1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
// 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 len = 0;
u16 *data;
data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
if (!data)
goto done;
if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) {
/*
* 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.
*/
int i, j;
for (i = 0, j = 0;
i < bitmap_weight(indio_dev->active_scan_mask,
indio_dev->masklength);
i++, j++) {
j = find_next_bit(indio_dev->active_scan_mask,
indio_dev->masklength, j);
/* random access read from the 'device' */
data[i] = fakedata[j];
len += 2;
}
}
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);
}
|
