isl29028.c

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/*
 * IIO driver for the light sensor ISL29028.
 * ISL29028 is Concurrent Ambient Light and Proximity Sensor
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define CONVERSION_TIME_MS      100

#define ISL29028_REG_CONFIGURE      0x01

#define CONFIGURE_ALS_IR_MODE_ALS   0
#define CONFIGURE_ALS_IR_MODE_IR    BIT(0)
#define CONFIGURE_ALS_IR_MODE_MASK  BIT(0)

#define CONFIGURE_ALS_RANGE_LOW_LUX 0
#define CONFIGURE_ALS_RANGE_HIGH_LUX    BIT(1)
#define CONFIGURE_ALS_RANGE_MASK    BIT(1)

#define CONFIGURE_ALS_DIS       0
#define CONFIGURE_ALS_EN        BIT(2)
#define CONFIGURE_ALS_EN_MASK       BIT(2)

#define CONFIGURE_PROX_DRIVE        BIT(3)

#define CONFIGURE_PROX_SLP_SH       4
#define CONFIGURE_PROX_SLP_MASK     (7 << CONFIGURE_PROX_SLP_SH)

#define CONFIGURE_PROX_EN       BIT(7)
#define CONFIGURE_PROX_EN_MASK      BIT(7)

#define ISL29028_REG_INTERRUPT      0x02

#define ISL29028_REG_PROX_DATA      0x08
#define ISL29028_REG_ALSIR_L        0x09
#define ISL29028_REG_ALSIR_U        0x0A

#define ISL29028_REG_TEST1_MODE     0x0E
#define ISL29028_REG_TEST2_MODE     0x0F

#define ISL29028_NUM_REGS       (ISL29028_REG_TEST2_MODE + 1)

enum als_ir_mode {
    MODE_NONE = 0,
    MODE_ALS,
    MODE_IR
};

struct isl29028_chip {
    struct device       *dev;
    struct mutex        lock;
    struct regmap       *regmap;

    unsigned int        prox_sampling;
    bool            enable_prox;

    int         lux_scale;
    int         als_ir_mode;
};

static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
            unsigned int sampling)
{
    static unsigned int prox_period[] = {800, 400, 200, 100, 75, 50, 12, 0};
    int sel;
    unsigned int period = DIV_ROUND_UP(1000, sampling);

    for (sel = 0; sel < ARRAY_SIZE(prox_period); ++sel) {
        if (period >= prox_period[sel])
            break;
    }
    return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_PROX_SLP_MASK, sel << CONFIGURE_PROX_SLP_SH);
}

static int isl29028_enable_proximity(struct isl29028_chip *chip, bool enable)
{
    int ret;
    int val = 0;

    if (enable)
        val = CONFIGURE_PROX_EN;
    ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_PROX_EN_MASK, val);
    if (ret < 0)
        return ret;

    /* Wait for conversion to be complete for first sample */
    mdelay(DIV_ROUND_UP(1000, chip->prox_sampling));
    return 0;
}

static int isl29028_set_als_scale(struct isl29028_chip *chip, int lux_scale)
{
    int val = (lux_scale == 2000) ? CONFIGURE_ALS_RANGE_HIGH_LUX :
                    CONFIGURE_ALS_RANGE_LOW_LUX;

    return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
        CONFIGURE_ALS_RANGE_MASK, val);
}

static int isl29028_set_als_ir_mode(struct isl29028_chip *chip,
    enum als_ir_mode mode)
{
    int ret = 0;

    switch (mode) {
    case MODE_ALS:
        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_ALS);
        if (ret < 0)
            return ret;

        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_ALS_RANGE_MASK, CONFIGURE_ALS_RANGE_HIGH_LUX);
        break;

    case MODE_IR:
        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_IR);
        break;

    case MODE_NONE:
        return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_DIS);
    }

    if (ret < 0)
        return ret;

    /* Enable the ALS/IR */
    ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
            CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_EN);
    if (ret < 0)
        return ret;

    /* Need to wait for conversion time if ALS/IR mode enabled */
    mdelay(CONVERSION_TIME_MS);
    return 0;
}

static int isl29028_read_als_ir(struct isl29028_chip *chip, int *als_ir)
{
    unsigned int lsb;
    unsigned int msb;
    int ret;

    ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_L, &lsb);
    if (ret < 0) {
        dev_err(chip->dev,
            "Error in reading register ALSIR_L err %d\n", ret);
        return ret;
    }

    ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_U, &msb);
    if (ret < 0) {
        dev_err(chip->dev,
            "Error in reading register ALSIR_U err %d\n", ret);
        return ret;
    }

    *als_ir = ((msb & 0xF) << 8) | (lsb & 0xFF);
    return 0;
}

static int isl29028_read_proxim(struct isl29028_chip *chip, int *prox)
{
    unsigned int data;
    int ret;

    ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
    if (ret < 0) {
        dev_err(chip->dev, "Error in reading register %d, error %d\n",
                ISL29028_REG_PROX_DATA, ret);
        return ret;
    }
    *prox = data;
    return 0;
}

static int isl29028_proxim_get(struct isl29028_chip *chip, int *prox_data)
{
    int ret;

    if (!chip->enable_prox) {
        ret = isl29028_enable_proximity(chip, true);
        if (ret < 0)
            return ret;
        chip->enable_prox = true;
    }
    return isl29028_read_proxim(chip, prox_data);
}

static int isl29028_als_get(struct isl29028_chip *chip, int *als_data)
{
    int ret;
    int als_ir_data;

    if (chip->als_ir_mode != MODE_ALS) {
        ret = isl29028_set_als_ir_mode(chip, MODE_ALS);
        if (ret < 0) {
            dev_err(chip->dev,
                "Error in enabling ALS mode err %d\n", ret);
            return ret;
        }
        chip->als_ir_mode = MODE_ALS;
    }

    ret = isl29028_read_als_ir(chip, &als_ir_data);
    if (ret < 0)
        return ret;

    /*
     * convert als data count to lux.
     * if lux_scale = 125,  lux = count * 0.031
     * if lux_scale = 2000, lux = count * 0.49
     */
    if (chip->lux_scale == 125)
        als_ir_data = (als_ir_data * 31) / 1000;
    else
        als_ir_data = (als_ir_data * 49) / 100;

    *als_data = als_ir_data;
    return 0;
}

static int isl29028_ir_get(struct isl29028_chip *chip, int *ir_data)
{
    int ret;

    if (chip->als_ir_mode != MODE_IR) {
        ret = isl29028_set_als_ir_mode(chip, MODE_IR);
        if (ret < 0) {
            dev_err(chip->dev,
                "Error in enabling IR mode err %d\n", ret);
            return ret;
        }
        chip->als_ir_mode = MODE_IR;
    }
    return isl29028_read_als_ir(chip, ir_data);
}

/* Channel IO */
static int isl29028_write_raw(struct iio_dev *indio_dev,
         struct iio_chan_spec const *chan, int val, int val2, long mask)
{
    struct isl29028_chip *chip = iio_priv(indio_dev);
    int ret = -EINVAL;

    mutex_lock(&chip->lock);
    switch (chan->type) {
    case IIO_PROXIMITY:
        if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
            dev_err(chip->dev,
                "proximity: mask value 0x%08lx not supported\n",
                mask);
            break;
        }
        if (val < 1 || val > 100) {
            dev_err(chip->dev,
                "Samp_freq %d is not in range[1:100]\n", val);
            break;
        }
        ret = isl29028_set_proxim_sampling(chip, val);
        if (ret < 0) {
            dev_err(chip->dev,
                "Setting proximity samp_freq fail, err %d\n",
                ret);
            break;
        }
        chip->prox_sampling = val;
        break;

    case IIO_LIGHT:
        if (mask != IIO_CHAN_INFO_SCALE) {
            dev_err(chip->dev,
                "light: mask value 0x%08lx not supported\n",
                mask);
            break;
        }
        if ((val != 125) && (val != 2000)) {
            dev_err(chip->dev,
                "lux scale %d is invalid [125, 2000]\n", val);
            break;
        }
        ret = isl29028_set_als_scale(chip, val);
        if (ret < 0) {
            dev_err(chip->dev,
                "Setting lux scale fail with error %d\n", ret);
            break;
        }
        chip->lux_scale = val;
        break;

    default:
        dev_err(chip->dev, "Unsupported channel type\n");
        break;
    }
    mutex_unlock(&chip->lock);
    return ret;
}

static int isl29028_read_raw(struct iio_dev *indio_dev,
         struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
    struct isl29028_chip *chip = iio_priv(indio_dev);
    int ret = -EINVAL;

    mutex_lock(&chip->lock);
    switch (mask) {
    case IIO_CHAN_INFO_RAW:
    case IIO_CHAN_INFO_PROCESSED:
        switch (chan->type) {
        case IIO_LIGHT:
            ret = isl29028_als_get(chip, val);
            break;
        case IIO_INTENSITY:
            ret = isl29028_ir_get(chip, val);
            break;
        case IIO_PROXIMITY:
            ret = isl29028_proxim_get(chip, val);
            break;
        default:
            break;
        }
        if (ret < 0)
            break;
        ret = IIO_VAL_INT;
        break;

    case IIO_CHAN_INFO_SAMP_FREQ:
        if (chan->type != IIO_PROXIMITY)
            break;
        *val = chip->prox_sampling;
        ret = IIO_VAL_INT;
        break;

    case IIO_CHAN_INFO_SCALE:
        if (chan->type != IIO_LIGHT)
            break;
        *val = chip->lux_scale;
        ret = IIO_VAL_INT;
        break;

    default:
        dev_err(chip->dev, "mask value 0x%08lx not supported\n", mask);
        break;
    }
    mutex_unlock(&chip->lock);
    return ret;
}

static IIO_CONST_ATTR(in_proximity_sampling_frequency_available,
                "1, 3, 5, 10, 13, 20, 83, 100");
static IIO_CONST_ATTR(in_illuminance_scale_available, "125, 2000");

#define ISL29028_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
#define ISL29028_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
static struct attribute *isl29028_attributes[] = {
    ISL29028_CONST_ATTR(in_proximity_sampling_frequency_available),
    ISL29028_CONST_ATTR(in_illuminance_scale_available),
    NULL,
};

static const struct attribute_group isl29108_group = {
    .attrs = isl29028_attributes,
};

static const struct iio_chan_spec isl29028_channels[] = {
    {
        .type = IIO_LIGHT,
        .info_mask = IIO_CHAN_INFO_PROCESSED_SEPARATE_BIT |
        IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
    }, {
        .type = IIO_INTENSITY,
        .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
    }, {
        .type = IIO_PROXIMITY,
        .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
        IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT,
    }
};

static const struct iio_info isl29028_info = {
    .attrs = &isl29108_group,
    .driver_module = THIS_MODULE,
    .read_raw = &isl29028_read_raw,
    .write_raw = &isl29028_write_raw,
};

static int isl29028_chip_init(struct isl29028_chip *chip)
{
    int ret;

    chip->enable_prox  = false;
    chip->prox_sampling = 20;
    chip->lux_scale = 2000;
    chip->als_ir_mode = MODE_NONE;

    ret = regmap_write(chip->regmap, ISL29028_REG_TEST1_MODE, 0x0);
    if (ret < 0) {
        dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
            __func__, ISL29028_REG_TEST1_MODE, ret);
        return ret;
    }
    ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
    if (ret < 0) {
        dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
            __func__, ISL29028_REG_TEST2_MODE, ret);
        return ret;
    }

    ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
    if (ret < 0) {
        dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
            __func__, ISL29028_REG_CONFIGURE, ret);
        return ret;
    }

    ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling);
    if (ret < 0) {
        dev_err(chip->dev, "%s(): setting the proximity, err = %d\n",
            __func__, ret);
        return ret;
    }

    ret = isl29028_set_als_scale(chip, chip->lux_scale);
    if (ret < 0)
        dev_err(chip->dev, "%s(): setting als scale failed, err = %d\n",
            __func__, ret);
    return ret;
}

static bool is_volatile_reg(struct device *dev, unsigned int reg)
{
    switch (reg) {
    case ISL29028_REG_INTERRUPT:
    case ISL29028_REG_PROX_DATA:
    case ISL29028_REG_ALSIR_L:
    case ISL29028_REG_ALSIR_U:
        return true;
    default:
        return false;
    }
}

static const struct regmap_config isl29028_regmap_config = {
    .reg_bits = 8,
    .val_bits = 8,
    .volatile_reg = is_volatile_reg,
    .max_register = ISL29028_NUM_REGS - 1,
    .num_reg_defaults_raw = ISL29028_NUM_REGS,
    .cache_type = REGCACHE_RBTREE,
};

static int __devinit isl29028_probe(struct i2c_client *client,
    const struct i2c_device_id *id)
{
    struct isl29028_chip *chip;
    struct iio_dev *indio_dev;
    int ret;

    indio_dev = iio_device_alloc(sizeof(*chip));
    if (!indio_dev) {
        dev_err(&client->dev, "iio allocation fails\n");
        return -ENOMEM;
    }

    chip = iio_priv(indio_dev);

    i2c_set_clientdata(client, indio_dev);
    chip->dev = &client->dev;
    mutex_init(&chip->lock);

    chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
    if (IS_ERR(chip->regmap)) {
        ret = PTR_ERR(chip->regmap);
        dev_err(chip->dev, "regmap initialization failed: %d\n", ret);
        goto exit_iio_free;
    }

    ret = isl29028_chip_init(chip);
    if (ret < 0) {
        dev_err(chip->dev, "chip initialization failed: %d\n", ret);
        goto exit_iio_free;
    }

    indio_dev->info = &isl29028_info;
    indio_dev->channels = isl29028_channels;
    indio_dev->num_channels = ARRAY_SIZE(isl29028_channels);
    indio_dev->name = id->name;
    indio_dev->dev.parent = &client->dev;
    indio_dev->modes = INDIO_DIRECT_MODE;
    ret = iio_device_register(indio_dev);
    if (ret < 0) {
        dev_err(chip->dev, "iio registration fails with error %d\n",
            ret);
        goto exit_iio_free;
    }
    return 0;

exit_iio_free:
    iio_device_free(indio_dev);
    return ret;
}

static int __devexit isl29028_remove(struct i2c_client *client)
{
    struct iio_dev *indio_dev = i2c_get_clientdata(client);

    iio_device_unregister(indio_dev);
    iio_device_free(indio_dev);
    return 0;
}

static const struct i2c_device_id isl29028_id[] = {
    {"isl29028", 0},
    {}
};
MODULE_DEVICE_TABLE(i2c, isl29028_id);

static const struct of_device_id isl29028_of_match[] = {
    { .compatible = "isil,isl29028", },
    { },
};
MODULE_DEVICE_TABLE(of, isl29028_of_match);

static struct i2c_driver isl29028_driver = {
    .class  = I2C_CLASS_HWMON,
    .driver  = {
        .name = "isl29028",
        .owner = THIS_MODULE,
        .of_match_table = isl29028_of_match,
    },
    .probe   = isl29028_probe,
    .remove  = __devexit_p(isl29028_remove),
    .id_table = isl29028_id,
};

module_i2c_driver(isl29028_driver);

MODULE_DESCRIPTION("ISL29028 Ambient Light and Proximity Sensor driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Laxman Dewangan <[email protected]>");