drivers/iio/accel/st_accel_buffer.c

/*
 * STMicroelectronics accelerometers driver
 *
 * Copyright 2012-2013 STMicroelectronics Inc.
 *
 * Denis Ciocca <denis.ciocca@st.com>
 *
 * Licensed under the GPL-2.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#include <linux/iio/common/st_sensors.h>
#include "st_accel.h"

int st_accel_trig_set_state(struct iio_trigger *trig, bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);

	return st_sensors_set_dataready_irq(indio_dev, state);
}

static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
{
	int err;
	struct st_sensor_data *adata = iio_priv(indio_dev);

	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
	if (adata->buffer_data == NULL) {
		err = -ENOMEM;
		goto allocate_memory_error;
	}

	err = st_sensors_set_axis_enable(indio_dev,
					(u8)indio_dev->active_scan_mask[0]);
	if (err < 0) {
		printk("SUN-5941: %s set_axis_enable %d\n", __PRETTY_FUNCTION__, err);
		goto st_sensors_set_axis_enable_error;
	}

	err = iio_triggered_buffer_postenable(indio_dev);
	if (err < 0) {
		printk("SUN-5941: %s postenable %d\n", __PRETTY_FUNCTION__, err);
		goto iio_triggered_buffer_postenable_error;
	}

	st_sensors_set_enable(indio_dev, true);

	return err;

iio_triggered_buffer_postenable_error:
	st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
st_sensors_set_axis_enable_error:
	kfree(adata->buffer_data);
allocate_memory_error:
	return err;
}

static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
{
	int err;
	struct st_sensor_data *adata = iio_priv(indio_dev);

	/* The ordering is important here as hw_irq_trigger must be set (which
	 * is done indirectly through iio_triggered_buffer_predisable) before
	 * any bus operation, otherwise the high priority looping interrupt
	 * thread can prevent this code from ever obtaining the bus lock.
	 */
	err = iio_triggered_buffer_predisable(indio_dev);
	if (err < 0)
		goto st_accel_buffer_predisable_error;

	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);

st_accel_buffer_predisable_error:
	kfree(adata->buffer_data);
	return err;
}

static int st_accel_buffer_postdisable(struct iio_dev *indio_dev)
{
	return st_sensors_set_enable(indio_dev, false);
}

static const struct iio_buffer_setup_ops st_accel_buffer_setup_ops = {
	.postenable = &st_accel_buffer_postenable,
	.predisable = &st_accel_buffer_predisable,
	.postdisable = &st_accel_buffer_postdisable,
};

int st_accel_allocate_ring(struct iio_dev *indio_dev)
{
	return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
		&st_sensors_trigger_handler, &st_accel_buffer_setup_ops);
}

void st_accel_deallocate_ring(struct iio_dev *indio_dev)
{
	iio_triggered_buffer_cleanup(indio_dev);
}

MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics accelerometers buffer");
MODULE_LICENSE("GPL v2");