1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
2 //
3 // Copyright (c) 2018 BayLibre, SAS.
4 // Author: Jerome Brunet <jbrunet@baylibre.com>
5 
6 #include <linux/clk.h>
7 #include <linux/module.h>
8 #include <linux/of_platform.h>
9 #include <sound/pcm_params.h>
10 #include <sound/soc.h>
11 #include <sound/soc-dai.h>
12 
13 #include "axg-tdm.h"
14 
15 enum {
16 	TDM_IFACE_PAD,
17 	TDM_IFACE_LOOPBACK,
18 };
19 
20 static unsigned int axg_tdm_slots_total(u32 *mask)
21 {
22 	unsigned int slots = 0;
23 	int i;
24 
25 	if (!mask)
26 		return 0;
27 
28 	/* Count the total number of slots provided by all 4 lanes */
29 	for (i = 0; i < AXG_TDM_NUM_LANES; i++)
30 		slots += hweight32(mask[i]);
31 
32 	return slots;
33 }
34 
35 int axg_tdm_set_tdm_slots(struct snd_soc_dai *dai, u32 *tx_mask,
36 			  u32 *rx_mask, unsigned int slots,
37 			  unsigned int slot_width)
38 {
39 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
40 	struct axg_tdm_stream *tx = (struct axg_tdm_stream *)
41 		dai->playback_dma_data;
42 	struct axg_tdm_stream *rx = (struct axg_tdm_stream *)
43 		dai->capture_dma_data;
44 	unsigned int tx_slots, rx_slots;
45 	unsigned int fmt = 0;
46 
47 	tx_slots = axg_tdm_slots_total(tx_mask);
48 	rx_slots = axg_tdm_slots_total(rx_mask);
49 
50 	/* We should at least have a slot for a valid interface */
51 	if (!tx_slots && !rx_slots) {
52 		dev_err(dai->dev, "interface has no slot\n");
53 		return -EINVAL;
54 	}
55 
56 	iface->slots = slots;
57 
58 	switch (slot_width) {
59 	case 0:
60 		slot_width = 32;
61 		/* Fall-through */
62 	case 32:
63 		fmt |= SNDRV_PCM_FMTBIT_S32_LE;
64 		/* Fall-through */
65 	case 24:
66 		fmt |= SNDRV_PCM_FMTBIT_S24_LE;
67 		fmt |= SNDRV_PCM_FMTBIT_S20_LE;
68 		/* Fall-through */
69 	case 16:
70 		fmt |= SNDRV_PCM_FMTBIT_S16_LE;
71 		/* Fall-through */
72 	case 8:
73 		fmt |= SNDRV_PCM_FMTBIT_S8;
74 		break;
75 	default:
76 		dev_err(dai->dev, "unsupported slot width: %d\n", slot_width);
77 		return -EINVAL;
78 	}
79 
80 	iface->slot_width = slot_width;
81 
82 	/* Amend the dai driver and let dpcm merge do its job */
83 	if (tx) {
84 		tx->mask = tx_mask;
85 		dai->driver->playback.channels_max = tx_slots;
86 		dai->driver->playback.formats = fmt;
87 	}
88 
89 	if (rx) {
90 		rx->mask = rx_mask;
91 		dai->driver->capture.channels_max = rx_slots;
92 		dai->driver->capture.formats = fmt;
93 	}
94 
95 	return 0;
96 }
97 EXPORT_SYMBOL_GPL(axg_tdm_set_tdm_slots);
98 
99 static int axg_tdm_iface_set_sysclk(struct snd_soc_dai *dai, int clk_id,
100 				    unsigned int freq, int dir)
101 {
102 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
103 	int ret = -ENOTSUPP;
104 
105 	if (dir == SND_SOC_CLOCK_OUT && clk_id == 0) {
106 		if (!iface->mclk) {
107 			dev_warn(dai->dev, "master clock not provided\n");
108 		} else {
109 			ret = clk_set_rate(iface->mclk, freq);
110 			if (!ret)
111 				iface->mclk_rate = freq;
112 		}
113 	}
114 
115 	return ret;
116 }
117 
118 static int axg_tdm_iface_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
119 {
120 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
121 
122 	/* These modes are not supported */
123 	if (fmt & (SND_SOC_DAIFMT_CBS_CFM | SND_SOC_DAIFMT_CBM_CFS)) {
124 		dev_err(dai->dev, "only CBS_CFS and CBM_CFM are supported\n");
125 		return -EINVAL;
126 	}
127 
128 	/* If the TDM interface is the clock master, it requires mclk */
129 	if (!iface->mclk && (fmt & SND_SOC_DAIFMT_CBS_CFS)) {
130 		dev_err(dai->dev, "cpu clock master: mclk missing\n");
131 		return -ENODEV;
132 	}
133 
134 	iface->fmt = fmt;
135 	return 0;
136 }
137 
138 static int axg_tdm_iface_startup(struct snd_pcm_substream *substream,
139 				 struct snd_soc_dai *dai)
140 {
141 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
142 	struct axg_tdm_stream *ts =
143 		snd_soc_dai_get_dma_data(dai, substream);
144 	int ret;
145 
146 	if (!axg_tdm_slots_total(ts->mask)) {
147 		dev_err(dai->dev, "interface has not slots\n");
148 		return -EINVAL;
149 	}
150 
151 	/* Apply component wide rate symmetry */
152 	if (dai->component->active) {
153 		ret = snd_pcm_hw_constraint_single(substream->runtime,
154 						   SNDRV_PCM_HW_PARAM_RATE,
155 						   iface->rate);
156 		if (ret < 0) {
157 			dev_err(dai->dev,
158 				"can't set iface rate constraint\n");
159 			return ret;
160 		}
161 	}
162 
163 	return 0;
164 }
165 
166 static int axg_tdm_iface_set_stream(struct snd_pcm_substream *substream,
167 				    struct snd_pcm_hw_params *params,
168 				    struct snd_soc_dai *dai)
169 {
170 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
171 	struct axg_tdm_stream *ts = snd_soc_dai_get_dma_data(dai, substream);
172 	unsigned int channels = params_channels(params);
173 	unsigned int width = params_width(params);
174 
175 	/* Save rate and sample_bits for component symmetry */
176 	iface->rate = params_rate(params);
177 
178 	/* Make sure this interface can cope with the stream */
179 	if (axg_tdm_slots_total(ts->mask) < channels) {
180 		dev_err(dai->dev, "not enough slots for channels\n");
181 		return -EINVAL;
182 	}
183 
184 	if (iface->slot_width < width) {
185 		dev_err(dai->dev, "incompatible slots width for stream\n");
186 		return -EINVAL;
187 	}
188 
189 	/* Save the parameter for tdmout/tdmin widgets */
190 	ts->physical_width = params_physical_width(params);
191 	ts->width = params_width(params);
192 	ts->channels = params_channels(params);
193 
194 	return 0;
195 }
196 
197 static int axg_tdm_iface_set_lrclk(struct snd_soc_dai *dai,
198 				   struct snd_pcm_hw_params *params)
199 {
200 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
201 	unsigned int ratio_num;
202 	int ret;
203 
204 	ret = clk_set_rate(iface->lrclk, params_rate(params));
205 	if (ret) {
206 		dev_err(dai->dev, "setting sample clock failed: %d\n", ret);
207 		return ret;
208 	}
209 
210 	switch (iface->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
211 	case SND_SOC_DAIFMT_I2S:
212 	case SND_SOC_DAIFMT_LEFT_J:
213 	case SND_SOC_DAIFMT_RIGHT_J:
214 		/* 50% duty cycle ratio */
215 		ratio_num = 1;
216 		break;
217 
218 	case SND_SOC_DAIFMT_DSP_A:
219 	case SND_SOC_DAIFMT_DSP_B:
220 		/*
221 		 * A zero duty cycle ratio will result in setting the mininum
222 		 * ratio possible which, for this clock, is 1 cycle of the
223 		 * parent bclk clock high and the rest low, This is exactly
224 		 * what we want here.
225 		 */
226 		ratio_num = 0;
227 		break;
228 
229 	default:
230 		return -EINVAL;
231 	}
232 
233 	ret = clk_set_duty_cycle(iface->lrclk, ratio_num, 2);
234 	if (ret) {
235 		dev_err(dai->dev,
236 			"setting sample clock duty cycle failed: %d\n", ret);
237 		return ret;
238 	}
239 
240 	/* Set sample clock inversion */
241 	ret = clk_set_phase(iface->lrclk,
242 			    axg_tdm_lrclk_invert(iface->fmt) ? 180 : 0);
243 	if (ret) {
244 		dev_err(dai->dev,
245 			"setting sample clock phase failed: %d\n", ret);
246 		return ret;
247 	}
248 
249 	return 0;
250 }
251 
252 static int axg_tdm_iface_set_sclk(struct snd_soc_dai *dai,
253 				  struct snd_pcm_hw_params *params)
254 {
255 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
256 	unsigned long srate;
257 	int ret;
258 
259 	srate = iface->slots * iface->slot_width * params_rate(params);
260 
261 	if (!iface->mclk_rate) {
262 		/* If no specific mclk is requested, default to bit clock * 4 */
263 		clk_set_rate(iface->mclk, 4 * srate);
264 	} else {
265 		/* Check if we can actually get the bit clock from mclk */
266 		if (iface->mclk_rate % srate) {
267 			dev_err(dai->dev,
268 				"can't derive sclk %lu from mclk %lu\n",
269 				srate, iface->mclk_rate);
270 			return -EINVAL;
271 		}
272 	}
273 
274 	ret = clk_set_rate(iface->sclk, srate);
275 	if (ret) {
276 		dev_err(dai->dev, "setting bit clock failed: %d\n", ret);
277 		return ret;
278 	}
279 
280 	/* Set the bit clock inversion */
281 	ret = clk_set_phase(iface->sclk,
282 			    axg_tdm_sclk_invert(iface->fmt) ? 0 : 180);
283 	if (ret) {
284 		dev_err(dai->dev, "setting bit clock phase failed: %d\n", ret);
285 		return ret;
286 	}
287 
288 	return ret;
289 }
290 
291 static int axg_tdm_iface_hw_params(struct snd_pcm_substream *substream,
292 				   struct snd_pcm_hw_params *params,
293 				   struct snd_soc_dai *dai)
294 {
295 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
296 	int ret;
297 
298 	switch (iface->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
299 	case SND_SOC_DAIFMT_I2S:
300 	case SND_SOC_DAIFMT_LEFT_J:
301 	case SND_SOC_DAIFMT_RIGHT_J:
302 		if (iface->slots > 2) {
303 			dev_err(dai->dev, "bad slot number for format: %d\n",
304 				iface->slots);
305 			return -EINVAL;
306 		}
307 		break;
308 
309 	case SND_SOC_DAI_FORMAT_DSP_A:
310 	case SND_SOC_DAI_FORMAT_DSP_B:
311 		break;
312 
313 	default:
314 		dev_err(dai->dev, "unsupported dai format\n");
315 		return -EINVAL;
316 	}
317 
318 	ret = axg_tdm_iface_set_stream(substream, params, dai);
319 	if (ret)
320 		return ret;
321 
322 	if (iface->fmt & SND_SOC_DAIFMT_CBS_CFS) {
323 		ret = axg_tdm_iface_set_sclk(dai, params);
324 		if (ret)
325 			return ret;
326 
327 		ret = axg_tdm_iface_set_lrclk(dai, params);
328 		if (ret)
329 			return ret;
330 	}
331 
332 	return 0;
333 }
334 
335 static int axg_tdm_iface_hw_free(struct snd_pcm_substream *substream,
336 				 struct snd_soc_dai *dai)
337 {
338 	struct axg_tdm_stream *ts = snd_soc_dai_get_dma_data(dai, substream);
339 
340 	/* Stop all attached formatters */
341 	axg_tdm_stream_stop(ts);
342 
343 	return 0;
344 }
345 
346 static int axg_tdm_iface_prepare(struct snd_pcm_substream *substream,
347 				 struct snd_soc_dai *dai)
348 {
349 	struct axg_tdm_stream *ts = snd_soc_dai_get_dma_data(dai, substream);
350 
351 	/* Force all attached formatters to update */
352 	return axg_tdm_stream_reset(ts);
353 }
354 
355 static int axg_tdm_iface_remove_dai(struct snd_soc_dai *dai)
356 {
357 	if (dai->capture_dma_data)
358 		axg_tdm_stream_free(dai->capture_dma_data);
359 
360 	if (dai->playback_dma_data)
361 		axg_tdm_stream_free(dai->playback_dma_data);
362 
363 	return 0;
364 }
365 
366 static int axg_tdm_iface_probe_dai(struct snd_soc_dai *dai)
367 {
368 	struct axg_tdm_iface *iface = snd_soc_dai_get_drvdata(dai);
369 
370 	if (dai->capture_widget) {
371 		dai->capture_dma_data = axg_tdm_stream_alloc(iface);
372 		if (!dai->capture_dma_data)
373 			return -ENOMEM;
374 	}
375 
376 	if (dai->playback_widget) {
377 		dai->playback_dma_data = axg_tdm_stream_alloc(iface);
378 		if (!dai->playback_dma_data) {
379 			axg_tdm_iface_remove_dai(dai);
380 			return -ENOMEM;
381 		}
382 	}
383 
384 	return 0;
385 }
386 
387 static const struct snd_soc_dai_ops axg_tdm_iface_ops = {
388 	.set_sysclk	= axg_tdm_iface_set_sysclk,
389 	.set_fmt	= axg_tdm_iface_set_fmt,
390 	.startup	= axg_tdm_iface_startup,
391 	.hw_params	= axg_tdm_iface_hw_params,
392 	.prepare	= axg_tdm_iface_prepare,
393 	.hw_free	= axg_tdm_iface_hw_free,
394 };
395 
396 /* TDM Backend DAIs */
397 static const struct snd_soc_dai_driver axg_tdm_iface_dai_drv[] = {
398 	[TDM_IFACE_PAD] = {
399 		.name = "TDM Pad",
400 		.playback = {
401 			.stream_name	= "Playback",
402 			.channels_min	= 1,
403 			.channels_max	= AXG_TDM_CHANNEL_MAX,
404 			.rates		= AXG_TDM_RATES,
405 			.formats	= AXG_TDM_FORMATS,
406 		},
407 		.capture = {
408 			.stream_name	= "Capture",
409 			.channels_min	= 1,
410 			.channels_max	= AXG_TDM_CHANNEL_MAX,
411 			.rates		= AXG_TDM_RATES,
412 			.formats	= AXG_TDM_FORMATS,
413 		},
414 		.id = TDM_IFACE_PAD,
415 		.ops = &axg_tdm_iface_ops,
416 		.probe = axg_tdm_iface_probe_dai,
417 		.remove = axg_tdm_iface_remove_dai,
418 	},
419 	[TDM_IFACE_LOOPBACK] = {
420 		.name = "TDM Loopback",
421 		.capture = {
422 			.stream_name	= "Loopback",
423 			.channels_min	= 1,
424 			.channels_max	= AXG_TDM_CHANNEL_MAX,
425 			.rates		= AXG_TDM_RATES,
426 			.formats	= AXG_TDM_FORMATS,
427 		},
428 		.id = TDM_IFACE_LOOPBACK,
429 		.ops = &axg_tdm_iface_ops,
430 		.probe = axg_tdm_iface_probe_dai,
431 		.remove = axg_tdm_iface_remove_dai,
432 	},
433 };
434 
435 static int axg_tdm_iface_set_bias_level(struct snd_soc_component *component,
436 					enum snd_soc_bias_level level)
437 {
438 	struct axg_tdm_iface *iface = snd_soc_component_get_drvdata(component);
439 	enum snd_soc_bias_level now =
440 		snd_soc_component_get_bias_level(component);
441 	int ret = 0;
442 
443 	switch (level) {
444 	case SND_SOC_BIAS_PREPARE:
445 		if (now == SND_SOC_BIAS_STANDBY)
446 			ret = clk_prepare_enable(iface->mclk);
447 		break;
448 
449 	case SND_SOC_BIAS_STANDBY:
450 		if (now == SND_SOC_BIAS_PREPARE)
451 			clk_disable_unprepare(iface->mclk);
452 		break;
453 
454 	case SND_SOC_BIAS_OFF:
455 	case SND_SOC_BIAS_ON:
456 		break;
457 	}
458 
459 	return ret;
460 }
461 
462 static const struct snd_soc_component_driver axg_tdm_iface_component_drv = {
463 	.set_bias_level	= axg_tdm_iface_set_bias_level,
464 };
465 
466 static const struct of_device_id axg_tdm_iface_of_match[] = {
467 	{ .compatible = "amlogic,axg-tdm-iface", },
468 	{}
469 };
470 MODULE_DEVICE_TABLE(of, axg_tdm_iface_of_match);
471 
472 static int axg_tdm_iface_probe(struct platform_device *pdev)
473 {
474 	struct device *dev = &pdev->dev;
475 	struct snd_soc_dai_driver *dai_drv;
476 	struct axg_tdm_iface *iface;
477 	int ret, i;
478 
479 	iface = devm_kzalloc(dev, sizeof(*iface), GFP_KERNEL);
480 	if (!iface)
481 		return -ENOMEM;
482 	platform_set_drvdata(pdev, iface);
483 
484 	/*
485 	 * Duplicate dai driver: depending on the slot masks configuration
486 	 * We'll change the number of channel provided by DAI stream, so dpcm
487 	 * channel merge can be done properly
488 	 */
489 	dai_drv = devm_kcalloc(dev, ARRAY_SIZE(axg_tdm_iface_dai_drv),
490 			       sizeof(*dai_drv), GFP_KERNEL);
491 	if (!dai_drv)
492 		return -ENOMEM;
493 
494 	for (i = 0; i < ARRAY_SIZE(axg_tdm_iface_dai_drv); i++)
495 		memcpy(&dai_drv[i], &axg_tdm_iface_dai_drv[i],
496 		       sizeof(*dai_drv));
497 
498 	/* Bit clock provided on the pad */
499 	iface->sclk = devm_clk_get(dev, "sclk");
500 	if (IS_ERR(iface->sclk)) {
501 		ret = PTR_ERR(iface->sclk);
502 		if (ret != -EPROBE_DEFER)
503 			dev_err(dev, "failed to get sclk: %d\n", ret);
504 		return ret;
505 	}
506 
507 	/* Sample clock provided on the pad */
508 	iface->lrclk = devm_clk_get(dev, "lrclk");
509 	if (IS_ERR(iface->lrclk)) {
510 		ret = PTR_ERR(iface->lrclk);
511 		if (ret != -EPROBE_DEFER)
512 			dev_err(dev, "failed to get lrclk: %d\n", ret);
513 		return ret;
514 	}
515 
516 	/*
517 	 * mclk maybe be missing when the cpu dai is in slave mode and
518 	 * the codec does not require it to provide a master clock.
519 	 * At this point, ignore the error if mclk is missing. We'll
520 	 * throw an error if the cpu dai is master and mclk is missing
521 	 */
522 	iface->mclk = devm_clk_get(dev, "mclk");
523 	if (IS_ERR(iface->mclk)) {
524 		ret = PTR_ERR(iface->mclk);
525 		if (ret == -ENOENT) {
526 			iface->mclk = NULL;
527 		} else {
528 			if (ret != -EPROBE_DEFER)
529 				dev_err(dev, "failed to get mclk: %d\n", ret);
530 			return ret;
531 		}
532 	}
533 
534 	return devm_snd_soc_register_component(dev,
535 					&axg_tdm_iface_component_drv, dai_drv,
536 					ARRAY_SIZE(axg_tdm_iface_dai_drv));
537 }
538 
539 static struct platform_driver axg_tdm_iface_pdrv = {
540 	.probe = axg_tdm_iface_probe,
541 	.driver = {
542 		.name = "axg-tdm-iface",
543 		.of_match_table = axg_tdm_iface_of_match,
544 	},
545 };
546 module_platform_driver(axg_tdm_iface_pdrv);
547 
548 MODULE_DESCRIPTION("Amlogic AXG TDM interface driver");
549 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
550 MODULE_LICENSE("GPL v2");
551