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
|
/* 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/config.h>
#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 <asm/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 NAME "scx200_gpio"
#define DEVNAME NAME
static struct platform_device *pdev;
MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi 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");
struct nsc_gpio_ops scx200_access = {
.owner = THIS_MODULE,
.gpio_config = scx200_gpio_configure,
.gpio_dump = nsc_gpio_dump,
.gpio_get = scx200_gpio_get,
.gpio_set = scx200_gpio_set,
.gpio_set_high = scx200_gpio_set_high,
.gpio_set_low = scx200_gpio_set_low,
.gpio_change = scx200_gpio_change,
.gpio_current = scx200_gpio_current
};
static int scx200_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
file->private_data = &scx200_access;
if (m > 63)
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_fops = {
.owner = THIS_MODULE,
.write = nsc_gpio_write,
.read = nsc_gpio_read,
.open = scx200_gpio_open,
.release = scx200_gpio_release,
};
struct cdev *scx200_devices;
static int num_pins = 32;
static int __init scx200_gpio_init(void)
{
int rc, i;
dev_t dev = MKDEV(major, 0);
if (!scx200_gpio_present()) {
printk(KERN_ERR NAME ": no SCx200 gpio present\n");
return -ENODEV;
}
/* support dev_dbg() with pdev->dev */
pdev = platform_device_alloc(DEVNAME, 0);
if (!pdev)
return -ENOMEM;
rc = platform_device_add(pdev);
if (rc)
goto undo_malloc;
/* nsc_gpio uses dev_dbg(), so needs this */
scx200_access.dev = &pdev->dev;
if (major)
rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
else {
rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio");
major = MAJOR(dev);
}
if (rc < 0) {
dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
goto undo_platform_device_add;
}
scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL);
if (!scx200_devices) {
rc = -ENOMEM;
goto undo_chrdev_region;
}
for (i = 0; i < num_pins; i++) {
struct cdev *cdev = &scx200_devices[i];
cdev_init(cdev, &scx200_gpio_fops);
cdev->owner = THIS_MODULE;
rc = cdev_add(cdev, MKDEV(major, i), 1);
/* tolerate 'minor' errors */
if (rc)
dev_err(&pdev->dev, "Error %d on minor %d", rc, i);
}
return 0; /* succeed */
undo_chrdev_region:
unregister_chrdev_region(dev, num_pins);
undo_platform_device_add:
platform_device_del(pdev);
undo_malloc:
platform_device_put(pdev);
return rc;
}
static void __exit scx200_gpio_cleanup(void)
{
kfree(scx200_devices);
unregister_chrdev_region(MKDEV(major, 0), num_pins);
platform_device_unregister(pdev);
/* kfree(pdev); */
}
module_init(scx200_gpio_init);
module_exit(scx200_gpio_cleanup);
|
