xref: /openbmc/linux/drivers/iio/health/afe4403.c (revision b36e8257641a043764c62240316610c81e36376c)
1 /*
2  * AFE4403 Heart Rate Monitors and Low-Cost Pulse Oximeters
3  *
4  * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
5  *	Andrew F. Davis <afd@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  */
16 
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/interrupt.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/regmap.h>
23 #include <linux/spi/spi.h>
24 #include <linux/sysfs.h>
25 #include <linux/regulator/consumer.h>
26 
27 #include <linux/iio/iio.h>
28 #include <linux/iio/sysfs.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/trigger.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/iio/trigger_consumer.h>
33 
34 #include "afe440x.h"
35 
36 #define AFE4403_DRIVER_NAME		"afe4403"
37 
38 /* AFE4403 Registers */
39 #define AFE4403_TIAGAIN			0x20
40 #define AFE4403_TIA_AMB_GAIN		0x21
41 
42 /* AFE4403 LEDCNTRL values */
43 #define AFE440X_LEDCNTRL_RANGE_TX_HALF	0x1
44 #define AFE440X_LEDCNTRL_RANGE_TX_FULL	0x2
45 #define AFE440X_LEDCNTRL_RANGE_TX_OFF	0x3
46 
47 /* AFE4403 CONTROL2 values */
48 #define AFE440X_CONTROL2_TX_REF_025	0x0
49 #define AFE440X_CONTROL2_TX_REF_050	0x1
50 #define AFE440X_CONTROL2_TX_REF_100	0x2
51 #define AFE440X_CONTROL2_TX_REF_075	0x3
52 
53 /* AFE4403 CONTROL3 values */
54 #define AFE440X_CONTROL3_CLK_DIV_2	0x0
55 #define AFE440X_CONTROL3_CLK_DIV_4	0x2
56 #define AFE440X_CONTROL3_CLK_DIV_6	0x3
57 #define AFE440X_CONTROL3_CLK_DIV_8	0x4
58 #define AFE440X_CONTROL3_CLK_DIV_12	0x5
59 #define AFE440X_CONTROL3_CLK_DIV_1	0x7
60 
61 /* AFE4403 TIAGAIN_CAP values */
62 #define AFE4403_TIAGAIN_CAP_5_P		0x0
63 #define AFE4403_TIAGAIN_CAP_10_P	0x1
64 #define AFE4403_TIAGAIN_CAP_20_P	0x2
65 #define AFE4403_TIAGAIN_CAP_30_P	0x3
66 #define AFE4403_TIAGAIN_CAP_55_P	0x8
67 #define AFE4403_TIAGAIN_CAP_155_P	0x10
68 
69 /* AFE4403 TIAGAIN_RES values */
70 #define AFE4403_TIAGAIN_RES_500_K	0x0
71 #define AFE4403_TIAGAIN_RES_250_K	0x1
72 #define AFE4403_TIAGAIN_RES_100_K	0x2
73 #define AFE4403_TIAGAIN_RES_50_K	0x3
74 #define AFE4403_TIAGAIN_RES_25_K	0x4
75 #define AFE4403_TIAGAIN_RES_10_K	0x5
76 #define AFE4403_TIAGAIN_RES_1_M		0x6
77 #define AFE4403_TIAGAIN_RES_NONE	0x7
78 
79 enum afe4403_fields {
80 	/* Gains */
81 	F_RF_LED1, F_CF_LED1,
82 	F_RF_LED, F_CF_LED,
83 
84 	/* LED Current */
85 	F_ILED1, F_ILED2,
86 
87 	/* sentinel */
88 	F_MAX_FIELDS
89 };
90 
91 static const struct reg_field afe4403_reg_fields[] = {
92 	/* Gains */
93 	[F_RF_LED1]	= REG_FIELD(AFE4403_TIAGAIN, 0, 2),
94 	[F_CF_LED1]	= REG_FIELD(AFE4403_TIAGAIN, 3, 7),
95 	[F_RF_LED]	= REG_FIELD(AFE4403_TIA_AMB_GAIN, 0, 2),
96 	[F_CF_LED]	= REG_FIELD(AFE4403_TIA_AMB_GAIN, 3, 7),
97 	/* LED Current */
98 	[F_ILED1]	= REG_FIELD(AFE440X_LEDCNTRL, 0, 7),
99 	[F_ILED2]	= REG_FIELD(AFE440X_LEDCNTRL, 8, 15),
100 };
101 
102 /**
103  * struct afe4403_data - AFE4403 device instance data
104  * @dev: Device structure
105  * @spi: SPI device handle
106  * @regmap: Register map of the device
107  * @fields: Register fields of the device
108  * @regulator: Pointer to the regulator for the IC
109  * @trig: IIO trigger for this device
110  * @irq: ADC_RDY line interrupt number
111  */
112 struct afe4403_data {
113 	struct device *dev;
114 	struct spi_device *spi;
115 	struct regmap *regmap;
116 	struct regmap_field *fields[F_MAX_FIELDS];
117 	struct regulator *regulator;
118 	struct iio_trigger *trig;
119 	int irq;
120 };
121 
122 enum afe4403_chan_id {
123 	LED2 = 1,
124 	ALED2,
125 	LED1,
126 	ALED1,
127 	LED2_ALED2,
128 	LED1_ALED1,
129 	ILED1,
130 	ILED2,
131 };
132 
133 static const unsigned int afe4403_channel_values[] = {
134 	[LED2] = AFE440X_LED2VAL,
135 	[ALED2] = AFE440X_ALED2VAL,
136 	[LED1] = AFE440X_LED1VAL,
137 	[ALED1] = AFE440X_ALED1VAL,
138 	[LED2_ALED2] = AFE440X_LED2_ALED2VAL,
139 	[LED1_ALED1] = AFE440X_LED1_ALED1VAL,
140 };
141 
142 static const unsigned int afe4403_channel_leds[] = {
143 	[ILED1] = F_ILED1,
144 	[ILED2] = F_ILED2,
145 };
146 
147 static const struct iio_chan_spec afe4403_channels[] = {
148 	/* ADC values */
149 	AFE440X_INTENSITY_CHAN(LED2, 0),
150 	AFE440X_INTENSITY_CHAN(ALED2, 0),
151 	AFE440X_INTENSITY_CHAN(LED1, 0),
152 	AFE440X_INTENSITY_CHAN(ALED1, 0),
153 	AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
154 	AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
155 	/* LED current */
156 	AFE440X_CURRENT_CHAN(ILED1),
157 	AFE440X_CURRENT_CHAN(ILED2),
158 };
159 
160 static const struct afe440x_val_table afe4403_res_table[] = {
161 	{ 500000 }, { 250000 }, { 100000 }, { 50000 },
162 	{ 25000 }, { 10000 }, { 1000000 }, { 0 },
163 };
164 AFE440X_TABLE_ATTR(tia_resistance_available, afe4403_res_table);
165 
166 static const struct afe440x_val_table afe4403_cap_table[] = {
167 	{ 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
168 	{ 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
169 	{ 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
170 	{ 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
171 	{ 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
172 	{ 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
173 	{ 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
174 	{ 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
175 };
176 AFE440X_TABLE_ATTR(tia_capacitance_available, afe4403_cap_table);
177 
178 static ssize_t afe440x_show_register(struct device *dev,
179 				     struct device_attribute *attr,
180 				     char *buf)
181 {
182 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
183 	struct afe4403_data *afe = iio_priv(indio_dev);
184 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
185 	unsigned int reg_val;
186 	int vals[2];
187 	int ret;
188 
189 	ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
190 	if (ret)
191 		return ret;
192 
193 	if (reg_val >= afe440x_attr->table_size)
194 		return -EINVAL;
195 
196 	vals[0] = afe440x_attr->val_table[reg_val].integer;
197 	vals[1] = afe440x_attr->val_table[reg_val].fract;
198 
199 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
200 }
201 
202 static ssize_t afe440x_store_register(struct device *dev,
203 				      struct device_attribute *attr,
204 				      const char *buf, size_t count)
205 {
206 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
207 	struct afe4403_data *afe = iio_priv(indio_dev);
208 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
209 	int val, integer, fract, ret;
210 
211 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
212 	if (ret)
213 		return ret;
214 
215 	for (val = 0; val < afe440x_attr->table_size; val++)
216 		if (afe440x_attr->val_table[val].integer == integer &&
217 		    afe440x_attr->val_table[val].fract == fract)
218 			break;
219 	if (val == afe440x_attr->table_size)
220 		return -EINVAL;
221 
222 	ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
223 	if (ret)
224 		return ret;
225 
226 	return count;
227 }
228 
229 static AFE440X_ATTR(tia_resistance1, F_RF_LED1, afe4403_res_table);
230 static AFE440X_ATTR(tia_capacitance1, F_CF_LED1, afe4403_cap_table);
231 
232 static AFE440X_ATTR(tia_resistance2, F_RF_LED, afe4403_res_table);
233 static AFE440X_ATTR(tia_capacitance2, F_CF_LED, afe4403_cap_table);
234 
235 static struct attribute *afe440x_attributes[] = {
236 	&afe440x_attr_tia_resistance1.dev_attr.attr,
237 	&afe440x_attr_tia_capacitance1.dev_attr.attr,
238 	&afe440x_attr_tia_resistance2.dev_attr.attr,
239 	&afe440x_attr_tia_capacitance2.dev_attr.attr,
240 	&dev_attr_tia_resistance_available.attr,
241 	&dev_attr_tia_capacitance_available.attr,
242 	NULL
243 };
244 
245 static const struct attribute_group afe440x_attribute_group = {
246 	.attrs = afe440x_attributes
247 };
248 
249 static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
250 {
251 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
252 	u8 rx[3];
253 	int ret;
254 
255 	/* Enable reading from the device */
256 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
257 	if (ret)
258 		return ret;
259 
260 	ret = spi_write_then_read(afe->spi, &reg, 1, rx, 3);
261 	if (ret)
262 		return ret;
263 
264 	*val = (rx[0] << 16) |
265 		(rx[1] << 8) |
266 		(rx[2]);
267 
268 	/* Disable reading from the device */
269 	tx[3] = AFE440X_CONTROL0_WRITE;
270 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
271 	if (ret)
272 		return ret;
273 
274 	return 0;
275 }
276 
277 static int afe4403_read_raw(struct iio_dev *indio_dev,
278 			    struct iio_chan_spec const *chan,
279 			    int *val, int *val2, long mask)
280 {
281 	struct afe4403_data *afe = iio_priv(indio_dev);
282 	unsigned int reg = afe4403_channel_values[chan->address];
283 	unsigned int field = afe4403_channel_leds[chan->address];
284 	int ret;
285 
286 	switch (chan->type) {
287 	case IIO_INTENSITY:
288 		switch (mask) {
289 		case IIO_CHAN_INFO_RAW:
290 			ret = afe4403_read(afe, reg, val);
291 			if (ret)
292 				return ret;
293 			return IIO_VAL_INT;
294 		}
295 		break;
296 	case IIO_CURRENT:
297 		switch (mask) {
298 		case IIO_CHAN_INFO_RAW:
299 			ret = regmap_field_read(afe->fields[field], val);
300 			if (ret)
301 				return ret;
302 			return IIO_VAL_INT;
303 		case IIO_CHAN_INFO_SCALE:
304 			*val = 0;
305 			*val2 = 800000;
306 			return IIO_VAL_INT_PLUS_MICRO;
307 		}
308 		break;
309 	default:
310 		break;
311 	}
312 
313 	return -EINVAL;
314 }
315 
316 static int afe4403_write_raw(struct iio_dev *indio_dev,
317 			     struct iio_chan_spec const *chan,
318 			     int val, int val2, long mask)
319 {
320 	struct afe4403_data *afe = iio_priv(indio_dev);
321 	unsigned int field = afe4403_channel_leds[chan->address];
322 
323 	switch (chan->type) {
324 	case IIO_CURRENT:
325 		switch (mask) {
326 		case IIO_CHAN_INFO_RAW:
327 			return regmap_field_write(afe->fields[field], val);
328 		}
329 		break;
330 	default:
331 		break;
332 	}
333 
334 	return -EINVAL;
335 }
336 
337 static const struct iio_info afe4403_iio_info = {
338 	.attrs = &afe440x_attribute_group,
339 	.read_raw = afe4403_read_raw,
340 	.write_raw = afe4403_write_raw,
341 	.driver_module = THIS_MODULE,
342 };
343 
344 static irqreturn_t afe4403_trigger_handler(int irq, void *private)
345 {
346 	struct iio_poll_func *pf = private;
347 	struct iio_dev *indio_dev = pf->indio_dev;
348 	struct afe4403_data *afe = iio_priv(indio_dev);
349 	int ret, bit, i = 0;
350 	s32 buffer[8];
351 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
352 	u8 rx[3];
353 
354 	/* Enable reading from the device */
355 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
356 	if (ret)
357 		goto err;
358 
359 	for_each_set_bit(bit, indio_dev->active_scan_mask,
360 			 indio_dev->masklength) {
361 		ret = spi_write_then_read(afe->spi,
362 					  &afe4403_channel_values[bit], 1,
363 					  rx, 3);
364 		if (ret)
365 			goto err;
366 
367 		buffer[i++] = (rx[0] << 16) |
368 				(rx[1] << 8) |
369 				(rx[2]);
370 	}
371 
372 	/* Disable reading from the device */
373 	tx[3] = AFE440X_CONTROL0_WRITE;
374 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
375 	if (ret)
376 		goto err;
377 
378 	iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
379 err:
380 	iio_trigger_notify_done(indio_dev->trig);
381 
382 	return IRQ_HANDLED;
383 }
384 
385 static const struct iio_trigger_ops afe4403_trigger_ops = {
386 	.owner = THIS_MODULE,
387 };
388 
389 #define AFE4403_TIMING_PAIRS			\
390 	{ AFE440X_LED2STC,	0x000050 },	\
391 	{ AFE440X_LED2ENDC,	0x0003e7 },	\
392 	{ AFE440X_LED1LEDSTC,	0x0007d0 },	\
393 	{ AFE440X_LED1LEDENDC,	0x000bb7 },	\
394 	{ AFE440X_ALED2STC,	0x000438 },	\
395 	{ AFE440X_ALED2ENDC,	0x0007cf },	\
396 	{ AFE440X_LED1STC,	0x000820 },	\
397 	{ AFE440X_LED1ENDC,	0x000bb7 },	\
398 	{ AFE440X_LED2LEDSTC,	0x000000 },	\
399 	{ AFE440X_LED2LEDENDC,	0x0003e7 },	\
400 	{ AFE440X_ALED1STC,	0x000c08 },	\
401 	{ AFE440X_ALED1ENDC,	0x000f9f },	\
402 	{ AFE440X_LED2CONVST,	0x0003ef },	\
403 	{ AFE440X_LED2CONVEND,	0x0007cf },	\
404 	{ AFE440X_ALED2CONVST,	0x0007d7 },	\
405 	{ AFE440X_ALED2CONVEND,	0x000bb7 },	\
406 	{ AFE440X_LED1CONVST,	0x000bbf },	\
407 	{ AFE440X_LED1CONVEND,	0x009c3f },	\
408 	{ AFE440X_ALED1CONVST,	0x000fa7 },	\
409 	{ AFE440X_ALED1CONVEND,	0x001387 },	\
410 	{ AFE440X_ADCRSTSTCT0,	0x0003e8 },	\
411 	{ AFE440X_ADCRSTENDCT0,	0x0003eb },	\
412 	{ AFE440X_ADCRSTSTCT1,	0x0007d0 },	\
413 	{ AFE440X_ADCRSTENDCT1,	0x0007d3 },	\
414 	{ AFE440X_ADCRSTSTCT2,	0x000bb8 },	\
415 	{ AFE440X_ADCRSTENDCT2,	0x000bbb },	\
416 	{ AFE440X_ADCRSTSTCT3,	0x000fa0 },	\
417 	{ AFE440X_ADCRSTENDCT3,	0x000fa3 },	\
418 	{ AFE440X_PRPCOUNT,	0x009c3f },	\
419 	{ AFE440X_PDNCYCLESTC,	0x001518 },	\
420 	{ AFE440X_PDNCYCLEENDC,	0x00991f }
421 
422 static const struct reg_sequence afe4403_reg_sequences[] = {
423 	AFE4403_TIMING_PAIRS,
424 	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
425 	{ AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
426 };
427 
428 static const struct regmap_range afe4403_yes_ranges[] = {
429 	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
430 };
431 
432 static const struct regmap_access_table afe4403_volatile_table = {
433 	.yes_ranges = afe4403_yes_ranges,
434 	.n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
435 };
436 
437 static const struct regmap_config afe4403_regmap_config = {
438 	.reg_bits = 8,
439 	.val_bits = 24,
440 
441 	.max_register = AFE440X_PDNCYCLEENDC,
442 	.cache_type = REGCACHE_RBTREE,
443 	.volatile_table = &afe4403_volatile_table,
444 };
445 
446 static const struct of_device_id afe4403_of_match[] = {
447 	{ .compatible = "ti,afe4403", },
448 	{ /* sentinel */ }
449 };
450 MODULE_DEVICE_TABLE(of, afe4403_of_match);
451 
452 static int __maybe_unused afe4403_suspend(struct device *dev)
453 {
454 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
455 	struct afe4403_data *afe = iio_priv(indio_dev);
456 	int ret;
457 
458 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
459 				 AFE440X_CONTROL2_PDN_AFE,
460 				 AFE440X_CONTROL2_PDN_AFE);
461 	if (ret)
462 		return ret;
463 
464 	ret = regulator_disable(afe->regulator);
465 	if (ret) {
466 		dev_err(dev, "Unable to disable regulator\n");
467 		return ret;
468 	}
469 
470 	return 0;
471 }
472 
473 static int __maybe_unused afe4403_resume(struct device *dev)
474 {
475 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
476 	struct afe4403_data *afe = iio_priv(indio_dev);
477 	int ret;
478 
479 	ret = regulator_enable(afe->regulator);
480 	if (ret) {
481 		dev_err(dev, "Unable to enable regulator\n");
482 		return ret;
483 	}
484 
485 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
486 				 AFE440X_CONTROL2_PDN_AFE, 0);
487 	if (ret)
488 		return ret;
489 
490 	return 0;
491 }
492 
493 static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
494 
495 static int afe4403_probe(struct spi_device *spi)
496 {
497 	struct iio_dev *indio_dev;
498 	struct afe4403_data *afe;
499 	int i, ret;
500 
501 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
502 	if (!indio_dev)
503 		return -ENOMEM;
504 
505 	afe = iio_priv(indio_dev);
506 	spi_set_drvdata(spi, indio_dev);
507 
508 	afe->dev = &spi->dev;
509 	afe->spi = spi;
510 	afe->irq = spi->irq;
511 
512 	afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
513 	if (IS_ERR(afe->regmap)) {
514 		dev_err(afe->dev, "Unable to allocate register map\n");
515 		return PTR_ERR(afe->regmap);
516 	}
517 
518 	for (i = 0; i < F_MAX_FIELDS; i++) {
519 		afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
520 							 afe4403_reg_fields[i]);
521 		if (IS_ERR(afe->fields[i])) {
522 			dev_err(afe->dev, "Unable to allocate regmap fields\n");
523 			return PTR_ERR(afe->fields[i]);
524 		}
525 	}
526 
527 	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
528 	if (IS_ERR(afe->regulator)) {
529 		dev_err(afe->dev, "Unable to get regulator\n");
530 		return PTR_ERR(afe->regulator);
531 	}
532 	ret = regulator_enable(afe->regulator);
533 	if (ret) {
534 		dev_err(afe->dev, "Unable to enable regulator\n");
535 		return ret;
536 	}
537 
538 	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
539 			   AFE440X_CONTROL0_SW_RESET);
540 	if (ret) {
541 		dev_err(afe->dev, "Unable to reset device\n");
542 		goto err_disable_reg;
543 	}
544 
545 	ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
546 				     ARRAY_SIZE(afe4403_reg_sequences));
547 	if (ret) {
548 		dev_err(afe->dev, "Unable to set register defaults\n");
549 		goto err_disable_reg;
550 	}
551 
552 	indio_dev->modes = INDIO_DIRECT_MODE;
553 	indio_dev->dev.parent = afe->dev;
554 	indio_dev->channels = afe4403_channels;
555 	indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
556 	indio_dev->name = AFE4403_DRIVER_NAME;
557 	indio_dev->info = &afe4403_iio_info;
558 
559 	if (afe->irq > 0) {
560 		afe->trig = devm_iio_trigger_alloc(afe->dev,
561 						   "%s-dev%d",
562 						   indio_dev->name,
563 						   indio_dev->id);
564 		if (!afe->trig) {
565 			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
566 			ret = -ENOMEM;
567 			goto err_disable_reg;
568 		}
569 
570 		iio_trigger_set_drvdata(afe->trig, indio_dev);
571 
572 		afe->trig->ops = &afe4403_trigger_ops;
573 		afe->trig->dev.parent = afe->dev;
574 
575 		ret = iio_trigger_register(afe->trig);
576 		if (ret) {
577 			dev_err(afe->dev, "Unable to register IIO trigger\n");
578 			goto err_disable_reg;
579 		}
580 
581 		ret = devm_request_threaded_irq(afe->dev, afe->irq,
582 						iio_trigger_generic_data_rdy_poll,
583 						NULL, IRQF_ONESHOT,
584 						AFE4403_DRIVER_NAME,
585 						afe->trig);
586 		if (ret) {
587 			dev_err(afe->dev, "Unable to request IRQ\n");
588 			goto err_trig;
589 		}
590 	}
591 
592 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
593 					 afe4403_trigger_handler, NULL);
594 	if (ret) {
595 		dev_err(afe->dev, "Unable to setup buffer\n");
596 		goto err_trig;
597 	}
598 
599 	ret = iio_device_register(indio_dev);
600 	if (ret) {
601 		dev_err(afe->dev, "Unable to register IIO device\n");
602 		goto err_buff;
603 	}
604 
605 	return 0;
606 
607 err_buff:
608 	iio_triggered_buffer_cleanup(indio_dev);
609 err_trig:
610 	if (afe->irq > 0)
611 		iio_trigger_unregister(afe->trig);
612 err_disable_reg:
613 	regulator_disable(afe->regulator);
614 
615 	return ret;
616 }
617 
618 static int afe4403_remove(struct spi_device *spi)
619 {
620 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
621 	struct afe4403_data *afe = iio_priv(indio_dev);
622 	int ret;
623 
624 	iio_device_unregister(indio_dev);
625 
626 	iio_triggered_buffer_cleanup(indio_dev);
627 
628 	if (afe->irq > 0)
629 		iio_trigger_unregister(afe->trig);
630 
631 	ret = regulator_disable(afe->regulator);
632 	if (ret) {
633 		dev_err(afe->dev, "Unable to disable regulator\n");
634 		return ret;
635 	}
636 
637 	return 0;
638 }
639 
640 static const struct spi_device_id afe4403_ids[] = {
641 	{ "afe4403", 0 },
642 	{ /* sentinel */ }
643 };
644 MODULE_DEVICE_TABLE(spi, afe4403_ids);
645 
646 static struct spi_driver afe4403_spi_driver = {
647 	.driver = {
648 		.name = AFE4403_DRIVER_NAME,
649 		.of_match_table = afe4403_of_match,
650 		.pm = &afe4403_pm_ops,
651 	},
652 	.probe = afe4403_probe,
653 	.remove = afe4403_remove,
654 	.id_table = afe4403_ids,
655 };
656 module_spi_driver(afe4403_spi_driver);
657 
658 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
659 MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
660 MODULE_LICENSE("GPL v2");
661