/**
 * @file me0900_di.c
 *
 * @brief ME-9x digital input subdevice instance.
 * @note Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
 * @author Guenter Gebhardt
 */

/*
 * Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
 *
 * This file 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.
 */

#ifndef __KERNEL__
#  define __KERNEL__
#endif

/*
 * Includes
 */
#include <linux/module.h>

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/version.h>

#include "medefines.h"
#include "meinternal.h"
#include "meerror.h"

#include "meids.h"
#include "medebug.h"
#include "meplx_reg.h"
#include "me0900_reg.h"
#include "me0900_di.h"

/*
 * Defines
 */

/*
 * Functions
 */

static int me0900_di_io_reset_subdevice(struct me_subdevice *subdevice,
                                        struct file *filep, int flags)
{
        PDEBUG("executed.\n");

        if (flags) {
                PERROR("Invalid flag specified.\n");
                return ME_ERRNO_INVALID_FLAGS;
        }

        return ME_ERRNO_SUCCESS;
}

static int me0900_di_io_single_config(me_subdevice_t * subdevice,
                                      struct file *filep,
                                      int channel,
                                      int single_config,
                                      int ref,
                                      int trig_chan,
                                      int trig_type, int trig_edge, int flags)
{
        me0900_di_subdevice_t *instance;
        int err = ME_ERRNO_SUCCESS;

        PDEBUG("executed.\n");

        instance = (me0900_di_subdevice_t *) subdevice;

        ME_SUBDEVICE_ENTER;

        spin_lock(&instance->subdevice_lock);
        switch (flags) {
        case ME_IO_SINGLE_CONFIG_NO_FLAGS:
        case ME_IO_SINGLE_TYPE_DIO_BYTE:
                if (channel == 0) {
                        if (single_config == ME_SINGLE_CONFIG_DIO_INPUT) {
                        } else {
                                PERROR("Invalid byte direction specified.\n");
                                err = ME_ERRNO_INVALID_SINGLE_CONFIG;
                        }
                } else {
                        PERROR("Invalid byte number specified.\n");
                        err = ME_ERRNO_INVALID_CHANNEL;
                }
                break;

        default:
                PERROR("Invalid flags specified.\n");
                err = ME_ERRNO_INVALID_FLAGS;
        }
        spin_unlock(&instance->subdevice_lock);

        ME_SUBDEVICE_EXIT;

        return err;
}

static int me0900_di_io_single_read(me_subdevice_t * subdevice,
                                    struct file *filep,
                                    int channel,
                                    int *value, int time_out, int flags)
{
        me0900_di_subdevice_t *instance;
        int err = ME_ERRNO_SUCCESS;

        PDEBUG("executed.\n");

        instance = (me0900_di_subdevice_t *) subdevice;

        ME_SUBDEVICE_ENTER;

        spin_lock(&instance->subdevice_lock);
        switch (flags) {
        case ME_IO_SINGLE_TYPE_DIO_BIT:
                if ((channel >= 0) && (channel < 8)) {
                        *value = (~inb(instance->port_reg)) & (0x1 << channel);
                } else {
                        PERROR("Invalid bit number specified.\n");
                        err = ME_ERRNO_INVALID_CHANNEL;
                }
                break;

        case ME_IO_SINGLE_NO_FLAGS:
        case ME_IO_SINGLE_TYPE_DIO_BYTE:
                if (channel == 0) {
                        *value = ~inb(instance->port_reg);
                } else {
                        PERROR("Invalid byte number specified.\n");
                        err = ME_ERRNO_INVALID_CHANNEL;
                }
                break;

        default:
                PERROR("Invalid flags specified.\n");
                err = ME_ERRNO_INVALID_FLAGS;
        }
        spin_unlock(&instance->subdevice_lock);

        ME_SUBDEVICE_EXIT;

        return err;
}

static int me0900_di_query_number_channels(me_subdevice_t * subdevice,
                                           int *number)
{
        PDEBUG("executed.\n");
        *number = 8;
        return ME_ERRNO_SUCCESS;
}

static int me0900_di_query_subdevice_type(me_subdevice_t * subdevice,
                                          int *type, int *subtype)
{
        PDEBUG("executed.\n");
        *type = ME_TYPE_DI;
        *subtype = ME_SUBTYPE_SINGLE;
        return ME_ERRNO_SUCCESS;
}

static int me0900_di_query_subdevice_caps(me_subdevice_t * subdevice, int *caps)
{
        PDEBUG("executed.\n");
        *caps = 0;
        return ME_ERRNO_SUCCESS;
}

me0900_di_subdevice_t *me0900_di_constructor(uint32_t reg_base,
                                             unsigned int di_idx)
{
        me0900_di_subdevice_t *subdevice;
        int err;

        PDEBUG("executed.\n");

        /* Allocate memory for subdevice instance */
        subdevice = kmalloc(sizeof(me0900_di_subdevice_t), GFP_KERNEL);

        if (!subdevice) {
                PERROR("Cannot get memory for subdevice instance.\n");
                return NULL;
        }

        memset(subdevice, 0, sizeof(me0900_di_subdevice_t));

        /* Initialize subdevice base class */
        err = me_subdevice_init(&subdevice->base);

        if (err) {
                PERROR("Cannot initialize subdevice base class instance.\n");
                kfree(subdevice);
                return NULL;
        }
        // Initialize spin locks.
        spin_lock_init(&subdevice->subdevice_lock);

        /* Save the subdevice index. */
        subdevice->di_idx = di_idx;

        /* Initialize registers */
        if (di_idx == 0) {
                subdevice->ctrl_reg = reg_base + ME0900_CTRL_REG;
                subdevice->port_reg = reg_base + ME0900_PORT_A_REG;
        } else {
                subdevice->ctrl_reg = reg_base + ME0900_CTRL_REG;
                subdevice->port_reg = reg_base + ME0900_PORT_B_REG;
        }
#ifdef MEDEBUG_DEBUG_REG
        subdevice->reg_base = reg_base;
#endif

        /* Overload base class methods. */
        subdevice->base.me_subdevice_io_reset_subdevice =
            me0900_di_io_reset_subdevice;
        subdevice->base.me_subdevice_io_single_config =
            me0900_di_io_single_config;
        subdevice->base.me_subdevice_io_single_read = me0900_di_io_single_read;
        subdevice->base.me_subdevice_query_number_channels =
            me0900_di_query_number_channels;
        subdevice->base.me_subdevice_query_subdevice_type =
            me0900_di_query_subdevice_type;
        subdevice->base.me_subdevice_query_subdevice_caps =
            me0900_di_query_subdevice_caps;

        return subdevice;
}