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Diffstat (limited to 'drivers/auxdisplay/ks0108.c')
-rw-r--r--drivers/auxdisplay/ks0108.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/auxdisplay/ks0108.c b/drivers/auxdisplay/ks0108.c
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--- /dev/null
+++ b/drivers/auxdisplay/ks0108.c
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+/*
+ * 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");
+