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/* ------------------------------------------------------------------------- */
/* i2c-elv.c i2c-hw access for philips style parallel port adapters */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 1995-2000 Simon G. Vogl
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
Frodo Looijaard <frodol@dds.nl> */
/* $Id: i2c-elv.c,v 1.17 2001/07/29 02:44:25 mds Exp $ */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/version.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <linux/ioport.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#define DEFAULT_BASE 0x378
static int base=0;
static unsigned char PortData = 0;
/* ----- global defines ----------------------------------------------- */
#define DEB(x) /* should be reasonable open, close &c. */
#define DEB2(x) /* low level debugging - very slow */
#define DEBE(x) x /* error messages */
#define DEBINIT(x) x /* detection status messages */
/* --- Convenience defines for the parallel port: */
#define BASE (unsigned int)(data)
#define DATA BASE /* Centronics data port */
#define STAT (BASE+1) /* Centronics status port */
#define CTRL (BASE+2) /* Centronics control port */
/* ----- local functions ---------------------------------------------- */
static void bit_elv_setscl(void *data, int state)
{
if (state) {
PortData &= 0xfe;
} else {
PortData |=1;
}
outb(PortData, DATA);
}
static void bit_elv_setsda(void *data, int state)
{
if (state) {
PortData &=0xfd;
} else {
PortData |=2;
}
outb(PortData, DATA);
}
static int bit_elv_getscl(void *data)
{
return ( 0 == ( (inb_p(STAT)) & 0x08 ) );
}
static int bit_elv_getsda(void *data)
{
return ( 0 == ( (inb_p(STAT)) & 0x40 ) );
}
static int bit_elv_init(void)
{
if (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {
return -ENODEV;
} else {
/* test for ELV adap. */
if (inb(base+1) & 0x80) { /* BUSY should be high */
DEBINIT(printk("i2c-elv.o: Busy was low.\n"));
return -ENODEV;
} else {
outb(0x0c,base+2); /* SLCT auf low */
udelay(400);
if ( !(inb(base+1) && 0x10) ) {
outb(0x04,base+2);
DEBINIT(printk("i2c-elv.o: Select was high.\n"));
return -ENODEV;
}
}
request_region(base,(base == 0x3bc)? 3 : 8,
"i2c (ELV adapter)");
PortData = 0;
bit_elv_setsda((void*)base,1);
bit_elv_setscl((void*)base,1);
}
return 0;
}
static void __exit bit_elv_exit(void)
{
release_region( base , (base == 0x3bc)? 3 : 8 );
}
static int bit_elv_reg(struct i2c_client *client)
{
return 0;
}
static int bit_elv_unreg(struct i2c_client *client)
{
return 0;
}
static void bit_elv_inc_use(struct i2c_adapter *adap)
{
#ifdef MODULE
MOD_INC_USE_COUNT;
#endif
}
static void bit_elv_dec_use(struct i2c_adapter *adap)
{
#ifdef MODULE
MOD_DEC_USE_COUNT;
#endif
}
/* ------------------------------------------------------------------------
* Encapsulate the above functions in the correct operations structure.
* This is only done when more than one hardware adapter is supported.
*/
static struct i2c_algo_bit_data bit_elv_data = {
NULL,
bit_elv_setsda,
bit_elv_setscl,
bit_elv_getsda,
bit_elv_getscl,
80, 80, 100, /* waits, timeout */
};
static struct i2c_adapter bit_elv_ops = {
"ELV Parallel port adaptor",
I2C_HW_B_ELV,
NULL,
&bit_elv_data,
bit_elv_inc_use,
bit_elv_dec_use,
bit_elv_reg,
bit_elv_unreg,
};
int __init i2c_bitelv_init(void)
{
printk("i2c-elv.o: i2c ELV parallel port adapter module\n");
if (base==0) {
/* probe some values */
base=DEFAULT_BASE;
bit_elv_data.data=(void*)DEFAULT_BASE;
if (bit_elv_init()==0) {
if(i2c_bit_add_bus(&bit_elv_ops) < 0)
return -ENODEV;
} else {
return -ENODEV;
}
} else {
bit_elv_ops.data=(void*)base;
if (bit_elv_init()==0) {
if(i2c_bit_add_bus(&bit_elv_ops) < 0)
return -ENODEV;
} else {
return -ENODEV;
}
}
printk("i2c-elv.o: found device at %#x.\n",base);
return 0;
}
EXPORT_NO_SYMBOLS;
#ifdef MODULE
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus adapter routines for ELV parallel port adapter");
MODULE_LICENSE("GPL");
MODULE_PARM(base, "i");
int init_module(void)
{
return i2c_bitelv_init();
}
void cleanup_module(void)
{
i2c_bit_del_bus(&bit_elv_ops);
bit_elv_exit();
}
#endif
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