diff options
Diffstat (limited to 'drivers/auxdisplay/ks0108.c')
| -rw-r--r-- | drivers/auxdisplay/ks0108.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/auxdisplay/ks0108.c b/drivers/auxdisplay/ks0108.c new file mode 100644 index 0000000..a637575 --- /dev/null +++ b/drivers/auxdisplay/ks0108.c @@ -0,0 +1,166 @@ +/* + * 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); + +/* + * 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; + } + + 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"); + |