blob: df4045203a0717c40613b2297c9f85a855333f68 [file] [log] [blame]
/*
* STMicroelectronics sensors buffer library driver
*
* Copyright 2012-2013 STMicroelectronics Inc.
*
* Denis Ciocca <denis.ciocca@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/interrupt.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/irqreturn.h>
#include <linux/iio/common/st_sensors.h>
static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
{
int i;
struct st_sensor_data *sdata = iio_priv(indio_dev);
unsigned int num_data_channels = sdata->num_data_channels;
for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
const struct iio_chan_spec *channel = &indio_dev->channels[i];
unsigned int bytes_to_read =
DIV_ROUND_UP(channel->scan_type.realbits +
channel->scan_type.shift, 8);
unsigned int storage_bytes =
channel->scan_type.storagebits >> 3;
buf = PTR_ALIGN(buf, storage_bytes);
if (sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
channel->address,
bytes_to_read, buf,
sdata->multiread_bit) <
bytes_to_read)
return -EIO;
/* Advance the buffer pointer */
buf += storage_bytes;
}
return 0;
}
irqreturn_t st_sensors_trigger_handler(int irq, void *p)
{
int len;
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct st_sensor_data *sdata = iio_priv(indio_dev);
s64 timestamp;
/*
* If we do timetamping here, do it before reading the values, because
* once we've read the values, new interrupts can occur (when using
* the hardware trigger) and the hw_timestamp may get updated.
* By storing it in a local variable first, we are safe.
*/
if (iio_trigger_using_own(indio_dev))
timestamp = sdata->hw_timestamp;
else
timestamp = iio_get_time_ns(indio_dev);
len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
if (len < 0)
goto st_sensors_get_buffer_element_error;
iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
timestamp);
st_sensors_get_buffer_element_error:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
EXPORT_SYMBOL(st_sensors_trigger_handler);
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer");
MODULE_LICENSE("GPL v2");