summaryrefslogtreecommitdiffstats
path: root/drivers/iio/gyro/itg3200_buffer.c
blob: 56aac0a9b500b659285af88f6881d5f3cb1841f0 (plain)
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
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/*
 * itg3200_buffer.c -- support InvenSense ITG3200
 *                     Digital 3-Axis Gyroscope driver
 *
 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>

#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/gyro/itg3200.h>


static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf)
{
	u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H;
	struct i2c_msg msg[2] = {
		{
			.addr = i2c->addr,
			.flags = i2c->flags,
			.len = 1,
			.buf = &tx,
		},
		{
			.addr = i2c->addr,
			.flags = i2c->flags | I2C_M_RD,
			.len = ITG3200_SCAN_ELEMENTS * sizeof(s16),
			.buf = (char *)&buf,
		},
	};

	return i2c_transfer(i2c->adapter, msg, 2);
}

static irqreturn_t itg3200_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct itg3200 *st = iio_priv(indio_dev);
	/*
	 * Ensure correct alignment and padding including for the
	 * timestamp that may be inserted.
	 */
	struct {
		__be16 buf[ITG3200_SCAN_ELEMENTS];
		s64 ts __aligned(8);
	} scan;

	int ret = itg3200_read_all_channels(st->i2c, scan.buf);
	if (ret < 0)
		goto error_ret;

	iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);

error_ret:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

int itg3200_buffer_configure(struct iio_dev *indio_dev)
{
	return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
		itg3200_trigger_handler, NULL);
}

void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
{
	iio_triggered_buffer_cleanup(indio_dev);
}


static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
		bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	int ret;
	u8 msc;

	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
	if (ret)
		goto error_ret;

	if (state)
		msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
	else
		msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;

	ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
	if (ret)
		goto error_ret;

error_ret:
	return ret;

}

static const struct iio_trigger_ops itg3200_trigger_ops = {
	.set_trigger_state = &itg3200_data_rdy_trigger_set_state,
};

int itg3200_probe_trigger(struct iio_dev *indio_dev)
{
	int ret;
	struct itg3200 *st = iio_priv(indio_dev);

	st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
				     indio_dev->id);
	if (!st->trig)
		return -ENOMEM;

	ret = request_irq(st->i2c->irq,
			  &iio_trigger_generic_data_rdy_poll,
			  IRQF_TRIGGER_RISING,
			  "itg3200_data_rdy",
			  st->trig);
	if (ret)
		goto error_free_trig;


	st->trig->dev.parent = &st->i2c->dev;
	st->trig->ops = &itg3200_trigger_ops;
	iio_trigger_set_drvdata(st->trig, indio_dev);
	ret = iio_trigger_register(st->trig);
	if (ret)
		goto error_free_irq;

	/* select default trigger */
	indio_dev->trig = iio_trigger_get(st->trig);

	return 0;

error_free_irq:
	free_irq(st->i2c->irq, st->trig);
error_free_trig:
	iio_trigger_free(st->trig);
	return ret;
}

void itg3200_remove_trigger(struct iio_dev *indio_dev)
{
	struct itg3200 *st = iio_priv(indio_dev);

	iio_trigger_unregister(st->trig);
	free_irq(st->i2c->irq, st->trig);
	iio_trigger_free(st->trig);
}