// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale Vybrid vf610 DAC driver
 *
 * Copyright 2016 Toradex AG
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

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

#define VF610_DACx_STATCTRL             0x20

#define VF610_DAC_DACEN                 BIT(15)
#define VF610_DAC_DACRFS                BIT(14)
#define VF610_DAC_LPEN                  BIT(11)

#define VF610_DAC_DAT0(x)               ((x) & 0xFFF)

enum vf610_conversion_mode_sel {
        VF610_DAC_CONV_HIGH_POWER,
        VF610_DAC_CONV_LOW_POWER,
};

struct vf610_dac {
        struct clk *clk;
        struct device *dev;
        enum vf610_conversion_mode_sel conv_mode;
        void __iomem *regs;
        struct mutex lock;
};

static void vf610_dac_init(struct vf610_dac *info)
{
        int val;

        info->conv_mode = VF610_DAC_CONV_LOW_POWER;
        val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
                VF610_DAC_LPEN;
        writel(val, info->regs + VF610_DACx_STATCTRL);
}

static void vf610_dac_exit(struct vf610_dac *info)
{
        int val;

        val = readl(info->regs + VF610_DACx_STATCTRL);
        val &= ~VF610_DAC_DACEN;
        writel(val, info->regs + VF610_DACx_STATCTRL);
}

static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
                                const struct iio_chan_spec *chan,
                                unsigned int mode)
{
        struct vf610_dac *info = iio_priv(indio_dev);
        int val;

        mutex_lock(&info->lock);
        info->conv_mode = mode;
        val = readl(info->regs + VF610_DACx_STATCTRL);
        if (mode)
                val |= VF610_DAC_LPEN;
        else
                val &= ~VF610_DAC_LPEN;
        writel(val, info->regs + VF610_DACx_STATCTRL);
        mutex_unlock(&info->lock);

        return 0;
}

static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
                                const struct iio_chan_spec *chan)
{
        struct vf610_dac *info = iio_priv(indio_dev);

        return info->conv_mode;
}

static const char * const vf610_conv_modes[] = { "high-power", "low-power" };

static const struct iio_enum vf610_conversion_mode = {
        .items = vf610_conv_modes,
        .num_items = ARRAY_SIZE(vf610_conv_modes),
        .get = vf610_get_conversion_mode,
        .set = vf610_set_conversion_mode,
};

static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
        IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
                &vf610_conversion_mode),
        { }
};

#define VF610_DAC_CHAN(_chan_type) { \
        .type = (_chan_type), \
        .output = 1, \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
        .ext_info = vf610_ext_info, \
}

static const struct iio_chan_spec vf610_dac_iio_channels[] = {
        VF610_DAC_CHAN(IIO_VOLTAGE),
};

static int vf610_read_raw(struct iio_dev *indio_dev,
                        struct iio_chan_spec const *chan,
                        int *val, int *val2,
                        long mask)
{
        struct vf610_dac *info = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                *val = VF610_DAC_DAT0(readl(info->regs));
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                /*
                 * DACRFS is always 1 for valid reference and typical
                 * reference voltage as per Vybrid datasheet is 3.3V
                 * from section 9.1.2.1 of Vybrid datasheet
                 */
                *val = 3300 /* mV */;
                *val2 = 12;
                return IIO_VAL_FRACTIONAL_LOG2;

        default:
                return -EINVAL;
        }
}

static int vf610_write_raw(struct iio_dev *indio_dev,
                        struct iio_chan_spec const *chan,
                        int val, int val2,
                        long mask)
{
        struct vf610_dac *info = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                mutex_lock(&info->lock);
                writel(VF610_DAC_DAT0(val), info->regs);
                mutex_unlock(&info->lock);
                return 0;

        default:
                return -EINVAL;
        }
}

static const struct iio_info vf610_dac_iio_info = {
        .read_raw = &vf610_read_raw,
        .write_raw = &vf610_write_raw,
};

static const struct of_device_id vf610_dac_match[] = {
        { .compatible = "fsl,vf610-dac", },
        { }
};
MODULE_DEVICE_TABLE(of, vf610_dac_match);

static int vf610_dac_probe(struct platform_device *pdev)
{
        struct iio_dev *indio_dev;
        struct vf610_dac *info;
        int ret;

        indio_dev = devm_iio_device_alloc(&pdev->dev,
                                        sizeof(struct vf610_dac));
        if (!indio_dev)
                return -ENOMEM;

        info = iio_priv(indio_dev);
        info->dev = &pdev->dev;

        info->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(info->regs))
                return PTR_ERR(info->regs);

        info->clk = devm_clk_get_enabled(&pdev->dev, "dac");
        if (IS_ERR(info->clk))
                return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
                                     "Failed getting clock\n");

        platform_set_drvdata(pdev, indio_dev);

        indio_dev->name = dev_name(&pdev->dev);
        indio_dev->info = &vf610_dac_iio_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = vf610_dac_iio_channels;
        indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);

        mutex_init(&info->lock);

        vf610_dac_init(info);

        ret = iio_device_register(indio_dev);
        if (ret) {
                dev_err(&pdev->dev, "Couldn't register the device\n");
                goto error_iio_device_register;
        }

        return 0;

error_iio_device_register:
        vf610_dac_exit(info);

        return ret;
}

static void vf610_dac_remove(struct platform_device *pdev)
{
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
        struct vf610_dac *info = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);
        vf610_dac_exit(info);
}

static int vf610_dac_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct vf610_dac *info = iio_priv(indio_dev);

        vf610_dac_exit(info);
        clk_disable_unprepare(info->clk);

        return 0;
}

static int vf610_dac_resume(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct vf610_dac *info = iio_priv(indio_dev);
        int ret;

        ret = clk_prepare_enable(info->clk);
        if (ret)
                return ret;

        vf610_dac_init(info);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend,
                                vf610_dac_resume);

static struct platform_driver vf610_dac_driver = {
        .probe          = vf610_dac_probe,
        .remove         = vf610_dac_remove,
        .driver         = {
                .name   = "vf610-dac",
                .of_match_table = vf610_dac_match,
                .pm     = pm_sleep_ptr(&vf610_dac_pm_ops),
        },
};
module_platform_driver(vf610_dac_driver);

MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
MODULE_DESCRIPTION("Freescale VF610 DAC driver");
MODULE_LICENSE("GPL v2");