xref: /openbmc/linux/sound/soc/codecs/tas6424.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ALSA SoC Texas Instruments TAS6424 Quad-Channel Audio Amplifier
4  *
5  * Copyright (C) 2016-2017 Texas Instruments Incorporated - https://www.ti.com/
6  *	Author: Andreas Dannenberg <dannenberg@ti.com>
7  *	Andrew F. Davis <afd@ti.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/errno.h>
12 #include <linux/device.h>
13 #include <linux/i2c.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/regmap.h>
16 #include <linux/slab.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/delay.h>
19 #include <linux/gpio/consumer.h>
20 
21 #include <sound/pcm.h>
22 #include <sound/pcm_params.h>
23 #include <sound/soc.h>
24 #include <sound/soc-dapm.h>
25 #include <sound/tlv.h>
26 
27 #include "tas6424.h"
28 
29 /* Define how often to check (and clear) the fault status register (in ms) */
30 #define TAS6424_FAULT_CHECK_INTERVAL 200
31 
32 static const char * const tas6424_supply_names[] = {
33 	"dvdd", /* Digital power supply. Connect to 3.3-V supply. */
34 	"vbat", /* Supply used for higher voltage analog circuits. */
35 	"pvdd", /* Class-D amp output FETs supply. */
36 };
37 #define TAS6424_NUM_SUPPLIES ARRAY_SIZE(tas6424_supply_names)
38 
39 struct tas6424_data {
40 	struct device *dev;
41 	struct regmap *regmap;
42 	struct regulator_bulk_data supplies[TAS6424_NUM_SUPPLIES];
43 	struct delayed_work fault_check_work;
44 	unsigned int last_cfault;
45 	unsigned int last_fault1;
46 	unsigned int last_fault2;
47 	unsigned int last_warn;
48 	struct gpio_desc *standby_gpio;
49 	struct gpio_desc *mute_gpio;
50 };
51 
52 /*
53  * DAC digital volumes. From -103.5 to 24 dB in 0.5 dB steps. Note that
54  * setting the gain below -100 dB (register value <0x7) is effectively a MUTE
55  * as per device datasheet.
56  */
57 static DECLARE_TLV_DB_SCALE(dac_tlv, -10350, 50, 0);
58 
59 static const struct snd_kcontrol_new tas6424_snd_controls[] = {
60 	SOC_SINGLE_TLV("Speaker Driver CH1 Playback Volume",
61 		       TAS6424_CH1_VOL_CTRL, 0, 0xff, 0, dac_tlv),
62 	SOC_SINGLE_TLV("Speaker Driver CH2 Playback Volume",
63 		       TAS6424_CH2_VOL_CTRL, 0, 0xff, 0, dac_tlv),
64 	SOC_SINGLE_TLV("Speaker Driver CH3 Playback Volume",
65 		       TAS6424_CH3_VOL_CTRL, 0, 0xff, 0, dac_tlv),
66 	SOC_SINGLE_TLV("Speaker Driver CH4 Playback Volume",
67 		       TAS6424_CH4_VOL_CTRL, 0, 0xff, 0, dac_tlv),
68 	SOC_SINGLE_STROBE("Auto Diagnostics Switch", TAS6424_DC_DIAG_CTRL1,
69 			  TAS6424_LDGBYPASS_SHIFT, 1),
70 };
71 
72 static int tas6424_dac_event(struct snd_soc_dapm_widget *w,
73 			     struct snd_kcontrol *kcontrol, int event)
74 {
75 	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
76 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
77 
78 	dev_dbg(component->dev, "%s() event=0x%0x\n", __func__, event);
79 
80 	if (event & SND_SOC_DAPM_POST_PMU) {
81 		/* Observe codec shutdown-to-active time */
82 		msleep(12);
83 
84 		/* Turn on TAS6424 periodic fault checking/handling */
85 		tas6424->last_fault1 = 0;
86 		tas6424->last_fault2 = 0;
87 		tas6424->last_warn = 0;
88 		schedule_delayed_work(&tas6424->fault_check_work,
89 				      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
90 	} else if (event & SND_SOC_DAPM_PRE_PMD) {
91 		/* Disable TAS6424 periodic fault checking/handling */
92 		cancel_delayed_work_sync(&tas6424->fault_check_work);
93 	}
94 
95 	return 0;
96 }
97 
98 static const struct snd_soc_dapm_widget tas6424_dapm_widgets[] = {
99 	SND_SOC_DAPM_AIF_IN("DAC IN", "Playback", 0, SND_SOC_NOPM, 0, 0),
100 	SND_SOC_DAPM_DAC_E("DAC", NULL, SND_SOC_NOPM, 0, 0, tas6424_dac_event,
101 			   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
102 	SND_SOC_DAPM_OUTPUT("OUT")
103 };
104 
105 static const struct snd_soc_dapm_route tas6424_audio_map[] = {
106 	{ "DAC", NULL, "DAC IN" },
107 	{ "OUT", NULL, "DAC" },
108 };
109 
110 static int tas6424_hw_params(struct snd_pcm_substream *substream,
111 			     struct snd_pcm_hw_params *params,
112 			     struct snd_soc_dai *dai)
113 {
114 	struct snd_soc_component *component = dai->component;
115 	unsigned int rate = params_rate(params);
116 	unsigned int width = params_width(params);
117 	u8 sap_ctrl = 0;
118 
119 	dev_dbg(component->dev, "%s() rate=%u width=%u\n", __func__, rate, width);
120 
121 	switch (rate) {
122 	case 44100:
123 		sap_ctrl |= TAS6424_SAP_RATE_44100;
124 		break;
125 	case 48000:
126 		sap_ctrl |= TAS6424_SAP_RATE_48000;
127 		break;
128 	case 96000:
129 		sap_ctrl |= TAS6424_SAP_RATE_96000;
130 		break;
131 	default:
132 		dev_err(component->dev, "unsupported sample rate: %u\n", rate);
133 		return -EINVAL;
134 	}
135 
136 	switch (width) {
137 	case 16:
138 		sap_ctrl |= TAS6424_SAP_TDM_SLOT_SZ_16;
139 		break;
140 	case 24:
141 		break;
142 	default:
143 		dev_err(component->dev, "unsupported sample width: %u\n", width);
144 		return -EINVAL;
145 	}
146 
147 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
148 			    TAS6424_SAP_RATE_MASK |
149 			    TAS6424_SAP_TDM_SLOT_SZ_16,
150 			    sap_ctrl);
151 
152 	return 0;
153 }
154 
155 static int tas6424_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
156 {
157 	struct snd_soc_component *component = dai->component;
158 	u8 serial_format = 0;
159 
160 	dev_dbg(component->dev, "%s() fmt=0x%0x\n", __func__, fmt);
161 
162 	/* clock masters */
163 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
164 	case SND_SOC_DAIFMT_CBS_CFS:
165 		break;
166 	default:
167 		dev_err(component->dev, "Invalid DAI master/slave interface\n");
168 		return -EINVAL;
169 	}
170 
171 	/* signal polarity */
172 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
173 	case SND_SOC_DAIFMT_NB_NF:
174 		break;
175 	default:
176 		dev_err(component->dev, "Invalid DAI clock signal polarity\n");
177 		return -EINVAL;
178 	}
179 
180 	/* interface format */
181 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
182 	case SND_SOC_DAIFMT_I2S:
183 		serial_format |= TAS6424_SAP_I2S;
184 		break;
185 	case SND_SOC_DAIFMT_DSP_A:
186 		serial_format |= TAS6424_SAP_DSP;
187 		break;
188 	case SND_SOC_DAIFMT_DSP_B:
189 		/*
190 		 * We can use the fact that the TAS6424 does not care about the
191 		 * LRCLK duty cycle during TDM to receive DSP_B formatted data
192 		 * in LEFTJ mode (no delaying of the 1st data bit).
193 		 */
194 		serial_format |= TAS6424_SAP_LEFTJ;
195 		break;
196 	case SND_SOC_DAIFMT_LEFT_J:
197 		serial_format |= TAS6424_SAP_LEFTJ;
198 		break;
199 	default:
200 		dev_err(component->dev, "Invalid DAI interface format\n");
201 		return -EINVAL;
202 	}
203 
204 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
205 			    TAS6424_SAP_FMT_MASK, serial_format);
206 
207 	return 0;
208 }
209 
210 static int tas6424_set_dai_tdm_slot(struct snd_soc_dai *dai,
211 				    unsigned int tx_mask, unsigned int rx_mask,
212 				    int slots, int slot_width)
213 {
214 	struct snd_soc_component *component = dai->component;
215 	unsigned int first_slot, last_slot;
216 	bool sap_tdm_slot_last;
217 
218 	dev_dbg(component->dev, "%s() tx_mask=%d rx_mask=%d\n", __func__,
219 		tx_mask, rx_mask);
220 
221 	if (!tx_mask || !rx_mask)
222 		return 0; /* nothing needed to disable TDM mode */
223 
224 	/*
225 	 * Determine the first slot and last slot that is being requested so
226 	 * we'll be able to more easily enforce certain constraints as the
227 	 * TAS6424's TDM interface is not fully configurable.
228 	 */
229 	first_slot = __ffs(tx_mask);
230 	last_slot = __fls(rx_mask);
231 
232 	if (last_slot - first_slot != 4) {
233 		dev_err(component->dev, "tdm mask must cover 4 contiguous slots\n");
234 		return -EINVAL;
235 	}
236 
237 	switch (first_slot) {
238 	case 0:
239 		sap_tdm_slot_last = false;
240 		break;
241 	case 4:
242 		sap_tdm_slot_last = true;
243 		break;
244 	default:
245 		dev_err(component->dev, "tdm mask must start at slot 0 or 4\n");
246 		return -EINVAL;
247 	}
248 
249 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL, TAS6424_SAP_TDM_SLOT_LAST,
250 			    sap_tdm_slot_last ? TAS6424_SAP_TDM_SLOT_LAST : 0);
251 
252 	return 0;
253 }
254 
255 static int tas6424_mute(struct snd_soc_dai *dai, int mute, int direction)
256 {
257 	struct snd_soc_component *component = dai->component;
258 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
259 	unsigned int val;
260 
261 	dev_dbg(component->dev, "%s() mute=%d\n", __func__, mute);
262 
263 	if (tas6424->mute_gpio) {
264 		gpiod_set_value_cansleep(tas6424->mute_gpio, mute);
265 		return 0;
266 	}
267 
268 	if (mute)
269 		val = TAS6424_ALL_STATE_MUTE;
270 	else
271 		val = TAS6424_ALL_STATE_PLAY;
272 
273 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, val);
274 
275 	return 0;
276 }
277 
278 static int tas6424_power_off(struct snd_soc_component *component)
279 {
280 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
281 	int ret;
282 
283 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, TAS6424_ALL_STATE_HIZ);
284 
285 	regcache_cache_only(tas6424->regmap, true);
286 	regcache_mark_dirty(tas6424->regmap);
287 
288 	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
289 				     tas6424->supplies);
290 	if (ret < 0) {
291 		dev_err(component->dev, "failed to disable supplies: %d\n", ret);
292 		return ret;
293 	}
294 
295 	return 0;
296 }
297 
298 static int tas6424_power_on(struct snd_soc_component *component)
299 {
300 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
301 	int ret;
302 	u8 chan_states;
303 	int no_auto_diags = 0;
304 	unsigned int reg_val;
305 
306 	if (!regmap_read(tas6424->regmap, TAS6424_DC_DIAG_CTRL1, &reg_val))
307 		no_auto_diags = reg_val & TAS6424_LDGBYPASS_MASK;
308 
309 	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
310 				    tas6424->supplies);
311 	if (ret < 0) {
312 		dev_err(component->dev, "failed to enable supplies: %d\n", ret);
313 		return ret;
314 	}
315 
316 	regcache_cache_only(tas6424->regmap, false);
317 
318 	ret = regcache_sync(tas6424->regmap);
319 	if (ret < 0) {
320 		dev_err(component->dev, "failed to sync regcache: %d\n", ret);
321 		return ret;
322 	}
323 
324 	if (tas6424->mute_gpio) {
325 		gpiod_set_value_cansleep(tas6424->mute_gpio, 0);
326 		/*
327 		 * channels are muted via the mute pin.  Don't also mute
328 		 * them via the registers so that subsequent register
329 		 * access is not necessary to un-mute the channels
330 		 */
331 		chan_states = TAS6424_ALL_STATE_PLAY;
332 	} else {
333 		chan_states = TAS6424_ALL_STATE_MUTE;
334 	}
335 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, chan_states);
336 
337 	/* any time we come out of HIZ, the output channels automatically run DC
338 	 * load diagnostics if autodiagnotics are enabled. wait here until this
339 	 * completes.
340 	 */
341 	if (!no_auto_diags)
342 		msleep(230);
343 
344 	return 0;
345 }
346 
347 static int tas6424_set_bias_level(struct snd_soc_component *component,
348 				  enum snd_soc_bias_level level)
349 {
350 	dev_dbg(component->dev, "%s() level=%d\n", __func__, level);
351 
352 	switch (level) {
353 	case SND_SOC_BIAS_ON:
354 	case SND_SOC_BIAS_PREPARE:
355 		break;
356 	case SND_SOC_BIAS_STANDBY:
357 		if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_OFF)
358 			tas6424_power_on(component);
359 		break;
360 	case SND_SOC_BIAS_OFF:
361 		tas6424_power_off(component);
362 		break;
363 	}
364 
365 	return 0;
366 }
367 
368 static struct snd_soc_component_driver soc_codec_dev_tas6424 = {
369 	.set_bias_level		= tas6424_set_bias_level,
370 	.controls		= tas6424_snd_controls,
371 	.num_controls		= ARRAY_SIZE(tas6424_snd_controls),
372 	.dapm_widgets		= tas6424_dapm_widgets,
373 	.num_dapm_widgets	= ARRAY_SIZE(tas6424_dapm_widgets),
374 	.dapm_routes		= tas6424_audio_map,
375 	.num_dapm_routes	= ARRAY_SIZE(tas6424_audio_map),
376 	.use_pmdown_time	= 1,
377 	.endianness		= 1,
378 	.non_legacy_dai_naming	= 1,
379 };
380 
381 static const struct snd_soc_dai_ops tas6424_speaker_dai_ops = {
382 	.hw_params	= tas6424_hw_params,
383 	.set_fmt	= tas6424_set_dai_fmt,
384 	.set_tdm_slot	= tas6424_set_dai_tdm_slot,
385 	.mute_stream	= tas6424_mute,
386 	.no_capture_mute = 1,
387 };
388 
389 static struct snd_soc_dai_driver tas6424_dai[] = {
390 	{
391 		.name = "tas6424-amplifier",
392 		.playback = {
393 			.stream_name = "Playback",
394 			.channels_min = 1,
395 			.channels_max = 4,
396 			.rates = TAS6424_RATES,
397 			.formats = TAS6424_FORMATS,
398 		},
399 		.ops = &tas6424_speaker_dai_ops,
400 	},
401 };
402 
403 static void tas6424_fault_check_work(struct work_struct *work)
404 {
405 	struct tas6424_data *tas6424 = container_of(work, struct tas6424_data,
406 						    fault_check_work.work);
407 	struct device *dev = tas6424->dev;
408 	unsigned int reg;
409 	int ret;
410 
411 	ret = regmap_read(tas6424->regmap, TAS6424_CHANNEL_FAULT, &reg);
412 	if (ret < 0) {
413 		dev_err(dev, "failed to read CHANNEL_FAULT register: %d\n", ret);
414 		goto out;
415 	}
416 
417 	if (!reg) {
418 		tas6424->last_cfault = reg;
419 		goto check_global_fault1_reg;
420 	}
421 
422 	/*
423 	 * Only flag errors once for a given occurrence. This is needed as
424 	 * the TAS6424 will take time clearing the fault condition internally
425 	 * during which we don't want to bombard the system with the same
426 	 * error message over and over.
427 	 */
428 	if ((reg & TAS6424_FAULT_OC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH1))
429 		dev_crit(dev, "experienced a channel 1 overcurrent fault\n");
430 
431 	if ((reg & TAS6424_FAULT_OC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH2))
432 		dev_crit(dev, "experienced a channel 2 overcurrent fault\n");
433 
434 	if ((reg & TAS6424_FAULT_OC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH3))
435 		dev_crit(dev, "experienced a channel 3 overcurrent fault\n");
436 
437 	if ((reg & TAS6424_FAULT_OC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH4))
438 		dev_crit(dev, "experienced a channel 4 overcurrent fault\n");
439 
440 	if ((reg & TAS6424_FAULT_DC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH1))
441 		dev_crit(dev, "experienced a channel 1 DC fault\n");
442 
443 	if ((reg & TAS6424_FAULT_DC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH2))
444 		dev_crit(dev, "experienced a channel 2 DC fault\n");
445 
446 	if ((reg & TAS6424_FAULT_DC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH3))
447 		dev_crit(dev, "experienced a channel 3 DC fault\n");
448 
449 	if ((reg & TAS6424_FAULT_DC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH4))
450 		dev_crit(dev, "experienced a channel 4 DC fault\n");
451 
452 	/* Store current fault1 value so we can detect any changes next time */
453 	tas6424->last_cfault = reg;
454 
455 check_global_fault1_reg:
456 	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT1, &reg);
457 	if (ret < 0) {
458 		dev_err(dev, "failed to read GLOB_FAULT1 register: %d\n", ret);
459 		goto out;
460 	}
461 
462 	/*
463 	 * Ignore any clock faults as there is no clean way to check for them.
464 	 * We would need to start checking for those faults *after* the SAIF
465 	 * stream has been setup, and stop checking *before* the stream is
466 	 * stopped to avoid any false-positives. However there are no
467 	 * appropriate hooks to monitor these events.
468 	 */
469 	reg &= TAS6424_FAULT_PVDD_OV |
470 	       TAS6424_FAULT_VBAT_OV |
471 	       TAS6424_FAULT_PVDD_UV |
472 	       TAS6424_FAULT_VBAT_UV;
473 
474 	if (!reg) {
475 		tas6424->last_fault1 = reg;
476 		goto check_global_fault2_reg;
477 	}
478 
479 	if ((reg & TAS6424_FAULT_PVDD_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_OV))
480 		dev_crit(dev, "experienced a PVDD overvoltage fault\n");
481 
482 	if ((reg & TAS6424_FAULT_VBAT_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_OV))
483 		dev_crit(dev, "experienced a VBAT overvoltage fault\n");
484 
485 	if ((reg & TAS6424_FAULT_PVDD_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_UV))
486 		dev_crit(dev, "experienced a PVDD undervoltage fault\n");
487 
488 	if ((reg & TAS6424_FAULT_VBAT_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_UV))
489 		dev_crit(dev, "experienced a VBAT undervoltage fault\n");
490 
491 	/* Store current fault1 value so we can detect any changes next time */
492 	tas6424->last_fault1 = reg;
493 
494 check_global_fault2_reg:
495 	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT2, &reg);
496 	if (ret < 0) {
497 		dev_err(dev, "failed to read GLOB_FAULT2 register: %d\n", ret);
498 		goto out;
499 	}
500 
501 	reg &= TAS6424_FAULT_OTSD |
502 	       TAS6424_FAULT_OTSD_CH1 |
503 	       TAS6424_FAULT_OTSD_CH2 |
504 	       TAS6424_FAULT_OTSD_CH3 |
505 	       TAS6424_FAULT_OTSD_CH4;
506 
507 	if (!reg) {
508 		tas6424->last_fault2 = reg;
509 		goto check_warn_reg;
510 	}
511 
512 	if ((reg & TAS6424_FAULT_OTSD) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD))
513 		dev_crit(dev, "experienced a global overtemp shutdown\n");
514 
515 	if ((reg & TAS6424_FAULT_OTSD_CH1) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH1))
516 		dev_crit(dev, "experienced an overtemp shutdown on CH1\n");
517 
518 	if ((reg & TAS6424_FAULT_OTSD_CH2) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH2))
519 		dev_crit(dev, "experienced an overtemp shutdown on CH2\n");
520 
521 	if ((reg & TAS6424_FAULT_OTSD_CH3) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH3))
522 		dev_crit(dev, "experienced an overtemp shutdown on CH3\n");
523 
524 	if ((reg & TAS6424_FAULT_OTSD_CH4) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH4))
525 		dev_crit(dev, "experienced an overtemp shutdown on CH4\n");
526 
527 	/* Store current fault2 value so we can detect any changes next time */
528 	tas6424->last_fault2 = reg;
529 
530 check_warn_reg:
531 	ret = regmap_read(tas6424->regmap, TAS6424_WARN, &reg);
532 	if (ret < 0) {
533 		dev_err(dev, "failed to read WARN register: %d\n", ret);
534 		goto out;
535 	}
536 
537 	reg &= TAS6424_WARN_VDD_UV |
538 	       TAS6424_WARN_VDD_POR |
539 	       TAS6424_WARN_VDD_OTW |
540 	       TAS6424_WARN_VDD_OTW_CH1 |
541 	       TAS6424_WARN_VDD_OTW_CH2 |
542 	       TAS6424_WARN_VDD_OTW_CH3 |
543 	       TAS6424_WARN_VDD_OTW_CH4;
544 
545 	if (!reg) {
546 		tas6424->last_warn = reg;
547 		goto out;
548 	}
549 
550 	if ((reg & TAS6424_WARN_VDD_UV) && !(tas6424->last_warn & TAS6424_WARN_VDD_UV))
551 		dev_warn(dev, "experienced a VDD under voltage condition\n");
552 
553 	if ((reg & TAS6424_WARN_VDD_POR) && !(tas6424->last_warn & TAS6424_WARN_VDD_POR))
554 		dev_warn(dev, "experienced a VDD POR condition\n");
555 
556 	if ((reg & TAS6424_WARN_VDD_OTW) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW))
557 		dev_warn(dev, "experienced a global overtemp warning\n");
558 
559 	if ((reg & TAS6424_WARN_VDD_OTW_CH1) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH1))
560 		dev_warn(dev, "experienced an overtemp warning on CH1\n");
561 
562 	if ((reg & TAS6424_WARN_VDD_OTW_CH2) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH2))
563 		dev_warn(dev, "experienced an overtemp warning on CH2\n");
564 
565 	if ((reg & TAS6424_WARN_VDD_OTW_CH3) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH3))
566 		dev_warn(dev, "experienced an overtemp warning on CH3\n");
567 
568 	if ((reg & TAS6424_WARN_VDD_OTW_CH4) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH4))
569 		dev_warn(dev, "experienced an overtemp warning on CH4\n");
570 
571 	/* Store current warn value so we can detect any changes next time */
572 	tas6424->last_warn = reg;
573 
574 	/* Clear any warnings by toggling the CLEAR_FAULT control bit */
575 	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
576 				TAS6424_CLEAR_FAULT, TAS6424_CLEAR_FAULT);
577 	if (ret < 0)
578 		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);
579 
580 	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
581 				TAS6424_CLEAR_FAULT, 0);
582 	if (ret < 0)
583 		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);
584 
585 out:
586 	/* Schedule the next fault check at the specified interval */
587 	schedule_delayed_work(&tas6424->fault_check_work,
588 			      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
589 }
590 
591 static const struct reg_default tas6424_reg_defaults[] = {
592 	{ TAS6424_MODE_CTRL,		0x00 },
593 	{ TAS6424_MISC_CTRL1,		0x32 },
594 	{ TAS6424_MISC_CTRL2,		0x62 },
595 	{ TAS6424_SAP_CTRL,		0x04 },
596 	{ TAS6424_CH_STATE_CTRL,	0x55 },
597 	{ TAS6424_CH1_VOL_CTRL,		0xcf },
598 	{ TAS6424_CH2_VOL_CTRL,		0xcf },
599 	{ TAS6424_CH3_VOL_CTRL,		0xcf },
600 	{ TAS6424_CH4_VOL_CTRL,		0xcf },
601 	{ TAS6424_DC_DIAG_CTRL1,	0x00 },
602 	{ TAS6424_DC_DIAG_CTRL2,	0x11 },
603 	{ TAS6424_DC_DIAG_CTRL3,	0x11 },
604 	{ TAS6424_PIN_CTRL,		0xff },
605 	{ TAS6424_AC_DIAG_CTRL1,	0x00 },
606 	{ TAS6424_MISC_CTRL3,		0x00 },
607 	{ TAS6424_CLIP_CTRL,		0x01 },
608 	{ TAS6424_CLIP_WINDOW,		0x14 },
609 	{ TAS6424_CLIP_WARN,		0x00 },
610 	{ TAS6424_CBC_STAT,		0x00 },
611 	{ TAS6424_MISC_CTRL4,		0x40 },
612 };
613 
614 static bool tas6424_is_writable_reg(struct device *dev, unsigned int reg)
615 {
616 	switch (reg) {
617 	case TAS6424_MODE_CTRL:
618 	case TAS6424_MISC_CTRL1:
619 	case TAS6424_MISC_CTRL2:
620 	case TAS6424_SAP_CTRL:
621 	case TAS6424_CH_STATE_CTRL:
622 	case TAS6424_CH1_VOL_CTRL:
623 	case TAS6424_CH2_VOL_CTRL:
624 	case TAS6424_CH3_VOL_CTRL:
625 	case TAS6424_CH4_VOL_CTRL:
626 	case TAS6424_DC_DIAG_CTRL1:
627 	case TAS6424_DC_DIAG_CTRL2:
628 	case TAS6424_DC_DIAG_CTRL3:
629 	case TAS6424_PIN_CTRL:
630 	case TAS6424_AC_DIAG_CTRL1:
631 	case TAS6424_MISC_CTRL3:
632 	case TAS6424_CLIP_CTRL:
633 	case TAS6424_CLIP_WINDOW:
634 	case TAS6424_CLIP_WARN:
635 	case TAS6424_CBC_STAT:
636 	case TAS6424_MISC_CTRL4:
637 		return true;
638 	default:
639 		return false;
640 	}
641 }
642 
643 static bool tas6424_is_volatile_reg(struct device *dev, unsigned int reg)
644 {
645 	switch (reg) {
646 	case TAS6424_DC_LOAD_DIAG_REP12:
647 	case TAS6424_DC_LOAD_DIAG_REP34:
648 	case TAS6424_DC_LOAD_DIAG_REPLO:
649 	case TAS6424_CHANNEL_STATE:
650 	case TAS6424_CHANNEL_FAULT:
651 	case TAS6424_GLOB_FAULT1:
652 	case TAS6424_GLOB_FAULT2:
653 	case TAS6424_WARN:
654 	case TAS6424_AC_LOAD_DIAG_REP1:
655 	case TAS6424_AC_LOAD_DIAG_REP2:
656 	case TAS6424_AC_LOAD_DIAG_REP3:
657 	case TAS6424_AC_LOAD_DIAG_REP4:
658 		return true;
659 	default:
660 		return false;
661 	}
662 }
663 
664 static const struct regmap_config tas6424_regmap_config = {
665 	.reg_bits = 8,
666 	.val_bits = 8,
667 
668 	.writeable_reg = tas6424_is_writable_reg,
669 	.volatile_reg = tas6424_is_volatile_reg,
670 
671 	.max_register = TAS6424_MAX,
672 	.reg_defaults = tas6424_reg_defaults,
673 	.num_reg_defaults = ARRAY_SIZE(tas6424_reg_defaults),
674 	.cache_type = REGCACHE_RBTREE,
675 };
676 
677 #if IS_ENABLED(CONFIG_OF)
678 static const struct of_device_id tas6424_of_ids[] = {
679 	{ .compatible = "ti,tas6424", },
680 	{ },
681 };
682 MODULE_DEVICE_TABLE(of, tas6424_of_ids);
683 #endif
684 
685 static int tas6424_i2c_probe(struct i2c_client *client,
686 			     const struct i2c_device_id *id)
687 {
688 	struct device *dev = &client->dev;
689 	struct tas6424_data *tas6424;
690 	int ret;
691 	int i;
692 
693 	tas6424 = devm_kzalloc(dev, sizeof(*tas6424), GFP_KERNEL);
694 	if (!tas6424)
695 		return -ENOMEM;
696 	dev_set_drvdata(dev, tas6424);
697 
698 	tas6424->dev = dev;
699 
700 	tas6424->regmap = devm_regmap_init_i2c(client, &tas6424_regmap_config);
701 	if (IS_ERR(tas6424->regmap)) {
702 		ret = PTR_ERR(tas6424->regmap);
703 		dev_err(dev, "unable to allocate register map: %d\n", ret);
704 		return ret;
705 	}
706 
707 	/*
708 	 * Get control of the standby pin and set it LOW to take the codec
709 	 * out of the stand-by mode.
710 	 * Note: The actual pin polarity is taken care of in the GPIO lib
711 	 * according the polarity specified in the DTS.
712 	 */
713 	tas6424->standby_gpio = devm_gpiod_get_optional(dev, "standby",
714 						      GPIOD_OUT_LOW);
715 	if (IS_ERR(tas6424->standby_gpio)) {
716 		if (PTR_ERR(tas6424->standby_gpio) == -EPROBE_DEFER)
717 			return -EPROBE_DEFER;
718 		dev_info(dev, "failed to get standby GPIO: %ld\n",
719 			PTR_ERR(tas6424->standby_gpio));
720 		tas6424->standby_gpio = NULL;
721 	}
722 
723 	/*
724 	 * Get control of the mute pin and set it HIGH in order to start with
725 	 * all the output muted.
726 	 * Note: The actual pin polarity is taken care of in the GPIO lib
727 	 * according the polarity specified in the DTS.
728 	 */
729 	tas6424->mute_gpio = devm_gpiod_get_optional(dev, "mute",
730 						      GPIOD_OUT_HIGH);
731 	if (IS_ERR(tas6424->mute_gpio)) {
732 		if (PTR_ERR(tas6424->mute_gpio) == -EPROBE_DEFER)
733 			return -EPROBE_DEFER;
734 		dev_info(dev, "failed to get nmute GPIO: %ld\n",
735 			PTR_ERR(tas6424->mute_gpio));
736 		tas6424->mute_gpio = NULL;
737 	}
738 
739 	for (i = 0; i < ARRAY_SIZE(tas6424->supplies); i++)
740 		tas6424->supplies[i].supply = tas6424_supply_names[i];
741 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(tas6424->supplies),
742 				      tas6424->supplies);
743 	if (ret) {
744 		dev_err(dev, "unable to request supplies: %d\n", ret);
745 		return ret;
746 	}
747 
748 	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
749 				    tas6424->supplies);
750 	if (ret) {
751 		dev_err(dev, "unable to enable supplies: %d\n", ret);
752 		return ret;
753 	}
754 
755 	/* Reset device to establish well-defined startup state */
756 	ret = regmap_update_bits(tas6424->regmap, TAS6424_MODE_CTRL,
757 				 TAS6424_RESET, TAS6424_RESET);
758 	if (ret) {
759 		dev_err(dev, "unable to reset device: %d\n", ret);
760 		return ret;
761 	}
762 
763 	INIT_DELAYED_WORK(&tas6424->fault_check_work, tas6424_fault_check_work);
764 
765 	ret = devm_snd_soc_register_component(dev, &soc_codec_dev_tas6424,
766 				     tas6424_dai, ARRAY_SIZE(tas6424_dai));
767 	if (ret < 0) {
768 		dev_err(dev, "unable to register codec: %d\n", ret);
769 		return ret;
770 	}
771 
772 	return 0;
773 }
774 
775 static int tas6424_i2c_remove(struct i2c_client *client)
776 {
777 	struct device *dev = &client->dev;
778 	struct tas6424_data *tas6424 = dev_get_drvdata(dev);
779 	int ret;
780 
781 	cancel_delayed_work_sync(&tas6424->fault_check_work);
782 
783 	/* put the codec in stand-by */
784 	if (tas6424->standby_gpio)
785 		gpiod_set_value_cansleep(tas6424->standby_gpio, 1);
786 
787 	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
788 				     tas6424->supplies);
789 	if (ret < 0) {
790 		dev_err(dev, "unable to disable supplies: %d\n", ret);
791 		return ret;
792 	}
793 
794 	return 0;
795 }
796 
797 static const struct i2c_device_id tas6424_i2c_ids[] = {
798 	{ "tas6424", 0 },
799 	{ }
800 };
801 MODULE_DEVICE_TABLE(i2c, tas6424_i2c_ids);
802 
803 static struct i2c_driver tas6424_i2c_driver = {
804 	.driver = {
805 		.name = "tas6424",
806 		.of_match_table = of_match_ptr(tas6424_of_ids),
807 	},
808 	.probe = tas6424_i2c_probe,
809 	.remove = tas6424_i2c_remove,
810 	.id_table = tas6424_i2c_ids,
811 };
812 module_i2c_driver(tas6424_i2c_driver);
813 
814 MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
815 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
816 MODULE_DESCRIPTION("TAS6424 Audio amplifier driver");
817 MODULE_LICENSE("GPL v2");
818