1/*
2 * itg3200_buffer.c -- support InvenSense ITG3200
3 *                     Digital 3-Axis Gyroscope driver
4 *
5 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
6 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
7 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/slab.h>
15#include <linux/i2c.h>
16#include <linux/interrupt.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/buffer.h>
20#include <linux/iio/trigger.h>
21#include <linux/iio/trigger_consumer.h>
22#include <linux/iio/triggered_buffer.h>
23#include <linux/iio/gyro/itg3200.h>
24
25
26static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf)
27{
28	u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H;
29	struct i2c_msg msg[2] = {
30		{
31			.addr = i2c->addr,
32			.flags = i2c->flags,
33			.len = 1,
34			.buf = &tx,
35		},
36		{
37			.addr = i2c->addr,
38			.flags = i2c->flags | I2C_M_RD,
39			.len = ITG3200_SCAN_ELEMENTS * sizeof(s16),
40			.buf = (char *)&buf,
41		},
42	};
43
44	return i2c_transfer(i2c->adapter, msg, 2);
45}
46
47static irqreturn_t itg3200_trigger_handler(int irq, void *p)
48{
49	struct iio_poll_func *pf = p;
50	struct iio_dev *indio_dev = pf->indio_dev;
51	struct itg3200 *st = iio_priv(indio_dev);
52	__be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)];
53
54	int ret = itg3200_read_all_channels(st->i2c, buf);
55	if (ret < 0)
56		goto error_ret;
57
58	iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp);
59
60	iio_trigger_notify_done(indio_dev->trig);
61
62error_ret:
63	return IRQ_HANDLED;
64}
65
66int itg3200_buffer_configure(struct iio_dev *indio_dev)
67{
68	return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
69		itg3200_trigger_handler, NULL);
70}
71
72void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
73{
74	iio_triggered_buffer_cleanup(indio_dev);
75}
76
77
78static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
79		bool state)
80{
81	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
82	int ret;
83	u8 msc;
84
85	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
86	if (ret)
87		goto error_ret;
88
89	if (state)
90		msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
91	else
92		msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;
93
94	ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
95	if (ret)
96		goto error_ret;
97
98error_ret:
99	return ret;
100
101}
102
103static const struct iio_trigger_ops itg3200_trigger_ops = {
104	.owner = THIS_MODULE,
105	.set_trigger_state = &itg3200_data_rdy_trigger_set_state,
106};
107
108int itg3200_probe_trigger(struct iio_dev *indio_dev)
109{
110	int ret;
111	struct itg3200 *st = iio_priv(indio_dev);
112
113	st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
114				     indio_dev->id);
115	if (!st->trig)
116		return -ENOMEM;
117
118	ret = request_irq(st->i2c->irq,
119			  &iio_trigger_generic_data_rdy_poll,
120			  IRQF_TRIGGER_RISING,
121			  "itg3200_data_rdy",
122			  st->trig);
123	if (ret)
124		goto error_free_trig;
125
126
127	st->trig->dev.parent = &st->i2c->dev;
128	st->trig->ops = &itg3200_trigger_ops;
129	iio_trigger_set_drvdata(st->trig, indio_dev);
130	ret = iio_trigger_register(st->trig);
131	if (ret)
132		goto error_free_irq;
133
134	/* select default trigger */
135	indio_dev->trig = iio_trigger_get(st->trig);
136
137	return 0;
138
139error_free_irq:
140	free_irq(st->i2c->irq, st->trig);
141error_free_trig:
142	iio_trigger_free(st->trig);
143	return ret;
144}
145
146void itg3200_remove_trigger(struct iio_dev *indio_dev)
147{
148	struct itg3200 *st = iio_priv(indio_dev);
149
150	iio_trigger_unregister(st->trig);
151	free_irq(st->i2c->irq, st->trig);
152	iio_trigger_free(st->trig);
153}
154