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
36enum 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
48static 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 */
70struct 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
82enum afe4403_chan_id {
83	LED2 = 1,
84	ALED2,
85	LED1,
86	ALED1,
87	LED2_ALED2,
88	LED1_ALED1,
89};
90
91static 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
100static const unsigned int afe4403_channel_leds[] = {
101	[LED2] = F_ILED2,
102	[LED1] = F_ILED1,
103};
104
105static 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
118static const struct afe440x_val_table afe4403_res_table[] = {
119	{ 500000 }, { 250000 }, { 100000 }, { 50000 },
120	{ 25000 }, { 10000 }, { 1000000 }, { 0 },
121};
122AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4403_res_table);
123
124static 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};
134AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4403_cap_table);
135
136static 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
160static 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
187static AFE440X_ATTR(in_intensity1_resistance, F_RF_LED, afe4403_res_table);
188static AFE440X_ATTR(in_intensity1_capacitance, F_CF_LED, afe4403_cap_table);
189
190static AFE440X_ATTR(in_intensity2_resistance, F_RF_LED, afe4403_res_table);
191static AFE440X_ATTR(in_intensity2_capacitance, F_CF_LED, afe4403_cap_table);
192
193static AFE440X_ATTR(in_intensity3_resistance, F_RF_LED1, afe4403_res_table);
194static AFE440X_ATTR(in_intensity3_capacitance, F_CF_LED1, afe4403_cap_table);
195
196static AFE440X_ATTR(in_intensity4_resistance, F_RF_LED1, afe4403_res_table);
197static AFE440X_ATTR(in_intensity4_capacitance, F_CF_LED1, afe4403_cap_table);
198
199static 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
213static const struct attribute_group afe440x_attribute_group = {
214	.attrs = afe440x_attributes
215};
216
217static 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
243static 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, field;
249	int ret;
250
251	switch (chan->type) {
252	case IIO_INTENSITY:
253		switch (mask) {
254		case IIO_CHAN_INFO_RAW:
255			reg = afe4403_channel_values[chan->address];
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			field = afe4403_channel_leds[chan->address];
266			ret = regmap_field_read(afe->fields[field], val);
267			if (ret)
268				return ret;
269			return IIO_VAL_INT;
270		case IIO_CHAN_INFO_SCALE:
271			*val = 0;
272			*val2 = 800000;
273			return IIO_VAL_INT_PLUS_MICRO;
274		}
275		break;
276	default:
277		break;
278	}
279
280	return -EINVAL;
281}
282
283static int afe4403_write_raw(struct iio_dev *indio_dev,
284			     struct iio_chan_spec const *chan,
285			     int val, int val2, long mask)
286{
287	struct afe4403_data *afe = iio_priv(indio_dev);
288	unsigned int field = afe4403_channel_leds[chan->address];
289
290	switch (chan->type) {
291	case IIO_CURRENT:
292		switch (mask) {
293		case IIO_CHAN_INFO_RAW:
294			return regmap_field_write(afe->fields[field], val);
295		}
296		break;
297	default:
298		break;
299	}
300
301	return -EINVAL;
302}
303
304static const struct iio_info afe4403_iio_info = {
305	.attrs = &afe440x_attribute_group,
306	.read_raw = afe4403_read_raw,
307	.write_raw = afe4403_write_raw,
308};
309
310static irqreturn_t afe4403_trigger_handler(int irq, void *private)
311{
312	struct iio_poll_func *pf = private;
313	struct iio_dev *indio_dev = pf->indio_dev;
314	struct afe4403_data *afe = iio_priv(indio_dev);
315	int ret, bit, i = 0;
316	u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
317	u8 rx[3];
318
319	/* Enable reading from the device */
320	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
321	if (ret)
322		goto err;
323
324	for_each_set_bit(bit, indio_dev->active_scan_mask,
325			 indio_dev->masklength) {
326		ret = spi_write_then_read(afe->spi,
327					  &afe4403_channel_values[bit], 1,
328					  rx, sizeof(rx));
329		if (ret)
330			goto err;
331
332		afe->buffer[i++] = get_unaligned_be24(&rx[0]);
333	}
334
335	/* Disable reading from the device */
336	tx[3] = AFE440X_CONTROL0_WRITE;
337	ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
338	if (ret)
339		goto err;
340
341	iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
342					   pf->timestamp);
343err:
344	iio_trigger_notify_done(indio_dev->trig);
345
346	return IRQ_HANDLED;
347}
348
349static void afe4403_regulator_disable(void *data)
350{
351	struct regulator *regulator = data;
352
353	regulator_disable(regulator);
354}
355
356#define AFE4403_TIMING_PAIRS			\
357	{ AFE440X_LED2STC,	0x000050 },	\
358	{ AFE440X_LED2ENDC,	0x0003e7 },	\
359	{ AFE440X_LED1LEDSTC,	0x0007d0 },	\
360	{ AFE440X_LED1LEDENDC,	0x000bb7 },	\
361	{ AFE440X_ALED2STC,	0x000438 },	\
362	{ AFE440X_ALED2ENDC,	0x0007cf },	\
363	{ AFE440X_LED1STC,	0x000820 },	\
364	{ AFE440X_LED1ENDC,	0x000bb7 },	\
365	{ AFE440X_LED2LEDSTC,	0x000000 },	\
366	{ AFE440X_LED2LEDENDC,	0x0003e7 },	\
367	{ AFE440X_ALED1STC,	0x000c08 },	\
368	{ AFE440X_ALED1ENDC,	0x000f9f },	\
369	{ AFE440X_LED2CONVST,	0x0003ef },	\
370	{ AFE440X_LED2CONVEND,	0x0007cf },	\
371	{ AFE440X_ALED2CONVST,	0x0007d7 },	\
372	{ AFE440X_ALED2CONVEND,	0x000bb7 },	\
373	{ AFE440X_LED1CONVST,	0x000bbf },	\
374	{ AFE440X_LED1CONVEND,	0x009c3f },	\
375	{ AFE440X_ALED1CONVST,	0x000fa7 },	\
376	{ AFE440X_ALED1CONVEND,	0x001387 },	\
377	{ AFE440X_ADCRSTSTCT0,	0x0003e8 },	\
378	{ AFE440X_ADCRSTENDCT0,	0x0003eb },	\
379	{ AFE440X_ADCRSTSTCT1,	0x0007d0 },	\
380	{ AFE440X_ADCRSTENDCT1,	0x0007d3 },	\
381	{ AFE440X_ADCRSTSTCT2,	0x000bb8 },	\
382	{ AFE440X_ADCRSTENDCT2,	0x000bbb },	\
383	{ AFE440X_ADCRSTSTCT3,	0x000fa0 },	\
384	{ AFE440X_ADCRSTENDCT3,	0x000fa3 },	\
385	{ AFE440X_PRPCOUNT,	0x009c3f },	\
386	{ AFE440X_PDNCYCLESTC,	0x001518 },	\
387	{ AFE440X_PDNCYCLEENDC,	0x00991f }
388
389static const struct reg_sequence afe4403_reg_sequences[] = {
390	AFE4403_TIMING_PAIRS,
391	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
392	{ AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
393};
394
395static const struct regmap_range afe4403_yes_ranges[] = {
396	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
397};
398
399static const struct regmap_access_table afe4403_volatile_table = {
400	.yes_ranges = afe4403_yes_ranges,
401	.n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
402};
403
404static const struct regmap_config afe4403_regmap_config = {
405	.reg_bits = 8,
406	.val_bits = 24,
407
408	.max_register = AFE440X_PDNCYCLEENDC,
409	.cache_type = REGCACHE_RBTREE,
410	.volatile_table = &afe4403_volatile_table,
411};
412
413static const struct of_device_id afe4403_of_match[] = {
414	{ .compatible = "ti,afe4403", },
415	{ /* sentinel */ }
416};
417MODULE_DEVICE_TABLE(of, afe4403_of_match);
418
419static int afe4403_suspend(struct device *dev)
420{
421	struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
422	struct afe4403_data *afe = iio_priv(indio_dev);
423	int ret;
424
425	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
426				 AFE440X_CONTROL2_PDN_AFE,
427				 AFE440X_CONTROL2_PDN_AFE);
428	if (ret)
429		return ret;
430
431	ret = regulator_disable(afe->regulator);
432	if (ret) {
433		dev_err(dev, "Unable to disable regulator\n");
434		return ret;
435	}
436
437	return 0;
438}
439
440static int afe4403_resume(struct device *dev)
441{
442	struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
443	struct afe4403_data *afe = iio_priv(indio_dev);
444	int ret;
445
446	ret = regulator_enable(afe->regulator);
447	if (ret) {
448		dev_err(dev, "Unable to enable regulator\n");
449		return ret;
450	}
451
452	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
453				 AFE440X_CONTROL2_PDN_AFE, 0);
454	if (ret)
455		return ret;
456
457	return 0;
458}
459
460static DEFINE_SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend,
461				afe4403_resume);
462
463static int afe4403_probe(struct spi_device *spi)
464{
465	struct iio_dev *indio_dev;
466	struct afe4403_data *afe;
467	int i, ret;
468
469	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
470	if (!indio_dev)
471		return -ENOMEM;
472
473	afe = iio_priv(indio_dev);
474	spi_set_drvdata(spi, indio_dev);
475
476	afe->dev = &spi->dev;
477	afe->spi = spi;
478	afe->irq = spi->irq;
479
480	afe->regmap = devm_regmap_init_spi(spi, &afe4403_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							 afe4403_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	ret = devm_add_action_or_reset(afe->dev, afe4403_regulator_disable, afe->regulator);
506	if (ret) {
507		dev_err(afe->dev, "Unable to add regulator disable action\n");
508		return ret;
509	}
510
511	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
512			   AFE440X_CONTROL0_SW_RESET);
513	if (ret) {
514		dev_err(afe->dev, "Unable to reset device\n");
515		return ret;
516	}
517
518	ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
519				     ARRAY_SIZE(afe4403_reg_sequences));
520	if (ret) {
521		dev_err(afe->dev, "Unable to set register defaults\n");
522		return ret;
523	}
524
525	indio_dev->modes = INDIO_DIRECT_MODE;
526	indio_dev->channels = afe4403_channels;
527	indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
528	indio_dev->name = AFE4403_DRIVER_NAME;
529	indio_dev->info = &afe4403_iio_info;
530
531	if (afe->irq > 0) {
532		afe->trig = devm_iio_trigger_alloc(afe->dev,
533						   "%s-dev%d",
534						   indio_dev->name,
535						   iio_device_id(indio_dev));
536		if (!afe->trig) {
537			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
538			return -ENOMEM;
539		}
540
541		iio_trigger_set_drvdata(afe->trig, indio_dev);
542
543		ret = devm_iio_trigger_register(afe->dev, afe->trig);
544		if (ret) {
545			dev_err(afe->dev, "Unable to register IIO trigger\n");
546			return ret;
547		}
548
549		ret = devm_request_threaded_irq(afe->dev, afe->irq,
550						iio_trigger_generic_data_rdy_poll,
551						NULL, IRQF_ONESHOT,
552						AFE4403_DRIVER_NAME,
553						afe->trig);
554		if (ret) {
555			dev_err(afe->dev, "Unable to request IRQ\n");
556			return ret;
557		}
558	}
559
560	ret = devm_iio_triggered_buffer_setup(afe->dev, indio_dev,
561					      &iio_pollfunc_store_time,
562					      afe4403_trigger_handler, NULL);
563	if (ret) {
564		dev_err(afe->dev, "Unable to setup buffer\n");
565		return ret;
566	}
567
568	ret = devm_iio_device_register(afe->dev, indio_dev);
569	if (ret) {
570		dev_err(afe->dev, "Unable to register IIO device\n");
571		return ret;
572	}
573
574	return 0;
575}
576
577static const struct spi_device_id afe4403_ids[] = {
578	{ "afe4403", 0 },
579	{ /* sentinel */ }
580};
581MODULE_DEVICE_TABLE(spi, afe4403_ids);
582
583static struct spi_driver afe4403_spi_driver = {
584	.driver = {
585		.name = AFE4403_DRIVER_NAME,
586		.of_match_table = afe4403_of_match,
587		.pm = pm_sleep_ptr(&afe4403_pm_ops),
588	},
589	.probe = afe4403_probe,
590	.id_table = afe4403_ids,
591};
592module_spi_driver(afe4403_spi_driver);
593
594MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
595MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
596MODULE_LICENSE("GPL v2");
597