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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2011 Jonathan Cameron
*
* Companion module to the iio simple dummy example driver.
* The purpose of this is to generate 'fake' event interrupts thus
* allowing that driver's code to be as close as possible to that of
* a normal driver talking to hardware. The approach used here
* is not intended to be general and just happens to work for this
* particular use case.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/sysfs.h>
#include "iio_dummy_evgen.h"
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/irq_sim.h>
/* Fiddly bit of faking and irq without hardware */
#define IIO_EVENTGEN_NO 10
/**
* struct iio_dummy_eventgen - event generator specific state
* @regs: irq regs we are faking
* @lock: protect the evgen state
* @inuse: mask of which irqs are connected
* @irq_sim_domain: irq simulator domain
*/
struct iio_dummy_eventgen {
struct iio_dummy_regs regs[IIO_EVENTGEN_NO];
struct mutex lock;
bool inuse[IIO_EVENTGEN_NO];
struct irq_domain *irq_sim_domain;
};
/* We can only ever have one instance of this 'device' */
static struct iio_dummy_eventgen *iio_evgen;
static int iio_dummy_evgen_create(void)
{
int ret;
iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL);
if (!iio_evgen)
return -ENOMEM;
iio_evgen->irq_sim_domain = irq_domain_create_sim(NULL,
IIO_EVENTGEN_NO);
if (IS_ERR(iio_evgen->irq_sim_domain)) {
ret = PTR_ERR(iio_evgen->irq_sim_domain);
kfree(iio_evgen);
return ret;
}
mutex_init(&iio_evgen->lock);
return 0;
}
/**
* iio_dummy_evgen_get_irq() - get an evgen provided irq for a device
*
* This function will give a free allocated irq to a client device.
* That irq can then be caused to 'fire' by using the associated sysfs file.
*/
int iio_dummy_evgen_get_irq(void)
{
int i, ret = 0;
if (!iio_evgen)
return -ENODEV;
mutex_lock(&iio_evgen->lock);
for (i = 0; i < IIO_EVENTGEN_NO; i++) {
if (!iio_evgen->inuse[i]) {
ret = irq_create_mapping(iio_evgen->irq_sim_domain, i);
iio_evgen->inuse[i] = true;
break;
}
}
mutex_unlock(&iio_evgen->lock);
if (i == IIO_EVENTGEN_NO)
return -ENOMEM;
return ret;
}
EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_irq);
/**
* iio_dummy_evgen_release_irq() - give the irq back.
* @irq: irq being returned to the pool
*
* Used by client driver instances to give the irqs back when they disconnect
*/
void iio_dummy_evgen_release_irq(int irq)
{
struct irq_data *irqd = irq_get_irq_data(irq);
mutex_lock(&iio_evgen->lock);
iio_evgen->inuse[irqd_to_hwirq(irqd)] = false;
irq_dispose_mapping(irq);
mutex_unlock(&iio_evgen->lock);
}
EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq);
struct iio_dummy_regs *iio_dummy_evgen_get_regs(int irq)
{
struct irq_data *irqd = irq_get_irq_data(irq);
return &iio_evgen->regs[irqd_to_hwirq(irqd)];
}
EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_regs);
static void iio_dummy_evgen_free(void)
{
irq_domain_remove_sim(iio_evgen->irq_sim_domain);
kfree(iio_evgen);
}
static void iio_evgen_release(struct device *dev)
{
iio_dummy_evgen_free();
}
static ssize_t iio_evgen_poke(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
unsigned long event;
int ret, irq;
ret = kstrtoul(buf, 10, &event);
if (ret)
return ret;
iio_evgen->regs[this_attr->address].reg_id = this_attr->address;
iio_evgen->regs[this_attr->address].reg_data = event;
irq = irq_find_mapping(iio_evgen->irq_sim_domain, this_attr->address);
ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true);
if (ret)
return ret;
return len;
}
static IIO_DEVICE_ATTR(poke_ev0, S_IWUSR, NULL, &iio_evgen_poke, 0);
static IIO_DEVICE_ATTR(poke_ev1, S_IWUSR, NULL, &iio_evgen_poke, 1);
static IIO_DEVICE_ATTR(poke_ev2, S_IWUSR, NULL, &iio_evgen_poke, 2);
static IIO_DEVICE_ATTR(poke_ev3, S_IWUSR, NULL, &iio_evgen_poke, 3);
static IIO_DEVICE_ATTR(poke_ev4, S_IWUSR, NULL, &iio_evgen_poke, 4);
static IIO_DEVICE_ATTR(poke_ev5, S_IWUSR, NULL, &iio_evgen_poke, 5);
static IIO_DEVICE_ATTR(poke_ev6, S_IWUSR, NULL, &iio_evgen_poke, 6);
static IIO_DEVICE_ATTR(poke_ev7, S_IWUSR, NULL, &iio_evgen_poke, 7);
static IIO_DEVICE_ATTR(poke_ev8, S_IWUSR, NULL, &iio_evgen_poke, 8);
static IIO_DEVICE_ATTR(poke_ev9, S_IWUSR, NULL, &iio_evgen_poke, 9);
static struct attribute *iio_evgen_attrs[] = {
&iio_dev_attr_poke_ev0.dev_attr.attr,
&iio_dev_attr_poke_ev1.dev_attr.attr,
&iio_dev_attr_poke_ev2.dev_attr.attr,
&iio_dev_attr_poke_ev3.dev_attr.attr,
&iio_dev_attr_poke_ev4.dev_attr.attr,
&iio_dev_attr_poke_ev5.dev_attr.attr,
&iio_dev_attr_poke_ev6.dev_attr.attr,
&iio_dev_attr_poke_ev7.dev_attr.attr,
&iio_dev_attr_poke_ev8.dev_attr.attr,
&iio_dev_attr_poke_ev9.dev_attr.attr,
NULL,
};
static const struct attribute_group iio_evgen_group = {
.attrs = iio_evgen_attrs,
};
static const struct attribute_group *iio_evgen_groups[] = {
&iio_evgen_group,
NULL
};
static struct device iio_evgen_dev = {
.bus = &iio_bus_type,
.groups = iio_evgen_groups,
.release = &iio_evgen_release,
};
static __init int iio_dummy_evgen_init(void)
{
int ret = iio_dummy_evgen_create();
if (ret < 0)
return ret;
device_initialize(&iio_evgen_dev);
dev_set_name(&iio_evgen_dev, "iio_evgen");
ret = device_add(&iio_evgen_dev);
if (ret)
put_device(&iio_evgen_dev);
return ret;
}
module_init(iio_dummy_evgen_init);
static __exit void iio_dummy_evgen_exit(void)
{
device_unregister(&iio_evgen_dev);
}
module_exit(iio_dummy_evgen_exit);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO dummy driver");
MODULE_LICENSE("GPL v2");
|
