root/drivers/iio/dac/ad7293.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD7293 driver
 *
 * Copyright 2021 Analog Devices Inc.
 */

#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

#include <linux/unaligned.h>

#define AD7293_R1B                              BIT(16)
#define AD7293_R2B                              BIT(17)
#define AD7293_PAGE_ADDR_MSK                    GENMASK(15, 8)
#define AD7293_PAGE(x)                          FIELD_PREP(AD7293_PAGE_ADDR_MSK, x)

/* AD7293 Register Map Common */
#define AD7293_REG_NO_OP                        (AD7293_R1B | AD7293_PAGE(0x0) | 0x0)
#define AD7293_REG_PAGE_SELECT                  (AD7293_R1B | AD7293_PAGE(0x0) | 0x1)
#define AD7293_REG_CONV_CMD                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x2)
#define AD7293_REG_RESULT                       (AD7293_R1B | AD7293_PAGE(0x0) | 0x3)
#define AD7293_REG_DAC_EN                       (AD7293_R1B | AD7293_PAGE(0x0) | 0x4)
#define AD7293_REG_DEVICE_ID                    (AD7293_R2B | AD7293_PAGE(0x0) | 0xC)
#define AD7293_REG_SOFT_RESET                   (AD7293_R2B | AD7293_PAGE(0x0) | 0xF)

/* AD7293 Register Map Page 0x0 */
#define AD7293_REG_VIN0                         (AD7293_R2B | AD7293_PAGE(0x0) | 0x10)
#define AD7293_REG_VIN1                         (AD7293_R2B | AD7293_PAGE(0x0) | 0x11)
#define AD7293_REG_VIN2                         (AD7293_R2B | AD7293_PAGE(0x0) | 0x12)
#define AD7293_REG_VIN3                         (AD7293_R2B | AD7293_PAGE(0x0) | 0x13)
#define AD7293_REG_TSENSE_INT                   (AD7293_R2B | AD7293_PAGE(0x0) | 0x20)
#define AD7293_REG_TSENSE_D0                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x21)
#define AD7293_REG_TSENSE_D1                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x22)
#define AD7293_REG_ISENSE_0                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x28)
#define AD7293_REG_ISENSE_1                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x29)
#define AD7293_REG_ISENSE_2                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x2A)
#define AD7293_REG_ISENSE_3                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x2B)
#define AD7293_REG_UNI_VOUT0                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x30)
#define AD7293_REG_UNI_VOUT1                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x31)
#define AD7293_REG_UNI_VOUT2                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x32)
#define AD7293_REG_UNI_VOUT3                    (AD7293_R2B | AD7293_PAGE(0x0) | 0x33)
#define AD7293_REG_BI_VOUT0                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x34)
#define AD7293_REG_BI_VOUT1                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x35)
#define AD7293_REG_BI_VOUT2                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x36)
#define AD7293_REG_BI_VOUT3                     (AD7293_R2B | AD7293_PAGE(0x0) | 0x37)

/* AD7293 Register Map Page 0x2 */
#define AD7293_REG_DIGITAL_OUT_EN               (AD7293_R2B | AD7293_PAGE(0x2) | 0x11)
#define AD7293_REG_DIGITAL_INOUT_FUNC           (AD7293_R2B | AD7293_PAGE(0x2) | 0x12)
#define AD7293_REG_DIGITAL_FUNC_POL             (AD7293_R2B | AD7293_PAGE(0x2) | 0x13)
#define AD7293_REG_GENERAL                      (AD7293_R2B | AD7293_PAGE(0x2) | 0x14)
#define AD7293_REG_VINX_RANGE0                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x15)
#define AD7293_REG_VINX_RANGE1                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x16)
#define AD7293_REG_VINX_DIFF_SE                 (AD7293_R2B | AD7293_PAGE(0x2) | 0x17)
#define AD7293_REG_VINX_FILTER                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x18)
#define AD7293_REG_BG_EN                        (AD7293_R2B | AD7293_PAGE(0x2) | 0x19)
#define AD7293_REG_CONV_DELAY                   (AD7293_R2B | AD7293_PAGE(0x2) | 0x1A)
#define AD7293_REG_TSENSE_BG_EN                 (AD7293_R2B | AD7293_PAGE(0x2) | 0x1B)
#define AD7293_REG_ISENSE_BG_EN                 (AD7293_R2B | AD7293_PAGE(0x2) | 0x1C)
#define AD7293_REG_ISENSE_GAIN                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x1D)
#define AD7293_REG_DAC_SNOOZE_O                 (AD7293_R2B | AD7293_PAGE(0x2) | 0x1F)
#define AD7293_REG_DAC_SNOOZE_1                 (AD7293_R2B | AD7293_PAGE(0x2) | 0x20)
#define AD7293_REG_RSX_MON_BG_EN                (AD7293_R2B | AD7293_PAGE(0x2) | 0x23)
#define AD7293_REG_INTEGR_CL                    (AD7293_R2B | AD7293_PAGE(0x2) | 0x28)
#define AD7293_REG_PA_ON_CTRL                   (AD7293_R2B | AD7293_PAGE(0x2) | 0x29)
#define AD7293_REG_RAMP_TIME_0                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x2A)
#define AD7293_REG_RAMP_TIME_1                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x2B)
#define AD7293_REG_RAMP_TIME_2                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x2C)
#define AD7293_REG_RAMP_TIME_3                  (AD7293_R2B | AD7293_PAGE(0x2) | 0x2D)
#define AD7293_REG_CL_FR_IT                     (AD7293_R2B | AD7293_PAGE(0x2) | 0x2E)
#define AD7293_REG_INTX_AVSS_AVDD               (AD7293_R2B | AD7293_PAGE(0x2) | 0x2F)

/* AD7293 Register Map Page 0x3 */
#define AD7293_REG_VINX_SEQ                     (AD7293_R2B | AD7293_PAGE(0x3) | 0x10)
#define AD7293_REG_ISENSEX_TSENSEX_SEQ          (AD7293_R2B | AD7293_PAGE(0x3) | 0x11)
#define AD7293_REG_RSX_MON_BI_VOUTX_SEQ         (AD7293_R2B | AD7293_PAGE(0x3) | 0x12)

/* AD7293 Register Map Page 0xE */
#define AD7293_REG_VIN0_OFFSET                  (AD7293_R1B | AD7293_PAGE(0xE) | 0x10)
#define AD7293_REG_VIN1_OFFSET                  (AD7293_R1B | AD7293_PAGE(0xE) | 0x11)
#define AD7293_REG_VIN2_OFFSET                  (AD7293_R1B | AD7293_PAGE(0xE) | 0x12)
#define AD7293_REG_VIN3_OFFSET                  (AD7293_R1B | AD7293_PAGE(0xE) | 0x13)
#define AD7293_REG_TSENSE_INT_OFFSET            (AD7293_R1B | AD7293_PAGE(0xE) | 0x20)
#define AD7293_REG_TSENSE_D0_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x21)
#define AD7293_REG_TSENSE_D1_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x22)
#define AD7293_REG_ISENSE0_OFFSET               (AD7293_R1B | AD7293_PAGE(0xE) | 0x28)
#define AD7293_REG_ISENSE1_OFFSET               (AD7293_R1B | AD7293_PAGE(0xE) | 0x29)
#define AD7293_REG_ISENSE2_OFFSET               (AD7293_R1B | AD7293_PAGE(0xE) | 0x2A)
#define AD7293_REG_ISENSE3_OFFSET               (AD7293_R1B | AD7293_PAGE(0xE) | 0x2B)
#define AD7293_REG_UNI_VOUT0_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x30)
#define AD7293_REG_UNI_VOUT1_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x31)
#define AD7293_REG_UNI_VOUT2_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x32)
#define AD7293_REG_UNI_VOUT3_OFFSET             (AD7293_R1B | AD7293_PAGE(0xE) | 0x33)
#define AD7293_REG_BI_VOUT0_OFFSET              (AD7293_R1B | AD7293_PAGE(0xE) | 0x34)
#define AD7293_REG_BI_VOUT1_OFFSET              (AD7293_R1B | AD7293_PAGE(0xE) | 0x35)
#define AD7293_REG_BI_VOUT2_OFFSET              (AD7293_R1B | AD7293_PAGE(0xE) | 0x36)
#define AD7293_REG_BI_VOUT3_OFFSET              (AD7293_R1B | AD7293_PAGE(0xE) | 0x37)

/* AD7293 Miscellaneous Definitions */
#define AD7293_READ                             BIT(7)
#define AD7293_TRANSF_LEN_MSK                   GENMASK(17, 16)

#define AD7293_REG_ADDR_MSK                     GENMASK(7, 0)
#define AD7293_REG_VOUT_OFFSET_MSK              GENMASK(5, 4)
#define AD7293_REG_DATA_RAW_MSK                 GENMASK(15, 4)
#define AD7293_REG_VINX_RANGE_GET_CH_MSK(x, ch) (((x) >> (ch)) & 0x1)
#define AD7293_REG_VINX_RANGE_SET_CH_MSK(x, ch) (((x) & 0x1) << (ch))
#define AD7293_GENERAL_ADC_REF_MSK                      BIT(7)
#define AD7293_CHIP_ID                          0x18

enum ad7293_ch_type {
        AD7293_ADC_VINX,
        AD7293_ADC_TSENSE,
        AD7293_ADC_ISENSE,
        AD7293_DAC,
};

enum ad7293_max_offset {
        AD7293_TSENSE_MIN_OFFSET_CH = 4,
        AD7293_ISENSE_MIN_OFFSET_CH = 7,
        AD7293_VOUT_MIN_OFFSET_CH = 11,
        AD7293_VOUT_MAX_OFFSET_CH = 18,
};

static const int dac_offset_table[] = {0, 1, 2};

static const int isense_gain_table[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

static const int adc_range_table[] = {0, 1, 2, 3};

struct ad7293_state {
        struct spi_device *spi;
        /* Protect against concurrent accesses to the device, page selection and data content */
        struct mutex lock;
        struct gpio_desc *gpio_reset;
        bool vrefin_en;
        u8 page_select;
        u8 data[3] __aligned(IIO_DMA_MINALIGN);
};

static int ad7293_page_select(struct ad7293_state *st, unsigned int reg)
{
        int ret;

        if (st->page_select != FIELD_GET(AD7293_PAGE_ADDR_MSK, reg)) {
                st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, AD7293_REG_PAGE_SELECT);
                st->data[1] = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);

                ret = spi_write(st->spi, &st->data[0], 2);
                if (ret)
                        return ret;

                st->page_select = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);
        }

        return 0;
}

static int __ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
                             u16 *val)
{
        int ret;
        unsigned int length;
        struct spi_transfer t = {0};

        length = FIELD_GET(AD7293_TRANSF_LEN_MSK, reg);

        ret = ad7293_page_select(st, reg);
        if (ret)
                return ret;

        st->data[0] = AD7293_READ | FIELD_GET(AD7293_REG_ADDR_MSK, reg);
        st->data[1] = 0x0;
        st->data[2] = 0x0;

        t.tx_buf = &st->data[0];
        t.rx_buf = &st->data[0];
        t.len = length + 1;

        ret = spi_sync_transfer(st->spi, &t, 1);
        if (ret)
                return ret;

        if (length == 1)
                *val = st->data[1];
        else
                *val = get_unaligned_be16(&st->data[1]);

        return 0;
}

static int ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
                           u16 *val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __ad7293_spi_read(st, reg, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int __ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
                              u16 val)
{
        int ret;
        unsigned int length;

        length = FIELD_GET(AD7293_TRANSF_LEN_MSK, reg);

        ret = ad7293_page_select(st, reg);
        if (ret)
                return ret;

        st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, reg);

        if (length == 1)
                st->data[1] = val;
        else
                put_unaligned_be16(val, &st->data[1]);

        return spi_write(st->spi, &st->data[0], length + 1);
}

static int ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
                            u16 val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __ad7293_spi_write(st, reg, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int __ad7293_spi_update_bits(struct ad7293_state *st, unsigned int reg,
                                    u16 mask, u16 val)
{
        int ret;
        u16 data, temp;

        ret = __ad7293_spi_read(st, reg, &data);
        if (ret)
                return ret;

        temp = (data & ~mask) | (val & mask);

        return __ad7293_spi_write(st, reg, temp);
}

static int ad7293_spi_update_bits(struct ad7293_state *st, unsigned int reg,
                                  u16 mask, u16 val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __ad7293_spi_update_bits(st, reg, mask, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int ad7293_adc_get_scale(struct ad7293_state *st, unsigned int ch,
                                u16 *range)
{
        int ret;
        u16 data;

        mutex_lock(&st->lock);

        ret = __ad7293_spi_read(st, AD7293_REG_VINX_RANGE1, &data);
        if (ret)
                goto exit;

        *range = AD7293_REG_VINX_RANGE_GET_CH_MSK(data, ch);

        ret = __ad7293_spi_read(st, AD7293_REG_VINX_RANGE0, &data);
        if (ret)
                goto exit;

        *range |= AD7293_REG_VINX_RANGE_GET_CH_MSK(data, ch) << 1;

exit:
        mutex_unlock(&st->lock);

        return ret;
}

static int ad7293_adc_set_scale(struct ad7293_state *st, unsigned int ch,
                                u16 range)
{
        int ret;
        unsigned int ch_msk = BIT(ch);

        mutex_lock(&st->lock);
        ret = __ad7293_spi_update_bits(st, AD7293_REG_VINX_RANGE1, ch_msk,
                                       AD7293_REG_VINX_RANGE_SET_CH_MSK(range, ch));
        if (ret)
                goto exit;

        ret = __ad7293_spi_update_bits(st, AD7293_REG_VINX_RANGE0, ch_msk,
                                       AD7293_REG_VINX_RANGE_SET_CH_MSK((range >> 1), ch));

exit:
        mutex_unlock(&st->lock);

        return ret;
}

static int ad7293_get_offset(struct ad7293_state *st, unsigned int ch,
                             u16 *offset)
{
        if (ch < AD7293_TSENSE_MIN_OFFSET_CH)
                return ad7293_spi_read(st, AD7293_REG_VIN0_OFFSET + ch, offset);
        else if (ch < AD7293_ISENSE_MIN_OFFSET_CH)
                return ad7293_spi_read(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - 4), offset);
        else if (ch < AD7293_VOUT_MIN_OFFSET_CH)
                return ad7293_spi_read(st, AD7293_REG_ISENSE0_OFFSET + (ch - 7), offset);
        else if (ch <= AD7293_VOUT_MAX_OFFSET_CH)
                return ad7293_spi_read(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - 11), offset);

        return -EINVAL;
}

static int ad7293_set_offset(struct ad7293_state *st, unsigned int ch,
                             u16 offset)
{
        if (ch < AD7293_TSENSE_MIN_OFFSET_CH)
                return ad7293_spi_write(st, AD7293_REG_VIN0_OFFSET + ch,
                                        offset);
        else if (ch < AD7293_ISENSE_MIN_OFFSET_CH)
                return ad7293_spi_write(st,
                                        AD7293_REG_TSENSE_INT_OFFSET +
                                        (ch - AD7293_TSENSE_MIN_OFFSET_CH),
                                        offset);
        else if (ch < AD7293_VOUT_MIN_OFFSET_CH)
                return ad7293_spi_write(st,
                                        AD7293_REG_ISENSE0_OFFSET +
                                        (ch - AD7293_ISENSE_MIN_OFFSET_CH),
                                        offset);
        else if (ch <= AD7293_VOUT_MAX_OFFSET_CH)
                return ad7293_spi_update_bits(st,
                                              AD7293_REG_UNI_VOUT0_OFFSET +
                                              (ch - AD7293_VOUT_MIN_OFFSET_CH),
                                              AD7293_REG_VOUT_OFFSET_MSK,
                                              FIELD_PREP(AD7293_REG_VOUT_OFFSET_MSK, offset));

        return -EINVAL;
}

static int ad7293_isense_set_scale(struct ad7293_state *st, unsigned int ch,
                                   u16 gain)
{
        unsigned int ch_msk = (0xf << (4 * ch));

        return ad7293_spi_update_bits(st, AD7293_REG_ISENSE_GAIN, ch_msk,
                                      gain << (4 * ch));
}

static int ad7293_isense_get_scale(struct ad7293_state *st, unsigned int ch,
                                   u16 *gain)
{
        int ret;

        ret = ad7293_spi_read(st, AD7293_REG_ISENSE_GAIN, gain);
        if (ret)
                return ret;

        *gain = (*gain >> (4 * ch)) & 0xf;

        return ret;
}

static int ad7293_dac_write_raw(struct ad7293_state *st, unsigned int ch,
                                u16 raw)
{
        int ret;

        mutex_lock(&st->lock);

        ret = __ad7293_spi_update_bits(st, AD7293_REG_DAC_EN, BIT(ch), BIT(ch));
        if (ret)
                goto exit;

        ret =  __ad7293_spi_write(st, AD7293_REG_UNI_VOUT0 + ch,
                                  FIELD_PREP(AD7293_REG_DATA_RAW_MSK, raw));

exit:
        mutex_unlock(&st->lock);

        return ret;
}

static int ad7293_ch_read_raw(struct ad7293_state *st, enum ad7293_ch_type type,
                              unsigned int ch, u16 *raw)
{
        int ret;
        unsigned int reg_wr, reg_rd, data_wr;

        switch (type) {
        case AD7293_ADC_VINX:
                reg_wr = AD7293_REG_VINX_SEQ;
                reg_rd = AD7293_REG_VIN0 + ch;
                data_wr = BIT(ch);

                break;
        case AD7293_ADC_TSENSE:
                reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
                reg_rd = AD7293_REG_TSENSE_INT + ch;
                data_wr = BIT(ch);

                break;
        case AD7293_ADC_ISENSE:
                reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
                reg_rd = AD7293_REG_ISENSE_0 + ch;
                data_wr = BIT(ch) << 8;

                break;
        case AD7293_DAC:
                reg_rd = AD7293_REG_UNI_VOUT0 + ch;

                break;
        default:
                return -EINVAL;
        }

        mutex_lock(&st->lock);

        if (type != AD7293_DAC) {
                if (type == AD7293_ADC_TSENSE) {
                        ret = __ad7293_spi_write(st, AD7293_REG_TSENSE_BG_EN,
                                                 BIT(ch));
                        if (ret)
                                goto exit;

                        usleep_range(9000, 9900);
                } else if (type == AD7293_ADC_ISENSE) {
                        ret = __ad7293_spi_write(st, AD7293_REG_ISENSE_BG_EN,
                                                 BIT(ch));
                        if (ret)
                                goto exit;

                        usleep_range(2000, 7000);
                }

                ret = __ad7293_spi_write(st, reg_wr, data_wr);
                if (ret)
                        goto exit;

                ret = __ad7293_spi_write(st, AD7293_REG_CONV_CMD, 0x82);
                if (ret)
                        goto exit;
        }

        ret = __ad7293_spi_read(st, reg_rd, raw);

        *raw = FIELD_GET(AD7293_REG_DATA_RAW_MSK, *raw);

exit:
        mutex_unlock(&st->lock);

        return ret;
}

static int ad7293_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val, int *val2, long info)
{
        struct ad7293_state *st = iio_priv(indio_dev);
        int ret;
        u16 data;

        switch (info) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        if (chan->output)
                                ret =  ad7293_ch_read_raw(st, AD7293_DAC,
                                                          chan->channel, &data);
                        else
                                ret =  ad7293_ch_read_raw(st, AD7293_ADC_VINX,
                                                          chan->channel, &data);

                        break;
                case IIO_CURRENT:
                        ret =  ad7293_ch_read_raw(st, AD7293_ADC_ISENSE,
                                                  chan->channel, &data);

                        break;
                case IIO_TEMP:
                        ret =  ad7293_ch_read_raw(st, AD7293_ADC_TSENSE,
                                                  chan->channel, &data);

                        break;
                default:
                        return -EINVAL;
                }

                if (ret)
                        return ret;

                *val = data;

                return IIO_VAL_INT;
        case IIO_CHAN_INFO_OFFSET:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        if (chan->output) {
                                ret = ad7293_get_offset(st,
                                                        chan->channel + AD7293_VOUT_MIN_OFFSET_CH,
                                                        &data);

                                data = FIELD_GET(AD7293_REG_VOUT_OFFSET_MSK, data);
                        } else {
                                ret = ad7293_get_offset(st, chan->channel, &data);
                        }

                        break;
                case IIO_CURRENT:
                        ret = ad7293_get_offset(st,
                                                chan->channel + AD7293_ISENSE_MIN_OFFSET_CH,
                                                &data);

                        break;
                case IIO_TEMP:
                        ret = ad7293_get_offset(st,
                                                chan->channel + AD7293_TSENSE_MIN_OFFSET_CH,
                                                &data);

                        break;
                default:
                        return -EINVAL;
                }
                if (ret)
                        return ret;

                *val = data;

                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        ret = ad7293_adc_get_scale(st, chan->channel, &data);
                        if (ret)
                                return ret;

                        *val = data;

                        return IIO_VAL_INT;
                case IIO_CURRENT:
                        ret = ad7293_isense_get_scale(st, chan->channel, &data);
                        if (ret)
                                return ret;

                        *val = data;

                        return IIO_VAL_INT;
                case IIO_TEMP:
                        *val = 1;
                        *val2 = 8;

                        return IIO_VAL_FRACTIONAL;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

static int ad7293_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long info)
{
        struct ad7293_state *st = iio_priv(indio_dev);

        switch (info) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        if (!chan->output)
                                return -EINVAL;

                        return ad7293_dac_write_raw(st, chan->channel, val);
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_OFFSET:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        if (chan->output)
                                return ad7293_set_offset(st,
                                                         chan->channel +
                                                         AD7293_VOUT_MIN_OFFSET_CH,
                                                         val);
                        else
                                return ad7293_set_offset(st, chan->channel, val);
                case IIO_CURRENT:
                        return ad7293_set_offset(st,
                                                 chan->channel +
                                                 AD7293_ISENSE_MIN_OFFSET_CH,
                                                 val);
                case IIO_TEMP:
                        return ad7293_set_offset(st,
                                                 chan->channel +
                                                 AD7293_TSENSE_MIN_OFFSET_CH,
                                                 val);
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        return ad7293_adc_set_scale(st, chan->channel, val);
                case IIO_CURRENT:
                        return ad7293_isense_set_scale(st, chan->channel, val);
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

static int ad7293_reg_access(struct iio_dev *indio_dev,
                             unsigned int reg,
                             unsigned int write_val,
                             unsigned int *read_val)
{
        struct ad7293_state *st = iio_priv(indio_dev);
        int ret;

        if (read_val) {
                u16 temp;
                ret = ad7293_spi_read(st, reg, &temp);
                *read_val = temp;
        } else {
                ret = ad7293_spi_write(st, reg, (u16)write_val);
        }

        return ret;
}

static int ad7293_read_avail(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             const int **vals, int *type, int *length,
                             long info)
{
        switch (info) {
        case IIO_CHAN_INFO_OFFSET:
                *vals = dac_offset_table;
                *type = IIO_VAL_INT;
                *length = ARRAY_SIZE(dac_offset_table);

                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_SCALE:
                *type = IIO_VAL_INT;

                switch (chan->type) {
                case IIO_VOLTAGE:
                        *vals = adc_range_table;
                        *length = ARRAY_SIZE(adc_range_table);
                        return IIO_AVAIL_LIST;
                case IIO_CURRENT:
                        *vals = isense_gain_table;
                        *length = ARRAY_SIZE(isense_gain_table);
                        return IIO_AVAIL_LIST;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

#define AD7293_CHAN_ADC(_channel) {                                     \
        .type = IIO_VOLTAGE,                                            \
        .output = 0,                                                    \
        .indexed = 1,                                                   \
        .channel = _channel,                                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
                              BIT(IIO_CHAN_INFO_SCALE) |                \
                              BIT(IIO_CHAN_INFO_OFFSET),                \
        .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE)  \
}

#define AD7293_CHAN_DAC(_channel) {                                     \
        .type = IIO_VOLTAGE,                                            \
        .output = 1,                                                    \
        .indexed = 1,                                                   \
        .channel = _channel,                                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
                              BIT(IIO_CHAN_INFO_OFFSET),                \
        .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_OFFSET) \
}

#define AD7293_CHAN_ISENSE(_channel) {                                  \
        .type = IIO_CURRENT,                                            \
        .output = 0,                                                    \
        .indexed = 1,                                                   \
        .channel = _channel,                                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
                              BIT(IIO_CHAN_INFO_OFFSET) |               \
                              BIT(IIO_CHAN_INFO_SCALE),                 \
        .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE)  \
}

#define AD7293_CHAN_TEMP(_channel) {                                    \
        .type = IIO_TEMP,                                               \
        .output = 0,                                                    \
        .indexed = 1,                                                   \
        .channel = _channel,                                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
                              BIT(IIO_CHAN_INFO_OFFSET),                \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)            \
}

static const struct iio_chan_spec ad7293_channels[] = {
        AD7293_CHAN_ADC(0),
        AD7293_CHAN_ADC(1),
        AD7293_CHAN_ADC(2),
        AD7293_CHAN_ADC(3),
        AD7293_CHAN_ISENSE(0),
        AD7293_CHAN_ISENSE(1),
        AD7293_CHAN_ISENSE(2),
        AD7293_CHAN_ISENSE(3),
        AD7293_CHAN_TEMP(0),
        AD7293_CHAN_TEMP(1),
        AD7293_CHAN_TEMP(2),
        AD7293_CHAN_DAC(0),
        AD7293_CHAN_DAC(1),
        AD7293_CHAN_DAC(2),
        AD7293_CHAN_DAC(3),
        AD7293_CHAN_DAC(4),
        AD7293_CHAN_DAC(5),
        AD7293_CHAN_DAC(6),
        AD7293_CHAN_DAC(7)
};

static int ad7293_soft_reset(struct ad7293_state *st)
{
        int ret;

        ret = __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x7293);
        if (ret)
                return ret;

        return __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x0000);
}

static int ad7293_reset(struct ad7293_state *st)
{
        if (st->gpio_reset) {
                gpiod_set_value(st->gpio_reset, 0);
                usleep_range(100, 1000);
                gpiod_set_value(st->gpio_reset, 1);
                usleep_range(100, 1000);

                return 0;
        }

        /* Perform a software reset */
        return ad7293_soft_reset(st);
}

static int ad7293_properties_parse(struct ad7293_state *st)
{
        struct spi_device *spi = st->spi;
        int ret;

        ret = devm_regulator_get_enable(&spi->dev, "avdd");
        if (ret)
                return dev_err_probe(&spi->dev, ret, "failed to enable AVDD\n");

        ret = devm_regulator_get_enable(&spi->dev, "vdrive");
        if (ret)
                return dev_err_probe(&spi->dev, ret, "failed to enable VDRIVE\n");

        ret = devm_regulator_get_enable_optional(&spi->dev, "vrefin");
        if (ret < 0 && ret != -ENODEV)
                return dev_err_probe(&spi->dev, ret, "failed to enable VREFIN\n");

        st->vrefin_en = ret != -ENODEV;

        st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
                                                 GPIOD_OUT_HIGH);
        if (IS_ERR(st->gpio_reset))
                return dev_err_probe(&spi->dev, PTR_ERR(st->gpio_reset),
                                     "failed to get the reset GPIO\n");

        return 0;
}

static int ad7293_init(struct ad7293_state *st)
{
        int ret;
        u16 chip_id;
        struct spi_device *spi = st->spi;

        ret = ad7293_properties_parse(st);
        if (ret)
                return ret;

        ret = ad7293_reset(st);
        if (ret)
                return ret;

        /* Check Chip ID */
        ret = __ad7293_spi_read(st, AD7293_REG_DEVICE_ID, &chip_id);
        if (ret)
                return ret;

        if (chip_id != AD7293_CHIP_ID) {
                dev_err(&spi->dev, "Invalid Chip ID.\n");
                return -EINVAL;
        }

        if (!st->vrefin_en)
                return __ad7293_spi_update_bits(st, AD7293_REG_GENERAL,
                                                AD7293_GENERAL_ADC_REF_MSK,
                                                AD7293_GENERAL_ADC_REF_MSK);

        return 0;
}

static const struct iio_info ad7293_info = {
        .read_raw = ad7293_read_raw,
        .write_raw = ad7293_write_raw,
        .read_avail = &ad7293_read_avail,
        .debugfs_reg_access = &ad7293_reg_access,
};

static int ad7293_probe(struct spi_device *spi)
{
        struct iio_dev *indio_dev;
        struct ad7293_state *st;
        int ret;

        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
        if (!indio_dev)
                return -ENOMEM;

        st = iio_priv(indio_dev);

        indio_dev->info = &ad7293_info;
        indio_dev->name = "ad7293";
        indio_dev->channels = ad7293_channels;
        indio_dev->num_channels = ARRAY_SIZE(ad7293_channels);

        st->spi = spi;
        st->page_select = 0;

        mutex_init(&st->lock);

        ret = ad7293_init(st);
        if (ret)
                return ret;

        return devm_iio_device_register(&spi->dev, indio_dev);
}

static const struct spi_device_id ad7293_id[] = {
        { "ad7293", 0 },
        { }
};
MODULE_DEVICE_TABLE(spi, ad7293_id);

static const struct of_device_id ad7293_of_match[] = {
        { .compatible = "adi,ad7293" },
        { }
};
MODULE_DEVICE_TABLE(of, ad7293_of_match);

static struct spi_driver ad7293_driver = {
        .driver = {
                .name = "ad7293",
                .of_match_table = ad7293_of_match,
        },
        .probe = ad7293_probe,
        .id_table = ad7293_id,
};
module_spi_driver(ad7293_driver);

MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
MODULE_DESCRIPTION("Analog Devices AD7293");
MODULE_LICENSE("GPL v2");