// SPDX-License-Identifier: GPL-2.0+
/*
 * comedi/drivers/dt2817.c
 * Hardware driver for Data Translation DT2817
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
 */
/*
 * Driver: dt2817
 * Description: Data Translation DT2817
 * Author: ds
 * Status: complete
 * Devices: [Data Translation] DT2817 (dt2817)
 *
 * A very simple digital I/O card.  Four banks of 8 lines, each bank
 * is configurable for input or output.  One wonders why it takes a
 * 50 page manual to describe this thing.
 *
 * The driver (which, btw, is much less than 50 pages) has 1 subdevice
 * with 32 channels, configurable in groups of 8.
 *
 * Configuration options:
 * [0] - I/O port base base address
 */

#include <linux/module.h>
#include <linux/comedi/comedidev.h>

#define DT2817_CR 0
#define DT2817_DATA 1

static int dt2817_dio_insn_config(struct comedi_device *dev,
                                  struct comedi_subdevice *s,
                                  struct comedi_insn *insn,
                                  unsigned int *data)
{
        unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int oe = 0;
        unsigned int mask;
        int ret;

        if (chan < 8)
                mask = 0x000000ff;
        else if (chan < 16)
                mask = 0x0000ff00;
        else if (chan < 24)
                mask = 0x00ff0000;
        else
                mask = 0xff000000;

        ret = comedi_dio_insn_config(dev, s, insn, data, mask);
        if (ret)
                return ret;

        if (s->io_bits & 0x000000ff)
                oe |= 0x1;
        if (s->io_bits & 0x0000ff00)
                oe |= 0x2;
        if (s->io_bits & 0x00ff0000)
                oe |= 0x4;
        if (s->io_bits & 0xff000000)
                oe |= 0x8;

        outb(oe, dev->iobase + DT2817_CR);

        return insn->n;
}

static int dt2817_dio_insn_bits(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_insn *insn,
                                unsigned int *data)
{
        unsigned long iobase = dev->iobase + DT2817_DATA;
        unsigned int mask;
        unsigned int val;

        mask = comedi_dio_update_state(s, data);
        if (mask) {
                if (mask & 0x000000ff)
                        outb(s->state & 0xff, iobase + 0);
                if (mask & 0x0000ff00)
                        outb((s->state >> 8) & 0xff, iobase + 1);
                if (mask & 0x00ff0000)
                        outb((s->state >> 16) & 0xff, iobase + 2);
                if (mask & 0xff000000)
                        outb((s->state >> 24) & 0xff, iobase + 3);
        }

        val = inb(iobase + 0);
        val |= (inb(iobase + 1) << 8);
        val |= (inb(iobase + 2) << 16);
        val |= (inb(iobase + 3) << 24);

        data[1] = val;

        return insn->n;
}

static int dt2817_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
        int ret;
        struct comedi_subdevice *s;

        ret = comedi_request_region(dev, it->options[0], 0x5);
        if (ret)
                return ret;

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

        s = &dev->subdevices[0];

        s->n_chan = 32;
        s->type = COMEDI_SUBD_DIO;
        s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
        s->range_table = &range_digital;
        s->maxdata = 1;
        s->insn_bits = dt2817_dio_insn_bits;
        s->insn_config = dt2817_dio_insn_config;

        s->state = 0;
        outb(0, dev->iobase + DT2817_CR);

        return 0;
}

static struct comedi_driver dt2817_driver = {
        .driver_name    = "dt2817",
        .module         = THIS_MODULE,
        .attach         = dt2817_attach,
        .detach         = comedi_legacy_detach,
};
module_comedi_driver(dt2817_driver);

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