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