drivers/iio/health/afe4403.c

   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 enum afe4403_fields {
  43         /* Gains */
  44         F_RF_LED1, F_CF_LED1,
  45         F_RF_LED, F_CF_LED,
  46
  47         /* LED Current */
  48         F_ILED1, F_ILED2,
  49
  50         /* sentinel */
  51         F_MAX_FIELDS
  52 };
  53
  54 static const struct reg_field afe4403_reg_fields[] = {
  55         /* Gains */
  56         [F_RF_LED1]     = REG_FIELD(AFE4403_TIAGAIN, 0, 2),
  57         [F_CF_LED1]     = REG_FIELD(AFE4403_TIAGAIN, 3, 7),
  58         [F_RF_LED]      = REG_FIELD(AFE4403_TIA_AMB_GAIN, 0, 2),
  59         [F_CF_LED]      = REG_FIELD(AFE4403_TIA_AMB_GAIN, 3, 7),
  60         /* LED Current */
  61         [F_ILED1]       = REG_FIELD(AFE440X_LEDCNTRL, 0, 7),
  62         [F_ILED2]       = REG_FIELD(AFE440X_LEDCNTRL, 8, 15),
  63 };
  64
  65 /**
  66  * struct afe4403_data - AFE4403 device instance data
  67  * @dev: Device structure
  68  * @spi: SPI device handle
  69  * @regmap: Register map of the device
  70  * @fields: Register fields of the device
  71  * @regulator: Pointer to the regulator for the IC
  72  * @trig: IIO trigger for this device
  73  * @irq: ADC_RDY line interrupt number
  74  * @buffer: Used to construct data layout to push into IIO buffer.
  75  */
  76 struct afe4403_data {
  77         struct device *dev;
  78         struct spi_device *spi;
  79         struct regmap *regmap;
  80         struct regmap_field *fields[F_MAX_FIELDS];
  81         struct regulator *regulator;
  82         struct iio_trigger *trig;
  83         int irq;
  84         /* Ensure suitable alignment for timestamp */
  85         s32 buffer[8] __aligned(8);
  86 };
  87
  88 enum afe4403_chan_id {
  89         LED2 = 1,
  90         ALED2,
  91         LED1,
  92         ALED1,
  93         LED2_ALED2,
  94         LED1_ALED1,
  95 };
  96
  97 static const unsigned int afe4403_channel_values[] = {
  98         [LED2] = AFE440X_LED2VAL,
  99         [ALED2] = AFE440X_ALED2VAL,
 100         [LED1] = AFE440X_LED1VAL,
 101         [ALED1] = AFE440X_ALED1VAL,
 102         [LED2_ALED2] = AFE440X_LED2_ALED2VAL,
 103         [LED1_ALED1] = AFE440X_LED1_ALED1VAL,
 104 };
 105
 106 static const unsigned int afe4403_channel_leds[] = {
 107         [LED2] = F_ILED2,
 108         [LED1] = F_ILED1,
 109 };
 110
 111 static const struct iio_chan_spec afe4403_channels[] = {
 112         /* ADC values */
 113         AFE440X_INTENSITY_CHAN(LED2, 0),
 114         AFE440X_INTENSITY_CHAN(ALED2, 0),
 115         AFE440X_INTENSITY_CHAN(LED1, 0),
 116         AFE440X_INTENSITY_CHAN(ALED1, 0),
 117         AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
 118         AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
 119         /* LED current */
 120         AFE440X_CURRENT_CHAN(LED2),
 121         AFE440X_CURRENT_CHAN(LED1),
 122 };
 123
 124 static const struct afe440x_val_table afe4403_res_table[] = {
 125         { 500000 }, { 250000 }, { 100000 }, { 50000 },
 126         { 25000 }, { 10000 }, { 1000000 }, { 0 },
 127 };
 128 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4403_res_table);
 129
 130 static const struct afe440x_val_table afe4403_cap_table[] = {
 131         { 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
 132         { 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
 133         { 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
 134         { 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
 135         { 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
 136         { 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
 137         { 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
 138         { 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
 139 };
 140 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4403_cap_table);
 141
 142 static ssize_t afe440x_show_register(struct device *dev,
 143                                      struct device_attribute *attr,
 144                                      char *buf)
 145 {
 146         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 147         struct afe4403_data *afe = iio_priv(indio_dev);
 148         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 149         unsigned int reg_val;
 150         int vals[2];
 151         int ret;
 152
 153         ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
 154         if (ret)
 155                 return ret;
 156
 157         if (reg_val >= afe440x_attr->table_size)
 158                 return -EINVAL;
 159
 160         vals[0] = afe440x_attr->val_table[reg_val].integer;
 161         vals[1] = afe440x_attr->val_table[reg_val].fract;
 162
 163         return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
 164 }
 165
 166 static ssize_t afe440x_store_register(struct device *dev,
 167                                       struct device_attribute *attr,
 168                                       const char *buf, size_t count)
 169 {
 170         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 171         struct afe4403_data *afe = iio_priv(indio_dev);
 172         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 173         int val, integer, fract, ret;
 174
 175         ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
 176         if (ret)
 177                 return ret;
 178
 179         for (val = 0; val < afe440x_attr->table_size; val++)
 180                 if (afe440x_attr->val_table[val].integer == integer &&
 181                     afe440x_attr->val_table[val].fract == fract)
 182                         break;
 183         if (val == afe440x_attr->table_size)
 184                 return -EINVAL;
 185
 186         ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
 187         if (ret)
 188                 return ret;
 189
 190         return count;
 191 }
 192
 193 static AFE440X_ATTR(in_intensity1_resistance, F_RF_LED, afe4403_res_table);
 194 static AFE440X_ATTR(in_intensity1_capacitance, F_CF_LED, afe4403_cap_table);
 195
 196 static AFE440X_ATTR(in_intensity2_resistance, F_RF_LED, afe4403_res_table);
 197 static AFE440X_ATTR(in_intensity2_capacitance, F_CF_LED, afe4403_cap_table);
 198
 199 static AFE440X_ATTR(in_intensity3_resistance, F_RF_LED1, afe4403_res_table);
 200 static AFE440X_ATTR(in_intensity3_capacitance, F_CF_LED1, afe4403_cap_table);
 201
 202 static AFE440X_ATTR(in_intensity4_resistance, F_RF_LED1, afe4403_res_table);
 203 static AFE440X_ATTR(in_intensity4_capacitance, F_CF_LED1, afe4403_cap_table);
 204
 205 static struct attribute *afe440x_attributes[] = {
 206         &dev_attr_in_intensity_resistance_available.attr,
 207         &dev_attr_in_intensity_capacitance_available.attr,
 208         &afe440x_attr_in_intensity1_resistance.dev_attr.attr,
 209         &afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
 210         &afe440x_attr_in_intensity2_resistance.dev_attr.attr,
 211         &afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
 212         &afe440x_attr_in_intensity3_resistance.dev_attr.attr,
 213         &afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
 214         &afe440x_attr_in_intensity4_resistance.dev_attr.attr,
 215         &afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
 216         NULL
 217 };
 218
 219 static const struct attribute_group afe440x_attribute_group = {
 220         .attrs = afe440x_attributes
 221 };
 222
 223 static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
 224 {
 225         u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
 226         u8 rx[3];
 227         int ret;
 228
 229         /* Enable reading from the device */
 230         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 231         if (ret)
 232                 return ret;
 233
 234         ret = spi_write_then_read(afe->spi, &reg, 1, rx, 3);
 235         if (ret)
 236                 return ret;
 237
 238         *val = (rx[0] << 16) |
 239                 (rx[1] << 8) |
 240                 (rx[2]);
 241
 242         /* Disable reading from the device */
 243         tx[3] = AFE440X_CONTROL0_WRITE;
 244         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 245         if (ret)
 246                 return ret;
 247
 248         return 0;
 249 }
 250
 251 static int afe4403_read_raw(struct iio_dev *indio_dev,
 252                             struct iio_chan_spec const *chan,
 253                             int *val, int *val2, long mask)
 254 {
 255         struct afe4403_data *afe = iio_priv(indio_dev);
 256         unsigned int reg = afe4403_channel_values[chan->address];
 257         unsigned int field = afe4403_channel_leds[chan->address];
 258         int ret;
 259
 260         switch (chan->type) {
 261         case IIO_INTENSITY:
 262                 switch (mask) {
 263                 case IIO_CHAN_INFO_RAW:
 264                         ret = afe4403_read(afe, reg, val);
 265                         if (ret)
 266                                 return ret;
 267                         return IIO_VAL_INT;
 268                 }
 269                 break;
 270         case IIO_CURRENT:
 271                 switch (mask) {
 272                 case IIO_CHAN_INFO_RAW:
 273                         ret = regmap_field_read(afe->fields[field], val);
 274                         if (ret)
 275                                 return ret;
 276                         return IIO_VAL_INT;
 277                 case IIO_CHAN_INFO_SCALE:
 278                         *val = 0;
 279                         *val2 = 800000;
 280                         return IIO_VAL_INT_PLUS_MICRO;
 281                 }
 282                 break;
 283         default:
 284                 break;
 285         }
 286
 287         return -EINVAL;
 288 }
 289
 290 static int afe4403_write_raw(struct iio_dev *indio_dev,
 291                              struct iio_chan_spec const *chan,
 292                              int val, int val2, long mask)
 293 {
 294         struct afe4403_data *afe = iio_priv(indio_dev);
 295         unsigned int field = afe4403_channel_leds[chan->address];
 296
 297         switch (chan->type) {
 298         case IIO_CURRENT:
 299                 switch (mask) {
 300                 case IIO_CHAN_INFO_RAW:
 301                         return regmap_field_write(afe->fields[field], val);
 302                 }
 303                 break;
 304         default:
 305                 break;
 306         }
 307
 308         return -EINVAL;
 309 }
 310
 311 static const struct iio_info afe4403_iio_info = {
 312         .attrs = &afe440x_attribute_group,
 313         .read_raw = afe4403_read_raw,
 314         .write_raw = afe4403_write_raw,
 315 };
 316
 317 static irqreturn_t afe4403_trigger_handler(int irq, void *private)
 318 {
 319         struct iio_poll_func *pf = private;
 320         struct iio_dev *indio_dev = pf->indio_dev;
 321         struct afe4403_data *afe = iio_priv(indio_dev);
 322         int ret, bit, i = 0;
 323         u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
 324         u8 rx[3];
 325
 326         /* Enable reading from the device */
 327         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 328         if (ret)
 329                 goto err;
 330
 331         for_each_set_bit(bit, indio_dev->active_scan_mask,
 332                          indio_dev->masklength) {
 333                 ret = spi_write_then_read(afe->spi,
 334                                           &afe4403_channel_values[bit], 1,
 335                                           rx, 3);
 336                 if (ret)
 337                         goto err;
 338
 339                 afe->buffer[i++] = (rx[0] << 16) |
 340                                    (rx[1] << 8) |
 341                                    (rx[2]);
 342         }
 343
 344         /* Disable reading from the device */
 345         tx[3] = AFE440X_CONTROL0_WRITE;
 346         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 347         if (ret)
 348                 goto err;
 349
 350         iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
 351                                            pf->timestamp);
 352 err:
 353         iio_trigger_notify_done(indio_dev->trig);
 354
 355         return IRQ_HANDLED;
 356 }
 357
 358 static const struct iio_trigger_ops afe4403_trigger_ops = {
 359 };
 360
 361 #define AFE4403_TIMING_PAIRS                    \
 362         { AFE440X_LED2STC,      0x000050 },     \
 363         { AFE440X_LED2ENDC,     0x0003e7 },     \
 364         { AFE440X_LED1LEDSTC,   0x0007d0 },     \
 365         { AFE440X_LED1LEDENDC,  0x000bb7 },     \
 366         { AFE440X_ALED2STC,     0x000438 },     \
 367         { AFE440X_ALED2ENDC,    0x0007cf },     \
 368         { AFE440X_LED1STC,      0x000820 },     \
 369         { AFE440X_LED1ENDC,     0x000bb7 },     \
 370         { AFE440X_LED2LEDSTC,   0x000000 },     \
 371         { AFE440X_LED2LEDENDC,  0x0003e7 },     \
 372         { AFE440X_ALED1STC,     0x000c08 },     \
 373         { AFE440X_ALED1ENDC,    0x000f9f },     \
 374         { AFE440X_LED2CONVST,   0x0003ef },     \
 375         { AFE440X_LED2CONVEND,  0x0007cf },     \
 376         { AFE440X_ALED2CONVST,  0x0007d7 },     \
 377         { AFE440X_ALED2CONVEND, 0x000bb7 },     \
 378         { AFE440X_LED1CONVST,   0x000bbf },     \
 379         { AFE440X_LED1CONVEND,  0x009c3f },     \
 380         { AFE440X_ALED1CONVST,  0x000fa7 },     \
 381         { AFE440X_ALED1CONVEND, 0x001387 },     \
 382         { AFE440X_ADCRSTSTCT0,  0x0003e8 },     \
 383         { AFE440X_ADCRSTENDCT0, 0x0003eb },     \
 384         { AFE440X_ADCRSTSTCT1,  0x0007d0 },     \
 385         { AFE440X_ADCRSTENDCT1, 0x0007d3 },     \
 386         { AFE440X_ADCRSTSTCT2,  0x000bb8 },     \
 387         { AFE440X_ADCRSTENDCT2, 0x000bbb },     \
 388         { AFE440X_ADCRSTSTCT3,  0x000fa0 },     \
 389         { AFE440X_ADCRSTENDCT3, 0x000fa3 },     \
 390         { AFE440X_PRPCOUNT,     0x009c3f },     \
 391         { AFE440X_PDNCYCLESTC,  0x001518 },     \
 392         { AFE440X_PDNCYCLEENDC, 0x00991f }
 393
 394 static const struct reg_sequence afe4403_reg_sequences[] = {
 395         AFE4403_TIMING_PAIRS,
 396         { AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
 397         { AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
 398 };
 399
 400 static const struct regmap_range afe4403_yes_ranges[] = {
 401         regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
 402 };
 403
 404 static const struct regmap_access_table afe4403_volatile_table = {
 405         .yes_ranges = afe4403_yes_ranges,
 406         .n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
 407 };
 408
 409 static const struct regmap_config afe4403_regmap_config = {
 410         .reg_bits = 8,
 411         .val_bits = 24,
 412
 413         .max_register = AFE440X_PDNCYCLEENDC,
 414         .cache_type = REGCACHE_RBTREE,
 415         .volatile_table = &afe4403_volatile_table,
 416 };
 417
 418 static const struct of_device_id afe4403_of_match[] = {
 419         { .compatible = "ti,afe4403", },
 420         { /* sentinel */ }
 421 };
 422 MODULE_DEVICE_TABLE(of, afe4403_of_match);
 423
 424 static int __maybe_unused afe4403_suspend(struct device *dev)
 425 {
 426         struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
 427         struct afe4403_data *afe = iio_priv(indio_dev);
 428         int ret;
 429
 430         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 431                                  AFE440X_CONTROL2_PDN_AFE,
 432                                  AFE440X_CONTROL2_PDN_AFE);
 433         if (ret)
 434                 return ret;
 435
 436         ret = regulator_disable(afe->regulator);
 437         if (ret) {
 438                 dev_err(dev, "Unable to disable regulator\n");
 439                 return ret;
 440         }
 441
 442         return 0;
 443 }
 444
 445 static int __maybe_unused afe4403_resume(struct device *dev)
 446 {
 447         struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
 448         struct afe4403_data *afe = iio_priv(indio_dev);
 449         int ret;
 450
 451         ret = regulator_enable(afe->regulator);
 452         if (ret) {
 453                 dev_err(dev, "Unable to enable regulator\n");
 454                 return ret;
 455         }
 456
 457         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 458                                  AFE440X_CONTROL2_PDN_AFE, 0);
 459         if (ret)
 460                 return ret;
 461
 462         return 0;
 463 }
 464
 465 static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
 466
 467 static int afe4403_probe(struct spi_device *spi)
 468 {
 469         struct iio_dev *indio_dev;
 470         struct afe4403_data *afe;
 471         int i, ret;
 472
 473         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
 474         if (!indio_dev)
 475                 return -ENOMEM;
 476
 477         afe = iio_priv(indio_dev);
 478         spi_set_drvdata(spi, indio_dev);
 479
 480         afe->dev = &spi->dev;
 481         afe->spi = spi;
 482         afe->irq = spi->irq;
 483
 484         afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
 485         if (IS_ERR(afe->regmap)) {
 486                 dev_err(afe->dev, "Unable to allocate register map\n");
 487                 return PTR_ERR(afe->regmap);
 488         }
 489
 490         for (i = 0; i < F_MAX_FIELDS; i++) {
 491                 afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
 492                                                          afe4403_reg_fields[i]);
 493                 if (IS_ERR(afe->fields[i])) {
 494                         dev_err(afe->dev, "Unable to allocate regmap fields\n");
 495                         return PTR_ERR(afe->fields[i]);
 496                 }
 497         }
 498
 499         afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
 500         if (IS_ERR(afe->regulator)) {
 501                 dev_err(afe->dev, "Unable to get regulator\n");
 502                 return PTR_ERR(afe->regulator);
 503         }
 504         ret = regulator_enable(afe->regulator);
 505         if (ret) {
 506                 dev_err(afe->dev, "Unable to enable regulator\n");
 507                 return ret;
 508         }
 509
 510         ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
 511                            AFE440X_CONTROL0_SW_RESET);
 512         if (ret) {
 513                 dev_err(afe->dev, "Unable to reset device\n");
 514                 goto err_disable_reg;
 515         }
 516
 517         ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
 518                                      ARRAY_SIZE(afe4403_reg_sequences));
 519         if (ret) {
 520                 dev_err(afe->dev, "Unable to set register defaults\n");
 521                 goto err_disable_reg;
 522         }
 523
 524         indio_dev->modes = INDIO_DIRECT_MODE;
 525         indio_dev->dev.parent = afe->dev;
 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                                                    indio_dev->id);
 536                 if (!afe->trig) {
 537                         dev_err(afe->dev, "Unable to allocate IIO trigger\n");
 538                         ret = -ENOMEM;
 539                         goto err_disable_reg;
 540                 }
 541
 542                 iio_trigger_set_drvdata(afe->trig, indio_dev);
 543
 544                 afe->trig->ops = &afe4403_trigger_ops;
 545                 afe->trig->dev.parent = afe->dev;
 546
 547                 ret = iio_trigger_register(afe->trig);
 548                 if (ret) {
 549                         dev_err(afe->dev, "Unable to register IIO trigger\n");
 550                         goto err_disable_reg;
 551                 }
 552
 553                 ret = devm_request_threaded_irq(afe->dev, afe->irq,
 554                                                 iio_trigger_generic_data_rdy_poll,
 555                                                 NULL, IRQF_ONESHOT,
 556                                                 AFE4403_DRIVER_NAME,
 557                                                 afe->trig);
 558                 if (ret) {
 559                         dev_err(afe->dev, "Unable to request IRQ\n");
 560                         goto err_trig;
 561                 }
 562         }
 563
 564         ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 565                                          afe4403_trigger_handler, NULL);
 566         if (ret) {
 567                 dev_err(afe->dev, "Unable to setup buffer\n");
 568                 goto err_trig;
 569         }
 570
 571         ret = iio_device_register(indio_dev);
 572         if (ret) {
 573                 dev_err(afe->dev, "Unable to register IIO device\n");
 574                 goto err_buff;
 575         }
 576
 577         return 0;
 578
 579 err_buff:
 580         iio_triggered_buffer_cleanup(indio_dev);
 581 err_trig:
 582         if (afe->irq > 0)
 583                 iio_trigger_unregister(afe->trig);
 584 err_disable_reg:
 585         regulator_disable(afe->regulator);
 586
 587         return ret;
 588 }
 589
 590 static int afe4403_remove(struct spi_device *spi)
 591 {
 592         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 593         struct afe4403_data *afe = iio_priv(indio_dev);
 594         int ret;
 595
 596         iio_device_unregister(indio_dev);
 597
 598         iio_triggered_buffer_cleanup(indio_dev);
 599
 600         if (afe->irq > 0)
 601                 iio_trigger_unregister(afe->trig);
 602
 603         ret = regulator_disable(afe->regulator);
 604         if (ret) {
 605                 dev_err(afe->dev, "Unable to disable regulator\n");
 606                 return ret;
 607         }
 608
 609         return 0;
 610 }
 611
 612 static const struct spi_device_id afe4403_ids[] = {
 613         { "afe4403", 0 },
 614         { /* sentinel */ }
 615 };
 616 MODULE_DEVICE_TABLE(spi, afe4403_ids);
 617
 618 static struct spi_driver afe4403_spi_driver = {
 619         .driver = {
 620                 .name = AFE4403_DRIVER_NAME,
 621                 .of_match_table = afe4403_of_match,
 622                 .pm = &afe4403_pm_ops,
 623         },
 624         .probe = afe4403_probe,
 625         .remove = afe4403_remove,
 626         .id_table = afe4403_ids,
 627 };
 628 module_spi_driver(afe4403_spi_driver);
 629
 630 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
 631 MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
 632 MODULE_LICENSE("GPL v2");