xref: /linux/sound/soc/meson/axg-pdm.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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_irq.h>
9 #include <linux/of_platform.h>
10 #include <linux/regmap.h>
11 #include <sound/soc.h>
12 #include <sound/soc-dai.h>
13 #include <sound/pcm_params.h>
14 
15 #define PDM_CTRL			0x00
16 #define  PDM_CTRL_EN			BIT(31)
17 #define  PDM_CTRL_OUT_MODE		BIT(29)
18 #define  PDM_CTRL_BYPASS_MODE		BIT(28)
19 #define  PDM_CTRL_RST_FIFO		BIT(16)
20 #define  PDM_CTRL_CHAN_RSTN_MASK	GENMASK(15, 8)
21 #define  PDM_CTRL_CHAN_RSTN(x)		((x) << 8)
22 #define  PDM_CTRL_CHAN_EN_MASK		GENMASK(7, 0)
23 #define  PDM_CTRL_CHAN_EN(x)		((x) << 0)
24 #define PDM_HCIC_CTRL1			0x04
25 #define  PDM_FILTER_EN			BIT(31)
26 #define  PDM_HCIC_CTRL1_GAIN_SFT_MASK	GENMASK(29, 24)
27 #define  PDM_HCIC_CTRL1_GAIN_SFT(x)	((x) << 24)
28 #define  PDM_HCIC_CTRL1_GAIN_MULT_MASK	GENMASK(23, 16)
29 #define  PDM_HCIC_CTRL1_GAIN_MULT(x)	((x) << 16)
30 #define  PDM_HCIC_CTRL1_DSR_MASK	GENMASK(8, 4)
31 #define  PDM_HCIC_CTRL1_DSR(x)		((x) << 4)
32 #define  PDM_HCIC_CTRL1_STAGE_NUM_MASK	GENMASK(3, 0)
33 #define  PDM_HCIC_CTRL1_STAGE_NUM(x)	((x) << 0)
34 #define PDM_HCIC_CTRL2			0x08
35 #define PDM_F1_CTRL			0x0c
36 #define  PDM_LPF_ROUND_MODE_MASK	GENMASK(17, 16)
37 #define  PDM_LPF_ROUND_MODE(x)		((x) << 16)
38 #define  PDM_LPF_DSR_MASK		GENMASK(15, 12)
39 #define  PDM_LPF_DSR(x)			((x) << 12)
40 #define  PDM_LPF_STAGE_NUM_MASK		GENMASK(8, 0)
41 #define  PDM_LPF_STAGE_NUM(x)		((x) << 0)
42 #define  PDM_LPF_MAX_STAGE		336
43 #define  PDM_LPF_NUM			3
44 #define PDM_F2_CTRL			0x10
45 #define PDM_F3_CTRL			0x14
46 #define PDM_HPF_CTRL			0x18
47 #define  PDM_HPF_SFT_STEPS_MASK		GENMASK(20, 16)
48 #define  PDM_HPF_SFT_STEPS(x)		((x) << 16)
49 #define  PDM_HPF_OUT_FACTOR_MASK	GENMASK(15, 0)
50 #define  PDM_HPF_OUT_FACTOR(x)		((x) << 0)
51 #define PDM_CHAN_CTRL			0x1c
52 #define  PDM_CHAN_CTRL_POINTER_WIDTH	8
53 #define  PDM_CHAN_CTRL_POINTER_MAX	((1 << PDM_CHAN_CTRL_POINTER_WIDTH) - 1)
54 #define  PDM_CHAN_CTRL_NUM		4
55 #define PDM_CHAN_CTRL1			0x20
56 #define PDM_COEFF_ADDR			0x24
57 #define PDM_COEFF_DATA			0x28
58 #define PDM_CLKG_CTRL			0x2c
59 #define PDM_STS				0x30
60 
61 struct axg_pdm_lpf {
62 	unsigned int ds;
63 	unsigned int round_mode;
64 	const unsigned int *tap;
65 	unsigned int tap_num;
66 };
67 
68 struct axg_pdm_hcic {
69 	unsigned int shift;
70 	unsigned int mult;
71 	unsigned int steps;
72 	unsigned int ds;
73 };
74 
75 struct axg_pdm_hpf {
76 	unsigned int out_factor;
77 	unsigned int steps;
78 };
79 
80 struct axg_pdm_filters {
81 	struct axg_pdm_hcic hcic;
82 	struct axg_pdm_hpf hpf;
83 	struct axg_pdm_lpf lpf[PDM_LPF_NUM];
84 };
85 
86 struct axg_pdm_cfg {
87 	const struct axg_pdm_filters *filters;
88 	unsigned int sys_rate;
89 };
90 
91 struct axg_pdm {
92 	const struct axg_pdm_cfg *cfg;
93 	struct regmap *map;
94 	struct clk *dclk;
95 	struct clk *sysclk;
96 	struct clk *pclk;
97 };
98 
99 static void axg_pdm_enable(struct regmap *map)
100 {
101 	/* Reset AFIFO */
102 	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_RST_FIFO, PDM_CTRL_RST_FIFO);
103 	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_RST_FIFO, 0);
104 
105 	/* Enable PDM */
106 	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_EN, PDM_CTRL_EN);
107 }
108 
109 static void axg_pdm_disable(struct regmap *map)
110 {
111 	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_EN, 0);
112 }
113 
114 static void axg_pdm_filters_enable(struct regmap *map, bool enable)
115 {
116 	unsigned int val = enable ? PDM_FILTER_EN : 0;
117 
118 	regmap_update_bits(map, PDM_HCIC_CTRL1, PDM_FILTER_EN, val);
119 	regmap_update_bits(map, PDM_F1_CTRL, PDM_FILTER_EN, val);
120 	regmap_update_bits(map, PDM_F2_CTRL, PDM_FILTER_EN, val);
121 	regmap_update_bits(map, PDM_F3_CTRL, PDM_FILTER_EN, val);
122 	regmap_update_bits(map, PDM_HPF_CTRL, PDM_FILTER_EN, val);
123 }
124 
125 static int axg_pdm_trigger(struct snd_pcm_substream *substream, int cmd,
126 			   struct snd_soc_dai *dai)
127 {
128 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
129 
130 	switch (cmd) {
131 	case SNDRV_PCM_TRIGGER_START:
132 	case SNDRV_PCM_TRIGGER_RESUME:
133 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
134 		axg_pdm_enable(priv->map);
135 		return 0;
136 
137 	case SNDRV_PCM_TRIGGER_STOP:
138 	case SNDRV_PCM_TRIGGER_SUSPEND:
139 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
140 		axg_pdm_disable(priv->map);
141 		return 0;
142 
143 	default:
144 		return -EINVAL;
145 	}
146 }
147 
148 static unsigned int axg_pdm_get_os(struct axg_pdm *priv)
149 {
150 	const struct axg_pdm_filters *filters = priv->cfg->filters;
151 	unsigned int os = filters->hcic.ds;
152 	int i;
153 
154 	/*
155 	 * The global oversampling factor is defined by the down sampling
156 	 * factor applied by each filter (HCIC and LPFs)
157 	 */
158 
159 	for (i = 0; i < PDM_LPF_NUM; i++)
160 		os *= filters->lpf[i].ds;
161 
162 	return os;
163 }
164 
165 static int axg_pdm_set_sysclk(struct axg_pdm *priv, unsigned int os,
166 			      unsigned int rate)
167 {
168 	unsigned int sys_rate = os * 2 * rate * PDM_CHAN_CTRL_POINTER_MAX;
169 
170 	/*
171 	 * Set the default system clock rate unless it is too fast for
172 	 * for the requested sample rate. In this case, the sample pointer
173 	 * counter could overflow so set a lower system clock rate
174 	 */
175 	if (sys_rate < priv->cfg->sys_rate)
176 		return clk_set_rate(priv->sysclk, sys_rate);
177 
178 	return clk_set_rate(priv->sysclk, priv->cfg->sys_rate);
179 }
180 
181 static int axg_pdm_set_sample_pointer(struct axg_pdm *priv)
182 {
183 	unsigned int spmax, sp, val;
184 	int i;
185 
186 	/* Max sample counter value per half period of dclk */
187 	spmax = DIV_ROUND_UP_ULL((u64)clk_get_rate(priv->sysclk),
188 				 clk_get_rate(priv->dclk) * 2);
189 
190 	/* Check if sysclk is not too fast - should not happen */
191 	if (WARN_ON(spmax > PDM_CHAN_CTRL_POINTER_MAX))
192 		return -EINVAL;
193 
194 	/* Capture the data when we are at 75% of the half period */
195 	sp = spmax * 3 / 4;
196 
197 	for (i = 0, val = 0; i < PDM_CHAN_CTRL_NUM; i++)
198 		val |= sp << (PDM_CHAN_CTRL_POINTER_WIDTH * i);
199 
200 	regmap_write(priv->map, PDM_CHAN_CTRL, val);
201 	regmap_write(priv->map, PDM_CHAN_CTRL1, val);
202 
203 	return 0;
204 }
205 
206 static void axg_pdm_set_channel_mask(struct axg_pdm *priv,
207 				     unsigned int channels)
208 {
209 	unsigned int mask = GENMASK(channels - 1, 0);
210 
211 	/* Put all channel in reset */
212 	regmap_update_bits(priv->map, PDM_CTRL,
213 			   PDM_CTRL_CHAN_RSTN_MASK, 0);
214 
215 	/* Take the necessary channels out of reset and enable them */
216 	regmap_update_bits(priv->map, PDM_CTRL,
217 			   PDM_CTRL_CHAN_RSTN_MASK |
218 			   PDM_CTRL_CHAN_EN_MASK,
219 			   PDM_CTRL_CHAN_RSTN(mask) |
220 			   PDM_CTRL_CHAN_EN(mask));
221 }
222 
223 static int axg_pdm_hw_params(struct snd_pcm_substream *substream,
224 			     struct snd_pcm_hw_params *params,
225 			     struct snd_soc_dai *dai)
226 {
227 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
228 	unsigned int os = axg_pdm_get_os(priv);
229 	unsigned int rate = params_rate(params);
230 	unsigned int val;
231 	int ret;
232 
233 	switch (params_width(params)) {
234 	case 24:
235 		val = PDM_CTRL_OUT_MODE;
236 		break;
237 	case 32:
238 		val = 0;
239 		break;
240 	default:
241 		dev_err(dai->dev, "unsupported sample width\n");
242 		return -EINVAL;
243 	}
244 
245 	regmap_update_bits(priv->map, PDM_CTRL, PDM_CTRL_OUT_MODE, val);
246 
247 	ret = axg_pdm_set_sysclk(priv, os, rate);
248 	if (ret) {
249 		dev_err(dai->dev, "failed to set system clock\n");
250 		return ret;
251 	}
252 
253 	ret = clk_set_rate(priv->dclk, rate * os);
254 	if (ret) {
255 		dev_err(dai->dev, "failed to set dclk\n");
256 		return ret;
257 	}
258 
259 	ret = axg_pdm_set_sample_pointer(priv);
260 	if (ret) {
261 		dev_err(dai->dev, "invalid clock setting\n");
262 		return ret;
263 	}
264 
265 	axg_pdm_set_channel_mask(priv, params_channels(params));
266 
267 	return 0;
268 }
269 
270 static int axg_pdm_startup(struct snd_pcm_substream *substream,
271 			   struct snd_soc_dai *dai)
272 {
273 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
274 	int ret;
275 
276 	ret = clk_prepare_enable(priv->dclk);
277 	if (ret) {
278 		dev_err(dai->dev, "enabling dclk failed\n");
279 		return ret;
280 	}
281 
282 	/* Enable the filters */
283 	axg_pdm_filters_enable(priv->map, true);
284 
285 	return ret;
286 }
287 
288 static void axg_pdm_shutdown(struct snd_pcm_substream *substream,
289 			     struct snd_soc_dai *dai)
290 {
291 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
292 
293 	axg_pdm_filters_enable(priv->map, false);
294 	clk_disable_unprepare(priv->dclk);
295 }
296 
297 static const struct snd_soc_dai_ops axg_pdm_dai_ops = {
298 	.trigger	= axg_pdm_trigger,
299 	.hw_params	= axg_pdm_hw_params,
300 	.startup	= axg_pdm_startup,
301 	.shutdown	= axg_pdm_shutdown,
302 };
303 
304 static void axg_pdm_set_hcic_ctrl(struct axg_pdm *priv)
305 {
306 	const struct axg_pdm_hcic *hcic = &priv->cfg->filters->hcic;
307 	unsigned int val;
308 
309 	val = PDM_HCIC_CTRL1_STAGE_NUM(hcic->steps);
310 	val |= PDM_HCIC_CTRL1_DSR(hcic->ds);
311 	val |= PDM_HCIC_CTRL1_GAIN_MULT(hcic->mult);
312 	val |= PDM_HCIC_CTRL1_GAIN_SFT(hcic->shift);
313 
314 	regmap_update_bits(priv->map, PDM_HCIC_CTRL1,
315 			   PDM_HCIC_CTRL1_STAGE_NUM_MASK |
316 			   PDM_HCIC_CTRL1_DSR_MASK |
317 			   PDM_HCIC_CTRL1_GAIN_MULT_MASK |
318 			   PDM_HCIC_CTRL1_GAIN_SFT_MASK,
319 			   val);
320 }
321 
322 static void axg_pdm_set_lpf_ctrl(struct axg_pdm *priv, unsigned int index)
323 {
324 	const struct axg_pdm_lpf *lpf = &priv->cfg->filters->lpf[index];
325 	unsigned int offset = index * regmap_get_reg_stride(priv->map)
326 		+ PDM_F1_CTRL;
327 	unsigned int val;
328 
329 	val = PDM_LPF_STAGE_NUM(lpf->tap_num);
330 	val |= PDM_LPF_DSR(lpf->ds);
331 	val |= PDM_LPF_ROUND_MODE(lpf->round_mode);
332 
333 	regmap_update_bits(priv->map, offset,
334 			   PDM_LPF_STAGE_NUM_MASK |
335 			   PDM_LPF_DSR_MASK |
336 			   PDM_LPF_ROUND_MODE_MASK,
337 			   val);
338 }
339 
340 static void axg_pdm_set_hpf_ctrl(struct axg_pdm *priv)
341 {
342 	const struct axg_pdm_hpf *hpf = &priv->cfg->filters->hpf;
343 	unsigned int val;
344 
345 	val = PDM_HPF_OUT_FACTOR(hpf->out_factor);
346 	val |= PDM_HPF_SFT_STEPS(hpf->steps);
347 
348 	regmap_update_bits(priv->map, PDM_HPF_CTRL,
349 			   PDM_HPF_OUT_FACTOR_MASK |
350 			   PDM_HPF_SFT_STEPS_MASK,
351 			   val);
352 }
353 
354 static int axg_pdm_set_lpf_filters(struct axg_pdm *priv)
355 {
356 	const struct axg_pdm_lpf *lpf = priv->cfg->filters->lpf;
357 	unsigned int count = 0;
358 	int i, j;
359 
360 	for (i = 0; i < PDM_LPF_NUM; i++)
361 		count += lpf[i].tap_num;
362 
363 	/* Make sure the coeffs fit in the memory */
364 	if (count >= PDM_LPF_MAX_STAGE)
365 		return -EINVAL;
366 
367 	/* Set the initial APB bus register address */
368 	regmap_write(priv->map, PDM_COEFF_ADDR, 0);
369 
370 	/* Set the tap filter values of all 3 filters */
371 	for (i = 0; i < PDM_LPF_NUM; i++) {
372 		axg_pdm_set_lpf_ctrl(priv, i);
373 
374 		for (j = 0; j < lpf[i].tap_num; j++)
375 			regmap_write(priv->map, PDM_COEFF_DATA, lpf[i].tap[j]);
376 	}
377 
378 	return 0;
379 }
380 
381 static int axg_pdm_dai_probe(struct snd_soc_dai *dai)
382 {
383 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
384 	int ret;
385 
386 	ret = clk_prepare_enable(priv->pclk);
387 	if (ret) {
388 		dev_err(dai->dev, "enabling pclk failed\n");
389 		return ret;
390 	}
391 
392 	/*
393 	 * sysclk must be set and enabled as well to access the pdm registers
394 	 * Accessing the register w/o it will give a bus error.
395 	 */
396 	ret = clk_set_rate(priv->sysclk, priv->cfg->sys_rate);
397 	if (ret) {
398 		dev_err(dai->dev, "setting sysclk failed\n");
399 		goto err_pclk;
400 	}
401 
402 	ret = clk_prepare_enable(priv->sysclk);
403 	if (ret) {
404 		dev_err(dai->dev, "enabling sysclk failed\n");
405 		goto err_pclk;
406 	}
407 
408 	/* Make sure the device is initially disabled */
409 	axg_pdm_disable(priv->map);
410 
411 	/* Make sure filter bypass is disabled */
412 	regmap_update_bits(priv->map, PDM_CTRL, PDM_CTRL_BYPASS_MODE, 0);
413 
414 	/* Load filter settings */
415 	axg_pdm_set_hcic_ctrl(priv);
416 	axg_pdm_set_hpf_ctrl(priv);
417 
418 	ret = axg_pdm_set_lpf_filters(priv);
419 	if (ret) {
420 		dev_err(dai->dev, "invalid filter configuration\n");
421 		goto err_sysclk;
422 	}
423 
424 	return 0;
425 
426 err_sysclk:
427 	clk_disable_unprepare(priv->sysclk);
428 err_pclk:
429 	clk_disable_unprepare(priv->pclk);
430 	return ret;
431 }
432 
433 static int axg_pdm_dai_remove(struct snd_soc_dai *dai)
434 {
435 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
436 
437 	clk_disable_unprepare(priv->sysclk);
438 	clk_disable_unprepare(priv->pclk);
439 
440 	return 0;
441 }
442 
443 static struct snd_soc_dai_driver axg_pdm_dai_drv = {
444 	.name = "PDM",
445 	.capture = {
446 		.stream_name	= "Capture",
447 		.channels_min	= 1,
448 		.channels_max	= 8,
449 		.rates		= SNDRV_PCM_RATE_CONTINUOUS,
450 		.rate_min	= 5512,
451 		.rate_max	= 48000,
452 		.formats	= (SNDRV_PCM_FMTBIT_S24_LE |
453 				   SNDRV_PCM_FMTBIT_S32_LE),
454 	},
455 	.ops		= &axg_pdm_dai_ops,
456 	.probe		= axg_pdm_dai_probe,
457 	.remove		= axg_pdm_dai_remove,
458 };
459 
460 static const struct snd_soc_component_driver axg_pdm_component_drv = {};
461 
462 static const struct regmap_config axg_pdm_regmap_cfg = {
463 	.reg_bits	= 32,
464 	.val_bits	= 32,
465 	.reg_stride	= 4,
466 	.max_register	= PDM_STS,
467 };
468 
469 static const unsigned int lpf1_default_tap[] = {
470 	0x000014, 0xffffb2, 0xfffed9, 0xfffdce, 0xfffd45,
471 	0xfffe32, 0x000147, 0x000645, 0x000b86, 0x000e21,
472 	0x000ae3, 0x000000, 0xffeece, 0xffdca8, 0xffd212,
473 	0xffd7d1, 0xfff2a7, 0x001f4c, 0x0050c2, 0x0072aa,
474 	0x006ff1, 0x003c32, 0xffdc4e, 0xff6a18, 0xff0fef,
475 	0xfefbaf, 0xff4c40, 0x000000, 0x00ebc8, 0x01c077,
476 	0x02209e, 0x01c1a4, 0x008e60, 0xfebe52, 0xfcd690,
477 	0xfb8fa5, 0xfba498, 0xfd9812, 0x0181ce, 0x06f5f3,
478 	0x0d112f, 0x12a958, 0x169686, 0x18000e, 0x169686,
479 	0x12a958, 0x0d112f, 0x06f5f3, 0x0181ce, 0xfd9812,
480 	0xfba498, 0xfb8fa5, 0xfcd690, 0xfebe52, 0x008e60,
481 	0x01c1a4, 0x02209e, 0x01c077, 0x00ebc8, 0x000000,
482 	0xff4c40, 0xfefbaf, 0xff0fef, 0xff6a18, 0xffdc4e,
483 	0x003c32, 0x006ff1, 0x0072aa, 0x0050c2, 0x001f4c,
484 	0xfff2a7, 0xffd7d1, 0xffd212, 0xffdca8, 0xffeece,
485 	0x000000, 0x000ae3, 0x000e21, 0x000b86, 0x000645,
486 	0x000147, 0xfffe32, 0xfffd45, 0xfffdce, 0xfffed9,
487 	0xffffb2, 0x000014,
488 };
489 
490 static const unsigned int lpf2_default_tap[] = {
491 	0x00050a, 0xfff004, 0x0002c1, 0x003c12, 0xffa818,
492 	0xffc87d, 0x010aef, 0xff5223, 0xfebd93, 0x028f41,
493 	0xff5c0e, 0xfc63f8, 0x055f81, 0x000000, 0xf478a0,
494 	0x11c5e3, 0x2ea74d, 0x11c5e3, 0xf478a0, 0x000000,
495 	0x055f81, 0xfc63f8, 0xff5c0e, 0x028f41, 0xfebd93,
496 	0xff5223, 0x010aef, 0xffc87d, 0xffa818, 0x003c12,
497 	0x0002c1, 0xfff004, 0x00050a,
498 };
499 
500 static const unsigned int lpf3_default_tap[] = {
501 	0x000000, 0x000081, 0x000000, 0xfffedb, 0x000000,
502 	0x00022d, 0x000000, 0xfffc46, 0x000000, 0x0005f7,
503 	0x000000, 0xfff6eb, 0x000000, 0x000d4e, 0x000000,
504 	0xffed1e, 0x000000, 0x001a1c, 0x000000, 0xffdcb0,
505 	0x000000, 0x002ede, 0x000000, 0xffc2d1, 0x000000,
506 	0x004ebe, 0x000000, 0xff9beb, 0x000000, 0x007dd7,
507 	0x000000, 0xff633a, 0x000000, 0x00c1d2, 0x000000,
508 	0xff11d5, 0x000000, 0x012368, 0x000000, 0xfe9c45,
509 	0x000000, 0x01b252, 0x000000, 0xfdebf6, 0x000000,
510 	0x0290b8, 0x000000, 0xfcca0d, 0x000000, 0x041d7c,
511 	0x000000, 0xfa8152, 0x000000, 0x07e9c6, 0x000000,
512 	0xf28fb5, 0x000000, 0x28b216, 0x3fffde, 0x28b216,
513 	0x000000, 0xf28fb5, 0x000000, 0x07e9c6, 0x000000,
514 	0xfa8152, 0x000000, 0x041d7c, 0x000000, 0xfcca0d,
515 	0x000000, 0x0290b8, 0x000000, 0xfdebf6, 0x000000,
516 	0x01b252, 0x000000, 0xfe9c45, 0x000000, 0x012368,
517 	0x000000, 0xff11d5, 0x000000, 0x00c1d2, 0x000000,
518 	0xff633a, 0x000000, 0x007dd7, 0x000000, 0xff9beb,
519 	0x000000, 0x004ebe, 0x000000, 0xffc2d1, 0x000000,
520 	0x002ede, 0x000000, 0xffdcb0, 0x000000, 0x001a1c,
521 	0x000000, 0xffed1e, 0x000000, 0x000d4e, 0x000000,
522 	0xfff6eb, 0x000000, 0x0005f7, 0x000000, 0xfffc46,
523 	0x000000, 0x00022d, 0x000000, 0xfffedb, 0x000000,
524 	0x000081, 0x000000,
525 };
526 
527 /*
528  * These values are sane defaults for the axg platform:
529  * - OS = 64
530  * - Latency = 38700 (?)
531  *
532  * TODO: There is a lot of different HCIC, LPFs and HPF configurations possible.
533  *       the configuration may depend on the dmic used by the platform, the
534  *       expected tradeoff between latency and quality, etc ... If/When other
535  *       settings are required, we should add a fw interface to this driver to
536  *       load new filter settings.
537  */
538 static const struct axg_pdm_filters axg_default_filters = {
539 	.hcic = {
540 		.shift = 0x15,
541 		.mult = 0x80,
542 		.steps = 7,
543 		.ds = 8,
544 	},
545 	.hpf = {
546 		.out_factor = 0x8000,
547 		.steps = 13,
548 	},
549 	.lpf = {
550 		[0] = {
551 			.ds = 2,
552 			.round_mode = 1,
553 			.tap = lpf1_default_tap,
554 			.tap_num = ARRAY_SIZE(lpf1_default_tap),
555 		},
556 		[1] = {
557 			.ds = 2,
558 			.round_mode = 0,
559 			.tap = lpf2_default_tap,
560 			.tap_num = ARRAY_SIZE(lpf2_default_tap),
561 		},
562 		[2] = {
563 			.ds = 2,
564 			.round_mode = 1,
565 			.tap = lpf3_default_tap,
566 			.tap_num = ARRAY_SIZE(lpf3_default_tap)
567 		},
568 	},
569 };
570 
571 static const struct axg_pdm_cfg axg_pdm_config = {
572 	.filters = &axg_default_filters,
573 	.sys_rate = 250000000,
574 };
575 
576 static const struct of_device_id axg_pdm_of_match[] = {
577 	{
578 		.compatible = "amlogic,axg-pdm",
579 		.data = &axg_pdm_config,
580 	}, {}
581 };
582 MODULE_DEVICE_TABLE(of, axg_pdm_of_match);
583 
584 static int axg_pdm_probe(struct platform_device *pdev)
585 {
586 	struct device *dev = &pdev->dev;
587 	struct axg_pdm *priv;
588 	struct resource *res;
589 	void __iomem *regs;
590 	int ret;
591 
592 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
593 	if (!priv)
594 		return -ENOMEM;
595 	platform_set_drvdata(pdev, priv);
596 
597 	priv->cfg = of_device_get_match_data(dev);
598 	if (!priv->cfg) {
599 		dev_err(dev, "failed to match device\n");
600 		return -ENODEV;
601 	}
602 
603 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
604 	regs = devm_ioremap_resource(dev, res);
605 	if (IS_ERR(regs))
606 		return PTR_ERR(regs);
607 
608 	priv->map = devm_regmap_init_mmio(dev, regs, &axg_pdm_regmap_cfg);
609 	if (IS_ERR(priv->map)) {
610 		dev_err(dev, "failed to init regmap: %ld\n",
611 			PTR_ERR(priv->map));
612 		return PTR_ERR(priv->map);
613 	}
614 
615 	priv->pclk = devm_clk_get(dev, "pclk");
616 	if (IS_ERR(priv->pclk)) {
617 		ret = PTR_ERR(priv->pclk);
618 		if (ret != -EPROBE_DEFER)
619 			dev_err(dev, "failed to get pclk: %d\n", ret);
620 		return ret;
621 	}
622 
623 	priv->dclk = devm_clk_get(dev, "dclk");
624 	if (IS_ERR(priv->dclk)) {
625 		ret = PTR_ERR(priv->dclk);
626 		if (ret != -EPROBE_DEFER)
627 			dev_err(dev, "failed to get dclk: %d\n", ret);
628 		return ret;
629 	}
630 
631 	priv->sysclk = devm_clk_get(dev, "sysclk");
632 	if (IS_ERR(priv->sysclk)) {
633 		ret = PTR_ERR(priv->sysclk);
634 		if (ret != -EPROBE_DEFER)
635 			dev_err(dev, "failed to get dclk: %d\n", ret);
636 		return ret;
637 	}
638 
639 	return devm_snd_soc_register_component(dev, &axg_pdm_component_drv,
640 					       &axg_pdm_dai_drv, 1);
641 }
642 
643 static struct platform_driver axg_pdm_pdrv = {
644 	.probe = axg_pdm_probe,
645 	.driver = {
646 		.name = "axg-pdm",
647 		.of_match_table = axg_pdm_of_match,
648 	},
649 };
650 module_platform_driver(axg_pdm_pdrv);
651 
652 MODULE_DESCRIPTION("Amlogic AXG PDM Input driver");
653 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
654 MODULE_LICENSE("GPL v2");
655