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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*
* STMicroelectronics sensors trigger 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/common/st_sensors.h>
#include "st_sensors_core.h"
/**
* st_sensors_irq_handler() - top half of the IRQ-based triggers
* @irq: irq number
* @p: private handler data
*/
irqreturn_t st_sensors_irq_handler(int irq, void *p)
{
struct iio_trigger *trig = p;
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct st_sensor_data *sdata = iio_priv(indio_dev);
/* Get the time stamp as close in time as possible */
sdata->hw_timestamp = iio_get_time_ns(indio_dev);
return IRQ_WAKE_THREAD;
}
/**
* st_sensors_irq_thread() - bottom half of the IRQ-based triggers
* @irq: irq number
* @p: private handler data
*/
irqreturn_t st_sensors_irq_thread(int irq, void *p)
{
struct iio_trigger *trig = p;
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct st_sensor_data *sdata = iio_priv(indio_dev);
int ret;
/*
* If this trigger is backed by a hardware interrupt and we have a
* status register, check if this IRQ came from us
*/
if (sdata->sensor_settings->drdy_irq.addr_stat_drdy) {
u8 status;
ret = sdata->tf->read_byte(&sdata->tb, sdata->dev,
sdata->sensor_settings->drdy_irq.addr_stat_drdy,
&status);
if (ret < 0) {
dev_err(sdata->dev, "could not read channel status\n");
goto out_poll;
}
/*
* the lower bits of .active_scan_mask[0] is directly mapped
* to the channels on the sensor: either bit 0 for
* one-dimensional sensors, or e.g. x,y,z for accelerometers,
* gyroscopes or magnetometers. No sensor use more than 3
* channels, so cut the other status bits here.
*/
status &= 0x07;
/*
* If this was not caused by any channels on this sensor,
* return IRQ_NONE
*/
if (!indio_dev->active_scan_mask)
return IRQ_NONE;
if (!(status & (u8)indio_dev->active_scan_mask[0]))
return IRQ_NONE;
}
out_poll:
/* It's our IRQ: proceed to handle the register polling */
iio_trigger_poll_chained(p);
return IRQ_HANDLED;
}
int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
const struct iio_trigger_ops *trigger_ops)
{
int err, irq;
struct st_sensor_data *sdata = iio_priv(indio_dev);
unsigned long irq_trig;
sdata->trig = iio_trigger_alloc("%s-trigger", indio_dev->name);
if (sdata->trig == NULL) {
dev_err(&indio_dev->dev, "failed to allocate iio trigger.\n");
return -ENOMEM;
}
iio_trigger_set_drvdata(sdata->trig, indio_dev);
sdata->trig->ops = trigger_ops;
sdata->trig->dev.parent = sdata->dev;
irq = sdata->get_irq_data_ready(indio_dev);
irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
/*
* If the IRQ is triggered on falling edge, we need to mark the
* interrupt as active low, if the hardware supports this.
*/
if (irq_trig == IRQF_TRIGGER_FALLING) {
if (!sdata->sensor_settings->drdy_irq.addr_ihl) {
dev_err(&indio_dev->dev,
"falling edge specified for IRQ but hardware "
"only support rising edge, will request "
"rising edge\n");
irq_trig = IRQF_TRIGGER_RISING;
} else {
/* Set up INT active low i.e. falling edge */
err = st_sensors_write_data_with_mask(indio_dev,
sdata->sensor_settings->drdy_irq.addr_ihl,
sdata->sensor_settings->drdy_irq.mask_ihl, 1);
if (err < 0)
goto iio_trigger_free;
dev_info(&indio_dev->dev,
"interrupts on the falling edge\n");
}
} else if (irq_trig == IRQF_TRIGGER_RISING) {
dev_info(&indio_dev->dev,
"interrupts on the rising edge\n");
} else {
dev_err(&indio_dev->dev,
"unsupported IRQ trigger specified (%lx), only "
"rising and falling edges supported, enforce "
"rising edge\n", irq_trig);
irq_trig = IRQF_TRIGGER_RISING;
}
/*
* If the interrupt pin is Open Drain, by definition this
* means that the interrupt line may be shared with other
* peripherals. But to do this we also need to have a status
* register and mask to figure out if this sensor was firing
* the IRQ or not, so we can tell the interrupt handle that
* it was "our" interrupt.
*/
if (sdata->int_pin_open_drain &&
sdata->sensor_settings->drdy_irq.addr_stat_drdy)
irq_trig |= IRQF_SHARED;
/* Let's create an interrupt thread masking the hard IRQ here */
irq_trig |= IRQF_ONESHOT;
err = request_threaded_irq(sdata->get_irq_data_ready(indio_dev),
st_sensors_irq_handler,
st_sensors_irq_thread,
irq_trig,
sdata->trig->name,
sdata->trig);
if (err) {
dev_err(&indio_dev->dev, "failed to request trigger IRQ.\n");
goto iio_trigger_free;
}
err = iio_trigger_register(sdata->trig);
if (err < 0) {
dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
goto iio_trigger_register_error;
}
indio_dev->trig = iio_trigger_get(sdata->trig);
return 0;
iio_trigger_register_error:
free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
iio_trigger_free:
iio_trigger_free(sdata->trig);
return err;
}
EXPORT_SYMBOL(st_sensors_allocate_trigger);
void st_sensors_deallocate_trigger(struct iio_dev *indio_dev)
{
struct st_sensor_data *sdata = iio_priv(indio_dev);
iio_trigger_unregister(sdata->trig);
free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
iio_trigger_free(sdata->trig);
}
EXPORT_SYMBOL(st_sensors_deallocate_trigger);
int st_sensors_validate_device(struct iio_trigger *trig,
struct iio_dev *indio_dev)
{
struct iio_dev *indio = iio_trigger_get_drvdata(trig);
if (indio != indio_dev)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(st_sensors_validate_device);
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger");
MODULE_LICENSE("GPL v2");
|
