/*
  comedi/drivers/ni_660x.c
  Hardware driver for NI 660x devices

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
Driver: ni_660x
Description: National Instruments 660x counter/timer boards
Devices:
[National Instruments] PCI-6601 (ni_660x), PCI-6602, PXI-6602,
	PXI-6608
Author: J.P. Mellor <jpmellor@rose-hulman.edu>,
	Herman.Bruyninckx@mech.kuleuven.ac.be,
	Wim.Meeussen@mech.kuleuven.ac.be,
	Klaas.Gadeyne@mech.kuleuven.ac.be,
	Frank Mori Hess <fmhess@users.sourceforge.net>
Updated: Thu Oct 18 12:56:06 EDT 2007
Status: experimental

Encoders work.  PulseGeneration (both single pulse and pulse train)
works. Buffered commands work for input but not output.

References:
DAQ 660x Register-Level Programmer Manual  (NI 370505A-01)
DAQ 6601/6602 User Manual (NI 322137B-01)

*/

#include <linux/interrupt.h>
#include "../comedidev.h"
#include "mite.h"
#include "ni_tio.h"

enum ni_660x_constants {
	min_counter_pfi_chan = 8,
	max_dio_pfi_chan = 31,
	counters_per_chip = 4
};

#define NUM_PFI_CHANNELS 40
/* really there are only up to 3 dma channels, but the register layout allows
for 4 */
#define MAX_DMA_CHANNEL 4

/* See Register-Level Programmer Manual page 3.1 */
enum NI_660x_Register {
	G0InterruptAcknowledge,
	G0StatusRegister,
	G1InterruptAcknowledge,
	G1StatusRegister,
	G01StatusRegister,
	G0CommandRegister,
	STCDIOParallelInput,
	G1CommandRegister,
	G0HWSaveRegister,
	G1HWSaveRegister,
	STCDIOOutput,
	STCDIOControl,
	G0SWSaveRegister,
	G1SWSaveRegister,
	G0ModeRegister,
	G01JointStatus1Register,
	G1ModeRegister,
	STCDIOSerialInput,
	G0LoadARegister,
	G01JointStatus2Register,
	G0LoadBRegister,
	G1LoadARegister,
	G1LoadBRegister,
	G0InputSelectRegister,
	G1InputSelectRegister,
	G0AutoincrementRegister,
	G1AutoincrementRegister,
	G01JointResetRegister,
	G0InterruptEnable,
	G1InterruptEnable,
	G0CountingModeRegister,
	G1CountingModeRegister,
	G0SecondGateRegister,
	G1SecondGateRegister,
	G0DMAConfigRegister,
	G0DMAStatusRegister,
	G1DMAConfigRegister,
	G1DMAStatusRegister,
	G2InterruptAcknowledge,
	G2StatusRegister,
	G3InterruptAcknowledge,
	G3StatusRegister,
	G23StatusRegister,
	G2CommandRegister,
	G3CommandRegister,
	G2HWSaveRegister,
	G3HWSaveRegister,
	G2SWSaveRegister,
	G3SWSaveRegister,
	G2ModeRegister,
	G23JointStatus1Register,
	G3ModeRegister,
	G2LoadARegister,
	G23JointStatus2Register,
	G2LoadBRegister,
	G3LoadARegister,
	G3LoadBRegister,
	G2InputSelectRegister,
	G3InputSelectRegister,
	G2AutoincrementRegister,
	G3AutoincrementRegister,
	G23JointResetRegister,
	G2InterruptEnable,
	G3InterruptEnable,
	G2CountingModeRegister,
	G3CountingModeRegister,
	G3SecondGateRegister,
	G2SecondGateRegister,
	G2DMAConfigRegister,
	G2DMAStatusRegister,
	G3DMAConfigRegister,
	G3DMAStatusRegister,
	DIO32Input,
	DIO32Output,
	ClockConfigRegister,
	GlobalInterruptStatusRegister,
	DMAConfigRegister,
	GlobalInterruptConfigRegister,
	IOConfigReg0_1,
	IOConfigReg2_3,
	IOConfigReg4_5,
	IOConfigReg6_7,
	IOConfigReg8_9,
	IOConfigReg10_11,
	IOConfigReg12_13,
	IOConfigReg14_15,
	IOConfigReg16_17,
	IOConfigReg18_19,
	IOConfigReg20_21,
	IOConfigReg22_23,
	IOConfigReg24_25,
	IOConfigReg26_27,
	IOConfigReg28_29,
	IOConfigReg30_31,
	IOConfigReg32_33,
	IOConfigReg34_35,
	IOConfigReg36_37,
	IOConfigReg38_39,
	NumRegisters,
};

static inline unsigned IOConfigReg(unsigned pfi_channel)
{
	unsigned reg = IOConfigReg0_1 + pfi_channel / 2;
	BUG_ON(reg > IOConfigReg38_39);
	return reg;
}

enum ni_660x_register_width {
	DATA_1B,
	DATA_2B,
	DATA_4B
};

enum ni_660x_register_direction {
	NI_660x_READ,
	NI_660x_WRITE,
	NI_660x_READ_WRITE
};

enum ni_660x_pfi_output_select {
	pfi_output_select_high_Z = 0,
	pfi_output_select_counter = 1,
	pfi_output_select_do = 2,
	num_pfi_output_selects
};

enum ni_660x_subdevices {
	NI_660X_DIO_SUBDEV = 1,
	NI_660X_GPCT_SUBDEV_0 = 2
};
static inline unsigned NI_660X_GPCT_SUBDEV(unsigned index)
{
	return NI_660X_GPCT_SUBDEV_0 + index;
}

struct NI_660xRegisterData {

	const char *name;	/*  Register Name */
	int offset;		/*  Offset from base address from GPCT chip */
	enum ni_660x_register_direction direction;
	enum ni_660x_register_width size; /* 1 byte, 2 bytes, or 4 bytes */
};

static const struct NI_660xRegisterData registerData[NumRegisters] = {
	{"G0 Interrupt Acknowledge", 0x004, NI_660x_WRITE, DATA_2B},
	{"G0 Status Register", 0x004, NI_660x_READ, DATA_2B},
	{"G1 Interrupt Acknowledge", 0x006, NI_660x_WRITE, DATA_2B},
	{"G1 Status Register", 0x006, NI_660x_READ, DATA_2B},
	{"G01 Status Register ", 0x008, NI_660x_READ, DATA_2B},
	{"G0 Command Register", 0x00C, NI_660x_WRITE, DATA_2B},
	{"STC DIO Parallel Input", 0x00E, NI_660x_READ, DATA_2B},
	{"G1 Command Register", 0x00E, NI_660x_WRITE, DATA_2B},
	{"G0 HW Save Register", 0x010, NI_660x_READ, DATA_4B},
	{"G1 HW Save Register", 0x014, NI_660x_READ, DATA_4B},
	{"STC DIO Output", 0x014, NI_660x_WRITE, DATA_2B},
	{"STC DIO Control", 0x016, NI_660x_WRITE, DATA_2B},
	{"G0 SW Save Register", 0x018, NI_660x_READ, DATA_4B},
	{"G1 SW Save Register", 0x01C, NI_660x_READ, DATA_4B},
	{"G0 Mode Register", 0x034, NI_660x_WRITE, DATA_2B},
	{"G01 Joint Status 1 Register", 0x036, NI_660x_READ, DATA_2B},
	{"G1 Mode Register", 0x036, NI_660x_WRITE, DATA_2B},
	{"STC DIO Serial Input", 0x038, NI_660x_READ, DATA_2B},
	{"G0 Load A Register", 0x038, NI_660x_WRITE, DATA_4B},
	{"G01 Joint Status 2 Register", 0x03A, NI_660x_READ, DATA_2B},
	{"G0 Load B Register", 0x03C, NI_660x_WRITE, DATA_4B},
	{"G1 Load A Register", 0x040, NI_660x_WRITE, DATA_4B},
	{"G1 Load B Register", 0x044, NI_660x_WRITE, DATA_4B},
	{"G0 Input Select Register", 0x048, NI_660x_WRITE, DATA_2B},
	{"G1 Input Select Register", 0x04A, NI_660x_WRITE, DATA_2B},
	{"G0 Autoincrement Register", 0x088, NI_660x_WRITE, DATA_2B},
	{"G1 Autoincrement Register", 0x08A, NI_660x_WRITE, DATA_2B},
	{"G01 Joint Reset Register", 0x090, NI_660x_WRITE, DATA_2B},
	{"G0 Interrupt Enable", 0x092, NI_660x_WRITE, DATA_2B},
	{"G1 Interrupt Enable", 0x096, NI_660x_WRITE, DATA_2B},
	{"G0 Counting Mode Register", 0x0B0, NI_660x_WRITE, DATA_2B},
	{"G1 Counting Mode Register", 0x0B2, NI_660x_WRITE, DATA_2B},
	{"G0 Second Gate Register", 0x0B4, NI_660x_WRITE, DATA_2B},
	{"G1 Second Gate Register", 0x0B6, NI_660x_WRITE, DATA_2B},
	{"G0 DMA Config Register", 0x0B8, NI_660x_WRITE, DATA_2B},
	{"G0 DMA Status Register", 0x0B8, NI_660x_READ, DATA_2B},
	{"G1 DMA Config Register", 0x0BA, NI_660x_WRITE, DATA_2B},
	{"G1 DMA Status Register", 0x0BA, NI_660x_READ, DATA_2B},
	{"G2 Interrupt Acknowledge", 0x104, NI_660x_WRITE, DATA_2B},
	{"G2 Status Register", 0x104, NI_660x_READ, DATA_2B},
	{"G3 Interrupt Acknowledge", 0x106, NI_660x_WRITE, DATA_2B},
	{"G3 Status Register", 0x106, NI_660x_READ, DATA_2B},
	{"G23 Status Register", 0x108, NI_660x_READ, DATA_2B},
	{"G2 Command Register", 0x10C, NI_660x_WRITE, DATA_2B},
	{"G3 Command Register", 0x10E, NI_660x_WRITE, DATA_2B},
	{"G2 HW Save Register", 0x110, NI_660x_READ, DATA_4B},
	{"G3 HW Save Register", 0x114, NI_660x_READ, DATA_4B},
	{"G2 SW Save Register", 0x118, NI_660x_READ, DATA_4B},
	{"G3 SW Save Register", 0x11C, NI_660x_READ, DATA_4B},
	{"G2 Mode Register", 0x134, NI_660x_WRITE, DATA_2B},
	{"G23 Joint Status 1 Register", 0x136, NI_660x_READ, DATA_2B},
	{"G3 Mode Register", 0x136, NI_660x_WRITE, DATA_2B},
	{"G2 Load A Register", 0x138, NI_660x_WRITE, DATA_4B},
	{"G23 Joint Status 2 Register", 0x13A, NI_660x_READ, DATA_2B},
	{"G2 Load B Register", 0x13C, NI_660x_WRITE, DATA_4B},
	{"G3 Load A Register", 0x140, NI_660x_WRITE, DATA_4B},
	{"G3 Load B Register", 0x144, NI_660x_WRITE, DATA_4B},
	{"G2 Input Select Register", 0x148, NI_660x_WRITE, DATA_2B},
	{"G3 Input Select Register", 0x14A, NI_660x_WRITE, DATA_2B},
	{"G2 Autoincrement Register", 0x188, NI_660x_WRITE, DATA_2B},
	{"G3 Autoincrement Register", 0x18A, NI_660x_WRITE, DATA_2B},
	{"G23 Joint Reset Register", 0x190, NI_660x_WRITE, DATA_2B},
	{"G2 Interrupt Enable", 0x192, NI_660x_WRITE, DATA_2B},
	{"G3 Interrupt Enable", 0x196, NI_660x_WRITE, DATA_2B},
	{"G2 Counting Mode Register", 0x1B0, NI_660x_WRITE, DATA_2B},
	{"G3 Counting Mode Register", 0x1B2, NI_660x_WRITE, DATA_2B},
	{"G3 Second Gate Register", 0x1B6, NI_660x_WRITE, DATA_2B},
	{"G2 Second Gate Register", 0x1B4, NI_660x_WRITE, DATA_2B},
	{"G2 DMA Config Register", 0x1B8, NI_660x_WRITE, DATA_2B},
	{"G2 DMA Status Register", 0x1B8, NI_660x_READ, DATA_2B},
	{"G3 DMA Config Register", 0x1BA, NI_660x_WRITE, DATA_2B},
	{"G3 DMA Status Register", 0x1BA, NI_660x_READ, DATA_2B},
	{"32 bit Digital Input", 0x414, NI_660x_READ, DATA_4B},
	{"32 bit Digital Output", 0x510, NI_660x_WRITE, DATA_4B},
	{"Clock Config Register", 0x73C, NI_660x_WRITE, DATA_4B},
	{"Global Interrupt Status Register", 0x754, NI_660x_READ, DATA_4B},
	{"DMA Configuration Register", 0x76C, NI_660x_WRITE, DATA_4B},
	{"Global Interrupt Config Register", 0x770, NI_660x_WRITE, DATA_4B},
	{"IO Config Register 0-1", 0x77C, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 2-3", 0x77E, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 4-5", 0x780, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 6-7", 0x782, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 8-9", 0x784, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 10-11", 0x786, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 12-13", 0x788, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 14-15", 0x78A, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 16-17", 0x78C, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 18-19", 0x78E, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 20-21", 0x790, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 22-23", 0x792, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 24-25", 0x794, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 26-27", 0x796, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 28-29", 0x798, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 30-31", 0x79A, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 32-33", 0x79C, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 34-35", 0x79E, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 36-37", 0x7A0, NI_660x_READ_WRITE, DATA_2B},
	{"IO Config Register 38-39", 0x7A2, NI_660x_READ_WRITE, DATA_2B}
};

/* kind of ENABLE for the second counter */
enum clock_config_register_bits {
	CounterSwap = 0x1 << 21
};

/* ioconfigreg */
static inline unsigned ioconfig_bitshift(unsigned pfi_channel)
{
	if (pfi_channel % 2)
		return 0;
	else
		return 8;
}

static inline unsigned pfi_output_select_mask(unsigned pfi_channel)
{
	return 0x3 << ioconfig_bitshift(pfi_channel);
}

static inline unsigned pfi_output_select_bits(unsigned pfi_channel,
					      unsigned output_select)
{
	return (output_select & 0x3) << ioconfig_bitshift(pfi_channel);
}

static inline unsigned pfi_input_select_mask(unsigned pfi_channel)
{
	return 0x7 << (4 + ioconfig_bitshift(pfi_channel));
}

static inline unsigned pfi_input_select_bits(unsigned pfi_channel,
					     unsigned input_select)
{
	return (input_select & 0x7) << (4 + ioconfig_bitshift(pfi_channel));
}

/* dma configuration register bits */
static inline unsigned dma_select_mask(unsigned dma_channel)
{
	BUG_ON(dma_channel >= MAX_DMA_CHANNEL);
	return 0x1f << (8 * dma_channel);
}

enum dma_selection {
	dma_selection_none = 0x1f,
};
static inline unsigned dma_selection_counter(unsigned counter_index)
{
	BUG_ON(counter_index >= counters_per_chip);
	return counter_index;
}

static inline unsigned dma_select_bits(unsigned dma_channel, unsigned selection)
{
	BUG_ON(dma_channel >= MAX_DMA_CHANNEL);
	return (selection << (8 * dma_channel)) & dma_select_mask(dma_channel);
}

static inline unsigned dma_reset_bit(unsigned dma_channel)
{
	BUG_ON(dma_channel >= MAX_DMA_CHANNEL);
	return 0x80 << (8 * dma_channel);
}

enum global_interrupt_status_register_bits {
	Counter_0_Int_Bit = 0x100,
	Counter_1_Int_Bit = 0x200,
	Counter_2_Int_Bit = 0x400,
	Counter_3_Int_Bit = 0x800,
	Cascade_Int_Bit = 0x20000000,
	Global_Int_Bit = 0x80000000
};

enum global_interrupt_config_register_bits {
	Cascade_Int_Enable_Bit = 0x20000000,
	Global_Int_Polarity_Bit = 0x40000000,
	Global_Int_Enable_Bit = 0x80000000
};

/* Offset of the GPCT chips from the base-adress of the card */
/* First chip is at base-address + 0x00, etc. */
static const unsigned GPCT_OFFSET[2] = { 0x0, 0x800 };

/* Board description*/
struct ni_660x_board {
	unsigned short dev_id;	/* `lspci` will show you this */
	const char *name;
	unsigned n_chips;	/* total number of TIO chips */
};

static const struct ni_660x_board ni_660x_boards[] = {
	{
	 .dev_id = 0x2c60,
	 .name = "PCI-6601",
	 .n_chips = 1,
	 },
	{
	 .dev_id = 0x1310,
	 .name = "PCI-6602",
	 .n_chips = 2,
	 },
	{
	 .dev_id = 0x1360,
	 .name = "PXI-6602",
	 .n_chips = 2,
	 },
	{
	 .dev_id = 0x2cc0,
	 .name = "PXI-6608",
	 .n_chips = 2,
	 },
};

#define NI_660X_MAX_NUM_CHIPS 2
#define NI_660X_MAX_NUM_COUNTERS (NI_660X_MAX_NUM_CHIPS * counters_per_chip)

static DEFINE_PCI_DEVICE_TABLE(ni_660x_pci_table) = {
	{PCI_DEVICE(PCI_VENDOR_ID_NI, 0x2c60)},
	{PCI_DEVICE(PCI_VENDOR_ID_NI, 0x1310)},
	{PCI_DEVICE(PCI_VENDOR_ID_NI, 0x1360)},
	{PCI_DEVICE(PCI_VENDOR_ID_NI, 0x2cc0)},
	{0}
};

MODULE_DEVICE_TABLE(pci, ni_660x_pci_table);

struct ni_660x_private {
	struct mite_struct *mite;
	struct ni_gpct_device *counter_dev;
	uint64_t pfi_direction_bits;
	struct mite_dma_descriptor_ring
	*mite_rings[NI_660X_MAX_NUM_CHIPS][counters_per_chip];
	spinlock_t mite_channel_lock;
	/* interrupt_lock prevents races between interrupt and comedi_poll */
	spinlock_t interrupt_lock;
	unsigned dma_configuration_soft_copies[NI_660X_MAX_NUM_CHIPS];
	spinlock_t soft_reg_copy_lock;
	unsigned short pfi_output_selects[NUM_PFI_CHANNELS];
};

static inline struct ni_660x_private *private(struct comedi_device *dev)
{
	return dev->private;
}

/* initialized in ni_660x_find_device() */
static inline const struct ni_660x_board *board(struct comedi_device *dev)
{
	return dev->board_ptr;
}

#define n_ni_660x_boards ARRAY_SIZE(ni_660x_boards)

static int ni_660x_attach(struct comedi_device *dev,
			  struct comedi_devconfig *it);
static int ni_660x_detach(struct comedi_device *dev);
static void init_tio_chip(struct comedi_device *dev, int chipset);
static void ni_660x_select_pfi_output(struct comedi_device *dev,
				      unsigned pfi_channel,
				      unsigned output_select);

static struct comedi_driver driver_ni_660x = {
	.driver_name = "ni_660x",
	.module = THIS_MODULE,
	.attach = ni_660x_attach,
	.detach = ni_660x_detach,
};

COMEDI_PCI_INITCLEANUP(driver_ni_660x, ni_660x_pci_table);

static int ni_660x_find_device(struct comedi_device *dev, int bus, int slot);
static int ni_660x_set_pfi_routing(struct comedi_device *dev, unsigned chan,
				   unsigned source);

/* Possible instructions for a GPCT */
static int ni_660x_GPCT_rinsn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data);
static int ni_660x_GPCT_insn_config(struct comedi_device *dev,
				    struct comedi_subdevice *s,
				    struct comedi_insn *insn,
				    unsigned int *data);
static int ni_660x_GPCT_winsn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data);

/* Possible instructions for Digital IO */
static int ni_660x_dio_insn_config(struct comedi_device *dev,
				   struct comedi_subdevice *s,
				   struct comedi_insn *insn,
				   unsigned int *data);
static int ni_660x_dio_insn_bits(struct comedi_device *dev,
				 struct comedi_subdevice *s,
				 struct comedi_insn *insn, unsigned int *data);

static inline unsigned ni_660x_num_counters(struct comedi_device *dev)
{
	return board(dev)->n_chips * counters_per_chip;
}

static enum NI_660x_Register ni_gpct_to_660x_register(enum ni_gpct_register reg)
{
	enum NI_660x_Register ni_660x_register;
	switch (reg) {
	case NITIO_G0_Autoincrement_Reg:
		ni_660x_register = G0AutoincrementRegister;
		break;
	case NITIO_G1_Autoincrement_Reg:
		ni_660x_register = G1AutoincrementRegister;
		break;
	case NITIO_G2_Autoincrement_Reg:
		ni_660x_register = G2AutoincrementRegister;
		break;
	case NITIO_G3_Autoincrement_Reg:
		ni_660x_register = G3AutoincrementRegister;
		break;
	case NITIO_G0_Command_Reg:
		ni_660x_register = G0CommandRegister;
		break;
	case NITIO_G1_Command_Reg:
		ni_660x_register = G1CommandRegister;
		break;
	case NITIO_G2_Command_Reg:
		ni_660x_register = G2CommandRegister;
		break;
	case NITIO_G3_Command_Reg:
		ni_660x_register = G3CommandRegister;
		break;
	case NITIO_G0_HW_Save_Reg:
		ni_660x_register = G0HWSaveRegister;
		break;
	case NITIO_G1_HW_Save_Reg:
		ni_660x_register = G1HWSaveRegister;
		break;
	case NITIO_G2_HW_Save_Reg:
		ni_660x_register = G2HWSaveRegister;
		break;
	case NITIO_G3_HW_Save_Reg:
		ni_660x_register = G3HWSaveRegister;
		break;
	case NITIO_G0_SW_Save_Reg:
		ni_660x_register = G0SWSaveRegister;
		break;
	case NITIO_G1_SW_Save_Reg:
		ni_660x_register = G1SWSaveRegister;
		break;
	case NITIO_G2_SW_Save_Reg:
		ni_660x_register = G2SWSaveRegister;
		break;
	case NITIO_G3_SW_Save_Reg:
		ni_660x_register = G3SWSaveRegister;
		break;
	case NITIO_G0_Mode_Reg:
		ni_660x_register = G0ModeRegister;
		break;
	case NITIO_G1_Mode_Reg:
		ni_660x_register = G1ModeRegister;
		break;
	case NITIO_G2_Mode_Reg:
		ni_660x_register = G2ModeRegister;
		break;
	case NITIO_G3_Mode_Reg:
		ni_660x_register = G3ModeRegister;
		break;
	case NITIO_G0_LoadA_Reg:
		ni_660x_register = G0LoadARegister;
		break;
	case NITIO_G1_LoadA_Reg:
		ni_660x_register = G1LoadARegister;
		break;
	case NITIO_G2_LoadA_Reg:
		ni_660x_register = G2LoadARegister;
		break;
	case NITIO_G3_LoadA_Reg:
		ni_660x_register = G3LoadARegister;
		break;
	case NITIO_G0_LoadB_Reg:
		ni_660x_register = G0LoadBRegister;
		break;
	case NITIO_G1_LoadB_Reg:
		ni_660x_register = G1LoadBRegister;
		break;
	case NITIO_G2_LoadB_Reg:
		ni_660x_register = G2LoadBRegister;
		break;
	case NITIO_G3_LoadB_Reg:
		ni_660x_register = G3LoadBRegister;
		break;
	case NITIO_G0_Input_Select_Reg:
		ni_660x_register = G0InputSelectRegister;
		break;
	case NITIO_G1_Input_Select_Reg:
		ni_660x_register = G1InputSelectRegister;
		break;
	case NITIO_G2_Input_Select_Reg:
		ni_660x_register = G2InputSelectRegister;
		break;
	case NITIO_G3_Input_Select_Reg:
		ni_660x_register = G3InputSelectRegister;
		break;
	case NITIO_G01_Status_Reg:
		ni_660x_register = G01StatusRegister;
		break;
	case NITIO_G23_Status_Reg:
		ni_660x_register = G23StatusRegister;
		break;
	case NITIO_G01_Joint_Reset_Reg:
		ni_660x_register = G01JointResetRegister;
		break;
	case NITIO_G23_Joint_Reset_Reg:
		ni_660x_register = G23JointResetRegister;
		break;
	case NITIO_G01_Joint_Status1_Reg:
		ni_660x_register = G01JointStatus1Register;
		break;
	case NITIO_G23_Joint_Status1_Reg:
		ni_660x_register = G23JointStatus1Register;
		break;
	case NITIO_G01_Joint_Status2_Reg:
		ni_660x_register = G01JointStatus2Register;
		break;
	case NITIO_G23_Joint_Status2_Reg:
		ni_660x_register = G23JointStatus2Register;
		break;
	case NITIO_G0_Counting_Mode_Reg:
		ni_660x_register = G0CountingModeRegister;
		break;
	case NITIO_G1_Counting_Mode_Reg:
		ni_660x_register = G1CountingModeRegister;
		break;
	case NITIO_G2_Counting_Mode_Reg:
		ni_660x_register = G2CountingModeRegister;
		break;
	case NITIO_G3_Counting_Mode_Reg:
		ni_660x_register = G3CountingModeRegister;
		break;
	case NITIO_G0_Second_Gate_Reg:
		ni_660x_register = G0SecondGateRegister;
		break;
	case NITIO_G1_Second_Gate_Reg:
		ni_660x_register = G1SecondGateRegister;
		break;
	case NITIO_G2_Second_Gate_Reg:
		ni_660x_register = G2SecondGateRegister;
		break;
	case NITIO_G3_Second_Gate_Reg:
		ni_660x_register = G3SecondGateRegister;
		break;
	case NITIO_G0_DMA_Config_Reg:
		ni_660x_register = G0DMAConfigRegister;
		break;
	case NITIO_G0_DMA_Status_Reg:
		ni_660x_register = G0DMAStatusRegister;
		break;
	case NITIO_G1_DMA_Config_Reg:
		ni_660x_register = G1DMAConfigRegister;
		break;
	case NITIO_G1_DMA_Status_Reg:
		ni_660x_register = G1DMAStatusRegister;
		break;
	case NITIO_G2_DMA_Config_Reg:
		ni_660x_register = G2DMAConfigRegister;
		break;
	case NITIO_G2_DMA_Status_Reg:
		ni_660x_register = G2DMAStatusRegister;
		break;
	case NITIO_G3_DMA_Config_Reg:
		ni_660x_register = G3DMAConfigRegister;
		break;
	case NITIO_G3_DMA_Status_Reg:
		ni_660x_register = G3DMAStatusRegister;
		break;
	case NITIO_G0_Interrupt_Acknowledge_Reg:
		ni_660x_register = G0InterruptAcknowledge;
		break;
	case NITIO_G1_Interrupt_Acknowledge_Reg:
		ni_660x_register = G1InterruptAcknowledge;
		break;
	case NITIO_G2_Interrupt_Acknowledge_Reg:
		ni_660x_register = G2InterruptAcknowledge;
		break;
	case NITIO_G3_Interrupt_Acknowledge_Reg:
		ni_660x_register = G3InterruptAcknowledge;
		break;
	case NITIO_G0_Status_Reg:
		ni_660x_register = G0StatusRegister;
		break;
	case NITIO_G1_Status_Reg:
		ni_660x_register = G1StatusRegister;
		break;
	case NITIO_G2_Status_Reg:
		ni_660x_register = G2StatusRegister;
		break;
	case NITIO_G3_Status_Reg:
		ni_660x_register = G3StatusRegister;
		break;
	case NITIO_G0_Interrupt_Enable_Reg:
		ni_660x_register = G0InterruptEnable;
		break;
	case NITIO_G1_Interrupt_Enable_Reg:
		ni_660x_register = G1InterruptEnable;
		break;
	case NITIO_G2_Interrupt_Enable_Reg:
		ni_660x_register = G2InterruptEnable;
		break;
	case NITIO_G3_Interrupt_Enable_Reg:
		ni_660x_register = G3InterruptEnable;
		break;
	default:
		printk(KERN_WARNING "%s: unhandled register 0x%x in switch.\n",
		       __func__, reg);
		BUG();
		return 0;
		break;
	}
	return ni_660x_register;
}

static inline void ni_660x_write_register(struct comedi_device *dev,
					  unsigned chip_index, unsigned bits,
					  enum NI_660x_Register reg)
{
	void *const write_address =
	    private(dev)->mite->daq_io_addr + GPCT_OFFSET[chip_index] +
	    registerData[reg].offset;

	switch (registerData[reg].size) {
	case DATA_2B:
		writew(bits, write_address);
		break;
	case DATA_4B:
		writel(bits, write_address);
		break;
	default:
		printk(KERN_WARNING "%s: %s: bug! unhandled case (reg=0x%x) in switch.\n",
		       __FILE__, __func__, reg);
		BUG();
		break;
	}
}

static inline unsigned ni_660x_read_register(struct comedi_device *dev,
					     unsigned chip_index,
					     enum NI_660x_Register reg)
{
	void *const read_address =
	    private(dev)->mite->daq_io_addr + GPCT_OFFSET[chip_index] +
	    registerData[reg].offset;

	switch (registerData[reg].size) {
	case DATA_2B:
		return readw(read_address);
		break;
	case DATA_4B:
		return readl(read_address);
		break;
	default:
		printk(KERN_WARNING "%s: %s: bug! unhandled case (reg=0x%x) in switch.\n",
		       __FILE__, __func__, reg);
		BUG();
		break;
	}
	return 0;
}

static void ni_gpct_write_register(struct ni_gpct *counter, unsigned bits,
				   enum ni_gpct_register reg)
{
	struct comedi_device *dev = counter->counter_dev->dev;
	enum NI_660x_Register ni_660x_register = ni_gpct_to_660x_register(reg);
	ni_660x_write_register(dev, counter->chip_index, bits,
			       ni_660x_register);
}

static unsigned ni_gpct_read_register(struct ni_gpct *counter,
				      enum ni_gpct_register reg)
{
	struct comedi_device *dev = counter->counter_dev->dev;
	enum NI_660x_Register ni_660x_register = ni_gpct_to_660x_register(reg);
	return ni_660x_read_register(dev, counter->chip_index,
				     ni_660x_register);
}

static inline struct mite_dma_descriptor_ring *mite_ring(struct ni_660x_private
							 *priv,
							 struct ni_gpct
							 *counter)
{
	return priv->mite_rings[counter->chip_index][counter->counter_index];
}

static inline void ni_660x_set_dma_channel(struct comedi_device *dev,
					   unsigned mite_channel,
					   struct ni_gpct *counter)
{
	unsigned long flags;
	spin_lock_irqsave(&private(dev)->soft_reg_copy_lock, flags);
	private(dev)->dma_configuration_soft_copies[counter->chip_index] &=
	    ~dma_select_mask(mite_channel);
	private(dev)->dma_configuration_soft_copies[counter->chip_index] |=
	    dma_select_bits(mite_channel,
			    dma_selection_counter(counter->counter_index));
	ni_660x_write_register(dev, counter->chip_index,
			       private(dev)->
			       dma_configuration_soft_copies
			       [counter->chip_index] |
			       dma_reset_bit(mite_channel), DMAConfigRegister);
	mmiowb();
	spin_unlock_irqrestore(&private(dev)->soft_reg_copy_lock, flags);
}

static inline void ni_660x_unset_dma_channel(struct comedi_device *dev,
					     unsigned mite_channel,
					     struct ni_gpct *counter)
{
	unsigned long flags;
	spin_lock_irqsave(&private(dev)->soft_reg_copy_lock, flags);
	private(dev)->dma_configuration_soft_copies[counter->chip_index] &=
	    ~dma_select_mask(mite_channel);
	private(dev)->dma_configuration_soft_copies[counter->chip_index] |=
	    dma_select_bits(mite_channel, dma_selection_none);
	ni_660x_write_register(dev, counter->chip_index,
			       private(dev)->
			       dma_configuration_soft_copies
			       [counter->chip_index], DMAConfigRegister);
	mmiowb();
	spin_unlock_irqrestore(&private(dev)->soft_reg_copy_lock, flags);
}

static int ni_660x_request_mite_channel(struct comedi_device *dev,
					struct ni_gpct *counter,
					enum comedi_io_direction direction)
{
	unsigned long flags;
	struct mite_channel *mite_chan;

	spin_lock_irqsave(&private(dev)->mite_channel_lock, flags);
	BUG_ON(counter->mite_chan);
	mite_chan =
	    mite_request_channel(private(dev)->mite, mite_ring(private(dev),
							       counter));
	if (mite_chan == NULL) {
		spin_unlock_irqrestore(&private(dev)->mite_channel_lock, flags);
		comedi_error(dev,
			     "failed to reserve mite dma channel for counter.");
		return -EBUSY;
	}
	mite_chan->dir = direction;
	ni_tio_set_mite_channel(counter, mite_chan);
	ni_660x_set_dma_channel(dev, mite_chan->channel, counter);
	spin_unlock_irqrestore(&private(dev)->mite_channel_lock, flags);
	return 0;
}

void ni_660x_release_mite_channel(struct comedi_device *dev,
				  struct ni_gpct *counter)
{
	unsigned long flags;

	spin_lock_irqsave(&private(dev)->mite_channel_lock, flags);
	if (counter->mite_chan) {
		struct mite_channel *mite_chan = counter->mite_chan;

		ni_660x_unset_dma_channel(dev, mite_chan->channel, counter);
		ni_tio_set_mite_channel(counter, NULL);
		mite_release_channel(mite_chan);
	}
	spin_unlock_irqrestore(&private(dev)->mite_channel_lock, flags);
}

static int ni_660x_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
	int retval;

	struct ni_gpct *counter = subdev_to_counter(s);
/* const struct comedi_cmd *cmd = &s->async->cmd; */

	retval = ni_660x_request_mite_channel(dev, counter, COMEDI_INPUT);
	if (retval) {
		comedi_error(dev,
			     "no dma channel available for use by counter");
		return retval;
	}
	ni_tio_acknowledge_and_confirm(counter, NULL, NULL, NULL, NULL);
	retval = ni_tio_cmd(counter, s->async);

	return retval;
}

static int ni_660x_cmdtest(struct comedi_device *dev,
			   struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
	struct ni_gpct *counter = subdev_to_counter(s);

	return ni_tio_cmdtest(counter, cmd);
}

static int ni_660x_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
{
	struct ni_gpct *counter = subdev_to_counter(s);
	int retval;

	retval = ni_tio_cancel(counter);
	ni_660x_release_mite_channel(dev, counter);
	return retval;
}

static void set_tio_counterswap(struct comedi_device *dev, int chipset)
{
	/* See P. 3.5 of the Register-Level Programming manual.  The
	   CounterSwap bit has to be set on the second chip, otherwise
	   it will try to use the same pins as the first chip.
	 */
	if (chipset)
		ni_660x_write_register(dev, chipset, CounterSwap,
				       ClockConfigRegister);
	else
		ni_660x_write_register(dev, chipset, 0, ClockConfigRegister);
}

static void ni_660x_handle_gpct_interrupt(struct comedi_device *dev,
					  struct comedi_subdevice *s)
{
	ni_tio_handle_interrupt(subdev_to_counter(s), s);
	if (s->async->events) {
		if (s->async->events & (COMEDI_CB_EOA | COMEDI_CB_ERROR |
					COMEDI_CB_OVERFLOW)) {
			ni_660x_cancel(dev, s);
		}
		comedi_event(dev, s);
	}
}

static irqreturn_t ni_660x_interrupt(int irq, void *d)
{
	struct comedi_device *dev = d;
	struct comedi_subdevice *s;
	unsigned i;
	unsigned long flags;

	if (dev->attached == 0)
		return IRQ_NONE;
	/* lock to avoid race with comedi_poll */
	spin_lock_irqsave(&private(dev)->interrupt_lock, flags);
	smp_mb();
	for (i = 0; i < ni_660x_num_counters(dev); ++i) {
		s = dev->subdevices + NI_660X_GPCT_SUBDEV(i);
		ni_660x_handle_gpct_interrupt(dev, s);
	}
	spin_unlock_irqrestore(&private(dev)->interrupt_lock, flags);
	return IRQ_HANDLED;
}

static int ni_660x_input_poll(struct comedi_device *dev,
			      struct comedi_subdevice *s)
{
	unsigned long flags;
	/* lock to avoid race with comedi_poll */
	spin_lock_irqsave(&private(dev)->interrupt_lock, flags);
	mite_sync_input_dma(subdev_to_counter(s)->mite_chan, s->async);
	spin_unlock_irqrestore(&private(dev)->interrupt_lock, flags);
	return comedi_buf_read_n_available(s->async);
}

static int ni_660x_buf_change(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      unsigned long new_size)
{
	int ret;

	ret = mite_buf_change(mite_ring(private(dev), subdev_to_counter(s)),
			      s->async);
	if (ret < 0)
		return ret;

	return 0;
}

static int ni_660x_allocate_private(struct comedi_device *dev)
{
	int retval;
	unsigned i;

	retval = alloc_private(dev, sizeof(struct ni_660x_private));
	if (retval < 0)
		return retval;

	spin_lock_init(&private(dev)->mite_channel_lock);
	spin_lock_init(&private(dev)->interrupt_lock);
	spin_lock_init(&private(dev)->soft_reg_copy_lock);
	for (i = 0; i < NUM_PFI_CHANNELS; ++i)
		private(dev)->pfi_output_selects[i] = pfi_output_select_counter;

	return 0;
}

static int ni_660x_alloc_mite_rings(struct comedi_device *dev)
{
	unsigned i;
	unsigned j;

	for (i = 0; i < board(dev)->n_chips; ++i) {
		for (j = 0; j < counters_per_chip; ++j) {
			private(dev)->mite_rings[i][j] =
			    mite_alloc_ring(private(dev)->mite);
			if (private(dev)->mite_rings[i][j] == NULL)
				return -ENOMEM;
		}
	}
	return 0;
}

static void ni_660x_free_mite_rings(struct comedi_device *dev)
{
	unsigned i;
	unsigned j;

	for (i = 0; i < board(dev)->n_chips; ++i) {
		for (j = 0; j < counters_per_chip; ++j)
			mite_free_ring(private(dev)->mite_rings[i][j]);
	}
}

static int ni_660x_attach(struct comedi_device *dev,
			  struct comedi_devconfig *it)
{
	struct comedi_subdevice *s;
	int ret;
	unsigned i;
	unsigned global_interrupt_config_bits;

	printk(KERN_INFO "comedi%d: ni_660x: ", dev->minor);

	ret = ni_660x_allocate_private(dev);
	if (ret < 0)
		return ret;
	ret = ni_660x_find_device(dev, it->options[0], it->options[1]);
	if (ret < 0)
		return ret;

	dev->board_name = board(dev)->name;

	ret = mite_setup2(private(dev)->mite, 1);
	if (ret < 0) {
		printk(KERN_WARNING "error setting up mite\n");
		return ret;
	}
	comedi_set_hw_dev(dev, &private(dev)->mite->pcidev->dev);
	ret = ni_660x_alloc_mite_rings(dev);
	if (ret < 0)
		return ret;

	printk(KERN_INFO " %s ", dev->board_name);

	dev->n_subdevices = 2 + NI_660X_MAX_NUM_COUNTERS;

	if (alloc_subdevices(dev, dev->n_subdevices) < 0)
		return -ENOMEM;

	s = dev->subdevices + 0;
	/* Old GENERAL-PURPOSE COUNTER/TIME (GPCT) subdevice, no longer used */
	s->type = COMEDI_SUBD_UNUSED;

	s = dev->subdevices + NI_660X_DIO_SUBDEV;
	/* DIGITAL I/O SUBDEVICE */
	s->type = COMEDI_SUBD_DIO;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
	s->n_chan = NUM_PFI_CHANNELS;
	s->maxdata = 1;
	s->range_table = &range_digital;
	s->insn_bits = ni_660x_dio_insn_bits;
	s->insn_config = ni_660x_dio_insn_config;
	s->io_bits = 0;		/* all bits default to input */
	/*  we use the ioconfig registers to control dio direction, so zero
	output enables in stc dio control reg */
	ni_660x_write_register(dev, 0, 0, STCDIOControl);

	private(dev)->counter_dev = ni_gpct_device_construct(dev,
						     &ni_gpct_write_register,
						     &ni_gpct_read_register,
						     ni_gpct_variant_660x,
						     ni_660x_num_counters
						     (dev));
	if (private(dev)->counter_dev == NULL)
		return -ENOMEM;
	for (i = 0; i < NI_660X_MAX_NUM_COUNTERS; ++i) {
		s = dev->subdevices + NI_660X_GPCT_SUBDEV(i);
		if (i < ni_660x_num_counters(dev)) {
			s->type = COMEDI_SUBD_COUNTER;
			s->subdev_flags =
			    SDF_READABLE | SDF_WRITABLE | SDF_LSAMPL |
			    SDF_CMD_READ /* | SDF_CMD_WRITE */ ;
			s->n_chan = 3;
			s->maxdata = 0xffffffff;
			s->insn_read = ni_660x_GPCT_rinsn;
			s->insn_write = ni_660x_GPCT_winsn;
			s->insn_config = ni_660x_GPCT_insn_config;
			s->do_cmd = &ni_660x_cmd;
			s->len_chanlist = 1;
			s->do_cmdtest = &ni_660x_cmdtest;
			s->cancel = &ni_660x_cancel;
			s->poll = &ni_660x_input_poll;
			s->async_dma_dir = DMA_BIDIRECTIONAL;
			s->buf_change = &ni_660x_buf_change;
			s->private = &private(dev)->counter_dev->counters[i];

			private(dev)->counter_dev->counters[i].chip_index =
			    i / counters_per_chip;
			private(dev)->counter_dev->counters[i].counter_index =
			    i % counters_per_chip;
		} else {
			s->type = COMEDI_SUBD_UNUSED;
		}
	}
	for (i = 0; i < board(dev)->n_chips; ++i)
		init_tio_chip(dev, i);

	for (i = 0; i < ni_660x_num_counters(dev); ++i)
		ni_tio_init_counter(&private(dev)->counter_dev->counters[i]);

	for (i = 0; i < NUM_PFI_CHANNELS; ++i) {
		if (i < min_counter_pfi_chan)
			ni_660x_set_pfi_routing(dev, i, pfi_output_select_do);
		else
			ni_660x_set_pfi_routing(dev, i,
						pfi_output_select_counter);
		ni_660x_select_pfi_output(dev, i, pfi_output_select_high_Z);
	}
	/* to be safe, set counterswap bits on tio chips after all the counter
	   outputs have been set to high impedance mode */
	for (i = 0; i < board(dev)->n_chips; ++i)
		set_tio_counterswap(dev, i);

	ret = request_irq(mite_irq(private(dev)->mite), ni_660x_interrupt,
			  IRQF_SHARED, "ni_660x", dev);
	if (ret < 0) {
		printk(KERN_WARNING " irq not available\n");
		return ret;
	}
	dev->irq = mite_irq(private(dev)->mite);
	global_interrupt_config_bits = Global_Int_Enable_Bit;
	if (board(dev)->n_chips > 1)
		global_interrupt_config_bits |= Cascade_Int_Enable_Bit;
	ni_660x_write_register(dev, 0, global_interrupt_config_bits,
			       GlobalInterruptConfigRegister);
	printk(KERN_INFO "attached\n");
	return 0;
}

static int ni_660x_detach(struct comedi_device *dev)
{
	printk(KERN_INFO "comedi%d: ni_660x: remove\n", dev->minor);

	/* Free irq */
	if (dev->irq)
		free_irq(dev->irq, dev);

	if (dev->private) {
		if (private(dev)->counter_dev)
			ni_gpct_device_destroy(private(dev)->counter_dev);
		if (private(dev)->mite) {
			ni_660x_free_mite_rings(dev);
			mite_unsetup(private(dev)->mite);
		}
	}
	return 0;
}

static int
ni_660x_GPCT_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
		   struct comedi_insn *insn, unsigned int *data)
{
	return ni_tio_rinsn(subdev_to_counter(s), insn, data);
}

static void init_tio_chip(struct comedi_device *dev, int chipset)
{
	unsigned i;

	/*  init dma configuration register */
	private(dev)->dma_configuration_soft_copies[chipset] = 0;
	for (i = 0; i < MAX_DMA_CHANNEL; ++i) {
		private(dev)->dma_configuration_soft_copies[chipset] |=
		    dma_select_bits(i, dma_selection_none) & dma_select_mask(i);
	}
	ni_660x_write_register(dev, chipset,
			       private(dev)->
			       dma_configuration_soft_copies[chipset],
			       DMAConfigRegister);
	for (i = 0; i < NUM_PFI_CHANNELS; ++i)
		ni_660x_write_register(dev, chipset, 0, IOConfigReg(i));
}

static int
ni_660x_GPCT_insn_config(struct comedi_device *dev, struct comedi_subdevice *s,
			 struct comedi_insn *insn, unsigned int *data)
{
	return ni_tio_insn_config(subdev_to_counter(s), insn, data);
}

static int ni_660x_GPCT_winsn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data)
{
	return ni_tio_winsn(subdev_to_counter(s), insn, data);
}

static int ni_660x_find_device(struct comedi_device *dev, int bus, int slot)
{
	struct mite_struct *mite;
	int i;

	for (mite = mite_devices; mite; mite = mite->next) {
		if (mite->used)
			continue;
		if (bus || slot) {
			if (bus != mite->pcidev->bus->number ||
			    slot != PCI_SLOT(mite->pcidev->devfn))
				continue;
		}

		for (i = 0; i < n_ni_660x_boards; i++) {
			if (mite_device_id(mite) == ni_660x_boards[i].dev_id) {
				dev->board_ptr = ni_660x_boards + i;
				private(dev)->mite = mite;
				return 0;
			}
		}
	}
	printk(KERN_WARNING "no device found\n");
	mite_list_devices();
	return -EIO;
}

static int ni_660x_dio_insn_bits(struct comedi_device *dev,
				 struct comedi_subdevice *s,
				 struct comedi_insn *insn, unsigned int *data)
{
	unsigned base_bitfield_channel = CR_CHAN(insn->chanspec);

	/*  Check if we have to write some bits */
	if (data[0]) {
		s->state &= ~(data[0] << base_bitfield_channel);
		s->state |= (data[0] & data[1]) << base_bitfield_channel;
		/* Write out the new digital output lines */
		ni_660x_write_register(dev, 0, s->state, DIO32Output);
	}
	/* on return, data[1] contains the value of the digital
	 * input and output lines. */
	data[1] =
	    (ni_660x_read_register(dev, 0,
				   DIO32Input) >> base_bitfield_channel);
	return 2;
}

static void ni_660x_select_pfi_output(struct comedi_device *dev,
				      unsigned pfi_channel,
				      unsigned output_select)
{
	static const unsigned counter_4_7_first_pfi = 8;
	static const unsigned counter_4_7_last_pfi = 23;
	unsigned active_chipset = 0;
	unsigned idle_chipset = 0;
	unsigned active_bits;
	unsigned idle_bits;

	if (board(dev)->n_chips > 1) {
		if (output_select == pfi_output_select_counter &&
		    pfi_channel >= counter_4_7_first_pfi &&
		    pfi_channel <= counter_4_7_last_pfi) {
			active_chipset = 1;
			idle_chipset = 0;
		} else {
			active_chipset = 0;
			idle_chipset = 1;
		}
	}

	if (idle_chipset != active_chipset) {
		idle_bits =
		    ni_660x_read_register(dev, idle_chipset,
					  IOConfigReg(pfi_channel));
		idle_bits &= ~pfi_output_select_mask(pfi_channel);
		idle_bits |=
		    pfi_output_select_bits(pfi_channel,
					   pfi_output_select_high_Z);
		ni_660x_write_register(dev, idle_chipset, idle_bits,
				       IOConfigReg(pfi_channel));
	}

	active_bits =
	    ni_660x_read_register(dev, active_chipset,
				  IOConfigReg(pfi_channel));
	active_bits &= ~pfi_output_select_mask(pfi_channel);
	active_bits |= pfi_output_select_bits(pfi_channel, output_select);
	ni_660x_write_register(dev, active_chipset, active_bits,
			       IOConfigReg(pfi_channel));
}

static int ni_660x_set_pfi_routing(struct comedi_device *dev, unsigned chan,
				   unsigned source)
{
	if (source > num_pfi_output_selects)
		return -EINVAL;
	if (source == pfi_output_select_high_Z)
		return -EINVAL;
	if (chan < min_counter_pfi_chan) {
		if (source == pfi_output_select_counter)
			return -EINVAL;
	} else if (chan > max_dio_pfi_chan) {
		if (source == pfi_output_select_do)
			return -EINVAL;
	}
	BUG_ON(chan >= NUM_PFI_CHANNELS);

	private(dev)->pfi_output_selects[chan] = source;
	if (private(dev)->pfi_direction_bits & (((uint64_t) 1) << chan))
		ni_660x_select_pfi_output(dev, chan,
					  private(dev)->
					  pfi_output_selects[chan]);
	return 0;
}

static unsigned ni_660x_get_pfi_routing(struct comedi_device *dev,
					unsigned chan)
{
	BUG_ON(chan >= NUM_PFI_CHANNELS);
	return private(dev)->pfi_output_selects[chan];
}

static void ni660x_config_filter(struct comedi_device *dev,
				 unsigned pfi_channel,
				 enum ni_gpct_filter_select filter)
{
	unsigned bits = ni_660x_read_register(dev, 0, IOConfigReg(pfi_channel));
	bits &= ~pfi_input_select_mask(pfi_channel);
	bits |= pfi_input_select_bits(pfi_channel, filter);
	ni_660x_write_register(dev, 0, bits, IOConfigReg(pfi_channel));
}

static int ni_660x_dio_insn_config(struct comedi_device *dev,
				   struct comedi_subdevice *s,
				   struct comedi_insn *insn, unsigned int *data)
{
	int chan = CR_CHAN(insn->chanspec);

	/* The input or output configuration of each digital line is
	 * configured by a special insn_config instruction.  chanspec
	 * contains the channel to be changed, and data[0] contains the
	 * value COMEDI_INPUT or COMEDI_OUTPUT. */

	switch (data[0]) {
	case INSN_CONFIG_DIO_OUTPUT:
		private(dev)->pfi_direction_bits |= ((uint64_t) 1) << chan;
		ni_660x_select_pfi_output(dev, chan,
					  private(dev)->
					  pfi_output_selects[chan]);
		break;
	case INSN_CONFIG_DIO_INPUT:
		private(dev)->pfi_direction_bits &= ~(((uint64_t) 1) << chan);
		ni_660x_select_pfi_output(dev, chan, pfi_output_select_high_Z);
		break;
	case INSN_CONFIG_DIO_QUERY:
		data[1] =
		    (private(dev)->pfi_direction_bits &
		     (((uint64_t) 1) << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT;
		return 0;
	case INSN_CONFIG_SET_ROUTING:
		return ni_660x_set_pfi_routing(dev, chan, data[1]);
		break;
	case INSN_CONFIG_GET_ROUTING:
		data[1] = ni_660x_get_pfi_routing(dev, chan);
		break;
	case INSN_CONFIG_FILTER:
		ni660x_config_filter(dev, chan, data[1]);
		break;
	default:
		return -EINVAL;
		break;
	};
	return 0;
}