xref: /drivers/staging/comedi/drivers/cb_pcidas.c

/*
    comedi/drivers/cb_pcidas.c

    Developed by Ivan Martinez and Frank Mori Hess, with valuable help from
    David Schleef and the rest of the Comedi developers comunity.

    Copyright (C) 2001-2003 Ivan Martinez <imr@oersted.dtu.dk>
    Copyright (C) 2001,2002 Frank Mori Hess <fmhess@users.sourceforge.net>

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>

    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: cb_pcidas
Description: MeasurementComputing PCI-DAS series with the AMCC S5933 PCI controller
Author: Ivan Martinez <imr@oersted.dtu.dk>,
  Frank Mori Hess <fmhess@users.sourceforge.net>
Updated: 2003-3-11
Devices: [Measurement Computing] PCI-DAS1602/16 (cb_pcidas),
  PCI-DAS1602/16jr, PCI-DAS1602/12, PCI-DAS1200, PCI-DAS1200jr,
  PCI-DAS1000, PCI-DAS1001, PCI_DAS1002

Status:
  There are many reports of the driver being used with most of the
  supported cards. Despite no detailed log is maintained, it can
  be said that the driver is quite tested and stable.

  The boards may be autocalibrated using the comedi_calibrate
  utility.

Configuration options:
  [0] - PCI bus of device (optional)
  [1] - PCI slot of device (optional)
  If bus/slot is not specified, the first supported
  PCI device found will be used.

For commands, the scanned channels must be consecutive
(i.e. 4-5-6-7, 2-3-4,...), and must all have the same
range and aref.
*/
/*

TODO:

analog triggering on 1602 series
*/

#include "../comedidev.h"
#include <linux/delay.h>
#include <linux/interrupt.h>

#include "8253.h"
#include "8255.h"
#include "amcc_s5933.h"
#include "comedi_pci.h"
#include "comedi_fc.h"

#undef CB_PCIDAS_DEBUG		/*  disable debugging code */
/* #define CB_PCIDAS_DEBUG         enable debugging code */

/* PCI vendor number of ComputerBoards/MeasurementComputing */
#define PCI_VENDOR_ID_CB	0x1307
#define TIMER_BASE 100		/*  10MHz master clock */
#define AI_BUFFER_SIZE 1024	/*  maximum fifo size of any supported board */
#define AO_BUFFER_SIZE 1024	/*  maximum fifo size of any supported board */
#define NUM_CHANNELS_8800 8
#define NUM_CHANNELS_7376 1
#define NUM_CHANNELS_8402 2
#define NUM_CHANNELS_DAC08 1

/* PCI-DAS base addresses */

/* indices of base address regions */
#define S5933_BADRINDEX 0
#define CONT_STAT_BADRINDEX 1
#define ADC_FIFO_BADRINDEX 2
#define PACER_BADRINDEX 3
#define AO_BADRINDEX 4
/* sizes of io regions */
#define CONT_STAT_SIZE 10
#define ADC_FIFO_SIZE 4
#define PACER_SIZE 12
#define AO_SIZE 4

/* Control/Status registers */
#define INT_ADCFIFO	0	/*  INTERRUPT / ADC FIFO register */
#define   INT_EOS 0x1		/*  interrupt end of scan */
#define   INT_FHF 0x2		/*  interrupt fifo half full */
#define   INT_FNE 0x3		/*  interrupt fifo not empty */
#define   INT_MASK 0x3		/*  mask of interrupt select bits */
#define   INTE 0x4		/*  interrupt enable */
#define   DAHFIE 0x8		/*  dac half full interrupt enable */
#define   EOAIE	0x10		/*  end of aquisition interrupt enable */
#define   DAHFI	0x20		/*  dac half full read status / write interrupt clear */
#define   EOAI 0x40		/*  read end of acq. interrupt status / write clear */
#define   INT 0x80		/*  read interrupt status / write clear */
#define   EOBI 0x200		/*  read end of burst interrupt status */
#define   ADHFI 0x400		/*  read half-full interrupt status */
#define   ADNEI 0x800		/*  read fifo not empty interrupt latch status */
#define   ADNE 0x1000		/*  read, fifo not empty (realtime, not latched) status */
#define   DAEMIE	0x1000	/*  write, dac empty interrupt enable */
#define   LADFUL 0x2000		/*  read fifo overflow / write clear */
#define   DAEMI 0x4000		/*  dac fifo empty interrupt status / write clear */

#define ADCMUX_CONT	2	/*  ADC CHANNEL MUX AND CONTROL register */
#define   BEGIN_SCAN(x)	((x) & 0xf)
#define   END_SCAN(x)	(((x) & 0xf) << 4)
#define   GAIN_BITS(x)	(((x) & 0x3) << 8)
#define   UNIP	0x800		/*  Analog front-end unipolar for range */
#define   SE	0x400		/*  Inputs in single-ended mode */
#define   PACER_MASK	0x3000	/*  pacer source bits */
#define   PACER_INT 0x1000	/*  internal pacer */
#define   PACER_EXT_FALL	0x2000	/*  external falling edge */
#define   PACER_EXT_RISE	0x3000	/*  external rising edge */
#define   EOC	0x4000		/*  adc not busy */

#define TRIG_CONTSTAT 4		/*  TRIGGER CONTROL/STATUS register */
#define   SW_TRIGGER 0x1	/*  software start trigger */
#define   EXT_TRIGGER 0x2	/*  external start trigger */
#define   ANALOG_TRIGGER 0x3	/*  external analog trigger */
#define   TRIGGER_MASK	0x3	/*  mask of bits that determine start trigger */
#define   TGEN	0x10		/*  enable external start trigger */
#define   BURSTE 0x20		/*  burst mode enable */
#define   XTRCL	0x80		/*  clear external trigger */

#define CALIBRATION_REG	6	/*  CALIBRATION register */
#define   SELECT_8800_BIT	0x100	/*  select 8800 caldac */
#define   SELECT_TRIMPOT_BIT	0x200	/*  select ad7376 trim pot */
#define   SELECT_DAC08_BIT	0x400	/*  select dac08 caldac */
#define   CAL_SRC_BITS(x)	(((x) & 0x7) << 11)
#define   CAL_EN_BIT	0x4000	/*  read calibration source instead of analog input channel 0 */
#define   SERIAL_DATA_IN_BIT	0x8000	/*  serial data stream going to 8800 and 7376 */

#define DAC_CSR	0x8		/*  dac control and status register */
enum dac_csr_bits {
	DACEN = 0x2,		/*  dac enable */
	DAC_MODE_UPDATE_BOTH = 0x80,	/*  update both dacs when dac0 is written */
};
static inline unsigned int DAC_RANGE(unsigned int channel, unsigned int range)
{
	return (range & 0x3) << (8 + 2 * (channel & 0x1));
}

static inline unsigned int DAC_RANGE_MASK(unsigned int channel)
{
	return 0x3 << (8 + 2 * (channel & 0x1));
};

/* bits for 1602 series only */
enum dac_csr_bits_1602 {
	DAC_EMPTY = 0x1,	/*  dac fifo empty, read, write clear */
	DAC_START = 0x4,	/*  start/arm dac fifo operations */
	DAC_PACER_MASK = 0x18,	/*  bits that set dac pacer source */
	DAC_PACER_INT = 0x8,	/*  dac internal pacing */
	DAC_PACER_EXT_FALL = 0x10,	/*  dac external pacing, falling edge */
	DAC_PACER_EXT_RISE = 0x18,	/*  dac external pacing, rising edge */
};
static inline unsigned int DAC_CHAN_EN(unsigned int channel)
{
	return 1 << (5 + (channel & 0x1));	/*  enable channel 0 or 1 */
};

/* analog input fifo */
#define ADCDATA	0		/*  ADC DATA register */
#define ADCFIFOCLR	2	/*  ADC FIFO CLEAR */

/* pacer, counter, dio registers */
#define ADC8254 0
#define DIO_8255 4
#define DAC8254 8

/* analog output registers for 100x, 1200 series */
static inline unsigned int DAC_DATA_REG(unsigned int channel)
{
	return 2 * (channel & 0x1);
}

/* analog output registers for 1602 series*/
#define DACDATA	0		/*  DAC DATA register */
#define DACFIFOCLR	2	/*  DAC FIFO CLEAR */

/* bit in hexadecimal representation of range index that indicates unipolar input range */
#define IS_UNIPOLAR 0x4
/* analog input ranges for most boards */
static const struct comedi_lrange cb_pcidas_ranges = {
	8,
	{
	 BIP_RANGE(10),
	 BIP_RANGE(5),
	 BIP_RANGE(2.5),
	 BIP_RANGE(1.25),
	 UNI_RANGE(10),
	 UNI_RANGE(5),
	 UNI_RANGE(2.5),
	 UNI_RANGE(1.25)
	 }
};

/* pci-das1001 input ranges */
static const struct comedi_lrange cb_pcidas_alt_ranges = {
	8,
	{
	 BIP_RANGE(10),
	 BIP_RANGE(1),
	 BIP_RANGE(0.1),
	 BIP_RANGE(0.01),
	 UNI_RANGE(10),
	 UNI_RANGE(1),
	 UNI_RANGE(0.1),
	 UNI_RANGE(0.01)
	 }
};

/* analog output ranges */
static const struct comedi_lrange cb_pcidas_ao_ranges = {
	4,
	{
	 BIP_RANGE(5),
	 BIP_RANGE(10),
	 UNI_RANGE(5),
	 UNI_RANGE(10),
	 }
};

enum trimpot_model {
	AD7376,
	AD8402,
};

struct cb_pcidas_board {
	const char *name;
	unsigned short device_id;
	int ai_se_chans;	/*  Inputs in single-ended mode */
	int ai_diff_chans;	/*  Inputs in differential mode */
	int ai_bits;		/*  analog input resolution */
	int ai_speed;		/*  fastest conversion period in ns */
	int ao_nchan;		/*  number of analog out channels */
	int has_ao_fifo;	/*  analog output has fifo */
	int ao_scan_speed;	/*  analog output speed for 1602 series (for a scan, not conversion) */
	int fifo_size;		/*  number of samples fifo can hold */
	const struct comedi_lrange *ranges;
	enum trimpot_model trimpot;
	unsigned has_dac08:1;
};

static const struct cb_pcidas_board cb_pcidas_boards[] = {
	{
	 .name = "pci-das1602/16",
	 .device_id = 0x1,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 16,
	 .ai_speed = 5000,
	 .ao_nchan = 2,
	 .has_ao_fifo = 1,
	 .ao_scan_speed = 10000,
	 .fifo_size = 512,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD8402,
	 .has_dac08 = 1,
	 },
	{
	 .name = "pci-das1200",
	 .device_id = 0xF,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 3200,
	 .ao_nchan = 2,
	 .has_ao_fifo = 0,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
	{
	 .name = "pci-das1602/12",
	 .device_id = 0x10,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 3200,
	 .ao_nchan = 2,
	 .has_ao_fifo = 1,
	 .ao_scan_speed = 4000,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
	{
	 .name = "pci-das1200/jr",
	 .device_id = 0x19,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 3200,
	 .ao_nchan = 0,
	 .has_ao_fifo = 0,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
	{
	 .name = "pci-das1602/16/jr",
	 .device_id = 0x1C,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 16,
	 .ai_speed = 5000,
	 .ao_nchan = 0,
	 .has_ao_fifo = 0,
	 .fifo_size = 512,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD8402,
	 .has_dac08 = 1,
	 },
	{
	 .name = "pci-das1000",
	 .device_id = 0x4C,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 4000,
	 .ao_nchan = 0,
	 .has_ao_fifo = 0,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
	{
	 .name = "pci-das1001",
	 .device_id = 0x1a,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 6800,
	 .ao_nchan = 2,
	 .has_ao_fifo = 0,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_alt_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
	{
	 .name = "pci-das1002",
	 .device_id = 0x1b,
	 .ai_se_chans = 16,
	 .ai_diff_chans = 8,
	 .ai_bits = 12,
	 .ai_speed = 6800,
	 .ao_nchan = 2,
	 .has_ao_fifo = 0,
	 .fifo_size = 1024,
	 .ranges = &cb_pcidas_ranges,
	 .trimpot = AD7376,
	 .has_dac08 = 0,
	 },
};

static DEFINE_PCI_DEVICE_TABLE(cb_pcidas_pci_table) = {
	{
	PCI_VENDOR_ID_CB, 0x0001, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x000f, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x0010, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x0019, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x001c, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x004c, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x001a, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	PCI_VENDOR_ID_CB, 0x001b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {
	0}
};

MODULE_DEVICE_TABLE(pci, cb_pcidas_pci_table);

/*
 * Useful for shorthand access to the particular board structure
 */
#define thisboard ((const struct cb_pcidas_board *)dev->board_ptr)

/* this structure is for data unique to this hardware driver.  If
   several hardware drivers keep similar information in this structure,
   feel free to suggest moving the variable to the struct comedi_device struct.  */
struct cb_pcidas_private {
	/* would be useful for a PCI device */
	struct pci_dev *pci_dev;
	/*  base addresses */
	unsigned long s5933_config;
	unsigned long control_status;
	unsigned long adc_fifo;
	unsigned long pacer_counter_dio;
	unsigned long ao_registers;
	/*  divisors of master clock for analog input pacing */
	unsigned int divisor1;
	unsigned int divisor2;
	volatile unsigned int count;	/*  number of analog input samples remaining */
	volatile unsigned int adc_fifo_bits;	/*  bits to write to interupt/adcfifo register */
	volatile unsigned int s5933_intcsr_bits;	/*  bits to write to amcc s5933 interrupt control/status register */
	volatile unsigned int ao_control_bits;	/*  bits to write to ao control and status register */
	short ai_buffer[AI_BUFFER_SIZE];
	short ao_buffer[AO_BUFFER_SIZE];
	/*  divisors of master clock for analog output pacing */
	unsigned int ao_divisor1;
	unsigned int ao_divisor2;
	volatile unsigned int ao_count;	/*  number of analog output samples remaining */
	int ao_value[2];	/*  remember what the analog outputs are set to, to allow readback */
	unsigned int caldac_value[NUM_CHANNELS_8800];	/*  for readback of caldac */
	unsigned int trimpot_value[NUM_CHANNELS_8402];	/*  for readback of trimpot */
	unsigned int dac08_value;
	unsigned int calibration_source;
};

/*
 * most drivers define the following macro to make it easy to
 * access the private structure.
 */
#define devpriv ((struct cb_pcidas_private *)dev->private)

/*
 * The struct comedi_driver structure tells the Comedi core module
 * which functions to call to configure/deconfigure (attach/detach)
 * the board, and also about the kernel module that contains
 * the device code.
 */
static int cb_pcidas_attach(struct comedi_device *dev,
			    struct comedi_devconfig *it);
static int cb_pcidas_detach(struct comedi_device *dev);
static struct comedi_driver driver_cb_pcidas = {
	.driver_name = "cb_pcidas",
	.module = THIS_MODULE,
	.attach = cb_pcidas_attach,
	.detach = cb_pcidas_detach,
};

static int cb_pcidas_ai_rinsn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data);
static int ai_config_insn(struct comedi_device *dev, struct comedi_subdevice *s,
			  struct comedi_insn *insn, unsigned int *data);
static int cb_pcidas_ao_nofifo_winsn(struct comedi_device *dev,
				     struct comedi_subdevice *s,
				     struct comedi_insn *insn,
				     unsigned int *data);
static int cb_pcidas_ao_fifo_winsn(struct comedi_device *dev,
				   struct comedi_subdevice *s,
				   struct comedi_insn *insn,
				   unsigned int *data);
static int cb_pcidas_ao_readback_insn(struct comedi_device *dev,
				      struct comedi_subdevice *s,
				      struct comedi_insn *insn,
				      unsigned int *data);
static int cb_pcidas_ai_cmd(struct comedi_device *dev,
			    struct comedi_subdevice *s);
static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_cmd *cmd);
static int cb_pcidas_ao_cmd(struct comedi_device *dev,
			    struct comedi_subdevice *s);
static int cb_pcidas_ao_inttrig(struct comedi_device *dev,
				struct comedi_subdevice *subdev,
				unsigned int trig_num);
static int cb_pcidas_ao_cmdtest(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_cmd *cmd);
static irqreturn_t cb_pcidas_interrupt(int irq, void *d);
static void handle_ao_interrupt(struct comedi_device *dev, unsigned int status);
static int cb_pcidas_cancel(struct comedi_device *dev,
			    struct comedi_subdevice *s);
static int cb_pcidas_ao_cancel(struct comedi_device *dev,
			       struct comedi_subdevice *s);
static void cb_pcidas_load_counters(struct comedi_device *dev, unsigned int *ns,
				    int round_flags);
static int eeprom_read_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data);
static int caldac_read_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data);
static int caldac_write_insn(struct comedi_device *dev,
			     struct comedi_subdevice *s,
			     struct comedi_insn *insn, unsigned int *data);
static int trimpot_read_insn(struct comedi_device *dev,
			     struct comedi_subdevice *s,
			     struct comedi_insn *insn, unsigned int *data);
static int cb_pcidas_trimpot_write(struct comedi_device *dev,
				   unsigned int channel, unsigned int value);
static int trimpot_write_insn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data);
static int dac08_read_insn(struct comedi_device *dev,
			   struct comedi_subdevice *s, struct comedi_insn *insn,
			   unsigned int *data);
static int dac08_write(struct comedi_device *dev, unsigned int value);
static int dac08_write_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data);
static int caldac_8800_write(struct comedi_device *dev, unsigned int address,
			     uint8_t value);
static int trimpot_7376_write(struct comedi_device *dev, uint8_t value);
static int trimpot_8402_write(struct comedi_device *dev, unsigned int channel,
			      uint8_t value);
static int nvram_read(struct comedi_device *dev, unsigned int address,
		      uint8_t *data);

static inline unsigned int cal_enable_bits(struct comedi_device *dev)
{
	return CAL_EN_BIT | CAL_SRC_BITS(devpriv->calibration_source);
}

/*
 * Attach is called by the Comedi core to configure the driver
 * for a particular board.
 */
static int cb_pcidas_attach(struct comedi_device *dev,
			    struct comedi_devconfig *it)
{
	struct comedi_subdevice *s;
	struct pci_dev *pcidev;
	int index;
	int i;

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

/*
 * Allocate the private structure area.
 */
	if (alloc_private(dev, sizeof(struct cb_pcidas_private)) < 0)
		return -ENOMEM;

/*
 * Probe the device to determine what device in the series it is.
 */
	printk("\n");

	for (pcidev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
	     pcidev != NULL;
	     pcidev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pcidev)) {
		/*  is it not a computer boards card? */
		if (pcidev->vendor != PCI_VENDOR_ID_CB)
			continue;
		/*  loop through cards supported by this driver */
		for (index = 0; index < ARRAY_SIZE(cb_pcidas_boards); index++) {
			if (cb_pcidas_boards[index].device_id != pcidev->device)
				continue;
			/*  was a particular bus/slot requested? */
			if (it->options[0] || it->options[1]) {
				/*  are we on the wrong bus/slot? */
				if (pcidev->bus->number != it->options[0] ||
				    PCI_SLOT(pcidev->devfn) != it->options[1]) {
					continue;
				}
			}
			devpriv->pci_dev = pcidev;
			dev->board_ptr = cb_pcidas_boards + index;
			goto found;
		}
	}

	printk("No supported ComputerBoards/MeasurementComputing card found on "
	       "requested position\n");
	return -EIO;

found:

	printk("Found %s on bus %i, slot %i\n", cb_pcidas_boards[index].name,
	       pcidev->bus->number, PCI_SLOT(pcidev->devfn));

	/*
	 * Enable PCI device and reserve I/O ports.
	 */
	if (comedi_pci_enable(pcidev, "cb_pcidas")) {
		printk(" Failed to enable PCI device and request regions\n");
		return -EIO;
	}
	/*
	 * Initialize devpriv->control_status and devpriv->adc_fifo to point to
	 * their base address.
	 */
	devpriv->s5933_config =
	    pci_resource_start(devpriv->pci_dev, S5933_BADRINDEX);
	devpriv->control_status =
	    pci_resource_start(devpriv->pci_dev, CONT_STAT_BADRINDEX);
	devpriv->adc_fifo =
	    pci_resource_start(devpriv->pci_dev, ADC_FIFO_BADRINDEX);
	devpriv->pacer_counter_dio =
	    pci_resource_start(devpriv->pci_dev, PACER_BADRINDEX);
	if (thisboard->ao_nchan) {
		devpriv->ao_registers =
		    pci_resource_start(devpriv->pci_dev, AO_BADRINDEX);
	}
	/*  disable and clear interrupts on amcc s5933 */
	outl(INTCSR_INBOX_INTR_STATUS,
	     devpriv->s5933_config + AMCC_OP_REG_INTCSR);

	/*  get irq */
	if (request_irq(devpriv->pci_dev->irq, cb_pcidas_interrupt,
			IRQF_SHARED, "cb_pcidas", dev)) {
		printk(" unable to allocate irq %d\n", devpriv->pci_dev->irq);
		return -EINVAL;
	}
	dev->irq = devpriv->pci_dev->irq;

	/* Initialize dev->board_name */
	dev->board_name = thisboard->name;

/*
 * Allocate the subdevice structures.
 */
	if (alloc_subdevices(dev, 7) < 0)
		return -ENOMEM;

	s = dev->subdevices + 0;
	/* analog input subdevice */
	dev->read_subdev = s;
	s->type = COMEDI_SUBD_AI;
	s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_DIFF | SDF_CMD_READ;
	/* WARNING: Number of inputs in differential mode is ignored */
	s->n_chan = thisboard->ai_se_chans;
	s->len_chanlist = thisboard->ai_se_chans;
	s->maxdata = (1 << thisboard->ai_bits) - 1;
	s->range_table = thisboard->ranges;
	s->insn_read = cb_pcidas_ai_rinsn;
	s->insn_config = ai_config_insn;
	s->do_cmd = cb_pcidas_ai_cmd;
	s->do_cmdtest = cb_pcidas_ai_cmdtest;
	s->cancel = cb_pcidas_cancel;

	/* analog output subdevice */
	s = dev->subdevices + 1;
	if (thisboard->ao_nchan) {
		s->type = COMEDI_SUBD_AO;
		s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_GROUND;
		s->n_chan = thisboard->ao_nchan;
		/*  analog out resolution is the same as analog input resolution, so use ai_bits */
		s->maxdata = (1 << thisboard->ai_bits) - 1;
		s->range_table = &cb_pcidas_ao_ranges;
		s->insn_read = cb_pcidas_ao_readback_insn;
		if (thisboard->has_ao_fifo) {
			dev->write_subdev = s;
			s->subdev_flags |= SDF_CMD_WRITE;
			s->insn_write = cb_pcidas_ao_fifo_winsn;
			s->do_cmdtest = cb_pcidas_ao_cmdtest;
			s->do_cmd = cb_pcidas_ao_cmd;
			s->cancel = cb_pcidas_ao_cancel;
		} else {
			s->insn_write = cb_pcidas_ao_nofifo_winsn;
		}
	} else {
		s->type = COMEDI_SUBD_UNUSED;
	}

	/* 8255 */
	s = dev->subdevices + 2;
	subdev_8255_init(dev, s, NULL, devpriv->pacer_counter_dio + DIO_8255);

	/*  serial EEPROM, */
	s = dev->subdevices + 3;
	s->type = COMEDI_SUBD_MEMORY;
	s->subdev_flags = SDF_READABLE | SDF_INTERNAL;
	s->n_chan = 256;
	s->maxdata = 0xff;
	s->insn_read = eeprom_read_insn;

	/*  8800 caldac */
	s = dev->subdevices + 4;
	s->type = COMEDI_SUBD_CALIB;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	s->n_chan = NUM_CHANNELS_8800;
	s->maxdata = 0xff;
	s->insn_read = caldac_read_insn;
	s->insn_write = caldac_write_insn;
	for (i = 0; i < s->n_chan; i++)
		caldac_8800_write(dev, i, s->maxdata / 2);

	/*  trim potentiometer */
	s = dev->subdevices + 5;
	s->type = COMEDI_SUBD_CALIB;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	if (thisboard->trimpot == AD7376) {
		s->n_chan = NUM_CHANNELS_7376;
		s->maxdata = 0x7f;
	} else {
		s->n_chan = NUM_CHANNELS_8402;
		s->maxdata = 0xff;
	}
	s->insn_read = trimpot_read_insn;
	s->insn_write = trimpot_write_insn;
	for (i = 0; i < s->n_chan; i++)
		cb_pcidas_trimpot_write(dev, i, s->maxdata / 2);

	/*  dac08 caldac */
	s = dev->subdevices + 6;
	if (thisboard->has_dac08) {
		s->type = COMEDI_SUBD_CALIB;
		s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
		s->n_chan = NUM_CHANNELS_DAC08;
		s->insn_read = dac08_read_insn;
		s->insn_write = dac08_write_insn;
		s->maxdata = 0xff;
		dac08_write(dev, s->maxdata / 2);
	} else
		s->type = COMEDI_SUBD_UNUSED;

	/*  make sure mailbox 4 is empty */
	inl(devpriv->s5933_config + AMCC_OP_REG_IMB4);
	/* Set bits to enable incoming mailbox interrupts on amcc s5933. */
	devpriv->s5933_intcsr_bits =
	    INTCSR_INBOX_BYTE(3) | INTCSR_INBOX_SELECT(3) |
	    INTCSR_INBOX_FULL_INT;
	/*  clear and enable interrupt on amcc s5933 */
	outl(devpriv->s5933_intcsr_bits | INTCSR_INBOX_INTR_STATUS,
	     devpriv->s5933_config + AMCC_OP_REG_INTCSR);

	return 1;
}

/*
 * cb_pcidas_detach is called to deconfigure a device.  It should deallocate
 * resources.
 * This function is also called when _attach() fails, so it should be
 * careful not to release resources that were not necessarily
 * allocated by _attach().  dev->private and dev->subdevices are
 * deallocated automatically by the core.
 */
static int cb_pcidas_detach(struct comedi_device *dev)
{
	printk("comedi%d: cb_pcidas: remove\n", dev->minor);

	if (devpriv) {
		if (devpriv->s5933_config) {
			/*  disable and clear interrupts on amcc s5933 */
			outl(INTCSR_INBOX_INTR_STATUS,
			     devpriv->s5933_config + AMCC_OP_REG_INTCSR);
#ifdef CB_PCIDAS_DEBUG
			printk("detaching, incsr is 0x%x\n",
			       inl(devpriv->s5933_config + AMCC_OP_REG_INTCSR));
#endif
		}
	}
	if (dev->irq)
		free_irq(dev->irq, dev);
	if (dev->subdevices)
		subdev_8255_cleanup(dev, dev->subdevices + 2);
	if (devpriv && devpriv->pci_dev) {
		if (devpriv->s5933_config)
			comedi_pci_disable(devpriv->pci_dev);
		pci_dev_put(devpriv->pci_dev);
	}

	return 0;
}

/*
 * "instructions" read/write data in "one-shot" or "software-triggered"
 * mode.
 */
static int cb_pcidas_ai_rinsn(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_insn *insn, unsigned int *data)
{
	int n, i;
	unsigned int bits;
	static const int timeout = 10000;
	int channel;
	/*  enable calibration input if appropriate */
	if (insn->chanspec & CR_ALT_SOURCE) {
		outw(cal_enable_bits(dev),
		     devpriv->control_status + CALIBRATION_REG);
		channel = 0;
	} else {
		outw(0, devpriv->control_status + CALIBRATION_REG);
		channel = CR_CHAN(insn->chanspec);
	}
	/*  set mux limits and gain */
	bits = BEGIN_SCAN(channel) |
	    END_SCAN(channel) | GAIN_BITS(CR_RANGE(insn->chanspec));
	/*  set unipolar/bipolar */
	if (CR_RANGE(insn->chanspec) & IS_UNIPOLAR)
		bits |= UNIP;
	/*  set singleended/differential */
	if (CR_AREF(insn->chanspec) != AREF_DIFF)
		bits |= SE;
	outw(bits, devpriv->control_status + ADCMUX_CONT);

	/* clear fifo */
	outw(0, devpriv->adc_fifo + ADCFIFOCLR);

	/* convert n samples */
	for (n = 0; n < insn->n; n++) {
		/* trigger conversion */
		outw(0, devpriv->adc_fifo + ADCDATA);

		/* wait for conversion to end */
		/* return -ETIMEDOUT if there is a timeout */
		for (i = 0; i < timeout; i++) {
			if (inw(devpriv->control_status + ADCMUX_CONT) & EOC)
				break;
		}
		if (i == timeout)
			return -ETIMEDOUT;

		/* read data */
		data[n] = inw(devpriv->adc_fifo + ADCDATA);
	}

	/* return the number of samples read/written */
	return n;
}

static int ai_config_calibration_source(struct comedi_device *dev,
					unsigned int *data)
{
	static const int num_calibration_sources = 8;
	unsigned int source = data[1];

	if (source >= num_calibration_sources) {
		printk("invalid calibration source: %i\n", source);
		return -EINVAL;
	}

	devpriv->calibration_source = source;

	return 2;
}

static int ai_config_insn(struct comedi_device *dev, struct comedi_subdevice *s,
			  struct comedi_insn *insn, unsigned int *data)
{
	int id = data[0];

	switch (id) {
	case INSN_CONFIG_ALT_SOURCE:
		return ai_config_calibration_source(dev, data);
		break;
	default:
		return -EINVAL;
		break;
	}
	return -EINVAL;
}

/* analog output insn for pcidas-1000 and 1200 series */
static int cb_pcidas_ao_nofifo_winsn(struct comedi_device *dev,
				     struct comedi_subdevice *s,
				     struct comedi_insn *insn,
				     unsigned int *data)
{
	int channel;
	unsigned long flags;

	/*  set channel and range */
	channel = CR_CHAN(insn->chanspec);
	spin_lock_irqsave(&dev->spinlock, flags);
	devpriv->ao_control_bits &=
	    ~DAC_MODE_UPDATE_BOTH & ~DAC_RANGE_MASK(channel);
	devpriv->ao_control_bits |=
	    DACEN | DAC_RANGE(channel, CR_RANGE(insn->chanspec));
	outw(devpriv->ao_control_bits, devpriv->control_status + DAC_CSR);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	/*  remember value for readback */
	devpriv->ao_value[channel] = data[0];
	/*  send data */
	outw(data[0], devpriv->ao_registers + DAC_DATA_REG(channel));

	return 1;
}

/* analog output insn for pcidas-1602 series */
static int cb_pcidas_ao_fifo_winsn(struct comedi_device *dev,
				   struct comedi_subdevice *s,
				   struct comedi_insn *insn, unsigned int *data)
{
	int channel;
	unsigned long flags;

	/*  clear dac fifo */
	outw(0, devpriv->ao_registers + DACFIFOCLR);

	/*  set channel and range */
	channel = CR_CHAN(insn->chanspec);
	spin_lock_irqsave(&dev->spinlock, flags);
	devpriv->ao_control_bits &=
	    ~DAC_CHAN_EN(0) & ~DAC_CHAN_EN(1) & ~DAC_RANGE_MASK(channel) &
	    ~DAC_PACER_MASK;
	devpriv->ao_control_bits |=
	    DACEN | DAC_RANGE(channel,
			      CR_RANGE(insn->
				       chanspec)) | DAC_CHAN_EN(channel) |
	    DAC_START;
	outw(devpriv->ao_control_bits, devpriv->control_status + DAC_CSR);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	/*  remember value for readback */
	devpriv->ao_value[channel] = data[0];
	/*  send data */
	outw(data[0], devpriv->ao_registers + DACDATA);

	return 1;
}

/* analog output readback insn */
/* XXX loses track of analog output value back after an analog ouput command is executed */
static int cb_pcidas_ao_readback_insn(struct comedi_device *dev,
				      struct comedi_subdevice *s,
				      struct comedi_insn *insn,
				      unsigned int *data)
{
	data[0] = devpriv->ao_value[CR_CHAN(insn->chanspec)];

	return 1;
}

static int eeprom_read_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data)
{
	uint8_t nvram_data;
	int retval;

	retval = nvram_read(dev, CR_CHAN(insn->chanspec), &nvram_data);
	if (retval < 0)
		return retval;

	data[0] = nvram_data;

	return 1;
}

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

	return caldac_8800_write(dev, channel, data[0]);
}

static int caldac_read_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data)
{
	data[0] = devpriv->caldac_value[CR_CHAN(insn->chanspec)];

	return 1;
}

/* 1602/16 pregain offset */
static int dac08_write(struct comedi_device *dev, unsigned int value)
{
	if (devpriv->dac08_value == value)
		return 1;

	devpriv->dac08_value = value;

	outw(cal_enable_bits(dev) | (value & 0xff),
	     devpriv->control_status + CALIBRATION_REG);
	udelay(1);
	outw(cal_enable_bits(dev) | SELECT_DAC08_BIT | (value & 0xff),
	     devpriv->control_status + CALIBRATION_REG);
	udelay(1);
	outw(cal_enable_bits(dev) | (value & 0xff),
	     devpriv->control_status + CALIBRATION_REG);
	udelay(1);

	return 1;
}

static int dac08_write_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data)
{
	return dac08_write(dev, data[0]);
}

static int dac08_read_insn(struct comedi_device *dev,
			   struct comedi_subdevice *s, struct comedi_insn *insn,
			   unsigned int *data)
{
	data[0] = devpriv->dac08_value;

	return 1;
}

static int cb_pcidas_trimpot_write(struct comedi_device *dev,
				   unsigned int channel, unsigned int value)
{
	if (devpriv->trimpot_value[channel] == value)
		return 1;

	devpriv->trimpot_value[channel] = value;
	switch (thisboard->trimpot) {
	case AD7376:
		trimpot_7376_write(dev, value);
		break;
	case AD8402:
		trimpot_8402_write(dev, channel, value);
		break;
	default:
		comedi_error(dev, "driver bug?");
		return -1;
		break;
	}

	return 1;
}

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

	return cb_pcidas_trimpot_write(dev, channel, data[0]);
}

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

	data[0] = devpriv->trimpot_value[channel];

	return 1;
}

static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_cmd *cmd)
{
	int err = 0;
	int tmp;
	int i, gain, start_chan;

	/* cmdtest tests a particular command to see if it is valid.
	 * Using the cmdtest ioctl, a user can create a valid cmd
	 * and then have it executes by the cmd ioctl.
	 *
	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
	 * the command passes. */

	/* step 1: make sure trigger sources are trivially valid */

	tmp = cmd->start_src;
	cmd->start_src &= TRIG_NOW | TRIG_EXT;
	if (!cmd->start_src || tmp != cmd->start_src)
		err++;

	tmp = cmd->scan_begin_src;
	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT;
	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
		err++;

	tmp = cmd->convert_src;
	cmd->convert_src &= TRIG_TIMER | TRIG_NOW | TRIG_EXT;
	if (!cmd->convert_src || tmp != cmd->convert_src)
		err++;

	tmp = cmd->scan_end_src;
	cmd->scan_end_src &= TRIG_COUNT;
	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
		err++;

	tmp = cmd->stop_src;
	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
	if (!cmd->stop_src || tmp != cmd->stop_src)
		err++;

	if (err)
		return 1;

	/* step 2: make sure trigger sources are unique and mutually compatible */

	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
		err++;
	if (cmd->scan_begin_src != TRIG_FOLLOW &&
	    cmd->scan_begin_src != TRIG_TIMER &&
	    cmd->scan_begin_src != TRIG_EXT)
		err++;
	if (cmd->convert_src != TRIG_TIMER &&
	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
		err++;
	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
		err++;

	/*  make sure trigger sources are compatible with each other */
	if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
		err++;
	if (cmd->scan_begin_src != TRIG_FOLLOW && cmd->convert_src != TRIG_NOW)
		err++;
	if (cmd->start_src == TRIG_EXT &&
	    (cmd->convert_src == TRIG_EXT || cmd->scan_begin_src == TRIG_EXT))
		err++;

	if (err)
		return 2;

	/* step 3: make sure arguments are trivially compatible */

	if (cmd->start_arg != 0) {
		cmd->start_arg = 0;
		err++;
	}

	if (cmd->scan_begin_src == TRIG_TIMER) {
		if (cmd->scan_begin_arg <
		    thisboard->ai_speed * cmd->chanlist_len) {
			cmd->scan_begin_arg =
			    thisboard->ai_speed * cmd->chanlist_len;
			err++;
		}
	}
	if (cmd->convert_src == TRIG_TIMER) {
		if (cmd->convert_arg < thisboard->ai_speed) {
			cmd->convert_arg = thisboard->ai_speed;
			err++;
		}
	}

	if (cmd->scan_end_arg != cmd->chanlist_len) {
		cmd->scan_end_arg = cmd->chanlist_len;
		err++;
	}
	if (cmd->stop_src == TRIG_NONE) {
		/* TRIG_NONE */
		if (cmd->stop_arg != 0) {
			cmd->stop_arg = 0;
			err++;
		}
	}

	if (err)
		return 3;

	/* step 4: fix up any arguments */

	if (cmd->scan_begin_src == TRIG_TIMER) {
		tmp = cmd->scan_begin_arg;
		i8253_cascade_ns_to_timer_2div(TIMER_BASE,
					       &(devpriv->divisor1),
					       &(devpriv->divisor2),
					       &(cmd->scan_begin_arg),
					       cmd->flags & TRIG_ROUND_MASK);
		if (tmp != cmd->scan_begin_arg)
			err++;
	}
	if (cmd->convert_src == TRIG_TIMER) {
		tmp = cmd->convert_arg;
		i8253_cascade_ns_to_timer_2div(TIMER_BASE,
					       &(devpriv->divisor1),
					       &(devpriv->divisor2),
					       &(cmd->convert_arg),
					       cmd->flags & TRIG_ROUND_MASK);
		if (tmp != cmd->convert_arg)
			err++;
	}

	if (err)
		return 4;

	/*  check channel/gain list against card's limitations */
	if (cmd->chanlist) {
		gain = CR_RANGE(cmd->chanlist[0]);
		start_chan = CR_CHAN(cmd->chanlist[0]);
		for (i = 1; i < cmd->chanlist_len; i++) {
			if (CR_CHAN(cmd->chanlist[i]) !=
			    (start_chan + i) % s->n_chan) {
				comedi_error(dev,
					     "entries in chanlist must be consecutive channels, counting upwards\n");
				err++;
			}
			if (CR_RANGE(cmd->chanlist[i]) != gain) {
				comedi_error(dev,
					     "entries in chanlist must all have the same gain\n");
				err++;
			}
		}
	}

	if (err)
		return 5;

	return 0;
}

static int cb_pcidas_ai_cmd(struct comedi_device *dev,
			    struct comedi_subdevice *s)
{
	struct comedi_async *async = s->async;
	struct comedi_cmd *cmd = &async->cmd;
	unsigned int bits;
	unsigned long flags;

	/*  make sure CAL_EN_BIT is disabled */
	outw(0, devpriv->control_status + CALIBRATION_REG);
	/*  initialize before settings pacer source and count values */
	outw(0, devpriv->control_status + TRIG_CONTSTAT);
	/*  clear fifo */
	outw(0, devpriv->adc_fifo + ADCFIFOCLR);

	/*  set mux limits, gain and pacer source */
	bits = BEGIN_SCAN(CR_CHAN(cmd->chanlist[0])) |
	    END_SCAN(CR_CHAN(cmd->chanlist[cmd->chanlist_len - 1])) |
	    GAIN_BITS(CR_RANGE(cmd->chanlist[0]));
	/*  set unipolar/bipolar */
	if (CR_RANGE(cmd->chanlist[0]) & IS_UNIPOLAR)
		bits |= UNIP;
	/*  set singleended/differential */
	if (CR_AREF(cmd->chanlist[0]) != AREF_DIFF)
		bits |= SE;
	/*  set pacer source */
	if (cmd->convert_src == TRIG_EXT || cmd->scan_begin_src == TRIG_EXT)
		bits |= PACER_EXT_RISE;
	else
		bits |= PACER_INT;
	outw(bits, devpriv->control_status + ADCMUX_CONT);

#ifdef CB_PCIDAS_DEBUG
	printk("comedi: sent 0x%x to adcmux control\n", bits);
#endif

	/*  load counters */
	if (cmd->convert_src == TRIG_TIMER)
		cb_pcidas_load_counters(dev, &cmd->convert_arg,
					cmd->flags & TRIG_ROUND_MASK);
	else if (cmd->scan_begin_src == TRIG_TIMER)
		cb_pcidas_load_counters(dev, &cmd->scan_begin_arg,
					cmd->flags & TRIG_ROUND_MASK);

	/*  set number of conversions */
	if (cmd->stop_src == TRIG_COUNT)
		devpriv->count = cmd->chanlist_len * cmd->stop_arg;
	/*  enable interrupts */
	spin_lock_irqsave(&dev->spinlock, flags);
	devpriv->adc_fifo_bits |= INTE;
	devpriv->adc_fifo_bits &= ~INT_MASK;
	if (cmd->flags & TRIG_WAKE_EOS) {
		if (cmd->convert_src == TRIG_NOW && cmd->chanlist_len > 1)
			devpriv->adc_fifo_bits |= INT_EOS;	/*  interrupt end of burst */
		else
			devpriv->adc_fifo_bits |= INT_FNE;	/*  interrupt fifo not empty */
	} else {
		devpriv->adc_fifo_bits |= INT_FHF;	/* interrupt fifo half full */
	}
#ifdef CB_PCIDAS_DEBUG
	printk("comedi: adc_fifo_bits are 0x%x\n", devpriv->adc_fifo_bits);
#endif
	/*  enable (and clear) interrupts */
	outw(devpriv->adc_fifo_bits | EOAI | INT | LADFUL,
	     devpriv->control_status + INT_ADCFIFO);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	/*  set start trigger and burst mode */
	bits = 0;
	if (cmd->start_src == TRIG_NOW)
		bits |= SW_TRIGGER;
	else if (cmd->start_src == TRIG_EXT)
		bits |= EXT_TRIGGER | TGEN | XTRCL;
	else {
		comedi_error(dev, "bug!");
		return -1;
	}
	if (cmd->convert_src == TRIG_NOW && cmd->chanlist_len > 1)
		bits |= BURSTE;
	outw(bits, devpriv->control_status + TRIG_CONTSTAT);
#ifdef CB_PCIDAS_DEBUG
	printk("comedi: sent 0x%x to trig control\n", bits);
#endif

	return 0;
}

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

	/* cmdtest tests a particular command to see if it is valid.
	 * Using the cmdtest ioctl, a user can create a valid cmd
	 * and then have it executes by the cmd ioctl.
	 *
	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
	 * the command passes. */

	/* step 1: make sure trigger sources are trivially valid */

	tmp = cmd->start_src;
	cmd->start_src &= TRIG_INT;
	if (!cmd->start_src || tmp != cmd->start_src)
		err++;

	tmp = cmd->scan_begin_src;
	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
		err++;

	tmp = cmd->convert_src;
	cmd->convert_src &= TRIG_NOW;
	if (!cmd->convert_src || tmp != cmd->convert_src)
		err++;

	tmp = cmd->scan_end_src;
	cmd->scan_end_src &= TRIG_COUNT;
	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
		err++;

	tmp = cmd->stop_src;
	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
	if (!cmd->stop_src || tmp != cmd->stop_src)
		err++;

	if (err)
		return 1;

	/* step 2: make sure trigger sources are unique and mutually compatible */

	if (cmd->scan_begin_src != TRIG_TIMER &&
	    cmd->scan_begin_src != TRIG_EXT)
		err++;
	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
		err++;

	if (err)
		return 2;

	/* step 3: make sure arguments are trivially compatible */

	if (cmd->start_arg != 0) {
		cmd->start_arg = 0;
		err++;
	}

	if (cmd->scan_begin_src == TRIG_TIMER) {
		if (cmd->scan_begin_arg < thisboard->ao_scan_speed) {
			cmd->scan_begin_arg = thisboard->ao_scan_speed;
			err++;
		}
	}

	if (cmd->scan_end_arg != cmd->chanlist_len) {
		cmd->scan_end_arg = cmd->chanlist_len;
		err++;
	}
	if (cmd->stop_src == TRIG_NONE) {
		/* TRIG_NONE */
		if (cmd->stop_arg != 0) {
			cmd->stop_arg = 0;
			err++;
		}
	}

	if (err)
		return 3;

	/* step 4: fix up any arguments */

	if (cmd->scan_begin_src == TRIG_TIMER) {
		tmp = cmd->scan_begin_arg;
		i8253_cascade_ns_to_timer_2div(TIMER_BASE,
					       &(devpriv->ao_divisor1),
					       &(devpriv->ao_divisor2),
					       &(cmd->scan_begin_arg),
					       cmd->flags & TRIG_ROUND_MASK);
		if (tmp != cmd->scan_begin_arg)
			err++;
	}

	if (err)
		return 4;

	/*  check channel/gain list against card's limitations */
	if (cmd->chanlist && cmd->chanlist_len > 1) {
		if (CR_CHAN(cmd->chanlist[0]) != 0 ||
		    CR_CHAN(cmd->chanlist[1]) != 1) {
			comedi_error(dev,
				     "channels must be ordered channel 0, channel 1 in chanlist\n");
			err++;
		}
	}

	if (err)
		return 5;

	return 0;
}

static int cb_pcidas_ao_cmd(struct comedi_device *dev,
			    struct comedi_subdevice *s)
{
	struct comedi_async *async = s->async;
	struct comedi_cmd *cmd = &async->cmd;
	unsigned int i;
	unsigned long flags;

	/*  set channel limits, gain */
	spin_lock_irqsave(&dev->spinlock, flags);
	for (i = 0; i < cmd->chanlist_len; i++) {
		/*  enable channel */
		devpriv->ao_control_bits |=
		    DAC_CHAN_EN(CR_CHAN(cmd->chanlist[i]));
		/*  set range */
		devpriv->ao_control_bits |= DAC_RANGE(CR_CHAN(cmd->chanlist[i]),
						      CR_RANGE(cmd->
							       chanlist[i]));
	}

	/*  disable analog out before settings pacer source and count values */
	outw(devpriv->ao_control_bits, devpriv->control_status + DAC_CSR);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	/*  clear fifo */
	outw(0, devpriv->ao_registers + DACFIFOCLR);

	/*  load counters */
	if (cmd->scan_begin_src == TRIG_TIMER) {
		i8253_cascade_ns_to_timer_2div(TIMER_BASE,
					       &(devpriv->ao_divisor1),
					       &(devpriv->ao_divisor2),
					       &(cmd->scan_begin_arg),
					       cmd->flags);

		/* Write the values of ctr1 and ctr2 into counters 1 and 2 */
		i8254_load(devpriv->pacer_counter_dio + DAC8254, 0, 1,
			   devpriv->ao_divisor1, 2);
		i8254_load(devpriv->pacer_counter_dio + DAC8254, 0, 2,
			   devpriv->ao_divisor2, 2);
	}
	/*  set number of conversions */
	if (cmd->stop_src == TRIG_COUNT)
		devpriv->ao_count = cmd->chanlist_len * cmd->stop_arg;
	/*  set pacer source */
	spin_lock_irqsave(&dev->spinlock, flags);
	switch (cmd->scan_begin_src) {
	case TRIG_TIMER:
		devpriv->ao_control_bits |= DAC_PACER_INT;
		break;
	case TRIG_EXT:
		devpriv->ao_control_bits |= DAC_PACER_EXT_RISE;
		break;
	default:
		spin_unlock_irqrestore(&dev->spinlock, flags);
		comedi_error(dev, "error setting dac pacer source");
		return -1;
		break;
	}
	spin_unlock_irqrestore(&dev->spinlock, flags);

	async->inttrig = cb_pcidas_ao_inttrig;

	return 0;
}

static int cb_pcidas_ao_inttrig(struct comedi_device *dev,
				struct comedi_subdevice *s,
				unsigned int trig_num)
{
	unsigned int num_bytes, num_points = thisboard->fifo_size;
	struct comedi_async *async = s->async;
	struct comedi_cmd *cmd = &s->async->cmd;
	unsigned long flags;

	if (trig_num != 0)
		return -EINVAL;

	/*  load up fifo */
	if (cmd->stop_src == TRIG_COUNT && devpriv->ao_count < num_points)
		num_points = devpriv->ao_count;

	num_bytes = cfc_read_array_from_buffer(s, devpriv->ao_buffer,
					       num_points * sizeof(short));
	num_points = num_bytes / sizeof(short);

	if (cmd->stop_src == TRIG_COUNT)
		devpriv->ao_count -= num_points;
	/*  write data to board's fifo */
	outsw(devpriv->ao_registers + DACDATA, devpriv->ao_buffer, num_bytes);

	/*  enable dac half-full and empty interrupts */
	spin_lock_irqsave(&dev->spinlock, flags);
	devpriv->adc_fifo_bits |= DAEMIE | DAHFIE;
#ifdef CB_PCIDAS_DEBUG
	printk("comedi: adc_fifo_bits are 0x%x\n", devpriv->adc_fifo_bits);
#endif
	/*  enable and clear interrupts */
	outw(devpriv->adc_fifo_bits | DAEMI | DAHFI,
	     devpriv->control_status + INT_ADCFIFO);

	/*  start dac */
	devpriv->ao_control_bits |= DAC_START | DACEN | DAC_EMPTY;
	outw(devpriv->ao_control_bits, devpriv->control_status + DAC_CSR);
#ifdef CB_PCIDAS_DEBUG
	printk("comedi: sent 0x%x to dac control\n", devpriv->ao_control_bits);
#endif
	spin_unlock_irqrestore(&dev->spinlock, flags);

	async->inttrig = NULL;

	return 0;
}

static irqreturn_t cb_pcidas_interrupt(int irq, void *d)
{
	struct comedi_device *dev = (struct comedi_device *)d;
	struct comedi_subdevice *s = dev->read_subdev;
	struct comedi_async *async;
	int status, s5933_status;
	int half_fifo = thisboard->fifo_size / 2;
	unsigned int num_samples, i;
	static const int timeout = 10000;
	unsigned long flags;

	if (dev->attached == 0)
		return IRQ_NONE;

	async = s->async;
	async->events = 0;

	s5933_status = inl(devpriv->s5933_config + AMCC_OP_REG_INTCSR);
#ifdef CB_PCIDAS_DEBUG
	printk("intcsr 0x%x\n", s5933_status);
	printk("mbef 0x%x\n", inl(devpriv->s5933_config + AMCC_OP_REG_MBEF));
#endif

	if ((INTCSR_INTR_ASSERTED & s5933_status) == 0)
		return IRQ_NONE;

	/*  make sure mailbox 4 is empty */
	inl_p(devpriv->s5933_config + AMCC_OP_REG_IMB4);
	/*  clear interrupt on amcc s5933 */
	outl(devpriv->s5933_intcsr_bits | INTCSR_INBOX_INTR_STATUS,
	     devpriv->s5933_config + AMCC_OP_REG_INTCSR);

	status = inw(devpriv->control_status + INT_ADCFIFO);
#ifdef CB_PCIDAS_DEBUG
	if ((status & (INT | EOAI | LADFUL | DAHFI | DAEMI)) == 0)
		comedi_error(dev, "spurious interrupt");
#endif

	/*  check for analog output interrupt */
	if (status & (DAHFI | DAEMI))
		handle_ao_interrupt(dev, status);
	/*  check for analog input interrupts */
	/*  if fifo half-full */
	if (status & ADHFI) {
		/*  read data */
		num_samples = half_fifo;
		if (async->cmd.stop_src == TRIG_COUNT &&
		    num_samples > devpriv->count) {
			num_samples = devpriv->count;
		}
		insw(devpriv->adc_fifo + ADCDATA, devpriv->ai_buffer,
		     num_samples);
		cfc_write_array_to_buffer(s, devpriv->ai_buffer,
					  num_samples * sizeof(short));
		devpriv->count -= num_samples;
		if (async->cmd.stop_src == TRIG_COUNT && devpriv->count == 0) {
			async->events |= COMEDI_CB_EOA;
			cb_pcidas_cancel(dev, s);
		}
		/*  clear half-full interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | INT,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
		/*  else if fifo not empty */
	} else if (status & (ADNEI | EOBI)) {
		for (i = 0; i < timeout; i++) {
			/*  break if fifo is empty */
			if ((ADNE & inw(devpriv->control_status +
					INT_ADCFIFO)) == 0)
				break;
			cfc_write_to_buffer(s, inw(devpriv->adc_fifo));
			if (async->cmd.stop_src == TRIG_COUNT && --devpriv->count == 0) {	/* end of acquisition */
				cb_pcidas_cancel(dev, s);
				async->events |= COMEDI_CB_EOA;
				break;
			}
		}
		/*  clear not-empty interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | INT,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
	} else if (status & EOAI) {
		comedi_error(dev,
			     "bug! encountered end of aquisition interrupt?");
		/*  clear EOA interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | EOAI,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
	}
	/* check for fifo overflow */
	if (status & LADFUL) {
		comedi_error(dev, "fifo overflow");
		/*  clear overflow interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | LADFUL,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
		cb_pcidas_cancel(dev, s);
		async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
	}

	comedi_event(dev, s);

	return IRQ_HANDLED;
}

static void handle_ao_interrupt(struct comedi_device *dev, unsigned int status)
{
	struct comedi_subdevice *s = dev->write_subdev;
	struct comedi_async *async = s->async;
	struct comedi_cmd *cmd = &async->cmd;
	unsigned int half_fifo = thisboard->fifo_size / 2;
	unsigned int num_points;
	unsigned long flags;

	async->events = 0;

	if (status & DAEMI) {
		/*  clear dac empty interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | DAEMI,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
		if (inw(devpriv->ao_registers + DAC_CSR) & DAC_EMPTY) {
			if (cmd->stop_src == TRIG_NONE ||
			    (cmd->stop_src == TRIG_COUNT
			     && devpriv->ao_count)) {
				comedi_error(dev, "dac fifo underflow");
				cb_pcidas_ao_cancel(dev, s);
				async->events |= COMEDI_CB_ERROR;
			}
			async->events |= COMEDI_CB_EOA;
		}
	} else if (status & DAHFI) {
		unsigned int num_bytes;

		/*  figure out how many points we are writing to fifo */
		num_points = half_fifo;
		if (cmd->stop_src == TRIG_COUNT &&
		    devpriv->ao_count < num_points)
			num_points = devpriv->ao_count;
		num_bytes =
		    cfc_read_array_from_buffer(s, devpriv->ao_buffer,
					       num_points * sizeof(short));
		num_points = num_bytes / sizeof(short);

		if (async->cmd.stop_src == TRIG_COUNT)
			devpriv->ao_count -= num_points;
		/*  write data to board's fifo */
		outsw(devpriv->ao_registers + DACDATA, devpriv->ao_buffer,
		      num_points);
		/*  clear half-full interrupt latch */
		spin_lock_irqsave(&dev->spinlock, flags);
		outw(devpriv->adc_fifo_bits | DAHFI,
		     devpriv->control_status + INT_ADCFIFO);
		spin_unlock_irqrestore(&dev->spinlock, flags);
	}

	comedi_event(dev, s);
}

/* cancel analog input command */
static int cb_pcidas_cancel(struct comedi_device *dev,
			    struct comedi_subdevice *s)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->spinlock, flags);
	/*  disable interrupts */
	devpriv->adc_fifo_bits &= ~INTE & ~EOAIE;
	outw(devpriv->adc_fifo_bits, devpriv->control_status + INT_ADCFIFO);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	/*  disable start trigger source and burst mode */
	outw(0, devpriv->control_status + TRIG_CONTSTAT);
	/*  software pacer source */
	outw(0, devpriv->control_status + ADCMUX_CONT);

	return 0;
}

/* cancel analog output command */
static int cb_pcidas_ao_cancel(struct comedi_device *dev,
			       struct comedi_subdevice *s)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->spinlock, flags);
	/*  disable interrupts */
	devpriv->adc_fifo_bits &= ~DAHFIE & ~DAEMIE;
	outw(devpriv->adc_fifo_bits, devpriv->control_status + INT_ADCFIFO);

	/*  disable output */
	devpriv->ao_control_bits &= ~DACEN & ~DAC_PACER_MASK;
	outw(devpriv->ao_control_bits, devpriv->control_status + DAC_CSR);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	return 0;
}

static void cb_pcidas_load_counters(struct comedi_device *dev, unsigned int *ns,
				    int rounding_flags)
{
	i8253_cascade_ns_to_timer_2div(TIMER_BASE, &(devpriv->divisor1),
				       &(devpriv->divisor2), ns,
				       rounding_flags & TRIG_ROUND_MASK);

	/* Write the values of ctr1 and ctr2 into counters 1 and 2 */
	i8254_load(devpriv->pacer_counter_dio + ADC8254, 0, 1,
		   devpriv->divisor1, 2);
	i8254_load(devpriv->pacer_counter_dio + ADC8254, 0, 2,
		   devpriv->divisor2, 2);
}

static void write_calibration_bitstream(struct comedi_device *dev,
					unsigned int register_bits,
					unsigned int bitstream,
					unsigned int bitstream_length)
{
	static const int write_delay = 1;
	unsigned int bit;

	for (bit = 1 << (bitstream_length - 1); bit; bit >>= 1) {
		if (bitstream & bit)
			register_bits |= SERIAL_DATA_IN_BIT;
		else
			register_bits &= ~SERIAL_DATA_IN_BIT;
		udelay(write_delay);
		outw(register_bits, devpriv->control_status + CALIBRATION_REG);
	}
}

static int caldac_8800_write(struct comedi_device *dev, unsigned int address,
			     uint8_t value)
{
	static const int num_caldac_channels = 8;
	static const int bitstream_length = 11;
	unsigned int bitstream = ((address & 0x7) << 8) | value;
	static const int caldac_8800_udelay = 1;

	if (address >= num_caldac_channels) {
		comedi_error(dev, "illegal caldac channel");
		return -1;
	}

	if (value == devpriv->caldac_value[address])
		return 1;

	devpriv->caldac_value[address] = value;

	write_calibration_bitstream(dev, cal_enable_bits(dev), bitstream,
				    bitstream_length);

	udelay(caldac_8800_udelay);
	outw(cal_enable_bits(dev) | SELECT_8800_BIT,
	     devpriv->control_status + CALIBRATION_REG);
	udelay(caldac_8800_udelay);
	outw(cal_enable_bits(dev), devpriv->control_status + CALIBRATION_REG);

	return 1;
}

static int trimpot_7376_write(struct comedi_device *dev, uint8_t value)
{
	static const int bitstream_length = 7;
	unsigned int bitstream = value & 0x7f;
	unsigned int register_bits;
	static const int ad7376_udelay = 1;

	register_bits = cal_enable_bits(dev) | SELECT_TRIMPOT_BIT;
	udelay(ad7376_udelay);
	outw(register_bits, devpriv->control_status + CALIBRATION_REG);

	write_calibration_bitstream(dev, register_bits, bitstream,
				    bitstream_length);

	udelay(ad7376_udelay);
	outw(cal_enable_bits(dev), devpriv->control_status + CALIBRATION_REG);

	return 0;
}

/* For 1602/16 only
 * ch 0 : adc gain
 * ch 1 : adc postgain offset */
static int trimpot_8402_write(struct comedi_device *dev, unsigned int channel,
			      uint8_t value)
{
	static const int bitstream_length = 10;
	unsigned int bitstream = ((channel & 0x3) << 8) | (value & 0xff);
	unsigned int register_bits;
	static const int ad8402_udelay = 1;

	register_bits = cal_enable_bits(dev) | SELECT_TRIMPOT_BIT;
	udelay(ad8402_udelay);
	outw(register_bits, devpriv->control_status + CALIBRATION_REG);

	write_calibration_bitstream(dev, register_bits, bitstream,
				    bitstream_length);

	udelay(ad8402_udelay);
	outw(cal_enable_bits(dev), devpriv->control_status + CALIBRATION_REG);

	return 0;
}

static int wait_for_nvram_ready(unsigned long s5933_base_addr)
{
	static const int timeout = 1000;
	unsigned int i;

	for (i = 0; i < timeout; i++) {
		if ((inb(s5933_base_addr +
			 AMCC_OP_REG_MCSR_NVCMD) & MCSR_NV_BUSY)
		    == 0)
			return 0;
		udelay(1);
	}
	return -1;
}

static int nvram_read(struct comedi_device *dev, unsigned int address,
			uint8_t *data)
{
	unsigned long iobase = devpriv->s5933_config;

	if (wait_for_nvram_ready(iobase) < 0)
		return -ETIMEDOUT;

	outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_LOW_ADDR,
	     iobase + AMCC_OP_REG_MCSR_NVCMD);
	outb(address & 0xff, iobase + AMCC_OP_REG_MCSR_NVDATA);
	outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_HIGH_ADDR,
	     iobase + AMCC_OP_REG_MCSR_NVCMD);
	outb((address >> 8) & 0xff, iobase + AMCC_OP_REG_MCSR_NVDATA);
	outb(MCSR_NV_ENABLE | MCSR_NV_READ, iobase + AMCC_OP_REG_MCSR_NVCMD);

	if (wait_for_nvram_ready(iobase) < 0)
		return -ETIMEDOUT;

	*data = inb(iobase + AMCC_OP_REG_MCSR_NVDATA);

	return 0;
}

/*
 * A convenient macro that defines init_module() and cleanup_module(),
 * as necessary.
 */
static int __devinit driver_cb_pcidas_pci_probe(struct pci_dev *dev,
						const struct pci_device_id *ent)
{
	return comedi_pci_auto_config(dev, driver_cb_pcidas.driver_name);
}

static void __devexit driver_cb_pcidas_pci_remove(struct pci_dev *dev)
{
	comedi_pci_auto_unconfig(dev);
}

static struct pci_driver driver_cb_pcidas_pci_driver = {
	.id_table = cb_pcidas_pci_table,
	.probe = &driver_cb_pcidas_pci_probe,
	.remove = __devexit_p(&driver_cb_pcidas_pci_remove)
};

static int __init driver_cb_pcidas_init_module(void)
{
	int retval;

	retval = comedi_driver_register(&driver_cb_pcidas);
	if (retval < 0)
		return retval;

	driver_cb_pcidas_pci_driver.name = (char *)driver_cb_pcidas.driver_name;
	return pci_register_driver(&driver_cb_pcidas_pci_driver);
}

static void __exit driver_cb_pcidas_cleanup_module(void)
{
	pci_unregister_driver(&driver_cb_pcidas_pci_driver);
	comedi_driver_unregister(&driver_cb_pcidas);
}

module_init(driver_cb_pcidas_init_module);
module_exit(driver_cb_pcidas_cleanup_module);

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