root/drivers/iio/frequency/adrf6780.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ADRF6780 driver
 *
 * Copyright 2021 Analog Devices Inc.
 */

#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/spi/spi.h>

#include <linux/unaligned.h>

/* ADRF6780 Register Map */
#define ADRF6780_REG_CONTROL                    0x00
#define ADRF6780_REG_ALARM_READBACK             0x01
#define ADRF6780_REG_ALARM_MASKS                0x02
#define ADRF6780_REG_ENABLE                     0x03
#define ADRF6780_REG_LINEARIZE                  0x04
#define ADRF6780_REG_LO_PATH                    0x05
#define ADRF6780_REG_ADC_CONTROL                0x06
#define ADRF6780_REG_ADC_OUTPUT                 0x0C

/* ADRF6780_REG_CONTROL Map */
#define ADRF6780_PARITY_EN_MSK                  BIT(15)
#define ADRF6780_SOFT_RESET_MSK                 BIT(14)
#define ADRF6780_CHIP_ID_MSK                    GENMASK(11, 4)
#define ADRF6780_CHIP_ID                        0xA
#define ADRF6780_CHIP_REVISION_MSK              GENMASK(3, 0)

/* ADRF6780_REG_ALARM_READBACK Map */
#define ADRF6780_PARITY_ERROR_MSK               BIT(15)
#define ADRF6780_TOO_FEW_ERRORS_MSK             BIT(14)
#define ADRF6780_TOO_MANY_ERRORS_MSK            BIT(13)
#define ADRF6780_ADDRESS_RANGE_ERROR_MSK        BIT(12)

/* ADRF6780_REG_ENABLE Map */
#define ADRF6780_VGA_BUFFER_EN_MSK              BIT(8)
#define ADRF6780_DETECTOR_EN_MSK                BIT(7)
#define ADRF6780_LO_BUFFER_EN_MSK               BIT(6)
#define ADRF6780_IF_MODE_EN_MSK                 BIT(5)
#define ADRF6780_IQ_MODE_EN_MSK                 BIT(4)
#define ADRF6780_LO_X2_EN_MSK                   BIT(3)
#define ADRF6780_LO_PPF_EN_MSK                  BIT(2)
#define ADRF6780_LO_EN_MSK                      BIT(1)
#define ADRF6780_UC_BIAS_EN_MSK                 BIT(0)

/* ADRF6780_REG_LINEARIZE Map */
#define ADRF6780_RDAC_LINEARIZE_MSK             GENMASK(7, 0)

/* ADRF6780_REG_LO_PATH Map */
#define ADRF6780_LO_SIDEBAND_MSK                BIT(10)
#define ADRF6780_Q_PATH_PHASE_ACCURACY_MSK      GENMASK(7, 4)
#define ADRF6780_I_PATH_PHASE_ACCURACY_MSK      GENMASK(3, 0)

/* ADRF6780_REG_ADC_CONTROL Map */
#define ADRF6780_VDET_OUTPUT_SELECT_MSK         BIT(3)
#define ADRF6780_ADC_START_MSK                  BIT(2)
#define ADRF6780_ADC_EN_MSK                     BIT(1)
#define ADRF6780_ADC_CLOCK_EN_MSK               BIT(0)

/* ADRF6780_REG_ADC_OUTPUT Map */
#define ADRF6780_ADC_STATUS_MSK                 BIT(8)
#define ADRF6780_ADC_VALUE_MSK                  GENMASK(7, 0)

struct adrf6780_state {
        struct spi_device       *spi;
        struct clk              *clkin;
        /* Protect against concurrent accesses to the device */
        struct mutex            lock;
        bool                    vga_buff_en;
        bool                    lo_buff_en;
        bool                    if_mode_en;
        bool                    iq_mode_en;
        bool                    lo_x2_en;
        bool                    lo_ppf_en;
        bool                    lo_en;
        bool                    uc_bias_en;
        bool                    lo_sideband;
        bool                    vdet_out_en;
        u8                      data[3] __aligned(IIO_DMA_MINALIGN);
};

static int __adrf6780_spi_read(struct adrf6780_state *st, unsigned int reg,
                               unsigned int *val)
{
        int ret;
        struct spi_transfer t = {0};

        st->data[0] = 0x80 | (reg << 1);
        st->data[1] = 0x0;
        st->data[2] = 0x0;

        t.rx_buf = &st->data[0];
        t.tx_buf = &st->data[0];
        t.len = 3;

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

        *val = (get_unaligned_be24(&st->data[0]) >> 1) & GENMASK(15, 0);

        return ret;
}

static int adrf6780_spi_read(struct adrf6780_state *st, unsigned int reg,
                             unsigned int *val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __adrf6780_spi_read(st, reg, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int __adrf6780_spi_write(struct adrf6780_state *st,
                                unsigned int reg,
                                unsigned int val)
{
        put_unaligned_be24((val << 1) | (reg << 17), &st->data[0]);

        return spi_write(st->spi, &st->data[0], 3);
}

static int adrf6780_spi_write(struct adrf6780_state *st, unsigned int reg,
                              unsigned int val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __adrf6780_spi_write(st, reg, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int __adrf6780_spi_update_bits(struct adrf6780_state *st,
                                      unsigned int reg, unsigned int mask,
                                      unsigned int val)
{
        int ret;
        unsigned int data, temp;

        ret = __adrf6780_spi_read(st, reg, &data);
        if (ret)
                return ret;

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

        return __adrf6780_spi_write(st, reg, temp);
}

static int adrf6780_spi_update_bits(struct adrf6780_state *st, unsigned int reg,
                                    unsigned int mask, unsigned int val)
{
        int ret;

        mutex_lock(&st->lock);
        ret = __adrf6780_spi_update_bits(st, reg, mask, val);
        mutex_unlock(&st->lock);

        return ret;
}

static int adrf6780_read_adc_raw(struct adrf6780_state *st, unsigned int *read_val)
{
        int ret;

        mutex_lock(&st->lock);

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_ADC_CONTROL,
                                         ADRF6780_ADC_EN_MSK |
                                         ADRF6780_ADC_CLOCK_EN_MSK |
                                         ADRF6780_ADC_START_MSK,
                                         FIELD_PREP(ADRF6780_ADC_EN_MSK, 1) |
                                         FIELD_PREP(ADRF6780_ADC_CLOCK_EN_MSK, 1) |
                                         FIELD_PREP(ADRF6780_ADC_START_MSK, 1));
        if (ret)
                goto exit;

        /*
         * Per ADRF6780 datasheet (Rev. D, page 23, ADC section),
         * wait approximately 200 us for the ADC to be ready.
         */
        fsleep(200);

        ret = __adrf6780_spi_read(st, ADRF6780_REG_ADC_OUTPUT, read_val);
        if (ret)
                goto exit;

        if (!(*read_val & ADRF6780_ADC_STATUS_MSK)) {
                ret = -EINVAL;
                goto exit;
        }

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_ADC_CONTROL,
                                         ADRF6780_ADC_START_MSK,
                                         FIELD_PREP(ADRF6780_ADC_START_MSK, 0));
        if (ret)
                goto exit;

        ret = __adrf6780_spi_read(st, ADRF6780_REG_ADC_OUTPUT, read_val);

exit:
        mutex_unlock(&st->lock);
        return ret;
}

static int adrf6780_read_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             int *val, int *val2, long info)
{
        struct adrf6780_state *dev = iio_priv(indio_dev);
        unsigned int data;
        int ret;

        switch (info) {
        case IIO_CHAN_INFO_RAW:
                ret = adrf6780_read_adc_raw(dev, &data);
                if (ret)
                        return ret;

                *val = data & ADRF6780_ADC_VALUE_MSK;

                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE:
                ret = adrf6780_spi_read(dev, ADRF6780_REG_LINEARIZE, &data);
                if (ret)
                        return ret;

                *val = data & ADRF6780_RDAC_LINEARIZE_MSK;

                return IIO_VAL_INT;
        case IIO_CHAN_INFO_PHASE:
                ret = adrf6780_spi_read(dev, ADRF6780_REG_LO_PATH, &data);
                if (ret)
                        return ret;

                switch (chan->channel2) {
                case IIO_MOD_I:
                        *val = data & ADRF6780_I_PATH_PHASE_ACCURACY_MSK;

                        return IIO_VAL_INT;
                case IIO_MOD_Q:
                        *val = FIELD_GET(ADRF6780_Q_PATH_PHASE_ACCURACY_MSK,
                                         data);

                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

static int adrf6780_write_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int val, int val2, long info)
{
        struct adrf6780_state *st = iio_priv(indio_dev);

        switch (info) {
        case IIO_CHAN_INFO_SCALE:
                return adrf6780_spi_write(st, ADRF6780_REG_LINEARIZE, val);
        case IIO_CHAN_INFO_PHASE:
                switch (chan->channel2) {
                case IIO_MOD_I:
                        return adrf6780_spi_update_bits(st,
                                ADRF6780_REG_LO_PATH,
                                ADRF6780_I_PATH_PHASE_ACCURACY_MSK,
                                FIELD_PREP(ADRF6780_I_PATH_PHASE_ACCURACY_MSK, val));
                case IIO_MOD_Q:
                        return adrf6780_spi_update_bits(st,
                                ADRF6780_REG_LO_PATH,
                                ADRF6780_Q_PATH_PHASE_ACCURACY_MSK,
                                FIELD_PREP(ADRF6780_Q_PATH_PHASE_ACCURACY_MSK, val));
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

static int adrf6780_reg_access(struct iio_dev *indio_dev,
                               unsigned int reg,
                               unsigned int write_val,
                               unsigned int *read_val)
{
        struct adrf6780_state *st = iio_priv(indio_dev);

        if (read_val)
                return adrf6780_spi_read(st, reg, read_val);
        else
                return adrf6780_spi_write(st, reg, write_val);
}

static const struct iio_info adrf6780_info = {
        .read_raw = adrf6780_read_raw,
        .write_raw = adrf6780_write_raw,
        .debugfs_reg_access = &adrf6780_reg_access,
};

#define ADRF6780_CHAN_ADC(_channel) {                   \
        .type = IIO_ALTVOLTAGE,                         \
        .output = 0,                                    \
        .indexed = 1,                                   \
        .channel = _channel,                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)    \
}

#define ADRF6780_CHAN_RDAC(_channel) {                  \
        .type = IIO_ALTVOLTAGE,                         \
        .output = 1,                                    \
        .indexed = 1,                                   \
        .channel = _channel,                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE)  \
}

#define ADRF6780_CHAN_IQ_PHASE(_channel, rf_comp) {             \
        .type = IIO_ALTVOLTAGE,                                 \
        .modified = 1,                                          \
        .output = 1,                                            \
        .indexed = 1,                                           \
        .channel2 = IIO_MOD_##rf_comp,                          \
        .channel = _channel,                                    \
        .info_mask_separate = BIT(IIO_CHAN_INFO_PHASE)          \
}

static const struct iio_chan_spec adrf6780_channels[] = {
        ADRF6780_CHAN_ADC(0),
        ADRF6780_CHAN_RDAC(0),
        ADRF6780_CHAN_IQ_PHASE(0, I),
        ADRF6780_CHAN_IQ_PHASE(0, Q),
};

static int adrf6780_reset(struct adrf6780_state *st)
{
        int ret;
        struct device *dev = &st->spi->dev;

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_CONTROL,
                                         ADRF6780_SOFT_RESET_MSK,
                                         FIELD_PREP(ADRF6780_SOFT_RESET_MSK, 1));
        if (ret)
                return dev_err_probe(dev, ret,
                                     "ADRF6780 SPI software reset failed.\n");

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_CONTROL,
                                         ADRF6780_SOFT_RESET_MSK,
                                         FIELD_PREP(ADRF6780_SOFT_RESET_MSK, 0));
        if (ret)
                return dev_err_probe(dev, ret,
                                     "ADRF6780 SPI software reset disable failed.\n");

        return 0;
}

static int adrf6780_init(struct adrf6780_state *st)
{
        int ret;
        unsigned int chip_id, enable_reg, enable_reg_msk;
        struct device *dev = &st->spi->dev;

        /* Perform a software reset */
        ret = adrf6780_reset(st);
        if (ret)
                return ret;

        ret = __adrf6780_spi_read(st, ADRF6780_REG_CONTROL, &chip_id);
        if (ret)
                return ret;

        chip_id = FIELD_GET(ADRF6780_CHIP_ID_MSK, chip_id);
        if (chip_id != ADRF6780_CHIP_ID)
                return dev_err_probe(dev, -EINVAL,
                                     "ADRF6780 Invalid Chip ID.\n");

        enable_reg_msk = ADRF6780_VGA_BUFFER_EN_MSK |
                        ADRF6780_DETECTOR_EN_MSK |
                        ADRF6780_LO_BUFFER_EN_MSK |
                        ADRF6780_IF_MODE_EN_MSK |
                        ADRF6780_IQ_MODE_EN_MSK |
                        ADRF6780_LO_X2_EN_MSK |
                        ADRF6780_LO_PPF_EN_MSK |
                        ADRF6780_LO_EN_MSK |
                        ADRF6780_UC_BIAS_EN_MSK;

        enable_reg = FIELD_PREP(ADRF6780_VGA_BUFFER_EN_MSK, st->vga_buff_en) |
                        FIELD_PREP(ADRF6780_DETECTOR_EN_MSK, 1) |
                        FIELD_PREP(ADRF6780_LO_BUFFER_EN_MSK, st->lo_buff_en) |
                        FIELD_PREP(ADRF6780_IF_MODE_EN_MSK, st->if_mode_en) |
                        FIELD_PREP(ADRF6780_IQ_MODE_EN_MSK, st->iq_mode_en) |
                        FIELD_PREP(ADRF6780_LO_X2_EN_MSK, st->lo_x2_en) |
                        FIELD_PREP(ADRF6780_LO_PPF_EN_MSK, st->lo_ppf_en) |
                        FIELD_PREP(ADRF6780_LO_EN_MSK, st->lo_en) |
                        FIELD_PREP(ADRF6780_UC_BIAS_EN_MSK, st->uc_bias_en);

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_ENABLE,
                                         enable_reg_msk, enable_reg);
        if (ret)
                return ret;

        ret = __adrf6780_spi_update_bits(st, ADRF6780_REG_LO_PATH,
                                         ADRF6780_LO_SIDEBAND_MSK,
                                         FIELD_PREP(ADRF6780_LO_SIDEBAND_MSK, st->lo_sideband));
        if (ret)
                return ret;

        return __adrf6780_spi_update_bits(st, ADRF6780_REG_ADC_CONTROL,
                ADRF6780_VDET_OUTPUT_SELECT_MSK,
                FIELD_PREP(ADRF6780_VDET_OUTPUT_SELECT_MSK, st->vdet_out_en));
}

static void adrf6780_properties_parse(struct adrf6780_state *st)
{
        struct device *dev = &st->spi->dev;

        st->vga_buff_en = device_property_read_bool(dev, "adi,vga-buff-en");
        st->lo_buff_en = device_property_read_bool(dev, "adi,lo-buff-en");
        st->if_mode_en = device_property_read_bool(dev, "adi,if-mode-en");
        st->iq_mode_en = device_property_read_bool(dev, "adi,iq-mode-en");
        st->lo_x2_en = device_property_read_bool(dev, "adi,lo-x2-en");
        st->lo_ppf_en = device_property_read_bool(dev, "adi,lo-ppf-en");
        st->lo_en = device_property_read_bool(dev, "adi,lo-en");
        st->uc_bias_en = device_property_read_bool(dev, "adi,uc-bias-en");
        st->lo_sideband = device_property_read_bool(dev, "adi,lo-sideband");
        st->vdet_out_en = device_property_read_bool(dev, "adi,vdet-out-en");
}

static void adrf6780_powerdown(void *data)
{
        /* Disable all components in the Enable Register */
        adrf6780_spi_write(data, ADRF6780_REG_ENABLE, 0x0);
}

static int adrf6780_probe(struct spi_device *spi)
{
        struct iio_dev *indio_dev;
        struct adrf6780_state *st;
        struct device *dev = &spi->dev;
        int ret;

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

        st = iio_priv(indio_dev);

        indio_dev->info = &adrf6780_info;
        indio_dev->name = "adrf6780";
        indio_dev->channels = adrf6780_channels;
        indio_dev->num_channels = ARRAY_SIZE(adrf6780_channels);

        st->spi = spi;

        adrf6780_properties_parse(st);

        st->clkin = devm_clk_get_enabled(dev, "lo_in");
        if (IS_ERR(st->clkin))
                return dev_err_probe(dev, PTR_ERR(st->clkin),
                                     "failed to get the LO input clock\n");

        mutex_init(&st->lock);

        ret = adrf6780_init(st);
        if (ret)
                return ret;

        ret = devm_add_action_or_reset(dev, adrf6780_powerdown, st);
        if (ret)
                return ret;

        return devm_iio_device_register(dev, indio_dev);
}

static const struct spi_device_id adrf6780_id[] = {
        { "adrf6780", 0 },
        { }
};
MODULE_DEVICE_TABLE(spi, adrf6780_id);

static const struct of_device_id adrf6780_of_match[] = {
        { .compatible = "adi,adrf6780" },
        { }
};
MODULE_DEVICE_TABLE(of, adrf6780_of_match);

static struct spi_driver adrf6780_driver = {
        .driver = {
                .name = "adrf6780",
                .of_match_table = adrf6780_of_match,
        },
        .probe = adrf6780_probe,
        .id_table = adrf6780_id,
};
module_spi_driver(adrf6780_driver);

MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
MODULE_DESCRIPTION("Analog Devices ADRF6780");
MODULE_LICENSE("GPL v2");