linux/drivers/macintosh/ans-lcd.c
Arjan van de Ven fa027c2a0a [PATCH] mark struct file_operations const 4
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@sdl.org: dvb fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00

186 lines
3.7 KiB
C

/*
* /dev/lcd driver for Apple Network Servers.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/ans-lcd.h>
#include <asm/io.h>
#define ANSLCD_ADDR 0xf301c000
#define ANSLCD_CTRL_IX 0x00
#define ANSLCD_DATA_IX 0x10
static unsigned long anslcd_short_delay = 80;
static unsigned long anslcd_long_delay = 3280;
static volatile unsigned char __iomem *anslcd_ptr;
#undef DEBUG
static void
anslcd_write_byte_ctrl ( unsigned char c )
{
#ifdef DEBUG
printk(KERN_DEBUG "LCD: CTRL byte: %02x\n",c);
#endif
out_8(anslcd_ptr + ANSLCD_CTRL_IX, c);
switch(c) {
case 1:
case 2:
case 3:
udelay(anslcd_long_delay); break;
default: udelay(anslcd_short_delay);
}
}
static void
anslcd_write_byte_data ( unsigned char c )
{
out_8(anslcd_ptr + ANSLCD_DATA_IX, c);
udelay(anslcd_short_delay);
}
static ssize_t
anslcd_write( struct file * file, const char __user * buf,
size_t count, loff_t *ppos )
{
const char __user *p = buf;
int i;
#ifdef DEBUG
printk(KERN_DEBUG "LCD: write\n");
#endif
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
for ( i = *ppos; count > 0; ++i, ++p, --count )
{
char c;
__get_user(c, p);
anslcd_write_byte_data( c );
}
*ppos = i;
return p - buf;
}
static int
anslcd_ioctl( struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg )
{
char ch, __user *temp;
#ifdef DEBUG
printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg);
#endif
switch ( cmd )
{
case ANSLCD_CLEAR:
anslcd_write_byte_ctrl ( 0x38 );
anslcd_write_byte_ctrl ( 0x0f );
anslcd_write_byte_ctrl ( 0x06 );
anslcd_write_byte_ctrl ( 0x01 );
anslcd_write_byte_ctrl ( 0x02 );
return 0;
case ANSLCD_SENDCTRL:
temp = (char __user *) arg;
__get_user(ch, temp);
for (; ch; temp++) { /* FIXME: This is ugly, but should work, as a \0 byte is not a valid command code */
anslcd_write_byte_ctrl ( ch );
__get_user(ch, temp);
}
return 0;
case ANSLCD_SETSHORTDELAY:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
anslcd_short_delay=arg;
return 0;
case ANSLCD_SETLONGDELAY:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
anslcd_long_delay=arg;
return 0;
default:
return -EINVAL;
}
}
static int
anslcd_open( struct inode * inode, struct file * file )
{
return 0;
}
const struct file_operations anslcd_fops = {
.write = anslcd_write,
.ioctl = anslcd_ioctl,
.open = anslcd_open,
};
static struct miscdevice anslcd_dev = {
ANSLCD_MINOR,
"anslcd",
&anslcd_fops
};
const char anslcd_logo[] = "********************" /* Line #1 */
"* LINUX! *" /* Line #3 */
"* Welcome to *" /* Line #2 */
"********************"; /* Line #4 */
static int __init
anslcd_init(void)
{
int a;
int retval;
struct device_node* node;
node = find_devices("lcd");
if (!node || !node->parent)
return -ENODEV;
if (strcmp(node->parent->name, "gc"))
return -ENODEV;
anslcd_ptr = ioremap(ANSLCD_ADDR, 0x20);
retval = misc_register(&anslcd_dev);
if(retval < 0){
printk(KERN_INFO "LCD: misc_register failed\n");
iounmap(anslcd_ptr);
return retval;
}
#ifdef DEBUG
printk(KERN_DEBUG "LCD: init\n");
#endif
anslcd_write_byte_ctrl ( 0x38 );
anslcd_write_byte_ctrl ( 0x0c );
anslcd_write_byte_ctrl ( 0x06 );
anslcd_write_byte_ctrl ( 0x01 );
anslcd_write_byte_ctrl ( 0x02 );
for(a=0;a<80;a++) {
anslcd_write_byte_data(anslcd_logo[a]);
}
return 0;
}
static void __exit
anslcd_exit(void)
{
misc_deregister(&anslcd_dev);
iounmap(anslcd_ptr);
}
module_init(anslcd_init);
module_exit(anslcd_exit);