// SPDX-License-Identifier: GPL-2.0+
/*
 * comedi/drivers/dt2815.c
 * Hardware driver for Data Translation DT2815
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1999 Anders Blomdell <anders.blomdell@control.lth.se>
 */
/*
 * Driver: dt2815
 * Description: Data Translation DT2815
 * Author: ds
 * Status: mostly complete, untested
 * Devices: [Data Translation] DT2815 (dt2815)
 *
 * I'm not sure anyone has ever tested this board.  If you have information
 * contrary, please update.
 *
 * Configuration options:
 * [0] - I/O port base base address
 * [1] - IRQ (unused)
 * [2] - Voltage unipolar/bipolar configuration
 *      0 == unipolar 5V  (0V -- +5V)
 *      1 == bipolar 5V  (-5V -- +5V)
 * [3] - Current offset configuration
 *      0 == disabled  (0mA -- +32mAV)
 *      1 == enabled  (+4mA -- +20mAV)
 * [4] - Firmware program configuration
 *      0 == program 1 (see manual table 5-4)
 *      1 == program 2 (see manual table 5-4)
 *      2 == program 3 (see manual table 5-4)
 *      3 == program 4 (see manual table 5-4)
 * [5] - Analog output 0 range configuration
 *      0 == voltage
 *      1 == current
 * [6] - Analog output 1 range configuration (same options)
 * [7] - Analog output 2 range configuration (same options)
 * [8] - Analog output 3 range configuration (same options)
 * [9] - Analog output 4 range configuration (same options)
 * [10] - Analog output 5 range configuration (same options)
 * [11] - Analog output 6 range configuration (same options)
 * [12] - Analog output 7 range configuration (same options)
 */

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

#define DT2815_DATA 0
#define DT2815_STATUS 1

struct dt2815_private {
        const struct comedi_lrange *range_type_list[8];
        unsigned int ao_readback[8];
};

static int dt2815_ao_status(struct comedi_device *dev,
                            struct comedi_subdevice *s,
                            struct comedi_insn *insn,
                            unsigned long context)
{
        unsigned int status;

        status = inb(dev->iobase + DT2815_STATUS);
        if (status == context)
                return 0;
        return -EBUSY;
}

static int dt2815_ao_insn_read(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn, unsigned int *data)
{
        struct dt2815_private *devpriv = dev->private;
        int i;
        int chan = CR_CHAN(insn->chanspec);

        for (i = 0; i < insn->n; i++)
                data[i] = devpriv->ao_readback[chan];

        return i;
}

static int dt2815_ao_insn(struct comedi_device *dev, struct comedi_subdevice *s,
                          struct comedi_insn *insn, unsigned int *data)
{
        struct dt2815_private *devpriv = dev->private;
        int i;
        int chan = CR_CHAN(insn->chanspec);
        unsigned int lo, hi;
        int ret;

        for (i = 0; i < insn->n; i++) {
                /* FIXME: lo bit 0 chooses voltage output or current output */
                lo = ((data[i] & 0x0f) << 4) | (chan << 1) | 0x01;
                hi = (data[i] & 0xff0) >> 4;

                ret = comedi_timeout(dev, s, insn, dt2815_ao_status, 0x00);
                if (ret)
                        return ret;

                outb(lo, dev->iobase + DT2815_DATA);

                ret = comedi_timeout(dev, s, insn, dt2815_ao_status, 0x10);
                if (ret)
                        return ret;

                outb(hi, dev->iobase + DT2815_DATA);

                devpriv->ao_readback[chan] = data[i];
        }
        return i;
}

/*
 * options[0]   Board base address
 * options[1]   IRQ (not applicable)
 * options[2]   Voltage unipolar/bipolar configuration
 *              0 == unipolar 5V  (0V -- +5V)
 *              1 == bipolar 5V  (-5V -- +5V)
 * options[3]   Current offset configuration
 *              0 == disabled  (0mA -- +32mAV)
 *              1 == enabled  (+4mA -- +20mAV)
 * options[4]   Firmware program configuration
 *              0 == program 1 (see manual table 5-4)
 *              1 == program 2 (see manual table 5-4)
 *              2 == program 3 (see manual table 5-4)
 *              3 == program 4 (see manual table 5-4)
 * options[5]   Analog output 0 range configuration
 *              0 == voltage
 *              1 == current
 * options[6]   Analog output 1 range configuration
 * ...
 * options[12]   Analog output 7 range configuration
 *              0 == voltage
 *              1 == current
 */

static int dt2815_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
        struct dt2815_private *devpriv;
        struct comedi_subdevice *s;
        int i;
        const struct comedi_lrange *current_range_type, *voltage_range_type;
        int ret;

        ret = comedi_request_region(dev, it->options[0], 0x2);
        if (ret)
                return ret;

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

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

        s = &dev->subdevices[0];
        /* ao subdevice */
        s->type = COMEDI_SUBD_AO;
        s->subdev_flags = SDF_WRITABLE;
        s->maxdata = 0xfff;
        s->n_chan = 8;
        s->insn_write = dt2815_ao_insn;
        s->insn_read = dt2815_ao_insn_read;
        s->range_table_list = devpriv->range_type_list;

        current_range_type = (it->options[3])
            ? &range_4_20mA : &range_0_32mA;
        voltage_range_type = (it->options[2])
            ? &range_bipolar5 : &range_unipolar5;
        for (i = 0; i < 8; i++) {
                devpriv->range_type_list[i] = (it->options[5 + i])
                    ? current_range_type : voltage_range_type;
        }

        /*
         * Check if hardware is present before attempting any I/O operations.
         * Reading 0xff from status register typically indicates no hardware
         * on the bus (floating bus reads as all 1s).
         */
        if (inb(dev->iobase + DT2815_STATUS) == 0xff) {
                dev_err(dev->class_dev,
                        "No hardware detected at I/O base 0x%lx\n",
                        dev->iobase);
                return -ENODEV;
        }

        /* Init the 2815 */
        outb(0x00, dev->iobase + DT2815_STATUS);
        for (i = 0; i < 100; i++) {
                /* This is incredibly slow (approx 20 ms) */
                unsigned int status;

                usleep_range(1000, 3000);
                status = inb(dev->iobase + DT2815_STATUS);
                if (status == 4) {
                        unsigned int program;

                        program = (it->options[4] & 0x3) << 3 | 0x7;
                        outb(program, dev->iobase + DT2815_DATA);
                        dev_dbg(dev->class_dev, "program: 0x%x (@t=%d)\n",
                                program, i);
                        break;
                } else if (status != 0x00) {
                        dev_dbg(dev->class_dev,
                                "unexpected status 0x%x (@t=%d)\n",
                                status, i);
                        if (status & 0x60)
                                outb(0x00, dev->iobase + DT2815_STATUS);
                }
        }

        return 0;
}

static struct comedi_driver dt2815_driver = {
        .driver_name    = "dt2815",
        .module         = THIS_MODULE,
        .attach         = dt2815_attach,
        .detach         = comedi_legacy_detach,
};
module_comedi_driver(dt2815_driver);

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