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1ca5df0a JC |
1 | /* linux/drivers/char/nsc_gpio.c |
2 | ||
3 | National Semiconductor common GPIO device-file/VFS methods. | |
4 | Allows a user space process to control the GPIO pins. | |
5 | ||
6 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> | |
7 | Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com> | |
8 | */ | |
9 | ||
10 | #include <linux/config.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/nsc_gpio.h> | |
f31000e5 | 17 | #include <linux/platform_device.h> |
1ca5df0a JC |
18 | #include <asm/uaccess.h> |
19 | #include <asm/io.h> | |
20 | ||
21 | #define NAME "nsc_gpio" | |
22 | ||
f31000e5 | 23 | void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index) |
0e41ef3c | 24 | { |
f31000e5 JC |
25 | /* retrieve current config w/o changing it */ |
26 | u32 config = amp->gpio_config(index, ~0, 0); | |
27 | ||
28 | /* user requested via 'v' command, so its INFO */ | |
23916a8e | 29 | dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n", |
f31000e5 JC |
30 | index, config, |
31 | (config & 1) ? "OE" : "TS", /* output-enabled/tristate */ | |
32 | (config & 2) ? "PP" : "OD", /* push pull / open drain */ | |
33 | (config & 4) ? "PUE" : "PUD", /* pull up enabled/disabled */ | |
34 | (config & 8) ? "LOCKED" : "", /* locked / unlocked */ | |
35 | (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */ | |
36 | (config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */ | |
23916a8e JC |
37 | (config & 64) ? "DEBOUNCE" : "", /* debounce */ |
38 | ||
39 | amp->gpio_get(index), amp->gpio_current(index)); | |
0e41ef3c JC |
40 | } |
41 | ||
1a66fdf0 JC |
42 | ssize_t nsc_gpio_write(struct file *file, const char __user *data, |
43 | size_t len, loff_t *ppos) | |
44 | { | |
45 | unsigned m = iminor(file->f_dentry->d_inode); | |
46 | struct nsc_gpio_ops *amp = file->private_data; | |
f31000e5 | 47 | struct device *dev = amp->dev; |
1a66fdf0 JC |
48 | size_t i; |
49 | int err = 0; | |
50 | ||
51 | for (i = 0; i < len; ++i) { | |
52 | char c; | |
53 | if (get_user(c, data + i)) | |
54 | return -EFAULT; | |
55 | switch (c) { | |
56 | case '0': | |
57 | amp->gpio_set(m, 0); | |
58 | break; | |
59 | case '1': | |
60 | amp->gpio_set(m, 1); | |
61 | break; | |
62 | case 'O': | |
f31000e5 | 63 | dev_dbg(dev, "GPIO%d output enabled\n", m); |
1a66fdf0 JC |
64 | amp->gpio_config(m, ~1, 1); |
65 | break; | |
66 | case 'o': | |
f31000e5 | 67 | dev_dbg(dev, "GPIO%d output disabled\n", m); |
1a66fdf0 JC |
68 | amp->gpio_config(m, ~1, 0); |
69 | break; | |
70 | case 'T': | |
f31000e5 | 71 | dev_dbg(dev, "GPIO%d output is push pull\n", |
1a66fdf0 JC |
72 | m); |
73 | amp->gpio_config(m, ~2, 2); | |
74 | break; | |
75 | case 't': | |
f31000e5 | 76 | dev_dbg(dev, "GPIO%d output is open drain\n", |
1a66fdf0 JC |
77 | m); |
78 | amp->gpio_config(m, ~2, 0); | |
79 | break; | |
80 | case 'P': | |
f31000e5 | 81 | dev_dbg(dev, "GPIO%d pull up enabled\n", m); |
1a66fdf0 JC |
82 | amp->gpio_config(m, ~4, 4); |
83 | break; | |
84 | case 'p': | |
f31000e5 | 85 | dev_dbg(dev, "GPIO%d pull up disabled\n", m); |
1a66fdf0 JC |
86 | amp->gpio_config(m, ~4, 0); |
87 | break; | |
1a66fdf0 JC |
88 | case 'v': |
89 | /* View Current pin settings */ | |
f31000e5 | 90 | amp->gpio_dump(amp, m); |
1a66fdf0 JC |
91 | break; |
92 | case '\n': | |
93 | /* end of settings string, do nothing */ | |
94 | break; | |
95 | default: | |
f31000e5 JC |
96 | dev_err(dev, "io%2d bad setting: chr<0x%2x>\n", |
97 | m, (int)c); | |
1a66fdf0 JC |
98 | err++; |
99 | } | |
100 | } | |
101 | if (err) | |
102 | return -EINVAL; /* full string handled, report error */ | |
103 | ||
104 | return len; | |
105 | } | |
106 | ||
107 | ssize_t nsc_gpio_read(struct file *file, char __user * buf, | |
108 | size_t len, loff_t * ppos) | |
109 | { | |
110 | unsigned m = iminor(file->f_dentry->d_inode); | |
111 | int value; | |
112 | struct nsc_gpio_ops *amp = file->private_data; | |
113 | ||
114 | value = amp->gpio_get(m); | |
115 | if (put_user(value ? '1' : '0', buf)) | |
116 | return -EFAULT; | |
117 | ||
118 | return 1; | |
119 | } | |
120 | ||
0e41ef3c | 121 | /* common file-ops routines for both scx200_gpio and pc87360_gpio */ |
1a66fdf0 JC |
122 | EXPORT_SYMBOL(nsc_gpio_write); |
123 | EXPORT_SYMBOL(nsc_gpio_read); | |
0e41ef3c | 124 | EXPORT_SYMBOL(nsc_gpio_dump); |
1ca5df0a JC |
125 | |
126 | static int __init nsc_gpio_init(void) | |
127 | { | |
128 | printk(KERN_DEBUG NAME " initializing\n"); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static void __exit nsc_gpio_cleanup(void) | |
133 | { | |
134 | printk(KERN_DEBUG NAME " cleanup\n"); | |
135 | } | |
136 | ||
1ca5df0a JC |
137 | module_init(nsc_gpio_init); |
138 | module_exit(nsc_gpio_cleanup); | |
1a66fdf0 JC |
139 | |
140 | MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>"); | |
141 | MODULE_DESCRIPTION("NatSemi GPIO Common Methods"); | |
142 | MODULE_LICENSE("GPL"); |