Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1ca5df0a JC |
2 | /* linux/drivers/char/nsc_gpio.c |
3 | ||
4 | National Semiconductor common GPIO device-file/VFS methods. | |
5 | Allows a user space process to control the GPIO pins. | |
6 | ||
7 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> | |
8 | Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com> | |
9 | */ | |
10 | ||
1ca5df0a JC |
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> |
7c0f6ba6 | 18 | #include <linux/uaccess.h> |
1ca5df0a JC |
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 | { | |
496ad9aa | 45 | unsigned m = iminor(file_inode(file)); |
1a66fdf0 | 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': | |
abecb6da | 71 | dev_dbg(dev, "GPIO%d output is push pull\n", m); |
1a66fdf0 JC |
72 | amp->gpio_config(m, ~2, 2); |
73 | break; | |
74 | case 't': | |
abecb6da | 75 | dev_dbg(dev, "GPIO%d output is open drain\n", m); |
1a66fdf0 JC |
76 | amp->gpio_config(m, ~2, 0); |
77 | break; | |
78 | case 'P': | |
f31000e5 | 79 | dev_dbg(dev, "GPIO%d pull up enabled\n", m); |
1a66fdf0 JC |
80 | amp->gpio_config(m, ~4, 4); |
81 | break; | |
82 | case 'p': | |
f31000e5 | 83 | dev_dbg(dev, "GPIO%d pull up disabled\n", m); |
1a66fdf0 JC |
84 | amp->gpio_config(m, ~4, 0); |
85 | break; | |
1a66fdf0 JC |
86 | case 'v': |
87 | /* View Current pin settings */ | |
f31000e5 | 88 | amp->gpio_dump(amp, m); |
1a66fdf0 JC |
89 | break; |
90 | case '\n': | |
91 | /* end of settings string, do nothing */ | |
92 | break; | |
93 | default: | |
f31000e5 JC |
94 | dev_err(dev, "io%2d bad setting: chr<0x%2x>\n", |
95 | m, (int)c); | |
1a66fdf0 JC |
96 | err++; |
97 | } | |
98 | } | |
99 | if (err) | |
100 | return -EINVAL; /* full string handled, report error */ | |
101 | ||
102 | return len; | |
103 | } | |
104 | ||
105 | ssize_t nsc_gpio_read(struct file *file, char __user * buf, | |
106 | size_t len, loff_t * ppos) | |
107 | { | |
496ad9aa | 108 | unsigned m = iminor(file_inode(file)); |
1a66fdf0 JC |
109 | int value; |
110 | struct nsc_gpio_ops *amp = file->private_data; | |
111 | ||
112 | value = amp->gpio_get(m); | |
113 | if (put_user(value ? '1' : '0', buf)) | |
114 | return -EFAULT; | |
115 | ||
116 | return 1; | |
117 | } | |
118 | ||
0e41ef3c | 119 | /* common file-ops routines for both scx200_gpio and pc87360_gpio */ |
1a66fdf0 JC |
120 | EXPORT_SYMBOL(nsc_gpio_write); |
121 | EXPORT_SYMBOL(nsc_gpio_read); | |
0e41ef3c | 122 | EXPORT_SYMBOL(nsc_gpio_dump); |
1ca5df0a JC |
123 | |
124 | static int __init nsc_gpio_init(void) | |
125 | { | |
126 | printk(KERN_DEBUG NAME " initializing\n"); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | static void __exit nsc_gpio_cleanup(void) | |
131 | { | |
132 | printk(KERN_DEBUG NAME " cleanup\n"); | |
133 | } | |
134 | ||
1ca5df0a JC |
135 | module_init(nsc_gpio_init); |
136 | module_exit(nsc_gpio_cleanup); | |
1a66fdf0 JC |
137 | |
138 | MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>"); | |
139 | MODULE_DESCRIPTION("NatSemi GPIO Common Methods"); | |
140 | MODULE_LICENSE("GPL"); |