xref: /openbmc/linux/drivers/iio/health/afe4403.c (revision 79e790ff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AFE4403 Heart Rate Monitors and Low-Cost Pulse Oximeters
4  *
5  * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
6  *	Andrew F. Davis <afd@ti.com>
7  */
8 
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/regmap.h>
15 #include <linux/spi/spi.h>
16 #include <linux/sysfs.h>
17 #include <linux/regulator/consumer.h>
18 
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 #include <linux/iio/buffer.h>
22 #include <linux/iio/trigger.h>
23 #include <linux/iio/triggered_buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 
26 #include <asm/unaligned.h>
27 
28 #include "afe440x.h"
29 
30 #define AFE4403_DRIVER_NAME		"afe4403"
31 
32 /* AFE4403 Registers */
33 #define AFE4403_TIAGAIN			0x20
34 #define AFE4403_TIA_AMB_GAIN		0x21
35 
36 enum afe4403_fields {
37 	/* Gains */
38 	F_RF_LED1, F_CF_LED1,
39 	F_RF_LED, F_CF_LED,
40 
41 	/* LED Current */
42 	F_ILED1, F_ILED2,
43 
44 	/* sentinel */
45 	F_MAX_FIELDS
46 };
47 
48 static const struct reg_field afe4403_reg_fields[] = {
49 	/* Gains */
50 	[F_RF_LED1]	= REG_FIELD(AFE4403_TIAGAIN, 0, 2),
51 	[F_CF_LED1]	= REG_FIELD(AFE4403_TIAGAIN, 3, 7),
52 	[F_RF_LED]	= REG_FIELD(AFE4403_TIA_AMB_GAIN, 0, 2),
53 	[F_CF_LED]	= REG_FIELD(AFE4403_TIA_AMB_GAIN, 3, 7),
54 	/* LED Current */
55 	[F_ILED1]	= REG_FIELD(AFE440X_LEDCNTRL, 0, 7),
56 	[F_ILED2]	= REG_FIELD(AFE440X_LEDCNTRL, 8, 15),
57 };
58 
59 /**
60  * struct afe4403_data - AFE4403 device instance data
61  * @dev: Device structure
62  * @spi: SPI device handle
63  * @regmap: Register map of the device
64  * @fields: Register fields of the device
65  * @regulator: Pointer to the regulator for the IC
66  * @trig: IIO trigger for this device
67  * @irq: ADC_RDY line interrupt number
68  * @buffer: Used to construct data layout to push into IIO buffer.
69  */
70 struct afe4403_data {
71 	struct device *dev;
72 	struct spi_device *spi;
73 	struct regmap *regmap;
74 	struct regmap_field *fields[F_MAX_FIELDS];
75 	struct regulator *regulator;
76 	struct iio_trigger *trig;
77 	int irq;
78 	/* Ensure suitable alignment for timestamp */
79 	s32 buffer[8] __aligned(8);
80 };
81 
82 enum afe4403_chan_id {
83 	LED2 = 1,
84 	ALED2,
85 	LED1,
86 	ALED1,
87 	LED2_ALED2,
88 	LED1_ALED1,
89 };
90 
91 static const unsigned int afe4403_channel_values[] = {
92 	[LED2] = AFE440X_LED2VAL,
93 	[ALED2] = AFE440X_ALED2VAL,
94 	[LED1] = AFE440X_LED1VAL,
95 	[ALED1] = AFE440X_ALED1VAL,
96 	[LED2_ALED2] = AFE440X_LED2_ALED2VAL,
97 	[LED1_ALED1] = AFE440X_LED1_ALED1VAL,
98 };
99 
100 static const unsigned int afe4403_channel_leds[] = {
101 	[LED2] = F_ILED2,
102 	[LED1] = F_ILED1,
103 };
104 
105 static const struct iio_chan_spec afe4403_channels[] = {
106 	/* ADC values */
107 	AFE440X_INTENSITY_CHAN(LED2, 0),
108 	AFE440X_INTENSITY_CHAN(ALED2, 0),
109 	AFE440X_INTENSITY_CHAN(LED1, 0),
110 	AFE440X_INTENSITY_CHAN(ALED1, 0),
111 	AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
112 	AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
113 	/* LED current */
114 	AFE440X_CURRENT_CHAN(LED2),
115 	AFE440X_CURRENT_CHAN(LED1),
116 };
117 
118 static const struct afe440x_val_table afe4403_res_table[] = {
119 	{ 500000 }, { 250000 }, { 100000 }, { 50000 },
120 	{ 25000 }, { 10000 }, { 1000000 }, { 0 },
121 };
122 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4403_res_table);
123 
124 static const struct afe440x_val_table afe4403_cap_table[] = {
125 	{ 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
126 	{ 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
127 	{ 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
128 	{ 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
129 	{ 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
130 	{ 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
131 	{ 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
132 	{ 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
133 };
134 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4403_cap_table);
135 
136 static ssize_t afe440x_show_register(struct device *dev,
137 				     struct device_attribute *attr,
138 				     char *buf)
139 {
140 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
141 	struct afe4403_data *afe = iio_priv(indio_dev);
142 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
143 	unsigned int reg_val;
144 	int vals[2];
145 	int ret;
146 
147 	ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
148 	if (ret)
149 		return ret;
150 
151 	if (reg_val >= afe440x_attr->table_size)
152 		return -EINVAL;
153 
154 	vals[0] = afe440x_attr->val_table[reg_val].integer;
155 	vals[1] = afe440x_attr->val_table[reg_val].fract;
156 
157 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
158 }
159 
160 static ssize_t afe440x_store_register(struct device *dev,
161 				      struct device_attribute *attr,
162 				      const char *buf, size_t count)
163 {
164 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
165 	struct afe4403_data *afe = iio_priv(indio_dev);
166 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
167 	int val, integer, fract, ret;
168 
169 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
170 	if (ret)
171 		return ret;
172 
173 	for (val = 0; val < afe440x_attr->table_size; val++)
174 		if (afe440x_attr->val_table[val].integer == integer &&
175 		    afe440x_attr->val_table[val].fract == fract)
176 			break;
177 	if (val == afe440x_attr->table_size)
178 		return -EINVAL;
179 
180 	ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
181 	if (ret)
182 		return ret;
183 
184 	return count;
185 }
186 
187 static AFE440X_ATTR(in_intensity1_resistance, F_RF_LED, afe4403_res_table);
188 static AFE440X_ATTR(in_intensity1_capacitance, F_CF_LED, afe4403_cap_table);
189 
190 static AFE440X_ATTR(in_intensity2_resistance, F_RF_LED, afe4403_res_table);
191 static AFE440X_ATTR(in_intensity2_capacitance, F_CF_LED, afe4403_cap_table);
192 
193 static AFE440X_ATTR(in_intensity3_resistance, F_RF_LED1, afe4403_res_table);
194 static AFE440X_ATTR(in_intensity3_capacitance, F_CF_LED1, afe4403_cap_table);
195 
196 static AFE440X_ATTR(in_intensity4_resistance, F_RF_LED1, afe4403_res_table);
197 static AFE440X_ATTR(in_intensity4_capacitance, F_CF_LED1, afe4403_cap_table);
198 
199 static struct attribute *afe440x_attributes[] = {
200 	&dev_attr_in_intensity_resistance_available.attr,
201 	&dev_attr_in_intensity_capacitance_available.attr,
202 	&afe440x_attr_in_intensity1_resistance.dev_attr.attr,
203 	&afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
204 	&afe440x_attr_in_intensity2_resistance.dev_attr.attr,
205 	&afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
206 	&afe440x_attr_in_intensity3_resistance.dev_attr.attr,
207 	&afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
208 	&afe440x_attr_in_intensity4_resistance.dev_attr.attr,
209 	&afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
210 	NULL
211 };
212 
213 static const struct attribute_group afe440x_attribute_group = {
214 	.attrs = afe440x_attributes
215 };
216 
217 static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
218 {
219 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
220 	u8 rx[3];
221 	int ret;
222 
223 	/* Enable reading from the device */
224 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
225 	if (ret)
226 		return ret;
227 
228 	ret = spi_write_then_read(afe->spi, &reg, 1, rx, sizeof(rx));
229 	if (ret)
230 		return ret;
231 
232 	*val = get_unaligned_be24(&rx[0]);
233 
234 	/* Disable reading from the device */
235 	tx[3] = AFE440X_CONTROL0_WRITE;
236 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
237 	if (ret)
238 		return ret;
239 
240 	return 0;
241 }
242 
243 static int afe4403_read_raw(struct iio_dev *indio_dev,
244 			    struct iio_chan_spec const *chan,
245 			    int *val, int *val2, long mask)
246 {
247 	struct afe4403_data *afe = iio_priv(indio_dev);
248 	unsigned int reg = afe4403_channel_values[chan->address];
249 	unsigned int field = afe4403_channel_leds[chan->address];
250 	int ret;
251 
252 	switch (chan->type) {
253 	case IIO_INTENSITY:
254 		switch (mask) {
255 		case IIO_CHAN_INFO_RAW:
256 			ret = afe4403_read(afe, reg, val);
257 			if (ret)
258 				return ret;
259 			return IIO_VAL_INT;
260 		}
261 		break;
262 	case IIO_CURRENT:
263 		switch (mask) {
264 		case IIO_CHAN_INFO_RAW:
265 			ret = regmap_field_read(afe->fields[field], val);
266 			if (ret)
267 				return ret;
268 			return IIO_VAL_INT;
269 		case IIO_CHAN_INFO_SCALE:
270 			*val = 0;
271 			*val2 = 800000;
272 			return IIO_VAL_INT_PLUS_MICRO;
273 		}
274 		break;
275 	default:
276 		break;
277 	}
278 
279 	return -EINVAL;
280 }
281 
282 static int afe4403_write_raw(struct iio_dev *indio_dev,
283 			     struct iio_chan_spec const *chan,
284 			     int val, int val2, long mask)
285 {
286 	struct afe4403_data *afe = iio_priv(indio_dev);
287 	unsigned int field = afe4403_channel_leds[chan->address];
288 
289 	switch (chan->type) {
290 	case IIO_CURRENT:
291 		switch (mask) {
292 		case IIO_CHAN_INFO_RAW:
293 			return regmap_field_write(afe->fields[field], val);
294 		}
295 		break;
296 	default:
297 		break;
298 	}
299 
300 	return -EINVAL;
301 }
302 
303 static const struct iio_info afe4403_iio_info = {
304 	.attrs = &afe440x_attribute_group,
305 	.read_raw = afe4403_read_raw,
306 	.write_raw = afe4403_write_raw,
307 };
308 
309 static irqreturn_t afe4403_trigger_handler(int irq, void *private)
310 {
311 	struct iio_poll_func *pf = private;
312 	struct iio_dev *indio_dev = pf->indio_dev;
313 	struct afe4403_data *afe = iio_priv(indio_dev);
314 	int ret, bit, i = 0;
315 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
316 	u8 rx[3];
317 
318 	/* Enable reading from the device */
319 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
320 	if (ret)
321 		goto err;
322 
323 	for_each_set_bit(bit, indio_dev->active_scan_mask,
324 			 indio_dev->masklength) {
325 		ret = spi_write_then_read(afe->spi,
326 					  &afe4403_channel_values[bit], 1,
327 					  rx, sizeof(rx));
328 		if (ret)
329 			goto err;
330 
331 		afe->buffer[i++] = get_unaligned_be24(&rx[0]);
332 	}
333 
334 	/* Disable reading from the device */
335 	tx[3] = AFE440X_CONTROL0_WRITE;
336 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
337 	if (ret)
338 		goto err;
339 
340 	iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
341 					   pf->timestamp);
342 err:
343 	iio_trigger_notify_done(indio_dev->trig);
344 
345 	return IRQ_HANDLED;
346 }
347 
348 static const struct iio_trigger_ops afe4403_trigger_ops = {
349 };
350 
351 #define AFE4403_TIMING_PAIRS			\
352 	{ AFE440X_LED2STC,	0x000050 },	\
353 	{ AFE440X_LED2ENDC,	0x0003e7 },	\
354 	{ AFE440X_LED1LEDSTC,	0x0007d0 },	\
355 	{ AFE440X_LED1LEDENDC,	0x000bb7 },	\
356 	{ AFE440X_ALED2STC,	0x000438 },	\
357 	{ AFE440X_ALED2ENDC,	0x0007cf },	\
358 	{ AFE440X_LED1STC,	0x000820 },	\
359 	{ AFE440X_LED1ENDC,	0x000bb7 },	\
360 	{ AFE440X_LED2LEDSTC,	0x000000 },	\
361 	{ AFE440X_LED2LEDENDC,	0x0003e7 },	\
362 	{ AFE440X_ALED1STC,	0x000c08 },	\
363 	{ AFE440X_ALED1ENDC,	0x000f9f },	\
364 	{ AFE440X_LED2CONVST,	0x0003ef },	\
365 	{ AFE440X_LED2CONVEND,	0x0007cf },	\
366 	{ AFE440X_ALED2CONVST,	0x0007d7 },	\
367 	{ AFE440X_ALED2CONVEND,	0x000bb7 },	\
368 	{ AFE440X_LED1CONVST,	0x000bbf },	\
369 	{ AFE440X_LED1CONVEND,	0x009c3f },	\
370 	{ AFE440X_ALED1CONVST,	0x000fa7 },	\
371 	{ AFE440X_ALED1CONVEND,	0x001387 },	\
372 	{ AFE440X_ADCRSTSTCT0,	0x0003e8 },	\
373 	{ AFE440X_ADCRSTENDCT0,	0x0003eb },	\
374 	{ AFE440X_ADCRSTSTCT1,	0x0007d0 },	\
375 	{ AFE440X_ADCRSTENDCT1,	0x0007d3 },	\
376 	{ AFE440X_ADCRSTSTCT2,	0x000bb8 },	\
377 	{ AFE440X_ADCRSTENDCT2,	0x000bbb },	\
378 	{ AFE440X_ADCRSTSTCT3,	0x000fa0 },	\
379 	{ AFE440X_ADCRSTENDCT3,	0x000fa3 },	\
380 	{ AFE440X_PRPCOUNT,	0x009c3f },	\
381 	{ AFE440X_PDNCYCLESTC,	0x001518 },	\
382 	{ AFE440X_PDNCYCLEENDC,	0x00991f }
383 
384 static const struct reg_sequence afe4403_reg_sequences[] = {
385 	AFE4403_TIMING_PAIRS,
386 	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
387 	{ AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
388 };
389 
390 static const struct regmap_range afe4403_yes_ranges[] = {
391 	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
392 };
393 
394 static const struct regmap_access_table afe4403_volatile_table = {
395 	.yes_ranges = afe4403_yes_ranges,
396 	.n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
397 };
398 
399 static const struct regmap_config afe4403_regmap_config = {
400 	.reg_bits = 8,
401 	.val_bits = 24,
402 
403 	.max_register = AFE440X_PDNCYCLEENDC,
404 	.cache_type = REGCACHE_RBTREE,
405 	.volatile_table = &afe4403_volatile_table,
406 };
407 
408 static const struct of_device_id afe4403_of_match[] = {
409 	{ .compatible = "ti,afe4403", },
410 	{ /* sentinel */ }
411 };
412 MODULE_DEVICE_TABLE(of, afe4403_of_match);
413 
414 static int __maybe_unused afe4403_suspend(struct device *dev)
415 {
416 	struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
417 	struct afe4403_data *afe = iio_priv(indio_dev);
418 	int ret;
419 
420 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
421 				 AFE440X_CONTROL2_PDN_AFE,
422 				 AFE440X_CONTROL2_PDN_AFE);
423 	if (ret)
424 		return ret;
425 
426 	ret = regulator_disable(afe->regulator);
427 	if (ret) {
428 		dev_err(dev, "Unable to disable regulator\n");
429 		return ret;
430 	}
431 
432 	return 0;
433 }
434 
435 static int __maybe_unused afe4403_resume(struct device *dev)
436 {
437 	struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
438 	struct afe4403_data *afe = iio_priv(indio_dev);
439 	int ret;
440 
441 	ret = regulator_enable(afe->regulator);
442 	if (ret) {
443 		dev_err(dev, "Unable to enable regulator\n");
444 		return ret;
445 	}
446 
447 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
448 				 AFE440X_CONTROL2_PDN_AFE, 0);
449 	if (ret)
450 		return ret;
451 
452 	return 0;
453 }
454 
455 static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
456 
457 static int afe4403_probe(struct spi_device *spi)
458 {
459 	struct iio_dev *indio_dev;
460 	struct afe4403_data *afe;
461 	int i, ret;
462 
463 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
464 	if (!indio_dev)
465 		return -ENOMEM;
466 
467 	afe = iio_priv(indio_dev);
468 	spi_set_drvdata(spi, indio_dev);
469 
470 	afe->dev = &spi->dev;
471 	afe->spi = spi;
472 	afe->irq = spi->irq;
473 
474 	afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
475 	if (IS_ERR(afe->regmap)) {
476 		dev_err(afe->dev, "Unable to allocate register map\n");
477 		return PTR_ERR(afe->regmap);
478 	}
479 
480 	for (i = 0; i < F_MAX_FIELDS; i++) {
481 		afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
482 							 afe4403_reg_fields[i]);
483 		if (IS_ERR(afe->fields[i])) {
484 			dev_err(afe->dev, "Unable to allocate regmap fields\n");
485 			return PTR_ERR(afe->fields[i]);
486 		}
487 	}
488 
489 	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
490 	if (IS_ERR(afe->regulator)) {
491 		dev_err(afe->dev, "Unable to get regulator\n");
492 		return PTR_ERR(afe->regulator);
493 	}
494 	ret = regulator_enable(afe->regulator);
495 	if (ret) {
496 		dev_err(afe->dev, "Unable to enable regulator\n");
497 		return ret;
498 	}
499 
500 	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
501 			   AFE440X_CONTROL0_SW_RESET);
502 	if (ret) {
503 		dev_err(afe->dev, "Unable to reset device\n");
504 		goto err_disable_reg;
505 	}
506 
507 	ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
508 				     ARRAY_SIZE(afe4403_reg_sequences));
509 	if (ret) {
510 		dev_err(afe->dev, "Unable to set register defaults\n");
511 		goto err_disable_reg;
512 	}
513 
514 	indio_dev->modes = INDIO_DIRECT_MODE;
515 	indio_dev->channels = afe4403_channels;
516 	indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
517 	indio_dev->name = AFE4403_DRIVER_NAME;
518 	indio_dev->info = &afe4403_iio_info;
519 
520 	if (afe->irq > 0) {
521 		afe->trig = devm_iio_trigger_alloc(afe->dev,
522 						   "%s-dev%d",
523 						   indio_dev->name,
524 						   indio_dev->id);
525 		if (!afe->trig) {
526 			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
527 			ret = -ENOMEM;
528 			goto err_disable_reg;
529 		}
530 
531 		iio_trigger_set_drvdata(afe->trig, indio_dev);
532 
533 		afe->trig->ops = &afe4403_trigger_ops;
534 
535 		ret = iio_trigger_register(afe->trig);
536 		if (ret) {
537 			dev_err(afe->dev, "Unable to register IIO trigger\n");
538 			goto err_disable_reg;
539 		}
540 
541 		ret = devm_request_threaded_irq(afe->dev, afe->irq,
542 						iio_trigger_generic_data_rdy_poll,
543 						NULL, IRQF_ONESHOT,
544 						AFE4403_DRIVER_NAME,
545 						afe->trig);
546 		if (ret) {
547 			dev_err(afe->dev, "Unable to request IRQ\n");
548 			goto err_trig;
549 		}
550 	}
551 
552 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
553 					 afe4403_trigger_handler, NULL);
554 	if (ret) {
555 		dev_err(afe->dev, "Unable to setup buffer\n");
556 		goto err_trig;
557 	}
558 
559 	ret = iio_device_register(indio_dev);
560 	if (ret) {
561 		dev_err(afe->dev, "Unable to register IIO device\n");
562 		goto err_buff;
563 	}
564 
565 	return 0;
566 
567 err_buff:
568 	iio_triggered_buffer_cleanup(indio_dev);
569 err_trig:
570 	if (afe->irq > 0)
571 		iio_trigger_unregister(afe->trig);
572 err_disable_reg:
573 	regulator_disable(afe->regulator);
574 
575 	return ret;
576 }
577 
578 static int afe4403_remove(struct spi_device *spi)
579 {
580 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
581 	struct afe4403_data *afe = iio_priv(indio_dev);
582 	int ret;
583 
584 	iio_device_unregister(indio_dev);
585 
586 	iio_triggered_buffer_cleanup(indio_dev);
587 
588 	if (afe->irq > 0)
589 		iio_trigger_unregister(afe->trig);
590 
591 	ret = regulator_disable(afe->regulator);
592 	if (ret) {
593 		dev_err(afe->dev, "Unable to disable regulator\n");
594 		return ret;
595 	}
596 
597 	return 0;
598 }
599 
600 static const struct spi_device_id afe4403_ids[] = {
601 	{ "afe4403", 0 },
602 	{ /* sentinel */ }
603 };
604 MODULE_DEVICE_TABLE(spi, afe4403_ids);
605 
606 static struct spi_driver afe4403_spi_driver = {
607 	.driver = {
608 		.name = AFE4403_DRIVER_NAME,
609 		.of_match_table = afe4403_of_match,
610 		.pm = &afe4403_pm_ops,
611 	},
612 	.probe = afe4403_probe,
613 	.remove = afe4403_remove,
614 	.id_table = afe4403_ids,
615 };
616 module_spi_driver(afe4403_spi_driver);
617 
618 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
619 MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
620 MODULE_LICENSE("GPL v2");
621