// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015 Intel Corporation
 *
 * Driver for TXC PA12203001 Proximity and Ambient Light Sensor.
 *
 * To do: Interrupt support.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>

#define PA12203001_DRIVER_NAME  "pa12203001"

#define PA12203001_REG_CFG0             0x00
#define PA12203001_REG_CFG1             0x01
#define PA12203001_REG_CFG2             0x02
#define PA12203001_REG_CFG3             0x03

#define PA12203001_REG_ADL              0x0b
#define PA12203001_REG_PDH              0x0e

#define PA12203001_REG_POFS             0x10
#define PA12203001_REG_PSET             0x11

#define PA12203001_ALS_EN_MASK          BIT(0)
#define PA12203001_PX_EN_MASK           BIT(1)
#define PA12203001_PX_NORMAL_MODE_MASK          GENMASK(7, 6)
#define PA12203001_AFSR_MASK            GENMASK(5, 4)
#define PA12203001_AFSR_SHIFT           4

#define PA12203001_PSCAN                        0x03

/* als range 31000, ps, als disabled */
#define PA12203001_REG_CFG0_DEFAULT             0x30

/* led current: 100 mA */
#define PA12203001_REG_CFG1_DEFAULT             0x20

/* ps mode: normal, interrupts not active */
#define PA12203001_REG_CFG2_DEFAULT             0xcc

#define PA12203001_REG_CFG3_DEFAULT             0x00

#define PA12203001_SLEEP_DELAY_MS               3000

#define PA12203001_CHIP_ENABLE          0xff
#define PA12203001_CHIP_DISABLE         0x00

/* available scales: corresponding to [500, 4000, 7000, 31000]  lux */
static const int pa12203001_scales[] = { 7629, 61036, 106813, 473029};

struct pa12203001_data {
        struct i2c_client *client;

        /* protect device states */
        struct mutex lock;

        bool als_enabled;
        bool px_enabled;
        bool als_needs_enable;
        bool px_needs_enable;

        struct regmap *map;
};

static const struct {
        u8 reg;
        u8 val;
} regvals[] = {
        {PA12203001_REG_CFG0, PA12203001_REG_CFG0_DEFAULT},
        {PA12203001_REG_CFG1, PA12203001_REG_CFG1_DEFAULT},
        {PA12203001_REG_CFG2, PA12203001_REG_CFG2_DEFAULT},
        {PA12203001_REG_CFG3, PA12203001_REG_CFG3_DEFAULT},
        {PA12203001_REG_PSET, PA12203001_PSCAN},
};

static IIO_CONST_ATTR(in_illuminance_scale_available,
                      "0.007629 0.061036 0.106813 0.473029");

static struct attribute *pa12203001_attrs[] = {
        &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
        NULL
};

static const struct attribute_group pa12203001_attr_group = {
        .attrs = pa12203001_attrs,
};

static const struct iio_chan_spec pa12203001_channels[] = {
        {
                .type = IIO_LIGHT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                                      BIT(IIO_CHAN_INFO_SCALE),
        },
        {
                .type = IIO_PROXIMITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
        }
};

static const struct regmap_range pa12203001_volatile_regs_ranges[] = {
        regmap_reg_range(PA12203001_REG_ADL, PA12203001_REG_ADL + 1),
        regmap_reg_range(PA12203001_REG_PDH, PA12203001_REG_PDH),
};

static const struct regmap_access_table pa12203001_volatile_regs = {
        .yes_ranges = pa12203001_volatile_regs_ranges,
        .n_yes_ranges = ARRAY_SIZE(pa12203001_volatile_regs_ranges),
};

static const struct regmap_config pa12203001_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = PA12203001_REG_PSET,
        .cache_type = REGCACHE_RBTREE,
        .volatile_table = &pa12203001_volatile_regs,
};

static inline int pa12203001_als_enable(struct pa12203001_data *data, u8 enable)
{
        int ret;

        ret = regmap_update_bits(data->map, PA12203001_REG_CFG0,
                                 PA12203001_ALS_EN_MASK, enable);
        if (ret < 0)
                return ret;

        data->als_enabled = !!enable;

        return 0;
}

static inline int pa12203001_px_enable(struct pa12203001_data *data, u8 enable)
{
        int ret;

        ret = regmap_update_bits(data->map, PA12203001_REG_CFG0,
                                 PA12203001_PX_EN_MASK, enable);
        if (ret < 0)
                return ret;

        data->px_enabled = !!enable;

        return 0;
}

static int pa12203001_set_power_state(struct pa12203001_data *data, bool on,
                                      u8 mask)
{
#ifdef CONFIG_PM
        int ret;

        if (on && (mask & PA12203001_ALS_EN_MASK)) {
                mutex_lock(&data->lock);
                if (data->px_enabled) {
                        ret = pa12203001_als_enable(data,
                                                    PA12203001_ALS_EN_MASK);
                        if (ret < 0)
                                goto err;
                } else {
                        data->als_needs_enable = true;
                }
                mutex_unlock(&data->lock);
        }

        if (on && (mask & PA12203001_PX_EN_MASK)) {
                mutex_lock(&data->lock);
                if (data->als_enabled) {
                        ret = pa12203001_px_enable(data, PA12203001_PX_EN_MASK);
                        if (ret < 0)
                                goto err;
                } else {
                        data->px_needs_enable = true;
                }
                mutex_unlock(&data->lock);
        }

        if (on)
                return pm_runtime_resume_and_get(&data->client->dev);

        return pm_runtime_put_autosuspend(&data->client->dev);

err:
        mutex_unlock(&data->lock);
        return ret;

#endif
        return 0;
}

static int pa12203001_read_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan, int *val,
                               int *val2, long mask)
{
        struct pa12203001_data *data = iio_priv(indio_dev);
        int ret;
        u8 dev_mask;
        unsigned int reg_byte;
        __le16 reg_word;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_LIGHT:
                        dev_mask = PA12203001_ALS_EN_MASK;
                        ret = pa12203001_set_power_state(data, true, dev_mask);
                        if (ret < 0)
                                return ret;
                        /*
                         * ALS ADC value is stored in registers
                         * PA12203001_REG_ADL and in PA12203001_REG_ADL + 1.
                         */
                        ret = regmap_bulk_read(data->map, PA12203001_REG_ADL,
                                               &reg_word, 2);
                        if (ret < 0)
                                goto reg_err;

                        *val = le16_to_cpu(reg_word);
                        ret = pa12203001_set_power_state(data, false, dev_mask);
                        if (ret < 0)
                                return ret;
                        break;
                case IIO_PROXIMITY:
                        dev_mask = PA12203001_PX_EN_MASK;
                        ret = pa12203001_set_power_state(data, true, dev_mask);
                        if (ret < 0)
                                return ret;
                        ret = regmap_read(data->map, PA12203001_REG_PDH,
                                          &reg_byte);
                        if (ret < 0)
                                goto reg_err;

                        *val = reg_byte;
                        ret = pa12203001_set_power_state(data, false, dev_mask);
                        if (ret < 0)
                                return ret;
                        break;
                default:
                        return -EINVAL;
                }
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                ret = regmap_read(data->map, PA12203001_REG_CFG0, &reg_byte);
                if (ret < 0)
                        return ret;
                *val = 0;
                reg_byte = (reg_byte & PA12203001_AFSR_MASK);
                *val2 = pa12203001_scales[reg_byte >> 4];
                return IIO_VAL_INT_PLUS_MICRO;
        default:
                return -EINVAL;
        }

reg_err:
        pa12203001_set_power_state(data, false, dev_mask);
        return ret;
}

static int pa12203001_write_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan, int val,
                                int val2, long mask)
{
        struct pa12203001_data *data = iio_priv(indio_dev);
        int i, ret, new_val;
        unsigned int reg_byte;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                ret = regmap_read(data->map, PA12203001_REG_CFG0, &reg_byte);
                if (val != 0 || ret < 0)
                        return -EINVAL;
                for (i = 0; i < ARRAY_SIZE(pa12203001_scales); i++) {
                        if (val2 == pa12203001_scales[i]) {
                                new_val = i << PA12203001_AFSR_SHIFT;
                                return regmap_update_bits(data->map,
                                                          PA12203001_REG_CFG0,
                                                          PA12203001_AFSR_MASK,
                                                          new_val);
                        }
                }
                break;
        default:
                break;
        }

        return -EINVAL;
}

static const struct iio_info pa12203001_info = {
        .read_raw = pa12203001_read_raw,
        .write_raw = pa12203001_write_raw,
        .attrs = &pa12203001_attr_group,
};

static int pa12203001_init(struct iio_dev *indio_dev)
{
        struct pa12203001_data *data = iio_priv(indio_dev);
        int i, ret;

        for (i = 0; i < ARRAY_SIZE(regvals); i++) {
                ret = regmap_write(data->map, regvals[i].reg, regvals[i].val);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int pa12203001_power_chip(struct iio_dev *indio_dev, u8 state)
{
        struct pa12203001_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->lock);
        ret = pa12203001_als_enable(data, state);
        if (ret < 0)
                goto out;

        ret = pa12203001_px_enable(data, state);

out:
        mutex_unlock(&data->lock);
        return ret;
}

static int pa12203001_probe(struct i2c_client *client)
{
        struct pa12203001_data *data;
        struct iio_dev *indio_dev;
        int ret;

        indio_dev = devm_iio_device_alloc(&client->dev,
                                          sizeof(struct pa12203001_data));
        if (!indio_dev)
                return -ENOMEM;

        data = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        data->client = client;

        data->map = devm_regmap_init_i2c(client, &pa12203001_regmap_config);
        if (IS_ERR(data->map))
                return PTR_ERR(data->map);

        mutex_init(&data->lock);

        indio_dev->info = &pa12203001_info;
        indio_dev->name = PA12203001_DRIVER_NAME;
        indio_dev->channels = pa12203001_channels;
        indio_dev->num_channels = ARRAY_SIZE(pa12203001_channels);
        indio_dev->modes = INDIO_DIRECT_MODE;

        ret = pa12203001_init(indio_dev);
        if (ret < 0)
                return ret;

        ret = pa12203001_power_chip(indio_dev, PA12203001_CHIP_ENABLE);
        if (ret < 0)
                return ret;

        ret = pm_runtime_set_active(&client->dev);
        if (ret < 0)
                goto out_err;

        pm_runtime_enable(&client->dev);
        pm_runtime_set_autosuspend_delay(&client->dev,
                                         PA12203001_SLEEP_DELAY_MS);
        pm_runtime_use_autosuspend(&client->dev);

        ret = iio_device_register(indio_dev);
        if (ret < 0)
                goto out_err;

        return 0;

out_err:
        pa12203001_power_chip(indio_dev, PA12203001_CHIP_DISABLE);
        return ret;
}

static void pa12203001_remove(struct i2c_client *client)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
        int ret;

        iio_device_unregister(indio_dev);

        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);

        ret = pa12203001_power_chip(indio_dev, PA12203001_CHIP_DISABLE);
        if (ret)
                dev_warn(&client->dev, "Failed to power down (%pe)\n",
                         ERR_PTR(ret));
}

#if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM)
static int pa12203001_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

        return pa12203001_power_chip(indio_dev, PA12203001_CHIP_DISABLE);
}
#endif

#ifdef CONFIG_PM_SLEEP
static int pa12203001_resume(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

        return pa12203001_power_chip(indio_dev, PA12203001_CHIP_ENABLE);
}
#endif

#ifdef CONFIG_PM
static int pa12203001_runtime_resume(struct device *dev)
{
        struct pa12203001_data *data;

        data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

        mutex_lock(&data->lock);
        if (data->als_needs_enable) {
                pa12203001_als_enable(data, PA12203001_ALS_EN_MASK);
                data->als_needs_enable = false;
        }
        if (data->px_needs_enable) {
                pa12203001_px_enable(data, PA12203001_PX_EN_MASK);
                data->px_needs_enable = false;
        }
        mutex_unlock(&data->lock);

        return 0;
}
#endif

static const struct dev_pm_ops pa12203001_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(pa12203001_suspend, pa12203001_resume)
        SET_RUNTIME_PM_OPS(pa12203001_suspend, pa12203001_runtime_resume, NULL)
};

static const struct acpi_device_id pa12203001_acpi_match[] = {
        { "TXCPA122", 0 },
        { }
};

MODULE_DEVICE_TABLE(acpi, pa12203001_acpi_match);

static const struct i2c_device_id pa12203001_id[] = {
                { "txcpa122" },
                { }
};

MODULE_DEVICE_TABLE(i2c, pa12203001_id);

static struct i2c_driver pa12203001_driver = {
        .driver = {
                .name = PA12203001_DRIVER_NAME,
                .pm = &pa12203001_pm_ops,
                .acpi_match_table = pa12203001_acpi_match,
        },
        .probe = pa12203001_probe,
        .remove = pa12203001_remove,
        .id_table = pa12203001_id,

};
module_i2c_driver(pa12203001_driver);

MODULE_AUTHOR("Adriana Reus <adriana.reus@intel.com>");
MODULE_DESCRIPTION("Driver for TXC PA12203001 Proximity and Light Sensor");
MODULE_LICENSE("GPL v2");