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
|
// SPDX-License-Identifier: GPL-2.0-only
/* linux/drivers/char/scx200_gpio.c
National Semiconductor SCx200 GPIO driver. Allows a user space
process to play with the GPIO pins.
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <asm/io.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/scx200_gpio.h>
#include <linux/nsc_gpio.h>
#define DRVNAME "scx200_gpio"
static struct platform_device *pdev;
MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
MODULE_LICENSE("GPL");
static int major = 0; /* default to dynamic major */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");
#define MAX_PINS 32 /* 64 later, when known ok */
struct nsc_gpio_ops scx200_gpio_ops = {
.owner = THIS_MODULE,
.gpio_config = scx200_gpio_configure,
.gpio_dump = nsc_gpio_dump,
.gpio_get = scx200_gpio_get,
.gpio_set = scx200_gpio_set,
.gpio_change = scx200_gpio_change,
.gpio_current = scx200_gpio_current
};
EXPORT_SYMBOL_GPL(scx200_gpio_ops);
static int scx200_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
file->private_data = &scx200_gpio_ops;
if (m >= MAX_PINS)
return -EINVAL;
return nonseekable_open(inode, file);
}
static int scx200_gpio_release(struct inode *inode, struct file *file)
{
return 0;
}
static const struct file_operations scx200_gpio_fileops = {
.owner = THIS_MODULE,
.write = nsc_gpio_write,
.read = nsc_gpio_read,
.open = scx200_gpio_open,
.release = scx200_gpio_release,
};
static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */
static int __init scx200_gpio_init(void)
{
int rc;
dev_t devid;
if (!scx200_gpio_present()) {
printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
return -ENODEV;
}
/* support dev_dbg() with pdev->dev */
pdev = platform_device_alloc(DRVNAME, 0);
if (!pdev)
return -ENOMEM;
rc = platform_device_add(pdev);
if (rc)
goto undo_malloc;
/* nsc_gpio uses dev_dbg(), so needs this */
scx200_gpio_ops.dev = &pdev->dev;
if (major) {
devid = MKDEV(major, 0);
rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
} else {
rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
major = MAJOR(devid);
}
if (rc < 0) {
dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
goto undo_platform_device_add;
}
cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
return 0; /* succeed */
undo_platform_device_add:
platform_device_del(pdev);
undo_malloc:
platform_device_put(pdev);
return rc;
}
static void __exit scx200_gpio_cleanup(void)
{
cdev_del(&scx200_gpio_cdev);
/* cdev_put(&scx200_gpio_cdev); */
unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
platform_device_unregister(pdev);
}
module_init(scx200_gpio_init);
module_exit(scx200_gpio_cleanup);
|
