xref: /linux/sound/soc/codecs/tas6424.c (revision 1b0975ee3bdd3eb19a47371c26fd7ef8f7f6b599)
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/regmap.h>
15 #include <linux/slab.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/delay.h>
18 #include <linux/gpio/consumer.h>
19 
20 #include <sound/pcm.h>
21 #include <sound/pcm_params.h>
22 #include <sound/soc.h>
23 #include <sound/soc-dapm.h>
24 #include <sound/tlv.h>
25 
26 #include "tas6424.h"
27 
28 /* Define how often to check (and clear) the fault status register (in ms) */
29 #define TAS6424_FAULT_CHECK_INTERVAL 200
30 
31 static const char * const tas6424_supply_names[] = {
32 	"dvdd", /* Digital power supply. Connect to 3.3-V supply. */
33 	"vbat", /* Supply used for higher voltage analog circuits. */
34 	"pvdd", /* Class-D amp output FETs supply. */
35 };
36 #define TAS6424_NUM_SUPPLIES ARRAY_SIZE(tas6424_supply_names)
37 
38 struct tas6424_data {
39 	struct device *dev;
40 	struct regmap *regmap;
41 	struct regulator_bulk_data supplies[TAS6424_NUM_SUPPLIES];
42 	struct delayed_work fault_check_work;
43 	unsigned int last_cfault;
44 	unsigned int last_fault1;
45 	unsigned int last_fault2;
46 	unsigned int last_warn;
47 	struct gpio_desc *standby_gpio;
48 	struct gpio_desc *mute_gpio;
49 };
50 
51 /*
52  * DAC digital volumes. From -103.5 to 24 dB in 0.5 dB steps. Note that
53  * setting the gain below -100 dB (register value <0x7) is effectively a MUTE
54  * as per device datasheet.
55  */
56 static DECLARE_TLV_DB_SCALE(dac_tlv, -10350, 50, 0);
57 
58 static const struct snd_kcontrol_new tas6424_snd_controls[] = {
59 	SOC_SINGLE_TLV("Speaker Driver CH1 Playback Volume",
60 		       TAS6424_CH1_VOL_CTRL, 0, 0xff, 0, dac_tlv),
61 	SOC_SINGLE_TLV("Speaker Driver CH2 Playback Volume",
62 		       TAS6424_CH2_VOL_CTRL, 0, 0xff, 0, dac_tlv),
63 	SOC_SINGLE_TLV("Speaker Driver CH3 Playback Volume",
64 		       TAS6424_CH3_VOL_CTRL, 0, 0xff, 0, dac_tlv),
65 	SOC_SINGLE_TLV("Speaker Driver CH4 Playback Volume",
66 		       TAS6424_CH4_VOL_CTRL, 0, 0xff, 0, dac_tlv),
67 	SOC_SINGLE_STROBE("Auto Diagnostics Switch", TAS6424_DC_DIAG_CTRL1,
68 			  TAS6424_LDGBYPASS_SHIFT, 1),
69 };
70 
71 static int tas6424_dac_event(struct snd_soc_dapm_widget *w,
72 			     struct snd_kcontrol *kcontrol, int event)
73 {
74 	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
75 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
76 
77 	dev_dbg(component->dev, "%s() event=0x%0x\n", __func__, event);
78 
79 	if (event & SND_SOC_DAPM_POST_PMU) {
80 		/* Observe codec shutdown-to-active time */
81 		msleep(12);
82 
83 		/* Turn on TAS6424 periodic fault checking/handling */
84 		tas6424->last_fault1 = 0;
85 		tas6424->last_fault2 = 0;
86 		tas6424->last_warn = 0;
87 		schedule_delayed_work(&tas6424->fault_check_work,
88 				      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
89 	} else if (event & SND_SOC_DAPM_PRE_PMD) {
90 		/* Disable TAS6424 periodic fault checking/handling */
91 		cancel_delayed_work_sync(&tas6424->fault_check_work);
92 	}
93 
94 	return 0;
95 }
96 
97 static const struct snd_soc_dapm_widget tas6424_dapm_widgets[] = {
98 	SND_SOC_DAPM_AIF_IN("DAC IN", "Playback", 0, SND_SOC_NOPM, 0, 0),
99 	SND_SOC_DAPM_DAC_E("DAC", NULL, SND_SOC_NOPM, 0, 0, tas6424_dac_event,
100 			   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
101 	SND_SOC_DAPM_OUTPUT("OUT")
102 };
103 
104 static const struct snd_soc_dapm_route tas6424_audio_map[] = {
105 	{ "DAC", NULL, "DAC IN" },
106 	{ "OUT", NULL, "DAC" },
107 };
108 
109 static int tas6424_hw_params(struct snd_pcm_substream *substream,
110 			     struct snd_pcm_hw_params *params,
111 			     struct snd_soc_dai *dai)
112 {
113 	struct snd_soc_component *component = dai->component;
114 	unsigned int rate = params_rate(params);
115 	unsigned int width = params_width(params);
116 	u8 sap_ctrl = 0;
117 
118 	dev_dbg(component->dev, "%s() rate=%u width=%u\n", __func__, rate, width);
119 
120 	switch (rate) {
121 	case 44100:
122 		sap_ctrl |= TAS6424_SAP_RATE_44100;
123 		break;
124 	case 48000:
125 		sap_ctrl |= TAS6424_SAP_RATE_48000;
126 		break;
127 	case 96000:
128 		sap_ctrl |= TAS6424_SAP_RATE_96000;
129 		break;
130 	default:
131 		dev_err(component->dev, "unsupported sample rate: %u\n", rate);
132 		return -EINVAL;
133 	}
134 
135 	switch (width) {
136 	case 16:
137 		sap_ctrl |= TAS6424_SAP_TDM_SLOT_SZ_16;
138 		break;
139 	case 24:
140 		break;
141 	default:
142 		dev_err(component->dev, "unsupported sample width: %u\n", width);
143 		return -EINVAL;
144 	}
145 
146 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
147 			    TAS6424_SAP_RATE_MASK |
148 			    TAS6424_SAP_TDM_SLOT_SZ_16,
149 			    sap_ctrl);
150 
151 	return 0;
152 }
153 
154 static int tas6424_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
155 {
156 	struct snd_soc_component *component = dai->component;
157 	u8 serial_format = 0;
158 
159 	dev_dbg(component->dev, "%s() fmt=0x%0x\n", __func__, fmt);
160 
161 	/* clock masters */
162 	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
163 	case SND_SOC_DAIFMT_CBC_CFC:
164 		break;
165 	default:
166 		dev_err(component->dev, "Invalid DAI clocking\n");
167 		return -EINVAL;
168 	}
169 
170 	/* signal polarity */
171 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
172 	case SND_SOC_DAIFMT_NB_NF:
173 		break;
174 	default:
175 		dev_err(component->dev, "Invalid DAI clock signal polarity\n");
176 		return -EINVAL;
177 	}
178 
179 	/* interface format */
180 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
181 	case SND_SOC_DAIFMT_I2S:
182 		serial_format |= TAS6424_SAP_I2S;
183 		break;
184 	case SND_SOC_DAIFMT_DSP_A:
185 		serial_format |= TAS6424_SAP_DSP;
186 		break;
187 	case SND_SOC_DAIFMT_DSP_B:
188 		/*
189 		 * We can use the fact that the TAS6424 does not care about the
190 		 * LRCLK duty cycle during TDM to receive DSP_B formatted data
191 		 * in LEFTJ mode (no delaying of the 1st data bit).
192 		 */
193 		serial_format |= TAS6424_SAP_LEFTJ;
194 		break;
195 	case SND_SOC_DAIFMT_LEFT_J:
196 		serial_format |= TAS6424_SAP_LEFTJ;
197 		break;
198 	default:
199 		dev_err(component->dev, "Invalid DAI interface format\n");
200 		return -EINVAL;
201 	}
202 
203 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
204 			    TAS6424_SAP_FMT_MASK, serial_format);
205 
206 	return 0;
207 }
208 
209 static int tas6424_set_dai_tdm_slot(struct snd_soc_dai *dai,
210 				    unsigned int tx_mask, unsigned int rx_mask,
211 				    int slots, int slot_width)
212 {
213 	struct snd_soc_component *component = dai->component;
214 	unsigned int first_slot, last_slot;
215 	bool sap_tdm_slot_last;
216 
217 	dev_dbg(component->dev, "%s() tx_mask=%d rx_mask=%d\n", __func__,
218 		tx_mask, rx_mask);
219 
220 	if (!tx_mask || !rx_mask)
221 		return 0; /* nothing needed to disable TDM mode */
222 
223 	/*
224 	 * Determine the first slot and last slot that is being requested so
225 	 * we'll be able to more easily enforce certain constraints as the
226 	 * TAS6424's TDM interface is not fully configurable.
227 	 */
228 	first_slot = __ffs(tx_mask);
229 	last_slot = __fls(rx_mask);
230 
231 	if (last_slot - first_slot != 4) {
232 		dev_err(component->dev, "tdm mask must cover 4 contiguous slots\n");
233 		return -EINVAL;
234 	}
235 
236 	switch (first_slot) {
237 	case 0:
238 		sap_tdm_slot_last = false;
239 		break;
240 	case 4:
241 		sap_tdm_slot_last = true;
242 		break;
243 	default:
244 		dev_err(component->dev, "tdm mask must start at slot 0 or 4\n");
245 		return -EINVAL;
246 	}
247 
248 	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL, TAS6424_SAP_TDM_SLOT_LAST,
249 			    sap_tdm_slot_last ? TAS6424_SAP_TDM_SLOT_LAST : 0);
250 
251 	return 0;
252 }
253 
254 static int tas6424_mute(struct snd_soc_dai *dai, int mute, int direction)
255 {
256 	struct snd_soc_component *component = dai->component;
257 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
258 	unsigned int val;
259 
260 	dev_dbg(component->dev, "%s() mute=%d\n", __func__, mute);
261 
262 	if (tas6424->mute_gpio) {
263 		gpiod_set_value_cansleep(tas6424->mute_gpio, mute);
264 		return 0;
265 	}
266 
267 	if (mute)
268 		val = TAS6424_ALL_STATE_MUTE;
269 	else
270 		val = TAS6424_ALL_STATE_PLAY;
271 
272 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, val);
273 
274 	return 0;
275 }
276 
277 static int tas6424_power_off(struct snd_soc_component *component)
278 {
279 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
280 	int ret;
281 
282 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, TAS6424_ALL_STATE_HIZ);
283 
284 	regcache_cache_only(tas6424->regmap, true);
285 	regcache_mark_dirty(tas6424->regmap);
286 
287 	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
288 				     tas6424->supplies);
289 	if (ret < 0) {
290 		dev_err(component->dev, "failed to disable supplies: %d\n", ret);
291 		return ret;
292 	}
293 
294 	return 0;
295 }
296 
297 static int tas6424_power_on(struct snd_soc_component *component)
298 {
299 	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
300 	int ret;
301 	u8 chan_states;
302 	int no_auto_diags = 0;
303 	unsigned int reg_val;
304 
305 	if (!regmap_read(tas6424->regmap, TAS6424_DC_DIAG_CTRL1, &reg_val))
306 		no_auto_diags = reg_val & TAS6424_LDGBYPASS_MASK;
307 
308 	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
309 				    tas6424->supplies);
310 	if (ret < 0) {
311 		dev_err(component->dev, "failed to enable supplies: %d\n", ret);
312 		return ret;
313 	}
314 
315 	regcache_cache_only(tas6424->regmap, false);
316 
317 	ret = regcache_sync(tas6424->regmap);
318 	if (ret < 0) {
319 		dev_err(component->dev, "failed to sync regcache: %d\n", ret);
320 		return ret;
321 	}
322 
323 	if (tas6424->mute_gpio) {
324 		gpiod_set_value_cansleep(tas6424->mute_gpio, 0);
325 		/*
326 		 * channels are muted via the mute pin.  Don't also mute
327 		 * them via the registers so that subsequent register
328 		 * access is not necessary to un-mute the channels
329 		 */
330 		chan_states = TAS6424_ALL_STATE_PLAY;
331 	} else {
332 		chan_states = TAS6424_ALL_STATE_MUTE;
333 	}
334 	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, chan_states);
335 
336 	/* any time we come out of HIZ, the output channels automatically run DC
337 	 * load diagnostics if autodiagnotics are enabled. wait here until this
338 	 * completes.
339 	 */
340 	if (!no_auto_diags)
341 		msleep(230);
342 
343 	return 0;
344 }
345 
346 static int tas6424_set_bias_level(struct snd_soc_component *component,
347 				  enum snd_soc_bias_level level)
348 {
349 	dev_dbg(component->dev, "%s() level=%d\n", __func__, level);
350 
351 	switch (level) {
352 	case SND_SOC_BIAS_ON:
353 	case SND_SOC_BIAS_PREPARE:
354 		break;
355 	case SND_SOC_BIAS_STANDBY:
356 		if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_OFF)
357 			tas6424_power_on(component);
358 		break;
359 	case SND_SOC_BIAS_OFF:
360 		tas6424_power_off(component);
361 		break;
362 	}
363 
364 	return 0;
365 }
366 
367 static struct snd_soc_component_driver soc_codec_dev_tas6424 = {
368 	.set_bias_level		= tas6424_set_bias_level,
369 	.controls		= tas6424_snd_controls,
370 	.num_controls		= ARRAY_SIZE(tas6424_snd_controls),
371 	.dapm_widgets		= tas6424_dapm_widgets,
372 	.num_dapm_widgets	= ARRAY_SIZE(tas6424_dapm_widgets),
373 	.dapm_routes		= tas6424_audio_map,
374 	.num_dapm_routes	= ARRAY_SIZE(tas6424_audio_map),
375 	.use_pmdown_time	= 1,
376 	.endianness		= 1,
377 };
378 
379 static const struct snd_soc_dai_ops tas6424_speaker_dai_ops = {
380 	.hw_params	= tas6424_hw_params,
381 	.set_fmt	= tas6424_set_dai_fmt,
382 	.set_tdm_slot	= tas6424_set_dai_tdm_slot,
383 	.mute_stream	= tas6424_mute,
384 	.no_capture_mute = 1,
385 };
386 
387 static struct snd_soc_dai_driver tas6424_dai[] = {
388 	{
389 		.name = "tas6424-amplifier",
390 		.playback = {
391 			.stream_name = "Playback",
392 			.channels_min = 1,
393 			.channels_max = 4,
394 			.rates = TAS6424_RATES,
395 			.formats = TAS6424_FORMATS,
396 		},
397 		.ops = &tas6424_speaker_dai_ops,
398 	},
399 };
400 
401 static void tas6424_fault_check_work(struct work_struct *work)
402 {
403 	struct tas6424_data *tas6424 = container_of(work, struct tas6424_data,
404 						    fault_check_work.work);
405 	struct device *dev = tas6424->dev;
406 	unsigned int reg;
407 	int ret;
408 
409 	ret = regmap_read(tas6424->regmap, TAS6424_CHANNEL_FAULT, &reg);
410 	if (ret < 0) {
411 		dev_err(dev, "failed to read CHANNEL_FAULT register: %d\n", ret);
412 		goto out;
413 	}
414 
415 	if (!reg) {
416 		tas6424->last_cfault = reg;
417 		goto check_global_fault1_reg;
418 	}
419 
420 	/*
421 	 * Only flag errors once for a given occurrence. This is needed as
422 	 * the TAS6424 will take time clearing the fault condition internally
423 	 * during which we don't want to bombard the system with the same
424 	 * error message over and over.
425 	 */
426 	if ((reg & TAS6424_FAULT_OC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH1))
427 		dev_crit(dev, "experienced a channel 1 overcurrent fault\n");
428 
429 	if ((reg & TAS6424_FAULT_OC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH2))
430 		dev_crit(dev, "experienced a channel 2 overcurrent fault\n");
431 
432 	if ((reg & TAS6424_FAULT_OC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH3))
433 		dev_crit(dev, "experienced a channel 3 overcurrent fault\n");
434 
435 	if ((reg & TAS6424_FAULT_OC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH4))
436 		dev_crit(dev, "experienced a channel 4 overcurrent fault\n");
437 
438 	if ((reg & TAS6424_FAULT_DC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH1))
439 		dev_crit(dev, "experienced a channel 1 DC fault\n");
440 
441 	if ((reg & TAS6424_FAULT_DC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH2))
442 		dev_crit(dev, "experienced a channel 2 DC fault\n");
443 
444 	if ((reg & TAS6424_FAULT_DC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH3))
445 		dev_crit(dev, "experienced a channel 3 DC fault\n");
446 
447 	if ((reg & TAS6424_FAULT_DC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH4))
448 		dev_crit(dev, "experienced a channel 4 DC fault\n");
449 
450 	/* Store current fault1 value so we can detect any changes next time */
451 	tas6424->last_cfault = reg;
452 
453 check_global_fault1_reg:
454 	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT1, &reg);
455 	if (ret < 0) {
456 		dev_err(dev, "failed to read GLOB_FAULT1 register: %d\n", ret);
457 		goto out;
458 	}
459 
460 	/*
461 	 * Ignore any clock faults as there is no clean way to check for them.
462 	 * We would need to start checking for those faults *after* the SAIF
463 	 * stream has been setup, and stop checking *before* the stream is
464 	 * stopped to avoid any false-positives. However there are no
465 	 * appropriate hooks to monitor these events.
466 	 */
467 	reg &= TAS6424_FAULT_PVDD_OV |
468 	       TAS6424_FAULT_VBAT_OV |
469 	       TAS6424_FAULT_PVDD_UV |
470 	       TAS6424_FAULT_VBAT_UV;
471 
472 	if (!reg) {
473 		tas6424->last_fault1 = reg;
474 		goto check_global_fault2_reg;
475 	}
476 
477 	if ((reg & TAS6424_FAULT_PVDD_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_OV))
478 		dev_crit(dev, "experienced a PVDD overvoltage fault\n");
479 
480 	if ((reg & TAS6424_FAULT_VBAT_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_OV))
481 		dev_crit(dev, "experienced a VBAT overvoltage fault\n");
482 
483 	if ((reg & TAS6424_FAULT_PVDD_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_UV))
484 		dev_crit(dev, "experienced a PVDD undervoltage fault\n");
485 
486 	if ((reg & TAS6424_FAULT_VBAT_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_UV))
487 		dev_crit(dev, "experienced a VBAT undervoltage fault\n");
488 
489 	/* Store current fault1 value so we can detect any changes next time */
490 	tas6424->last_fault1 = reg;
491 
492 check_global_fault2_reg:
493 	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT2, &reg);
494 	if (ret < 0) {
495 		dev_err(dev, "failed to read GLOB_FAULT2 register: %d\n", ret);
496 		goto out;
497 	}
498 
499 	reg &= TAS6424_FAULT_OTSD |
500 	       TAS6424_FAULT_OTSD_CH1 |
501 	       TAS6424_FAULT_OTSD_CH2 |
502 	       TAS6424_FAULT_OTSD_CH3 |
503 	       TAS6424_FAULT_OTSD_CH4;
504 
505 	if (!reg) {
506 		tas6424->last_fault2 = reg;
507 		goto check_warn_reg;
508 	}
509 
510 	if ((reg & TAS6424_FAULT_OTSD) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD))
511 		dev_crit(dev, "experienced a global overtemp shutdown\n");
512 
513 	if ((reg & TAS6424_FAULT_OTSD_CH1) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH1))
514 		dev_crit(dev, "experienced an overtemp shutdown on CH1\n");
515 
516 	if ((reg & TAS6424_FAULT_OTSD_CH2) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH2))
517 		dev_crit(dev, "experienced an overtemp shutdown on CH2\n");
518 
519 	if ((reg & TAS6424_FAULT_OTSD_CH3) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH3))
520 		dev_crit(dev, "experienced an overtemp shutdown on CH3\n");
521 
522 	if ((reg & TAS6424_FAULT_OTSD_CH4) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH4))
523 		dev_crit(dev, "experienced an overtemp shutdown on CH4\n");
524 
525 	/* Store current fault2 value so we can detect any changes next time */
526 	tas6424->last_fault2 = reg;
527 
528 check_warn_reg:
529 	ret = regmap_read(tas6424->regmap, TAS6424_WARN, &reg);
530 	if (ret < 0) {
531 		dev_err(dev, "failed to read WARN register: %d\n", ret);
532 		goto out;
533 	}
534 
535 	reg &= TAS6424_WARN_VDD_UV |
536 	       TAS6424_WARN_VDD_POR |
537 	       TAS6424_WARN_VDD_OTW |
538 	       TAS6424_WARN_VDD_OTW_CH1 |
539 	       TAS6424_WARN_VDD_OTW_CH2 |
540 	       TAS6424_WARN_VDD_OTW_CH3 |
541 	       TAS6424_WARN_VDD_OTW_CH4;
542 
543 	if (!reg) {
544 		tas6424->last_warn = reg;
545 		goto out;
546 	}
547 
548 	if ((reg & TAS6424_WARN_VDD_UV) && !(tas6424->last_warn & TAS6424_WARN_VDD_UV))
549 		dev_warn(dev, "experienced a VDD under voltage condition\n");
550 
551 	if ((reg & TAS6424_WARN_VDD_POR) && !(tas6424->last_warn & TAS6424_WARN_VDD_POR))
552 		dev_warn(dev, "experienced a VDD POR condition\n");
553 
554 	if ((reg & TAS6424_WARN_VDD_OTW) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW))
555 		dev_warn(dev, "experienced a global overtemp warning\n");
556 
557 	if ((reg & TAS6424_WARN_VDD_OTW_CH1) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH1))
558 		dev_warn(dev, "experienced an overtemp warning on CH1\n");
559 
560 	if ((reg & TAS6424_WARN_VDD_OTW_CH2) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH2))
561 		dev_warn(dev, "experienced an overtemp warning on CH2\n");
562 
563 	if ((reg & TAS6424_WARN_VDD_OTW_CH3) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH3))
564 		dev_warn(dev, "experienced an overtemp warning on CH3\n");
565 
566 	if ((reg & TAS6424_WARN_VDD_OTW_CH4) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH4))
567 		dev_warn(dev, "experienced an overtemp warning on CH4\n");
568 
569 	/* Store current warn value so we can detect any changes next time */
570 	tas6424->last_warn = reg;
571 
572 	/* Clear any warnings by toggling the CLEAR_FAULT control bit */
573 	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
574 				TAS6424_CLEAR_FAULT, TAS6424_CLEAR_FAULT);
575 	if (ret < 0)
576 		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);
577 
578 	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
579 				TAS6424_CLEAR_FAULT, 0);
580 	if (ret < 0)
581 		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);
582 
583 out:
584 	/* Schedule the next fault check at the specified interval */
585 	schedule_delayed_work(&tas6424->fault_check_work,
586 			      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
587 }
588 
589 static const struct reg_default tas6424_reg_defaults[] = {
590 	{ TAS6424_MODE_CTRL,		0x00 },
591 	{ TAS6424_MISC_CTRL1,		0x32 },
592 	{ TAS6424_MISC_CTRL2,		0x62 },
593 	{ TAS6424_SAP_CTRL,		0x04 },
594 	{ TAS6424_CH_STATE_CTRL,	0x55 },
595 	{ TAS6424_CH1_VOL_CTRL,		0xcf },
596 	{ TAS6424_CH2_VOL_CTRL,		0xcf },
597 	{ TAS6424_CH3_VOL_CTRL,		0xcf },
598 	{ TAS6424_CH4_VOL_CTRL,		0xcf },
599 	{ TAS6424_DC_DIAG_CTRL1,	0x00 },
600 	{ TAS6424_DC_DIAG_CTRL2,	0x11 },
601 	{ TAS6424_DC_DIAG_CTRL3,	0x11 },
602 	{ TAS6424_PIN_CTRL,		0xff },
603 	{ TAS6424_AC_DIAG_CTRL1,	0x00 },
604 	{ TAS6424_MISC_CTRL3,		0x00 },
605 	{ TAS6424_CLIP_CTRL,		0x01 },
606 	{ TAS6424_CLIP_WINDOW,		0x14 },
607 	{ TAS6424_CLIP_WARN,		0x00 },
608 	{ TAS6424_CBC_STAT,		0x00 },
609 	{ TAS6424_MISC_CTRL4,		0x40 },
610 };
611 
612 static bool tas6424_is_writable_reg(struct device *dev, unsigned int reg)
613 {
614 	switch (reg) {
615 	case TAS6424_MODE_CTRL:
616 	case TAS6424_MISC_CTRL1:
617 	case TAS6424_MISC_CTRL2:
618 	case TAS6424_SAP_CTRL:
619 	case TAS6424_CH_STATE_CTRL:
620 	case TAS6424_CH1_VOL_CTRL:
621 	case TAS6424_CH2_VOL_CTRL:
622 	case TAS6424_CH3_VOL_CTRL:
623 	case TAS6424_CH4_VOL_CTRL:
624 	case TAS6424_DC_DIAG_CTRL1:
625 	case TAS6424_DC_DIAG_CTRL2:
626 	case TAS6424_DC_DIAG_CTRL3:
627 	case TAS6424_PIN_CTRL:
628 	case TAS6424_AC_DIAG_CTRL1:
629 	case TAS6424_MISC_CTRL3:
630 	case TAS6424_CLIP_CTRL:
631 	case TAS6424_CLIP_WINDOW:
632 	case TAS6424_CLIP_WARN:
633 	case TAS6424_CBC_STAT:
634 	case TAS6424_MISC_CTRL4:
635 		return true;
636 	default:
637 		return false;
638 	}
639 }
640 
641 static bool tas6424_is_volatile_reg(struct device *dev, unsigned int reg)
642 {
643 	switch (reg) {
644 	case TAS6424_DC_LOAD_DIAG_REP12:
645 	case TAS6424_DC_LOAD_DIAG_REP34:
646 	case TAS6424_DC_LOAD_DIAG_REPLO:
647 	case TAS6424_CHANNEL_STATE:
648 	case TAS6424_CHANNEL_FAULT:
649 	case TAS6424_GLOB_FAULT1:
650 	case TAS6424_GLOB_FAULT2:
651 	case TAS6424_WARN:
652 	case TAS6424_AC_LOAD_DIAG_REP1:
653 	case TAS6424_AC_LOAD_DIAG_REP2:
654 	case TAS6424_AC_LOAD_DIAG_REP3:
655 	case TAS6424_AC_LOAD_DIAG_REP4:
656 		return true;
657 	default:
658 		return false;
659 	}
660 }
661 
662 static const struct regmap_config tas6424_regmap_config = {
663 	.reg_bits = 8,
664 	.val_bits = 8,
665 
666 	.writeable_reg = tas6424_is_writable_reg,
667 	.volatile_reg = tas6424_is_volatile_reg,
668 
669 	.max_register = TAS6424_MAX,
670 	.reg_defaults = tas6424_reg_defaults,
671 	.num_reg_defaults = ARRAY_SIZE(tas6424_reg_defaults),
672 	.cache_type = REGCACHE_RBTREE,
673 };
674 
675 #if IS_ENABLED(CONFIG_OF)
676 static const struct of_device_id tas6424_of_ids[] = {
677 	{ .compatible = "ti,tas6424", },
678 	{ },
679 };
680 MODULE_DEVICE_TABLE(of, tas6424_of_ids);
681 #endif
682 
683 static int tas6424_i2c_probe(struct i2c_client *client)
684 {
685 	struct device *dev = &client->dev;
686 	struct tas6424_data *tas6424;
687 	int ret;
688 	int i;
689 
690 	tas6424 = devm_kzalloc(dev, sizeof(*tas6424), GFP_KERNEL);
691 	if (!tas6424)
692 		return -ENOMEM;
693 	dev_set_drvdata(dev, tas6424);
694 
695 	tas6424->dev = dev;
696 
697 	tas6424->regmap = devm_regmap_init_i2c(client, &tas6424_regmap_config);
698 	if (IS_ERR(tas6424->regmap)) {
699 		ret = PTR_ERR(tas6424->regmap);
700 		dev_err(dev, "unable to allocate register map: %d\n", ret);
701 		return ret;
702 	}
703 
704 	/*
705 	 * Get control of the standby pin and set it LOW to take the codec
706 	 * out of the stand-by mode.
707 	 * Note: The actual pin polarity is taken care of in the GPIO lib
708 	 * according the polarity specified in the DTS.
709 	 */
710 	tas6424->standby_gpio = devm_gpiod_get_optional(dev, "standby",
711 						      GPIOD_OUT_LOW);
712 	if (IS_ERR(tas6424->standby_gpio)) {
713 		if (PTR_ERR(tas6424->standby_gpio) == -EPROBE_DEFER)
714 			return -EPROBE_DEFER;
715 		dev_info(dev, "failed to get standby GPIO: %ld\n",
716 			PTR_ERR(tas6424->standby_gpio));
717 		tas6424->standby_gpio = NULL;
718 	}
719 
720 	/*
721 	 * Get control of the mute pin and set it HIGH in order to start with
722 	 * all the output muted.
723 	 * Note: The actual pin polarity is taken care of in the GPIO lib
724 	 * according the polarity specified in the DTS.
725 	 */
726 	tas6424->mute_gpio = devm_gpiod_get_optional(dev, "mute",
727 						      GPIOD_OUT_HIGH);
728 	if (IS_ERR(tas6424->mute_gpio)) {
729 		if (PTR_ERR(tas6424->mute_gpio) == -EPROBE_DEFER)
730 			return -EPROBE_DEFER;
731 		dev_info(dev, "failed to get nmute GPIO: %ld\n",
732 			PTR_ERR(tas6424->mute_gpio));
733 		tas6424->mute_gpio = NULL;
734 	}
735 
736 	for (i = 0; i < ARRAY_SIZE(tas6424->supplies); i++)
737 		tas6424->supplies[i].supply = tas6424_supply_names[i];
738 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(tas6424->supplies),
739 				      tas6424->supplies);
740 	if (ret) {
741 		dev_err(dev, "unable to request supplies: %d\n", ret);
742 		return ret;
743 	}
744 
745 	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
746 				    tas6424->supplies);
747 	if (ret) {
748 		dev_err(dev, "unable to enable supplies: %d\n", ret);
749 		return ret;
750 	}
751 
752 	/* Reset device to establish well-defined startup state */
753 	ret = regmap_update_bits(tas6424->regmap, TAS6424_MODE_CTRL,
754 				 TAS6424_RESET, TAS6424_RESET);
755 	if (ret) {
756 		dev_err(dev, "unable to reset device: %d\n", ret);
757 		goto disable_regs;
758 	}
759 
760 	INIT_DELAYED_WORK(&tas6424->fault_check_work, tas6424_fault_check_work);
761 
762 	ret = devm_snd_soc_register_component(dev, &soc_codec_dev_tas6424,
763 				     tas6424_dai, ARRAY_SIZE(tas6424_dai));
764 	if (ret < 0) {
765 		dev_err(dev, "unable to register codec: %d\n", ret);
766 		goto disable_regs;
767 	}
768 
769 	return 0;
770 
771 disable_regs:
772 	regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies), tas6424->supplies);
773 	return ret;
774 }
775 
776 static void tas6424_i2c_remove(struct i2c_client *client)
777 {
778 	struct device *dev = &client->dev;
779 	struct tas6424_data *tas6424 = dev_get_drvdata(dev);
780 	int ret;
781 
782 	cancel_delayed_work_sync(&tas6424->fault_check_work);
783 
784 	/* put the codec in stand-by */
785 	if (tas6424->standby_gpio)
786 		gpiod_set_value_cansleep(tas6424->standby_gpio, 1);
787 
788 	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
789 				     tas6424->supplies);
790 	if (ret < 0)
791 		dev_err(dev, "unable to disable supplies: %d\n", ret);
792 }
793 
794 static const struct i2c_device_id tas6424_i2c_ids[] = {
795 	{ "tas6424", 0 },
796 	{ }
797 };
798 MODULE_DEVICE_TABLE(i2c, tas6424_i2c_ids);
799 
800 static struct i2c_driver tas6424_i2c_driver = {
801 	.driver = {
802 		.name = "tas6424",
803 		.of_match_table = of_match_ptr(tas6424_of_ids),
804 	},
805 	.probe = tas6424_i2c_probe,
806 	.remove = tas6424_i2c_remove,
807 	.id_table = tas6424_i2c_ids,
808 };
809 module_i2c_driver(tas6424_i2c_driver);
810 
811 MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
812 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
813 MODULE_DESCRIPTION("TAS6424 Audio amplifier driver");
814 MODULE_LICENSE("GPL v2");
815