xref: /openbmc/linux/drivers/iio/health/afe4404.c (revision 7e9f2839)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AFE4404 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/i2c.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/regmap.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 "afe440x.h"
27 
28 #define AFE4404_DRIVER_NAME		"afe4404"
29 
30 /* AFE4404 registers */
31 #define AFE4404_TIA_GAIN_SEP		0x20
32 #define AFE4404_TIA_GAIN		0x21
33 #define AFE4404_PROG_TG_STC		0x34
34 #define AFE4404_PROG_TG_ENDC		0x35
35 #define AFE4404_LED3LEDSTC		0x36
36 #define AFE4404_LED3LEDENDC		0x37
37 #define AFE4404_CLKDIV_PRF		0x39
38 #define AFE4404_OFFDAC			0x3a
39 #define AFE4404_DEC			0x3d
40 #define AFE4404_AVG_LED2_ALED2VAL	0x3f
41 #define AFE4404_AVG_LED1_ALED1VAL	0x40
42 
43 /* AFE4404 CONTROL2 register fields */
44 #define AFE440X_CONTROL2_OSC_ENABLE	BIT(9)
45 
46 enum afe4404_fields {
47 	/* Gains */
48 	F_TIA_GAIN_SEP, F_TIA_CF_SEP,
49 	F_TIA_GAIN, TIA_CF,
50 
51 	/* LED Current */
52 	F_ILED1, F_ILED2, F_ILED3,
53 
54 	/* Offset DAC */
55 	F_OFFDAC_AMB2, F_OFFDAC_LED1, F_OFFDAC_AMB1, F_OFFDAC_LED2,
56 
57 	/* sentinel */
58 	F_MAX_FIELDS
59 };
60 
61 static const struct reg_field afe4404_reg_fields[] = {
62 	/* Gains */
63 	[F_TIA_GAIN_SEP]	= REG_FIELD(AFE4404_TIA_GAIN_SEP, 0, 2),
64 	[F_TIA_CF_SEP]		= REG_FIELD(AFE4404_TIA_GAIN_SEP, 3, 5),
65 	[F_TIA_GAIN]		= REG_FIELD(AFE4404_TIA_GAIN, 0, 2),
66 	[TIA_CF]		= REG_FIELD(AFE4404_TIA_GAIN, 3, 5),
67 	/* LED Current */
68 	[F_ILED1]		= REG_FIELD(AFE440X_LEDCNTRL, 0, 5),
69 	[F_ILED2]		= REG_FIELD(AFE440X_LEDCNTRL, 6, 11),
70 	[F_ILED3]		= REG_FIELD(AFE440X_LEDCNTRL, 12, 17),
71 	/* Offset DAC */
72 	[F_OFFDAC_AMB2]		= REG_FIELD(AFE4404_OFFDAC, 0, 4),
73 	[F_OFFDAC_LED1]		= REG_FIELD(AFE4404_OFFDAC, 5, 9),
74 	[F_OFFDAC_AMB1]		= REG_FIELD(AFE4404_OFFDAC, 10, 14),
75 	[F_OFFDAC_LED2]		= REG_FIELD(AFE4404_OFFDAC, 15, 19),
76 };
77 
78 /**
79  * struct afe4404_data - AFE4404 device instance data
80  * @dev: Device structure
81  * @regmap: Register map of the device
82  * @fields: Register fields of the device
83  * @regulator: Pointer to the regulator for the IC
84  * @trig: IIO trigger for this device
85  * @irq: ADC_RDY line interrupt number
86  * @buffer: Used to construct a scan to push to the iio buffer.
87  */
88 struct afe4404_data {
89 	struct device *dev;
90 	struct regmap *regmap;
91 	struct regmap_field *fields[F_MAX_FIELDS];
92 	struct regulator *regulator;
93 	struct iio_trigger *trig;
94 	int irq;
95 	s32 buffer[10] __aligned(8);
96 };
97 
98 enum afe4404_chan_id {
99 	LED2 = 1,
100 	ALED2,
101 	LED1,
102 	ALED1,
103 	LED2_ALED2,
104 	LED1_ALED1,
105 };
106 
107 static const unsigned int afe4404_channel_values[] = {
108 	[LED2] = AFE440X_LED2VAL,
109 	[ALED2] = AFE440X_ALED2VAL,
110 	[LED1] = AFE440X_LED1VAL,
111 	[ALED1] = AFE440X_ALED1VAL,
112 	[LED2_ALED2] = AFE440X_LED2_ALED2VAL,
113 	[LED1_ALED1] = AFE440X_LED1_ALED1VAL,
114 };
115 
116 static const unsigned int afe4404_channel_leds[] = {
117 	[LED2] = F_ILED2,
118 	[ALED2] = F_ILED3,
119 	[LED1] = F_ILED1,
120 };
121 
122 static const unsigned int afe4404_channel_offdacs[] = {
123 	[LED2] = F_OFFDAC_LED2,
124 	[ALED2] = F_OFFDAC_AMB2,
125 	[LED1] = F_OFFDAC_LED1,
126 	[ALED1] = F_OFFDAC_AMB1,
127 };
128 
129 static const struct iio_chan_spec afe4404_channels[] = {
130 	/* ADC values */
131 	AFE440X_INTENSITY_CHAN(LED2, BIT(IIO_CHAN_INFO_OFFSET)),
132 	AFE440X_INTENSITY_CHAN(ALED2, BIT(IIO_CHAN_INFO_OFFSET)),
133 	AFE440X_INTENSITY_CHAN(LED1, BIT(IIO_CHAN_INFO_OFFSET)),
134 	AFE440X_INTENSITY_CHAN(ALED1, BIT(IIO_CHAN_INFO_OFFSET)),
135 	AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
136 	AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
137 	/* LED current */
138 	AFE440X_CURRENT_CHAN(LED2),
139 	AFE440X_CURRENT_CHAN(ALED2),
140 	AFE440X_CURRENT_CHAN(LED1),
141 };
142 
143 static const struct afe440x_val_table afe4404_res_table[] = {
144 	{ .integer = 500000, .fract = 0 },
145 	{ .integer = 250000, .fract = 0 },
146 	{ .integer = 100000, .fract = 0 },
147 	{ .integer = 50000, .fract = 0 },
148 	{ .integer = 25000, .fract = 0 },
149 	{ .integer = 10000, .fract = 0 },
150 	{ .integer = 1000000, .fract = 0 },
151 	{ .integer = 2000000, .fract = 0 },
152 };
153 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4404_res_table);
154 
155 static const struct afe440x_val_table afe4404_cap_table[] = {
156 	{ .integer = 0, .fract = 5000 },
157 	{ .integer = 0, .fract = 2500 },
158 	{ .integer = 0, .fract = 10000 },
159 	{ .integer = 0, .fract = 7500 },
160 	{ .integer = 0, .fract = 20000 },
161 	{ .integer = 0, .fract = 17500 },
162 	{ .integer = 0, .fract = 25000 },
163 	{ .integer = 0, .fract = 22500 },
164 };
165 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4404_cap_table);
166 
167 static ssize_t afe440x_show_register(struct device *dev,
168 				     struct device_attribute *attr,
169 				     char *buf)
170 {
171 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
172 	struct afe4404_data *afe = iio_priv(indio_dev);
173 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
174 	unsigned int reg_val;
175 	int vals[2];
176 	int ret;
177 
178 	ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
179 	if (ret)
180 		return ret;
181 
182 	if (reg_val >= afe440x_attr->table_size)
183 		return -EINVAL;
184 
185 	vals[0] = afe440x_attr->val_table[reg_val].integer;
186 	vals[1] = afe440x_attr->val_table[reg_val].fract;
187 
188 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
189 }
190 
191 static ssize_t afe440x_store_register(struct device *dev,
192 				      struct device_attribute *attr,
193 				      const char *buf, size_t count)
194 {
195 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
196 	struct afe4404_data *afe = iio_priv(indio_dev);
197 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
198 	int val, integer, fract, ret;
199 
200 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
201 	if (ret)
202 		return ret;
203 
204 	for (val = 0; val < afe440x_attr->table_size; val++)
205 		if (afe440x_attr->val_table[val].integer == integer &&
206 		    afe440x_attr->val_table[val].fract == fract)
207 			break;
208 	if (val == afe440x_attr->table_size)
209 		return -EINVAL;
210 
211 	ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
212 	if (ret)
213 		return ret;
214 
215 	return count;
216 }
217 
218 static AFE440X_ATTR(in_intensity1_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
219 static AFE440X_ATTR(in_intensity1_capacitance, F_TIA_CF_SEP, afe4404_cap_table);
220 
221 static AFE440X_ATTR(in_intensity2_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
222 static AFE440X_ATTR(in_intensity2_capacitance, F_TIA_CF_SEP, afe4404_cap_table);
223 
224 static AFE440X_ATTR(in_intensity3_resistance, F_TIA_GAIN, afe4404_res_table);
225 static AFE440X_ATTR(in_intensity3_capacitance, TIA_CF, afe4404_cap_table);
226 
227 static AFE440X_ATTR(in_intensity4_resistance, F_TIA_GAIN, afe4404_res_table);
228 static AFE440X_ATTR(in_intensity4_capacitance, TIA_CF, afe4404_cap_table);
229 
230 static struct attribute *afe440x_attributes[] = {
231 	&dev_attr_in_intensity_resistance_available.attr,
232 	&dev_attr_in_intensity_capacitance_available.attr,
233 	&afe440x_attr_in_intensity1_resistance.dev_attr.attr,
234 	&afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
235 	&afe440x_attr_in_intensity2_resistance.dev_attr.attr,
236 	&afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
237 	&afe440x_attr_in_intensity3_resistance.dev_attr.attr,
238 	&afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
239 	&afe440x_attr_in_intensity4_resistance.dev_attr.attr,
240 	&afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
241 	NULL
242 };
243 
244 static const struct attribute_group afe440x_attribute_group = {
245 	.attrs = afe440x_attributes
246 };
247 
248 static int afe4404_read_raw(struct iio_dev *indio_dev,
249 			    struct iio_chan_spec const *chan,
250 			    int *val, int *val2, long mask)
251 {
252 	struct afe4404_data *afe = iio_priv(indio_dev);
253 	unsigned int value_reg, led_field, offdac_field;
254 	int ret;
255 
256 	switch (chan->type) {
257 	case IIO_INTENSITY:
258 		switch (mask) {
259 		case IIO_CHAN_INFO_RAW:
260 			value_reg = afe4404_channel_values[chan->address];
261 			ret = regmap_read(afe->regmap, value_reg, val);
262 			if (ret)
263 				return ret;
264 			return IIO_VAL_INT;
265 		case IIO_CHAN_INFO_OFFSET:
266 			offdac_field = afe4404_channel_offdacs[chan->address];
267 			ret = regmap_field_read(afe->fields[offdac_field], val);
268 			if (ret)
269 				return ret;
270 			return IIO_VAL_INT;
271 		}
272 		break;
273 	case IIO_CURRENT:
274 		switch (mask) {
275 		case IIO_CHAN_INFO_RAW:
276 			led_field = afe4404_channel_leds[chan->address];
277 			ret = regmap_field_read(afe->fields[led_field], val);
278 			if (ret)
279 				return ret;
280 			return IIO_VAL_INT;
281 		case IIO_CHAN_INFO_SCALE:
282 			*val = 0;
283 			*val2 = 800000;
284 			return IIO_VAL_INT_PLUS_MICRO;
285 		}
286 		break;
287 	default:
288 		break;
289 	}
290 
291 	return -EINVAL;
292 }
293 
294 static int afe4404_write_raw(struct iio_dev *indio_dev,
295 			     struct iio_chan_spec const *chan,
296 			     int val, int val2, long mask)
297 {
298 	struct afe4404_data *afe = iio_priv(indio_dev);
299 	unsigned int led_field, offdac_field;
300 
301 	switch (chan->type) {
302 	case IIO_INTENSITY:
303 		switch (mask) {
304 		case IIO_CHAN_INFO_OFFSET:
305 			offdac_field = afe4404_channel_offdacs[chan->address];
306 			return regmap_field_write(afe->fields[offdac_field], val);
307 		}
308 		break;
309 	case IIO_CURRENT:
310 		switch (mask) {
311 		case IIO_CHAN_INFO_RAW:
312 			led_field = afe4404_channel_leds[chan->address];
313 			return regmap_field_write(afe->fields[led_field], val);
314 		}
315 		break;
316 	default:
317 		break;
318 	}
319 
320 	return -EINVAL;
321 }
322 
323 static const struct iio_info afe4404_iio_info = {
324 	.attrs = &afe440x_attribute_group,
325 	.read_raw = afe4404_read_raw,
326 	.write_raw = afe4404_write_raw,
327 };
328 
329 static irqreturn_t afe4404_trigger_handler(int irq, void *private)
330 {
331 	struct iio_poll_func *pf = private;
332 	struct iio_dev *indio_dev = pf->indio_dev;
333 	struct afe4404_data *afe = iio_priv(indio_dev);
334 	int ret, bit, i = 0;
335 
336 	for_each_set_bit(bit, indio_dev->active_scan_mask,
337 			 indio_dev->masklength) {
338 		ret = regmap_read(afe->regmap, afe4404_channel_values[bit],
339 				  &afe->buffer[i++]);
340 		if (ret)
341 			goto err;
342 	}
343 
344 	iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
345 					   pf->timestamp);
346 err:
347 	iio_trigger_notify_done(indio_dev->trig);
348 
349 	return IRQ_HANDLED;
350 }
351 
352 /* Default timings from data-sheet */
353 #define AFE4404_TIMING_PAIRS			\
354 	{ AFE440X_PRPCOUNT,	39999	},	\
355 	{ AFE440X_LED2LEDSTC,	0	},	\
356 	{ AFE440X_LED2LEDENDC,	398	},	\
357 	{ AFE440X_LED2STC,	80	},	\
358 	{ AFE440X_LED2ENDC,	398	},	\
359 	{ AFE440X_ADCRSTSTCT0,	5600	},	\
360 	{ AFE440X_ADCRSTENDCT0,	5606	},	\
361 	{ AFE440X_LED2CONVST,	5607	},	\
362 	{ AFE440X_LED2CONVEND,	6066	},	\
363 	{ AFE4404_LED3LEDSTC,	400	},	\
364 	{ AFE4404_LED3LEDENDC,	798	},	\
365 	{ AFE440X_ALED2STC,	480	},	\
366 	{ AFE440X_ALED2ENDC,	798	},	\
367 	{ AFE440X_ADCRSTSTCT1,	6068	},	\
368 	{ AFE440X_ADCRSTENDCT1,	6074	},	\
369 	{ AFE440X_ALED2CONVST,	6075	},	\
370 	{ AFE440X_ALED2CONVEND,	6534	},	\
371 	{ AFE440X_LED1LEDSTC,	800	},	\
372 	{ AFE440X_LED1LEDENDC,	1198	},	\
373 	{ AFE440X_LED1STC,	880	},	\
374 	{ AFE440X_LED1ENDC,	1198	},	\
375 	{ AFE440X_ADCRSTSTCT2,	6536	},	\
376 	{ AFE440X_ADCRSTENDCT2,	6542	},	\
377 	{ AFE440X_LED1CONVST,	6543	},	\
378 	{ AFE440X_LED1CONVEND,	7003	},	\
379 	{ AFE440X_ALED1STC,	1280	},	\
380 	{ AFE440X_ALED1ENDC,	1598	},	\
381 	{ AFE440X_ADCRSTSTCT3,	7005	},	\
382 	{ AFE440X_ADCRSTENDCT3,	7011	},	\
383 	{ AFE440X_ALED1CONVST,	7012	},	\
384 	{ AFE440X_ALED1CONVEND,	7471	},	\
385 	{ AFE440X_PDNCYCLESTC,	7671	},	\
386 	{ AFE440X_PDNCYCLEENDC,	39199	}
387 
388 static const struct reg_sequence afe4404_reg_sequences[] = {
389 	AFE4404_TIMING_PAIRS,
390 	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
391 	{ AFE4404_TIA_GAIN_SEP, AFE440X_TIAGAIN_ENSEPGAIN },
392 	{ AFE440X_CONTROL2, AFE440X_CONTROL2_OSC_ENABLE	},
393 };
394 
395 static const struct regmap_range afe4404_yes_ranges[] = {
396 	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
397 	regmap_reg_range(AFE4404_AVG_LED2_ALED2VAL, AFE4404_AVG_LED1_ALED1VAL),
398 };
399 
400 static const struct regmap_access_table afe4404_volatile_table = {
401 	.yes_ranges = afe4404_yes_ranges,
402 	.n_yes_ranges = ARRAY_SIZE(afe4404_yes_ranges),
403 };
404 
405 static const struct regmap_config afe4404_regmap_config = {
406 	.reg_bits = 8,
407 	.val_bits = 24,
408 
409 	.max_register = AFE4404_AVG_LED1_ALED1VAL,
410 	.cache_type = REGCACHE_RBTREE,
411 	.volatile_table = &afe4404_volatile_table,
412 };
413 
414 static const struct of_device_id afe4404_of_match[] = {
415 	{ .compatible = "ti,afe4404", },
416 	{ /* sentinel */ }
417 };
418 MODULE_DEVICE_TABLE(of, afe4404_of_match);
419 
420 static int afe4404_suspend(struct device *dev)
421 {
422 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
423 	struct afe4404_data *afe = iio_priv(indio_dev);
424 	int ret;
425 
426 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
427 				 AFE440X_CONTROL2_PDN_AFE,
428 				 AFE440X_CONTROL2_PDN_AFE);
429 	if (ret)
430 		return ret;
431 
432 	ret = regulator_disable(afe->regulator);
433 	if (ret) {
434 		dev_err(dev, "Unable to disable regulator\n");
435 		return ret;
436 	}
437 
438 	return 0;
439 }
440 
441 static int afe4404_resume(struct device *dev)
442 {
443 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
444 	struct afe4404_data *afe = iio_priv(indio_dev);
445 	int ret;
446 
447 	ret = regulator_enable(afe->regulator);
448 	if (ret) {
449 		dev_err(dev, "Unable to enable regulator\n");
450 		return ret;
451 	}
452 
453 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
454 				 AFE440X_CONTROL2_PDN_AFE, 0);
455 	if (ret)
456 		return ret;
457 
458 	return 0;
459 }
460 
461 static DEFINE_SIMPLE_DEV_PM_OPS(afe4404_pm_ops, afe4404_suspend,
462 				afe4404_resume);
463 
464 static int afe4404_probe(struct i2c_client *client)
465 {
466 	struct iio_dev *indio_dev;
467 	struct afe4404_data *afe;
468 	int i, ret;
469 
470 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*afe));
471 	if (!indio_dev)
472 		return -ENOMEM;
473 
474 	afe = iio_priv(indio_dev);
475 	i2c_set_clientdata(client, indio_dev);
476 
477 	afe->dev = &client->dev;
478 	afe->irq = client->irq;
479 
480 	afe->regmap = devm_regmap_init_i2c(client, &afe4404_regmap_config);
481 	if (IS_ERR(afe->regmap)) {
482 		dev_err(afe->dev, "Unable to allocate register map\n");
483 		return PTR_ERR(afe->regmap);
484 	}
485 
486 	for (i = 0; i < F_MAX_FIELDS; i++) {
487 		afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
488 							 afe4404_reg_fields[i]);
489 		if (IS_ERR(afe->fields[i])) {
490 			dev_err(afe->dev, "Unable to allocate regmap fields\n");
491 			return PTR_ERR(afe->fields[i]);
492 		}
493 	}
494 
495 	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
496 	if (IS_ERR(afe->regulator))
497 		return dev_err_probe(afe->dev, PTR_ERR(afe->regulator),
498 				     "Unable to get regulator\n");
499 
500 	ret = regulator_enable(afe->regulator);
501 	if (ret) {
502 		dev_err(afe->dev, "Unable to enable regulator\n");
503 		return ret;
504 	}
505 
506 	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
507 			   AFE440X_CONTROL0_SW_RESET);
508 	if (ret) {
509 		dev_err(afe->dev, "Unable to reset device\n");
510 		goto disable_reg;
511 	}
512 
513 	ret = regmap_multi_reg_write(afe->regmap, afe4404_reg_sequences,
514 				     ARRAY_SIZE(afe4404_reg_sequences));
515 	if (ret) {
516 		dev_err(afe->dev, "Unable to set register defaults\n");
517 		goto disable_reg;
518 	}
519 
520 	indio_dev->modes = INDIO_DIRECT_MODE;
521 	indio_dev->channels = afe4404_channels;
522 	indio_dev->num_channels = ARRAY_SIZE(afe4404_channels);
523 	indio_dev->name = AFE4404_DRIVER_NAME;
524 	indio_dev->info = &afe4404_iio_info;
525 
526 	if (afe->irq > 0) {
527 		afe->trig = devm_iio_trigger_alloc(afe->dev,
528 						   "%s-dev%d",
529 						   indio_dev->name,
530 						   iio_device_id(indio_dev));
531 		if (!afe->trig) {
532 			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
533 			ret = -ENOMEM;
534 			goto disable_reg;
535 		}
536 
537 		iio_trigger_set_drvdata(afe->trig, indio_dev);
538 
539 		ret = iio_trigger_register(afe->trig);
540 		if (ret) {
541 			dev_err(afe->dev, "Unable to register IIO trigger\n");
542 			goto disable_reg;
543 		}
544 
545 		ret = devm_request_threaded_irq(afe->dev, afe->irq,
546 						iio_trigger_generic_data_rdy_poll,
547 						NULL, IRQF_ONESHOT,
548 						AFE4404_DRIVER_NAME,
549 						afe->trig);
550 		if (ret) {
551 			dev_err(afe->dev, "Unable to request IRQ\n");
552 			goto disable_reg;
553 		}
554 	}
555 
556 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
557 					 afe4404_trigger_handler, NULL);
558 	if (ret) {
559 		dev_err(afe->dev, "Unable to setup buffer\n");
560 		goto unregister_trigger;
561 	}
562 
563 	ret = iio_device_register(indio_dev);
564 	if (ret) {
565 		dev_err(afe->dev, "Unable to register IIO device\n");
566 		goto unregister_triggered_buffer;
567 	}
568 
569 	return 0;
570 
571 unregister_triggered_buffer:
572 	iio_triggered_buffer_cleanup(indio_dev);
573 unregister_trigger:
574 	if (afe->irq > 0)
575 		iio_trigger_unregister(afe->trig);
576 disable_reg:
577 	regulator_disable(afe->regulator);
578 
579 	return ret;
580 }
581 
582 static void afe4404_remove(struct i2c_client *client)
583 {
584 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
585 	struct afe4404_data *afe = iio_priv(indio_dev);
586 	int ret;
587 
588 	iio_device_unregister(indio_dev);
589 
590 	iio_triggered_buffer_cleanup(indio_dev);
591 
592 	if (afe->irq > 0)
593 		iio_trigger_unregister(afe->trig);
594 
595 	ret = regulator_disable(afe->regulator);
596 	if (ret)
597 		dev_err(afe->dev, "Unable to disable regulator\n");
598 }
599 
600 static const struct i2c_device_id afe4404_ids[] = {
601 	{ "afe4404", 0 },
602 	{ /* sentinel */ }
603 };
604 MODULE_DEVICE_TABLE(i2c, afe4404_ids);
605 
606 static struct i2c_driver afe4404_i2c_driver = {
607 	.driver = {
608 		.name = AFE4404_DRIVER_NAME,
609 		.of_match_table = afe4404_of_match,
610 		.pm = pm_sleep_ptr(&afe4404_pm_ops),
611 	},
612 	.probe = afe4404_probe,
613 	.remove = afe4404_remove,
614 	.id_table = afe4404_ids,
615 };
616 module_i2c_driver(afe4404_i2c_driver);
617 
618 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
619 MODULE_DESCRIPTION("TI AFE4404 Heart Rate Monitor and Pulse Oximeter AFE");
620 MODULE_LICENSE("GPL v2");
621