--- /dev/null
+/*
+ * AFE4403 Heart Rate Monitors and Low-Cost Pulse Oximeters
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ *     Andrew F. Davis <afd@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "afe440x.h"
+
+#define AFE4403_DRIVER_NAME            "afe4403"
+
+/* AFE4403 Registers */
+#define AFE4403_TIAGAIN                        0x20
+#define AFE4403_TIA_AMB_GAIN           0x21
+
+/* AFE4403 GAIN register fields */
+#define AFE4403_TIAGAIN_RES_MASK       GENMASK(2, 0)
+#define AFE4403_TIAGAIN_RES_SHIFT      0
+#define AFE4403_TIAGAIN_CAP_MASK       GENMASK(7, 3)
+#define AFE4403_TIAGAIN_CAP_SHIFT      3
+
+/* AFE4403 LEDCNTRL register fields */
+#define AFE440X_LEDCNTRL_LED1_MASK             GENMASK(15, 8)
+#define AFE440X_LEDCNTRL_LED1_SHIFT            8
+#define AFE440X_LEDCNTRL_LED2_MASK             GENMASK(7, 0)
+#define AFE440X_LEDCNTRL_LED2_SHIFT            0
+#define AFE440X_LEDCNTRL_LED_RANGE_MASK                GENMASK(17, 16)
+#define AFE440X_LEDCNTRL_LED_RANGE_SHIFT       16
+
+/* AFE4403 CONTROL2 register fields */
+#define AFE440X_CONTROL2_PWR_DWN_TX    BIT(2)
+#define AFE440X_CONTROL2_EN_SLOW_DIAG  BIT(8)
+#define AFE440X_CONTROL2_DIAG_OUT_TRI  BIT(10)
+#define AFE440X_CONTROL2_TX_BRDG_MOD   BIT(11)
+#define AFE440X_CONTROL2_TX_REF_MASK   GENMASK(18, 17)
+#define AFE440X_CONTROL2_TX_REF_SHIFT  17
+
+/* AFE4404 NULL fields */
+#define NULL_MASK      0
+#define NULL_SHIFT     0
+
+/* AFE4403 LEDCNTRL values */
+#define AFE440X_LEDCNTRL_RANGE_TX_HALF 0x1
+#define AFE440X_LEDCNTRL_RANGE_TX_FULL 0x2
+#define AFE440X_LEDCNTRL_RANGE_TX_OFF  0x3
+
+/* AFE4403 CONTROL2 values */
+#define AFE440X_CONTROL2_TX_REF_025    0x0
+#define AFE440X_CONTROL2_TX_REF_050    0x1
+#define AFE440X_CONTROL2_TX_REF_100    0x2
+#define AFE440X_CONTROL2_TX_REF_075    0x3
+
+/* AFE4403 CONTROL3 values */
+#define AFE440X_CONTROL3_CLK_DIV_2     0x0
+#define AFE440X_CONTROL3_CLK_DIV_4     0x2
+#define AFE440X_CONTROL3_CLK_DIV_6     0x3
+#define AFE440X_CONTROL3_CLK_DIV_8     0x4
+#define AFE440X_CONTROL3_CLK_DIV_12    0x5
+#define AFE440X_CONTROL3_CLK_DIV_1     0x7
+
+/* AFE4403 TIAGAIN_CAP values */
+#define AFE4403_TIAGAIN_CAP_5_P                0x0
+#define AFE4403_TIAGAIN_CAP_10_P       0x1
+#define AFE4403_TIAGAIN_CAP_20_P       0x2
+#define AFE4403_TIAGAIN_CAP_30_P       0x3
+#define AFE4403_TIAGAIN_CAP_55_P       0x8
+#define AFE4403_TIAGAIN_CAP_155_P      0x10
+
+/* AFE4403 TIAGAIN_RES values */
+#define AFE4403_TIAGAIN_RES_500_K      0x0
+#define AFE4403_TIAGAIN_RES_250_K      0x1
+#define AFE4403_TIAGAIN_RES_100_K      0x2
+#define AFE4403_TIAGAIN_RES_50_K       0x3
+#define AFE4403_TIAGAIN_RES_25_K       0x4
+#define AFE4403_TIAGAIN_RES_10_K       0x5
+#define AFE4403_TIAGAIN_RES_1_M                0x6
+#define AFE4403_TIAGAIN_RES_NONE       0x7
+
+/**
+ * struct afe4403_data
+ * @dev - Device structure
+ * @spi - SPI device handle
+ * @regmap - Register map of the device
+ * @regulator - Pointer to the regulator for the IC
+ * @trig - IIO trigger for this device
+ * @irq - ADC_RDY line interrupt number
+ */
+struct afe4403_data {
+       struct device *dev;
+       struct spi_device *spi;
+       struct regmap *regmap;
+       struct regulator *regulator;
+       struct iio_trigger *trig;
+       int irq;
+};
+
+enum afe4403_chan_id {
+       LED1,
+       ALED1,
+       LED2,
+       ALED2,
+       LED1_ALED1,
+       LED2_ALED2,
+       ILED1,
+       ILED2,
+};
+
+static const struct afe440x_reg_info afe4403_reg_info[] = {
+       [LED1] = AFE440X_REG_INFO(AFE440X_LED1VAL, 0, NULL),
+       [ALED1] = AFE440X_REG_INFO(AFE440X_ALED1VAL, 0, NULL),
+       [LED2] = AFE440X_REG_INFO(AFE440X_LED2VAL, 0, NULL),
+       [ALED2] = AFE440X_REG_INFO(AFE440X_ALED2VAL, 0, NULL),
+       [LED1_ALED1] = AFE440X_REG_INFO(AFE440X_LED1_ALED1VAL, 0, NULL),
+       [LED2_ALED2] = AFE440X_REG_INFO(AFE440X_LED2_ALED2VAL, 0, NULL),
+       [ILED1] = AFE440X_REG_INFO(AFE440X_LEDCNTRL, 0, AFE440X_LEDCNTRL_LED1),
+       [ILED2] = AFE440X_REG_INFO(AFE440X_LEDCNTRL, 0, AFE440X_LEDCNTRL_LED2),
+};
+
+static const struct iio_chan_spec afe4403_channels[] = {
+       /* ADC values */
+       AFE440X_INTENSITY_CHAN(LED1, "led1", 0),
+       AFE440X_INTENSITY_CHAN(ALED1, "led1_ambient", 0),
+       AFE440X_INTENSITY_CHAN(LED2, "led2", 0),
+       AFE440X_INTENSITY_CHAN(ALED2, "led2_ambient", 0),
+       AFE440X_INTENSITY_CHAN(LED1_ALED1, "led1-led1_ambient", 0),
+       AFE440X_INTENSITY_CHAN(LED2_ALED2, "led2-led2_ambient", 0),
+       /* LED current */
+       AFE440X_CURRENT_CHAN(ILED1, "led1"),
+       AFE440X_CURRENT_CHAN(ILED2, "led2"),
+};
+
+static const struct afe440x_val_table afe4403_res_table[] = {
+       { 500000 }, { 250000 }, { 100000 }, { 50000 },
+       { 25000 }, { 10000 }, { 1000000 }, { 0 },
+};
+AFE440X_TABLE_ATTR(tia_resistance_available, afe4403_res_table);
+
+static const struct afe440x_val_table afe4403_cap_table[] = {
+       { 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
+       { 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
+       { 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
+       { 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
+       { 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
+       { 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
+       { 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
+       { 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
+};
+AFE440X_TABLE_ATTR(tia_capacitance_available, afe4403_cap_table);
+
+static ssize_t afe440x_show_register(struct device *dev,
+                                    struct device_attribute *attr,
+                                    char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
+       unsigned int reg_val, type;
+       int vals[2];
+       int ret, val_len;
+
+       ret = regmap_read(afe->regmap, afe440x_attr->reg, ®_val);
+       if (ret)
+               return ret;
+
+       reg_val &= afe440x_attr->mask;
+       reg_val >>= afe440x_attr->shift;
+
+       switch (afe440x_attr->type) {
+       case SIMPLE:
+               type = IIO_VAL_INT;
+               val_len = 1;
+               vals[0] = reg_val;
+               break;
+       case RESISTANCE:
+       case CAPACITANCE:
+               type = IIO_VAL_INT_PLUS_MICRO;
+               val_len = 2;
+               if (reg_val < afe440x_attr->table_size) {
+                       vals[0] = afe440x_attr->val_table[reg_val].integer;
+                       vals[1] = afe440x_attr->val_table[reg_val].fract;
+                       break;
+               }
+               return -EINVAL;
+       default:
+               return -EINVAL;
+       }
+
+       return iio_format_value(buf, type, val_len, vals);
+}
+
+static ssize_t afe440x_store_register(struct device *dev,
+                                     struct device_attribute *attr,
+                                     const char *buf, size_t count)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
+       int val, integer, fract, ret;
+
+       ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
+       if (ret)
+               return ret;
+
+       switch (afe440x_attr->type) {
+       case SIMPLE:
+               val = integer;
+               break;
+       case RESISTANCE:
+       case CAPACITANCE:
+               for (val = 0; val < afe440x_attr->table_size; val++)
+                       if (afe440x_attr->val_table[val].integer == integer &&
+                           afe440x_attr->val_table[val].fract == fract)
+                               break;
+               if (val == afe440x_attr->table_size)
+                       return -EINVAL;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       ret = regmap_update_bits(afe->regmap, afe440x_attr->reg,
+                                afe440x_attr->mask,
+                                (val << afe440x_attr->shift));
+       if (ret)
+               return ret;
+
+       return count;
+}
+
+static AFE440X_ATTR(tia_separate_en, AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN, SIMPLE, NULL, 0);
+
+static AFE440X_ATTR(tia_resistance1, AFE4403_TIAGAIN, AFE4403_TIAGAIN_RES, RESISTANCE, afe4403_res_table, ARRAY_SIZE(afe4403_res_table));
+static AFE440X_ATTR(tia_capacitance1, AFE4403_TIAGAIN, AFE4403_TIAGAIN_CAP, CAPACITANCE, afe4403_cap_table, ARRAY_SIZE(afe4403_cap_table));
+
+static AFE440X_ATTR(tia_resistance2, AFE4403_TIA_AMB_GAIN, AFE4403_TIAGAIN_RES, RESISTANCE, afe4403_res_table, ARRAY_SIZE(afe4403_res_table));
+static AFE440X_ATTR(tia_capacitance2, AFE4403_TIA_AMB_GAIN, AFE4403_TIAGAIN_RES, CAPACITANCE, afe4403_cap_table, ARRAY_SIZE(afe4403_cap_table));
+
+static struct attribute *afe440x_attributes[] = {
+       &afe440x_attr_tia_separate_en.dev_attr.attr,
+       &afe440x_attr_tia_resistance1.dev_attr.attr,
+       &afe440x_attr_tia_capacitance1.dev_attr.attr,
+       &afe440x_attr_tia_resistance2.dev_attr.attr,
+       &afe440x_attr_tia_capacitance2.dev_attr.attr,
+       &dev_attr_tia_resistance_available.attr,
+       &dev_attr_tia_capacitance_available.attr,
+       NULL
+};
+
+static const struct attribute_group afe440x_attribute_group = {
+       .attrs = afe440x_attributes
+};
+
+static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
+{
+       u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
+       u8 rx[3];
+       int ret;
+
+       /* Enable reading from the device */
+       ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
+       if (ret)
+               return ret;
+
+       ret = spi_write_then_read(afe->spi, ®, 1, rx, 3);
+       if (ret)
+               return ret;
+
+       *val = (rx[0] << 16) |
+               (rx[1] << 8) |
+               (rx[2]);
+
+       /* Disable reading from the device */
+       tx[3] = AFE440X_CONTROL0_WRITE;
+       ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static int afe4403_read_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int *val, int *val2, long mask)
+{
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       const struct afe440x_reg_info reg_info = afe4403_reg_info[chan->address];
+       int ret;
+
+       switch (chan->type) {
+       case IIO_INTENSITY:
+               switch (mask) {
+               case IIO_CHAN_INFO_RAW:
+                       ret = afe4403_read(afe, reg_info.reg, val);
+                       if (ret)
+                               return ret;
+                       return IIO_VAL_INT;
+               case IIO_CHAN_INFO_OFFSET:
+                       ret = regmap_read(afe->regmap, reg_info.offreg,
+                                         val);
+                       if (ret)
+                               return ret;
+                       *val &= reg_info.mask;
+                       *val >>= reg_info.shift;
+                       return IIO_VAL_INT;
+               }
+               break;
+       case IIO_CURRENT:
+               switch (mask) {
+               case IIO_CHAN_INFO_RAW:
+                       ret = regmap_read(afe->regmap, reg_info.reg, val);
+                       if (ret)
+                               return ret;
+                       *val &= reg_info.mask;
+                       *val >>= reg_info.shift;
+                       return IIO_VAL_INT;
+               case IIO_CHAN_INFO_SCALE:
+                       *val = 0;
+                       *val2 = 800000;
+                       return IIO_VAL_INT_PLUS_MICRO;
+               }
+               break;
+       default:
+               break;
+       }
+
+       return -EINVAL;
+}
+
+static int afe4403_write_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int val, int val2, long mask)
+{
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       const struct afe440x_reg_info reg_info = afe4403_reg_info[chan->address];
+
+       switch (chan->type) {
+       case IIO_INTENSITY:
+               switch (mask) {
+               case IIO_CHAN_INFO_OFFSET:
+                       return regmap_update_bits(afe->regmap,
+                               reg_info.offreg,
+                               reg_info.mask,
+                               (val << reg_info.shift));
+               }
+               break;
+       case IIO_CURRENT:
+               switch (mask) {
+               case IIO_CHAN_INFO_RAW:
+                       return regmap_update_bits(afe->regmap,
+                               reg_info.reg,
+                               reg_info.mask,
+                               (val << reg_info.shift));
+               }
+               break;
+       default:
+               break;
+       }
+
+       return -EINVAL;
+}
+
+static const struct iio_info afe4403_iio_info = {
+       .attrs = &afe440x_attribute_group,
+       .read_raw = afe4403_read_raw,
+       .write_raw = afe4403_write_raw,
+       .driver_module = THIS_MODULE,
+};
+
+static irqreturn_t afe4403_trigger_handler(int irq, void *private)
+{
+       struct iio_poll_func *pf = private;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       int ret, bit, i = 0;
+       s32 buffer[8];
+       u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
+       u8 rx[3];
+
+       /* Enable reading from the device */
+       ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
+       if (ret)
+               goto err;
+
+       for_each_set_bit(bit, indio_dev->active_scan_mask,
+                        indio_dev->masklength) {
+               ret = spi_write_then_read(afe->spi,
+                                         &afe4403_reg_info[bit].reg, 1,
+                                         rx, 3);
+               if (ret)
+                       goto err;
+
+               buffer[i++] = (rx[0] << 16) |
+                               (rx[1] << 8) |
+                               (rx[2]);
+       }
+
+       /* Disable reading from the device */
+       tx[3] = AFE440X_CONTROL0_WRITE;
+       ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
+       if (ret)
+               goto err;
+
+       iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
+err:
+       iio_trigger_notify_done(indio_dev->trig);
+
+       return IRQ_HANDLED;
+}
+
+static const struct iio_trigger_ops afe4403_trigger_ops = {
+       .owner = THIS_MODULE,
+};
+
+#define AFE4403_TIMING_PAIRS                   \
+       { AFE440X_LED2STC,      0x000050 },     \
+       { AFE440X_LED2ENDC,     0x0003e7 },     \
+       { AFE440X_LED1LEDSTC,   0x0007d0 },     \
+       { AFE440X_LED1LEDENDC,  0x000bb7 },     \
+       { AFE440X_ALED2STC,     0x000438 },     \
+       { AFE440X_ALED2ENDC,    0x0007cf },     \
+       { AFE440X_LED1STC,      0x000820 },     \
+       { AFE440X_LED1ENDC,     0x000bb7 },     \
+       { AFE440X_LED2LEDSTC,   0x000000 },     \
+       { AFE440X_LED2LEDENDC,  0x0003e7 },     \
+       { AFE440X_ALED1STC,     0x000c08 },     \
+       { AFE440X_ALED1ENDC,    0x000f9f },     \
+       { AFE440X_LED2CONVST,   0x0003ef },     \
+       { AFE440X_LED2CONVEND,  0x0007cf },     \
+       { AFE440X_ALED2CONVST,  0x0007d7 },     \
+       { AFE440X_ALED2CONVEND, 0x000bb7 },     \
+       { AFE440X_LED1CONVST,   0x000bbf },     \
+       { AFE440X_LED1CONVEND,  0x009c3f },     \
+       { AFE440X_ALED1CONVST,  0x000fa7 },     \
+       { AFE440X_ALED1CONVEND, 0x001387 },     \
+       { AFE440X_ADCRSTSTCT0,  0x0003e8 },     \
+       { AFE440X_ADCRSTENDCT0, 0x0003eb },     \
+       { AFE440X_ADCRSTSTCT1,  0x0007d0 },     \
+       { AFE440X_ADCRSTENDCT1, 0x0007d3 },     \
+       { AFE440X_ADCRSTSTCT2,  0x000bb8 },     \
+       { AFE440X_ADCRSTENDCT2, 0x000bbb },     \
+       { AFE440X_ADCRSTSTCT3,  0x000fa0 },     \
+       { AFE440X_ADCRSTENDCT3, 0x000fa3 },     \
+       { AFE440X_PRPCOUNT,     0x009c3f },     \
+       { AFE440X_PDNCYCLESTC,  0x001518 },     \
+       { AFE440X_PDNCYCLEENDC, 0x00991f }
+
+static const struct reg_sequence afe4403_reg_sequences[] = {
+       AFE4403_TIMING_PAIRS,
+       { AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN | 0x000007},
+       { AFE4403_TIA_AMB_GAIN, AFE4403_TIAGAIN_RES_1_M },
+       { AFE440X_LEDCNTRL, (0x14 << AFE440X_LEDCNTRL_LED1_SHIFT) |
+                           (0x14 << AFE440X_LEDCNTRL_LED2_SHIFT) },
+       { AFE440X_CONTROL2, AFE440X_CONTROL2_TX_REF_050 <<
+                           AFE440X_CONTROL2_TX_REF_SHIFT },
+};
+
+static const struct regmap_range afe4403_yes_ranges[] = {
+       regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
+};
+
+static const struct regmap_access_table afe4403_volatile_table = {
+       .yes_ranges = afe4403_yes_ranges,
+       .n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
+};
+
+static const struct regmap_config afe4403_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 24,
+
+       .max_register = AFE440X_PDNCYCLEENDC,
+       .cache_type = REGCACHE_RBTREE,
+       .volatile_table = &afe4403_volatile_table,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id afe4403_of_match[] = {
+       { .compatible = "ti,afe4403", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, afe4403_of_match);
+#endif
+
+static int afe4403_suspend(struct device *dev)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       int ret;
+
+       ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
+                                AFE440X_CONTROL2_PDN_AFE,
+                                AFE440X_CONTROL2_PDN_AFE);
+       if (ret)
+               return ret;
+
+       ret = regulator_disable(afe->regulator);
+       if (ret) {
+               dev_err(dev, "Unable to disable regulator\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int afe4403_resume(struct device *dev)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       int ret;
+
+       ret = regulator_enable(afe->regulator);
+       if (ret) {
+               dev_err(dev, "Unable to enable regulator\n");
+               return ret;
+       }
+
+       ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
+                                AFE440X_CONTROL2_PDN_AFE, 0);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
+
+static int afe4403_probe(struct spi_device *spi)
+{
+       struct iio_dev *indio_dev;
+       struct afe4403_data *afe;
+       int ret;
+
+       indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       afe = iio_priv(indio_dev);
+       spi_set_drvdata(spi, indio_dev);
+
+       afe->dev = &spi->dev;
+       afe->spi = spi;
+       afe->irq = spi->irq;
+
+       afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
+       if (IS_ERR(afe->regmap)) {
+               dev_err(afe->dev, "Unable to allocate register map\n");
+               return PTR_ERR(afe->regmap);
+       }
+
+       afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
+       if (IS_ERR(afe->regulator)) {
+               dev_err(afe->dev, "Unable to get regulator\n");
+               return PTR_ERR(afe->regulator);
+       }
+       ret = regulator_enable(afe->regulator);
+       if (ret) {
+               dev_err(afe->dev, "Unable to enable regulator\n");
+               return ret;
+       }
+
+       ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
+                          AFE440X_CONTROL0_SW_RESET);
+       if (ret) {
+               dev_err(afe->dev, "Unable to reset device\n");
+               goto err_disable_reg;
+       }
+
+       ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
+                                    ARRAY_SIZE(afe4403_reg_sequences));
+       if (ret) {
+               dev_err(afe->dev, "Unable to set register defaults\n");
+               goto err_disable_reg;
+       }
+
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       indio_dev->dev.parent = afe->dev;
+       indio_dev->channels = afe4403_channels;
+       indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
+       indio_dev->name = AFE4403_DRIVER_NAME;
+       indio_dev->info = &afe4403_iio_info;
+
+       if (afe->irq > 0) {
+               afe->trig = devm_iio_trigger_alloc(afe->dev,
+                                                  "%s-dev%d",
+                                                  indio_dev->name,
+                                                  indio_dev->id);
+               if (!afe->trig) {
+                       dev_err(afe->dev, "Unable to allocate IIO trigger\n");
+                       ret = -ENOMEM;
+                       goto err_disable_reg;
+               }
+
+               iio_trigger_set_drvdata(afe->trig, indio_dev);
+
+               afe->trig->ops = &afe4403_trigger_ops;
+               afe->trig->dev.parent = afe->dev;
+
+               ret = iio_trigger_register(afe->trig);
+               if (ret) {
+                       dev_err(afe->dev, "Unable to register IIO trigger\n");
+                       goto err_disable_reg;
+               }
+
+               ret = devm_request_threaded_irq(afe->dev, afe->irq,
+                                               iio_trigger_generic_data_rdy_poll,
+                                               NULL, IRQF_ONESHOT,
+                                               AFE4403_DRIVER_NAME,
+                                               afe->trig);
+               if (ret) {
+                       dev_err(afe->dev, "Unable to request IRQ\n");
+                       goto err_trig;
+               }
+       }
+
+       ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+                                        afe4403_trigger_handler, NULL);
+       if (ret) {
+               dev_err(afe->dev, "Unable to setup buffer\n");
+               goto err_trig;
+       }
+
+       ret = iio_device_register(indio_dev);
+       if (ret) {
+               dev_err(afe->dev, "Unable to register IIO device\n");
+               goto err_buff;
+       }
+
+       return 0;
+
+err_buff:
+       iio_triggered_buffer_cleanup(indio_dev);
+err_trig:
+       if (afe->irq > 0)
+               iio_trigger_unregister(afe->trig);
+err_disable_reg:
+       regulator_disable(afe->regulator);
+
+       return ret;
+}
+
+static int afe4403_remove(struct spi_device *spi)
+{
+       struct iio_dev *indio_dev = spi_get_drvdata(spi);
+       struct afe4403_data *afe = iio_priv(indio_dev);
+       int ret;
+
+       iio_device_unregister(indio_dev);
+
+       iio_triggered_buffer_cleanup(indio_dev);
+
+       if (afe->irq > 0)
+               iio_trigger_unregister(afe->trig);
+
+       ret = regulator_disable(afe->regulator);
+       if (ret) {
+               dev_err(afe->dev, "Unable to disable regulator\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static const struct spi_device_id afe4403_ids[] = {
+       { "afe4403", 0 },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, afe4403_ids);
+
+static struct spi_driver afe4403_spi_driver = {
+       .driver = {
+               .name = AFE4403_DRIVER_NAME,
+               .of_match_table = of_match_ptr(afe4403_of_match),
+               .pm = &afe4403_pm_ops,
+       },
+       .probe = afe4403_probe,
+       .remove = afe4403_remove,
+       .id_table = afe4403_ids,
+};
+module_spi_driver(afe4403_spi_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("TI AFE4403 Heart Rate and Pulse Oximeter");
+MODULE_LICENSE("GPL v2");