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
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* dell-smo8800.c - Dell Latitude ACPI SMO8800/SMO8810 freefall sensor driver
*
* Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
* Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>
*
* This is loosely based on lis3lv02d driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define DRIVER_NAME "smo8800"
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
struct smo8800_device {
u32 irq; /* acpi device irq */
atomic_t counter; /* count after last read */
struct miscdevice miscdev; /* for /dev/freefall */
unsigned long misc_opened; /* whether the device is open */
wait_queue_head_t misc_wait; /* Wait queue for the misc dev */
struct device *dev; /* acpi device */
};
static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
{
struct smo8800_device *smo8800 = data;
atomic_inc(&smo8800->counter);
wake_up_interruptible(&smo8800->misc_wait);
return IRQ_WAKE_THREAD;
}
static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
{
struct smo8800_device *smo8800 = data;
dev_info(smo8800->dev, "detected free fall\n");
return IRQ_HANDLED;
}
static acpi_status smo8800_get_resource(struct acpi_resource *resource,
void *context)
{
struct acpi_resource_extended_irq *irq;
if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
return AE_OK;
irq = &resource->data.extended_irq;
if (!irq || !irq->interrupt_count)
return AE_OK;
*((u32 *)context) = irq->interrupts[0];
return AE_CTRL_TERMINATE;
}
static u32 smo8800_get_irq(struct acpi_device *device)
{
u32 irq = 0;
acpi_status status;
status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
smo8800_get_resource, &irq);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev, "acpi_walk_resources failed\n");
return 0;
}
return irq;
}
static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
size_t count, loff_t *pos)
{
struct smo8800_device *smo8800 = container_of(file->private_data,
struct smo8800_device, miscdev);
u32 data = 0;
unsigned char byte_data = 0;
ssize_t retval = 1;
if (count < 1)
return -EINVAL;
atomic_set(&smo8800->counter, 0);
retval = wait_event_interruptible(smo8800->misc_wait,
(data = atomic_xchg(&smo8800->counter, 0)));
if (retval)
return retval;
byte_data = 1;
retval = 1;
if (data < 255)
byte_data = data;
else
byte_data = 255;
if (put_user(byte_data, buf))
retval = -EFAULT;
return retval;
}
static int smo8800_misc_open(struct inode *inode, struct file *file)
{
struct smo8800_device *smo8800 = container_of(file->private_data,
struct smo8800_device, miscdev);
if (test_and_set_bit(0, &smo8800->misc_opened))
return -EBUSY; /* already open */
atomic_set(&smo8800->counter, 0);
return 0;
}
static int smo8800_misc_release(struct inode *inode, struct file *file)
{
struct smo8800_device *smo8800 = container_of(file->private_data,
struct smo8800_device, miscdev);
clear_bit(0, &smo8800->misc_opened); /* release the device */
return 0;
}
static const struct file_operations smo8800_misc_fops = {
.owner = THIS_MODULE,
.read = smo8800_misc_read,
.open = smo8800_misc_open,
.release = smo8800_misc_release,
};
static int smo8800_add(struct acpi_device *device)
{
int err;
struct smo8800_device *smo8800;
smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);
if (!smo8800) {
dev_err(&device->dev, "failed to allocate device data\n");
return -ENOMEM;
}
smo8800->dev = &device->dev;
smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
smo8800->miscdev.name = "freefall";
smo8800->miscdev.fops = &smo8800_misc_fops;
init_waitqueue_head(&smo8800->misc_wait);
err = misc_register(&smo8800->miscdev);
if (err) {
dev_err(&device->dev, "failed to register misc dev: %d\n", err);
return err;
}
device->driver_data = smo8800;
smo8800->irq = smo8800_get_irq(device);
if (!smo8800->irq) {
dev_err(&device->dev, "failed to obtain IRQ\n");
err = -EINVAL;
goto error;
}
err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,
smo8800_interrupt_thread,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
DRIVER_NAME, smo8800);
if (err) {
dev_err(&device->dev,
"failed to request thread for IRQ %d: %d\n",
smo8800->irq, err);
goto error;
}
dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
smo8800->irq);
return 0;
error:
misc_deregister(&smo8800->miscdev);
return err;
}
static int smo8800_remove(struct acpi_device *device)
{
struct smo8800_device *smo8800 = device->driver_data;
free_irq(smo8800->irq, smo8800);
misc_deregister(&smo8800->miscdev);
dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
return 0;
}
static const struct acpi_device_id smo8800_ids[] = {
{ "SMO8800", 0 },
{ "SMO8810", 0 },
{ "", 0 },
};
MODULE_DEVICE_TABLE(acpi, smo8800_ids);
static struct acpi_driver smo8800_driver = {
.name = DRIVER_NAME,
.class = "Latitude",
.ids = smo8800_ids,
.ops = {
.add = smo8800_add,
.remove = smo8800_remove,
},
.owner = THIS_MODULE,
};
module_acpi_driver(smo8800_driver);
MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO8800/SMO8810)");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sonal Santan, Pali Rohár");
|
