[deliverable/linux.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);
Commit	Line	Data
62c83cde	1	/* linux/drivers/char/scx200_gpio.c
1da177e4 LT	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
62c83cde	29	static ssize_t scx200_gpio_write(struct file file, const char __user data,
1da177e4 LT	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;
62c83cde	37	if (get_user(c, data + i))
1da177e4	38	return -EFAULT;
62c83cde JC	39	switch (c) {
	40	case '0':
	41	scx200_gpio_set(m, 0);
1da177e4	42	break;
62c83cde JC	43	case '1':
62c83cde JC	44	scx200_gpio_set(m, 1);
1da177e4 LT	45	break;
	46	case 'O':
	47	printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
	48	scx200_gpio_configure(m, ~1, 1);
	49	break;
	50	case 'o':
	51	printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
	52	scx200_gpio_configure(m, ~1, 0);
	53	break;
	54	case 'T':
	55	printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
	56	scx200_gpio_configure(m, ~2, 2);
	57	break;
	58	case 't':
	59	printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
	60	scx200_gpio_configure(m, ~2, 0);
	61	break;
	62	case 'P':
	63	printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
	64	scx200_gpio_configure(m, ~4, 4);
	65	break;
	66	case 'p':
	67	printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
	68	scx200_gpio_configure(m, ~4, 0);
	69	break;
	70	}
	71	}
	72
	73	return len;
	74	}
	75
	76	static ssize_t scx200_gpio_read(struct file file, char __user buf,
	77	size_t len, loff_t *ppos)
	78	{
	79	unsigned m = iminor(file->f_dentry->d_inode);
	80	int value;
	81
	82	value = scx200_gpio_get(m);
	83	if (put_user(value ? '1' : '0', buf))
	84	return -EFAULT;
62c83cde	85
1da177e4 LT	86	return 1;
	87	}
	88
	89	static int scx200_gpio_open(struct inode inode, struct file file)
	90	{
	91	unsigned m = iminor(inode);
	92	if (m > 63)
	93	return -EINVAL;
	94	return nonseekable_open(inode, file);
	95	}
	96
	97	static int scx200_gpio_release(struct inode inode, struct file file)
	98	{
	99	return 0;
	100	}
	101
	102
	103	static struct file_operations scx200_gpio_fops = {
	104	.owner = THIS_MODULE,
	105	.write = scx200_gpio_write,
	106	.read = scx200_gpio_read,
	107	.open = scx200_gpio_open,
	108	.release = scx200_gpio_release,
	109	};
	110
	111	static int __init scx200_gpio_init(void)
	112	{
	113	int r;
	114
	115	printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n");
	116
	117	if (!scx200_gpio_present()) {
	118	printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
	119	return -ENODEV;
	120	}
	121
	122	r = register_chrdev(major, NAME, &scx200_gpio_fops);
	123	if (r < 0) {
	124	printk(KERN_ERR NAME ": unable to register character device\n");
	125	return r;
	126	}
	127	if (!major) {
	128	major = r;
	129	printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
	130	}
	131
	132	return 0;
	133	}
	134
	135	static void __exit scx200_gpio_cleanup(void)
	136	{
	137	unregister_chrdev(major, NAME);
	138	}
	139
	140	module_init(scx200_gpio_init);
	141	module_exit(scx200_gpio_cleanup);