1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * cx20442.c  --  CX20442 ALSA Soc Audio driver
4  *
5  * Copyright 2009 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
6  *
7  * Initially based on sound/soc/codecs/wm8400.c
8  * Copyright 2008, 2009 Wolfson Microelectronics PLC.
9  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
10  */
11 
12 #include <linux/tty.h>
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 
17 #include <sound/core.h>
18 #include <sound/initval.h>
19 #include <sound/soc.h>
20 
21 #include "cx20442.h"
22 
23 
24 struct cx20442_priv {
25 	struct tty_struct *tty;
26 	struct regulator *por;
27 	u8 reg_cache;
28 };
29 
30 #define CX20442_PM		0x0
31 
32 #define CX20442_TELIN		0
33 #define CX20442_TELOUT		1
34 #define CX20442_MIC		2
35 #define CX20442_SPKOUT		3
36 #define CX20442_AGC		4
37 
38 static const struct snd_soc_dapm_widget cx20442_dapm_widgets[] = {
39 	SND_SOC_DAPM_OUTPUT("TELOUT"),
40 	SND_SOC_DAPM_OUTPUT("SPKOUT"),
41 	SND_SOC_DAPM_OUTPUT("AGCOUT"),
42 
43 	SND_SOC_DAPM_MIXER("SPKOUT Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),
44 
45 	SND_SOC_DAPM_PGA("TELOUT Amp", CX20442_PM, CX20442_TELOUT, 0, NULL, 0),
46 	SND_SOC_DAPM_PGA("SPKOUT Amp", CX20442_PM, CX20442_SPKOUT, 0, NULL, 0),
47 	SND_SOC_DAPM_PGA("SPKOUT AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),
48 
49 	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
50 	SND_SOC_DAPM_ADC("ADC", "Capture", SND_SOC_NOPM, 0, 0),
51 
52 	SND_SOC_DAPM_MIXER("Input Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),
53 
54 	SND_SOC_DAPM_MICBIAS("TELIN Bias", CX20442_PM, CX20442_TELIN, 0),
55 	SND_SOC_DAPM_MICBIAS("MIC Bias", CX20442_PM, CX20442_MIC, 0),
56 
57 	SND_SOC_DAPM_PGA("MIC AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),
58 
59 	SND_SOC_DAPM_INPUT("TELIN"),
60 	SND_SOC_DAPM_INPUT("MIC"),
61 	SND_SOC_DAPM_INPUT("AGCIN"),
62 };
63 
64 static const struct snd_soc_dapm_route cx20442_audio_map[] = {
65 	{"TELOUT", NULL, "TELOUT Amp"},
66 
67 	{"SPKOUT", NULL, "SPKOUT Mixer"},
68 	{"SPKOUT Mixer", NULL, "SPKOUT Amp"},
69 
70 	{"TELOUT Amp", NULL, "DAC"},
71 	{"SPKOUT Amp", NULL, "DAC"},
72 
73 	{"SPKOUT Mixer", NULL, "SPKOUT AGC"},
74 	{"SPKOUT AGC", NULL, "AGCIN"},
75 
76 	{"AGCOUT", NULL, "MIC AGC"},
77 	{"MIC AGC", NULL, "MIC"},
78 
79 	{"MIC Bias", NULL, "MIC"},
80 	{"Input Mixer", NULL, "MIC Bias"},
81 
82 	{"TELIN Bias", NULL, "TELIN"},
83 	{"Input Mixer", NULL, "TELIN Bias"},
84 
85 	{"ADC", NULL, "Input Mixer"},
86 };
87 
cx20442_read_reg_cache(struct snd_soc_component * component,unsigned int reg)88 static unsigned int cx20442_read_reg_cache(struct snd_soc_component *component,
89 					   unsigned int reg)
90 {
91 	struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
92 
93 	if (reg >= 1)
94 		return -EINVAL;
95 
96 	return cx20442->reg_cache;
97 }
98 
99 enum v253_vls {
100 	V253_VLS_NONE = 0,
101 	V253_VLS_T,
102 	V253_VLS_L,
103 	V253_VLS_LT,
104 	V253_VLS_S,
105 	V253_VLS_ST,
106 	V253_VLS_M,
107 	V253_VLS_MST,
108 	V253_VLS_S1,
109 	V253_VLS_S1T,
110 	V253_VLS_MS1T,
111 	V253_VLS_M1,
112 	V253_VLS_M1ST,
113 	V253_VLS_M1S1T,
114 	V253_VLS_H,
115 	V253_VLS_HT,
116 	V253_VLS_MS,
117 	V253_VLS_MS1,
118 	V253_VLS_M1S,
119 	V253_VLS_M1S1,
120 	V253_VLS_TEST,
121 };
122 
cx20442_pm_to_v253_vls(u8 value)123 static int cx20442_pm_to_v253_vls(u8 value)
124 {
125 	switch (value & ~(1 << CX20442_AGC)) {
126 	case 0:
127 		return V253_VLS_T;
128 	case (1 << CX20442_SPKOUT):
129 	case (1 << CX20442_MIC):
130 	case (1 << CX20442_SPKOUT) | (1 << CX20442_MIC):
131 		return V253_VLS_M1S1;
132 	case (1 << CX20442_TELOUT):
133 	case (1 << CX20442_TELIN):
134 	case (1 << CX20442_TELOUT) | (1 << CX20442_TELIN):
135 		return V253_VLS_L;
136 	case (1 << CX20442_TELOUT) | (1 << CX20442_MIC):
137 		return V253_VLS_NONE;
138 	}
139 	return -EINVAL;
140 }
cx20442_pm_to_v253_vsp(u8 value)141 static int cx20442_pm_to_v253_vsp(u8 value)
142 {
143 	switch (value & ~(1 << CX20442_AGC)) {
144 	case (1 << CX20442_SPKOUT):
145 	case (1 << CX20442_MIC):
146 	case (1 << CX20442_SPKOUT) | (1 << CX20442_MIC):
147 		return (bool)(value & (1 << CX20442_AGC));
148 	}
149 	return (value & (1 << CX20442_AGC)) ? -EINVAL : 0;
150 }
151 
cx20442_write(struct snd_soc_component * component,unsigned int reg,unsigned int value)152 static int cx20442_write(struct snd_soc_component *component, unsigned int reg,
153 							unsigned int value)
154 {
155 	struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
156 	int vls, vsp, old, len;
157 	char buf[18];
158 
159 	if (reg >= 1)
160 		return -EINVAL;
161 
162 	/* tty and write pointers required for talking to the modem
163 	 * are expected to be set by the line discipline initialization code */
164 	if (!cx20442->tty || !cx20442->tty->ops->write)
165 		return -EIO;
166 
167 	old = cx20442->reg_cache;
168 	cx20442->reg_cache = value;
169 
170 	vls = cx20442_pm_to_v253_vls(value);
171 	if (vls < 0)
172 		return vls;
173 
174 	vsp = cx20442_pm_to_v253_vsp(value);
175 	if (vsp < 0)
176 		return vsp;
177 
178 	if ((vls == V253_VLS_T) ||
179 			(vls == cx20442_pm_to_v253_vls(old))) {
180 		if (vsp == cx20442_pm_to_v253_vsp(old))
181 			return 0;
182 		len = snprintf(buf, ARRAY_SIZE(buf), "at+vsp=%d\r", vsp);
183 	} else if (vsp == cx20442_pm_to_v253_vsp(old))
184 		len = snprintf(buf, ARRAY_SIZE(buf), "at+vls=%d\r", vls);
185 	else
186 		len = snprintf(buf, ARRAY_SIZE(buf),
187 					"at+vls=%d;+vsp=%d\r", vls, vsp);
188 
189 	if (unlikely(len > (ARRAY_SIZE(buf) - 1)))
190 		return -ENOMEM;
191 
192 	dev_dbg(component->dev, "%s: %s\n", __func__, buf);
193 	if (cx20442->tty->ops->write(cx20442->tty, buf, len) != len)
194 		return -EIO;
195 
196 	return 0;
197 }
198 
199 /*
200  * Line discpline related code
201  *
202  * Any of the callback functions below can be used in two ways:
203  * 1) registerd by a machine driver as one of line discipline operations,
204  * 2) called from a machine's provided line discipline callback function
205  *    in case when extra machine specific code must be run as well.
206  */
207 
208 /* Modem init: echo off, digital speaker off, quiet off, voice mode */
209 static const char v253_init[] = "ate0m0q0+fclass=8\r";
210 
211 /* Line discipline .open() */
v253_open(struct tty_struct * tty)212 static int v253_open(struct tty_struct *tty)
213 {
214 	int ret, len = strlen(v253_init);
215 
216 	/* Doesn't make sense without write callback */
217 	if (!tty->ops->write)
218 		return -EINVAL;
219 
220 	/* Won't work if no codec pointer has been passed by a card driver */
221 	if (!tty->disc_data)
222 		return -ENODEV;
223 
224 	tty->receive_room = 16;
225 	if (tty->ops->write(tty, v253_init, len) != len) {
226 		ret = -EIO;
227 		goto err;
228 	}
229 	/* Actual setup will be performed after the modem responds. */
230 	return 0;
231 err:
232 	tty->disc_data = NULL;
233 	return ret;
234 }
235 
236 /* Line discipline .close() */
v253_close(struct tty_struct * tty)237 static void v253_close(struct tty_struct *tty)
238 {
239 	struct snd_soc_component *component = tty->disc_data;
240 	struct cx20442_priv *cx20442;
241 
242 	tty->disc_data = NULL;
243 
244 	if (!component)
245 		return;
246 
247 	cx20442 = snd_soc_component_get_drvdata(component);
248 
249 	/* Prevent the codec driver from further accessing the modem */
250 	cx20442->tty = NULL;
251 	component->card->pop_time = 0;
252 }
253 
254 /* Line discipline .hangup() */
v253_hangup(struct tty_struct * tty)255 static void v253_hangup(struct tty_struct *tty)
256 {
257 	v253_close(tty);
258 }
259 
260 /* Line discipline .receive_buf() */
v253_receive(struct tty_struct * tty,const unsigned char * cp,const char * fp,int count)261 static void v253_receive(struct tty_struct *tty, const unsigned char *cp,
262 		const char *fp, int count)
263 {
264 	struct snd_soc_component *component = tty->disc_data;
265 	struct cx20442_priv *cx20442;
266 
267 	if (!component)
268 		return;
269 
270 	cx20442 = snd_soc_component_get_drvdata(component);
271 
272 	if (!cx20442->tty) {
273 		/* First modem response, complete setup procedure */
274 
275 		/* Set up codec driver access to modem controls */
276 		cx20442->tty = tty;
277 		component->card->pop_time = 1;
278 	}
279 }
280 
281 struct tty_ldisc_ops v253_ops = {
282 	.name = "cx20442",
283 	.owner = THIS_MODULE,
284 	.open = v253_open,
285 	.close = v253_close,
286 	.hangup = v253_hangup,
287 	.receive_buf = v253_receive,
288 };
289 EXPORT_SYMBOL_GPL(v253_ops);
290 
291 
292 /*
293  * Codec DAI
294  */
295 
296 static struct snd_soc_dai_driver cx20442_dai = {
297 	.name = "cx20442-voice",
298 	.playback = {
299 		.stream_name = "Playback",
300 		.channels_min = 1,
301 		.channels_max = 1,
302 		.rates = SNDRV_PCM_RATE_8000,
303 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
304 	},
305 	.capture = {
306 		.stream_name = "Capture",
307 		.channels_min = 1,
308 		.channels_max = 1,
309 		.rates = SNDRV_PCM_RATE_8000,
310 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
311 	},
312 };
313 
cx20442_set_bias_level(struct snd_soc_component * component,enum snd_soc_bias_level level)314 static int cx20442_set_bias_level(struct snd_soc_component *component,
315 		enum snd_soc_bias_level level)
316 {
317 	struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
318 	int err = 0;
319 
320 	switch (level) {
321 	case SND_SOC_BIAS_PREPARE:
322 		if (snd_soc_component_get_bias_level(component) != SND_SOC_BIAS_STANDBY)
323 			break;
324 		if (IS_ERR(cx20442->por))
325 			err = PTR_ERR(cx20442->por);
326 		else
327 			err = regulator_enable(cx20442->por);
328 		break;
329 	case SND_SOC_BIAS_STANDBY:
330 		if (snd_soc_component_get_bias_level(component) != SND_SOC_BIAS_PREPARE)
331 			break;
332 		if (IS_ERR(cx20442->por))
333 			err = PTR_ERR(cx20442->por);
334 		else
335 			err = regulator_disable(cx20442->por);
336 		break;
337 	default:
338 		break;
339 	}
340 
341 	return err;
342 }
343 
cx20442_component_probe(struct snd_soc_component * component)344 static int cx20442_component_probe(struct snd_soc_component *component)
345 {
346 	struct cx20442_priv *cx20442;
347 
348 	cx20442 = kzalloc(sizeof(struct cx20442_priv), GFP_KERNEL);
349 	if (cx20442 == NULL)
350 		return -ENOMEM;
351 
352 	cx20442->por = regulator_get(component->dev, "POR");
353 	if (IS_ERR(cx20442->por)) {
354 		int err = PTR_ERR(cx20442->por);
355 
356 		dev_warn(component->dev, "failed to get POR supply (%d)", err);
357 		/*
358 		 * When running on a non-dt platform and requested regulator
359 		 * is not available, regulator_get() never returns
360 		 * -EPROBE_DEFER as it is not able to justify if the regulator
361 		 * may still appear later.  On the other hand, the board can
362 		 * still set full constraints flag at late_initcall in order
363 		 * to instruct regulator_get() to return a dummy one if
364 		 * sufficient.  Hence, if we get -ENODEV here, let's convert
365 		 * it to -EPROBE_DEFER and wait for the board to decide or
366 		 * let Deferred Probe infrastructure handle this error.
367 		 */
368 		if (err == -ENODEV)
369 			err = -EPROBE_DEFER;
370 		kfree(cx20442);
371 		return err;
372 	}
373 
374 	cx20442->tty = NULL;
375 
376 	snd_soc_component_set_drvdata(component, cx20442);
377 	component->card->pop_time = 0;
378 
379 	return 0;
380 }
381 
382 /* power down chip */
cx20442_component_remove(struct snd_soc_component * component)383 static void cx20442_component_remove(struct snd_soc_component *component)
384 {
385 	struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
386 
387 	if (cx20442->tty) {
388 		struct tty_struct *tty = cx20442->tty;
389 		tty_hangup(tty);
390 	}
391 
392 	if (!IS_ERR(cx20442->por)) {
393 		/* should be already in STANDBY, hence disabled */
394 		regulator_put(cx20442->por);
395 	}
396 
397 	snd_soc_component_set_drvdata(component, NULL);
398 	kfree(cx20442);
399 }
400 
401 static const struct snd_soc_component_driver cx20442_component_dev = {
402 	.probe			= cx20442_component_probe,
403 	.remove			= cx20442_component_remove,
404 	.set_bias_level		= cx20442_set_bias_level,
405 	.read			= cx20442_read_reg_cache,
406 	.write			= cx20442_write,
407 	.dapm_widgets		= cx20442_dapm_widgets,
408 	.num_dapm_widgets	= ARRAY_SIZE(cx20442_dapm_widgets),
409 	.dapm_routes		= cx20442_audio_map,
410 	.num_dapm_routes	= ARRAY_SIZE(cx20442_audio_map),
411 	.idle_bias_on		= 1,
412 	.use_pmdown_time	= 1,
413 	.endianness		= 1,
414 	.non_legacy_dai_naming	= 1,
415 };
416 
cx20442_platform_probe(struct platform_device * pdev)417 static int cx20442_platform_probe(struct platform_device *pdev)
418 {
419 	return devm_snd_soc_register_component(&pdev->dev,
420 			&cx20442_component_dev, &cx20442_dai, 1);
421 }
422 
423 static struct platform_driver cx20442_platform_driver = {
424 	.driver = {
425 		.name = "cx20442-codec",
426 		},
427 	.probe = cx20442_platform_probe,
428 };
429 
430 module_platform_driver(cx20442_platform_driver);
431 
432 MODULE_DESCRIPTION("ASoC CX20442-11 voice modem codec driver");
433 MODULE_AUTHOR("Janusz Krzysztofik");
434 MODULE_LICENSE("GPL");
435 MODULE_ALIAS("platform:cx20442-codec");
436