/*
* Filename: ks0108.c
* Version: 0.1.0
* Description: ks0108 LCD Controller driver
* License: GPLv2
* Depends: parport
*
* Author: Copyright (C) Miguel Ojeda Sandonis
* Date: 2006-10-31
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/parport.h>
#include <linux/uaccess.h>
#include <linux/ks0108.h>
#define KS0108_NAME "ks0108"
/*
* Module Parameters
*/
static unsigned int ks0108_port = CONFIG_KS0108_PORT;
module_param(ks0108_port, uint, S_IRUGO);
MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
module_param(ks0108_delay, uint, S_IRUGO);
MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
/*
* Device
*/
static struct parport *ks0108_parport;
static struct pardevice *ks0108_pardevice;
/*
* ks0108 Exported Commands (don't lock)
*
* You _should_ lock in the top driver: This functions _should not_
* get race conditions in any way. Locking for each byte here would be
* so slow and useless.
*
* There are not bit definitions because they are not flags,
* just arbitrary combinations defined by the documentation for each
* function in the ks0108 LCD controller. If you want to know what means
* a specific combination, look at the function's name.
*
* The ks0108_writecontrol bits need to be reverted ^(0,1,3) because
* the parallel port also revert them using a "not" logic gate.
*/
#define bit(n) (((unsigned char)1)<<(n))
void ks0108_writedata(unsigned char byte)
{
parport_write_data(ks0108_parport, byte);
}
void ks0108_writecontrol(unsigned char byte)
{
udelay(ks0108_delay);
parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
}
void ks0108_displaystate(unsigned char state)
{
ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5));
}
void ks0108_startline(unsigned char startline)
{
ks0108_writedata(min(startline,(unsigned char)63) | bit(6) | bit(7));
}
void ks0108_address(unsigned char address)
{
ks0108_writedata(min(address,(unsigned char)63) | bit(6));
}
void ks0108_page(unsigned char page)
{
ks0108_writedata(min(page,(unsigned char)7) | bit(3) | bit(4) | bit(5) | bit(7));
}
EXPORT_SYMBOL_GPL(ks0108_writedata);
EXPORT_SYMBOL_GPL(ks0108_writecontrol);
EXPORT_SYMBOL_GPL(ks0108_displaystate);
EXPORT_SYMBOL_GPL(ks0108_startline);
EXPORT_SYMBOL_GPL(ks0108_address);
EXPORT_SYMBOL_GPL(ks0108_page);
/*
* Is the module inited?
*/
static unsigned char ks0108_inited;
unsigned char ks0108_isinited(void)
{
return ks0108_inited;
}
EXPORT_SYMBOL_GPL(ks0108_isinited);
/*
* Module Init & Exit
*/
static int __init ks0108_init(void)
{
int result;
int ret = -EINVAL;
ks0108_parport = parport_find_base(ks0108_port);
if (ks0108_parport == NULL) {
printk(KERN_ERR KS0108_NAME ": ERROR: "
"parport didn't find %i port\n", ks0108_port);
goto none;
}
ks0108_pardevice = parport_register_device(ks0108_parport, KS0108_NAME,
NULL, NULL, NULL, PARPORT_DEV_EXCL, NULL);
if (ks0108_pardevice == NULL) {
printk(KERN_ERR KS0108_NAME ": ERROR: "
"parport didn't register new device\n");
goto none;
}
result = parport_claim(ks0108_pardevice);
if (result != 0) {
printk(KERN_ERR KS0108_NAME ": ERROR: "
"can't claim %i parport, maybe in use\n", ks0108_port);
ret = result;
goto registered;
}
ks0108_inited = 1;
return 0;
registered:
parport_unregister_device(ks0108_pardevice);
none:
return ret;
}
static void __exit ks0108_exit(void)
{
parport_release(ks0108_pardevice);
parport_unregister_device(ks0108_pardevice);
}
module_init(ks0108_init);
module_exit(ks0108_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>");
MODULE_DESCRIPTION("ks0108 LCD Controller driver");
