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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2011 Jonathan Cameron
*
* Buffer handling elements of industrial I/O reference driver.
* Uses the kfifo buffer.
*
* To test without hardware use the sysfs trigger.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/bitmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include "iio_simple_dummy.h"
/* Some fake data */
static const s16 fakedata[] = {
[DUMMY_INDEX_VOLTAGE_0] = 7,
[DUMMY_INDEX_DIFFVOLTAGE_1M2] = -33,
[DUMMY_INDEX_DIFFVOLTAGE_3M4] = -2,
[DUMMY_INDEX_ACCELX] = 344,
};
/**
* iio_simple_dummy_trigger_h() - the trigger handler function
* @irq: the interrupt number
* @p: private data - always a pointer to the poll func.
*
* This is the guts of buffered capture. On a trigger event occurring,
* if the pollfunc is attached then this handler is called as a threaded
* interrupt (and hence may sleep). It is responsible for grabbing data
* from the device and pushing it into the associated buffer.
*/
static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
int i = 0, j;
u16 *data;
data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
if (!data)
goto done;
/*
* Three common options here:
* hardware scans:
* certain combinations of channels make up a fast read. The capture
* will consist of all of them. Hence we just call the grab data
* function and fill the buffer without processing.
* software scans:
* can be considered to be random access so efficient reading is just
* a case of minimal bus transactions.
* software culled hardware scans:
* occasionally a driver may process the nearest hardware scan to avoid
* storing elements that are not desired. This is the fiddliest option
* by far.
* Here let's pretend we have random access. And the values are in the
* constant table fakedata.
*/
for_each_set_bit(j, indio_dev->active_scan_mask, indio_dev->masklength)
data[i++] = fakedata[j];
iio_push_to_buffers_with_timestamp(indio_dev, data,
iio_get_time_ns(indio_dev));
kfree(data);
done:
/*
* Tell the core we are done with this trigger and ready for the
* next one.
*/
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_buffer_setup_ops iio_simple_dummy_buffer_setup_ops = {
};
int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev)
{
return iio_triggered_buffer_setup(indio_dev, NULL,
iio_simple_dummy_trigger_h,
&iio_simple_dummy_buffer_setup_ops);
}
/**
* iio_simple_dummy_unconfigure_buffer() - release buffer resources
* @indio_dev: device instance state
*/
void iio_simple_dummy_unconfigure_buffer(struct iio_dev *indio_dev)
{
iio_triggered_buffer_cleanup(indio_dev);
}
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