root/drivers/iio/light/lm3533-als.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lm3533-als.c -- LM3533 Ambient Light Sensor driver
 *
 * Copyright (C) 2011-2012 Texas Instruments
 *
 * Author: Johan Hovold <jhovold@gmail.com>
 */

#include <linux/atomic.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/mfd/core.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include <linux/mfd/lm3533.h>


#define LM3533_ALS_RESISTOR_MIN                 1
#define LM3533_ALS_RESISTOR_MAX                 127
#define LM3533_ALS_CHANNEL_CURRENT_MAX          2
#define LM3533_ALS_THRESH_MAX                   3
#define LM3533_ALS_ZONE_MAX                     4

#define LM3533_REG_ALS_RESISTOR_SELECT          0x30
#define LM3533_REG_ALS_CONF                     0x31
#define LM3533_REG_ALS_ZONE_INFO                0x34
#define LM3533_REG_ALS_READ_ADC_RAW             0x37
#define LM3533_REG_ALS_READ_ADC_AVERAGE         0x38
#define LM3533_REG_ALS_BOUNDARY_BASE            0x50
#define LM3533_REG_ALS_TARGET_BASE              0x60

#define LM3533_ALS_ENABLE_MASK                  0x01
#define LM3533_ALS_INPUT_MODE_MASK              0x02
#define LM3533_ALS_INT_ENABLE_MASK              0x01

#define LM3533_ALS_ZONE_SHIFT                   2
#define LM3533_ALS_ZONE_MASK                    0x1c

#define LM3533_ALS_FLAG_INT_ENABLED             1


struct lm3533_als {
        struct lm3533 *lm3533;
        struct platform_device *pdev;

        unsigned long flags;
        int irq;

        atomic_t zone;
        struct mutex thresh_mutex;
};


static int lm3533_als_get_adc(struct iio_dev *indio_dev, bool average,
                                                                int *adc)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 reg;
        u8 val;
        int ret;

        if (average)
                reg = LM3533_REG_ALS_READ_ADC_AVERAGE;
        else
                reg = LM3533_REG_ALS_READ_ADC_RAW;

        ret = lm3533_read(als->lm3533, reg, &val);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to read adc\n");
                return ret;
        }

        *adc = val;

        return 0;
}

static int _lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 val;
        int ret;

        ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO, &val);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to read zone\n");
                return ret;
        }

        val = (val & LM3533_ALS_ZONE_MASK) >> LM3533_ALS_ZONE_SHIFT;
        *zone = min_t(u8, val, LM3533_ALS_ZONE_MAX);

        return 0;
}

static int lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        int ret;

        if (test_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags)) {
                *zone = atomic_read(&als->zone);
        } else {
                ret = _lm3533_als_get_zone(indio_dev, zone);
                if (ret)
                        return ret;
        }

        return 0;
}

/*
 * channel      output channel 0..2
 * zone         zone 0..4
 */
static inline u8 lm3533_als_get_target_reg(unsigned channel, unsigned zone)
{
        return LM3533_REG_ALS_TARGET_BASE + 5 * channel + zone;
}

static int lm3533_als_get_target(struct iio_dev *indio_dev, unsigned channel,
                                                        unsigned zone, u8 *val)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 reg;
        int ret;

        if (channel > LM3533_ALS_CHANNEL_CURRENT_MAX)
                return -EINVAL;

        if (zone > LM3533_ALS_ZONE_MAX)
                return -EINVAL;

        reg = lm3533_als_get_target_reg(channel, zone);
        ret = lm3533_read(als->lm3533, reg, val);
        if (ret)
                dev_err(&indio_dev->dev, "failed to get target current\n");

        return ret;
}

static int lm3533_als_set_target(struct iio_dev *indio_dev, unsigned channel,
                                                        unsigned zone, u8 val)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 reg;
        int ret;

        if (channel > LM3533_ALS_CHANNEL_CURRENT_MAX)
                return -EINVAL;

        if (zone > LM3533_ALS_ZONE_MAX)
                return -EINVAL;

        reg = lm3533_als_get_target_reg(channel, zone);
        ret = lm3533_write(als->lm3533, reg, val);
        if (ret)
                dev_err(&indio_dev->dev, "failed to set target current\n");

        return ret;
}

static int lm3533_als_get_current(struct iio_dev *indio_dev, unsigned channel,
                                                                int *val)
{
        u8 zone;
        u8 target;
        int ret;

        ret = lm3533_als_get_zone(indio_dev, &zone);
        if (ret)
                return ret;

        ret = lm3533_als_get_target(indio_dev, channel, zone, &target);
        if (ret)
                return ret;

        *val = target;

        return 0;
}

static int lm3533_als_read_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int *val, int *val2, long mask)
{
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_LIGHT:
                        ret = lm3533_als_get_adc(indio_dev, false, val);
                        break;
                case IIO_CURRENT:
                        ret = lm3533_als_get_current(indio_dev, chan->channel,
                                                                        val);
                        break;
                default:
                        return -EINVAL;
                }
                break;
        case IIO_CHAN_INFO_AVERAGE_RAW:
                ret = lm3533_als_get_adc(indio_dev, true, val);
                break;
        default:
                return -EINVAL;
        }

        if (ret)
                return ret;

        return IIO_VAL_INT;
}

#define CHANNEL_CURRENT(_channel)                                       \
        {                                                               \
                .type           = IIO_CURRENT,                          \
                .channel        = _channel,                             \
                .indexed        = true,                                 \
                .output         = true,                                 \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
        }

static const struct iio_chan_spec lm3533_als_channels[] = {
        {
                .type           = IIO_LIGHT,
                .channel        = 0,
                .indexed        = true,
                .info_mask_separate = BIT(IIO_CHAN_INFO_AVERAGE_RAW) |
                                   BIT(IIO_CHAN_INFO_RAW),
        },
        CHANNEL_CURRENT(0),
        CHANNEL_CURRENT(1),
        CHANNEL_CURRENT(2),
};

static irqreturn_t lm3533_als_isr(int irq, void *dev_id)
{

        struct iio_dev *indio_dev = dev_id;
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 zone;
        int ret;

        /* Clear interrupt by reading the ALS zone register. */
        ret = _lm3533_als_get_zone(indio_dev, &zone);
        if (ret)
                goto out;

        atomic_set(&als->zone, zone);

        iio_push_event(indio_dev,
                       IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
                                            0,
                                            IIO_EV_TYPE_THRESH,
                                            IIO_EV_DIR_EITHER),
                       iio_get_time_ns(indio_dev));
out:
        return IRQ_HANDLED;
}

static int lm3533_als_set_int_mode(struct iio_dev *indio_dev, int enable)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 mask = LM3533_ALS_INT_ENABLE_MASK;
        u8 val;
        int ret;

        if (enable)
                val = mask;
        else
                val = 0;

        ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, val, mask);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to set int mode %d\n",
                                                                enable);
                return ret;
        }

        return 0;
}

static int lm3533_als_get_int_mode(struct iio_dev *indio_dev, int *enable)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 mask = LM3533_ALS_INT_ENABLE_MASK;
        u8 val;
        int ret;

        ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO, &val);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to get int mode\n");
                return ret;
        }

        *enable = !!(val & mask);

        return 0;
}

static inline u8 lm3533_als_get_threshold_reg(unsigned nr, bool raising)
{
        u8 offset = !raising;

        return LM3533_REG_ALS_BOUNDARY_BASE + 2 * nr + offset;
}

static int lm3533_als_get_threshold(struct iio_dev *indio_dev, unsigned nr,
                                                        bool raising, u8 *val)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 reg;
        int ret;

        if (nr > LM3533_ALS_THRESH_MAX)
                return -EINVAL;

        reg = lm3533_als_get_threshold_reg(nr, raising);
        ret = lm3533_read(als->lm3533, reg, val);
        if (ret)
                dev_err(&indio_dev->dev, "failed to get threshold\n");

        return ret;
}

static int lm3533_als_set_threshold(struct iio_dev *indio_dev, unsigned nr,
                                                        bool raising, u8 val)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 val2;
        u8 reg, reg2;
        int ret;

        if (nr > LM3533_ALS_THRESH_MAX)
                return -EINVAL;

        reg = lm3533_als_get_threshold_reg(nr, raising);
        reg2 = lm3533_als_get_threshold_reg(nr, !raising);

        mutex_lock(&als->thresh_mutex);
        ret = lm3533_read(als->lm3533, reg2, &val2);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to get threshold\n");
                goto out;
        }
        /*
         * This device does not allow negative hysteresis (in fact, it uses
         * whichever value is smaller as the lower bound) so we need to make
         * sure that thresh_falling <= thresh_raising.
         */
        if ((raising && (val < val2)) || (!raising && (val > val2))) {
                ret = -EINVAL;
                goto out;
        }

        ret = lm3533_write(als->lm3533, reg, val);
        if (ret) {
                dev_err(&indio_dev->dev, "failed to set threshold\n");
                goto out;
        }
out:
        mutex_unlock(&als->thresh_mutex);

        return ret;
}

static int lm3533_als_get_hysteresis(struct iio_dev *indio_dev, unsigned nr,
                                                                u8 *val)
{
        struct lm3533_als *als = iio_priv(indio_dev);
        u8 falling;
        u8 raising;
        int ret;

        if (nr > LM3533_ALS_THRESH_MAX)
                return -EINVAL;

        mutex_lock(&als->thresh_mutex);
        ret = lm3533_als_get_threshold(indio_dev, nr, false, &falling);
        if (ret)
                goto out;
        ret = lm3533_als_get_threshold(indio_dev, nr, true, &raising);
        if (ret)
                goto out;

        *val = raising - falling;
out:
        mutex_unlock(&als->thresh_mutex);

        return ret;
}

static ssize_t show_thresh_either_en(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct lm3533_als *als = iio_priv(indio_dev);
        int enable;
        int ret;

        if (als->irq) {
                ret = lm3533_als_get_int_mode(indio_dev, &enable);
                if (ret)
                        return ret;
        } else {
                enable = 0;
        }

        return sysfs_emit(buf, "%u\n", enable);
}

static ssize_t store_thresh_either_en(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct lm3533_als *als = iio_priv(indio_dev);
        unsigned long enable;
        bool int_enabled;
        u8 zone;
        int ret;

        if (!als->irq)
                return -EBUSY;

        if (kstrtoul(buf, 0, &enable))
                return -EINVAL;

        int_enabled = test_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);

        if (enable && !int_enabled) {
                ret = lm3533_als_get_zone(indio_dev, &zone);
                if (ret)
                        return ret;

                atomic_set(&als->zone, zone);

                set_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);
        }

        ret = lm3533_als_set_int_mode(indio_dev, enable);
        if (ret) {
                if (!int_enabled)
                        clear_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);

                return ret;
        }

        if (!enable)
                clear_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);

        return len;
}

static ssize_t show_zone(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        u8 zone;
        int ret;

        ret = lm3533_als_get_zone(indio_dev, &zone);
        if (ret)
                return ret;

        return sysfs_emit(buf, "%u\n", zone);
}

enum lm3533_als_attribute_type {
        LM3533_ATTR_TYPE_HYSTERESIS,
        LM3533_ATTR_TYPE_TARGET,
        LM3533_ATTR_TYPE_THRESH_FALLING,
        LM3533_ATTR_TYPE_THRESH_RAISING,
};

struct lm3533_als_attribute {
        struct device_attribute dev_attr;
        enum lm3533_als_attribute_type type;
        u8 val1;
        u8 val2;
};

static inline struct lm3533_als_attribute *
to_lm3533_als_attr(struct device_attribute *attr)
{
        return container_of(attr, struct lm3533_als_attribute, dev_attr);
}

static ssize_t show_als_attr(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
        u8 val;
        int ret;

        switch (als_attr->type) {
        case LM3533_ATTR_TYPE_HYSTERESIS:
                ret = lm3533_als_get_hysteresis(indio_dev, als_attr->val1,
                                                                        &val);
                break;
        case LM3533_ATTR_TYPE_TARGET:
                ret = lm3533_als_get_target(indio_dev, als_attr->val1,
                                                        als_attr->val2, &val);
                break;
        case LM3533_ATTR_TYPE_THRESH_FALLING:
                ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
                                                                false, &val);
                break;
        case LM3533_ATTR_TYPE_THRESH_RAISING:
                ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
                                                                true, &val);
                break;
        default:
                ret = -ENXIO;
        }

        if (ret)
                return ret;

        return sysfs_emit(buf, "%u\n", val);
}

static ssize_t store_als_attr(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
        u8 val;
        int ret;

        if (kstrtou8(buf, 0, &val))
                return -EINVAL;

        switch (als_attr->type) {
        case LM3533_ATTR_TYPE_TARGET:
                ret = lm3533_als_set_target(indio_dev, als_attr->val1,
                                                        als_attr->val2, val);
                break;
        case LM3533_ATTR_TYPE_THRESH_FALLING:
                ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
                                                                false, val);
                break;
        case LM3533_ATTR_TYPE_THRESH_RAISING:
                ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
                                                                true, val);
                break;
        default:
                ret = -ENXIO;
        }

        if (ret)
                return ret;

        return len;
}

#define ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)      \
        { .dev_attr     = __ATTR(_name, _mode, _show, _store),          \
          .type         = _type,                                        \
          .val1         = _val1,                                        \
          .val2         = _val2 }

#define LM3533_ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2) \
        struct lm3533_als_attribute lm3533_als_attr_##_name =             \
                ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)

#define ALS_TARGET_ATTR_RW(_channel, _zone)                             \
        LM3533_ALS_ATTR(out_current##_channel##_current##_zone##_raw,   \
                                S_IRUGO | S_IWUSR,                      \
                                show_als_attr, store_als_attr,          \
                                LM3533_ATTR_TYPE_TARGET, _channel, _zone)
/*
 * ALS output current values (ALS mapper targets)
 *
 * out_current[0-2]_current[0-4]_raw            0-255
 */
static ALS_TARGET_ATTR_RW(0, 0);
static ALS_TARGET_ATTR_RW(0, 1);
static ALS_TARGET_ATTR_RW(0, 2);
static ALS_TARGET_ATTR_RW(0, 3);
static ALS_TARGET_ATTR_RW(0, 4);

static ALS_TARGET_ATTR_RW(1, 0);
static ALS_TARGET_ATTR_RW(1, 1);
static ALS_TARGET_ATTR_RW(1, 2);
static ALS_TARGET_ATTR_RW(1, 3);
static ALS_TARGET_ATTR_RW(1, 4);

static ALS_TARGET_ATTR_RW(2, 0);
static ALS_TARGET_ATTR_RW(2, 1);
static ALS_TARGET_ATTR_RW(2, 2);
static ALS_TARGET_ATTR_RW(2, 3);
static ALS_TARGET_ATTR_RW(2, 4);

#define ALS_THRESH_FALLING_ATTR_RW(_nr)                                 \
        LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_falling_value,    \
                        S_IRUGO | S_IWUSR,                              \
                        show_als_attr, store_als_attr,          \
                        LM3533_ATTR_TYPE_THRESH_FALLING, _nr, 0)

#define ALS_THRESH_RAISING_ATTR_RW(_nr)                                 \
        LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_raising_value,    \
                        S_IRUGO | S_IWUSR,                              \
                        show_als_attr, store_als_attr,                  \
                        LM3533_ATTR_TYPE_THRESH_RAISING, _nr, 0)
/*
 * ALS Zone thresholds (boundaries)
 *
 * in_illuminance0_thresh[0-3]_falling_value    0-255
 * in_illuminance0_thresh[0-3]_raising_value    0-255
 */
static ALS_THRESH_FALLING_ATTR_RW(0);
static ALS_THRESH_FALLING_ATTR_RW(1);
static ALS_THRESH_FALLING_ATTR_RW(2);
static ALS_THRESH_FALLING_ATTR_RW(3);

static ALS_THRESH_RAISING_ATTR_RW(0);
static ALS_THRESH_RAISING_ATTR_RW(1);
static ALS_THRESH_RAISING_ATTR_RW(2);
static ALS_THRESH_RAISING_ATTR_RW(3);

#define ALS_HYSTERESIS_ATTR_RO(_nr)                                     \
        LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_hysteresis,       \
                        S_IRUGO, show_als_attr, NULL,                   \
                        LM3533_ATTR_TYPE_HYSTERESIS, _nr, 0)
/*
 * ALS Zone threshold hysteresis
 *
 * threshY_hysteresis = threshY_raising - threshY_falling
 *
 * in_illuminance0_thresh[0-3]_hysteresis       0-255
 * in_illuminance0_thresh[0-3]_hysteresis       0-255
 */
static ALS_HYSTERESIS_ATTR_RO(0);
static ALS_HYSTERESIS_ATTR_RO(1);
static ALS_HYSTERESIS_ATTR_RO(2);
static ALS_HYSTERESIS_ATTR_RO(3);

#define ILLUMINANCE_ATTR_RO(_name) \
        DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO, show_##_name, NULL)
#define ILLUMINANCE_ATTR_RW(_name) \
        DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO | S_IWUSR, \
                                                show_##_name, store_##_name)
/*
 * ALS Zone threshold-event enable
 *
 * in_illuminance0_thresh_either_en             0,1
 */
static ILLUMINANCE_ATTR_RW(thresh_either_en);

/*
 * ALS Current Zone
 *
 * in_illuminance0_zone         0-4
 */
static ILLUMINANCE_ATTR_RO(zone);

static struct attribute *lm3533_als_event_attributes[] = {
        &dev_attr_in_illuminance0_thresh_either_en.attr,
        &lm3533_als_attr_in_illuminance0_thresh0_falling_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh0_hysteresis.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh0_raising_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh1_falling_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh1_hysteresis.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh1_raising_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh2_falling_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh2_hysteresis.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh2_raising_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh3_falling_value.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh3_hysteresis.dev_attr.attr,
        &lm3533_als_attr_in_illuminance0_thresh3_raising_value.dev_attr.attr,
        NULL
};

static const struct attribute_group lm3533_als_event_attribute_group = {
        .attrs = lm3533_als_event_attributes
};

static struct attribute *lm3533_als_attributes[] = {
        &dev_attr_in_illuminance0_zone.attr,
        &lm3533_als_attr_out_current0_current0_raw.dev_attr.attr,
        &lm3533_als_attr_out_current0_current1_raw.dev_attr.attr,
        &lm3533_als_attr_out_current0_current2_raw.dev_attr.attr,
        &lm3533_als_attr_out_current0_current3_raw.dev_attr.attr,
        &lm3533_als_attr_out_current0_current4_raw.dev_attr.attr,
        &lm3533_als_attr_out_current1_current0_raw.dev_attr.attr,
        &lm3533_als_attr_out_current1_current1_raw.dev_attr.attr,
        &lm3533_als_attr_out_current1_current2_raw.dev_attr.attr,
        &lm3533_als_attr_out_current1_current3_raw.dev_attr.attr,
        &lm3533_als_attr_out_current1_current4_raw.dev_attr.attr,
        &lm3533_als_attr_out_current2_current0_raw.dev_attr.attr,
        &lm3533_als_attr_out_current2_current1_raw.dev_attr.attr,
        &lm3533_als_attr_out_current2_current2_raw.dev_attr.attr,
        &lm3533_als_attr_out_current2_current3_raw.dev_attr.attr,
        &lm3533_als_attr_out_current2_current4_raw.dev_attr.attr,
        NULL
};

static const struct attribute_group lm3533_als_attribute_group = {
        .attrs = lm3533_als_attributes
};

static int lm3533_als_set_input_mode(struct lm3533_als *als, bool pwm_mode)
{
        u8 mask = LM3533_ALS_INPUT_MODE_MASK;
        u8 val;
        int ret;

        if (pwm_mode)
                val = mask;     /* pwm input */
        else
                val = 0;        /* analog input */

        ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, val, mask);
        if (ret) {
                dev_err(&als->pdev->dev, "failed to set input mode %d\n",
                                                                pwm_mode);
                return ret;
        }

        return 0;
}

static int lm3533_als_set_resistor(struct lm3533_als *als, u8 val)
{
        int ret;

        if (val < LM3533_ALS_RESISTOR_MIN || val > LM3533_ALS_RESISTOR_MAX) {
                dev_err(&als->pdev->dev, "invalid resistor value\n");
                return -EINVAL;
        }

        ret = lm3533_write(als->lm3533, LM3533_REG_ALS_RESISTOR_SELECT, val);
        if (ret) {
                dev_err(&als->pdev->dev, "failed to set resistor\n");
                return ret;
        }

        return 0;
}

static int lm3533_als_setup(struct lm3533_als *als,
                            const struct lm3533_als_platform_data *pdata)
{
        int ret;

        ret = lm3533_als_set_input_mode(als, pdata->pwm_mode);
        if (ret)
                return ret;

        /* ALS input is always high impedance in PWM-mode. */
        if (!pdata->pwm_mode) {
                ret = lm3533_als_set_resistor(als, pdata->r_select);
                if (ret)
                        return ret;
        }

        return 0;
}

static int lm3533_als_setup_irq(struct lm3533_als *als, void *dev)
{
        u8 mask = LM3533_ALS_INT_ENABLE_MASK;
        int ret;

        /* Make sure interrupts are disabled. */
        ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, 0, mask);
        if (ret) {
                dev_err(&als->pdev->dev, "failed to disable interrupts\n");
                return ret;
        }

        ret = request_threaded_irq(als->irq, NULL, lm3533_als_isr,
                                        IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                                        dev_name(&als->pdev->dev), dev);
        if (ret) {
                dev_err(&als->pdev->dev, "failed to request irq %d\n",
                                                                als->irq);
                return ret;
        }

        return 0;
}

static int lm3533_als_enable(struct lm3533_als *als)
{
        u8 mask = LM3533_ALS_ENABLE_MASK;
        int ret;

        ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, mask, mask);
        if (ret)
                dev_err(&als->pdev->dev, "failed to enable ALS\n");

        return ret;
}

static int lm3533_als_disable(struct lm3533_als *als)
{
        u8 mask = LM3533_ALS_ENABLE_MASK;
        int ret;

        ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, 0, mask);
        if (ret)
                dev_err(&als->pdev->dev, "failed to disable ALS\n");

        return ret;
}

static const struct iio_info lm3533_als_info = {
        .attrs          = &lm3533_als_attribute_group,
        .event_attrs    = &lm3533_als_event_attribute_group,
        .read_raw       = &lm3533_als_read_raw,
};

static int lm3533_als_probe(struct platform_device *pdev)
{
        const struct lm3533_als_platform_data *pdata;
        struct lm3533 *lm3533;
        struct lm3533_als *als;
        struct iio_dev *indio_dev;
        int ret;

        lm3533 = dev_get_drvdata(pdev->dev.parent);
        if (!lm3533)
                return -EINVAL;

        pdata = dev_get_platdata(&pdev->dev);
        if (!pdata) {
                dev_err(&pdev->dev, "no platform data\n");
                return -EINVAL;
        }

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

        indio_dev->info = &lm3533_als_info;
        indio_dev->channels = lm3533_als_channels;
        indio_dev->num_channels = ARRAY_SIZE(lm3533_als_channels);
        indio_dev->name = dev_name(&pdev->dev);
        iio_device_set_parent(indio_dev, pdev->dev.parent);
        indio_dev->modes = INDIO_DIRECT_MODE;

        als = iio_priv(indio_dev);
        als->lm3533 = lm3533;
        als->pdev = pdev;
        als->irq = lm3533->irq;
        atomic_set(&als->zone, 0);
        mutex_init(&als->thresh_mutex);

        platform_set_drvdata(pdev, indio_dev);

        if (als->irq) {
                ret = lm3533_als_setup_irq(als, indio_dev);
                if (ret)
                        return ret;
        }

        ret = lm3533_als_setup(als, pdata);
        if (ret)
                goto err_free_irq;

        ret = lm3533_als_enable(als);
        if (ret)
                goto err_free_irq;

        ret = iio_device_register(indio_dev);
        if (ret) {
                dev_err(&pdev->dev, "failed to register ALS\n");
                goto err_disable;
        }

        return 0;

err_disable:
        lm3533_als_disable(als);
err_free_irq:
        if (als->irq)
                free_irq(als->irq, indio_dev);

        return ret;
}

static void lm3533_als_remove(struct platform_device *pdev)
{
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
        struct lm3533_als *als = iio_priv(indio_dev);

        lm3533_als_set_int_mode(indio_dev, false);
        iio_device_unregister(indio_dev);
        lm3533_als_disable(als);
        if (als->irq)
                free_irq(als->irq, indio_dev);
}

static struct platform_driver lm3533_als_driver = {
        .driver = {
                .name   = "lm3533-als",
        },
        .probe          = lm3533_als_probe,
        .remove         = lm3533_als_remove,
};
module_platform_driver(lm3533_als_driver);

MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
MODULE_DESCRIPTION("LM3533 Ambient Light Sensor driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lm3533-als");