// SPDX-License-Identifier: GPL-2.0+
/*
 * addi_apci_2032.c
 * Copyright (C) 2004,2005  ADDI-DATA GmbH for the source code of this module.
 * Project manager: Eric Stolz
 *
 *      ADDI-DATA GmbH
 *      Dieselstrasse 3
 *      D-77833 Ottersweier
 *      Tel: +19(0)7223/9493-0
 *      Fax: +49(0)7223/9493-92
 *      http://www.addi-data.com
 *      info@addi-data.com
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/comedi/comedi_pci.h>

#include "addi_watchdog.h"

/*
 * PCI bar 1 I/O Register map
 */
#define APCI2032_DO_REG                 0x00
#define APCI2032_INT_CTRL_REG           0x04
#define APCI2032_INT_CTRL_VCC_ENA       BIT(0)
#define APCI2032_INT_CTRL_CC_ENA        BIT(1)
#define APCI2032_INT_STATUS_REG         0x08
#define APCI2032_INT_STATUS_VCC         BIT(0)
#define APCI2032_INT_STATUS_CC          BIT(1)
#define APCI2032_STATUS_REG             0x0c
#define APCI2032_STATUS_IRQ             BIT(0)
#define APCI2032_WDOG_REG               0x10

struct apci2032_int_private {
        spinlock_t spinlock;            /* protects the following members */
        bool active;                    /* an async command is running */
        unsigned char enabled_isns;     /* mask of enabled interrupt channels */
};

static int apci2032_do_insn_bits(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 struct comedi_insn *insn,
                                 unsigned int *data)
{
        s->state = inl(dev->iobase + APCI2032_DO_REG);

        if (comedi_dio_update_state(s, data))
                outl(s->state, dev->iobase + APCI2032_DO_REG);

        data[1] = s->state;

        return insn->n;
}

static int apci2032_int_insn_bits(struct comedi_device *dev,
                                  struct comedi_subdevice *s,
                                  struct comedi_insn *insn,
                                  unsigned int *data)
{
        data[1] = inl(dev->iobase + APCI2032_INT_STATUS_REG) & 3;
        return insn->n;
}

static void apci2032_int_stop(struct comedi_device *dev,
                              struct comedi_subdevice *s)
{
        struct apci2032_int_private *subpriv = s->private;

        subpriv->active = false;
        subpriv->enabled_isns = 0;
        outl(0x0, dev->iobase + APCI2032_INT_CTRL_REG);
}

static int apci2032_int_cmdtest(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_cmd *cmd)
{
        int err = 0;

        /* Step 1 : check if triggers are trivially valid */

        err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
        err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
        err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW);
        err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
        err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);

        if (err)
                return 1;

        /* Step 2a : make sure trigger sources are unique */
        err |= comedi_check_trigger_is_unique(cmd->stop_src);

        /* Step 2b : and mutually compatible */

        if (err)
                return 2;

        /* Step 3: check if arguments are trivially valid */

        err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
        err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
        err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
        err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
                                           cmd->chanlist_len);
        if (cmd->stop_src == TRIG_COUNT)
                err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
        else    /* TRIG_NONE */
                err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);

        if (err)
                return 3;

        /* Step 4: fix up any arguments */

        /* Step 5: check channel list if it exists */

        return 0;
}

static int apci2032_int_cmd(struct comedi_device *dev,
                            struct comedi_subdevice *s)
{
        struct comedi_cmd *cmd = &s->async->cmd;
        struct apci2032_int_private *subpriv = s->private;
        unsigned char enabled_isns;
        unsigned int n;
        unsigned long flags;

        enabled_isns = 0;
        for (n = 0; n < cmd->chanlist_len; n++)
                enabled_isns |= 1 << CR_CHAN(cmd->chanlist[n]);

        spin_lock_irqsave(&subpriv->spinlock, flags);

        subpriv->enabled_isns = enabled_isns;
        subpriv->active = true;
        outl(enabled_isns, dev->iobase + APCI2032_INT_CTRL_REG);

        spin_unlock_irqrestore(&subpriv->spinlock, flags);

        return 0;
}

static int apci2032_int_cancel(struct comedi_device *dev,
                               struct comedi_subdevice *s)
{
        struct apci2032_int_private *subpriv = s->private;
        unsigned long flags;

        spin_lock_irqsave(&subpriv->spinlock, flags);
        if (subpriv->active)
                apci2032_int_stop(dev, s);
        spin_unlock_irqrestore(&subpriv->spinlock, flags);

        return 0;
}

static irqreturn_t apci2032_interrupt(int irq, void *d)
{
        struct comedi_device *dev = d;
        struct comedi_subdevice *s = dev->read_subdev;
        struct comedi_cmd *cmd = &s->async->cmd;
        struct apci2032_int_private *subpriv;
        unsigned int val;

        if (!dev->attached)
                return IRQ_NONE;

        /* Check if VCC OR CC interrupt has occurred */
        val = inl(dev->iobase + APCI2032_STATUS_REG) & APCI2032_STATUS_IRQ;
        if (!val)
                return IRQ_NONE;

        subpriv = s->private;
        spin_lock(&subpriv->spinlock);

        val = inl(dev->iobase + APCI2032_INT_STATUS_REG) & 3;
        /* Disable triggered interrupt sources. */
        outl(~val & 3, dev->iobase + APCI2032_INT_CTRL_REG);
        /*
         * Note: We don't reenable the triggered interrupt sources because they
         * are level-sensitive, hardware error status interrupt sources and
         * they'd keep triggering interrupts repeatedly.
         */

        if (subpriv->active && (val & subpriv->enabled_isns) != 0) {
                unsigned short bits = 0;
                int i;

                /* Bits in scan data correspond to indices in channel list. */
                for (i = 0; i < cmd->chanlist_len; i++) {
                        unsigned int chan = CR_CHAN(cmd->chanlist[i]);

                        if (val & (1 << chan))
                                bits |= (1 << i);
                }

                comedi_buf_write_samples(s, &bits, 1);

                if (cmd->stop_src == TRIG_COUNT &&
                    s->async->scans_done >= cmd->stop_arg)
                        s->async->events |= COMEDI_CB_EOA;
        }

        spin_unlock(&subpriv->spinlock);

        comedi_handle_events(dev, s);

        return IRQ_HANDLED;
}

static int apci2032_reset(struct comedi_device *dev)
{
        outl(0x0, dev->iobase + APCI2032_DO_REG);
        outl(0x0, dev->iobase + APCI2032_INT_CTRL_REG);

        addi_watchdog_reset(dev->iobase + APCI2032_WDOG_REG);

        return 0;
}

static int apci2032_auto_attach(struct comedi_device *dev,
                                unsigned long context_unused)
{
        struct pci_dev *pcidev = comedi_to_pci_dev(dev);
        struct comedi_subdevice *s;
        int ret;

        ret = comedi_pci_enable(dev);
        if (ret)
                return ret;
        dev->iobase = pci_resource_start(pcidev, 1);
        apci2032_reset(dev);

        if (pcidev->irq > 0) {
                ret = request_irq(pcidev->irq, apci2032_interrupt,
                                  IRQF_SHARED, dev->board_name, dev);
                if (ret == 0)
                        dev->irq = pcidev->irq;
        }

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

        /* Initialize the digital output subdevice */
        s = &dev->subdevices[0];
        s->type         = COMEDI_SUBD_DO;
        s->subdev_flags = SDF_WRITABLE;
        s->n_chan       = 32;
        s->maxdata      = 1;
        s->range_table  = &range_digital;
        s->insn_bits    = apci2032_do_insn_bits;

        /* Initialize the watchdog subdevice */
        s = &dev->subdevices[1];
        ret = addi_watchdog_init(s, dev->iobase + APCI2032_WDOG_REG);
        if (ret)
                return ret;

        /* Initialize the interrupt subdevice */
        s = &dev->subdevices[2];
        s->type         = COMEDI_SUBD_DI;
        s->subdev_flags = SDF_READABLE;
        s->n_chan       = 2;
        s->maxdata      = 1;
        s->range_table  = &range_digital;
        s->insn_bits    = apci2032_int_insn_bits;
        if (dev->irq) {
                struct apci2032_int_private *subpriv;

                dev->read_subdev = s;
                subpriv = kzalloc_obj(*subpriv);
                if (!subpriv)
                        return -ENOMEM;
                spin_lock_init(&subpriv->spinlock);
                s->private      = subpriv;
                s->subdev_flags = SDF_READABLE | SDF_CMD_READ | SDF_PACKED;
                s->len_chanlist = 2;
                s->do_cmdtest   = apci2032_int_cmdtest;
                s->do_cmd       = apci2032_int_cmd;
                s->cancel       = apci2032_int_cancel;
        }

        return 0;
}

static void apci2032_detach(struct comedi_device *dev)
{
        if (dev->iobase)
                apci2032_reset(dev);
        comedi_pci_detach(dev);
        if (dev->read_subdev)
                kfree(dev->read_subdev->private);
}

static struct comedi_driver apci2032_driver = {
        .driver_name    = "addi_apci_2032",
        .module         = THIS_MODULE,
        .auto_attach    = apci2032_auto_attach,
        .detach         = apci2032_detach,
};

static int apci2032_pci_probe(struct pci_dev *dev,
                              const struct pci_device_id *id)
{
        return comedi_pci_auto_config(dev, &apci2032_driver, id->driver_data);
}

static const struct pci_device_id apci2032_pci_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_ADDIDATA, 0x1004) },
        { 0 }
};
MODULE_DEVICE_TABLE(pci, apci2032_pci_table);

static struct pci_driver apci2032_pci_driver = {
        .name           = "addi_apci_2032",
        .id_table       = apci2032_pci_table,
        .probe          = apci2032_pci_probe,
        .remove         = comedi_pci_auto_unconfig,
};
module_comedi_pci_driver(apci2032_driver, apci2032_pci_driver);

MODULE_AUTHOR("Comedi https://www.comedi.org");
MODULE_DESCRIPTION("ADDI-DATA APCI-2032, 32 channel DO boards");
MODULE_LICENSE("GPL");