/* * Filename: ks0108.c * Version: 0.1.0 * Description: ks0108 LCD Controller driver * License: GPLv2 * Depends: parport * * Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com> * 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 <maxextreme@gmail.com>"); MODULE_DESCRIPTION("ks0108 LCD Controller driver");