archived-lcd4linux/drv_generic_i2c.c

/* $Id: drv_generic_i2c.c,v 1.3 2005/05/08 04:32:44 reinelt Exp $
 *
 * generic driver helper for i2c displays
 *
 * Copyright (C) 2005 Luis F. Correia <luis.f.correia@seg-social.pt>
 * Copyright (C) 2005 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux 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, or (at your option)
 * any later version.
 *
 * LCD4Linux 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.
 *
 *
 * $Log: drv_generic_i2c.c,v $
 * Revision 1.3  2005/05/08 04:32:44  reinelt
 * CodingStyle added and applied
 *
 * Revision 1.2  2005/04/05 05:12:57  reinelt
 * i2c patch from Paul (still does not work here :-(
 *
 * Revision 1.1  2005/03/28 19:39:23  reinelt
 * HD44780/I2C patch from Luis merged (still does not work for me)
 *
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
#include <time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#include <linux/compiler.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>

#include "debug.h"
#include "qprintf.h"
#include "cfg.h"
#include "udelay.h"
#include "drv_generic_i2c.h"

static char *Driver = "";
static char *Section = "";
static int i2c_device;

static void my_i2c_smbus_write_byte_data(const int device, const unsigned char data)
{
    struct i2c_smbus_ioctl_data args;
    args.read_write = I2C_SMBUS_WRITE;
    args.command = data;
    args.size = I2C_SMBUS_BYTE;
    args.data = 0;
    ioctl(device, I2C_SMBUS, &args);
}

static void my_i2c_smbus_read_byte_data(const int device, const unsigned char data)
{
    struct i2c_smbus_ioctl_data args;
    args.read_write = I2C_SMBUS_READ;
    args.command = data;
    args.size = I2C_SMBUS_BYTE;
    args.data = 0;
    ioctl(device, I2C_SMBUS, &args);
}

int drv_generic_i2c_open(const char *section, const char *driver)
{
    int dev;
    char *bus, *device;

    //SIGNAL_ENABLE = 0x40;
    //SIGNAL_RW = 0x10;
    //SIGNAL_RS = 0x20;

    udelay_init();

    Section = (char *) section;
    Driver = (char *) driver;

    bus = cfg_get(Section, "Port", NULL);
    device = cfg_get(Section, "Device", NULL);
    dev = atoi(device);
    info("%s: initializing I2C bus %s", Driver, bus);
    info("device %d", dev);
    if ((i2c_device = open(bus, O_WRONLY)) < 0) {
	error("%s: I2C bus %s open failed !\n", Driver, bus);
	return -1;
    }

    info("%s: initializing I2C slave device 0x%x", Driver, dev);
    if (ioctl(i2c_device, I2C_SLAVE, dev) < 0) {
	error("%s: error initializing device 0x%x\n", Driver, dev);
	close(i2c_device);
	return -1;
    }

    return 0;
}


int drv_generic_i2c_close(void)
{

    close(i2c_device);

    return 0;
}

unsigned char drv_generic_i2c_wire(const char *name, const char *deflt)
{
    unsigned char w;
    char wire[256];
    char *s;

    qprintf(wire, sizeof(wire), "Wire.%s", name);
    s = cfg_get(Section, wire, deflt);
    if (strlen(s) == 3 && strncasecmp(s, "DB", 2) == 0 && s[2] >= '0' && s[2] <= '7') {
	w = s[2] - '0';
    } else if (strcasecmp(s, "GND") == 0) {
	w = 0;
    } else {
	error("%s: unknown signal <%s> for wire <%s>", Driver, s, name);
	error("%s: should be DB0..7 or GND", Driver);
	return 0xff;
    }
    free(s);
    if (w == 0) {
	info("%s: wiring: [DISPLAY:%s]<==>[i2c:GND]", Driver, name);
    } else {
	info("%s: wiring: [DISPLAY:%s]<==>[i2c:DB%d]", Driver, name, w);
    }

    w = 1 << w;

    return w;
}

void drv_generic_i2c_data(const unsigned char data)
{

    my_i2c_smbus_write_byte_data(i2c_device, data);

}