// SPDX-License-Identifier: GPL-2.0+
/*
 * comedi/drivers/cb_pcidda.c
 * Driver for the ComputerBoards / MeasurementComputing PCI-DDA series.
 *
 * Copyright (C) 2001 Ivan Martinez <ivanmr@altavista.com>
 * Copyright (C) 2001 Frank Mori Hess <fmhess@users.sourceforge.net>
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
 */

/*
 * Driver: cb_pcidda
 * Description: MeasurementComputing PCI-DDA series
 * Devices: [Measurement Computing] PCI-DDA08/12 (pci-dda08/12),
 *   PCI-DDA04/12 (pci-dda04/12), PCI-DDA02/12 (pci-dda02/12),
 *   PCI-DDA08/16 (pci-dda08/16), PCI-DDA04/16 (pci-dda04/16),
 *   PCI-DDA02/16 (pci-dda02/16)
 * Author: Ivan Martinez <ivanmr@altavista.com>
 *         Frank Mori Hess <fmhess@users.sourceforge.net>
 * Status: works
 *
 * Configuration options: not applicable, uses PCI auto config
 *
 * Only simple analog output writing is supported.
 */

#include <linux/module.h>
#include <linux/comedi/comedi_pci.h>
#include <linux/comedi/comedi_8255.h>

#define EEPROM_SIZE     128     /*  number of entries in eeprom */
/* maximum number of ao channels for supported boards */
#define MAX_AO_CHANNELS 8

/* Digital I/O registers */
#define CB_DDA_DIO0_8255_BASE           0x00
#define CB_DDA_DIO1_8255_BASE           0x04

/* DAC registers */
#define CB_DDA_DA_CTRL_REG              0x00       /* D/A Control Register  */
#define CB_DDA_DA_CTRL_SU               BIT(0)   /*  Simultaneous update  */
#define CB_DDA_DA_CTRL_EN               BIT(1)   /*  Enable specified DAC */
#define CB_DDA_DA_CTRL_DAC(x)           ((x) << 2) /*  Specify DAC channel  */
#define CB_DDA_DA_CTRL_RANGE2V5         (0 << 6)   /*  2.5V range           */
#define CB_DDA_DA_CTRL_RANGE5V          (2 << 6)   /*  5V range             */
#define CB_DDA_DA_CTRL_RANGE10V         (3 << 6)   /*  10V range            */
#define CB_DDA_DA_CTRL_UNIP             BIT(8)   /*  Unipolar range       */

#define DACALIBRATION1  4       /*  D/A CALIBRATION REGISTER 1 */
/* write bits */
/* serial data input for eeprom, caldacs, reference dac */
#define SERIAL_IN_BIT   0x1
#define CAL_CHANNEL_MASK        (0x7 << 1)
#define CAL_CHANNEL_BITS(channel)       (((channel) << 1) & CAL_CHANNEL_MASK)
/* read bits */
#define CAL_COUNTER_MASK        0x1f
/* calibration counter overflow status bit */
#define CAL_COUNTER_OVERFLOW_BIT        0x20
/* analog output is less than reference dac voltage */
#define AO_BELOW_REF_BIT        0x40
#define SERIAL_OUT_BIT  0x80    /*  serial data out, for reading from eeprom */

#define DACALIBRATION2  6       /*  D/A CALIBRATION REGISTER 2 */
#define SELECT_EEPROM_BIT       0x1     /*  send serial data in to eeprom */
/* don't send serial data to MAX542 reference dac */
#define DESELECT_REF_DAC_BIT    0x2
/* don't send serial data to caldac n */
#define DESELECT_CALDAC_BIT(n)  (0x4 << (n))
/* manual says to set this bit with no explanation */
#define DUMMY_BIT       0x40

#define CB_DDA_DA_DATA_REG(x)           (0x08 + ((x) * 2))

/* Offsets for the caldac channels */
#define CB_DDA_CALDAC_FINE_GAIN         0
#define CB_DDA_CALDAC_COURSE_GAIN       1
#define CB_DDA_CALDAC_COURSE_OFFSET     2
#define CB_DDA_CALDAC_FINE_OFFSET       3

static const struct comedi_lrange cb_pcidda_ranges = {
        6, {
                BIP_RANGE(10),
                BIP_RANGE(5),
                BIP_RANGE(2.5),
                UNI_RANGE(10),
                UNI_RANGE(5),
                UNI_RANGE(2.5)
        }
};

enum cb_pcidda_boardid {
        BOARD_DDA02_12,
        BOARD_DDA04_12,
        BOARD_DDA08_12,
        BOARD_DDA02_16,
        BOARD_DDA04_16,
        BOARD_DDA08_16,
};

struct cb_pcidda_board {
        const char *name;
        int ao_chans;
        int ao_bits;
};

static const struct cb_pcidda_board cb_pcidda_boards[] = {
        [BOARD_DDA02_12] = {
                .name           = "pci-dda02/12",
                .ao_chans       = 2,
                .ao_bits        = 12,
        },
        [BOARD_DDA04_12] = {
                .name           = "pci-dda04/12",
                .ao_chans       = 4,
                .ao_bits        = 12,
        },
        [BOARD_DDA08_12] = {
                .name           = "pci-dda08/12",
                .ao_chans       = 8,
                .ao_bits        = 12,
        },
        [BOARD_DDA02_16] = {
                .name           = "pci-dda02/16",
                .ao_chans       = 2,
                .ao_bits        = 16,
        },
        [BOARD_DDA04_16] = {
                .name           = "pci-dda04/16",
                .ao_chans       = 4,
                .ao_bits        = 16,
        },
        [BOARD_DDA08_16] = {
                .name           = "pci-dda08/16",
                .ao_chans       = 8,
                .ao_bits        = 16,
        },
};

struct cb_pcidda_private {
        unsigned long daqio;
        /* bits last written to da calibration register 1 */
        unsigned int dac_cal1_bits;
        /* current range settings for output channels */
        unsigned int ao_range[MAX_AO_CHANNELS];
        u16 eeprom_data[EEPROM_SIZE];   /*  software copy of board's eeprom */
};

/* lowlevel read from eeprom */
static unsigned int cb_pcidda_serial_in(struct comedi_device *dev)
{
        struct cb_pcidda_private *devpriv = dev->private;
        unsigned int value = 0;
        int i;
        const int value_width = 16;     /*  number of bits wide values are */

        for (i = 1; i <= value_width; i++) {
                /*  read bits most significant bit first */
                if (inw_p(devpriv->daqio + DACALIBRATION1) & SERIAL_OUT_BIT)
                        value |= 1 << (value_width - i);
        }

        return value;
}

/* lowlevel write to eeprom/dac */
static void cb_pcidda_serial_out(struct comedi_device *dev, unsigned int value,
                                 unsigned int num_bits)
{
        struct cb_pcidda_private *devpriv = dev->private;
        int i;

        for (i = 1; i <= num_bits; i++) {
                /*  send bits most significant bit first */
                if (value & (1 << (num_bits - i)))
                        devpriv->dac_cal1_bits |= SERIAL_IN_BIT;
                else
                        devpriv->dac_cal1_bits &= ~SERIAL_IN_BIT;
                outw_p(devpriv->dac_cal1_bits, devpriv->daqio + DACALIBRATION1);
        }
}

/* reads a 16 bit value from board's eeprom */
static unsigned int cb_pcidda_read_eeprom(struct comedi_device *dev,
                                          unsigned int address)
{
        struct cb_pcidda_private *devpriv = dev->private;
        unsigned int i;
        unsigned int cal2_bits;
        unsigned int value;
        /* one caldac for every two dac channels */
        const int max_num_caldacs = 4;
        /* bits to send to tell eeprom we want to read */
        const int read_instruction = 0x6;
        const int instruction_length = 3;
        const int address_length = 8;

        /*  send serial output stream to eeprom */
        cal2_bits = SELECT_EEPROM_BIT | DESELECT_REF_DAC_BIT | DUMMY_BIT;
        /*  deactivate caldacs (one caldac for every two channels) */
        for (i = 0; i < max_num_caldacs; i++)
                cal2_bits |= DESELECT_CALDAC_BIT(i);
        outw_p(cal2_bits, devpriv->daqio + DACALIBRATION2);

        /*  tell eeprom we want to read */
        cb_pcidda_serial_out(dev, read_instruction, instruction_length);
        /*  send address we want to read from */
        cb_pcidda_serial_out(dev, address, address_length);

        value = cb_pcidda_serial_in(dev);

        /*  deactivate eeprom */
        cal2_bits &= ~SELECT_EEPROM_BIT;
        outw_p(cal2_bits, devpriv->daqio + DACALIBRATION2);

        return value;
}

/* writes to 8 bit calibration dacs */
static void cb_pcidda_write_caldac(struct comedi_device *dev,
                                   unsigned int caldac, unsigned int channel,
                                   unsigned int value)
{
        struct cb_pcidda_private *devpriv = dev->private;
        unsigned int cal2_bits;
        unsigned int i;
        /* caldacs use 3 bit channel specification */
        const int num_channel_bits = 3;
        const int num_caldac_bits = 8;  /*  8 bit calibration dacs */
        /* one caldac for every two dac channels */
        const int max_num_caldacs = 4;

        /* write 3 bit channel */
        cb_pcidda_serial_out(dev, channel, num_channel_bits);
        /*  write 8 bit caldac value */
        cb_pcidda_serial_out(dev, value, num_caldac_bits);

/*
 * latch stream into appropriate caldac deselect reference dac
 */
        cal2_bits = DESELECT_REF_DAC_BIT | DUMMY_BIT;
        /*  deactivate caldacs (one caldac for every two channels) */
        for (i = 0; i < max_num_caldacs; i++)
                cal2_bits |= DESELECT_CALDAC_BIT(i);
        /*  activate the caldac we want */
        cal2_bits &= ~DESELECT_CALDAC_BIT(caldac);
        outw_p(cal2_bits, devpriv->daqio + DACALIBRATION2);
        /*  deactivate caldac */
        cal2_bits |= DESELECT_CALDAC_BIT(caldac);
        outw_p(cal2_bits, devpriv->daqio + DACALIBRATION2);
}

/* set caldacs to eeprom values for given channel and range */
static void cb_pcidda_calibrate(struct comedi_device *dev, unsigned int channel,
                                unsigned int range)
{
        struct cb_pcidda_private *devpriv = dev->private;
        unsigned int caldac = channel / 2;      /* two caldacs per channel */
        unsigned int chan = 4 * (channel % 2);  /* caldac channel base */
        unsigned int index = 2 * range + 12 * channel;
        unsigned int offset;
        unsigned int gain;

        /* save range so we can tell when we need to readjust calibration */
        devpriv->ao_range[channel] = range;

        /* get values from eeprom data */
        offset = devpriv->eeprom_data[0x7 + index];
        gain = devpriv->eeprom_data[0x8 + index];

        /* set caldacs */
        cb_pcidda_write_caldac(dev, caldac, chan + CB_DDA_CALDAC_COURSE_OFFSET,
                               (offset >> 8) & 0xff);
        cb_pcidda_write_caldac(dev, caldac, chan + CB_DDA_CALDAC_FINE_OFFSET,
                               offset & 0xff);
        cb_pcidda_write_caldac(dev, caldac, chan + CB_DDA_CALDAC_COURSE_GAIN,
                               (gain >> 8) & 0xff);
        cb_pcidda_write_caldac(dev, caldac, chan + CB_DDA_CALDAC_FINE_GAIN,
                               gain & 0xff);
}

static int cb_pcidda_ao_insn_write(struct comedi_device *dev,
                                   struct comedi_subdevice *s,
                                   struct comedi_insn *insn,
                                   unsigned int *data)
{
        struct cb_pcidda_private *devpriv = dev->private;
        unsigned int channel = CR_CHAN(insn->chanspec);
        unsigned int range = CR_RANGE(insn->chanspec);
        unsigned int ctrl;
        unsigned int i;

        if (range != devpriv->ao_range[channel])
                cb_pcidda_calibrate(dev, channel, range);

        ctrl = CB_DDA_DA_CTRL_EN | CB_DDA_DA_CTRL_DAC(channel);

        switch (range) {
        case 0:
        case 3:
                ctrl |= CB_DDA_DA_CTRL_RANGE10V;
                break;
        case 1:
        case 4:
                ctrl |= CB_DDA_DA_CTRL_RANGE5V;
                break;
        case 2:
        case 5:
                ctrl |= CB_DDA_DA_CTRL_RANGE2V5;
                break;
        }

        if (range > 2)
                ctrl |= CB_DDA_DA_CTRL_UNIP;

        outw(ctrl, devpriv->daqio + CB_DDA_DA_CTRL_REG);

        for (i = 0; i < insn->n; i++)
                outw(data[i], devpriv->daqio + CB_DDA_DA_DATA_REG(channel));

        return insn->n;
}

static int cb_pcidda_auto_attach(struct comedi_device *dev,
                                 unsigned long context)
{
        struct pci_dev *pcidev = comedi_to_pci_dev(dev);
        const struct cb_pcidda_board *board = NULL;
        struct cb_pcidda_private *devpriv;
        struct comedi_subdevice *s;
        int i;
        int ret;

        if (context < ARRAY_SIZE(cb_pcidda_boards))
                board = &cb_pcidda_boards[context];
        if (!board)
                return -ENODEV;
        dev->board_ptr = board;
        dev->board_name = board->name;

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

        ret = comedi_pci_enable(dev);
        if (ret)
                return ret;
        dev->iobase = pci_resource_start(pcidev, 2);
        devpriv->daqio = pci_resource_start(pcidev, 3);

        ret = comedi_alloc_subdevices(dev, 3);
        if (ret)
                return ret;

        s = &dev->subdevices[0];
        /* analog output subdevice */
        s->type = COMEDI_SUBD_AO;
        s->subdev_flags = SDF_WRITABLE;
        s->n_chan = board->ao_chans;
        s->maxdata = (1 << board->ao_bits) - 1;
        s->range_table = &cb_pcidda_ranges;
        s->insn_write = cb_pcidda_ao_insn_write;

        /* two 8255 digital io subdevices */
        for (i = 0; i < 2; i++) {
                s = &dev->subdevices[1 + i];
                ret = subdev_8255_io_init(dev, s, i * I8255_SIZE);
                if (ret)
                        return ret;
        }

        /* Read the caldac eeprom data */
        for (i = 0; i < EEPROM_SIZE; i++)
                devpriv->eeprom_data[i] = cb_pcidda_read_eeprom(dev, i);

        /*  set calibrations dacs */
        for (i = 0; i < board->ao_chans; i++)
                cb_pcidda_calibrate(dev, i, devpriv->ao_range[i]);

        return 0;
}

static struct comedi_driver cb_pcidda_driver = {
        .driver_name    = "cb_pcidda",
        .module         = THIS_MODULE,
        .auto_attach    = cb_pcidda_auto_attach,
        .detach         = comedi_pci_detach,
};

static int cb_pcidda_pci_probe(struct pci_dev *dev,
                               const struct pci_device_id *id)
{
        return comedi_pci_auto_config(dev, &cb_pcidda_driver,
                                      id->driver_data);
}

static const struct pci_device_id cb_pcidda_pci_table[] = {
        { PCI_VDEVICE(CB, 0x0020), BOARD_DDA02_12 },
        { PCI_VDEVICE(CB, 0x0021), BOARD_DDA04_12 },
        { PCI_VDEVICE(CB, 0x0022), BOARD_DDA08_12 },
        { PCI_VDEVICE(CB, 0x0023), BOARD_DDA02_16 },
        { PCI_VDEVICE(CB, 0x0024), BOARD_DDA04_16 },
        { PCI_VDEVICE(CB, 0x0025), BOARD_DDA08_16 },
        { 0 }
};
MODULE_DEVICE_TABLE(pci, cb_pcidda_pci_table);

static struct pci_driver cb_pcidda_pci_driver = {
        .name           = "cb_pcidda",
        .id_table       = cb_pcidda_pci_table,
        .probe          = cb_pcidda_pci_probe,
        .remove         = comedi_pci_auto_unconfig,
};
module_comedi_pci_driver(cb_pcidda_driver, cb_pcidda_pci_driver);

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