// SPDX-License-Identifier: GPL-2.0+
/*
 * Comedi driver for National Instruments PCI-DIO-32HS
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1999,2002 David A. Schleef <ds@schleef.org>
 */

/*
 * Driver: ni_pcidio
 * Description: National Instruments PCI-DIO32HS, PCI-6533
 * Author: ds
 * Status: works
 * Devices: [National Instruments] PCI-DIO-32HS (ni_pcidio)
 *   [National Instruments] PXI-6533, PCI-6533 (pxi-6533)
 *   [National Instruments] PCI-6534 (pci-6534)
 * Updated: Mon, 09 Jan 2012 14:27:23 +0000
 *
 * The DIO32HS board appears as one subdevice, with 32 channels. Each
 * channel is individually I/O configurable. The channel order is 0=A0,
 * 1=A1, 2=A2, ... 8=B0, 16=C0, 24=D0. The driver only supports simple
 * digital I/O; no handshaking is supported.
 *
 * DMA mostly works for the PCI-DIO32HS, but only in timed input mode.
 *
 * The PCI-DIO-32HS/PCI-6533 has a configurable external trigger. Setting
 * scan_begin_arg to 0 or CR_EDGE triggers on the leading edge. Setting
 * scan_begin_arg to CR_INVERT or (CR_EDGE | CR_INVERT) triggers on the
 * trailing edge.
 *
 * This driver could be easily modified to support AT-MIO32HS and AT-MIO96.
 *
 * The PCI-6534 requires a firmware upload after power-up to work, the
 * firmware data and instructions for loading it with comedi_config
 * it are contained in the comedi_nonfree_firmware tarball available from
 * https://www.comedi.org
 */

#define USE_DMA

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/sched.h>

#include "../comedi_pci.h"

#include "mite.h"

/* defines for the PCI-DIO-32HS */

#define WINDOW_ADDRESS                  4       /* W */
#define INTERRUPT_AND_WINDOW_STATUS     4       /* R */
#define INT_STATUS_1                            BIT(0)
#define INT_STATUS_2                            BIT(1)
#define WINDOW_ADDRESS_STATUS_MASK              0x7c

#define MASTER_DMA_AND_INTERRUPT_CONTROL 5      /* W */
#define INTERRUPT_LINE(x)                       ((x) & 3)
#define OPEN_INT                                BIT(2)
#define GROUP_STATUS                    5       /* R */
#define DATA_LEFT                               BIT(0)
#define REQ                                     BIT(2)
#define STOP_TRIG                               BIT(3)

#define GROUP_1_FLAGS                   6       /* R */
#define GROUP_2_FLAGS                   7       /* R */
#define TRANSFER_READY                          BIT(0)
#define COUNT_EXPIRED                           BIT(1)
#define WAITED                                  BIT(5)
#define PRIMARY_TC                              BIT(6)
#define SECONDARY_TC                            BIT(7)
  /* #define SerialRose */
  /* #define ReqRose */
  /* #define Paused */

#define GROUP_1_FIRST_CLEAR             6       /* W */
#define GROUP_2_FIRST_CLEAR             7       /* W */
#define CLEAR_WAITED                            BIT(3)
#define CLEAR_PRIMARY_TC                        BIT(4)
#define CLEAR_SECONDARY_TC                      BIT(5)
#define DMA_RESET                               BIT(6)
#define FIFO_RESET                              BIT(7)
#define CLEAR_ALL                               0xf8

#define GROUP_1_FIFO                    8       /* W */
#define GROUP_2_FIFO                    12      /* W */

#define TRANSFER_COUNT                  20
#define CHIP_ID_D                       24
#define CHIP_ID_I                       25
#define CHIP_ID_O                       26
#define CHIP_VERSION                    27
#define PORT_IO(x)                      (28 + (x))
#define PORT_PIN_DIRECTIONS(x)          (32 + (x))
#define PORT_PIN_MASK(x)                (36 + (x))
#define PORT_PIN_POLARITIES(x)          (40 + (x))

#define MASTER_CLOCK_ROUTING            45
#define RTSI_CLOCKING(x)                        (((x) & 3) << 4)

#define GROUP_1_SECOND_CLEAR            46      /* W */
#define GROUP_2_SECOND_CLEAR            47      /* W */
#define CLEAR_EXPIRED                           BIT(0)

#define PORT_PATTERN(x)                 (48 + (x))

#define DATA_PATH                       64
#define FIFO_ENABLE_A           BIT(0)
#define FIFO_ENABLE_B           BIT(1)
#define FIFO_ENABLE_C           BIT(2)
#define FIFO_ENABLE_D           BIT(3)
#define FUNNELING(x)            (((x) & 3) << 4)
#define GROUP_DIRECTION         BIT(7)

#define PROTOCOL_REGISTER_1             65
#define OP_MODE                 PROTOCOL_REGISTER_1
#define RUN_MODE(x)             ((x) & 7)
#define NUMBERED                BIT(3)

#define PROTOCOL_REGISTER_2             66
#define CLOCK_REG                       PROTOCOL_REGISTER_2
#define CLOCK_LINE(x)           (((x) & 3) << 5)
#define INVERT_STOP_TRIG                BIT(7)
#define DATA_LATCHING(x)       (((x) & 3) << 5)

#define PROTOCOL_REGISTER_3             67
#define SEQUENCE                        PROTOCOL_REGISTER_3

#define PROTOCOL_REGISTER_14            68      /* 16 bit */
#define CLOCK_SPEED                     PROTOCOL_REGISTER_14

#define PROTOCOL_REGISTER_4             70
#define REQ_REG                 PROTOCOL_REGISTER_4
#define REQ_CONDITIONING(x)     (((x) & 7) << 3)

#define PROTOCOL_REGISTER_5             71
#define BLOCK_MODE                      PROTOCOL_REGISTER_5

#define FIFO_Control                    72
#define READY_LEVEL(x)          ((x) & 7)

#define PROTOCOL_REGISTER_6             73
#define LINE_POLARITIES         PROTOCOL_REGISTER_6
#define INVERT_ACK              BIT(0)
#define INVERT_REQ              BIT(1)
#define INVERT_CLOCK            BIT(2)
#define INVERT_SERIAL           BIT(3)
#define OPEN_ACK                BIT(4)
#define OPEN_CLOCK              BIT(5)

#define PROTOCOL_REGISTER_7             74
#define ACK_SER                 PROTOCOL_REGISTER_7
#define ACK_LINE(x)             (((x) & 3) << 2)
#define EXCHANGE_PINS           BIT(7)

#define INTERRUPT_CONTROL               75
/* bits same as flags */

#define DMA_LINE_CONTROL_GROUP1         76
#define DMA_LINE_CONTROL_GROUP2         108

/* channel zero is none */
static inline unsigned int primary_DMAChannel_bits(unsigned int channel)
{
        return channel & 0x3;
}

static inline unsigned int secondary_DMAChannel_bits(unsigned int channel)
{
        return (channel << 2) & 0xc;
}

#define TRANSFER_SIZE_CONTROL           77
#define TRANSFER_WIDTH(x)       ((x) & 3)
#define TRANSFER_LENGTH(x)      (((x) & 3) << 3)
#define REQUIRE_R_LEVEL        BIT(5)

#define PROTOCOL_REGISTER_15            79
#define DAQ_OPTIONS                     PROTOCOL_REGISTER_15
#define START_SOURCE(x)                 ((x) & 0x3)
#define INVERT_START                            BIT(2)
#define STOP_SOURCE(x)                          (((x) & 0x3) << 3)
#define REQ_START                               BIT(6)
#define PRE_START                               BIT(7)

#define PATTERN_DETECTION               81
#define DETECTION_METHOD                        BIT(0)
#define INVERT_MATCH                            BIT(1)
#define IE_PATTERN_DETECTION                    BIT(2)

#define PROTOCOL_REGISTER_9             82
#define REQ_DELAY                       PROTOCOL_REGISTER_9

#define PROTOCOL_REGISTER_10            83
#define REQ_NOT_DELAY                   PROTOCOL_REGISTER_10

#define PROTOCOL_REGISTER_11            84
#define ACK_DELAY                       PROTOCOL_REGISTER_11

#define PROTOCOL_REGISTER_12            85
#define ACK_NOT_DELAY                   PROTOCOL_REGISTER_12

#define PROTOCOL_REGISTER_13            86
#define DATA_1_DELAY                    PROTOCOL_REGISTER_13

#define PROTOCOL_REGISTER_8             88      /* 32 bit */
#define START_DELAY                     PROTOCOL_REGISTER_8

/* Firmware files for PCI-6524 */
#define FW_PCI_6534_MAIN                "ni6534a.bin"
#define FW_PCI_6534_SCARAB_DI           "niscrb01.bin"
#define FW_PCI_6534_SCARAB_DO           "niscrb02.bin"
MODULE_FIRMWARE(FW_PCI_6534_MAIN);
MODULE_FIRMWARE(FW_PCI_6534_SCARAB_DI);
MODULE_FIRMWARE(FW_PCI_6534_SCARAB_DO);

enum pci_6534_firmware_registers {      /* 16 bit */
        Firmware_Control_Register = 0x100,
        Firmware_Status_Register = 0x104,
        Firmware_Data_Register = 0x108,
        Firmware_Mask_Register = 0x10c,
        Firmware_Debug_Register = 0x110,
};

/* main fpga registers (32 bit)*/
enum pci_6534_fpga_registers {
        FPGA_Control1_Register = 0x200,
        FPGA_Control2_Register = 0x204,
        FPGA_Irq_Mask_Register = 0x208,
        FPGA_Status_Register = 0x20c,
        FPGA_Signature_Register = 0x210,
        FPGA_SCALS_Counter_Register = 0x280,    /*write-clear */
        FPGA_SCAMS_Counter_Register = 0x284,    /*write-clear */
        FPGA_SCBLS_Counter_Register = 0x288,    /*write-clear */
        FPGA_SCBMS_Counter_Register = 0x28c,    /*write-clear */
        FPGA_Temp_Control_Register = 0x2a0,
        FPGA_DAR_Register = 0x2a8,
        FPGA_ELC_Read_Register = 0x2b8,
        FPGA_ELC_Write_Register = 0x2bc,
};

enum FPGA_Control_Bits {
        FPGA_Enable_Bit = 0x8000,
};

#define TIMER_BASE 50           /* nanoseconds */

#ifdef USE_DMA
#define INT_EN (COUNT_EXPIRED | WAITED | PRIMARY_TC | SECONDARY_TC)
#else
#define INT_EN (TRANSFER_READY | COUNT_EXPIRED | WAITED \
                | PRIMARY_TC | SECONDARY_TC)
#endif

enum nidio_boardid {
        BOARD_PCIDIO_32HS,
        BOARD_PXI6533,
        BOARD_PCI6534,
};

struct nidio_board {
        const char *name;
        unsigned int uses_firmware:1;
        unsigned int dio_speed;
};

static const struct nidio_board nidio_boards[] = {
        [BOARD_PCIDIO_32HS] = {
                .name           = "pci-dio-32hs",
                .dio_speed      = 50,
        },
        [BOARD_PXI6533] = {
                .name           = "pxi-6533",
                .dio_speed      = 50,
        },
        [BOARD_PCI6534] = {
                .name           = "pci-6534",
                .uses_firmware  = 1,
                .dio_speed      = 50,
        },
};

struct nidio96_private {
        struct mite *mite;
        int boardtype;
        int dio;
        unsigned short OP_MODEBits;
        struct mite_channel *di_mite_chan;
        struct mite_ring *di_mite_ring;
        spinlock_t mite_channel_lock;
};

static int ni_pcidio_request_di_mite_channel(struct comedi_device *dev)
{
        struct nidio96_private *devpriv = dev->private;
        unsigned long flags;

        spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
        BUG_ON(devpriv->di_mite_chan);
        devpriv->di_mite_chan =
            mite_request_channel_in_range(devpriv->mite,
                                          devpriv->di_mite_ring, 1, 2);
        if (!devpriv->di_mite_chan) {
                spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
                dev_err(dev->class_dev, "failed to reserve mite dma channel\n");
                return -EBUSY;
        }
        devpriv->di_mite_chan->dir = COMEDI_INPUT;
        writeb(primary_DMAChannel_bits(devpriv->di_mite_chan->channel) |
               secondary_DMAChannel_bits(devpriv->di_mite_chan->channel),
               dev->mmio + DMA_LINE_CONTROL_GROUP1);
        spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
        return 0;
}

static void ni_pcidio_release_di_mite_channel(struct comedi_device *dev)
{
        struct nidio96_private *devpriv = dev->private;
        unsigned long flags;

        spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
        if (devpriv->di_mite_chan) {
                mite_release_channel(devpriv->di_mite_chan);
                devpriv->di_mite_chan = NULL;
                writeb(primary_DMAChannel_bits(0) |
                       secondary_DMAChannel_bits(0),
                       dev->mmio + DMA_LINE_CONTROL_GROUP1);
        }
        spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
}

static int setup_mite_dma(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct nidio96_private *devpriv = dev->private;
        int retval;
        unsigned long flags;

        retval = ni_pcidio_request_di_mite_channel(dev);
        if (retval)
                return retval;

        /* write alloc the entire buffer */
        comedi_buf_write_alloc(s, s->async->prealloc_bufsz);

        spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
        if (devpriv->di_mite_chan) {
                mite_prep_dma(devpriv->di_mite_chan, 32, 32);
                mite_dma_arm(devpriv->di_mite_chan);
        } else {
                retval = -EIO;
        }
        spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);

        return retval;
}

static int ni_pcidio_poll(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct nidio96_private *devpriv = dev->private;
        unsigned long irq_flags;
        int count;

        spin_lock_irqsave(&dev->spinlock, irq_flags);
        spin_lock(&devpriv->mite_channel_lock);
        if (devpriv->di_mite_chan)
                mite_sync_dma(devpriv->di_mite_chan, s);
        spin_unlock(&devpriv->mite_channel_lock);
        count = comedi_buf_n_bytes_ready(s);
        spin_unlock_irqrestore(&dev->spinlock, irq_flags);
        return count;
}

static irqreturn_t nidio_interrupt(int irq, void *d)
{
        struct comedi_device *dev = d;
        struct nidio96_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
        struct comedi_async *async = s->async;
        unsigned int auxdata;
        int flags;
        int status;
        int work = 0;

        /* interrupcions parasites */
        if (!dev->attached) {
                /* assume it's from another card */
                return IRQ_NONE;
        }

        /* Lock to avoid race with comedi_poll */
        spin_lock(&dev->spinlock);

        status = readb(dev->mmio + INTERRUPT_AND_WINDOW_STATUS);
        flags = readb(dev->mmio + GROUP_1_FLAGS);

        spin_lock(&devpriv->mite_channel_lock);
        if (devpriv->di_mite_chan) {
                mite_ack_linkc(devpriv->di_mite_chan, s, false);
                /* XXX need to byteswap sync'ed dma */
        }
        spin_unlock(&devpriv->mite_channel_lock);

        while (status & DATA_LEFT) {
                work++;
                if (work > 20) {
                        dev_dbg(dev->class_dev, "too much work in interrupt\n");
                        writeb(0x00,
                               dev->mmio + MASTER_DMA_AND_INTERRUPT_CONTROL);
                        break;
                }

                flags &= INT_EN;

                if (flags & TRANSFER_READY) {
                        while (flags & TRANSFER_READY) {
                                work++;
                                if (work > 100) {
                                        dev_dbg(dev->class_dev,
                                                "too much work in interrupt\n");
                                        writeb(0x00, dev->mmio +
                                               MASTER_DMA_AND_INTERRUPT_CONTROL
                                              );
                                        goto out;
                                }
                                auxdata = readl(dev->mmio + GROUP_1_FIFO);
                                comedi_buf_write_samples(s, &auxdata, 1);
                                flags = readb(dev->mmio + GROUP_1_FLAGS);
                        }
                }

                if (flags & COUNT_EXPIRED) {
                        writeb(CLEAR_EXPIRED, dev->mmio + GROUP_1_SECOND_CLEAR);
                        async->events |= COMEDI_CB_EOA;

                        writeb(0x00, dev->mmio + OP_MODE);
                        break;
                } else if (flags & WAITED) {
                        writeb(CLEAR_WAITED, dev->mmio + GROUP_1_FIRST_CLEAR);
                        async->events |= COMEDI_CB_ERROR;
                        break;
                } else if (flags & PRIMARY_TC) {
                        writeb(CLEAR_PRIMARY_TC,
                               dev->mmio + GROUP_1_FIRST_CLEAR);
                        async->events |= COMEDI_CB_EOA;
                } else if (flags & SECONDARY_TC) {
                        writeb(CLEAR_SECONDARY_TC,
                               dev->mmio + GROUP_1_FIRST_CLEAR);
                        async->events |= COMEDI_CB_EOA;
                }

                flags = readb(dev->mmio + GROUP_1_FLAGS);
                status = readb(dev->mmio + INTERRUPT_AND_WINDOW_STATUS);
        }

out:
        comedi_handle_events(dev, s);
#if 0
        if (!tag)
                writeb(0x03, dev->mmio + MASTER_DMA_AND_INTERRUPT_CONTROL);
#endif

        spin_unlock(&dev->spinlock);
        return IRQ_HANDLED;
}

static int ni_pcidio_insn_config(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 struct comedi_insn *insn,
                                 unsigned int *data)
{
        int ret;

        if (data[0] == INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS) {
                const struct nidio_board *board = dev->board_ptr;

                /* we don't care about actual channels */
                data[1] = board->dio_speed;
                data[2] = 0;
                return 0;
        }

        ret = comedi_dio_insn_config(dev, s, insn, data, 0);
        if (ret)
                return ret;

        writel(s->io_bits, dev->mmio + PORT_PIN_DIRECTIONS(0));

        return insn->n;
}

static int ni_pcidio_insn_bits(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn,
                               unsigned int *data)
{
        if (comedi_dio_update_state(s, data))
                writel(s->state, dev->mmio + PORT_IO(0));

        data[1] = readl(dev->mmio + PORT_IO(0));

        return insn->n;
}

static int ni_pcidio_ns_to_timer(int *nanosec, unsigned int flags)
{
        int divider, base;

        base = TIMER_BASE;

        switch (flags & CMDF_ROUND_MASK) {
        case CMDF_ROUND_NEAREST:
        default:
                divider = DIV_ROUND_CLOSEST(*nanosec, base);
                break;
        case CMDF_ROUND_DOWN:
                divider = (*nanosec) / base;
                break;
        case CMDF_ROUND_UP:
                divider = DIV_ROUND_UP(*nanosec, base);
                break;
        }

        *nanosec = base * divider;
        return divider;
}

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

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

        err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
        err |= comedi_check_trigger_src(&cmd->scan_begin_src,
                                        TRIG_TIMER | 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->start_src);
        err |= comedi_check_trigger_is_unique(cmd->scan_begin_src);
        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);

#define MAX_SPEED       (TIMER_BASE)    /* in nanoseconds */

        if (cmd->scan_begin_src == TRIG_TIMER) {
                err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
                                                    MAX_SPEED);
                /* no minimum speed */
        } else {
                /* TRIG_EXT */
                /* should be level/edge, hi/lo specification here */
                if ((cmd->scan_begin_arg & ~(CR_EDGE | CR_INVERT)) != 0) {
                        cmd->scan_begin_arg &= (CR_EDGE | CR_INVERT);
                        err |= -EINVAL;
                }
        }

        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 */

        if (cmd->scan_begin_src == TRIG_TIMER) {
                arg = cmd->scan_begin_arg;
                ni_pcidio_ns_to_timer(&arg, cmd->flags);
                err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
        }

        if (err)
                return 4;

        return 0;
}

static int ni_pcidio_inttrig(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             unsigned int trig_num)
{
        struct nidio96_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;

        if (trig_num != cmd->start_arg)
                return -EINVAL;

        writeb(devpriv->OP_MODEBits, dev->mmio + OP_MODE);
        s->async->inttrig = NULL;

        return 1;
}

static int ni_pcidio_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct nidio96_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;

        /* XXX configure ports for input */
        writel(0x0000, dev->mmio + PORT_PIN_DIRECTIONS(0));

        if (1) {
                /* enable fifos A B C D */
                writeb(0x0f, dev->mmio + DATA_PATH);

                /* set transfer width a 32 bits */
                writeb(TRANSFER_WIDTH(0) | TRANSFER_LENGTH(0),
                       dev->mmio + TRANSFER_SIZE_CONTROL);
        } else {
                writeb(0x03, dev->mmio + DATA_PATH);
                writeb(TRANSFER_WIDTH(3) | TRANSFER_LENGTH(0),
                       dev->mmio + TRANSFER_SIZE_CONTROL);
        }

        /* protocol configuration */
        if (cmd->scan_begin_src == TRIG_TIMER) {
                /* page 4-5, "input with internal REQs" */
                writeb(0, dev->mmio + OP_MODE);
                writeb(0x00, dev->mmio + CLOCK_REG);
                writeb(1, dev->mmio + SEQUENCE);
                writeb(0x04, dev->mmio + REQ_REG);
                writeb(4, dev->mmio + BLOCK_MODE);
                writeb(3, dev->mmio + LINE_POLARITIES);
                writeb(0xc0, dev->mmio + ACK_SER);
                writel(ni_pcidio_ns_to_timer(&cmd->scan_begin_arg,
                                             CMDF_ROUND_NEAREST),
                       dev->mmio + START_DELAY);
                writeb(1, dev->mmio + REQ_DELAY);
                writeb(1, dev->mmio + REQ_NOT_DELAY);
                writeb(1, dev->mmio + ACK_DELAY);
                writeb(0x0b, dev->mmio + ACK_NOT_DELAY);
                writeb(0x01, dev->mmio + DATA_1_DELAY);
                /*
                 * manual, page 4-5:
                 * CLOCK_SPEED comment is incorrectly listed on DAQ_OPTIONS
                 */
                writew(0, dev->mmio + CLOCK_SPEED);
                writeb(0, dev->mmio + DAQ_OPTIONS);
        } else {
                /* TRIG_EXT */
                /* page 4-5, "input with external REQs" */
                writeb(0, dev->mmio + OP_MODE);
                writeb(0x00, dev->mmio + CLOCK_REG);
                writeb(0, dev->mmio + SEQUENCE);
                writeb(0x00, dev->mmio + REQ_REG);
                writeb(4, dev->mmio + BLOCK_MODE);
                if (!(cmd->scan_begin_arg & CR_INVERT)) /* Leading Edge */
                        writeb(0, dev->mmio + LINE_POLARITIES);
                else                                    /* Trailing Edge */
                        writeb(2, dev->mmio + LINE_POLARITIES);
                writeb(0x00, dev->mmio + ACK_SER);
                writel(1, dev->mmio + START_DELAY);
                writeb(1, dev->mmio + REQ_DELAY);
                writeb(1, dev->mmio + REQ_NOT_DELAY);
                writeb(1, dev->mmio + ACK_DELAY);
                writeb(0x0C, dev->mmio + ACK_NOT_DELAY);
                writeb(0x10, dev->mmio + DATA_1_DELAY);
                writew(0, dev->mmio + CLOCK_SPEED);
                writeb(0x60, dev->mmio + DAQ_OPTIONS);
        }

        if (cmd->stop_src == TRIG_COUNT) {
                writel(cmd->stop_arg,
                       dev->mmio + TRANSFER_COUNT);
        } else {
                /* XXX */
        }

#ifdef USE_DMA
        writeb(CLEAR_PRIMARY_TC | CLEAR_SECONDARY_TC,
               dev->mmio + GROUP_1_FIRST_CLEAR);

        {
                int retval = setup_mite_dma(dev, s);

                if (retval)
                        return retval;
        }
#else
        writeb(0x00, dev->mmio + DMA_LINE_CONTROL_GROUP1);
#endif
        writeb(0x00, dev->mmio + DMA_LINE_CONTROL_GROUP2);

        /* clear and enable interrupts */
        writeb(0xff, dev->mmio + GROUP_1_FIRST_CLEAR);
        /* writeb(CLEAR_EXPIRED, dev->mmio+GROUP_1_SECOND_CLEAR); */

        writeb(INT_EN, dev->mmio + INTERRUPT_CONTROL);
        writeb(0x03, dev->mmio + MASTER_DMA_AND_INTERRUPT_CONTROL);

        if (cmd->stop_src == TRIG_NONE) {
                devpriv->OP_MODEBits = DATA_LATCHING(0) | RUN_MODE(7);
        } else {                /* TRIG_TIMER */
                devpriv->OP_MODEBits = NUMBERED | RUN_MODE(7);
        }
        if (cmd->start_src == TRIG_NOW) {
                /* start */
                writeb(devpriv->OP_MODEBits, dev->mmio + OP_MODE);
                s->async->inttrig = NULL;
        } else {
                /* TRIG_INT */
                s->async->inttrig = ni_pcidio_inttrig;
        }

        return 0;
}

static int ni_pcidio_cancel(struct comedi_device *dev,
                            struct comedi_subdevice *s)
{
        writeb(0x00, dev->mmio + MASTER_DMA_AND_INTERRUPT_CONTROL);
        ni_pcidio_release_di_mite_channel(dev);

        return 0;
}

static int ni_pcidio_change(struct comedi_device *dev,
                            struct comedi_subdevice *s)
{
        struct nidio96_private *devpriv = dev->private;
        int ret;

        ret = mite_buf_change(devpriv->di_mite_ring, s);
        if (ret < 0)
                return ret;

        memset(s->async->prealloc_buf, 0xaa, s->async->prealloc_bufsz);

        return 0;
}

static int pci_6534_load_fpga(struct comedi_device *dev,
                              const u8 *data, size_t data_len,
                              unsigned long context)
{
        static const int timeout = 1000;
        int fpga_index = context;
        int i;
        size_t j;

        writew(0x80 | fpga_index, dev->mmio + Firmware_Control_Register);
        writew(0xc0 | fpga_index, dev->mmio + Firmware_Control_Register);
        for (i = 0;
             (readw(dev->mmio + Firmware_Status_Register) & 0x2) == 0 &&
             i < timeout; ++i) {
                udelay(1);
        }
        if (i == timeout) {
                dev_warn(dev->class_dev,
                         "ni_pcidio: failed to load fpga %i, waiting for status 0x2\n",
                         fpga_index);
                return -EIO;
        }
        writew(0x80 | fpga_index, dev->mmio + Firmware_Control_Register);
        for (i = 0;
             readw(dev->mmio + Firmware_Status_Register) != 0x3 &&
             i < timeout; ++i) {
                udelay(1);
        }
        if (i == timeout) {
                dev_warn(dev->class_dev,
                         "ni_pcidio: failed to load fpga %i, waiting for status 0x3\n",
                         fpga_index);
                return -EIO;
        }
        for (j = 0; j + 1 < data_len;) {
                unsigned int value = data[j++];

                value |= data[j++] << 8;
                writew(value, dev->mmio + Firmware_Data_Register);
                for (i = 0;
                     (readw(dev->mmio + Firmware_Status_Register) & 0x2) == 0
                     && i < timeout; ++i) {
                        udelay(1);
                }
                if (i == timeout) {
                        dev_warn(dev->class_dev,
                                 "ni_pcidio: failed to load word into fpga %i\n",
                                 fpga_index);
                        return -EIO;
                }
                if (need_resched())
                        schedule();
        }
        writew(0x0, dev->mmio + Firmware_Control_Register);
        return 0;
}

static int pci_6534_reset_fpga(struct comedi_device *dev, int fpga_index)
{
        return pci_6534_load_fpga(dev, NULL, 0, fpga_index);
}

static int pci_6534_reset_fpgas(struct comedi_device *dev)
{
        int ret;
        int i;

        writew(0x0, dev->mmio + Firmware_Control_Register);
        for (i = 0; i < 3; ++i) {
                ret = pci_6534_reset_fpga(dev, i);
                if (ret < 0)
                        break;
        }
        writew(0x0, dev->mmio + Firmware_Mask_Register);
        return ret;
}

static void pci_6534_init_main_fpga(struct comedi_device *dev)
{
        writel(0, dev->mmio + FPGA_Control1_Register);
        writel(0, dev->mmio + FPGA_Control2_Register);
        writel(0, dev->mmio + FPGA_SCALS_Counter_Register);
        writel(0, dev->mmio + FPGA_SCAMS_Counter_Register);
        writel(0, dev->mmio + FPGA_SCBLS_Counter_Register);
        writel(0, dev->mmio + FPGA_SCBMS_Counter_Register);
}

static int pci_6534_upload_firmware(struct comedi_device *dev)
{
        struct nidio96_private *devpriv = dev->private;
        static const char *const fw_file[3] = {
                FW_PCI_6534_SCARAB_DI,  /* loaded into scarab A for DI */
                FW_PCI_6534_SCARAB_DO,  /* loaded into scarab B for DO */
                FW_PCI_6534_MAIN,       /* loaded into main FPGA */
        };
        int ret;
        int n;

        ret = pci_6534_reset_fpgas(dev);
        if (ret < 0)
                return ret;
        /* load main FPGA first, then the two scarabs */
        for (n = 2; n >= 0; n--) {
                ret = comedi_load_firmware(dev, &devpriv->mite->pcidev->dev,
                                           fw_file[n],
                                           pci_6534_load_fpga, n);
                if (ret == 0 && n == 2)
                        pci_6534_init_main_fpga(dev);
                if (ret < 0)
                        break;
        }
        return ret;
}

static void nidio_reset_board(struct comedi_device *dev)
{
        writel(0, dev->mmio + PORT_IO(0));
        writel(0, dev->mmio + PORT_PIN_DIRECTIONS(0));
        writel(0, dev->mmio + PORT_PIN_MASK(0));

        /* disable interrupts on board */
        writeb(0, dev->mmio + MASTER_DMA_AND_INTERRUPT_CONTROL);
}

static int nidio_auto_attach(struct comedi_device *dev,
                             unsigned long context)
{
        struct pci_dev *pcidev = comedi_to_pci_dev(dev);
        const struct nidio_board *board = NULL;
        struct nidio96_private *devpriv;
        struct comedi_subdevice *s;
        int ret;
        unsigned int irq;

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

        ret = comedi_pci_enable(dev);
        if (ret)
                return ret;

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

        spin_lock_init(&devpriv->mite_channel_lock);

        devpriv->mite = mite_attach(dev, false);        /* use win0 */
        if (!devpriv->mite)
                return -ENOMEM;

        devpriv->di_mite_ring = mite_alloc_ring(devpriv->mite);
        if (!devpriv->di_mite_ring)
                return -ENOMEM;

        if (board->uses_firmware) {
                ret = pci_6534_upload_firmware(dev);
                if (ret < 0)
                        return ret;
        }

        nidio_reset_board(dev);

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

        dev_info(dev->class_dev, "%s rev=%d\n", dev->board_name,
                 readb(dev->mmio + CHIP_VERSION));

        s = &dev->subdevices[0];

        dev->read_subdev = s;
        s->type = COMEDI_SUBD_DIO;
        s->subdev_flags =
                SDF_READABLE | SDF_WRITABLE | SDF_LSAMPL | SDF_PACKED |
                SDF_CMD_READ;
        s->n_chan = 32;
        s->range_table = &range_digital;
        s->maxdata = 1;
        s->insn_config = &ni_pcidio_insn_config;
        s->insn_bits = &ni_pcidio_insn_bits;
        s->do_cmd = &ni_pcidio_cmd;
        s->do_cmdtest = &ni_pcidio_cmdtest;
        s->cancel = &ni_pcidio_cancel;
        s->len_chanlist = 32;   /* XXX */
        s->buf_change = &ni_pcidio_change;
        s->async_dma_dir = DMA_BIDIRECTIONAL;
        s->poll = &ni_pcidio_poll;

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

        return 0;
}

static void nidio_detach(struct comedi_device *dev)
{
        struct nidio96_private *devpriv = dev->private;

        if (dev->irq)
                free_irq(dev->irq, dev);
        if (devpriv) {
                if (devpriv->di_mite_ring) {
                        mite_free_ring(devpriv->di_mite_ring);
                        devpriv->di_mite_ring = NULL;
                }
                mite_detach(devpriv->mite);
        }
        if (dev->mmio)
                iounmap(dev->mmio);
        comedi_pci_disable(dev);
}

static struct comedi_driver ni_pcidio_driver = {
        .driver_name    = "ni_pcidio",
        .module         = THIS_MODULE,
        .auto_attach    = nidio_auto_attach,
        .detach         = nidio_detach,
};

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

static const struct pci_device_id ni_pcidio_pci_table[] = {
        { PCI_VDEVICE(NI, 0x1150), BOARD_PCIDIO_32HS },
        { PCI_VDEVICE(NI, 0x12b0), BOARD_PCI6534 },
        { PCI_VDEVICE(NI, 0x1320), BOARD_PXI6533 },
        { 0 }
};
MODULE_DEVICE_TABLE(pci, ni_pcidio_pci_table);

static struct pci_driver ni_pcidio_pci_driver = {

        .name           = "ni_pcidio",
        .id_table       = ni_pcidio_pci_table,
        .probe          = ni_pcidio_pci_probe,
        .remove         = comedi_pci_auto_unconfig,
};
module_comedi_pci_driver(ni_pcidio_driver, ni_pcidio_pci_driver);

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