// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD5592R Digital <-> Analog converters driver
 *
 * Copyright 2015-2016 Analog Devices Inc.
 * Author: Paul Cercueil <paul.cercueil@analog.com>
 */

#include "ad5592r-base.h"

#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>

#define AD5592R_GPIO_READBACK_EN        BIT(10)
#define AD5592R_LDAC_READBACK_EN        BIT(6)

static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
{
        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
        struct spi_transfer t = {
                        .tx_buf = &st->spi_msg_nop,
                        .rx_buf = buf,
                        .len = 2
                };

        st->spi_msg_nop = 0; /* NOP */

        return spi_sync_transfer(spi, &t, 1);
}

static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
{
        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);

        st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);

        return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
}

static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
{
        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
        int ret;

        st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));

        ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
        if (ret)
                return ret;

        /*
         * Invalid data:
         * See Figure 40. Single-Channel ADC Conversion Sequence
         */
        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
        if (ret)
                return ret;

        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
        if (ret)
                return ret;

        *value = be16_to_cpu(st->spi_msg);

        return 0;
}

static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
{
        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);

        st->spi_msg = cpu_to_be16((reg << 11) | value);

        return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
}

static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
{
        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
        int ret;

        st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) |
                                   AD5592R_LDAC_READBACK_EN | (reg << 2));

        ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
        if (ret)
                return ret;

        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
        if (ret)
                return ret;

        *value = be16_to_cpu(st->spi_msg);

        return 0;
}

static int ad5592r_gpio_read(struct ad5592r_state *st, u8 *value)
{
        int ret;

        ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN,
                                AD5592R_GPIO_READBACK_EN | st->gpio_in);
        if (ret)
                return ret;

        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
        if (ret)
                return ret;

        *value = (u8) be16_to_cpu(st->spi_msg);

        return 0;
}

static const struct ad5592r_rw_ops ad5592r_rw_ops = {
        .write_dac = ad5592r_write_dac,
        .read_adc = ad5592r_read_adc,
        .reg_write = ad5592r_reg_write,
        .reg_read = ad5592r_reg_read,
        .gpio_read = ad5592r_gpio_read,
};

static int ad5592r_spi_probe(struct spi_device *spi)
{
        const struct spi_device_id *id = spi_get_device_id(spi);

        return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
}

static void ad5592r_spi_remove(struct spi_device *spi)
{
        ad5592r_remove(&spi->dev);
}

static const struct spi_device_id ad5592r_spi_ids[] = {
        { .name = "ad5592r", },
        { }
};
MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);

static const struct of_device_id ad5592r_of_match[] = {
        { .compatible = "adi,ad5592r", },
        { }
};
MODULE_DEVICE_TABLE(of, ad5592r_of_match);

static const struct acpi_device_id ad5592r_acpi_match[] = {
        {"ADS5592", },
        { }
};
MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);

static struct spi_driver ad5592r_spi_driver = {
        .driver = {
                .name = "ad5592r",
                .of_match_table = ad5592r_of_match,
                .acpi_match_table = ad5592r_acpi_match,
        },
        .probe = ad5592r_spi_probe,
        .remove = ad5592r_spi_remove,
        .id_table = ad5592r_spi_ids,
};
module_spi_driver(ad5592r_spi_driver);

MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_AD5592R");