]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* linux/drivers/char/scx200_gpio.c |
2 | ||
3 | National Semiconductor SCx200 GPIO driver. Allows a user space | |
4 | process to play with the GPIO pins. | |
5 | ||
6 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */ | |
7 | ||
8 | #include <linux/config.h> | |
9 | #include <linux/fs.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/init.h> | |
14 | #include <asm/uaccess.h> | |
15 | #include <asm/io.h> | |
16 | ||
17 | #include <linux/scx200_gpio.h> | |
18 | ||
19 | #define NAME "scx200_gpio" | |
20 | ||
21 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); | |
22 | MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver"); | |
23 | MODULE_LICENSE("GPL"); | |
24 | ||
25 | static int major = 0; /* default to dynamic major */ | |
26 | module_param(major, int, 0); | |
27 | MODULE_PARM_DESC(major, "Major device number"); | |
28 | ||
29 | static ssize_t scx200_gpio_write(struct file *file, const char __user *data, | |
30 | size_t len, loff_t *ppos) | |
31 | { | |
32 | unsigned m = iminor(file->f_dentry->d_inode); | |
33 | size_t i; | |
34 | ||
35 | for (i = 0; i < len; ++i) { | |
36 | char c; | |
37 | if (get_user(c, data+i)) | |
38 | return -EFAULT; | |
39 | switch (c) | |
40 | { | |
41 | case '0': | |
42 | scx200_gpio_set(m, 0); | |
43 | break; | |
44 | case '1': | |
45 | scx200_gpio_set(m, 1); | |
46 | break; | |
47 | case 'O': | |
48 | printk(KERN_INFO NAME ": GPIO%d output enabled\n", m); | |
49 | scx200_gpio_configure(m, ~1, 1); | |
50 | break; | |
51 | case 'o': | |
52 | printk(KERN_INFO NAME ": GPIO%d output disabled\n", m); | |
53 | scx200_gpio_configure(m, ~1, 0); | |
54 | break; | |
55 | case 'T': | |
56 | printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m); | |
57 | scx200_gpio_configure(m, ~2, 2); | |
58 | break; | |
59 | case 't': | |
60 | printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m); | |
61 | scx200_gpio_configure(m, ~2, 0); | |
62 | break; | |
63 | case 'P': | |
64 | printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m); | |
65 | scx200_gpio_configure(m, ~4, 4); | |
66 | break; | |
67 | case 'p': | |
68 | printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m); | |
69 | scx200_gpio_configure(m, ~4, 0); | |
70 | break; | |
71 | } | |
72 | } | |
73 | ||
74 | return len; | |
75 | } | |
76 | ||
77 | static ssize_t scx200_gpio_read(struct file *file, char __user *buf, | |
78 | size_t len, loff_t *ppos) | |
79 | { | |
80 | unsigned m = iminor(file->f_dentry->d_inode); | |
81 | int value; | |
82 | ||
83 | value = scx200_gpio_get(m); | |
84 | if (put_user(value ? '1' : '0', buf)) | |
85 | return -EFAULT; | |
86 | ||
87 | return 1; | |
88 | } | |
89 | ||
90 | static int scx200_gpio_open(struct inode *inode, struct file *file) | |
91 | { | |
92 | unsigned m = iminor(inode); | |
93 | if (m > 63) | |
94 | return -EINVAL; | |
95 | return nonseekable_open(inode, file); | |
96 | } | |
97 | ||
98 | static int scx200_gpio_release(struct inode *inode, struct file *file) | |
99 | { | |
100 | return 0; | |
101 | } | |
102 | ||
103 | ||
104 | static struct file_operations scx200_gpio_fops = { | |
105 | .owner = THIS_MODULE, | |
106 | .write = scx200_gpio_write, | |
107 | .read = scx200_gpio_read, | |
108 | .open = scx200_gpio_open, | |
109 | .release = scx200_gpio_release, | |
110 | }; | |
111 | ||
112 | static int __init scx200_gpio_init(void) | |
113 | { | |
114 | int r; | |
115 | ||
116 | printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n"); | |
117 | ||
118 | if (!scx200_gpio_present()) { | |
119 | printk(KERN_ERR NAME ": no SCx200 gpio pins available\n"); | |
120 | return -ENODEV; | |
121 | } | |
122 | ||
123 | r = register_chrdev(major, NAME, &scx200_gpio_fops); | |
124 | if (r < 0) { | |
125 | printk(KERN_ERR NAME ": unable to register character device\n"); | |
126 | return r; | |
127 | } | |
128 | if (!major) { | |
129 | major = r; | |
130 | printk(KERN_DEBUG NAME ": got dynamic major %d\n", major); | |
131 | } | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static void __exit scx200_gpio_cleanup(void) | |
137 | { | |
138 | unregister_chrdev(major, NAME); | |
139 | } | |
140 | ||
141 | module_init(scx200_gpio_init); | |
142 | module_exit(scx200_gpio_cleanup); | |
143 | ||
144 | /* | |
145 | Local variables: | |
146 | compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules" | |
147 | c-basic-offset: 8 | |
148 | End: | |
149 | */ |