hid-sensor-als.c

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/*
 * HID Sensors Driver
 * Copyright (c) 2012, Intel Corporation.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/hid-sensor-hub.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include "../common/hid-sensors/hid-sensor-attributes.h"
#include "../common/hid-sensors/hid-sensor-trigger.h"

/*Format: HID-SENSOR-usage_id_in_hex*/
/*Usage ID from spec for Accelerometer-3D: 0x200041*/
#define DRIVER_NAME "HID-SENSOR-200041"

#define CHANNEL_SCAN_INDEX_ILLUM 0

struct als_state {
    struct hid_sensor_hub_callbacks callbacks;
    struct hid_sensor_iio_common common_attributes;
    struct hid_sensor_hub_attribute_info als_illum;
    u32 illum;
};

/* Channel definitions */
static const struct iio_chan_spec als_channels[] = {
    {
        .type = IIO_INTENSITY,
        .modified = 1,
        .channel2 = IIO_MOD_LIGHT_BOTH,
        .info_mask = IIO_CHAN_INFO_OFFSET_SHARED_BIT |
        IIO_CHAN_INFO_SCALE_SHARED_BIT |
        IIO_CHAN_INFO_SAMP_FREQ_SHARED_BIT |
        IIO_CHAN_INFO_HYSTERESIS_SHARED_BIT,
        .scan_index = CHANNEL_SCAN_INDEX_ILLUM,
    }
};

/* Adjust channel real bits based on report descriptor */
static void als_adjust_channel_bit_mask(struct iio_chan_spec *channels,
                    int channel, int size)
{
    channels[channel].scan_type.sign = 's';
    /* Real storage bits will change based on the report desc. */
    channels[channel].scan_type.realbits = size * 8;
    /* Maximum size of a sample to capture is u32 */
    channels[channel].scan_type.storagebits = sizeof(u32) * 8;
}

/* Channel read_raw handler */
static int als_read_raw(struct iio_dev *indio_dev,
                  struct iio_chan_spec const *chan,
                  int *val, int *val2,
                  long mask)
{
    struct als_state *als_state = iio_priv(indio_dev);
    int report_id = -1;
    u32 address;
    int ret;
    int ret_type;

    *val = 0;
    *val2 = 0;
    switch (mask) {
    case 0:
        switch (chan->scan_index) {
        case  CHANNEL_SCAN_INDEX_ILLUM:
            report_id = als_state->als_illum.report_id;
            address =
            HID_USAGE_SENSOR_LIGHT_ILLUM;
            break;
        default:
            report_id = -1;
            break;
        }
        if (report_id >= 0)
            *val = sensor_hub_input_attr_get_raw_value(
                als_state->common_attributes.hsdev,
                HID_USAGE_SENSOR_ALS, address,
                report_id);
        else {
            *val = 0;
            return -EINVAL;
        }
        ret_type = IIO_VAL_INT;
        break;
    case IIO_CHAN_INFO_SCALE:
        *val = als_state->als_illum.units;
        ret_type = IIO_VAL_INT;
        break;
    case IIO_CHAN_INFO_OFFSET:
        *val = hid_sensor_convert_exponent(
                als_state->als_illum.unit_expo);
        ret_type = IIO_VAL_INT;
        break;
    case IIO_CHAN_INFO_SAMP_FREQ:
        ret = hid_sensor_read_samp_freq_value(
                &als_state->common_attributes, val, val2);
        ret_type = IIO_VAL_INT_PLUS_MICRO;
        break;
    case IIO_CHAN_INFO_HYSTERESIS:
        ret = hid_sensor_read_raw_hyst_value(
                &als_state->common_attributes, val, val2);
        ret_type = IIO_VAL_INT_PLUS_MICRO;
        break;
    default:
        ret_type = -EINVAL;
        break;
    }

    return ret_type;
}

/* Channel write_raw handler */
static int als_write_raw(struct iio_dev *indio_dev,
                   struct iio_chan_spec const *chan,
                   int val,
                   int val2,
                   long mask)
{
    struct als_state *als_state = iio_priv(indio_dev);
    int ret = 0;

    switch (mask) {
    case IIO_CHAN_INFO_SAMP_FREQ:
        ret = hid_sensor_write_samp_freq_value(
                &als_state->common_attributes, val, val2);
        break;
    case IIO_CHAN_INFO_HYSTERESIS:
        ret = hid_sensor_write_raw_hyst_value(
                &als_state->common_attributes, val, val2);
        break;
    default:
        ret = -EINVAL;
    }

    return ret;
}

static int als_write_raw_get_fmt(struct iio_dev *indio_dev,
                   struct iio_chan_spec const *chan,
                   long mask)
{
    return IIO_VAL_INT_PLUS_MICRO;
}

static const struct iio_info als_info = {
    .driver_module = THIS_MODULE,
    .read_raw = &als_read_raw,
    .write_raw = &als_write_raw,
    .write_raw_get_fmt = &als_write_raw_get_fmt,
};

/* Function to push data to buffer */
static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
{
    struct iio_buffer *buffer = indio_dev->buffer;
    int datum_sz;

    dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
    if (!buffer) {
        dev_err(&indio_dev->dev, "Buffer == NULL\n");
        return;
    }
    datum_sz = buffer->access->get_bytes_per_datum(buffer);
    if (len > datum_sz) {
        dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
                datum_sz);
        return;
    }
    iio_push_to_buffer(buffer, (u8 *)data);
}

/* Callback handler to send event after all samples are received and captured */
static int als_proc_event(struct hid_sensor_hub_device *hsdev,
                unsigned usage_id,
                void *priv)
{
    struct iio_dev *indio_dev = platform_get_drvdata(priv);
    struct als_state *als_state = iio_priv(indio_dev);

    dev_dbg(&indio_dev->dev, "als_proc_event [%d]\n",
                als_state->common_attributes.data_ready);
    if (als_state->common_attributes.data_ready)
        hid_sensor_push_data(indio_dev,
                (u8 *)&als_state->illum,
                sizeof(als_state->illum));

    return 0;
}

/* Capture samples in local storage */
static int als_capture_sample(struct hid_sensor_hub_device *hsdev,
                unsigned usage_id,
                size_t raw_len, char *raw_data,
                void *priv)
{
    struct iio_dev *indio_dev = platform_get_drvdata(priv);
    struct als_state *als_state = iio_priv(indio_dev);
    int ret = -EINVAL;

    switch (usage_id) {
    case HID_USAGE_SENSOR_LIGHT_ILLUM:
        als_state->illum = *(u32 *)raw_data;
        ret = 0;
        break;
    default:
        break;
    }

    return ret;
}

/* Parse report which is specific to an usage id*/
static int als_parse_report(struct platform_device *pdev,
                struct hid_sensor_hub_device *hsdev,
                struct iio_chan_spec *channels,
                unsigned usage_id,
                struct als_state *st)
{
    int ret;

    ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
            usage_id,
            HID_USAGE_SENSOR_LIGHT_ILLUM,
            &st->als_illum);
    if (ret < 0)
        return ret;
    als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_ILLUM,
                    st->als_illum.size);

    dev_dbg(&pdev->dev, "als %x:%x\n", st->als_illum.index,
            st->als_illum.report_id);

    return ret;
}

/* Function to initialize the processing for usage id */
static int __devinit hid_als_probe(struct platform_device *pdev)
{
    int ret = 0;
    static const char *name = "als";
    struct iio_dev *indio_dev;
    struct als_state *als_state;
    struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
    struct iio_chan_spec *channels;

    indio_dev = iio_device_alloc(sizeof(struct als_state));
    if (indio_dev == NULL) {
        ret = -ENOMEM;
        goto error_ret;
    }
    platform_set_drvdata(pdev, indio_dev);

    als_state = iio_priv(indio_dev);
    als_state->common_attributes.hsdev = hsdev;
    als_state->common_attributes.pdev = pdev;

    ret = hid_sensor_parse_common_attributes(hsdev, HID_USAGE_SENSOR_ALS,
                    &als_state->common_attributes);
    if (ret) {
        dev_err(&pdev->dev, "failed to setup common attributes\n");
        goto error_free_dev;
    }

    channels = kmemdup(als_channels,
                    sizeof(als_channels),
                    GFP_KERNEL);
    if (!channels) {
        dev_err(&pdev->dev, "failed to duplicate channels\n");
        goto error_free_dev;
    }

    ret = als_parse_report(pdev, hsdev, channels,
                HID_USAGE_SENSOR_ALS, als_state);
    if (ret) {
        dev_err(&pdev->dev, "failed to setup attributes\n");
        goto error_free_dev_mem;
    }

    indio_dev->channels = channels;
    indio_dev->num_channels =
                ARRAY_SIZE(als_channels);
    indio_dev->dev.parent = &pdev->dev;
    indio_dev->info = &als_info;
    indio_dev->name = name;
    indio_dev->modes = INDIO_DIRECT_MODE;

    ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
        NULL, NULL);
    if (ret) {
        dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
        goto error_free_dev_mem;
    }
    als_state->common_attributes.data_ready = false;
    ret = hid_sensor_setup_trigger(indio_dev, name,
                &als_state->common_attributes);
    if (ret < 0) {
        dev_err(&pdev->dev, "trigger setup failed\n");
        goto error_unreg_buffer_funcs;
    }

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

    als_state->callbacks.send_event = als_proc_event;
    als_state->callbacks.capture_sample = als_capture_sample;
    als_state->callbacks.pdev = pdev;
    ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_ALS,
                    &als_state->callbacks);
    if (ret < 0) {
        dev_err(&pdev->dev, "callback reg failed\n");
        goto error_iio_unreg;
    }

    return ret;

error_iio_unreg:
    iio_device_unregister(indio_dev);
error_remove_trigger:
    hid_sensor_remove_trigger(indio_dev);
error_unreg_buffer_funcs:
    iio_triggered_buffer_cleanup(indio_dev);
error_free_dev_mem:
    kfree(indio_dev->channels);
error_free_dev:
    iio_device_free(indio_dev);
error_ret:
    return ret;
}

/* Function to deinitialize the processing for usage id */
static int __devinit hid_als_remove(struct platform_device *pdev)
{
    struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
    struct iio_dev *indio_dev = platform_get_drvdata(pdev);

    sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_ALS);
    iio_device_unregister(indio_dev);
    hid_sensor_remove_trigger(indio_dev);
    iio_triggered_buffer_cleanup(indio_dev);
    kfree(indio_dev->channels);
    iio_device_free(indio_dev);

    return 0;
}

static struct platform_driver hid_als_platform_driver = {
    .driver = {
        .name   = DRIVER_NAME,
        .owner  = THIS_MODULE,
    },
    .probe      = hid_als_probe,
    .remove     = hid_als_remove,
};
module_platform_driver(hid_als_platform_driver);

MODULE_DESCRIPTION("HID Sensor ALS");
MODULE_AUTHOR("Srinivas Pandruvada <[email protected]>");
MODULE_LICENSE("GPL");