android_kernel_motorola_sm6225/arch/sh/boards/mach-landisk/gio.c
Thomas Gleixner 52a94909f0 sh: Remove BKL from landisk gio.
The open function got the BKL via the big push down. Replace it by
preempt_enable/disable as this is sufficient for an UP machine.

The ioctl can be unlocked because there is no functionality which
requires serialization. The usage by multiple callers is broken with
and without the BKL due to the local static variable addr.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-10-16 14:42:33 +09:00

169 lines
3.3 KiB
C

/*
* arch/sh/boards/landisk/gio.c - driver for landisk
*
* This driver will also support the I-O DATA Device, Inc. LANDISK Board.
* LANDISK and USL-5P Button, LED and GIO driver drive function.
*
* Copylight (C) 2006 kogiidena
* Copylight (C) 2002 Atom Create Engineering Co., Ltd. *
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <mach-landisk/mach/gio.h>
#include <mach-landisk/mach/iodata_landisk.h>
#define DEVCOUNT 4
#define GIO_MINOR 2 /* GIO minor no. */
static dev_t dev;
static struct cdev *cdev_p;
static int openCnt;
static int gio_open(struct inode *inode, struct file *filp)
{
int minor;
int ret = -ENOENT;
preempt_disable();
minor = MINOR(inode->i_rdev);
if (minor < DEVCOUNT) {
if (openCnt > 0) {
ret = -EALREADY;
} else {
openCnt++;
ret = 0;
}
}
preempt_enable();
return ret;
}
static int gio_close(struct inode *inode, struct file *filp)
{
int minor;
minor = MINOR(inode->i_rdev);
if (minor < DEVCOUNT) {
openCnt--;
}
return 0;
}
static long gio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
unsigned int data;
static unsigned int addr = 0;
if (cmd & 0x01) { /* write */
if (copy_from_user(&data, (int *)arg, sizeof(int))) {
return -EFAULT;
}
}
switch (cmd) {
case GIODRV_IOCSGIOSETADDR: /* address set */
addr = data;
break;
case GIODRV_IOCSGIODATA1: /* write byte */
ctrl_outb((unsigned char)(0x0ff & data), addr);
break;
case GIODRV_IOCSGIODATA2: /* write word */
if (addr & 0x01) {
return -EFAULT;
}
ctrl_outw((unsigned short int)(0x0ffff & data), addr);
break;
case GIODRV_IOCSGIODATA4: /* write long */
if (addr & 0x03) {
return -EFAULT;
}
ctrl_outl(data, addr);
break;
case GIODRV_IOCGGIODATA1: /* read byte */
data = ctrl_inb(addr);
break;
case GIODRV_IOCGGIODATA2: /* read word */
if (addr & 0x01) {
return -EFAULT;
}
data = ctrl_inw(addr);
break;
case GIODRV_IOCGGIODATA4: /* read long */
if (addr & 0x03) {
return -EFAULT;
}
data = ctrl_inl(addr);
break;
default:
return -EFAULT;
break;
}
if ((cmd & 0x01) == 0) { /* read */
if (copy_to_user((int *)arg, &data, sizeof(int))) {
return -EFAULT;
}
}
return 0;
}
static const struct file_operations gio_fops = {
.owner = THIS_MODULE,
.open = gio_open, /* open */
.release = gio_close, /* release */
.unlocked_ioctl = gio_ioctl,
};
static int __init gio_init(void)
{
int error;
printk(KERN_INFO "gio: driver initialized\n");
openCnt = 0;
if ((error = alloc_chrdev_region(&dev, 0, DEVCOUNT, "gio")) < 0) {
printk(KERN_ERR
"gio: Couldn't alloc_chrdev_region, error=%d\n",
error);
return 1;
}
cdev_p = cdev_alloc();
cdev_p->ops = &gio_fops;
error = cdev_add(cdev_p, dev, DEVCOUNT);
if (error) {
printk(KERN_ERR
"gio: Couldn't cdev_add, error=%d\n", error);
return 1;
}
return 0;
}
static void __exit gio_exit(void)
{
cdev_del(cdev_p);
unregister_chrdev_region(dev, DEVCOUNT);
}
module_init(gio_init);
module_exit(gio_exit);
MODULE_LICENSE("GPL");