// SPDX-License-Identifier: GPL-2.0-only
/*
 * isl29125.c - Support for Intersil ISL29125 RGB light sensor
 *
 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * RGB light sensor with 16-bit channels for red, green, blue);
 * 7-bit I2C slave address 0x44
 *
 * TODO: interrupt support, IR compensation, thresholds, 12bit
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/pm.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>

#define ISL29125_DRV_NAME "isl29125"

#define ISL29125_DEVICE_ID 0x00
#define ISL29125_CONF1 0x01
#define ISL29125_CONF2 0x02
#define ISL29125_CONF3 0x03
#define ISL29125_STATUS 0x08
#define ISL29125_GREEN_DATA 0x09
#define ISL29125_RED_DATA 0x0b
#define ISL29125_BLUE_DATA 0x0d

#define ISL29125_ID 0x7d

#define ISL29125_MODE_MASK GENMASK(2, 0)
#define ISL29125_MODE_PD 0x0
#define ISL29125_MODE_G 0x1
#define ISL29125_MODE_R 0x2
#define ISL29125_MODE_B 0x3
#define ISL29125_MODE_RGB 0x5

#define ISL29125_SENSING_RANGE_0 5722   /* 375 lux full range */
#define ISL29125_SENSING_RANGE_1 152590 /* 10k lux full range */

#define ISL29125_MODE_RANGE BIT(3)

#define ISL29125_STATUS_CONV BIT(1)

struct isl29125_data {
        struct i2c_client *client;
        u8 conf1;
};

#define ISL29125_CHANNEL(_color, _si) { \
        .type = IIO_INTENSITY, \
        .modified = 1, \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
        .channel2 = IIO_MOD_LIGHT_##_color, \
        .scan_index = _si, \
        .scan_type = { \
                .sign = 'u', \
                .realbits = 16, \
                .storagebits = 16, \
                .endianness = IIO_CPU, \
        }, \
}

static const struct iio_chan_spec isl29125_channels[] = {
        ISL29125_CHANNEL(GREEN, 0),
        ISL29125_CHANNEL(RED, 1),
        ISL29125_CHANNEL(BLUE, 2),
        IIO_CHAN_SOFT_TIMESTAMP(3),
};

static const struct {
        u8 mode, data;
} isl29125_regs[] = {
        {ISL29125_MODE_G, ISL29125_GREEN_DATA},
        {ISL29125_MODE_R, ISL29125_RED_DATA},
        {ISL29125_MODE_B, ISL29125_BLUE_DATA},
};

static int isl29125_read_data(struct isl29125_data *data, int si)
{
        int tries = 5;
        int ret;

        ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                data->conf1 | isl29125_regs[si].mode);
        if (ret < 0)
                return ret;

        msleep(101);

        while (tries--) {
                ret = i2c_smbus_read_byte_data(data->client, ISL29125_STATUS);
                if (ret < 0)
                        goto fail;
                if (ret & ISL29125_STATUS_CONV)
                        break;
                msleep(20);
        }

        if (tries < 0) {
                dev_err(&data->client->dev, "data not ready\n");
                ret = -EIO;
                goto fail;
        }

        ret = i2c_smbus_read_word_data(data->client, isl29125_regs[si].data);

fail:
        i2c_smbus_write_byte_data(data->client, ISL29125_CONF1, data->conf1);
        return ret;
}

static int isl29125_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val, int *val2, long mask)
{
        struct isl29125_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = isl29125_read_data(data, chan->scan_index);
                iio_device_release_direct(indio_dev);
                if (ret < 0)
                        return ret;
                *val = ret;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
                if (data->conf1 & ISL29125_MODE_RANGE)
                        *val2 = ISL29125_SENSING_RANGE_1; /*10k lux full range*/
                else
                        *val2 = ISL29125_SENSING_RANGE_0; /*375 lux full range*/
                return IIO_VAL_INT_PLUS_MICRO;
        }
        return -EINVAL;
}

static int isl29125_write_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int val, int val2, long mask)
{
        struct isl29125_data *data = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                if (val != 0)
                        return -EINVAL;
                if (val2 == ISL29125_SENSING_RANGE_1)
                        data->conf1 |= ISL29125_MODE_RANGE;
                else if (val2 == ISL29125_SENSING_RANGE_0)
                        data->conf1 &= ~ISL29125_MODE_RANGE;
                else
                        return -EINVAL;
                return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                        data->conf1);
        default:
                return -EINVAL;
        }
}

static irqreturn_t isl29125_trigger_handler(int irq, void *p)
{
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct isl29125_data *data = iio_priv(indio_dev);
        int i, j = 0;
        /* Ensure timestamp is naturally aligned */
        struct {
                u16 chans[3];
                aligned_s64 timestamp;
        } scan = { };

        iio_for_each_active_channel(indio_dev, i) {
                int ret = i2c_smbus_read_word_data(data->client,
                        isl29125_regs[i].data);
                if (ret < 0)
                        goto done;

                scan.chans[j++] = ret;
        }

        iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
                iio_get_time_ns(indio_dev));

done:
        iio_trigger_notify_done(indio_dev->trig);

        return IRQ_HANDLED;
}

static IIO_CONST_ATTR(scale_available, "0.005722 0.152590");

static struct attribute *isl29125_attributes[] = {
        &iio_const_attr_scale_available.dev_attr.attr,
        NULL
};

static const struct attribute_group isl29125_attribute_group = {
        .attrs = isl29125_attributes,
};

static const struct iio_info isl29125_info = {
        .read_raw = isl29125_read_raw,
        .write_raw = isl29125_write_raw,
        .attrs = &isl29125_attribute_group,
};

static int isl29125_buffer_postenable(struct iio_dev *indio_dev)
{
        struct isl29125_data *data = iio_priv(indio_dev);

        data->conf1 |= ISL29125_MODE_RGB;
        return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                data->conf1);
}

static int isl29125_buffer_predisable(struct iio_dev *indio_dev)
{
        struct isl29125_data *data = iio_priv(indio_dev);

        data->conf1 &= ~ISL29125_MODE_MASK;
        data->conf1 |= ISL29125_MODE_PD;
        return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                data->conf1);
}

static const struct iio_buffer_setup_ops isl29125_buffer_setup_ops = {
        .postenable = isl29125_buffer_postenable,
        .predisable = isl29125_buffer_predisable,
};

static int isl29125_probe(struct i2c_client *client)
{
        struct isl29125_data *data;
        struct iio_dev *indio_dev;
        int ret;

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

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

        indio_dev->info = &isl29125_info;
        indio_dev->name = ISL29125_DRV_NAME;
        indio_dev->channels = isl29125_channels;
        indio_dev->num_channels = ARRAY_SIZE(isl29125_channels);
        indio_dev->modes = INDIO_DIRECT_MODE;

        ret = i2c_smbus_read_byte_data(data->client, ISL29125_DEVICE_ID);
        if (ret < 0)
                return ret;
        if (ret != ISL29125_ID)
                return -ENODEV;

        data->conf1 = ISL29125_MODE_PD | ISL29125_MODE_RANGE;
        ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                data->conf1);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(data->client, ISL29125_STATUS, 0);
        if (ret < 0)
                return ret;

        ret = iio_triggered_buffer_setup(indio_dev, NULL,
                isl29125_trigger_handler, &isl29125_buffer_setup_ops);
        if (ret < 0)
                return ret;

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

        return 0;

buffer_cleanup:
        iio_triggered_buffer_cleanup(indio_dev);
        return ret;
}

static int isl29125_powerdown(struct isl29125_data *data)
{
        return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                (data->conf1 & ~ISL29125_MODE_MASK) | ISL29125_MODE_PD);
}

static void isl29125_remove(struct i2c_client *client)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(client);

        iio_device_unregister(indio_dev);
        iio_triggered_buffer_cleanup(indio_dev);
        isl29125_powerdown(iio_priv(indio_dev));
}

static int isl29125_suspend(struct device *dev)
{
        struct isl29125_data *data = iio_priv(i2c_get_clientdata(
                to_i2c_client(dev)));
        return isl29125_powerdown(data);
}

static int isl29125_resume(struct device *dev)
{
        struct isl29125_data *data = iio_priv(i2c_get_clientdata(
                to_i2c_client(dev)));
        return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
                data->conf1);
}

static DEFINE_SIMPLE_DEV_PM_OPS(isl29125_pm_ops, isl29125_suspend,
                                isl29125_resume);

static const struct i2c_device_id isl29125_id[] = {
        { "isl29125" },
        { }
};
MODULE_DEVICE_TABLE(i2c, isl29125_id);

static struct i2c_driver isl29125_driver = {
        .driver = {
                .name   = ISL29125_DRV_NAME,
                .pm     = pm_sleep_ptr(&isl29125_pm_ops),
        },
        .probe          = isl29125_probe,
        .remove         = isl29125_remove,
        .id_table       = isl29125_id,
};
module_i2c_driver(isl29125_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("ISL29125 RGB light sensor driver");
MODULE_LICENSE("GPL");