root/drivers/iio/frequency/adf4350.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ADF4350/ADF4351 SPI Wideband Synthesizer driver
 *
 * Copyright 2012-2013 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/gcd.h>
#include <linux/gpio/consumer.h>
#include <asm/div64.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/frequency/adf4350.h>

enum {
        ADF4350_FREQ,
        ADF4350_FREQ_REFIN,
        ADF4350_FREQ_RESOLUTION,
        ADF4350_PWRDOWN,
};

struct adf4350_state {
        struct spi_device               *spi;
        struct gpio_desc                *lock_detect_gpiod;
        struct adf4350_platform_data    *pdata;
        struct clk                      *clk;
        struct clk                      *clkout;
        const char                      *clk_out_name;
        struct clk_hw                   hw;
        unsigned long                   clkin;
        unsigned long                   chspc; /* Channel Spacing */
        unsigned long                   fpfd; /* Phase Frequency Detector */
        unsigned long                   min_out_freq;
        unsigned                        r0_fract;
        unsigned                        r0_int;
        unsigned                        r1_mod;
        unsigned                        r4_rf_div_sel;
        unsigned long                   regs[6];
        unsigned long                   regs_hw[6];
        unsigned long long              freq_req;
        /*
         * Lock to protect the state of the device from potential concurrent
         * writes. The device is configured via a sequence of SPI writes,
         * and this lock is meant to prevent the start of another sequence
         * before another one has finished.
         */
        struct mutex                    lock;
        /*
         * DMA (thus cache coherency maintenance) may require that
         * transfer buffers live in their own cache lines.
         */
        __be32                          val __aligned(IIO_DMA_MINALIGN);
};

#define to_adf4350_state(_hw) container_of(_hw, struct adf4350_state, hw)

static struct adf4350_platform_data default_pdata = {
        .channel_spacing = 10000,
        .r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
                            ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500),
        .r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
        .r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
                            ADF4350_REG4_MUTE_TILL_LOCK_EN,
};

static int adf4350_sync_config(struct adf4350_state *st)
{
        int ret, i, doublebuf = 0;

        for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) {
                if ((st->regs_hw[i] != st->regs[i]) ||
                        ((i == ADF4350_REG0) && doublebuf)) {
                        switch (i) {
                        case ADF4350_REG1:
                        case ADF4350_REG4:
                                doublebuf = 1;
                                break;
                        }

                        st->val  = cpu_to_be32(st->regs[i] | i);
                        ret = spi_write(st->spi, &st->val, 4);
                        if (ret < 0)
                                return ret;
                        st->regs_hw[i] = st->regs[i];
                        dev_dbg(&st->spi->dev, "[%d] 0x%X\n",
                                i, (u32)st->regs[i] | i);
                }
        }
        return 0;
}

static int adf4350_reg_access(struct iio_dev *indio_dev,
                              unsigned reg, unsigned writeval,
                              unsigned *readval)
{
        struct adf4350_state *st = iio_priv(indio_dev);
        int ret;

        if (reg > ADF4350_REG5)
                return -EINVAL;

        mutex_lock(&st->lock);
        if (readval == NULL) {
                st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2));
                ret = adf4350_sync_config(st);
        } else {
                *readval =  st->regs_hw[reg];
                ret = 0;
        }
        mutex_unlock(&st->lock);

        return ret;
}

static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt)
{
        struct adf4350_platform_data *pdata = st->pdata;

        do {
                r_cnt++;
                st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) /
                           (r_cnt * (pdata->ref_div2_en ? 2 : 1));
        } while (st->fpfd > ADF4350_MAX_FREQ_PFD);

        return r_cnt;
}

static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
{
        struct adf4350_platform_data *pdata = st->pdata;
        u64 tmp;
        u32 div_gcd, prescaler, chspc;
        u16 mdiv, r_cnt = 0;
        u8 band_sel_div;

        if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq)
                return -EINVAL;

        st->r4_rf_div_sel = 0;

        /*
         * !\TODO: The below computation is making sure we get a power of 2
         * shift (st->r4_rf_div_sel) so that freq becomes higher or equal to
         * ADF4350_MIN_VCO_FREQ. This might be simplified with fls()/fls_long()
         * and friends.
         */
        while (freq < ADF4350_MIN_VCO_FREQ) {
                freq <<= 1;
                st->r4_rf_div_sel++;
        }

        if (freq > ADF4350_MAX_FREQ_45_PRESC) {
                prescaler = ADF4350_REG1_PRESCALER;
                mdiv = 75;
        } else {
                prescaler = 0;
                mdiv = 23;
        }

        /*
         * Allow a predefined reference division factor
         * if not set, compute our own
         */
        if (pdata->ref_div_factor)
                r_cnt = pdata->ref_div_factor - 1;

        chspc = st->chspc;

        do  {
                do {
                        do {
                                r_cnt = adf4350_tune_r_cnt(st, r_cnt);
                                st->r1_mod = st->fpfd / chspc;
                                if (r_cnt > ADF4350_MAX_R_CNT) {
                                        /* try higher spacing values */
                                        chspc++;
                                        r_cnt = 0;
                                }
                        } while ((st->r1_mod > ADF4350_MAX_MODULUS) && r_cnt);
                } while (r_cnt == 0);

                tmp = freq * (u64)st->r1_mod + (st->fpfd >> 1);
                do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
                st->r0_fract = do_div(tmp, st->r1_mod);
                st->r0_int = tmp;
        } while (mdiv > st->r0_int);

        band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);

        if (st->r0_fract && st->r1_mod) {
                div_gcd = gcd(st->r1_mod, st->r0_fract);
                st->r1_mod /= div_gcd;
                st->r0_fract /= div_gcd;
        } else {
                st->r0_fract = 0;
                st->r1_mod = 1;
        }

        dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
                "REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
                "R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
                freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
                1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
                band_sel_div);

        st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
                                 ADF4350_REG0_FRACT(st->r0_fract);

        st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(1) |
                                 ADF4350_REG1_MOD(st->r1_mod) |
                                 prescaler;

        st->regs[ADF4350_REG2] =
                ADF4350_REG2_10BIT_R_CNT(r_cnt) |
                ADF4350_REG2_DOUBLE_BUFF_EN |
                (pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
                (pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
                (pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
                ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
                ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
                ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x3)));

        st->regs[ADF4350_REG3] = pdata->r3_user_settings &
                                 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
                                 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
                                 ADF4350_REG3_12BIT_CSR_EN |
                                 ADF4351_REG3_CHARGE_CANCELLATION_EN |
                                 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
                                 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);

        st->regs[ADF4350_REG4] =
                ADF4350_REG4_FEEDBACK_FUND |
                ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
                ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
                ADF4350_REG4_RF_OUT_EN |
                (pdata->r4_user_settings &
                (ADF4350_REG4_OUTPUT_PWR(0x3) |
                ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
                ADF4350_REG4_AUX_OUTPUT_EN |
                ADF4350_REG4_AUX_OUTPUT_FUND |
                ADF4350_REG4_MUTE_TILL_LOCK_EN));

        st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
        st->freq_req = freq;

        return adf4350_sync_config(st);
}

static ssize_t adf4350_write(struct iio_dev *indio_dev,
                                    uintptr_t private,
                                    const struct iio_chan_spec *chan,
                                    const char *buf, size_t len)
{
        struct adf4350_state *st = iio_priv(indio_dev);
        unsigned long long readin;
        unsigned long tmp;
        int ret;

        ret = kstrtoull(buf, 10, &readin);
        if (ret)
                return ret;

        mutex_lock(&st->lock);
        switch ((u32)private) {
        case ADF4350_FREQ:
                ret = adf4350_set_freq(st, readin);
                break;
        case ADF4350_FREQ_REFIN:
                if (readin > ADF4350_MAX_FREQ_REFIN) {
                        ret = -EINVAL;
                        break;
                }

                if (st->clk) {
                        tmp = clk_round_rate(st->clk, readin);
                        if (tmp != readin) {
                                ret = -EINVAL;
                                break;
                        }
                        ret = clk_set_rate(st->clk, tmp);
                        if (ret < 0)
                                break;
                }
                st->clkin = readin;
                ret = adf4350_set_freq(st, st->freq_req);
                break;
        case ADF4350_FREQ_RESOLUTION:
                if (readin == 0)
                        ret = -EINVAL;
                else
                        st->chspc = readin;
                break;
        case ADF4350_PWRDOWN:
                if (readin)
                        st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
                else
                        st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;

                adf4350_sync_config(st);
                break;
        default:
                ret = -EINVAL;
        }
        mutex_unlock(&st->lock);

        return ret ? ret : len;
}

static ssize_t adf4350_read(struct iio_dev *indio_dev,
                                   uintptr_t private,
                                   const struct iio_chan_spec *chan,
                                   char *buf)
{
        struct adf4350_state *st = iio_priv(indio_dev);
        unsigned long long val;
        int ret = 0;

        mutex_lock(&st->lock);
        switch ((u32)private) {
        case ADF4350_FREQ:
                val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
                        (u64)st->fpfd;
                do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
                /* PLL unlocked? return error */
                if (st->lock_detect_gpiod)
                        if (!gpiod_get_value(st->lock_detect_gpiod)) {
                                dev_dbg(&st->spi->dev, "PLL un-locked\n");
                                ret = -EBUSY;
                        }
                break;
        case ADF4350_FREQ_REFIN:
                if (st->clk)
                        st->clkin = clk_get_rate(st->clk);

                val = st->clkin;
                break;
        case ADF4350_FREQ_RESOLUTION:
                val = st->chspc;
                break;
        case ADF4350_PWRDOWN:
                val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
                break;
        default:
                ret = -EINVAL;
                val = 0;
        }
        mutex_unlock(&st->lock);

        return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
}

#define _ADF4350_EXT_INFO(_name, _ident) { \
        .name = _name, \
        .read = adf4350_read, \
        .write = adf4350_write, \
        .private = _ident, \
        .shared = IIO_SEPARATE, \
}

static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
        /* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
         * values > 2^32 in order to support the entire frequency range
         * in Hz. Using scale is a bit ugly.
         */
        _ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
        _ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
        _ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
        _ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
        { }
};

static const struct iio_chan_spec adf4350_chan = {
        .type = IIO_ALTVOLTAGE,
        .indexed = 1,
        .output = 1,
        .ext_info = adf4350_ext_info,
};

static const struct iio_info adf4350_info = {
        .debugfs_reg_access = &adf4350_reg_access,
};

static void adf4350_clk_del_provider(void *data)
{
        struct adf4350_state *st = data;

        of_clk_del_provider(st->spi->dev.of_node);
}

static unsigned long adf4350_clk_recalc_rate(struct clk_hw *hw,
                                             unsigned long parent_rate)
{
        struct adf4350_state *st = to_adf4350_state(hw);
        unsigned long long tmp;

        tmp = (u64)(st->r0_int * st->r1_mod + st->r0_fract) * st->fpfd;
        do_div(tmp, st->r1_mod * (1 << st->r4_rf_div_sel));

        return tmp;
}

static int adf4350_clk_set_rate(struct clk_hw *hw,
                                unsigned long rate,
                                unsigned long parent_rate)
{
        struct adf4350_state *st = to_adf4350_state(hw);

        if (parent_rate == 0 || parent_rate > ADF4350_MAX_FREQ_REFIN)
                return -EINVAL;

        st->clkin = parent_rate;

        return adf4350_set_freq(st, rate);
}

static int adf4350_clk_prepare(struct clk_hw *hw)
{
        struct adf4350_state *st = to_adf4350_state(hw);

        st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;

        return adf4350_sync_config(st);
}

static void adf4350_clk_unprepare(struct clk_hw *hw)
{
        struct adf4350_state *st = to_adf4350_state(hw);

        st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;

        adf4350_sync_config(st);
}

static int adf4350_clk_is_enabled(struct clk_hw *hw)
{
        struct adf4350_state *st = to_adf4350_state(hw);

        return (st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
}

static const struct clk_ops adf4350_clk_ops = {
        .recalc_rate = adf4350_clk_recalc_rate,
        .set_rate = adf4350_clk_set_rate,
        .prepare = adf4350_clk_prepare,
        .unprepare = adf4350_clk_unprepare,
        .is_enabled = adf4350_clk_is_enabled,
};

static int adf4350_clk_register(struct adf4350_state *st)
{
        struct spi_device *spi = st->spi;
        struct clk_init_data init;
        struct clk *clk;
        const char *parent_name;
        int ret;

        if (!device_property_present(&spi->dev, "#clock-cells"))
                return 0;

        if (device_property_read_string(&spi->dev, "clock-output-names", &init.name)) {
                init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
                                           fwnode_get_name(dev_fwnode(&spi->dev)));
                if (!init.name)
                        return -ENOMEM;
        }

        parent_name = of_clk_get_parent_name(spi->dev.of_node, 0);
        if (!parent_name)
                return -EINVAL;

        init.ops = &adf4350_clk_ops;
        init.parent_names = &parent_name;
        init.num_parents = 1;
        init.flags = CLK_SET_RATE_PARENT;

        st->hw.init = &init;
        clk = devm_clk_register(&spi->dev, &st->hw);
        if (IS_ERR(clk))
                return PTR_ERR(clk);

        ret = of_clk_add_provider(spi->dev.of_node, of_clk_src_simple_get, clk);
        if (ret)
                return ret;

        st->clkout = clk;

        return devm_add_action_or_reset(&spi->dev, adf4350_clk_del_provider, st);
}

static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
{
        struct adf4350_platform_data *pdata;
        unsigned int tmp;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return NULL;

        snprintf(pdata->name, sizeof(pdata->name), "%pfw", dev_fwnode(dev));

        tmp = 10000;
        device_property_read_u32(dev, "adi,channel-spacing", &tmp);
        pdata->channel_spacing = tmp;

        tmp = 0;
        device_property_read_u32(dev, "adi,power-up-frequency", &tmp);
        pdata->power_up_frequency = tmp;

        tmp = 0;
        device_property_read_u32(dev, "adi,reference-div-factor", &tmp);
        pdata->ref_div_factor = tmp;

        pdata->ref_doubler_en = device_property_read_bool(dev, "adi,reference-doubler-enable");
        pdata->ref_div2_en = device_property_read_bool(dev, "adi,reference-div2-enable");

        /* r2_user_settings */
        pdata->r2_user_settings = 0;
        if (device_property_read_bool(dev, "adi,phase-detector-polarity-positive-enable"))
                pdata->r2_user_settings |= ADF4350_REG2_PD_POLARITY_POS;
        if (device_property_read_bool(dev, "adi,lock-detect-precision-6ns-enable"))
                pdata->r2_user_settings |= ADF4350_REG2_LDP_6ns;
        if (device_property_read_bool(dev, "adi,lock-detect-function-integer-n-enable"))
                pdata->r2_user_settings |= ADF4350_REG2_LDF_INT_N;

        tmp = 2500;
        device_property_read_u32(dev, "adi,charge-pump-current", &tmp);
        pdata->r2_user_settings |= ADF4350_REG2_CHARGE_PUMP_CURR_uA(tmp);

        tmp = 0;
        device_property_read_u32(dev, "adi,muxout-select", &tmp);
        pdata->r2_user_settings |= ADF4350_REG2_MUXOUT(tmp);

        if (device_property_read_bool(dev, "adi,low-spur-mode-enable"))
                pdata->r2_user_settings |= ADF4350_REG2_NOISE_MODE(0x3);

        /* r3_user_settings */

        pdata->r3_user_settings = 0;
        if (device_property_read_bool(dev, "adi,cycle-slip-reduction-enable"))
                pdata->r3_user_settings |= ADF4350_REG3_12BIT_CSR_EN;
        if (device_property_read_bool(dev, "adi,charge-cancellation-enable"))
                pdata->r3_user_settings |= ADF4351_REG3_CHARGE_CANCELLATION_EN;
        if (device_property_read_bool(dev, "adi,anti-backlash-3ns-enable"))
                pdata->r3_user_settings |= ADF4351_REG3_ANTI_BACKLASH_3ns_EN;
        if (device_property_read_bool(dev, "adi,band-select-clock-mode-high-enable"))
                pdata->r3_user_settings |= ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH;

        tmp = 0;
        device_property_read_u32(dev, "adi,12bit-clk-divider", &tmp);
        pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV(tmp);

        tmp = 0;
        device_property_read_u32(dev, "adi,clk-divider-mode", &tmp);
        pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV_MODE(tmp);

        /* r4_user_settings */

        pdata->r4_user_settings = 0;
        if (device_property_read_bool(dev, "adi,aux-output-enable"))
                pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_EN;
        if (device_property_read_bool(dev, "adi,aux-output-fundamental-enable"))
                pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_FUND;
        if (device_property_read_bool(dev, "adi,mute-till-lock-enable"))
                pdata->r4_user_settings |= ADF4350_REG4_MUTE_TILL_LOCK_EN;

        tmp = 0;
        device_property_read_u32(dev, "adi,output-power", &tmp);
        pdata->r4_user_settings |= ADF4350_REG4_OUTPUT_PWR(tmp);

        tmp = 0;
        device_property_read_u32(dev, "adi,aux-output-power", &tmp);
        pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_PWR(tmp);

        return pdata;
}

static void adf4350_power_down(void *data)
{
        struct iio_dev *indio_dev = data;
        struct adf4350_state *st = iio_priv(indio_dev);

        st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
        adf4350_sync_config(st);
}

static int adf4350_probe(struct spi_device *spi)
{
        struct adf4350_platform_data *pdata;
        struct iio_dev *indio_dev;
        struct adf4350_state *st;
        struct clk *clk = NULL;
        int ret;

        if (dev_fwnode(&spi->dev)) {
                pdata = adf4350_parse_dt(&spi->dev);
                if (pdata == NULL)
                        return -EINVAL;
        } else {
                pdata = dev_get_platdata(&spi->dev);
        }

        if (!pdata) {
                dev_warn(&spi->dev, "no platform data? using default\n");
                pdata = &default_pdata;
        }

        if (!pdata->clkin) {
                clk = devm_clk_get_enabled(&spi->dev, "clkin");
                if (IS_ERR(clk))
                        return PTR_ERR(clk);
        }

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

        st = iio_priv(indio_dev);

        ret = devm_regulator_get_enable(&spi->dev, "vcc");
        if (ret)
                return ret;

        st->spi = spi;
        st->pdata = pdata;

        indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
                spi_get_device_id(spi)->name;

        indio_dev->info = &adf4350_info;
        indio_dev->modes = INDIO_DIRECT_MODE;

        mutex_init(&st->lock);

        st->chspc = pdata->channel_spacing;
        if (clk) {
                st->clk = clk;
                st->clkin = clk_get_rate(clk);
        } else {
                st->clkin = pdata->clkin;
        }

        st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
                ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;

        memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));

        st->lock_detect_gpiod = devm_gpiod_get_optional(&spi->dev, NULL,
                                                        GPIOD_IN);
        if (IS_ERR(st->lock_detect_gpiod))
                return PTR_ERR(st->lock_detect_gpiod);

        if (pdata->power_up_frequency) {
                ret = adf4350_set_freq(st, pdata->power_up_frequency);
                if (ret)
                        return ret;
        }

        ret = adf4350_clk_register(st);
        if (ret)
                return ret;

        if (!st->clkout) {
                indio_dev->channels = &adf4350_chan;
                indio_dev->num_channels = 1;
        }

        ret = devm_add_action_or_reset(&spi->dev, adf4350_power_down, indio_dev);
        if (ret)
                return ret;

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

static const struct of_device_id adf4350_of_match[] = {
        { .compatible = "adi,adf4350", },
        { .compatible = "adi,adf4351", },
        { }
};
MODULE_DEVICE_TABLE(of, adf4350_of_match);

static const struct spi_device_id adf4350_id[] = {
        {"adf4350", 4350},
        {"adf4351", 4351},
        { }
};
MODULE_DEVICE_TABLE(spi, adf4350_id);

static struct spi_driver adf4350_driver = {
        .driver = {
                .name   = "adf4350",
                .of_match_table = adf4350_of_match,
        },
        .probe          = adf4350_probe,
        .id_table       = adf4350_id,
};
module_spi_driver(adf4350_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
MODULE_LICENSE("GPL v2");