_irq_handler, IRQF_SHARED,
358 			       dev_name(&pdev->dev), reader);
359 	if (ret < 0) {
360 		dev_err(&pdev->dev, "Failed to request IRQ");
361 		return -EBUSY;
362 	}
363 
364 	return 0;
365 }
366 EXPORT_SYMBOL_GPL(uni_reader_init);
367