xref: /openbmc/linux/sound/soc/meson/axg-pdm.c (revision 9470114d)
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 	 * 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 void axg_pdm_set_hcic_ctrl(struct axg_pdm *priv)
298 {
299 	const struct axg_pdm_hcic *hcic = &priv->cfg->filters->hcic;
300 	unsigned int val;
301 
302 	val = PDM_HCIC_CTRL1_STAGE_NUM(hcic->steps);
303 	val |= PDM_HCIC_CTRL1_DSR(hcic->ds);
304 	val |= PDM_HCIC_CTRL1_GAIN_MULT(hcic->mult);
305 	val |= PDM_HCIC_CTRL1_GAIN_SFT(hcic->shift);
306 
307 	regmap_update_bits(priv->map, PDM_HCIC_CTRL1,
308 			   PDM_HCIC_CTRL1_STAGE_NUM_MASK |
309 			   PDM_HCIC_CTRL1_DSR_MASK |
310 			   PDM_HCIC_CTRL1_GAIN_MULT_MASK |
311 			   PDM_HCIC_CTRL1_GAIN_SFT_MASK,
312 			   val);
313 }
314 
315 static void axg_pdm_set_lpf_ctrl(struct axg_pdm *priv, unsigned int index)
316 {
317 	const struct axg_pdm_lpf *lpf = &priv->cfg->filters->lpf[index];
318 	unsigned int offset = index * regmap_get_reg_stride(priv->map)
319 		+ PDM_F1_CTRL;
320 	unsigned int val;
321 
322 	val = PDM_LPF_STAGE_NUM(lpf->tap_num);
323 	val |= PDM_LPF_DSR(lpf->ds);
324 	val |= PDM_LPF_ROUND_MODE(lpf->round_mode);
325 
326 	regmap_update_bits(priv->map, offset,
327 			   PDM_LPF_STAGE_NUM_MASK |
328 			   PDM_LPF_DSR_MASK |
329 			   PDM_LPF_ROUND_MODE_MASK,
330 			   val);
331 }
332 
333 static void axg_pdm_set_hpf_ctrl(struct axg_pdm *priv)
334 {
335 	const struct axg_pdm_hpf *hpf = &priv->cfg->filters->hpf;
336 	unsigned int val;
337 
338 	val = PDM_HPF_OUT_FACTOR(hpf->out_factor);
339 	val |= PDM_HPF_SFT_STEPS(hpf->steps);
340 
341 	regmap_update_bits(priv->map, PDM_HPF_CTRL,
342 			   PDM_HPF_OUT_FACTOR_MASK |
343 			   PDM_HPF_SFT_STEPS_MASK,
344 			   val);
345 }
346 
347 static int axg_pdm_set_lpf_filters(struct axg_pdm *priv)
348 {
349 	const struct axg_pdm_lpf *lpf = priv->cfg->filters->lpf;
350 	unsigned int count = 0;
351 	int i, j;
352 
353 	for (i = 0; i < PDM_LPF_NUM; i++)
354 		count += lpf[i].tap_num;
355 
356 	/* Make sure the coeffs fit in the memory */
357 	if (count >= PDM_LPF_MAX_STAGE)
358 		return -EINVAL;
359 
360 	/* Set the initial APB bus register address */
361 	regmap_write(priv->map, PDM_COEFF_ADDR, 0);
362 
363 	/* Set the tap filter values of all 3 filters */
364 	for (i = 0; i < PDM_LPF_NUM; i++) {
365 		axg_pdm_set_lpf_ctrl(priv, i);
366 
367 		for (j = 0; j < lpf[i].tap_num; j++)
368 			regmap_write(priv->map, PDM_COEFF_DATA, lpf[i].tap[j]);
369 	}
370 
371 	return 0;
372 }
373 
374 static int axg_pdm_dai_probe(struct snd_soc_dai *dai)
375 {
376 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
377 	int ret;
378 
379 	ret = clk_prepare_enable(priv->pclk);
380 	if (ret) {
381 		dev_err(dai->dev, "enabling pclk failed\n");
382 		return ret;
383 	}
384 
385 	/*
386 	 * sysclk must be set and enabled as well to access the pdm registers
387 	 * Accessing the register w/o it will give a bus error.
388 	 */
389 	ret = clk_set_rate(priv->sysclk, priv->cfg->sys_rate);
390 	if (ret) {
391 		dev_err(dai->dev, "setting sysclk failed\n");
392 		goto err_pclk;
393 	}
394 
395 	ret = clk_prepare_enable(priv->sysclk);
396 	if (ret) {
397 		dev_err(dai->dev, "enabling sysclk failed\n");
398 		goto err_pclk;
399 	}
400 
401 	/* Make sure the device is initially disabled */
402 	axg_pdm_disable(priv->map);
403 
404 	/* Make sure filter bypass is disabled */
405 	regmap_update_bits(priv->map, PDM_CTRL, PDM_CTRL_BYPASS_MODE, 0);
406 
407 	/* Load filter settings */
408 	axg_pdm_set_hcic_ctrl(priv);
409 	axg_pdm_set_hpf_ctrl(priv);
410 
411 	ret = axg_pdm_set_lpf_filters(priv);
412 	if (ret) {
413 		dev_err(dai->dev, "invalid filter configuration\n");
414 		goto err_sysclk;
415 	}
416 
417 	return 0;
418 
419 err_sysclk:
420 	clk_disable_unprepare(priv->sysclk);
421 err_pclk:
422 	clk_disable_unprepare(priv->pclk);
423 	return ret;
424 }
425 
426 static int axg_pdm_dai_remove(struct snd_soc_dai *dai)
427 {
428 	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
429 
430 	clk_disable_unprepare(priv->sysclk);
431 	clk_disable_unprepare(priv->pclk);
432 
433 	return 0;
434 }
435 
436 static const struct snd_soc_dai_ops axg_pdm_dai_ops = {
437 	.probe		= axg_pdm_dai_probe,
438 	.remove		= axg_pdm_dai_remove,
439 	.trigger	= axg_pdm_trigger,
440 	.hw_params	= axg_pdm_hw_params,
441 	.startup	= axg_pdm_startup,
442 	.shutdown	= axg_pdm_shutdown,
443 };
444 
445 static struct snd_soc_dai_driver axg_pdm_dai_drv = {
446 	.name = "PDM",
447 	.capture = {
448 		.stream_name	= "Capture",
449 		.channels_min	= 1,
450 		.channels_max	= 8,
451 		.rates		= SNDRV_PCM_RATE_CONTINUOUS,
452 		.rate_min	= 5512,
453 		.rate_max	= 48000,
454 		.formats	= (SNDRV_PCM_FMTBIT_S24_LE |
455 				   SNDRV_PCM_FMTBIT_S32_LE),
456 	},
457 	.ops		= &axg_pdm_dai_ops,
458 };
459 
460 static const struct snd_soc_component_driver axg_pdm_component_drv = {
461 	.legacy_dai_naming = 1,
462 };
463 
464 static const struct regmap_config axg_pdm_regmap_cfg = {
465 	.reg_bits	= 32,
466 	.val_bits	= 32,
467 	.reg_stride	= 4,
468 	.max_register	= PDM_STS,
469 };
470 
471 static const unsigned int lpf1_default_tap[] = {
472 	0x000014, 0xffffb2, 0xfffed9, 0xfffdce, 0xfffd45,
473 	0xfffe32, 0x000147, 0x000645, 0x000b86, 0x000e21,
474 	0x000ae3, 0x000000, 0xffeece, 0xffdca8, 0xffd212,
475 	0xffd7d1, 0xfff2a7, 0x001f4c, 0x0050c2, 0x0072aa,
476 	0x006ff1, 0x003c32, 0xffdc4e, 0xff6a18, 0xff0fef,
477 	0xfefbaf, 0xff4c40, 0x000000, 0x00ebc8, 0x01c077,
478 	0x02209e, 0x01c1a4, 0x008e60, 0xfebe52, 0xfcd690,
479 	0xfb8fa5, 0xfba498, 0xfd9812, 0x0181ce, 0x06f5f3,
480 	0x0d112f, 0x12a958, 0x169686, 0x18000e, 0x169686,
481 	0x12a958, 0x0d112f, 0x06f5f3, 0x0181ce, 0xfd9812,
482 	0xfba498, 0xfb8fa5, 0xfcd690, 0xfebe52, 0x008e60,
483 	0x01c1a4, 0x02209e, 0x01c077, 0x00ebc8, 0x000000,
484 	0xff4c40, 0xfefbaf, 0xff0fef, 0xff6a18, 0xffdc4e,
485 	0x003c32, 0x006ff1, 0x0072aa, 0x0050c2, 0x001f4c,
486 	0xfff2a7, 0xffd7d1, 0xffd212, 0xffdca8, 0xffeece,
487 	0x000000, 0x000ae3, 0x000e21, 0x000b86, 0x000645,
488 	0x000147, 0xfffe32, 0xfffd45, 0xfffdce, 0xfffed9,
489 	0xffffb2, 0x000014,
490 };
491 
492 static const unsigned int lpf2_default_tap[] = {
493 	0x00050a, 0xfff004, 0x0002c1, 0x003c12, 0xffa818,
494 	0xffc87d, 0x010aef, 0xff5223, 0xfebd93, 0x028f41,
495 	0xff5c0e, 0xfc63f8, 0x055f81, 0x000000, 0xf478a0,
496 	0x11c5e3, 0x2ea74d, 0x11c5e3, 0xf478a0, 0x000000,
497 	0x055f81, 0xfc63f8, 0xff5c0e, 0x028f41, 0xfebd93,
498 	0xff5223, 0x010aef, 0xffc87d, 0xffa818, 0x003c12,
499 	0x0002c1, 0xfff004, 0x00050a,
500 };
501 
502 static const unsigned int lpf3_default_tap[] = {
503 	0x000000, 0x000081, 0x000000, 0xfffedb, 0x000000,
504 	0x00022d, 0x000000, 0xfffc46, 0x000000, 0x0005f7,
505 	0x000000, 0xfff6eb, 0x000000, 0x000d4e, 0x000000,
506 	0xffed1e, 0x000000, 0x001a1c, 0x000000, 0xffdcb0,
507 	0x000000, 0x002ede, 0x000000, 0xffc2d1, 0x000000,
508 	0x004ebe, 0x000000, 0xff9beb, 0x000000, 0x007dd7,
509 	0x000000, 0xff633a, 0x000000, 0x00c1d2, 0x000000,
510 	0xff11d5, 0x000000, 0x012368, 0x000000, 0xfe9c45,
511 	0x000000, 0x01b252, 0x000000, 0xfdebf6, 0x000000,
512 	0x0290b8, 0x000000, 0xfcca0d, 0x000000, 0x041d7c,
513 	0x000000, 0xfa8152, 0x000000, 0x07e9c6, 0x000000,
514 	0xf28fb5, 0x000000, 0x28b216, 0x3fffde, 0x28b216,
515 	0x000000, 0xf28fb5, 0x000000, 0x07e9c6, 0x000000,
516 	0xfa8152, 0x000000, 0x041d7c, 0x000000, 0xfcca0d,
517 	0x000000, 0x0290b8, 0x000000, 0xfdebf6, 0x000000,
518 	0x01b252, 0x000000, 0xfe9c45, 0x000000, 0x012368,
519 	0x000000, 0xff11d5, 0x000000, 0x00c1d2, 0x000000,
520 	0xff633a, 0x000000, 0x007dd7, 0x000000, 0xff9beb,
521 	0x000000, 0x004ebe, 0x000000, 0xffc2d1, 0x000000,
522 	0x002ede, 0x000000, 0xffdcb0, 0x000000, 0x001a1c,
523 	0x000000, 0xffed1e, 0x000000, 0x000d4e, 0x000000,
524 	0xfff6eb, 0x000000, 0x0005f7, 0x000000, 0xfffc46,
525 	0x000000, 0x00022d, 0x000000, 0xfffedb, 0x000000,
526 	0x000081, 0x000000,
527 };
528 
529 /*
530  * These values are sane defaults for the axg platform:
531  * - OS = 64
532  * - Latency = 38700 (?)
533  *
534  * TODO: There is a lot of different HCIC, LPFs and HPF configurations possible.
535  *       the configuration may depend on the dmic used by the platform, the
536  *       expected tradeoff between latency and quality, etc ... If/When other
537  *       settings are required, we should add a fw interface to this driver to
538  *       load new filter settings.
539  */
540 static const struct axg_pdm_filters axg_default_filters = {
541 	.hcic = {
542 		.shift = 0x15,
543 		.mult = 0x80,
544 		.steps = 7,
545 		.ds = 8,
546 	},
547 	.hpf = {
548 		.out_factor = 0x8000,
549 		.steps = 13,
550 	},
551 	.lpf = {
552 		[0] = {
553 			.ds = 2,
554 			.round_mode = 1,
555 			.tap = lpf1_default_tap,
556 			.tap_num = ARRAY_SIZE(lpf1_default_tap),
557 		},
558 		[1] = {
559 			.ds = 2,
560 			.round_mode = 0,
561 			.tap = lpf2_default_tap,
562 			.tap_num = ARRAY_SIZE(lpf2_default_tap),
563 		},
564 		[2] = {
565 			.ds = 2,
566 			.round_mode = 1,
567 			.tap = lpf3_default_tap,
568 			.tap_num = ARRAY_SIZE(lpf3_default_tap)
569 		},
570 	},
571 };
572 
573 static const struct axg_pdm_cfg axg_pdm_config = {
574 	.filters = &axg_default_filters,
575 	.sys_rate = 250000000,
576 };
577 
578 static const struct of_device_id axg_pdm_of_match[] = {
579 	{
580 		.compatible = "amlogic,axg-pdm",
581 		.data = &axg_pdm_config,
582 	}, {}
583 };
584 MODULE_DEVICE_TABLE(of, axg_pdm_of_match);
585 
586 static int axg_pdm_probe(struct platform_device *pdev)
587 {
588 	struct device *dev = &pdev->dev;
589 	struct axg_pdm *priv;
590 	void __iomem *regs;
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 	regs = devm_platform_ioremap_resource(pdev, 0);
604 	if (IS_ERR(regs))
605 		return PTR_ERR(regs);
606 
607 	priv->map = devm_regmap_init_mmio(dev, regs, &axg_pdm_regmap_cfg);
608 	if (IS_ERR(priv->map)) {
609 		dev_err(dev, "failed to init regmap: %ld\n",
610 			PTR_ERR(priv->map));
611 		return PTR_ERR(priv->map);
612 	}
613 
614 	priv->pclk = devm_clk_get(dev, "pclk");
615 	if (IS_ERR(priv->pclk))
616 		return dev_err_probe(dev, PTR_ERR(priv->pclk), "failed to get pclk\n");
617 
618 	priv->dclk = devm_clk_get(dev, "dclk");
619 	if (IS_ERR(priv->dclk))
620 		return dev_err_probe(dev, PTR_ERR(priv->dclk), "failed to get dclk\n");
621 
622 	priv->sysclk = devm_clk_get(dev, "sysclk");
623 	if (IS_ERR(priv->sysclk))
624 		return dev_err_probe(dev, PTR_ERR(priv->sysclk), "failed to get dclk\n");
625 
626 	return devm_snd_soc_register_component(dev, &axg_pdm_component_drv,
627 					       &axg_pdm_dai_drv, 1);
628 }
629 
630 static struct platform_driver axg_pdm_pdrv = {
631 	.probe = axg_pdm_probe,
632 	.driver = {
633 		.name = "axg-pdm",
634 		.of_match_table = axg_pdm_of_match,
635 	},
636 };
637 module_platform_driver(axg_pdm_pdrv);
638 
639 MODULE_DESCRIPTION("Amlogic AXG PDM Input driver");
640 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
641 MODULE_LICENSE("GPL v2");
642