/*
    comedi/drivers/ssv_dnp.c
    generic comedi driver for SSV Embedded Systems' DIL/Net-PCs
    Copyright (C) 2001 Robert Schwebel <robert@schwebel.de>

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 2000 David A. Schleef <ds@schleef.org>

    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.

*/
/*
Driver: ssv_dnp
Description: SSV Embedded Systems DIL/Net-PC
Author: Robert Schwebel <robert@schwebel.de>
Devices: [SSV Embedded Systems] DIL/Net-PC 1486 (dnp-1486)
Status: unknown
*/

/* include files ----------------------------------------------------------- */

#include "../comedidev.h"

/* Some global definitions: the registers of the DNP ----------------------- */
/*                                                                           */
/* For port A and B the mode register has bits corresponding to the output   */
/* pins, where Bit-N = 0 -> input, Bit-N = 1 -> output. Note that bits       */
/* 4 to 7 correspond to pin 0..3 for port C data register. Ensure that bits  */
/* 0..3 remain unchanged! For details about Port C Mode Register see         */
/* the remarks in dnp_insn_config() below.                                   */

#define CSCIR 0x22              /* Chip Setup and Control Index Register     */
#define CSCDR 0x23              /* Chip Setup and Control Data Register      */
#define PAMR  0xa5              /* Port A Mode Register                      */
#define PADR  0xa9              /* Port A Data Register                      */
#define PBMR  0xa4              /* Port B Mode Register                      */
#define PBDR  0xa8              /* Port B Data Register                      */
#define PCMR  0xa3              /* Port C Mode Register                      */
#define PCDR  0xa7              /* Port C Data Register                      */

/* This data structure holds information about the supported boards -------- */

struct dnp_board {
        const char *name;
        int ai_chans;
        int ai_bits;
        int have_dio;
};

/* ------------------------------------------------------------------------- */
/* The insn_bits interface allows packed reading/writing of DIO channels.    */
/* The comedi core can convert between insn_bits and insn_read/write, so you */
/* are able to use these instructions as well.                               */
/* ------------------------------------------------------------------------- */

static int dnp_dio_insn_bits(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn, unsigned int *data)
{
        /* The insn data is a mask in data[0] and the new data in data[1],   */
        /* each channel cooresponding to a bit.                              */

        /* Ports A and B are straight forward: each bit corresponds to an    */
        /* output pin with the same order. Port C is different: bits 0...3   */
        /* correspond to bits 4...7 of the output register (PCDR).           */

        if (data[0]) {

                outb(PADR, CSCIR);
                outb((inb(CSCDR)
                      & ~(u8) (data[0] & 0x0000FF))
                     | (u8) (data[1] & 0x0000FF), CSCDR);

                outb(PBDR, CSCIR);
                outb((inb(CSCDR)
                      & ~(u8) ((data[0] & 0x00FF00) >> 8))
                     | (u8) ((data[1] & 0x00FF00) >> 8), CSCDR);

                outb(PCDR, CSCIR);
                outb((inb(CSCDR)
                      & ~(u8) ((data[0] & 0x0F0000) >> 12))
                     | (u8) ((data[1] & 0x0F0000) >> 12), CSCDR);
        }

        /* on return, data[1] contains the value of the digital input lines. */
        outb(PADR, CSCIR);
        data[0] = inb(CSCDR);
        outb(PBDR, CSCIR);
        data[0] += inb(CSCDR) << 8;
        outb(PCDR, CSCIR);
        data[0] += ((inb(CSCDR) & 0xF0) << 12);

        return insn->n;

}

/* ------------------------------------------------------------------------- */
/* Configure the direction of the bidirectional digital i/o pins. chanspec   */
/* contains the channel to be changed and data[0] contains either            */
/* COMEDI_INPUT or COMEDI_OUTPUT.                                            */
/* ------------------------------------------------------------------------- */

static int dnp_dio_insn_config(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn, unsigned int *data)
{

        u8 register_buffer;

        /* reduces chanspec to lower 16 bits */
        int chan = CR_CHAN(insn->chanspec);

        switch (data[0]) {
        case INSN_CONFIG_DIO_OUTPUT:
        case INSN_CONFIG_DIO_INPUT:
                break;
        case INSN_CONFIG_DIO_QUERY:
                data[1] =
                    (inb(CSCDR) & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT;
                return insn->n;
                break;
        default:
                return -EINVAL;
                break;
        }
        /* Test: which port does the channel belong to?                       */

        /* We have to pay attention with port C: this is the meaning of PCMR: */
        /* Bit in PCMR:              7 6 5 4 3 2 1 0                          */
        /* Corresponding port C pin: d 3 d 2 d 1 d 0   d= don't touch         */

        if ((chan >= 0) && (chan <= 7)) {
                /* this is port A */
                outb(PAMR, CSCIR);
        } else if ((chan >= 8) && (chan <= 15)) {
                /* this is port B */
                chan -= 8;
                outb(PBMR, CSCIR);
        } else if ((chan >= 16) && (chan <= 19)) {
                /* this is port C; multiplication with 2 brings bits into     */
                /* correct position for PCMR!                                 */
                chan -= 16;
                chan *= 2;
                outb(PCMR, CSCIR);
        } else {
                return -EINVAL;
        }

        /* read 'old' direction of the port and set bits (out=1, in=0)        */
        register_buffer = inb(CSCDR);
        if (data[0] == COMEDI_OUTPUT)
                register_buffer |= (1 << chan);
        else
                register_buffer &= ~(1 << chan);

        outb(register_buffer, CSCDR);

        return 1;

}

static int dnp_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
        const struct dnp_board *board = comedi_board(dev);
        struct comedi_subdevice *s;
        int ret;

        dev->board_name = board->name;

        ret = comedi_alloc_subdevices(dev, 1);
        if (ret)
                return ret;

        s = &dev->subdevices[0];
        /* digital i/o subdevice                                             */
        s->type = COMEDI_SUBD_DIO;
        s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
        s->n_chan = 20;
        s->maxdata = 1;
        s->range_table = &range_digital;
        s->insn_bits = dnp_dio_insn_bits;
        s->insn_config = dnp_dio_insn_config;

        /* We use the I/O ports 0x22,0x23 and 0xa3-0xa9, which are always
         * allocated for the primary 8259, so we don't need to allocate them
         * ourselves. */

        /* configure all ports as input (default)                            */
        outb(PAMR, CSCIR);
        outb(0x00, CSCDR);
        outb(PBMR, CSCIR);
        outb(0x00, CSCDR);
        outb(PCMR, CSCIR);
        outb((inb(CSCDR) & 0xAA), CSCDR);

        dev_info(dev->class_dev, "%s: attached\n", dev->board_name);
        return 1;
}

static void dnp_detach(struct comedi_device *dev)
{
        outb(PAMR, CSCIR);
        outb(0x00, CSCDR);
        outb(PBMR, CSCIR);
        outb(0x00, CSCDR);
        outb(PCMR, CSCIR);
        outb((inb(CSCDR) & 0xAA), CSCDR);
}

static const struct dnp_board dnp_boards[] = {
        {
                .name           = "dnp-1486",
                .ai_chans       = 16,
                .ai_bits        = 12,
                .have_dio       = 1,
        },
};

static struct comedi_driver dnp_driver = {
        .driver_name    = "ssv_dnp",
        .module         = THIS_MODULE,
        .attach         = dnp_attach,
        .detach         = dnp_detach,
        .board_name     = &dnp_boards[0].name,
        .offset         = sizeof(struct dnp_board),
        .num_names      = ARRAY_SIZE(dnp_boards),
};
module_comedi_driver(dnp_driver);

MODULE_AUTHOR("Comedi http://www.comedi.org");
MODULE_DESCRIPTION("Comedi low-level driver");
MODULE_LICENSE("GPL");