[linux-2.6-block.git] / drivers / char / scx200_gpio.c

/* linux/drivers/char/scx200_gpio.c 

   National Semiconductor SCx200 GPIO driver.  Allows a user space
   process to play with the GPIO pins.

   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */

#include <linux/config.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/scx200_gpio.h>

#define NAME "scx200_gpio"

MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
MODULE_LICENSE("GPL");

static int major = 0;		/* default to dynamic major */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");

static ssize_t scx200_gpio_write(struct file *file, const char __user *data, 
				 size_t len, loff_t *ppos)
{
	unsigned m = iminor(file->f_dentry->d_inode);
	size_t i;

	for (i = 0; i < len; ++i) {
		char c;
		if (get_user(c, data+i))
			return -EFAULT;
		switch (c)
		{
		case '0': 
			scx200_gpio_set(m, 0); 
			break;
		case '1': 
			scx200_gpio_set(m, 1); 
			break;
		case 'O':
			printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
			scx200_gpio_configure(m, ~1, 1);
			break;
		case 'o':
			printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
			scx200_gpio_configure(m, ~1, 0);
			break;
		case 'T':
			printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
			scx200_gpio_configure(m, ~2, 2);
			break;
		case 't':
			printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
			scx200_gpio_configure(m, ~2, 0);
			break;
		case 'P':
			printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
			scx200_gpio_configure(m, ~4, 4);
			break;
		case 'p':
			printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
			scx200_gpio_configure(m, ~4, 0);
			break;
		}
	}

	return len;
}

static ssize_t scx200_gpio_read(struct file *file, char __user *buf,
				size_t len, loff_t *ppos)
{
	unsigned m = iminor(file->f_dentry->d_inode);
	int value;

	value = scx200_gpio_get(m);
	if (put_user(value ? '1' : '0', buf))
		return -EFAULT;
	
	return 1;
}

static int scx200_gpio_open(struct inode *inode, struct file *file)
{
	unsigned m = iminor(inode);
	if (m > 63)
		return -EINVAL;
	return nonseekable_open(inode, file);
}

static int scx200_gpio_release(struct inode *inode, struct file *file)
{
	return 0;
}


static struct file_operations scx200_gpio_fops = {
	.owner   = THIS_MODULE,
	.write   = scx200_gpio_write,
	.read    = scx200_gpio_read,
	.open    = scx200_gpio_open,
	.release = scx200_gpio_release,
};

static int __init scx200_gpio_init(void)
{
	int r;

	printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n");

	if (!scx200_gpio_present()) {
		printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
		return -ENODEV;
	}

	r = register_chrdev(major, NAME, &scx200_gpio_fops);
	if (r < 0) {
		printk(KERN_ERR NAME ": unable to register character device\n");
		return r;
	}
	if (!major) {
		major = r;
		printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
	}

	return 0;
}

static void __exit scx200_gpio_cleanup(void)
{
	unregister_chrdev(major, NAME);
}

module_init(scx200_gpio_init);
module_exit(scx200_gpio_cleanup);

/*
    Local variables:
        compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules"
        c-basic-offset: 8
    End:
*/
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	*/