ia64/linux-2.6.18-xen.hg

view drivers/char/nsc_gpio.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /* linux/drivers/char/nsc_gpio.c
3 National Semiconductor common GPIO device-file/VFS methods.
4 Allows a user space process to control the GPIO pins.
6 Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
7 Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>
8 */
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>
17 #include <linux/platform_device.h>
18 #include <asm/uaccess.h>
19 #include <asm/io.h>
21 #define NAME "nsc_gpio"
23 void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index)
24 {
25 /* retrieve current config w/o changing it */
26 u32 config = amp->gpio_config(index, ~0, 0);
28 /* user requested via 'v' command, so its INFO */
29 dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n",
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 */
37 (config & 64) ? "DEBOUNCE" : "", /* debounce */
39 amp->gpio_get(index), amp->gpio_current(index));
40 }
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;
47 struct device *dev = amp->dev;
48 size_t i;
49 int err = 0;
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':
63 dev_dbg(dev, "GPIO%d output enabled\n", m);
64 amp->gpio_config(m, ~1, 1);
65 break;
66 case 'o':
67 dev_dbg(dev, "GPIO%d output disabled\n", m);
68 amp->gpio_config(m, ~1, 0);
69 break;
70 case 'T':
71 dev_dbg(dev, "GPIO%d output is push pull\n", m);
72 amp->gpio_config(m, ~2, 2);
73 break;
74 case 't':
75 dev_dbg(dev, "GPIO%d output is open drain\n", m);
76 amp->gpio_config(m, ~2, 0);
77 break;
78 case 'P':
79 dev_dbg(dev, "GPIO%d pull up enabled\n", m);
80 amp->gpio_config(m, ~4, 4);
81 break;
82 case 'p':
83 dev_dbg(dev, "GPIO%d pull up disabled\n", m);
84 amp->gpio_config(m, ~4, 0);
85 break;
86 case 'v':
87 /* View Current pin settings */
88 amp->gpio_dump(amp, m);
89 break;
90 case '\n':
91 /* end of settings string, do nothing */
92 break;
93 default:
94 dev_err(dev, "io%2d bad setting: chr<0x%2x>\n",
95 m, (int)c);
96 err++;
97 }
98 }
99 if (err)
100 return -EINVAL; /* full string handled, report error */
102 return len;
103 }
105 ssize_t nsc_gpio_read(struct file *file, char __user * buf,
106 size_t len, loff_t * ppos)
107 {
108 unsigned m = iminor(file->f_dentry->d_inode);
109 int value;
110 struct nsc_gpio_ops *amp = file->private_data;
112 value = amp->gpio_get(m);
113 if (put_user(value ? '1' : '0', buf))
114 return -EFAULT;
116 return 1;
117 }
119 /* common file-ops routines for both scx200_gpio and pc87360_gpio */
120 EXPORT_SYMBOL(nsc_gpio_write);
121 EXPORT_SYMBOL(nsc_gpio_read);
122 EXPORT_SYMBOL(nsc_gpio_dump);
124 static int __init nsc_gpio_init(void)
125 {
126 printk(KERN_DEBUG NAME " initializing\n");
127 return 0;
128 }
130 static void __exit nsc_gpio_cleanup(void)
131 {
132 printk(KERN_DEBUG NAME " cleanup\n");
133 }
135 module_init(nsc_gpio_init);
136 module_exit(nsc_gpio_cleanup);
138 MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
139 MODULE_DESCRIPTION("NatSemi GPIO Common Methods");
140 MODULE_LICENSE("GPL");