generic: rtl8366: use smi->num_ports and smi->ops->get_vlan_4k
[openwrt.git] / target / linux / generic / files / drivers / char / gpio_dev.c
1 /*
2 * character device wrapper for generic gpio layer
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
17 *
18 * Feedback, Bugs... blogic@openwrt.org
19 *
20 * dpg 20100106
21 */
22
23 #include <linux/module.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <asm/uaccess.h>
27 #include <asm/io.h>
28 #include <asm/gpio.h>
29 #include <asm/atomic.h>
30 #include <linux/init.h>
31 #include <linux/genhd.h>
32 #include <linux/device.h>
33 #include <linux/platform_device.h>
34 #include <linux/gpio_dev.h>
35
36 #define DRVNAME "gpiodev"
37 #define DEVNAME "gpio"
38
39 static int dev_major;
40 static struct class *gpiodev_class;
41
42
43 /* third argument of user space ioctl ('arg' here) contains the <pin> */
44 static int
45 gpio_ioctl(struct inode * inode, struct file * file, unsigned int cmd,
46 unsigned long arg)
47 {
48 int retval = 0;
49
50 switch (cmd)
51 {
52 case GPIO_GET:
53 retval = gpio_get_value(arg);
54 break;
55 case GPIO_SET:
56 gpio_set_value(arg, 1);
57 break;
58 case GPIO_CLEAR:
59 gpio_set_value(arg, 0);
60 break;
61 case GPIO_DIR_IN:
62 retval = gpio_direction_input(arg);
63 break;
64 case GPIO_DIR_OUT:
65 retval = gpio_direction_output(arg, 0);
66 break;
67 case GPIO_DIR_HIGH:
68 retval = gpio_direction_output(arg, 1);
69 break;
70 case GPIO_REQUEST:
71 /* should be first ioctl operation on <pin> */
72 retval = gpio_request(arg, DRVNAME);
73 break;
74 case GPIO_FREE:
75 /* should be last ioctl operation on <pin> */
76 /* may be needed first if previous user missed this ioctl */
77 gpio_free(arg);
78 break;
79 case GPIO_CAN_SLEEP:
80 retval = gpio_cansleep(arg);
81 break;
82 default:
83 retval = -EINVAL;
84 /* = -ENOTTY; // correct return but ... */
85 break;
86 }
87 return retval;
88 }
89
90 /* Allow co-incident opens */
91 static int
92 gpio_open(struct inode *inode, struct file *file)
93 {
94 int result = 0;
95 unsigned int dev_minor = MINOR(inode->i_rdev);
96
97 if (dev_minor != 0)
98 {
99 printk(KERN_ERR DRVNAME ": trying to access unknown minor device -> %d\n", dev_minor);
100 result = -ENODEV;
101 goto out;
102 }
103 out:
104 return result;
105 }
106
107 static int
108 gpio_close(struct inode * inode, struct file * file)
109 {
110 /* could track all <pin>s requested by this fd and gpio_free()
111 * them here
112 */
113 return 0;
114 }
115
116 struct file_operations gpio_fops = {
117 ioctl: gpio_ioctl,
118 open: gpio_open,
119 release: gpio_close
120 };
121
122 static int
123 gpio_probe(struct platform_device *dev)
124 {
125 int result = 0;
126
127 dev_major = register_chrdev(0, DEVNAME, &gpio_fops);
128 if (!dev_major)
129 {
130 printk(KERN_ERR DRVNAME ": Error whilst opening %s \n", DEVNAME);
131 result = -ENODEV;
132 goto out;
133 }
134 gpiodev_class = class_create(THIS_MODULE, DRVNAME);
135 device_create(gpiodev_class, NULL, MKDEV(dev_major, 0), dev, DEVNAME);
136 printk(KERN_INFO DRVNAME ": gpio device registered with major %d\n", dev_major);
137 out:
138 return result;
139 }
140
141 static int
142 gpio_remove(struct platform_device *dev)
143 {
144 unregister_chrdev(dev_major, DEVNAME);
145 return 0;
146 }
147
148 static struct
149 platform_driver gpio_driver = {
150 .probe = gpio_probe,
151 .remove = gpio_remove,
152 .driver = {
153 .name = "GPIODEV",
154 .owner = THIS_MODULE,
155 },
156 };
157
158 static int __init
159 gpio_mod_init(void)
160 {
161 int ret = platform_driver_register(&gpio_driver);
162 if (ret)
163 printk(KERN_INFO DRVNAME ": Error registering platfom driver!\n");
164
165 return ret;
166 }
167
168 static void __exit
169 gpio_mod_exit(void)
170 {
171 platform_driver_unregister(&gpio_driver);
172 }
173
174 module_init (gpio_mod_init);
175 module_exit (gpio_mod_exit);
176
177 MODULE_LICENSE("GPL");
178 MODULE_AUTHOR("John Crispin / OpenWrt +");
179 MODULE_DESCRIPTION("Character device for for generic gpio api");
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