linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 *    Filename: ks0108.c

 *     Version: 0.1.0

 * Description: ks0108 LCD Controller driver

 *     Depends: parport

 *

 *      Author: Copyright (C) Miguel Ojeda Sandonis

 *        Date: 2006-10-31

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#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)