1. 根目录:
2. drivers
3. iio
4. accel
5. ssp_accel_sensor.c

/*
 *  Copyright (C) 2014, Samsung Electronics Co. Ltd. All Rights Reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that 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.
 *
 */

#include <linux/iio/common/ssp_sensors.h>
#include <linux/iio/iio.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "../common/ssp_sensors/ssp_iio_sensor.h"

#define SSP_CHANNEL_COUNT 3

#define SSP_ACCEL_NAME "ssp-accelerometer"
static const char ssp_accel_device_name[] = SSP_ACCEL_NAME;

enum ssp_accel_3d_channel {
	SSP_CHANNEL_SCAN_INDEX_X,
	SSP_CHANNEL_SCAN_INDEX_Y,
	SSP_CHANNEL_SCAN_INDEX_Z,
	SSP_CHANNEL_SCAN_INDEX_TIME,
};

static int ssp_accel_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,  int *val,
			      int *val2, long mask)
{
	u32 t;
	struct ssp_data *data = dev_get_drvdata(indio_dev->dev.parent->parent);

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		t = ssp_get_sensor_delay(data, SSP_ACCELEROMETER_SENSOR);
		ssp_convert_to_freq(t, val, val2);
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		break;
	}

	return -EINVAL;
}

static int ssp_accel_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan, int val,
			       int val2, long mask)
{
	int ret;
	struct ssp_data *data = dev_get_drvdata(indio_dev->dev.parent->parent);

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		ret = ssp_convert_to_time(val, val2);
		ret = ssp_change_delay(data, SSP_ACCELEROMETER_SENSOR, ret);
		if (ret < 0)
			dev_err(&indio_dev->dev, "accel sensor enable fail\n");

		return ret;
	default:
		break;
	}

	return -EINVAL;
}

static struct iio_info ssp_accel_iio_info = {
	.read_raw = &ssp_accel_read_raw,
	.write_raw = &ssp_accel_write_raw,
};

static const unsigned long ssp_accel_scan_mask[] = { 0x7, 0, };

static const struct iio_chan_spec ssp_acc_channels[] = {
	SSP_CHANNEL_AG(IIO_ACCEL, IIO_MOD_X, SSP_CHANNEL_SCAN_INDEX_X),
	SSP_CHANNEL_AG(IIO_ACCEL, IIO_MOD_Y, SSP_CHANNEL_SCAN_INDEX_Y),
	SSP_CHANNEL_AG(IIO_ACCEL, IIO_MOD_Z, SSP_CHANNEL_SCAN_INDEX_Z),
	SSP_CHAN_TIMESTAMP(SSP_CHANNEL_SCAN_INDEX_TIME),
};

static int ssp_process_accel_data(struct iio_dev *indio_dev, void *buf,
				  int64_t timestamp)
{
	return ssp_common_process_data(indio_dev, buf, SSP_ACCELEROMETER_SIZE,
				       timestamp);
}

static const struct iio_buffer_setup_ops ssp_accel_buffer_ops = {
	.postenable = &ssp_common_buffer_postenable,
	.postdisable = &ssp_common_buffer_postdisable,
};

static int ssp_accel_probe(struct platform_device *pdev)
{
	int ret;
	struct iio_dev *indio_dev;
	struct ssp_sensor_data *spd;
	struct iio_buffer *buffer;

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

	spd = iio_priv(indio_dev);

	spd->process_data = ssp_process_accel_data;
	spd->type = SSP_ACCELEROMETER_SENSOR;

	indio_dev->name = ssp_accel_device_name;
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->dev.of_node = pdev->dev.of_node;
	indio_dev->info = &ssp_accel_iio_info;
	indio_dev->modes = INDIO_BUFFER_SOFTWARE;
	indio_dev->channels = ssp_acc_channels;
	indio_dev->num_channels = ARRAY_SIZE(ssp_acc_channels);
	indio_dev->available_scan_masks = ssp_accel_scan_mask;

	buffer = devm_iio_kfifo_allocate(&pdev->dev);
	if (!buffer)
		return -ENOMEM;

	iio_device_attach_buffer(indio_dev, buffer);

	indio_dev->setup_ops = &ssp_accel_buffer_ops;

	platform_set_drvdata(pdev, indio_dev);

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		return ret;

	/* ssp registering should be done after all iio setup */
	ssp_register_consumer(indio_dev, SSP_ACCELEROMETER_SENSOR);

	return 0;
}

static int ssp_accel_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);

	iio_device_unregister(indio_dev);

	return 0;
}

static struct platform_driver ssp_accel_driver = {
	.driver = {
		.name = SSP_ACCEL_NAME,
	},
	.probe = ssp_accel_probe,
	.remove =  ssp_accel_remove,
};

module_platform_driver(ssp_accel_driver);

MODULE_AUTHOR("Karol Wrona <k.wrona@samsung.com>");
MODULE_DESCRIPTION("Samsung sensorhub accelerometers driver");
MODULE_LICENSE("GPL");