• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/bitops.h>
15 #include <linux/completion.h>
16 #include <linux/delay.h>
17 #include <linux/err.h>
18 #include <linux/iio/iio.h>
19 #include <linux/interrupt.h>
20 #include <linux/kernel.h>
21 #include <linux/math64.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/platform_device.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 #include <linux/log2.h>
28 
29 #include <dt-bindings/iio/qcom,spmi-vadc.h>
30 
31 /* VADC register and bit definitions */
32 #define VADC_REVISION2				0x1
33 #define VADC_REVISION2_SUPPORTED_VADC		1
34 
35 #define VADC_PERPH_TYPE				0x4
36 #define VADC_PERPH_TYPE_ADC			8
37 
38 #define VADC_PERPH_SUBTYPE			0x5
39 #define VADC_PERPH_SUBTYPE_VADC			1
40 
41 #define VADC_STATUS1				0x8
42 #define VADC_STATUS1_OP_MODE			4
43 #define VADC_STATUS1_REQ_STS			BIT(1)
44 #define VADC_STATUS1_EOC			BIT(0)
45 #define VADC_STATUS1_REQ_STS_EOC_MASK		0x3
46 
47 #define VADC_MODE_CTL				0x40
48 #define VADC_OP_MODE_SHIFT			3
49 #define VADC_OP_MODE_NORMAL			0
50 #define VADC_AMUX_TRIM_EN			BIT(1)
51 #define VADC_ADC_TRIM_EN			BIT(0)
52 
53 #define VADC_EN_CTL1				0x46
54 #define VADC_EN_CTL1_SET			BIT(7)
55 
56 #define VADC_ADC_CH_SEL_CTL			0x48
57 
58 #define VADC_ADC_DIG_PARAM			0x50
59 #define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT	2
60 
61 #define VADC_HW_SETTLE_DELAY			0x51
62 
63 #define VADC_CONV_REQ				0x52
64 #define VADC_CONV_REQ_SET			BIT(7)
65 
66 #define VADC_FAST_AVG_CTL			0x5a
67 #define VADC_FAST_AVG_EN			0x5b
68 #define VADC_FAST_AVG_EN_SET			BIT(7)
69 
70 #define VADC_ACCESS				0xd0
71 #define VADC_ACCESS_DATA			0xa5
72 
73 #define VADC_PERH_RESET_CTL3			0xda
74 #define VADC_FOLLOW_WARM_RB			BIT(2)
75 
76 #define VADC_DATA				0x60	/* 16 bits */
77 
78 #define VADC_CONV_TIME_MIN_US			2000
79 #define VADC_CONV_TIME_MAX_US			2100
80 
81 /* Min ADC code represents 0V */
82 #define VADC_MIN_ADC_CODE			0x6000
83 /* Max ADC code represents full-scale range of 1.8V */
84 #define VADC_MAX_ADC_CODE			0xa800
85 
86 #define VADC_ABSOLUTE_RANGE_UV			625000
87 #define VADC_RATIOMETRIC_RANGE_UV		1800000
88 
89 #define VADC_DEF_PRESCALING			0 /* 1:1 */
90 #define VADC_DEF_DECIMATION			0 /* 512 */
91 #define VADC_DEF_HW_SETTLE_TIME			0 /* 0 us */
92 #define VADC_DEF_AVG_SAMPLES			0 /* 1 sample */
93 #define VADC_DEF_CALIB_TYPE			VADC_CALIB_ABSOLUTE
94 
95 #define VADC_DECIMATION_MIN			512
96 #define VADC_DECIMATION_MAX			4096
97 
98 #define VADC_HW_SETTLE_DELAY_MAX		10000
99 #define VADC_AVG_SAMPLES_MAX			512
100 
101 #define KELVINMIL_CELSIUSMIL			273150
102 
103 #define VADC_CHAN_MIN			VADC_USBIN
104 #define VADC_CHAN_MAX			VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM
105 
106 /*
107  * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
108  * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
109  * calibration.
110  */
111 enum vadc_calibration {
112 	VADC_CALIB_ABSOLUTE = 0,
113 	VADC_CALIB_RATIOMETRIC
114 };
115 
116 /**
117  * struct vadc_linear_graph - Represent ADC characteristics.
118  * @dy: numerator slope to calculate the gain.
119  * @dx: denominator slope to calculate the gain.
120  * @gnd: A/D word of the ground reference used for the channel.
121  *
122  * Each ADC device has different offset and gain parameters which are
123  * computed to calibrate the device.
124  */
125 struct vadc_linear_graph {
126 	s32 dy;
127 	s32 dx;
128 	s32 gnd;
129 };
130 
131 /**
132  * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
133  * @num: the inverse numerator of the gain applied to the input channel.
134  * @den: the inverse denominator of the gain applied to the input channel.
135  */
136 struct vadc_prescale_ratio {
137 	u32 num;
138 	u32 den;
139 };
140 
141 /**
142  * struct vadc_channel_prop - VADC channel property.
143  * @channel: channel number, refer to the channel list.
144  * @calibration: calibration type.
145  * @decimation: sampling rate supported for the channel.
146  * @prescale: channel scaling performed on the input signal.
147  * @hw_settle_time: the time between AMUX being configured and the
148  *	start of conversion.
149  * @avg_samples: ability to provide single result from the ADC
150  *	that is an average of multiple measurements.
151  */
152 struct vadc_channel_prop {
153 	unsigned int channel;
154 	enum vadc_calibration calibration;
155 	unsigned int decimation;
156 	unsigned int prescale;
157 	unsigned int hw_settle_time;
158 	unsigned int avg_samples;
159 };
160 
161 /**
162  * struct vadc_priv - VADC private structure.
163  * @regmap: pointer to struct regmap.
164  * @dev: pointer to struct device.
165  * @base: base address for the ADC peripheral.
166  * @nchannels: number of VADC channels.
167  * @chan_props: array of VADC channel properties.
168  * @iio_chans: array of IIO channels specification.
169  * @are_ref_measured: are reference points measured.
170  * @poll_eoc: use polling instead of interrupt.
171  * @complete: VADC result notification after interrupt is received.
172  * @graph: store parameters for calibration.
173  * @lock: ADC lock for access to the peripheral.
174  */
175 struct vadc_priv {
176 	struct regmap		 *regmap;
177 	struct device		 *dev;
178 	u16			 base;
179 	unsigned int		 nchannels;
180 	struct vadc_channel_prop *chan_props;
181 	struct iio_chan_spec	 *iio_chans;
182 	bool			 are_ref_measured;
183 	bool			 poll_eoc;
184 	struct completion	 complete;
185 	struct vadc_linear_graph graph[2];
186 	struct mutex		 lock;
187 };
188 
189 static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
190 	{.num =  1, .den =  1},
191 	{.num =  1, .den =  3},
192 	{.num =  1, .den =  4},
193 	{.num =  1, .den =  6},
194 	{.num =  1, .den = 20},
195 	{.num =  1, .den =  8},
196 	{.num = 10, .den = 81},
197 	{.num =  1, .den = 10}
198 };
199 
vadc_read(struct vadc_priv * vadc,u16 offset,u8 * data)200 static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
201 {
202 	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
203 }
204 
vadc_write(struct vadc_priv * vadc,u16 offset,u8 data)205 static int vadc_write(struct vadc_priv *vadc, u16 offset, u8 data)
206 {
207 	return regmap_write(vadc->regmap, vadc->base + offset, data);
208 }
209 
vadc_reset(struct vadc_priv * vadc)210 static int vadc_reset(struct vadc_priv *vadc)
211 {
212 	u8 data;
213 	int ret;
214 
215 	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
216 	if (ret)
217 		return ret;
218 
219 	ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
220 	if (ret)
221 		return ret;
222 
223 	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
224 	if (ret)
225 		return ret;
226 
227 	data |= VADC_FOLLOW_WARM_RB;
228 
229 	return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
230 }
231 
vadc_set_state(struct vadc_priv * vadc,bool state)232 static int vadc_set_state(struct vadc_priv *vadc, bool state)
233 {
234 	return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
235 }
236 
vadc_show_status(struct vadc_priv * vadc)237 static void vadc_show_status(struct vadc_priv *vadc)
238 {
239 	u8 mode, sta1, chan, dig, en, req;
240 	int ret;
241 
242 	ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
243 	if (ret)
244 		return;
245 
246 	ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
247 	if (ret)
248 		return;
249 
250 	ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
251 	if (ret)
252 		return;
253 
254 	ret = vadc_read(vadc, VADC_CONV_REQ, &req);
255 	if (ret)
256 		return;
257 
258 	ret = vadc_read(vadc, VADC_STATUS1, &sta1);
259 	if (ret)
260 		return;
261 
262 	ret = vadc_read(vadc, VADC_EN_CTL1, &en);
263 	if (ret)
264 		return;
265 
266 	dev_err(vadc->dev,
267 		"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
268 		mode, en, chan, dig, req, sta1);
269 }
270 
vadc_configure(struct vadc_priv * vadc,struct vadc_channel_prop * prop)271 static int vadc_configure(struct vadc_priv *vadc,
272 			  struct vadc_channel_prop *prop)
273 {
274 	u8 decimation, mode_ctrl;
275 	int ret;
276 
277 	/* Mode selection */
278 	mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
279 		     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
280 	ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
281 	if (ret)
282 		return ret;
283 
284 	/* Channel selection */
285 	ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
286 	if (ret)
287 		return ret;
288 
289 	/* Digital parameter setup */
290 	decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
291 	ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
292 	if (ret)
293 		return ret;
294 
295 	/* HW settle time delay */
296 	ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
297 	if (ret)
298 		return ret;
299 
300 	ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
301 	if (ret)
302 		return ret;
303 
304 	if (prop->avg_samples)
305 		ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
306 	else
307 		ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);
308 
309 	return ret;
310 }
311 
vadc_poll_wait_eoc(struct vadc_priv * vadc,unsigned int interval_us)312 static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
313 {
314 	unsigned int count, retry;
315 	u8 sta1;
316 	int ret;
317 
318 	retry = interval_us / VADC_CONV_TIME_MIN_US;
319 
320 	for (count = 0; count < retry; count++) {
321 		ret = vadc_read(vadc, VADC_STATUS1, &sta1);
322 		if (ret)
323 			return ret;
324 
325 		sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
326 		if (sta1 == VADC_STATUS1_EOC)
327 			return 0;
328 
329 		usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
330 	}
331 
332 	vadc_show_status(vadc);
333 
334 	return -ETIMEDOUT;
335 }
336 
vadc_read_result(struct vadc_priv * vadc,u16 * data)337 static int vadc_read_result(struct vadc_priv *vadc, u16 *data)
338 {
339 	int ret;
340 
341 	ret = regmap_bulk_read(vadc->regmap, vadc->base + VADC_DATA, data, 2);
342 	if (ret)
343 		return ret;
344 
345 	*data = clamp_t(u16, *data, VADC_MIN_ADC_CODE, VADC_MAX_ADC_CODE);
346 
347 	return 0;
348 }
349 
vadc_get_channel(struct vadc_priv * vadc,unsigned int num)350 static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
351 						  unsigned int num)
352 {
353 	unsigned int i;
354 
355 	for (i = 0; i < vadc->nchannels; i++)
356 		if (vadc->chan_props[i].channel == num)
357 			return &vadc->chan_props[i];
358 
359 	dev_dbg(vadc->dev, "no such channel %02x\n", num);
360 
361 	return NULL;
362 }
363 
vadc_do_conversion(struct vadc_priv * vadc,struct vadc_channel_prop * prop,u16 * data)364 static int vadc_do_conversion(struct vadc_priv *vadc,
365 			      struct vadc_channel_prop *prop, u16 *data)
366 {
367 	unsigned int timeout;
368 	int ret;
369 
370 	mutex_lock(&vadc->lock);
371 
372 	ret = vadc_configure(vadc, prop);
373 	if (ret)
374 		goto unlock;
375 
376 	if (!vadc->poll_eoc)
377 		reinit_completion(&vadc->complete);
378 
379 	ret = vadc_set_state(vadc, true);
380 	if (ret)
381 		goto unlock;
382 
383 	ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
384 	if (ret)
385 		goto err_disable;
386 
387 	timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
388 
389 	if (vadc->poll_eoc) {
390 		ret = vadc_poll_wait_eoc(vadc, timeout);
391 	} else {
392 		ret = wait_for_completion_timeout(&vadc->complete, timeout);
393 		if (!ret) {
394 			ret = -ETIMEDOUT;
395 			goto err_disable;
396 		}
397 
398 		/* Double check conversion status */
399 		ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US);
400 		if (ret)
401 			goto err_disable;
402 	}
403 
404 	ret = vadc_read_result(vadc, data);
405 
406 err_disable:
407 	vadc_set_state(vadc, false);
408 	if (ret)
409 		dev_err(vadc->dev, "conversion failed\n");
410 unlock:
411 	mutex_unlock(&vadc->lock);
412 	return ret;
413 }
414 
vadc_measure_ref_points(struct vadc_priv * vadc)415 static int vadc_measure_ref_points(struct vadc_priv *vadc)
416 {
417 	struct vadc_channel_prop *prop;
418 	u16 read_1, read_2;
419 	int ret;
420 
421 	vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
422 	vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
423 
424 	prop = vadc_get_channel(vadc, VADC_REF_1250MV);
425 	ret = vadc_do_conversion(vadc, prop, &read_1);
426 	if (ret)
427 		goto err;
428 
429 	/* Try with buffered 625mV channel first */
430 	prop = vadc_get_channel(vadc, VADC_SPARE1);
431 	if (!prop)
432 		prop = vadc_get_channel(vadc, VADC_REF_625MV);
433 
434 	ret = vadc_do_conversion(vadc, prop, &read_2);
435 	if (ret)
436 		goto err;
437 
438 	if (read_1 == read_2) {
439 		ret = -EINVAL;
440 		goto err;
441 	}
442 
443 	vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
444 	vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;
445 
446 	/* Ratiometric calibration */
447 	prop = vadc_get_channel(vadc, VADC_VDD_VADC);
448 	ret = vadc_do_conversion(vadc, prop, &read_1);
449 	if (ret)
450 		goto err;
451 
452 	prop = vadc_get_channel(vadc, VADC_GND_REF);
453 	ret = vadc_do_conversion(vadc, prop, &read_2);
454 	if (ret)
455 		goto err;
456 
457 	if (read_1 == read_2) {
458 		ret = -EINVAL;
459 		goto err;
460 	}
461 
462 	vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
463 	vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
464 err:
465 	if (ret)
466 		dev_err(vadc->dev, "measure reference points failed\n");
467 
468 	return ret;
469 }
470 
vadc_calibrate(struct vadc_priv * vadc,const struct vadc_channel_prop * prop,u16 adc_code)471 static s32 vadc_calibrate(struct vadc_priv *vadc,
472 			  const struct vadc_channel_prop *prop, u16 adc_code)
473 {
474 	const struct vadc_prescale_ratio *prescale;
475 	s64 voltage;
476 
477 	voltage = adc_code - vadc->graph[prop->calibration].gnd;
478 	voltage *= vadc->graph[prop->calibration].dx;
479 	voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
480 
481 	if (prop->calibration == VADC_CALIB_ABSOLUTE)
482 		voltage += vadc->graph[prop->calibration].dx;
483 
484 	if (voltage < 0)
485 		voltage = 0;
486 
487 	prescale = &vadc_prescale_ratios[prop->prescale];
488 
489 	voltage = voltage * prescale->den;
490 
491 	return div64_s64(voltage, prescale->num);
492 }
493 
vadc_decimation_from_dt(u32 value)494 static int vadc_decimation_from_dt(u32 value)
495 {
496 	if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
497 	    value > VADC_DECIMATION_MAX)
498 		return -EINVAL;
499 
500 	return __ffs64(value / VADC_DECIMATION_MIN);
501 }
502 
vadc_prescaling_from_dt(u32 num,u32 den)503 static int vadc_prescaling_from_dt(u32 num, u32 den)
504 {
505 	unsigned int pre;
506 
507 	for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
508 		if (vadc_prescale_ratios[pre].num == num &&
509 		    vadc_prescale_ratios[pre].den == den)
510 			break;
511 
512 	if (pre == ARRAY_SIZE(vadc_prescale_ratios))
513 		return -EINVAL;
514 
515 	return pre;
516 }
517 
vadc_hw_settle_time_from_dt(u32 value)518 static int vadc_hw_settle_time_from_dt(u32 value)
519 {
520 	if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
521 		return -EINVAL;
522 
523 	if (value <= 1000)
524 		value /= 100;
525 	else
526 		value = value / 2000 + 10;
527 
528 	return value;
529 }
530 
vadc_avg_samples_from_dt(u32 value)531 static int vadc_avg_samples_from_dt(u32 value)
532 {
533 	if (!is_power_of_2(value) || value > VADC_AVG_SAMPLES_MAX)
534 		return -EINVAL;
535 
536 	return __ffs64(value);
537 }
538 
vadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)539 static int vadc_read_raw(struct iio_dev *indio_dev,
540 			 struct iio_chan_spec const *chan, int *val, int *val2,
541 			 long mask)
542 {
543 	struct vadc_priv *vadc = iio_priv(indio_dev);
544 	struct vadc_channel_prop *prop;
545 	u16 adc_code;
546 	int ret;
547 
548 	switch (mask) {
549 	case IIO_CHAN_INFO_PROCESSED:
550 		prop = &vadc->chan_props[chan->address];
551 		ret = vadc_do_conversion(vadc, prop, &adc_code);
552 		if (ret)
553 			break;
554 
555 		*val = vadc_calibrate(vadc, prop, adc_code);
556 
557 		/* 2mV/K, return milli Celsius */
558 		*val /= 2;
559 		*val -= KELVINMIL_CELSIUSMIL;
560 		return IIO_VAL_INT;
561 	case IIO_CHAN_INFO_RAW:
562 		prop = &vadc->chan_props[chan->address];
563 		ret = vadc_do_conversion(vadc, prop, &adc_code);
564 		if (ret)
565 			break;
566 
567 		*val = vadc_calibrate(vadc, prop, adc_code);
568 		return IIO_VAL_INT;
569 	case IIO_CHAN_INFO_SCALE:
570 		*val = 0;
571 		*val2 = 1000;
572 		return IIO_VAL_INT_PLUS_MICRO;
573 	default:
574 		ret = -EINVAL;
575 		break;
576 	}
577 
578 	return ret;
579 }
580 
vadc_of_xlate(struct iio_dev * indio_dev,const struct of_phandle_args * iiospec)581 static int vadc_of_xlate(struct iio_dev *indio_dev,
582 			 const struct of_phandle_args *iiospec)
583 {
584 	struct vadc_priv *vadc = iio_priv(indio_dev);
585 	unsigned int i;
586 
587 	for (i = 0; i < vadc->nchannels; i++)
588 		if (vadc->iio_chans[i].channel == iiospec->args[0])
589 			return i;
590 
591 	return -EINVAL;
592 }
593 
594 static const struct iio_info vadc_info = {
595 	.read_raw = vadc_read_raw,
596 	.of_xlate = vadc_of_xlate,
597 	.driver_module = THIS_MODULE,
598 };
599 
600 struct vadc_channels {
601 	const char *datasheet_name;
602 	unsigned int prescale_index;
603 	enum iio_chan_type type;
604 	long info_mask;
605 };
606 
607 #define VADC_CHAN(_dname, _type, _mask, _pre)				\
608 	[VADC_##_dname] = {						\
609 		.datasheet_name = __stringify(_dname),			\
610 		.prescale_index = _pre,					\
611 		.type = _type,						\
612 		.info_mask = _mask					\
613 	},								\
614 
615 #define VADC_CHAN_TEMP(_dname, _pre)					\
616 	VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre)	\
617 
618 #define VADC_CHAN_VOLT(_dname, _pre)					\
619 	VADC_CHAN(_dname, IIO_VOLTAGE,					\
620 		  BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),	\
621 		  _pre)							\
622 
623 /*
624  * The array represents all possible ADC channels found in the supported PMICs.
625  * Every index in the array is equal to the channel number per datasheet. The
626  * gaps in the array should be treated as reserved channels.
627  */
628 static const struct vadc_channels vadc_chans[] = {
629 	VADC_CHAN_VOLT(USBIN, 4)
630 	VADC_CHAN_VOLT(DCIN, 4)
631 	VADC_CHAN_VOLT(VCHG_SNS, 3)
632 	VADC_CHAN_VOLT(SPARE1_03, 1)
633 	VADC_CHAN_VOLT(USB_ID_MV, 1)
634 	VADC_CHAN_VOLT(VCOIN, 1)
635 	VADC_CHAN_VOLT(VBAT_SNS, 1)
636 	VADC_CHAN_VOLT(VSYS, 1)
637 	VADC_CHAN_TEMP(DIE_TEMP, 0)
638 	VADC_CHAN_VOLT(REF_625MV, 0)
639 	VADC_CHAN_VOLT(REF_1250MV, 0)
640 	VADC_CHAN_VOLT(CHG_TEMP, 0)
641 	VADC_CHAN_VOLT(SPARE1, 0)
642 	VADC_CHAN_VOLT(SPARE2, 0)
643 	VADC_CHAN_VOLT(GND_REF, 0)
644 	VADC_CHAN_VOLT(VDD_VADC, 0)
645 
646 	VADC_CHAN_VOLT(P_MUX1_1_1, 0)
647 	VADC_CHAN_VOLT(P_MUX2_1_1, 0)
648 	VADC_CHAN_VOLT(P_MUX3_1_1, 0)
649 	VADC_CHAN_VOLT(P_MUX4_1_1, 0)
650 	VADC_CHAN_VOLT(P_MUX5_1_1, 0)
651 	VADC_CHAN_VOLT(P_MUX6_1_1, 0)
652 	VADC_CHAN_VOLT(P_MUX7_1_1, 0)
653 	VADC_CHAN_VOLT(P_MUX8_1_1, 0)
654 	VADC_CHAN_VOLT(P_MUX9_1_1, 0)
655 	VADC_CHAN_VOLT(P_MUX10_1_1, 0)
656 	VADC_CHAN_VOLT(P_MUX11_1_1, 0)
657 	VADC_CHAN_VOLT(P_MUX12_1_1, 0)
658 	VADC_CHAN_VOLT(P_MUX13_1_1, 0)
659 	VADC_CHAN_VOLT(P_MUX14_1_1, 0)
660 	VADC_CHAN_VOLT(P_MUX15_1_1, 0)
661 	VADC_CHAN_VOLT(P_MUX16_1_1, 0)
662 
663 	VADC_CHAN_VOLT(P_MUX1_1_3, 1)
664 	VADC_CHAN_VOLT(P_MUX2_1_3, 1)
665 	VADC_CHAN_VOLT(P_MUX3_1_3, 1)
666 	VADC_CHAN_VOLT(P_MUX4_1_3, 1)
667 	VADC_CHAN_VOLT(P_MUX5_1_3, 1)
668 	VADC_CHAN_VOLT(P_MUX6_1_3, 1)
669 	VADC_CHAN_VOLT(P_MUX7_1_3, 1)
670 	VADC_CHAN_VOLT(P_MUX8_1_3, 1)
671 	VADC_CHAN_VOLT(P_MUX9_1_3, 1)
672 	VADC_CHAN_VOLT(P_MUX10_1_3, 1)
673 	VADC_CHAN_VOLT(P_MUX11_1_3, 1)
674 	VADC_CHAN_VOLT(P_MUX12_1_3, 1)
675 	VADC_CHAN_VOLT(P_MUX13_1_3, 1)
676 	VADC_CHAN_VOLT(P_MUX14_1_3, 1)
677 	VADC_CHAN_VOLT(P_MUX15_1_3, 1)
678 	VADC_CHAN_VOLT(P_MUX16_1_3, 1)
679 
680 	VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
681 	VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
682 	VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
683 	VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
684 	VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
685 	VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
686 	VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
687 	VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
688 	VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
689 	VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
690 	VADC_CHAN_VOLT(AMUX_PU1, 0)
691 	VADC_CHAN_VOLT(AMUX_PU2, 0)
692 	VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
693 
694 	VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
695 	VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
696 	VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
697 	VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
698 	VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
699 	VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
700 	VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
701 	VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
702 	VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
703 	VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
704 	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
705 
706 	VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
707 	VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
708 	VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
709 	VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
710 	VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
711 	VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
712 	VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
713 	VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
714 	VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
715 	VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
716 	VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
717 
718 	VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
719 	VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
720 	VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
721 	VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
722 	VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
723 	VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
724 	VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
725 	VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
726 	VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
727 	VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
728 	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
729 };
730 
vadc_get_dt_channel_data(struct device * dev,struct vadc_channel_prop * prop,struct device_node * node)731 static int vadc_get_dt_channel_data(struct device *dev,
732 				    struct vadc_channel_prop *prop,
733 				    struct device_node *node)
734 {
735 	const char *name = node->name;
736 	u32 chan, value, varr[2];
737 	int ret;
738 
739 	ret = of_property_read_u32(node, "reg", &chan);
740 	if (ret) {
741 		dev_err(dev, "invalid channel number %s\n", name);
742 		return ret;
743 	}
744 
745 	if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
746 		dev_err(dev, "%s invalid channel number %d\n", name, chan);
747 		return -EINVAL;
748 	}
749 
750 	/* the channel has DT description */
751 	prop->channel = chan;
752 
753 	ret = of_property_read_u32(node, "qcom,decimation", &value);
754 	if (!ret) {
755 		ret = vadc_decimation_from_dt(value);
756 		if (ret < 0) {
757 			dev_err(dev, "%02x invalid decimation %d\n",
758 				chan, value);
759 			return ret;
760 		}
761 		prop->decimation = ret;
762 	} else {
763 		prop->decimation = VADC_DEF_DECIMATION;
764 	}
765 
766 	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
767 	if (!ret) {
768 		ret = vadc_prescaling_from_dt(varr[0], varr[1]);
769 		if (ret < 0) {
770 			dev_err(dev, "%02x invalid pre-scaling <%d %d>\n",
771 				chan, varr[0], varr[1]);
772 			return ret;
773 		}
774 		prop->prescale = ret;
775 	} else {
776 		prop->prescale = vadc_chans[prop->channel].prescale_index;
777 	}
778 
779 	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
780 	if (!ret) {
781 		ret = vadc_hw_settle_time_from_dt(value);
782 		if (ret < 0) {
783 			dev_err(dev, "%02x invalid hw-settle-time %d us\n",
784 				chan, value);
785 			return ret;
786 		}
787 		prop->hw_settle_time = ret;
788 	} else {
789 		prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
790 	}
791 
792 	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
793 	if (!ret) {
794 		ret = vadc_avg_samples_from_dt(value);
795 		if (ret < 0) {
796 			dev_err(dev, "%02x invalid avg-samples %d\n",
797 				chan, value);
798 			return ret;
799 		}
800 		prop->avg_samples = ret;
801 	} else {
802 		prop->avg_samples = VADC_DEF_AVG_SAMPLES;
803 	}
804 
805 	if (of_property_read_bool(node, "qcom,ratiometric"))
806 		prop->calibration = VADC_CALIB_RATIOMETRIC;
807 	else
808 		prop->calibration = VADC_CALIB_ABSOLUTE;
809 
810 	dev_dbg(dev, "%02x name %s\n", chan, name);
811 
812 	return 0;
813 }
814 
vadc_get_dt_data(struct vadc_priv * vadc,struct device_node * node)815 static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
816 {
817 	const struct vadc_channels *vadc_chan;
818 	struct iio_chan_spec *iio_chan;
819 	struct vadc_channel_prop prop;
820 	struct device_node *child;
821 	unsigned int index = 0;
822 	int ret;
823 
824 	vadc->nchannels = of_get_available_child_count(node);
825 	if (!vadc->nchannels)
826 		return -EINVAL;
827 
828 	vadc->iio_chans = devm_kcalloc(vadc->dev, vadc->nchannels,
829 				       sizeof(*vadc->iio_chans), GFP_KERNEL);
830 	if (!vadc->iio_chans)
831 		return -ENOMEM;
832 
833 	vadc->chan_props = devm_kcalloc(vadc->dev, vadc->nchannels,
834 					sizeof(*vadc->chan_props), GFP_KERNEL);
835 	if (!vadc->chan_props)
836 		return -ENOMEM;
837 
838 	iio_chan = vadc->iio_chans;
839 
840 	for_each_available_child_of_node(node, child) {
841 		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
842 		if (ret) {
843 			of_node_put(child);
844 			return ret;
845 		}
846 
847 		vadc->chan_props[index] = prop;
848 
849 		vadc_chan = &vadc_chans[prop.channel];
850 
851 		iio_chan->channel = prop.channel;
852 		iio_chan->datasheet_name = vadc_chan->datasheet_name;
853 		iio_chan->info_mask_separate = vadc_chan->info_mask;
854 		iio_chan->type = vadc_chan->type;
855 		iio_chan->indexed = 1;
856 		iio_chan->address = index++;
857 
858 		iio_chan++;
859 	}
860 
861 	/* These channels are mandatory, they are used as reference points */
862 	if (!vadc_get_channel(vadc, VADC_REF_1250MV)) {
863 		dev_err(vadc->dev, "Please define 1.25V channel\n");
864 		return -ENODEV;
865 	}
866 
867 	if (!vadc_get_channel(vadc, VADC_REF_625MV)) {
868 		dev_err(vadc->dev, "Please define 0.625V channel\n");
869 		return -ENODEV;
870 	}
871 
872 	if (!vadc_get_channel(vadc, VADC_VDD_VADC)) {
873 		dev_err(vadc->dev, "Please define VDD channel\n");
874 		return -ENODEV;
875 	}
876 
877 	if (!vadc_get_channel(vadc, VADC_GND_REF)) {
878 		dev_err(vadc->dev, "Please define GND channel\n");
879 		return -ENODEV;
880 	}
881 
882 	return 0;
883 }
884 
vadc_isr(int irq,void * dev_id)885 static irqreturn_t vadc_isr(int irq, void *dev_id)
886 {
887 	struct vadc_priv *vadc = dev_id;
888 
889 	complete(&vadc->complete);
890 
891 	return IRQ_HANDLED;
892 }
893 
vadc_check_revision(struct vadc_priv * vadc)894 static int vadc_check_revision(struct vadc_priv *vadc)
895 {
896 	u8 val;
897 	int ret;
898 
899 	ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
900 	if (ret)
901 		return ret;
902 
903 	if (val < VADC_PERPH_TYPE_ADC) {
904 		dev_err(vadc->dev, "%d is not ADC\n", val);
905 		return -ENODEV;
906 	}
907 
908 	ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
909 	if (ret)
910 		return ret;
911 
912 	if (val < VADC_PERPH_SUBTYPE_VADC) {
913 		dev_err(vadc->dev, "%d is not VADC\n", val);
914 		return -ENODEV;
915 	}
916 
917 	ret = vadc_read(vadc, VADC_REVISION2, &val);
918 	if (ret)
919 		return ret;
920 
921 	if (val < VADC_REVISION2_SUPPORTED_VADC) {
922 		dev_err(vadc->dev, "revision %d not supported\n", val);
923 		return -ENODEV;
924 	}
925 
926 	return 0;
927 }
928 
vadc_probe(struct platform_device * pdev)929 static int vadc_probe(struct platform_device *pdev)
930 {
931 	struct device_node *node = pdev->dev.of_node;
932 	struct device *dev = &pdev->dev;
933 	struct iio_dev *indio_dev;
934 	struct vadc_priv *vadc;
935 	struct regmap *regmap;
936 	int ret, irq_eoc;
937 	u32 reg;
938 
939 	regmap = dev_get_regmap(dev->parent, NULL);
940 	if (!regmap)
941 		return -ENODEV;
942 
943 	ret = of_property_read_u32(node, "reg", &reg);
944 	if (ret < 0)
945 		return ret;
946 
947 	indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
948 	if (!indio_dev)
949 		return -ENOMEM;
950 
951 	vadc = iio_priv(indio_dev);
952 	vadc->regmap = regmap;
953 	vadc->dev = dev;
954 	vadc->base = reg;
955 	vadc->are_ref_measured = false;
956 	init_completion(&vadc->complete);
957 	mutex_init(&vadc->lock);
958 
959 	ret = vadc_check_revision(vadc);
960 	if (ret)
961 		return ret;
962 
963 	ret = vadc_get_dt_data(vadc, node);
964 	if (ret)
965 		return ret;
966 
967 	irq_eoc = platform_get_irq(pdev, 0);
968 	if (irq_eoc < 0) {
969 		if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
970 			return irq_eoc;
971 		vadc->poll_eoc = true;
972 	} else {
973 		ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
974 				       "spmi-vadc", vadc);
975 		if (ret)
976 			return ret;
977 	}
978 
979 	ret = vadc_reset(vadc);
980 	if (ret) {
981 		dev_err(dev, "reset failed\n");
982 		return ret;
983 	}
984 
985 	ret = vadc_measure_ref_points(vadc);
986 	if (ret)
987 		return ret;
988 
989 	indio_dev->dev.parent = dev;
990 	indio_dev->dev.of_node = node;
991 	indio_dev->name = pdev->name;
992 	indio_dev->modes = INDIO_DIRECT_MODE;
993 	indio_dev->info = &vadc_info;
994 	indio_dev->channels = vadc->iio_chans;
995 	indio_dev->num_channels = vadc->nchannels;
996 
997 	return devm_iio_device_register(dev, indio_dev);
998 }
999 
1000 static const struct of_device_id vadc_match_table[] = {
1001 	{ .compatible = "qcom,spmi-vadc" },
1002 	{ }
1003 };
1004 MODULE_DEVICE_TABLE(of, vadc_match_table);
1005 
1006 static struct platform_driver vadc_driver = {
1007 	.driver = {
1008 		   .name = "qcom-spmi-vadc",
1009 		   .of_match_table = vadc_match_table,
1010 	},
1011 	.probe = vadc_probe,
1012 };
1013 module_platform_driver(vadc_driver);
1014 
1015 MODULE_ALIAS("platform:qcom-spmi-vadc");
1016 MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
1017 MODULE_LICENSE("GPL v2");
1018 MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
1019 MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");
1020