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/* ------------------------------------------------------------------------- */
/* i2c-philips-par.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-philips-par.c,v 1.18 2000/07/06 19:21:49 frodo Exp $ */
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/stddef.h>
#include <linux/parport.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#ifndef __exit
#define __exit __init
#endif
static int type;
struct i2c_par
{
struct pardevice *pdev;
struct i2c_adapter adapter;
struct i2c_algo_bit_data bit_lp_data;
struct i2c_par *next;
};
static struct i2c_par *adapter_list;
/* ----- 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 */
/* ----- printer port defines ------------------------------------------*/
/* Pin Port Inverted name */
#define I2C_ON 0x20 /* 12 status N paper */
/* ... only for phil. not used */
#define I2C_SDA 0x80 /* 9 data N data7 */
#define I2C_SCL 0x08 /* 17 ctrl N dsel */
#define I2C_SDAIN 0x80 /* 11 stat Y busy */
#define I2C_SCLIN 0x08 /* 15 stat Y enable */
#define I2C_DMASK 0x7f
#define I2C_CMASK 0xf7
/* ----- local functions ---------------------------------------------- */
static void bit_lp_setscl(void *data, int state)
{
/*be cautious about state of the control register -
touch only the one bit needed*/
if (state) {
parport_write_control((struct parport *) data,
parport_read_control((struct parport *) data)|I2C_SCL);
} else {
parport_write_control((struct parport *) data,
parport_read_control((struct parport *) data)&I2C_CMASK);
}
}
static void bit_lp_setsda(void *data, int state)
{
if (state) {
parport_write_data((struct parport *) data, I2C_DMASK);
} else {
parport_write_data((struct parport *) data, I2C_SDA);
}
}
static int bit_lp_getscl(void *data)
{
return parport_read_status((struct parport *) data) & I2C_SCLIN;
}
static int bit_lp_getsda(void *data)
{
return parport_read_status((struct parport *) data) & I2C_SDAIN;
}
static void bit_lp_setscl2(void *data, int state)
{
if (state) {
parport_write_data((struct parport *) data,
parport_read_data((struct parport *) data)|0x1);
} else {
parport_write_data((struct parport *) data,
parport_read_data((struct parport *) data)&0xfe);
}
}
static void bit_lp_setsda2(void *data, int state)
{
if (state) {
parport_write_data((struct parport *) data,
parport_read_data((struct parport *) data)|0x2);
} else {
parport_write_data((struct parport *) data,
parport_read_data((struct parport *) data)&0xfd);
}
}
static int bit_lp_getsda2(void *data)
{
return (parport_read_status((struct parport *) data) &
PARPORT_STATUS_BUSY) ? 0 : 1;
}
static int bit_lp_reg(struct i2c_client *client)
{
return 0;
}
static int bit_lp_unreg(struct i2c_client *client)
{
return 0;
}
static void bit_lp_inc_use(struct i2c_adapter *adap)
{
MOD_INC_USE_COUNT;
}
static void bit_lp_dec_use(struct i2c_adapter *adap)
{
MOD_DEC_USE_COUNT;
}
/* ------------------------------------------------------------------------
* 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_lp_data = {
NULL,
bit_lp_setsda,
bit_lp_setscl,
bit_lp_getsda,
bit_lp_getscl,
80, 80, 100, /* waits, timeout */
};
static struct i2c_algo_bit_data bit_lp_data2 = {
NULL,
bit_lp_setsda2,
bit_lp_setscl2,
bit_lp_getsda2,
NULL,
80, 80, 100, /* waits, timeout */
};
static struct i2c_adapter bit_lp_ops = {
"Philips Parallel port adapter",
I2C_HW_B_LP,
NULL,
NULL,
bit_lp_inc_use,
bit_lp_dec_use,
bit_lp_reg,
bit_lp_unreg,
};
static void i2c_parport_attach (struct parport *port)
{
struct i2c_par *adapter = kmalloc(sizeof(struct i2c_par),
GFP_KERNEL);
if (!adapter) {
printk("i2c-philips-par: Unable to malloc.\n");
return;
}
printk("i2c-philips-par.o: attaching to %s\n", port->name);
adapter->pdev = parport_register_device(port, "i2c-philips-par",
NULL, NULL, NULL,
PARPORT_FLAG_EXCL,
NULL);
if (!adapter->pdev) {
printk("i2c-philips-par: Unable to register with parport.\n");
return;
}
adapter->adapter = bit_lp_ops;
adapter->adapter.algo_data = &adapter->bit_lp_data;
adapter->bit_lp_data = type ? bit_lp_data2 : bit_lp_data;
adapter->bit_lp_data.data = port;
/* reset hardware to sane state */
parport_claim_or_block(adapter->pdev);
bit_lp_setsda(port, 1);
bit_lp_setscl(port, 1);
parport_release(adapter->pdev);
if (i2c_bit_add_bus(&adapter->adapter) < 0)
{
printk("i2c-philips-par: Unable to register with I2C.\n");
parport_unregister_device(adapter->pdev);
kfree(adapter);
return; /* No good */
}
adapter->next = adapter_list;
adapter_list = adapter;
}
static void i2c_parport_detach (struct parport *port)
{
struct i2c_par *adapter, *prev = NULL;
for (adapter = adapter_list; adapter; adapter = adapter->next)
{
if (adapter->pdev->port == port)
{
parport_unregister_device(adapter->pdev);
i2c_bit_del_bus(&adapter->adapter);
if (prev)
prev->next = adapter->next;
else
adapter_list = adapter->next;
kfree(adapter);
return;
}
prev = adapter;
}
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,4)
static struct parport_driver i2c_driver = {
"i2c-philips-par",
i2c_parport_attach,
i2c_parport_detach,
NULL
};
#endif
int __init i2c_bitlp_init(void)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,4)
struct parport *port;
#endif
printk("i2c-philips-par.o: i2c Philips parallel port adapter module\n");
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,4)
parport_register_driver(&i2c_driver);
#else
for (port = parport_enumerate(); port; port=port->next)
i2c_parport_attach(port);
#endif
return 0;
}
void __exit i2c_bitlp_exit(void)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,4)
parport_unregister_driver(&i2c_driver);
#else
struct parport *port;
for (port = parport_enumerate(); port; port=port->next)
i2c_parport_detach(port);
#endif
}
EXPORT_NO_SYMBOLS;
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus adapter routines for Philips parallel port adapter");
MODULE_LICENSE("GPL");
MODULE_PARM(type, "i");
#ifdef MODULE
int init_module(void)
{
return i2c_bitlp_init();
}
void cleanup_module(void)
{
i2c_bitlp_exit();
}
#endif
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