// SPDX-License-Identifier: GPL-2.0
/*
 * cros_ec_light_prox - Driver for light and prox sensors behing CrosEC.
 *
 * Copyright (C) 2017 Google, Inc
 */

#include <linux/device.h>
#include <linux/iio/buffer.h>
#include <linux/iio/common/cros_ec_sensors_core.h>
#include <linux/iio/iio.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/*
 * We only represent one entry for light or proximity. EC is merging different
 * light sensors to return the what the eye would see. For proximity, we
 * currently support only one light source.
 */
#define CROS_EC_LIGHT_PROX_MAX_CHANNELS (1 + 1)

/* State data for ec_sensors iio driver. */
struct cros_ec_light_prox_state {
        /* Shared by all sensors */
        struct cros_ec_sensors_core_state core;

        struct iio_chan_spec channels[CROS_EC_LIGHT_PROX_MAX_CHANNELS];
};

static int cros_ec_light_prox_read(struct iio_dev *indio_dev,
                                   struct iio_chan_spec const *chan,
                                   int *val, int *val2, long mask)
{
        struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
        u16 data = 0;
        s64 val64;
        int ret;
        int idx = chan->scan_index;

        mutex_lock(&st->core.cmd_lock);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (chan->type == IIO_PROXIMITY) {
                        ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
                                                     (s16 *)&data);
                        if (ret)
                                break;
                        *val = data;
                        ret = IIO_VAL_INT;
                } else {
                        ret = -EINVAL;
                }
                break;
        case IIO_CHAN_INFO_PROCESSED:
                if (chan->type == IIO_LIGHT) {
                        ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
                                                     (s16 *)&data);
                        if (ret)
                                break;
                        /*
                         * The data coming from the light sensor is
                         * pre-processed and represents the ambient light
                         * illuminance reading expressed in lux.
                         */
                        *val = data;
                        ret = IIO_VAL_INT;
                } else {
                        ret = -EINVAL;
                }
                break;
        case IIO_CHAN_INFO_CALIBBIAS:
                st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
                st->core.param.sensor_offset.flags = 0;

                ret = cros_ec_motion_send_host_cmd(&st->core, 0);
                if (ret)
                        break;

                /* Save values */
                st->core.calib[0].offset =
                        st->core.resp->sensor_offset.offset[0];

                *val = st->core.calib[idx].offset;
                ret = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_CALIBSCALE:
                /*
                 * RANGE is used for calibration
                 * scale is a number x.y, where x is coded on 16 bits,
                 * y coded on 16 bits, between 0 and 9999.
                 */
                st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
                st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;

                ret = cros_ec_motion_send_host_cmd(&st->core, 0);
                if (ret)
                        break;

                val64 = st->core.resp->sensor_range.ret;
                *val = val64 >> 16;
                *val2 = (val64 & 0xffff) * 100;
                ret = IIO_VAL_INT_PLUS_MICRO;
                break;
        default:
                ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
                                                mask);
                break;
        }

        mutex_unlock(&st->core.cmd_lock);

        return ret;
}

static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int val, int val2, long mask)
{
        struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
        int ret;
        int idx = chan->scan_index;

        mutex_lock(&st->core.cmd_lock);

        switch (mask) {
        case IIO_CHAN_INFO_CALIBBIAS:
                st->core.calib[idx].offset = val;
                /* Send to EC for each axis, even if not complete */
                st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
                st->core.param.sensor_offset.flags = MOTION_SENSE_SET_OFFSET;
                st->core.param.sensor_offset.offset[0] =
                        st->core.calib[0].offset;
                st->core.param.sensor_offset.temp =
                                        EC_MOTION_SENSE_INVALID_CALIB_TEMP;
                ret = cros_ec_motion_send_host_cmd(&st->core, 0);
                break;
        case IIO_CHAN_INFO_CALIBSCALE:
                st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
                st->core.curr_range = (val << 16) | (val2 / 100);
                st->core.param.sensor_range.data = st->core.curr_range;
                ret = cros_ec_motion_send_host_cmd(&st->core, 0);
                if (ret == 0)
                        st->core.range_updated = true;
                break;
        default:
                ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
                                                 mask);
                break;
        }

        mutex_unlock(&st->core.cmd_lock);

        return ret;
}

static const struct iio_info cros_ec_light_prox_info = {
        .read_raw = &cros_ec_light_prox_read,
        .write_raw = &cros_ec_light_prox_write,
        .read_avail = &cros_ec_sensors_core_read_avail,
};

static int cros_ec_light_prox_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct iio_dev *indio_dev;
        struct cros_ec_light_prox_state *state;
        struct iio_chan_spec *channel;
        int ret;

        indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
        if (!indio_dev)
                return -ENOMEM;

        ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
                                        cros_ec_sensors_capture);
        if (ret)
                return ret;

        indio_dev->info = &cros_ec_light_prox_info;
        state = iio_priv(indio_dev);
        channel = state->channels;

        /* Common part */
        channel->info_mask_shared_by_all =
                BIT(IIO_CHAN_INFO_SAMP_FREQ);
        channel->info_mask_shared_by_all_available =
                BIT(IIO_CHAN_INFO_SAMP_FREQ);
        channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
        channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
        channel->scan_type.shift = 0;
        channel->scan_index = 0;
        channel->ext_info = cros_ec_sensors_ext_info;
        channel->scan_type.sign = 'u';

        /* Sensor specific */
        switch (state->core.type) {
        case MOTIONSENSE_TYPE_LIGHT:
                channel->type = IIO_LIGHT;
                channel->info_mask_separate =
                        BIT(IIO_CHAN_INFO_PROCESSED) |
                        BIT(IIO_CHAN_INFO_CALIBBIAS) |
                        BIT(IIO_CHAN_INFO_CALIBSCALE);
                break;
        case MOTIONSENSE_TYPE_PROX:
                channel->type = IIO_PROXIMITY;
                channel->info_mask_separate =
                        BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_CALIBBIAS) |
                        BIT(IIO_CHAN_INFO_CALIBSCALE);
                break;
        default:
                dev_warn(dev, "Unknown motion sensor\n");
                return -EINVAL;
        }

        /* Timestamp */
        channel++;
        channel->type = IIO_TIMESTAMP;
        channel->channel = -1;
        channel->scan_index = 1;
        channel->scan_type.sign = 's';
        channel->scan_type.realbits = 64;
        channel->scan_type.storagebits = 64;

        indio_dev->channels = state->channels;

        indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;

        state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;

        return cros_ec_sensors_core_register(dev, indio_dev,
                                             cros_ec_sensors_push_data);
}

static const struct platform_device_id cros_ec_light_prox_ids[] = {
        {
                .name = "cros-ec-prox",
        },
        {
                .name = "cros-ec-light",
        },
        { }
};
MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);

static struct platform_driver cros_ec_light_prox_platform_driver = {
        .driver = {
                .name   = "cros-ec-light-prox",
                .pm     = &cros_ec_sensors_pm_ops,
        },
        .probe          = cros_ec_light_prox_probe,
        .id_table       = cros_ec_light_prox_ids,
};
module_platform_driver(cros_ec_light_prox_platform_driver);

MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
MODULE_LICENSE("GPL v2");