1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
149 lines
3.3 KiB
C
149 lines
3.3 KiB
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:
|
|
*/
|