swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 2c85ebc57b3e1817b6ce1a6b703928e113a90442 authored by Linus Torvalds on 13 December 2020, 22:41:30 UTC
Linux 5.10
Linux 5.10
Tip revision: 2c85ebc
ans-lcd.c
// SPDX-License-Identifier: GPL-2.0
/*
* /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/module.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/io.h>
#include "ans-lcd.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;
static DEFINE_MUTEX(anslcd_mutex);
#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(buf, count))
return -EFAULT;
mutex_lock(&anslcd_mutex);
for ( i = *ppos; count > 0; ++i, ++p, --count )
{
char c;
__get_user(c, p);
anslcd_write_byte_data( c );
}
mutex_unlock(&anslcd_mutex);
*ppos = i;
return p - buf;
}
static long
anslcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
char ch, __user *temp;
long ret = 0;
#ifdef DEBUG
printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg);
#endif
mutex_lock(&anslcd_mutex);
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 );
break;
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);
}
break;
case ANSLCD_SETSHORTDELAY:
if (!capable(CAP_SYS_ADMIN))
ret =-EACCES;
else
anslcd_short_delay=arg;
break;
case ANSLCD_SETLONGDELAY:
if (!capable(CAP_SYS_ADMIN))
ret = -EACCES;
else
anslcd_long_delay=arg;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&anslcd_mutex);
return ret;
}
static int
anslcd_open( struct inode * inode, struct file * file )
{
return 0;
}
const struct file_operations anslcd_fops = {
.write = anslcd_write,
.unlocked_ioctl = anslcd_ioctl,
.open = anslcd_open,
.llseek = default_llseek,
};
static struct miscdevice anslcd_dev = {
LCD_MINOR,
"anslcd",
&anslcd_fops
};
static const char anslcd_logo[] __initconst =
"********************" /* 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 = of_find_node_by_name(NULL, "lcd");
if (!node || !of_node_name_eq(node->parent, "gc")) {
of_node_put(node);
return -ENODEV;
}
of_node_put(node);
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
mutex_lock(&anslcd_mutex);
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]);
}
mutex_unlock(&anslcd_mutex);
return 0;
}
static void __exit
anslcd_exit(void)
{
misc_deregister(&anslcd_dev);
iounmap(anslcd_ptr);
}
module_init(anslcd_init);
module_exit(anslcd_exit);
MODULE_LICENSE("GPL v2");