adjd_s311.c

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/*
 * adjd_s311.c - Support for ADJD-S311-CR999 digital color sensor
 *
 * Copyright (C) 2012 Peter Meerwald <[email protected]>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * driver for ADJD-S311-CR999 digital color sensor (10-bit channels for
 * red, green, blue, clear); 7-bit I2C slave address 0x74
 *
 * limitations: no calibration, no offset mode, no sleep mode
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/bitmap.h>
#include <linux/err.h>
#include <linux/irq.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 ADJD_S311_DRV_NAME "adjd_s311"

#define ADJD_S311_CTRL      0x00
#define ADJD_S311_CONFIG    0x01
#define ADJD_S311_CAP_RED   0x06
#define ADJD_S311_CAP_GREEN 0x07
#define ADJD_S311_CAP_BLUE  0x08
#define ADJD_S311_CAP_CLEAR 0x09
#define ADJD_S311_INT_RED_LO    0x0a
#define ADJD_S311_INT_RED_HI    0x0b
#define ADJD_S311_INT_GREEN_LO  0x0c
#define ADJD_S311_INT_GREEN_HI  0x0d
#define ADJD_S311_INT_BLUE_LO   0x0e
#define ADJD_S311_INT_BLUE_HI   0x0f
#define ADJD_S311_INT_CLEAR_LO  0x10
#define ADJD_S311_INT_CLEAR_HI  0x11
#define ADJD_S311_DATA_RED_LO   0x40
#define ADJD_S311_DATA_RED_HI   0x41
#define ADJD_S311_DATA_GREEN_LO 0x42
#define ADJD_S311_DATA_GREEN_HI 0x43
#define ADJD_S311_DATA_BLUE_LO  0x44
#define ADJD_S311_DATA_BLUE_HI  0x45
#define ADJD_S311_DATA_CLEAR_LO 0x46
#define ADJD_S311_DATA_CLEAR_HI 0x47
#define ADJD_S311_OFFSET_RED    0x48
#define ADJD_S311_OFFSET_GREEN  0x49
#define ADJD_S311_OFFSET_BLUE   0x4a
#define ADJD_S311_OFFSET_CLEAR  0x4b

#define ADJD_S311_CTRL_GOFS 0x02
#define ADJD_S311_CTRL_GSSR 0x01
#define ADJD_S311_CAP_MASK  0x0f
#define ADJD_S311_INT_MASK  0x0fff
#define ADJD_S311_DATA_MASK 0x03ff

struct adjd_s311_data {
    struct i2c_client *client;
    u16 *buffer;
};

enum adjd_s311_channel_idx {
    IDX_RED, IDX_GREEN, IDX_BLUE, IDX_CLEAR
};

#define ADJD_S311_DATA_REG(chan) (ADJD_S311_DATA_RED_LO + (chan) * 2)
#define ADJD_S311_INT_REG(chan) (ADJD_S311_INT_RED_LO + (chan) * 2)
#define ADJD_S311_CAP_REG(chan) (ADJD_S311_CAP_RED + (chan))

static int adjd_s311_req_data(struct iio_dev *indio_dev)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);
    int tries = 10;

    int ret = i2c_smbus_write_byte_data(data->client, ADJD_S311_CTRL,
        ADJD_S311_CTRL_GSSR);
    if (ret < 0)
        return ret;

    while (tries--) {
        ret = i2c_smbus_read_byte_data(data->client, ADJD_S311_CTRL);
        if (ret < 0)
            return ret;
        if (!(ret & ADJD_S311_CTRL_GSSR))
            break;
        msleep(20);
    }

    if (tries < 0) {
        dev_err(&data->client->dev,
            "adjd_s311_req_data() failed, data not ready\n");
        return -EIO;
    }

    return 0;
}

static int adjd_s311_read_data(struct iio_dev *indio_dev, u8 reg, int *val)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);

    int ret = adjd_s311_req_data(indio_dev);
    if (ret < 0)
        return ret;

    ret = i2c_smbus_read_word_data(data->client, reg);
    if (ret < 0)
        return ret;

    *val = ret & ADJD_S311_DATA_MASK;

    return 0;
}

static ssize_t adjd_s311_read_int_time(struct iio_dev *indio_dev,
    uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);
    s32 ret;

    ret = i2c_smbus_read_word_data(data->client,
        ADJD_S311_INT_REG(chan->address));
    if (ret < 0)
        return ret;

    return sprintf(buf, "%d\n", ret & ADJD_S311_INT_MASK);
}

static ssize_t adjd_s311_write_int_time(struct iio_dev *indio_dev,
     uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
     size_t len)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);
    unsigned long int_time;
    int ret;

    ret = kstrtoul(buf, 10, &int_time);
    if (ret)
        return ret;

    if (int_time > ADJD_S311_INT_MASK)
        return -EINVAL;

    ret = i2c_smbus_write_word_data(data->client,
        ADJD_S311_INT_REG(chan->address), int_time);
    if (ret < 0)
        return ret;

    return len;
}

static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
{
    struct iio_poll_func *pf = p;
    struct iio_dev *indio_dev = pf->indio_dev;
    struct adjd_s311_data *data = iio_priv(indio_dev);
    struct iio_buffer *buffer = indio_dev->buffer;
    s64 time_ns = iio_get_time_ns();
    int len = 0;
    int i, j = 0;

    int ret = adjd_s311_req_data(indio_dev);
    if (ret < 0)
        goto done;

    for_each_set_bit(i, indio_dev->active_scan_mask,
        indio_dev->masklength) {
        ret = i2c_smbus_read_word_data(data->client,
            ADJD_S311_DATA_REG(i));
        if (ret < 0)
            goto done;

        data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
        len += 2;
    }

    if (indio_dev->scan_timestamp)
        *(s64 *)((u8 *)data->buffer + ALIGN(len, sizeof(s64)))
            = time_ns;
    iio_push_to_buffer(buffer, (u8 *)data->buffer);

done:
    iio_trigger_notify_done(indio_dev->trig);

    return IRQ_HANDLED;
}

static const struct iio_chan_spec_ext_info adjd_s311_ext_info[] = {
    {
        .name = "integration_time",
        .read = adjd_s311_read_int_time,
        .write = adjd_s311_write_int_time,
    },
    { }
};

#define ADJD_S311_CHANNEL(_color, _scan_idx) { \
    .type = IIO_INTENSITY, \
    .modified = 1, \
    .address = (IDX_##_color), \
    .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
        IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT, \
    .channel2 = (IIO_MOD_LIGHT_##_color), \
    .scan_index = (_scan_idx), \
    .scan_type = IIO_ST('u', 10, 16, 0), \
    .ext_info = adjd_s311_ext_info, \
}

static const struct iio_chan_spec adjd_s311_channels[] = {
    ADJD_S311_CHANNEL(RED, 0),
    ADJD_S311_CHANNEL(GREEN, 1),
    ADJD_S311_CHANNEL(BLUE, 2),
    ADJD_S311_CHANNEL(CLEAR, 3),
    IIO_CHAN_SOFT_TIMESTAMP(4),
};

static int adjd_s311_read_raw(struct iio_dev *indio_dev,
               struct iio_chan_spec const *chan,
               int *val, int *val2, long mask)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);
    int ret;

    switch (mask) {
    case IIO_CHAN_INFO_RAW:
        ret = adjd_s311_read_data(indio_dev, chan->address, val);
        if (ret < 0)
            return ret;
        return IIO_VAL_INT;
    case IIO_CHAN_INFO_HARDWAREGAIN:
        ret = i2c_smbus_read_byte_data(data->client,
            ADJD_S311_CAP_REG(chan->address));
        if (ret < 0)
            return ret;
        *val = ret & ADJD_S311_CAP_MASK;
        return IIO_VAL_INT;
    }
    return -EINVAL;
}

static int adjd_s311_write_raw(struct iio_dev *indio_dev,
                   struct iio_chan_spec const *chan,
                   int val, int val2, long mask)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);
    int ret;

    switch (mask) {
    case IIO_CHAN_INFO_HARDWAREGAIN:
        if (val < 0 || val > ADJD_S311_CAP_MASK)
            return -EINVAL;

        ret = i2c_smbus_write_byte_data(data->client,
            ADJD_S311_CAP_REG(chan->address), val);
        return ret;
    }
    return -EINVAL;
}

static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
    const unsigned long *scan_mask)
{
    struct adjd_s311_data *data = iio_priv(indio_dev);

    kfree(data->buffer);
    data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
    if (data->buffer == NULL)
        return -ENOMEM;

    return 0;
}

static const struct iio_info adjd_s311_info = {
    .read_raw = adjd_s311_read_raw,
    .write_raw = adjd_s311_write_raw,
    .update_scan_mode = adjd_s311_update_scan_mode,
    .driver_module = THIS_MODULE,
};

static int __devinit adjd_s311_probe(struct i2c_client *client,
            const struct i2c_device_id *id)
{
    struct adjd_s311_data *data;
    struct iio_dev *indio_dev;
    int err;

    indio_dev = iio_device_alloc(sizeof(*data));
    if (indio_dev == NULL) {
        err = -ENOMEM;
        goto exit;
    }
    data = iio_priv(indio_dev);
    i2c_set_clientdata(client, indio_dev);
    data->client = client;

    indio_dev->dev.parent = &client->dev;
    indio_dev->info = &adjd_s311_info;
    indio_dev->name = ADJD_S311_DRV_NAME;
    indio_dev->channels = adjd_s311_channels;
    indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
    indio_dev->modes = INDIO_DIRECT_MODE;

    err = iio_triggered_buffer_setup(indio_dev, NULL,
        adjd_s311_trigger_handler, NULL);
    if (err < 0)
        goto exit_free_device;

    err = iio_device_register(indio_dev);
    if (err)
        goto exit_unreg_buffer;

    dev_info(&client->dev, "ADJD-S311 color sensor registered\n");

    return 0;

exit_unreg_buffer:
    iio_triggered_buffer_cleanup(indio_dev);
exit_free_device:
    iio_device_free(indio_dev);
exit:
    return err;
}

static int __devexit adjd_s311_remove(struct i2c_client *client)
{
    struct iio_dev *indio_dev = i2c_get_clientdata(client);
    struct adjd_s311_data *data = iio_priv(indio_dev);

    iio_device_unregister(indio_dev);
    iio_triggered_buffer_cleanup(indio_dev);
    kfree(data->buffer);
    iio_device_free(indio_dev);

    return 0;
}

static const struct i2c_device_id adjd_s311_id[] = {
    { "adjd_s311", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, adjd_s311_id);

static struct i2c_driver adjd_s311_driver = {
    .driver = {
        .name   = ADJD_S311_DRV_NAME,
    },
    .probe      = adjd_s311_probe,
    .remove     = __devexit_p(adjd_s311_remove),
    .id_table   = adjd_s311_id,
};
module_i2c_driver(adjd_s311_driver);

MODULE_AUTHOR("Peter Meerwald <[email protected]>");
MODULE_DESCRIPTION("ADJD-S311 color sensor");
MODULE_LICENSE("GPL");