root/drivers/iio/light/iqs621-als.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Azoteq IQS621/622 Ambient Light Sensors
 *
 * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
 */

#include <linux/device.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/mfd/iqs62x.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define IQS621_ALS_FLAGS_LIGHT                  BIT(7)
#define IQS621_ALS_FLAGS_RANGE                  GENMASK(3, 0)

#define IQS621_ALS_UI_OUT                       0x17

#define IQS621_ALS_THRESH_DARK                  0x80
#define IQS621_ALS_THRESH_LIGHT                 0x81

#define IQS622_IR_RANGE                         0x15
#define IQS622_IR_FLAGS                         0x16
#define IQS622_IR_FLAGS_TOUCH                   BIT(1)
#define IQS622_IR_FLAGS_PROX                    BIT(0)

#define IQS622_IR_UI_OUT                        0x17

#define IQS622_IR_THRESH_PROX                   0x91
#define IQS622_IR_THRESH_TOUCH                  0x92

struct iqs621_als_private {
        struct iqs62x_core *iqs62x;
        struct iio_dev *indio_dev;
        struct notifier_block notifier;
        struct mutex lock;
        bool light_en;
        bool range_en;
        bool prox_en;
        u8 als_flags;
        u8 ir_flags_mask;
        u8 ir_flags;
        u8 thresh_light;
        u8 thresh_dark;
        u8 thresh_prox;
};

static int iqs621_als_init(struct iqs621_als_private *iqs621_als)
{
        struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
        unsigned int event_mask = 0;
        int ret;

        switch (iqs621_als->ir_flags_mask) {
        case IQS622_IR_FLAGS_TOUCH:
                ret = regmap_write(iqs62x->regmap, IQS622_IR_THRESH_TOUCH,
                                   iqs621_als->thresh_prox);
                break;

        case IQS622_IR_FLAGS_PROX:
                ret = regmap_write(iqs62x->regmap, IQS622_IR_THRESH_PROX,
                                   iqs621_als->thresh_prox);
                break;

        default:
                ret = regmap_write(iqs62x->regmap, IQS621_ALS_THRESH_LIGHT,
                                   iqs621_als->thresh_light);
                if (ret)
                        return ret;

                ret = regmap_write(iqs62x->regmap, IQS621_ALS_THRESH_DARK,
                                   iqs621_als->thresh_dark);
        }

        if (ret)
                return ret;

        if (iqs621_als->light_en || iqs621_als->range_en)
                event_mask |= iqs62x->dev_desc->als_mask;

        if (iqs621_als->prox_en)
                event_mask |= iqs62x->dev_desc->ir_mask;

        return regmap_clear_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
                                 event_mask);
}

static int iqs621_als_notifier(struct notifier_block *notifier,
                               unsigned long event_flags, void *context)
{
        struct iqs62x_event_data *event_data = context;
        struct iqs621_als_private *iqs621_als;
        struct iio_dev *indio_dev;
        bool light_new, light_old;
        bool prox_new, prox_old;
        u8 range_new, range_old;
        s64 timestamp;
        int ret;

        iqs621_als = container_of(notifier, struct iqs621_als_private,
                                  notifier);
        indio_dev = iqs621_als->indio_dev;
        timestamp = iio_get_time_ns(indio_dev);

        mutex_lock(&iqs621_als->lock);

        if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
                ret = iqs621_als_init(iqs621_als);
                if (ret) {
                        dev_err(indio_dev->dev.parent,
                                "Failed to re-initialize device: %d\n", ret);
                        ret = NOTIFY_BAD;
                } else {
                        ret = NOTIFY_OK;
                }

                goto err_mutex;
        }

        if (!iqs621_als->light_en && !iqs621_als->range_en &&
            !iqs621_als->prox_en) {
                ret = NOTIFY_DONE;
                goto err_mutex;
        }

        /* IQS621 only */
        light_new = event_data->als_flags & IQS621_ALS_FLAGS_LIGHT;
        light_old = iqs621_als->als_flags & IQS621_ALS_FLAGS_LIGHT;

        if (iqs621_als->light_en && light_new && !light_old)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_RISING),
                               timestamp);
        else if (iqs621_als->light_en && !light_new && light_old)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_FALLING),
                               timestamp);

        /* IQS621 and IQS622 */
        range_new = event_data->als_flags & IQS621_ALS_FLAGS_RANGE;
        range_old = iqs621_als->als_flags & IQS621_ALS_FLAGS_RANGE;

        if (iqs621_als->range_en && (range_new > range_old))
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
                                                    IIO_EV_TYPE_CHANGE,
                                                    IIO_EV_DIR_RISING),
                               timestamp);
        else if (iqs621_als->range_en && (range_new < range_old))
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
                                                    IIO_EV_TYPE_CHANGE,
                                                    IIO_EV_DIR_FALLING),
                               timestamp);

        /* IQS622 only */
        prox_new = event_data->ir_flags & iqs621_als->ir_flags_mask;
        prox_old = iqs621_als->ir_flags & iqs621_als->ir_flags_mask;

        if (iqs621_als->prox_en && prox_new && !prox_old)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_RISING),
                               timestamp);
        else if (iqs621_als->prox_en && !prox_new && prox_old)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_FALLING),
                               timestamp);

        iqs621_als->als_flags = event_data->als_flags;
        iqs621_als->ir_flags = event_data->ir_flags;
        ret = NOTIFY_OK;

err_mutex:
        mutex_unlock(&iqs621_als->lock);

        return ret;
}

static void iqs621_als_notifier_unregister(void *context)
{
        struct iqs621_als_private *iqs621_als = context;
        struct iio_dev *indio_dev = iqs621_als->indio_dev;
        int ret;

        ret = blocking_notifier_chain_unregister(&iqs621_als->iqs62x->nh,
                                                 &iqs621_als->notifier);
        if (ret)
                dev_err(indio_dev->dev.parent,
                        "Failed to unregister notifier: %d\n", ret);
}

static int iqs621_als_read_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int *val, int *val2, long mask)
{
        struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
        struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
        int ret;
        __le16 val_buf;

        switch (chan->type) {
        case IIO_INTENSITY:
                ret = regmap_read(iqs62x->regmap, chan->address, val);
                if (ret)
                        return ret;

                *val &= IQS621_ALS_FLAGS_RANGE;
                return IIO_VAL_INT;

        case IIO_PROXIMITY:
        case IIO_LIGHT:
                ret = regmap_raw_read(iqs62x->regmap, chan->address, &val_buf,
                                      sizeof(val_buf));
                if (ret)
                        return ret;

                *val = le16_to_cpu(val_buf);
                return IIO_VAL_INT;

        default:
                return -EINVAL;
        }
}

static int iqs621_als_read_event_config(struct iio_dev *indio_dev,
                                        const struct iio_chan_spec *chan,
                                        enum iio_event_type type,
                                        enum iio_event_direction dir)
{
        struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
        int ret;

        mutex_lock(&iqs621_als->lock);

        switch (chan->type) {
        case IIO_LIGHT:
                ret = iqs621_als->light_en;
                break;

        case IIO_INTENSITY:
                ret = iqs621_als->range_en;
                break;

        case IIO_PROXIMITY:
                ret = iqs621_als->prox_en;
                break;

        default:
                ret = -EINVAL;
        }

        mutex_unlock(&iqs621_als->lock);

        return ret;
}

static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
                                         const struct iio_chan_spec *chan,
                                         enum iio_event_type type,
                                         enum iio_event_direction dir,
                                         bool state)
{
        struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
        struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
        unsigned int val;
        int ret;

        mutex_lock(&iqs621_als->lock);

        ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->als_flags, &val);
        if (ret)
                goto err_mutex;
        iqs621_als->als_flags = val;

        switch (chan->type) {
        case IIO_LIGHT:
                ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
                                         iqs62x->dev_desc->als_mask,
                                         iqs621_als->range_en || state ? 0 :
                                                                         0xFF);
                if (!ret)
                        iqs621_als->light_en = state;
                break;

        case IIO_INTENSITY:
                ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
                                         iqs62x->dev_desc->als_mask,
                                         iqs621_als->light_en || state ? 0 :
                                                                         0xFF);
                if (!ret)
                        iqs621_als->range_en = state;
                break;

        case IIO_PROXIMITY:
                ret = regmap_read(iqs62x->regmap, IQS622_IR_FLAGS, &val);
                if (ret)
                        goto err_mutex;
                iqs621_als->ir_flags = val;

                ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
                                         iqs62x->dev_desc->ir_mask,
                                         state ? 0 : 0xFF);
                if (!ret)
                        iqs621_als->prox_en = state;
                break;

        default:
                ret = -EINVAL;
        }

err_mutex:
        mutex_unlock(&iqs621_als->lock);

        return ret;
}

static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
                                       const struct iio_chan_spec *chan,
                                       enum iio_event_type type,
                                       enum iio_event_direction dir,
                                       enum iio_event_info info,
                                       int *val, int *val2)
{
        struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
        int ret = IIO_VAL_INT;

        mutex_lock(&iqs621_als->lock);

        switch (dir) {
        case IIO_EV_DIR_RISING:
                *val = iqs621_als->thresh_light * 16;
                break;

        case IIO_EV_DIR_FALLING:
                *val = iqs621_als->thresh_dark * 4;
                break;

        case IIO_EV_DIR_EITHER:
                if (iqs621_als->ir_flags_mask == IQS622_IR_FLAGS_TOUCH)
                        *val = iqs621_als->thresh_prox * 4;
                else
                        *val = iqs621_als->thresh_prox;
                break;

        default:
                ret = -EINVAL;
        }

        mutex_unlock(&iqs621_als->lock);

        return ret;
}

static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
                                        const struct iio_chan_spec *chan,
                                        enum iio_event_type type,
                                        enum iio_event_direction dir,
                                        enum iio_event_info info,
                                        int val, int val2)
{
        struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
        struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
        unsigned int thresh_reg, thresh_val;
        u8 ir_flags_mask, *thresh_cache;
        int ret = -EINVAL;

        mutex_lock(&iqs621_als->lock);

        switch (dir) {
        case IIO_EV_DIR_RISING:
                thresh_reg = IQS621_ALS_THRESH_LIGHT;
                thresh_val = val / 16;

                thresh_cache = &iqs621_als->thresh_light;
                ir_flags_mask = 0;
                break;

        case IIO_EV_DIR_FALLING:
                thresh_reg = IQS621_ALS_THRESH_DARK;
                thresh_val = val / 4;

                thresh_cache = &iqs621_als->thresh_dark;
                ir_flags_mask = 0;
                break;

        case IIO_EV_DIR_EITHER:
                /*
                 * The IQS622 supports two detection thresholds, both measured
                 * in the same arbitrary units reported by read_raw: proximity
                 * (0 through 255 in steps of 1), and touch (0 through 1020 in
                 * steps of 4).
                 *
                 * Based on the single detection threshold chosen by the user,
                 * select the hardware threshold that gives the best trade-off
                 * between range and resolution.
                 *
                 * By default, the close-range (but coarse) touch threshold is
                 * chosen during probe.
                 */
                switch (val) {
                case 0 ... 255:
                        thresh_reg = IQS622_IR_THRESH_PROX;
                        thresh_val = val;

                        ir_flags_mask = IQS622_IR_FLAGS_PROX;
                        break;

                case 256 ... 1020:
                        thresh_reg = IQS622_IR_THRESH_TOUCH;
                        thresh_val = val / 4;

                        ir_flags_mask = IQS622_IR_FLAGS_TOUCH;
                        break;

                default:
                        goto err_mutex;
                }

                thresh_cache = &iqs621_als->thresh_prox;
                break;

        default:
                goto err_mutex;
        }

        if (thresh_val > 0xFF)
                goto err_mutex;

        ret = regmap_write(iqs62x->regmap, thresh_reg, thresh_val);
        if (ret)
                goto err_mutex;

        *thresh_cache = thresh_val;
        iqs621_als->ir_flags_mask = ir_flags_mask;

err_mutex:
        mutex_unlock(&iqs621_als->lock);

        return ret;
}

static const struct iio_info iqs621_als_info = {
        .read_raw = &iqs621_als_read_raw,
        .read_event_config = iqs621_als_read_event_config,
        .write_event_config = iqs621_als_write_event_config,
        .read_event_value = iqs621_als_read_event_value,
        .write_event_value = iqs621_als_write_event_value,
};

static const struct iio_event_spec iqs621_als_range_events[] = {
        {
                .type = IIO_EV_TYPE_CHANGE,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE),
        },
};

static const struct iio_event_spec iqs621_als_light_events[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE),
        },
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_RISING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        },
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_FALLING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        },
};

static const struct iio_chan_spec iqs621_als_channels[] = {
        {
                .type = IIO_INTENSITY,
                .address = IQS621_ALS_FLAGS,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .event_spec = iqs621_als_range_events,
                .num_event_specs = ARRAY_SIZE(iqs621_als_range_events),
        },
        {
                .type = IIO_LIGHT,
                .address = IQS621_ALS_UI_OUT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
                .event_spec = iqs621_als_light_events,
                .num_event_specs = ARRAY_SIZE(iqs621_als_light_events),
        },
};

static const struct iio_event_spec iqs622_als_prox_events[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
                                 BIT(IIO_EV_INFO_VALUE),
        },
};

static const struct iio_chan_spec iqs622_als_channels[] = {
        {
                .type = IIO_INTENSITY,
                .channel2 = IIO_MOD_LIGHT_BOTH,
                .address = IQS622_ALS_FLAGS,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .event_spec = iqs621_als_range_events,
                .num_event_specs = ARRAY_SIZE(iqs621_als_range_events),
                .modified = true,
        },
        {
                .type = IIO_INTENSITY,
                .channel2 = IIO_MOD_LIGHT_IR,
                .address = IQS622_IR_RANGE,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .modified = true,
        },
        {
                .type = IIO_PROXIMITY,
                .address = IQS622_IR_UI_OUT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .event_spec = iqs622_als_prox_events,
                .num_event_specs = ARRAY_SIZE(iqs622_als_prox_events),
        },
};

static int iqs621_als_probe(struct platform_device *pdev)
{
        struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
        struct iqs621_als_private *iqs621_als;
        struct iio_dev *indio_dev;
        unsigned int val;
        int ret;

        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs621_als));
        if (!indio_dev)
                return -ENOMEM;

        iqs621_als = iio_priv(indio_dev);
        iqs621_als->iqs62x = iqs62x;
        iqs621_als->indio_dev = indio_dev;

        if (iqs62x->dev_desc->prod_num == IQS622_PROD_NUM) {
                ret = regmap_read(iqs62x->regmap, IQS622_IR_THRESH_TOUCH,
                                  &val);
                if (ret)
                        return ret;
                iqs621_als->thresh_prox = val;
                iqs621_als->ir_flags_mask = IQS622_IR_FLAGS_TOUCH;

                indio_dev->channels = iqs622_als_channels;
                indio_dev->num_channels = ARRAY_SIZE(iqs622_als_channels);
        } else {
                ret = regmap_read(iqs62x->regmap, IQS621_ALS_THRESH_LIGHT,
                                  &val);
                if (ret)
                        return ret;
                iqs621_als->thresh_light = val;

                ret = regmap_read(iqs62x->regmap, IQS621_ALS_THRESH_DARK,
                                  &val);
                if (ret)
                        return ret;
                iqs621_als->thresh_dark = val;

                indio_dev->channels = iqs621_als_channels;
                indio_dev->num_channels = ARRAY_SIZE(iqs621_als_channels);
        }

        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->name = iqs62x->dev_desc->dev_name;
        indio_dev->info = &iqs621_als_info;

        mutex_init(&iqs621_als->lock);

        iqs621_als->notifier.notifier_call = iqs621_als_notifier;
        ret = blocking_notifier_chain_register(&iqs621_als->iqs62x->nh,
                                               &iqs621_als->notifier);
        if (ret) {
                dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
                return ret;
        }

        ret = devm_add_action_or_reset(&pdev->dev,
                                       iqs621_als_notifier_unregister,
                                       iqs621_als);
        if (ret)
                return ret;

        return devm_iio_device_register(&pdev->dev, indio_dev);
}

static struct platform_driver iqs621_als_platform_driver = {
        .driver = {
                .name = "iqs621-als",
        },
        .probe = iqs621_als_probe,
};
module_platform_driver(iqs621_als_platform_driver);

MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
MODULE_DESCRIPTION("Azoteq IQS621/622 Ambient Light Sensors");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:iqs621-als");