GNU Linux-libre 4.9.309-gnu1
[releases.git] / drivers / iio / health / afe4404.c
1 /*
2  * AFE4404 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/i2c.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/regmap.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 AFE4404_DRIVER_NAME             "afe4404"
37
38 /* AFE4404 registers */
39 #define AFE4404_TIA_GAIN_SEP            0x20
40 #define AFE4404_TIA_GAIN                0x21
41 #define AFE4404_PROG_TG_STC             0x34
42 #define AFE4404_PROG_TG_ENDC            0x35
43 #define AFE4404_LED3LEDSTC              0x36
44 #define AFE4404_LED3LEDENDC             0x37
45 #define AFE4404_CLKDIV_PRF              0x39
46 #define AFE4404_OFFDAC                  0x3a
47 #define AFE4404_DEC                     0x3d
48 #define AFE4404_AVG_LED2_ALED2VAL       0x3f
49 #define AFE4404_AVG_LED1_ALED1VAL       0x40
50
51 /* AFE4404 CONTROL2 register fields */
52 #define AFE440X_CONTROL2_OSC_ENABLE     BIT(9)
53
54 enum afe4404_fields {
55         /* Gains */
56         F_TIA_GAIN_SEP, F_TIA_CF_SEP,
57         F_TIA_GAIN, TIA_CF,
58
59         /* LED Current */
60         F_ILED1, F_ILED2, F_ILED3,
61
62         /* Offset DAC */
63         F_OFFDAC_AMB2, F_OFFDAC_LED1, F_OFFDAC_AMB1, F_OFFDAC_LED2,
64
65         /* sentinel */
66         F_MAX_FIELDS
67 };
68
69 static const struct reg_field afe4404_reg_fields[] = {
70         /* Gains */
71         [F_TIA_GAIN_SEP]        = REG_FIELD(AFE4404_TIA_GAIN_SEP, 0, 2),
72         [F_TIA_CF_SEP]          = REG_FIELD(AFE4404_TIA_GAIN_SEP, 3, 5),
73         [F_TIA_GAIN]            = REG_FIELD(AFE4404_TIA_GAIN, 0, 2),
74         [TIA_CF]                = REG_FIELD(AFE4404_TIA_GAIN, 3, 5),
75         /* LED Current */
76         [F_ILED1]               = REG_FIELD(AFE440X_LEDCNTRL, 0, 5),
77         [F_ILED2]               = REG_FIELD(AFE440X_LEDCNTRL, 6, 11),
78         [F_ILED3]               = REG_FIELD(AFE440X_LEDCNTRL, 12, 17),
79         /* Offset DAC */
80         [F_OFFDAC_AMB2]         = REG_FIELD(AFE4404_OFFDAC, 0, 4),
81         [F_OFFDAC_LED1]         = REG_FIELD(AFE4404_OFFDAC, 5, 9),
82         [F_OFFDAC_AMB1]         = REG_FIELD(AFE4404_OFFDAC, 10, 14),
83         [F_OFFDAC_LED2]         = REG_FIELD(AFE4404_OFFDAC, 15, 19),
84 };
85
86 /**
87  * struct afe4404_data - AFE4404 device instance data
88  * @dev: Device structure
89  * @regmap: Register map of the device
90  * @fields: Register fields of the device
91  * @regulator: Pointer to the regulator for the IC
92  * @trig: IIO trigger for this device
93  * @irq: ADC_RDY line interrupt number
94  * @buffer: Used to construct a scan to push to the iio buffer.
95  */
96 struct afe4404_data {
97         struct device *dev;
98         struct regmap *regmap;
99         struct regmap_field *fields[F_MAX_FIELDS];
100         struct regulator *regulator;
101         struct iio_trigger *trig;
102         int irq;
103         s32 buffer[10] __aligned(8);
104 };
105
106 enum afe4404_chan_id {
107         LED2 = 1,
108         ALED2,
109         LED1,
110         ALED1,
111         LED2_ALED2,
112         LED1_ALED1,
113 };
114
115 static const unsigned int afe4404_channel_values[] = {
116         [LED2] = AFE440X_LED2VAL,
117         [ALED2] = AFE440X_ALED2VAL,
118         [LED1] = AFE440X_LED1VAL,
119         [ALED1] = AFE440X_ALED1VAL,
120         [LED2_ALED2] = AFE440X_LED2_ALED2VAL,
121         [LED1_ALED1] = AFE440X_LED1_ALED1VAL,
122 };
123
124 static const unsigned int afe4404_channel_leds[] = {
125         [LED2] = F_ILED2,
126         [ALED2] = F_ILED3,
127         [LED1] = F_ILED1,
128 };
129
130 static const unsigned int afe4404_channel_offdacs[] = {
131         [LED2] = F_OFFDAC_LED2,
132         [ALED2] = F_OFFDAC_AMB2,
133         [LED1] = F_OFFDAC_LED1,
134         [ALED1] = F_OFFDAC_AMB1,
135 };
136
137 static const struct iio_chan_spec afe4404_channels[] = {
138         /* ADC values */
139         AFE440X_INTENSITY_CHAN(LED2, BIT(IIO_CHAN_INFO_OFFSET)),
140         AFE440X_INTENSITY_CHAN(ALED2, BIT(IIO_CHAN_INFO_OFFSET)),
141         AFE440X_INTENSITY_CHAN(LED1, BIT(IIO_CHAN_INFO_OFFSET)),
142         AFE440X_INTENSITY_CHAN(ALED1, BIT(IIO_CHAN_INFO_OFFSET)),
143         AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
144         AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
145         /* LED current */
146         AFE440X_CURRENT_CHAN(LED2),
147         AFE440X_CURRENT_CHAN(ALED2),
148         AFE440X_CURRENT_CHAN(LED1),
149 };
150
151 static const struct afe440x_val_table afe4404_res_table[] = {
152         { .integer = 500000, .fract = 0 },
153         { .integer = 250000, .fract = 0 },
154         { .integer = 100000, .fract = 0 },
155         { .integer = 50000, .fract = 0 },
156         { .integer = 25000, .fract = 0 },
157         { .integer = 10000, .fract = 0 },
158         { .integer = 1000000, .fract = 0 },
159         { .integer = 2000000, .fract = 0 },
160 };
161 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4404_res_table);
162
163 static const struct afe440x_val_table afe4404_cap_table[] = {
164         { .integer = 0, .fract = 5000 },
165         { .integer = 0, .fract = 2500 },
166         { .integer = 0, .fract = 10000 },
167         { .integer = 0, .fract = 7500 },
168         { .integer = 0, .fract = 20000 },
169         { .integer = 0, .fract = 17500 },
170         { .integer = 0, .fract = 25000 },
171         { .integer = 0, .fract = 22500 },
172 };
173 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4404_cap_table);
174
175 static ssize_t afe440x_show_register(struct device *dev,
176                                      struct device_attribute *attr,
177                                      char *buf)
178 {
179         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
180         struct afe4404_data *afe = iio_priv(indio_dev);
181         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
182         unsigned int reg_val;
183         int vals[2];
184         int ret;
185
186         ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
187         if (ret)
188                 return ret;
189
190         if (reg_val >= afe440x_attr->table_size)
191                 return -EINVAL;
192
193         vals[0] = afe440x_attr->val_table[reg_val].integer;
194         vals[1] = afe440x_attr->val_table[reg_val].fract;
195
196         return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
197 }
198
199 static ssize_t afe440x_store_register(struct device *dev,
200                                       struct device_attribute *attr,
201                                       const char *buf, size_t count)
202 {
203         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
204         struct afe4404_data *afe = iio_priv(indio_dev);
205         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
206         int val, integer, fract, ret;
207
208         ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
209         if (ret)
210                 return ret;
211
212         for (val = 0; val < afe440x_attr->table_size; val++)
213                 if (afe440x_attr->val_table[val].integer == integer &&
214                     afe440x_attr->val_table[val].fract == fract)
215                         break;
216         if (val == afe440x_attr->table_size)
217                 return -EINVAL;
218
219         ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
220         if (ret)
221                 return ret;
222
223         return count;
224 }
225
226 static AFE440X_ATTR(in_intensity1_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
227 static AFE440X_ATTR(in_intensity1_capacitance, F_TIA_CF_SEP, afe4404_cap_table);
228
229 static AFE440X_ATTR(in_intensity2_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
230 static AFE440X_ATTR(in_intensity2_capacitance, F_TIA_CF_SEP, afe4404_cap_table);
231
232 static AFE440X_ATTR(in_intensity3_resistance, F_TIA_GAIN, afe4404_res_table);
233 static AFE440X_ATTR(in_intensity3_capacitance, TIA_CF, afe4404_cap_table);
234
235 static AFE440X_ATTR(in_intensity4_resistance, F_TIA_GAIN, afe4404_res_table);
236 static AFE440X_ATTR(in_intensity4_capacitance, TIA_CF, afe4404_cap_table);
237
238 static struct attribute *afe440x_attributes[] = {
239         &dev_attr_in_intensity_resistance_available.attr,
240         &dev_attr_in_intensity_capacitance_available.attr,
241         &afe440x_attr_in_intensity1_resistance.dev_attr.attr,
242         &afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
243         &afe440x_attr_in_intensity2_resistance.dev_attr.attr,
244         &afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
245         &afe440x_attr_in_intensity3_resistance.dev_attr.attr,
246         &afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
247         &afe440x_attr_in_intensity4_resistance.dev_attr.attr,
248         &afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
249         NULL
250 };
251
252 static const struct attribute_group afe440x_attribute_group = {
253         .attrs = afe440x_attributes
254 };
255
256 static int afe4404_read_raw(struct iio_dev *indio_dev,
257                             struct iio_chan_spec const *chan,
258                             int *val, int *val2, long mask)
259 {
260         struct afe4404_data *afe = iio_priv(indio_dev);
261         unsigned int value_reg = afe4404_channel_values[chan->address];
262         unsigned int led_field = afe4404_channel_leds[chan->address];
263         unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
264         int ret;
265
266         switch (chan->type) {
267         case IIO_INTENSITY:
268                 switch (mask) {
269                 case IIO_CHAN_INFO_RAW:
270                         ret = regmap_read(afe->regmap, value_reg, val);
271                         if (ret)
272                                 return ret;
273                         return IIO_VAL_INT;
274                 case IIO_CHAN_INFO_OFFSET:
275                         ret = regmap_field_read(afe->fields[offdac_field], val);
276                         if (ret)
277                                 return ret;
278                         return IIO_VAL_INT;
279                 }
280                 break;
281         case IIO_CURRENT:
282                 switch (mask) {
283                 case IIO_CHAN_INFO_RAW:
284                         ret = regmap_field_read(afe->fields[led_field], val);
285                         if (ret)
286                                 return ret;
287                         return IIO_VAL_INT;
288                 case IIO_CHAN_INFO_SCALE:
289                         *val = 0;
290                         *val2 = 800000;
291                         return IIO_VAL_INT_PLUS_MICRO;
292                 }
293                 break;
294         default:
295                 break;
296         }
297
298         return -EINVAL;
299 }
300
301 static int afe4404_write_raw(struct iio_dev *indio_dev,
302                              struct iio_chan_spec const *chan,
303                              int val, int val2, long mask)
304 {
305         struct afe4404_data *afe = iio_priv(indio_dev);
306         unsigned int led_field = afe4404_channel_leds[chan->address];
307         unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
308
309         switch (chan->type) {
310         case IIO_INTENSITY:
311                 switch (mask) {
312                 case IIO_CHAN_INFO_OFFSET:
313                         return regmap_field_write(afe->fields[offdac_field], val);
314                 }
315                 break;
316         case IIO_CURRENT:
317                 switch (mask) {
318                 case IIO_CHAN_INFO_RAW:
319                         return regmap_field_write(afe->fields[led_field], val);
320                 }
321                 break;
322         default:
323                 break;
324         }
325
326         return -EINVAL;
327 }
328
329 static const struct iio_info afe4404_iio_info = {
330         .attrs = &afe440x_attribute_group,
331         .read_raw = afe4404_read_raw,
332         .write_raw = afe4404_write_raw,
333         .driver_module = THIS_MODULE,
334 };
335
336 static irqreturn_t afe4404_trigger_handler(int irq, void *private)
337 {
338         struct iio_poll_func *pf = private;
339         struct iio_dev *indio_dev = pf->indio_dev;
340         struct afe4404_data *afe = iio_priv(indio_dev);
341         int ret, bit, i = 0;
342
343         for_each_set_bit(bit, indio_dev->active_scan_mask,
344                          indio_dev->masklength) {
345                 ret = regmap_read(afe->regmap, afe4404_channel_values[bit],
346                                   &afe->buffer[i++]);
347                 if (ret)
348                         goto err;
349         }
350
351         iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
352                                            pf->timestamp);
353 err:
354         iio_trigger_notify_done(indio_dev->trig);
355
356         return IRQ_HANDLED;
357 }
358
359 static const struct iio_trigger_ops afe4404_trigger_ops = {
360         .owner = THIS_MODULE,
361 };
362
363 /* Default timings from data-sheet */
364 #define AFE4404_TIMING_PAIRS                    \
365         { AFE440X_PRPCOUNT,     39999   },      \
366         { AFE440X_LED2LEDSTC,   0       },      \
367         { AFE440X_LED2LEDENDC,  398     },      \
368         { AFE440X_LED2STC,      80      },      \
369         { AFE440X_LED2ENDC,     398     },      \
370         { AFE440X_ADCRSTSTCT0,  5600    },      \
371         { AFE440X_ADCRSTENDCT0, 5606    },      \
372         { AFE440X_LED2CONVST,   5607    },      \
373         { AFE440X_LED2CONVEND,  6066    },      \
374         { AFE4404_LED3LEDSTC,   400     },      \
375         { AFE4404_LED3LEDENDC,  798     },      \
376         { AFE440X_ALED2STC,     480     },      \
377         { AFE440X_ALED2ENDC,    798     },      \
378         { AFE440X_ADCRSTSTCT1,  6068    },      \
379         { AFE440X_ADCRSTENDCT1, 6074    },      \
380         { AFE440X_ALED2CONVST,  6075    },      \
381         { AFE440X_ALED2CONVEND, 6534    },      \
382         { AFE440X_LED1LEDSTC,   800     },      \
383         { AFE440X_LED1LEDENDC,  1198    },      \
384         { AFE440X_LED1STC,      880     },      \
385         { AFE440X_LED1ENDC,     1198    },      \
386         { AFE440X_ADCRSTSTCT2,  6536    },      \
387         { AFE440X_ADCRSTENDCT2, 6542    },      \
388         { AFE440X_LED1CONVST,   6543    },      \
389         { AFE440X_LED1CONVEND,  7003    },      \
390         { AFE440X_ALED1STC,     1280    },      \
391         { AFE440X_ALED1ENDC,    1598    },      \
392         { AFE440X_ADCRSTSTCT3,  7005    },      \
393         { AFE440X_ADCRSTENDCT3, 7011    },      \
394         { AFE440X_ALED1CONVST,  7012    },      \
395         { AFE440X_ALED1CONVEND, 7471    },      \
396         { AFE440X_PDNCYCLESTC,  7671    },      \
397         { AFE440X_PDNCYCLEENDC, 39199   }
398
399 static const struct reg_sequence afe4404_reg_sequences[] = {
400         AFE4404_TIMING_PAIRS,
401         { AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
402         { AFE4404_TIA_GAIN_SEP, AFE440X_TIAGAIN_ENSEPGAIN },
403         { AFE440X_CONTROL2, AFE440X_CONTROL2_OSC_ENABLE },
404 };
405
406 static const struct regmap_range afe4404_yes_ranges[] = {
407         regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
408         regmap_reg_range(AFE4404_AVG_LED2_ALED2VAL, AFE4404_AVG_LED1_ALED1VAL),
409 };
410
411 static const struct regmap_access_table afe4404_volatile_table = {
412         .yes_ranges = afe4404_yes_ranges,
413         .n_yes_ranges = ARRAY_SIZE(afe4404_yes_ranges),
414 };
415
416 static const struct regmap_config afe4404_regmap_config = {
417         .reg_bits = 8,
418         .val_bits = 24,
419
420         .max_register = AFE4404_AVG_LED1_ALED1VAL,
421         .cache_type = REGCACHE_RBTREE,
422         .volatile_table = &afe4404_volatile_table,
423 };
424
425 static const struct of_device_id afe4404_of_match[] = {
426         { .compatible = "ti,afe4404", },
427         { /* sentinel */ }
428 };
429 MODULE_DEVICE_TABLE(of, afe4404_of_match);
430
431 static int __maybe_unused afe4404_suspend(struct device *dev)
432 {
433         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
434         struct afe4404_data *afe = iio_priv(indio_dev);
435         int ret;
436
437         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
438                                  AFE440X_CONTROL2_PDN_AFE,
439                                  AFE440X_CONTROL2_PDN_AFE);
440         if (ret)
441                 return ret;
442
443         ret = regulator_disable(afe->regulator);
444         if (ret) {
445                 dev_err(dev, "Unable to disable regulator\n");
446                 return ret;
447         }
448
449         return 0;
450 }
451
452 static int __maybe_unused afe4404_resume(struct device *dev)
453 {
454         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
455         struct afe4404_data *afe = iio_priv(indio_dev);
456         int ret;
457
458         ret = regulator_enable(afe->regulator);
459         if (ret) {
460                 dev_err(dev, "Unable to enable regulator\n");
461                 return ret;
462         }
463
464         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
465                                  AFE440X_CONTROL2_PDN_AFE, 0);
466         if (ret)
467                 return ret;
468
469         return 0;
470 }
471
472 static SIMPLE_DEV_PM_OPS(afe4404_pm_ops, afe4404_suspend, afe4404_resume);
473
474 static int afe4404_probe(struct i2c_client *client,
475                          const struct i2c_device_id *id)
476 {
477         struct iio_dev *indio_dev;
478         struct afe4404_data *afe;
479         int i, ret;
480
481         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*afe));
482         if (!indio_dev)
483                 return -ENOMEM;
484
485         afe = iio_priv(indio_dev);
486         i2c_set_clientdata(client, indio_dev);
487
488         afe->dev = &client->dev;
489         afe->irq = client->irq;
490
491         afe->regmap = devm_regmap_init_i2c(client, &afe4404_regmap_config);
492         if (IS_ERR(afe->regmap)) {
493                 dev_err(afe->dev, "Unable to allocate register map\n");
494                 return PTR_ERR(afe->regmap);
495         }
496
497         for (i = 0; i < F_MAX_FIELDS; i++) {
498                 afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
499                                                          afe4404_reg_fields[i]);
500                 if (IS_ERR(afe->fields[i])) {
501                         dev_err(afe->dev, "Unable to allocate regmap fields\n");
502                         return PTR_ERR(afe->fields[i]);
503                 }
504         }
505
506         afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
507         if (IS_ERR(afe->regulator)) {
508                 dev_err(afe->dev, "Unable to get regulator\n");
509                 return PTR_ERR(afe->regulator);
510         }
511         ret = regulator_enable(afe->regulator);
512         if (ret) {
513                 dev_err(afe->dev, "Unable to enable regulator\n");
514                 return ret;
515         }
516
517         ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
518                            AFE440X_CONTROL0_SW_RESET);
519         if (ret) {
520                 dev_err(afe->dev, "Unable to reset device\n");
521                 goto disable_reg;
522         }
523
524         ret = regmap_multi_reg_write(afe->regmap, afe4404_reg_sequences,
525                                      ARRAY_SIZE(afe4404_reg_sequences));
526         if (ret) {
527                 dev_err(afe->dev, "Unable to set register defaults\n");
528                 goto disable_reg;
529         }
530
531         indio_dev->modes = INDIO_DIRECT_MODE;
532         indio_dev->dev.parent = afe->dev;
533         indio_dev->channels = afe4404_channels;
534         indio_dev->num_channels = ARRAY_SIZE(afe4404_channels);
535         indio_dev->name = AFE4404_DRIVER_NAME;
536         indio_dev->info = &afe4404_iio_info;
537
538         if (afe->irq > 0) {
539                 afe->trig = devm_iio_trigger_alloc(afe->dev,
540                                                    "%s-dev%d",
541                                                    indio_dev->name,
542                                                    indio_dev->id);
543                 if (!afe->trig) {
544                         dev_err(afe->dev, "Unable to allocate IIO trigger\n");
545                         ret = -ENOMEM;
546                         goto disable_reg;
547                 }
548
549                 iio_trigger_set_drvdata(afe->trig, indio_dev);
550
551                 afe->trig->ops = &afe4404_trigger_ops;
552                 afe->trig->dev.parent = afe->dev;
553
554                 ret = iio_trigger_register(afe->trig);
555                 if (ret) {
556                         dev_err(afe->dev, "Unable to register IIO trigger\n");
557                         goto disable_reg;
558                 }
559
560                 ret = devm_request_threaded_irq(afe->dev, afe->irq,
561                                                 iio_trigger_generic_data_rdy_poll,
562                                                 NULL, IRQF_ONESHOT,
563                                                 AFE4404_DRIVER_NAME,
564                                                 afe->trig);
565                 if (ret) {
566                         dev_err(afe->dev, "Unable to request IRQ\n");
567                         goto disable_reg;
568                 }
569         }
570
571         ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
572                                          afe4404_trigger_handler, NULL);
573         if (ret) {
574                 dev_err(afe->dev, "Unable to setup buffer\n");
575                 goto unregister_trigger;
576         }
577
578         ret = iio_device_register(indio_dev);
579         if (ret) {
580                 dev_err(afe->dev, "Unable to register IIO device\n");
581                 goto unregister_triggered_buffer;
582         }
583
584         return 0;
585
586 unregister_triggered_buffer:
587         iio_triggered_buffer_cleanup(indio_dev);
588 unregister_trigger:
589         if (afe->irq > 0)
590                 iio_trigger_unregister(afe->trig);
591 disable_reg:
592         regulator_disable(afe->regulator);
593
594         return ret;
595 }
596
597 static int afe4404_remove(struct i2c_client *client)
598 {
599         struct iio_dev *indio_dev = i2c_get_clientdata(client);
600         struct afe4404_data *afe = iio_priv(indio_dev);
601         int ret;
602
603         iio_device_unregister(indio_dev);
604
605         iio_triggered_buffer_cleanup(indio_dev);
606
607         if (afe->irq > 0)
608                 iio_trigger_unregister(afe->trig);
609
610         ret = regulator_disable(afe->regulator);
611         if (ret) {
612                 dev_err(afe->dev, "Unable to disable regulator\n");
613                 return ret;
614         }
615
616         return 0;
617 }
618
619 static const struct i2c_device_id afe4404_ids[] = {
620         { "afe4404", 0 },
621         { /* sentinel */ }
622 };
623 MODULE_DEVICE_TABLE(i2c, afe4404_ids);
624
625 static struct i2c_driver afe4404_i2c_driver = {
626         .driver = {
627                 .name = AFE4404_DRIVER_NAME,
628                 .of_match_table = afe4404_of_match,
629                 .pm = &afe4404_pm_ops,
630         },
631         .probe = afe4404_probe,
632         .remove = afe4404_remove,
633         .id_table = afe4404_ids,
634 };
635 module_i2c_driver(afe4404_i2c_driver);
636
637 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
638 MODULE_DESCRIPTION("TI AFE4404 Heart Rate Monitor and Pulse Oximeter AFE");
639 MODULE_LICENSE("GPL v2");