// SPDX-License-Identifier: GPL-2.0+
/*
 * pcmda12.c
 * Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board.
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 2006 Calin A. Culianu <calin@ajvar.org>
 */

/*
 * Driver: pcmda12
 * Description: A driver for the Winsystems PCM-D/A-12
 * Devices: [Winsystems] PCM-D/A-12 (pcmda12)
 * Author: Calin Culianu <calin@ajvar.org>
 * Updated: Fri, 13 Jan 2006 12:01:01 -0500
 * Status: works
 *
 * A driver for the relatively straightforward-to-program PCM-D/A-12.
 * This board doesn't support commands, and the only way to set its
 * analog output range is to jumper the board. As such,
 * comedi_data_write() ignores the range value specified.
 *
 * The board uses 16 consecutive I/O addresses starting at the I/O port
 * base address. Each address corresponds to the LSB then MSB of a
 * particular channel from 0-7.
 *
 * Note that the board is not ISA-PNP capable and thus needs the I/O
 * port comedi_config parameter.
 *
 * Note that passing a nonzero value as the second config option will
 * enable "simultaneous xfer" mode for this board, in which AO writes
 * will not take effect until a subsequent read of any AO channel. This
 * is so that one can speed up programming by preloading all AO registers
 * with values before simultaneously setting them to take effect with one
 * read command.
 *
 * Configuration Options:
 *   [0] - I/O port base address
 *   [1] - Do Simultaneous Xfer (see description)
 */

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

/* AI range is not configurable, it's set by jumpers on the board */
static const struct comedi_lrange pcmda12_ranges = {
        3, {
                UNI_RANGE(5),
                UNI_RANGE(10),
                BIP_RANGE(5)
        }
};

struct pcmda12_private {
        int simultaneous_xfer_mode;
};

static int pcmda12_ao_insn_write(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 struct comedi_insn *insn,
                                 unsigned int *data)
{
        struct pcmda12_private *devpriv = dev->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int val = s->readback[chan];
        unsigned long ioreg = dev->iobase + (chan * 2);
        int i;

        for (i = 0; i < insn->n; ++i) {
                val = data[i];
                outb(val & 0xff, ioreg);
                outb((val >> 8) & 0xff, ioreg + 1);

                /*
                 * Initiate transfer if not in simultaneaous xfer
                 * mode by reading one of the AO registers.
                 */
                if (!devpriv->simultaneous_xfer_mode)
                        inb(ioreg);
        }
        s->readback[chan] = val;

        return insn->n;
}

static int pcmda12_ao_insn_read(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_insn *insn,
                                unsigned int *data)
{
        struct pcmda12_private *devpriv = dev->private;

        /*
         * Initiate simultaneaous xfer mode by reading one of the
         * AO registers. All analog outputs will then be updated.
         */
        if (devpriv->simultaneous_xfer_mode)
                inb(dev->iobase);

        return comedi_readback_insn_read(dev, s, insn, data);
}

static void pcmda12_ao_reset(struct comedi_device *dev,
                             struct comedi_subdevice *s)
{
        int i;

        for (i = 0; i < s->n_chan; ++i) {
                outb(0, dev->iobase + (i * 2));
                outb(0, dev->iobase + (i * 2) + 1);
        }
        /* Initiate transfer by reading one of the AO registers. */
        inb(dev->iobase);
}

static int pcmda12_attach(struct comedi_device *dev,
                          struct comedi_devconfig *it)
{
        struct pcmda12_private *devpriv;
        struct comedi_subdevice *s;
        int ret;

        ret = comedi_request_region(dev, it->options[0], 0x10);
        if (ret)
                return ret;

        devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
        if (!devpriv)
                return -ENOMEM;

        devpriv->simultaneous_xfer_mode = it->options[1];

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

        s = &dev->subdevices[0];
        s->type         = COMEDI_SUBD_AO;
        s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
        s->n_chan       = 8;
        s->maxdata      = 0x0fff;
        s->range_table  = &pcmda12_ranges;
        s->insn_write   = pcmda12_ao_insn_write;
        s->insn_read    = pcmda12_ao_insn_read;

        ret = comedi_alloc_subdev_readback(s);
        if (ret)
                return ret;

        pcmda12_ao_reset(dev, s);

        return 0;
}

static struct comedi_driver pcmda12_driver = {
        .driver_name    = "pcmda12",
        .module         = THIS_MODULE,
        .attach         = pcmda12_attach,
        .detach         = comedi_legacy_detach,
};
module_comedi_driver(pcmda12_driver);

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