xref: /openbmc/linux/drivers/iio/health/afe4403.c (revision 2e0df3a583af9297259ff5512c1a843220492770)
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 GAIN register fields */
43 #define AFE4403_TIAGAIN_RES_MASK	GENMASK(2, 0)
44 #define AFE4403_TIAGAIN_RES_SHIFT	0
45 #define AFE4403_TIAGAIN_CAP_MASK	GENMASK(7, 3)
46 #define AFE4403_TIAGAIN_CAP_SHIFT	3
47 
48 /* AFE4403 LEDCNTRL register fields */
49 #define AFE440X_LEDCNTRL_LED1_MASK		GENMASK(15, 8)
50 #define AFE440X_LEDCNTRL_LED1_SHIFT		8
51 #define AFE440X_LEDCNTRL_LED2_MASK		GENMASK(7, 0)
52 #define AFE440X_LEDCNTRL_LED2_SHIFT		0
53 #define AFE440X_LEDCNTRL_LED_RANGE_MASK		GENMASK(17, 16)
54 #define AFE440X_LEDCNTRL_LED_RANGE_SHIFT	16
55 
56 /* AFE4403 CONTROL2 register fields */
57 #define AFE440X_CONTROL2_PWR_DWN_TX	BIT(2)
58 #define AFE440X_CONTROL2_EN_SLOW_DIAG	BIT(8)
59 #define AFE440X_CONTROL2_DIAG_OUT_TRI	BIT(10)
60 #define AFE440X_CONTROL2_TX_BRDG_MOD	BIT(11)
61 #define AFE440X_CONTROL2_TX_REF_MASK	GENMASK(18, 17)
62 #define AFE440X_CONTROL2_TX_REF_SHIFT	17
63 
64 /* AFE4404 NULL fields */
65 #define NULL_MASK	0
66 #define NULL_SHIFT	0
67 
68 /* AFE4403 LEDCNTRL values */
69 #define AFE440X_LEDCNTRL_RANGE_TX_HALF	0x1
70 #define AFE440X_LEDCNTRL_RANGE_TX_FULL	0x2
71 #define AFE440X_LEDCNTRL_RANGE_TX_OFF	0x3
72 
73 /* AFE4403 CONTROL2 values */
74 #define AFE440X_CONTROL2_TX_REF_025	0x0
75 #define AFE440X_CONTROL2_TX_REF_050	0x1
76 #define AFE440X_CONTROL2_TX_REF_100	0x2
77 #define AFE440X_CONTROL2_TX_REF_075	0x3
78 
79 /* AFE4403 CONTROL3 values */
80 #define AFE440X_CONTROL3_CLK_DIV_2	0x0
81 #define AFE440X_CONTROL3_CLK_DIV_4	0x2
82 #define AFE440X_CONTROL3_CLK_DIV_6	0x3
83 #define AFE440X_CONTROL3_CLK_DIV_8	0x4
84 #define AFE440X_CONTROL3_CLK_DIV_12	0x5
85 #define AFE440X_CONTROL3_CLK_DIV_1	0x7
86 
87 /* AFE4403 TIAGAIN_CAP values */
88 #define AFE4403_TIAGAIN_CAP_5_P		0x0
89 #define AFE4403_TIAGAIN_CAP_10_P	0x1
90 #define AFE4403_TIAGAIN_CAP_20_P	0x2
91 #define AFE4403_TIAGAIN_CAP_30_P	0x3
92 #define AFE4403_TIAGAIN_CAP_55_P	0x8
93 #define AFE4403_TIAGAIN_CAP_155_P	0x10
94 
95 /* AFE4403 TIAGAIN_RES values */
96 #define AFE4403_TIAGAIN_RES_500_K	0x0
97 #define AFE4403_TIAGAIN_RES_250_K	0x1
98 #define AFE4403_TIAGAIN_RES_100_K	0x2
99 #define AFE4403_TIAGAIN_RES_50_K	0x3
100 #define AFE4403_TIAGAIN_RES_25_K	0x4
101 #define AFE4403_TIAGAIN_RES_10_K	0x5
102 #define AFE4403_TIAGAIN_RES_1_M		0x6
103 #define AFE4403_TIAGAIN_RES_NONE	0x7
104 
105 /**
106  * struct afe4403_data - AFE4403 device instance data
107  * @dev: Device structure
108  * @spi: SPI device handle
109  * @regmap: Register map of the device
110  * @regulator: Pointer to the regulator for the IC
111  * @trig: IIO trigger for this device
112  * @irq: ADC_RDY line interrupt number
113  */
114 struct afe4403_data {
115 	struct device *dev;
116 	struct spi_device *spi;
117 	struct regmap *regmap;
118 	struct regulator *regulator;
119 	struct iio_trigger *trig;
120 	int irq;
121 };
122 
123 enum afe4403_chan_id {
124 	LED1,
125 	ALED1,
126 	LED2,
127 	ALED2,
128 	LED1_ALED1,
129 	LED2_ALED2,
130 	ILED1,
131 	ILED2,
132 };
133 
134 static const struct afe440x_reg_info afe4403_reg_info[] = {
135 	[LED1] = AFE440X_REG_INFO(AFE440X_LED1VAL, 0, NULL),
136 	[ALED1] = AFE440X_REG_INFO(AFE440X_ALED1VAL, 0, NULL),
137 	[LED2] = AFE440X_REG_INFO(AFE440X_LED2VAL, 0, NULL),
138 	[ALED2] = AFE440X_REG_INFO(AFE440X_ALED2VAL, 0, NULL),
139 	[LED1_ALED1] = AFE440X_REG_INFO(AFE440X_LED1_ALED1VAL, 0, NULL),
140 	[LED2_ALED2] = AFE440X_REG_INFO(AFE440X_LED2_ALED2VAL, 0, NULL),
141 	[ILED1] = AFE440X_REG_INFO(AFE440X_LEDCNTRL, 0, AFE440X_LEDCNTRL_LED1),
142 	[ILED2] = AFE440X_REG_INFO(AFE440X_LEDCNTRL, 0, AFE440X_LEDCNTRL_LED2),
143 };
144 
145 static const struct iio_chan_spec afe4403_channels[] = {
146 	/* ADC values */
147 	AFE440X_INTENSITY_CHAN(LED1, "led1", 0),
148 	AFE440X_INTENSITY_CHAN(ALED1, "led1_ambient", 0),
149 	AFE440X_INTENSITY_CHAN(LED2, "led2", 0),
150 	AFE440X_INTENSITY_CHAN(ALED2, "led2_ambient", 0),
151 	AFE440X_INTENSITY_CHAN(LED1_ALED1, "led1-led1_ambient", 0),
152 	AFE440X_INTENSITY_CHAN(LED2_ALED2, "led2-led2_ambient", 0),
153 	/* LED current */
154 	AFE440X_CURRENT_CHAN(ILED1, "led1"),
155 	AFE440X_CURRENT_CHAN(ILED2, "led2"),
156 };
157 
158 static const struct afe440x_val_table afe4403_res_table[] = {
159 	{ 500000 }, { 250000 }, { 100000 }, { 50000 },
160 	{ 25000 }, { 10000 }, { 1000000 }, { 0 },
161 };
162 AFE440X_TABLE_ATTR(tia_resistance_available, afe4403_res_table);
163 
164 static const struct afe440x_val_table afe4403_cap_table[] = {
165 	{ 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
166 	{ 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
167 	{ 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
168 	{ 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
169 	{ 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
170 	{ 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
171 	{ 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
172 	{ 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
173 };
174 AFE440X_TABLE_ATTR(tia_capacitance_available, afe4403_cap_table);
175 
176 static ssize_t afe440x_show_register(struct device *dev,
177 				     struct device_attribute *attr,
178 				     char *buf)
179 {
180 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
181 	struct afe4403_data *afe = iio_priv(indio_dev);
182 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
183 	unsigned int reg_val;
184 	int vals[2];
185 	int ret;
186 
187 	ret = regmap_read(afe->regmap, afe440x_attr->reg, &reg_val);
188 	if (ret)
189 		return ret;
190 
191 	reg_val &= afe440x_attr->mask;
192 	reg_val >>= afe440x_attr->shift;
193 
194 	if (reg_val >= afe440x_attr->table_size)
195 		return -EINVAL;
196 
197 	vals[0] = afe440x_attr->val_table[reg_val].integer;
198 	vals[1] = afe440x_attr->val_table[reg_val].fract;
199 
200 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
201 }
202 
203 static ssize_t afe440x_store_register(struct device *dev,
204 				      struct device_attribute *attr,
205 				      const char *buf, size_t count)
206 {
207 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
208 	struct afe4403_data *afe = iio_priv(indio_dev);
209 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
210 	int val, integer, fract, ret;
211 
212 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
213 	if (ret)
214 		return ret;
215 
216 	for (val = 0; val < afe440x_attr->table_size; val++)
217 		if (afe440x_attr->val_table[val].integer == integer &&
218 		    afe440x_attr->val_table[val].fract == fract)
219 			break;
220 	if (val == afe440x_attr->table_size)
221 		return -EINVAL;
222 
223 	ret = regmap_update_bits(afe->regmap, afe440x_attr->reg,
224 				 afe440x_attr->mask,
225 				 (val << afe440x_attr->shift));
226 	if (ret)
227 		return ret;
228 
229 	return count;
230 }
231 
232 static AFE440X_ATTR(tia_resistance1, AFE4403_TIAGAIN, AFE4403_TIAGAIN_RES, afe4403_res_table);
233 static AFE440X_ATTR(tia_capacitance1, AFE4403_TIAGAIN, AFE4403_TIAGAIN_CAP, afe4403_cap_table);
234 
235 static AFE440X_ATTR(tia_resistance2, AFE4403_TIA_AMB_GAIN, AFE4403_TIAGAIN_RES, afe4403_res_table);
236 static AFE440X_ATTR(tia_capacitance2, AFE4403_TIA_AMB_GAIN, AFE4403_TIAGAIN_RES, afe4403_cap_table);
237 
238 static struct attribute *afe440x_attributes[] = {
239 	&afe440x_attr_tia_resistance1.dev_attr.attr,
240 	&afe440x_attr_tia_capacitance1.dev_attr.attr,
241 	&afe440x_attr_tia_resistance2.dev_attr.attr,
242 	&afe440x_attr_tia_capacitance2.dev_attr.attr,
243 	&dev_attr_tia_resistance_available.attr,
244 	&dev_attr_tia_capacitance_available.attr,
245 	NULL
246 };
247 
248 static const struct attribute_group afe440x_attribute_group = {
249 	.attrs = afe440x_attributes
250 };
251 
252 static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
253 {
254 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
255 	u8 rx[3];
256 	int ret;
257 
258 	/* Enable reading from the device */
259 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
260 	if (ret)
261 		return ret;
262 
263 	ret = spi_write_then_read(afe->spi, &reg, 1, rx, 3);
264 	if (ret)
265 		return ret;
266 
267 	*val = (rx[0] << 16) |
268 		(rx[1] << 8) |
269 		(rx[2]);
270 
271 	/* Disable reading from the device */
272 	tx[3] = AFE440X_CONTROL0_WRITE;
273 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
274 	if (ret)
275 		return ret;
276 
277 	return 0;
278 }
279 
280 static int afe4403_read_raw(struct iio_dev *indio_dev,
281 			    struct iio_chan_spec const *chan,
282 			    int *val, int *val2, long mask)
283 {
284 	struct afe4403_data *afe = iio_priv(indio_dev);
285 	const struct afe440x_reg_info reg_info = afe4403_reg_info[chan->address];
286 	int ret;
287 
288 	switch (chan->type) {
289 	case IIO_INTENSITY:
290 		switch (mask) {
291 		case IIO_CHAN_INFO_RAW:
292 			ret = afe4403_read(afe, reg_info.reg, val);
293 			if (ret)
294 				return ret;
295 			return IIO_VAL_INT;
296 		}
297 		break;
298 	case IIO_CURRENT:
299 		switch (mask) {
300 		case IIO_CHAN_INFO_RAW:
301 			ret = regmap_read(afe->regmap, reg_info.reg, val);
302 			if (ret)
303 				return ret;
304 			*val &= reg_info.mask;
305 			*val >>= reg_info.shift;
306 			return IIO_VAL_INT;
307 		case IIO_CHAN_INFO_SCALE:
308 			*val = 0;
309 			*val2 = 800000;
310 			return IIO_VAL_INT_PLUS_MICRO;
311 		}
312 		break;
313 	default:
314 		break;
315 	}
316 
317 	return -EINVAL;
318 }
319 
320 static int afe4403_write_raw(struct iio_dev *indio_dev,
321 			     struct iio_chan_spec const *chan,
322 			     int val, int val2, long mask)
323 {
324 	struct afe4403_data *afe = iio_priv(indio_dev);
325 	const struct afe440x_reg_info reg_info = afe4403_reg_info[chan->address];
326 
327 	switch (chan->type) {
328 	case IIO_CURRENT:
329 		switch (mask) {
330 		case IIO_CHAN_INFO_RAW:
331 			return regmap_update_bits(afe->regmap,
332 				reg_info.reg,
333 				reg_info.mask,
334 				(val << reg_info.shift));
335 		}
336 		break;
337 	default:
338 		break;
339 	}
340 
341 	return -EINVAL;
342 }
343 
344 static const struct iio_info afe4403_iio_info = {
345 	.attrs = &afe440x_attribute_group,
346 	.read_raw = afe4403_read_raw,
347 	.write_raw = afe4403_write_raw,
348 	.driver_module = THIS_MODULE,
349 };
350 
351 static irqreturn_t afe4403_trigger_handler(int irq, void *private)
352 {
353 	struct iio_poll_func *pf = private;
354 	struct iio_dev *indio_dev = pf->indio_dev;
355 	struct afe4403_data *afe = iio_priv(indio_dev);
356 	int ret, bit, i = 0;
357 	s32 buffer[8];
358 	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
359 	u8 rx[3];
360 
361 	/* Enable reading from the device */
362 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
363 	if (ret)
364 		goto err;
365 
366 	for_each_set_bit(bit, indio_dev->active_scan_mask,
367 			 indio_dev->masklength) {
368 		ret = spi_write_then_read(afe->spi,
369 					  &afe4403_reg_info[bit].reg, 1,
370 					  rx, 3);
371 		if (ret)
372 			goto err;
373 
374 		buffer[i++] = (rx[0] << 16) |
375 				(rx[1] << 8) |
376 				(rx[2]);
377 	}
378 
379 	/* Disable reading from the device */
380 	tx[3] = AFE440X_CONTROL0_WRITE;
381 	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
382 	if (ret)
383 		goto err;
384 
385 	iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
386 err:
387 	iio_trigger_notify_done(indio_dev->trig);
388 
389 	return IRQ_HANDLED;
390 }
391 
392 static const struct iio_trigger_ops afe4403_trigger_ops = {
393 	.owner = THIS_MODULE,
394 };
395 
396 #define AFE4403_TIMING_PAIRS			\
397 	{ AFE440X_LED2STC,	0x000050 },	\
398 	{ AFE440X_LED2ENDC,	0x0003e7 },	\
399 	{ AFE440X_LED1LEDSTC,	0x0007d0 },	\
400 	{ AFE440X_LED1LEDENDC,	0x000bb7 },	\
401 	{ AFE440X_ALED2STC,	0x000438 },	\
402 	{ AFE440X_ALED2ENDC,	0x0007cf },	\
403 	{ AFE440X_LED1STC,	0x000820 },	\
404 	{ AFE440X_LED1ENDC,	0x000bb7 },	\
405 	{ AFE440X_LED2LEDSTC,	0x000000 },	\
406 	{ AFE440X_LED2LEDENDC,	0x0003e7 },	\
407 	{ AFE440X_ALED1STC,	0x000c08 },	\
408 	{ AFE440X_ALED1ENDC,	0x000f9f },	\
409 	{ AFE440X_LED2CONVST,	0x0003ef },	\
410 	{ AFE440X_LED2CONVEND,	0x0007cf },	\
411 	{ AFE440X_ALED2CONVST,	0x0007d7 },	\
412 	{ AFE440X_ALED2CONVEND,	0x000bb7 },	\
413 	{ AFE440X_LED1CONVST,	0x000bbf },	\
414 	{ AFE440X_LED1CONVEND,	0x009c3f },	\
415 	{ AFE440X_ALED1CONVST,	0x000fa7 },	\
416 	{ AFE440X_ALED1CONVEND,	0x001387 },	\
417 	{ AFE440X_ADCRSTSTCT0,	0x0003e8 },	\
418 	{ AFE440X_ADCRSTENDCT0,	0x0003eb },	\
419 	{ AFE440X_ADCRSTSTCT1,	0x0007d0 },	\
420 	{ AFE440X_ADCRSTENDCT1,	0x0007d3 },	\
421 	{ AFE440X_ADCRSTSTCT2,	0x000bb8 },	\
422 	{ AFE440X_ADCRSTENDCT2,	0x000bbb },	\
423 	{ AFE440X_ADCRSTSTCT3,	0x000fa0 },	\
424 	{ AFE440X_ADCRSTENDCT3,	0x000fa3 },	\
425 	{ AFE440X_PRPCOUNT,	0x009c3f },	\
426 	{ AFE440X_PDNCYCLESTC,	0x001518 },	\
427 	{ AFE440X_PDNCYCLEENDC,	0x00991f }
428 
429 static const struct reg_sequence afe4403_reg_sequences[] = {
430 	AFE4403_TIMING_PAIRS,
431 	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
432 	{ AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
433 };
434 
435 static const struct regmap_range afe4403_yes_ranges[] = {
436 	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
437 };
438 
439 static const struct regmap_access_table afe4403_volatile_table = {
440 	.yes_ranges = afe4403_yes_ranges,
441 	.n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
442 };
443 
444 static const struct regmap_config afe4403_regmap_config = {
445 	.reg_bits = 8,
446 	.val_bits = 24,
447 
448 	.max_register = AFE440X_PDNCYCLEENDC,
449 	.cache_type = REGCACHE_RBTREE,
450 	.volatile_table = &afe4403_volatile_table,
451 };
452 
453 static const struct of_device_id afe4403_of_match[] = {
454 	{ .compatible = "ti,afe4403", },
455 	{ /* sentinel */ }
456 };
457 MODULE_DEVICE_TABLE(of, afe4403_of_match);
458 
459 static int __maybe_unused afe4403_suspend(struct device *dev)
460 {
461 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
462 	struct afe4403_data *afe = iio_priv(indio_dev);
463 	int ret;
464 
465 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
466 				 AFE440X_CONTROL2_PDN_AFE,
467 				 AFE440X_CONTROL2_PDN_AFE);
468 	if (ret)
469 		return ret;
470 
471 	ret = regulator_disable(afe->regulator);
472 	if (ret) {
473 		dev_err(dev, "Unable to disable regulator\n");
474 		return ret;
475 	}
476 
477 	return 0;
478 }
479 
480 static int __maybe_unused afe4403_resume(struct device *dev)
481 {
482 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
483 	struct afe4403_data *afe = iio_priv(indio_dev);
484 	int ret;
485 
486 	ret = regulator_enable(afe->regulator);
487 	if (ret) {
488 		dev_err(dev, "Unable to enable regulator\n");
489 		return ret;
490 	}
491 
492 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
493 				 AFE440X_CONTROL2_PDN_AFE, 0);
494 	if (ret)
495 		return ret;
496 
497 	return 0;
498 }
499 
500 static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
501 
502 static int afe4403_probe(struct spi_device *spi)
503 {
504 	struct iio_dev *indio_dev;
505 	struct afe4403_data *afe;
506 	int ret;
507 
508 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
509 	if (!indio_dev)
510 		return -ENOMEM;
511 
512 	afe = iio_priv(indio_dev);
513 	spi_set_drvdata(spi, indio_dev);
514 
515 	afe->dev = &spi->dev;
516 	afe->spi = spi;
517 	afe->irq = spi->irq;
518 
519 	afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
520 	if (IS_ERR(afe->regmap)) {
521 		dev_err(afe->dev, "Unable to allocate register map\n");
522 		return PTR_ERR(afe->regmap);
523 	}
524 
525 	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
526 	if (IS_ERR(afe->regulator)) {
527 		dev_err(afe->dev, "Unable to get regulator\n");
528 		return PTR_ERR(afe->regulator);
529 	}
530 	ret = regulator_enable(afe->regulator);
531 	if (ret) {
532 		dev_err(afe->dev, "Unable to enable regulator\n");
533 		return ret;
534 	}
535 
536 	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
537 			   AFE440X_CONTROL0_SW_RESET);
538 	if (ret) {
539 		dev_err(afe->dev, "Unable to reset device\n");
540 		goto err_disable_reg;
541 	}
542 
543 	ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
544 				     ARRAY_SIZE(afe4403_reg_sequences));
545 	if (ret) {
546 		dev_err(afe->dev, "Unable to set register defaults\n");
547 		goto err_disable_reg;
548 	}
549 
550 	indio_dev->modes = INDIO_DIRECT_MODE;
551 	indio_dev->dev.parent = afe->dev;
552 	indio_dev->channels = afe4403_channels;
553 	indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
554 	indio_dev->name = AFE4403_DRIVER_NAME;
555 	indio_dev->info = &afe4403_iio_info;
556 
557 	if (afe->irq > 0) {
558 		afe->trig = devm_iio_trigger_alloc(afe->dev,
559 						   "%s-dev%d",
560 						   indio_dev->name,
561 						   indio_dev->id);
562 		if (!afe->trig) {
563 			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
564 			ret = -ENOMEM;
565 			goto err_disable_reg;
566 		}
567 
568 		iio_trigger_set_drvdata(afe->trig, indio_dev);
569 
570 		afe->trig->ops = &afe4403_trigger_ops;
571 		afe->trig->dev.parent = afe->dev;
572 
573 		ret = iio_trigger_register(afe->trig);
574 		if (ret) {
575 			dev_err(afe->dev, "Unable to register IIO trigger\n");
576 			goto err_disable_reg;
577 		}
578 
579 		ret = devm_request_threaded_irq(afe->dev, afe->irq,
580 						iio_trigger_generic_data_rdy_poll,
581 						NULL, IRQF_ONESHOT,
582 						AFE4403_DRIVER_NAME,
583 						afe->trig);
584 		if (ret) {
585 			dev_err(afe->dev, "Unable to request IRQ\n");
586 			goto err_trig;
587 		}
588 	}
589 
590 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
591 					 afe4403_trigger_handler, NULL);
592 	if (ret) {
593 		dev_err(afe->dev, "Unable to setup buffer\n");
594 		goto err_trig;
595 	}
596 
597 	ret = iio_device_register(indio_dev);
598 	if (ret) {
599 		dev_err(afe->dev, "Unable to register IIO device\n");
600 		goto err_buff;
601 	}
602 
603 	return 0;
604 
605 err_buff:
606 	iio_triggered_buffer_cleanup(indio_dev);
607 err_trig:
608 	if (afe->irq > 0)
609 		iio_trigger_unregister(afe->trig);
610 err_disable_reg:
611 	regulator_disable(afe->regulator);
612 
613 	return ret;
614 }
615 
616 static int afe4403_remove(struct spi_device *spi)
617 {
618 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
619 	struct afe4403_data *afe = iio_priv(indio_dev);
620 	int ret;
621 
622 	iio_device_unregister(indio_dev);
623 
624 	iio_triggered_buffer_cleanup(indio_dev);
625 
626 	if (afe->irq > 0)
627 		iio_trigger_unregister(afe->trig);
628 
629 	ret = regulator_disable(afe->regulator);
630 	if (ret) {
631 		dev_err(afe->dev, "Unable to disable regulator\n");
632 		return ret;
633 	}
634 
635 	return 0;
636 }
637 
638 static const struct spi_device_id afe4403_ids[] = {
639 	{ "afe4403", 0 },
640 	{ /* sentinel */ }
641 };
642 MODULE_DEVICE_TABLE(spi, afe4403_ids);
643 
644 static struct spi_driver afe4403_spi_driver = {
645 	.driver = {
646 		.name = AFE4403_DRIVER_NAME,
647 		.of_match_table = afe4403_of_match,
648 		.pm = &afe4403_pm_ops,
649 	},
650 	.probe = afe4403_probe,
651 	.remove = afe4403_remove,
652 	.id_table = afe4403_ids,
653 };
654 module_spi_driver(afe4403_spi_driver);
655 
656 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
657 MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
658 MODULE_LICENSE("GPL v2");
659