]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/staging/comedi/drivers/cb_pcidda.c
Merge branch 'omap-pool'
[linux-2.6-omap-h63xx.git] / drivers / staging / comedi / drivers / cb_pcidda.c
diff --git a/drivers/staging/comedi/drivers/cb_pcidda.c b/drivers/staging/comedi/drivers/cb_pcidda.c
new file mode 100644 (file)
index 0000000..ed0a5eb
--- /dev/null
@@ -0,0 +1,841 @@
+/*
+    comedi/drivers/cb_pcidda.c
+    This intends to be a driver for the ComputerBoards / MeasurementComputing
+    PCI-DDA series.
+
+        Copyright (C) 2001 Ivan Martinez <ivanmr@altavista.com>
+    Copyright (C) 2001 Frank Mori Hess <fmhess@users.sourceforge.net>
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
+
+    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_pcidda
+Description: MeasurementComputing PCI-DDA series
+Author: Ivan Martinez <ivanmr@altavista.com>, Frank Mori Hess <fmhess@users.sourceforge.net>
+Status: Supports 08/16, 04/16, 02/16, 08/12, 04/12, and 02/12
+Devices: [Measurement Computing] PCI-DDA08/12 (cb_pcidda), PCI-DDA04/12,
+  PCI-DDA02/12, PCI-DDA08/16, PCI-DDA04/16, PCI-DDA02/16
+
+Configuration options:
+  [0] - PCI bus of device (optional)
+  [1] - PCI slot of device (optional)
+  If bus/slot is not specified, the first available PCI
+  device will be used.
+
+Only simple analog output writing is supported.
+
+So far it has only been tested with:
+  - PCI-DDA08/12
+Please report success/failure with other different cards to
+<comedi@comedi.org>.
+*/
+
+#include "../comedidev.h"
+
+#include "comedi_pci.h"
+#include "8255.h"
+
+#define PCI_VENDOR_ID_CB       0x1307  // PCI vendor number of ComputerBoards
+#define N_BOARDS       10      // Number of boards in cb_pcidda_boards
+#define EEPROM_SIZE    128     // number of entries in eeprom
+#define MAX_AO_CHANNELS 8      // maximum number of ao channels for supported boards
+
+/* PCI-DDA base addresses */
+#define DIGITALIO_BADRINDEX    2
+       // DIGITAL I/O is pci_dev->resource[2]
+#define DIGITALIO_SIZE 8
+       // DIGITAL I/O uses 8 I/O port addresses
+#define DAC_BADRINDEX  3
+       // DAC is pci_dev->resource[3]
+
+/* Digital I/O registers */
+#define PORT1A 0               // PORT 1A DATA
+
+#define PORT1B 1               // PORT 1B DATA
+
+#define PORT1C 2               // PORT 1C DATA
+
+#define CONTROL1 3             // CONTROL REGISTER 1
+
+#define PORT2A 4               // PORT 2A DATA
+
+#define PORT2B 5               // PORT 2B DATA
+
+#define PORT2C 6               // PORT 2C DATA
+
+#define CONTROL2 7             // CONTROL REGISTER 2
+
+/* DAC registers */
+#define DACONTROL      0       // D/A CONTROL REGISTER
+#define        SU      0000001         // Simultaneous update enabled
+#define NOSU   0000000         // Simultaneous update disabled
+#define        ENABLEDAC       0000002 // Enable specified DAC
+#define        DISABLEDAC      0000000 // Disable specified DAC
+#define RANGE2V5       0000000 // 2.5V
+#define RANGE5V        0000200         // 5V
+#define RANGE10V       0000300 // 10V
+#define UNIP   0000400         // Unipolar outputs
+#define BIP    0000000         // Bipolar outputs
+
+#define DACALIBRATION1 4       // D/A CALIBRATION REGISTER 1
+//write bits
+#define        SERIAL_IN_BIT   0x1     // serial data input for eeprom, caldacs, reference dac
+#define        CAL_CHANNEL_MASK        (0x7 << 1)
+#define        CAL_CHANNEL_BITS(channel)       (((channel) << 1) & CAL_CHANNEL_MASK)
+//read bits
+#define        CAL_COUNTER_MASK        0x1f
+#define        CAL_COUNTER_OVERFLOW_BIT        0x20    // calibration counter overflow status bit
+#define        AO_BELOW_REF_BIT        0x40    // analog output is less than reference dac voltage
+#define        SERIAL_OUT_BIT  0x80    // serial data out, for reading from eeprom
+
+#define DACALIBRATION2 6       // D/A CALIBRATION REGISTER 2
+#define        SELECT_EEPROM_BIT       0x1     // send serial data in to eeprom
+#define        DESELECT_REF_DAC_BIT    0x2     // don't send serial data to MAX542 reference dac
+#define        DESELECT_CALDAC_BIT(n)  (0x4 << (n))    // don't send serial data to caldac n
+#define        DUMMY_BIT       0x40    // manual says to set this bit with no explanation
+
+#define DADATA 8               // FIRST D/A DATA REGISTER (0)
+
+static const struct comedi_lrange cb_pcidda_ranges = {
+       6,
+       {
+                       BIP_RANGE(10),
+                       BIP_RANGE(5),
+                       BIP_RANGE(2.5),
+                       UNI_RANGE(10),
+                       UNI_RANGE(5),
+                       UNI_RANGE(2.5),
+               }
+};
+
+/*
+ * Board descriptions for two imaginary boards.  Describing the
+ * boards in this way is optional, and completely driver-dependent.
+ * Some drivers use arrays such as this, other do not.
+ */
+struct cb_pcidda_board {
+       const char *name;
+       char status;            // Driver status:
+       // 0 - tested
+       // 1 - manual read, not tested
+       // 2 - manual not read
+       unsigned short device_id;
+       int ao_chans;
+       int ao_bits;
+       const struct comedi_lrange *ranges;
+};
+static const struct cb_pcidda_board cb_pcidda_boards[] = {
+       {
+             name:     "pci-dda02/12",
+             status:   1,
+             device_id:0x20,
+             ao_chans:2,
+             ao_bits:  12,
+             ranges:   &cb_pcidda_ranges,
+               },
+       {
+             name:     "pci-dda04/12",
+             status:   1,
+             device_id:0x21,
+             ao_chans:4,
+             ao_bits:  12,
+             ranges:   &cb_pcidda_ranges,
+               },
+       {
+             name:     "pci-dda08/12",
+             status:   0,
+             device_id:0x22,
+             ao_chans:8,
+             ao_bits:  12,
+             ranges:   &cb_pcidda_ranges,
+               },
+       {
+             name:     "pci-dda02/16",
+             status:   2,
+             device_id:0x23,
+             ao_chans:2,
+             ao_bits:  16,
+             ranges:   &cb_pcidda_ranges,
+               },
+       {
+             name:     "pci-dda04/16",
+             status:   2,
+             device_id:0x24,
+             ao_chans:4,
+             ao_bits:  16,
+             ranges:   &cb_pcidda_ranges,
+               },
+       {
+             name:     "pci-dda08/16",
+             status:   0,
+             device_id:0x25,
+             ao_chans:8,
+             ao_bits:  16,
+             ranges:   &cb_pcidda_ranges,
+               },
+};
+
+static DEFINE_PCI_DEVICE_TABLE(cb_pcidda_pci_table) = {
+       {PCI_VENDOR_ID_CB, 0x0020, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {PCI_VENDOR_ID_CB, 0x0021, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {PCI_VENDOR_ID_CB, 0x0022, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {PCI_VENDOR_ID_CB, 0x0023, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {PCI_VENDOR_ID_CB, 0x0024, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {PCI_VENDOR_ID_CB, 0x0025, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+       {0}
+};
+
+MODULE_DEVICE_TABLE(pci, cb_pcidda_pci_table);
+
+/*
+ * Useful for shorthand access to the particular board structure
+ */
+#define thisboard ((const struct cb_pcidda_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_pcidda_private {
+       int data;
+
+       /* would be useful for a PCI device */
+       struct pci_dev *pci_dev;
+
+       unsigned long digitalio;
+       unsigned long dac;
+       //unsigned long control_status;
+       //unsigned long adc_fifo;
+       unsigned int dac_cal1_bits;     // bits last written to da calibration register 1
+       unsigned int ao_range[MAX_AO_CHANNELS]; // current range settings for output channels
+       u16 eeprom_data[EEPROM_SIZE];   // software copy of board's eeprom
+};
+
+/*
+ * most drivers define the following macro to make it easy to
+ * access the private structure.
+ */
+#define devpriv ((struct cb_pcidda_private *)dev->private)
+
+static int cb_pcidda_attach(struct comedi_device * dev, struct comedi_devconfig * it);
+static int cb_pcidda_detach(struct comedi_device * dev);
+//static int cb_pcidda_ai_rinsn(struct comedi_device *dev,struct comedi_subdevice *s,struct comedi_insn *insn,unsigned int *data);
+static int cb_pcidda_ao_winsn(struct comedi_device * dev, struct comedi_subdevice * s,
+       struct comedi_insn * insn, unsigned int * data);
+//static int cb_pcidda_ai_cmd(struct comedi_device *dev,struct comedi_subdevice *s);
+//static int cb_pcidda_ai_cmdtest(struct comedi_device *dev,struct comedi_subdevice *s, struct comedi_cmd *cmd);
+//static int cb_pcidda_ns_to_timer(unsigned int *ns,int round);
+static unsigned int cb_pcidda_serial_in(struct comedi_device * dev);
+static void cb_pcidda_serial_out(struct comedi_device * dev, unsigned int value,
+       unsigned int num_bits);
+static unsigned int cb_pcidda_read_eeprom(struct comedi_device * dev,
+       unsigned int address);
+static void cb_pcidda_calibrate(struct comedi_device * dev, unsigned int channel,
+       unsigned int range);
+
+/*
+ * 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 struct comedi_driver driver_cb_pcidda = {
+      driver_name:"cb_pcidda",
+      module:THIS_MODULE,
+      attach:cb_pcidda_attach,
+      detach:cb_pcidda_detach,
+};
+
+/*
+ * Attach is called by the Comedi core to configure the driver
+ * for a particular board.
+ */
+static int cb_pcidda_attach(struct comedi_device * dev, struct comedi_devconfig * it)
+{
+       struct comedi_subdevice *s;
+       struct pci_dev *pcidev;
+       int index;
+
+       printk("comedi%d: cb_pcidda: ", dev->minor);
+
+/*
+ * Allocate the private structure area.
+ */
+       if (alloc_private(dev, sizeof(struct cb_pcidda_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)) {
+               if (pcidev->vendor == PCI_VENDOR_ID_CB) {
+                       if (it->options[0] || it->options[1]) {
+                               if (pcidev->bus->number != it->options[0] ||
+                                       PCI_SLOT(pcidev->devfn) !=
+                                       it->options[1]) {
+                                       continue;
+                               }
+                       }
+                       for (index = 0; index < N_BOARDS; index++) {
+                               if (cb_pcidda_boards[index].device_id ==
+                                       pcidev->device) {
+                                       goto found;
+                               }
+                       }
+               }
+       }
+       if (!pcidev) {
+               printk("Not a ComputerBoards/MeasurementComputing card on requested position\n");
+               return -EIO;
+       }
+      found:
+       devpriv->pci_dev = pcidev;
+       dev->board_ptr = cb_pcidda_boards + index;
+       // "thisboard" macro can be used from here.
+       printk("Found %s at requested position\n", thisboard->name);
+
+       /*
+        * Enable PCI device and request regions.
+        */
+       if (comedi_pci_enable(pcidev, thisboard->name)) {
+               printk("cb_pcidda: failed to enable PCI device and request regions\n");
+               return -EIO;
+       }
+
+/*
+ * Allocate the I/O ports.
+ */
+       devpriv->digitalio =
+               pci_resource_start(devpriv->pci_dev, DIGITALIO_BADRINDEX);
+       devpriv->dac = pci_resource_start(devpriv->pci_dev, DAC_BADRINDEX);
+
+/*
+ * Warn about the status of the driver.
+ */
+       if (thisboard->status == 2)
+               printk("WARNING: DRIVER FOR THIS BOARD NOT CHECKED WITH MANUAL. " "WORKS ASSUMING FULL COMPATIBILITY WITH PCI-DDA08/12. " "PLEASE REPORT USAGE TO <ivanmr@altavista.com>.\n");
+
+/*
+ * Initialize dev->board_name.
+ */
+       dev->board_name = thisboard->name;
+
+/*
+ * Allocate the subdevice structures.
+ */
+       if (alloc_subdevices(dev, 3) < 0)
+               return -ENOMEM;
+
+       s = dev->subdevices + 0;
+       /* analog output subdevice */
+       s->type = COMEDI_SUBD_AO;
+       s->subdev_flags = SDF_WRITABLE;
+       s->n_chan = thisboard->ao_chans;
+       s->maxdata = (1 << thisboard->ao_bits) - 1;
+       s->range_table = thisboard->ranges;
+       s->insn_write = cb_pcidda_ao_winsn;
+//      s->subdev_flags |= SDF_CMD_READ;
+//      s->do_cmd = cb_pcidda_ai_cmd;
+//      s->do_cmdtest = cb_pcidda_ai_cmdtest;
+
+       // two 8255 digital io subdevices
+       s = dev->subdevices + 1;
+       subdev_8255_init(dev, s, NULL, devpriv->digitalio);
+       s = dev->subdevices + 2;
+       subdev_8255_init(dev, s, NULL, devpriv->digitalio + PORT2A);
+
+       printk(" eeprom:");
+       for (index = 0; index < EEPROM_SIZE; index++) {
+               devpriv->eeprom_data[index] = cb_pcidda_read_eeprom(dev, index);
+               printk(" %i:0x%x ", index, devpriv->eeprom_data[index]);
+       }
+       printk("\n");
+
+       // set calibrations dacs
+       for (index = 0; index < thisboard->ao_chans; index++)
+               cb_pcidda_calibrate(dev, index, devpriv->ao_range[index]);
+
+       return 1;
+}
+
+/*
+ * _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_pcidda_detach(struct comedi_device * dev)
+{
+/*
+ * Deallocate the I/O ports.
+ */
+       if (devpriv) {
+               if (devpriv->pci_dev) {
+                       if (devpriv->dac) {
+                               comedi_pci_disable(devpriv->pci_dev);
+                       }
+                       pci_dev_put(devpriv->pci_dev);
+               }
+       }
+       // cleanup 8255
+       if (dev->subdevices) {
+               subdev_8255_cleanup(dev, dev->subdevices + 1);
+               subdev_8255_cleanup(dev, dev->subdevices + 2);
+       }
+
+       printk("comedi%d: cb_pcidda: remove\n", dev->minor);
+
+       return 0;
+}
+
+/*
+ * I will program this later... ;-)
+ */
+#if 0
+static int cb_pcidda_ai_cmd(struct comedi_device * dev, struct comedi_subdevice * s)
+{
+       printk("cb_pcidda_ai_cmd\n");
+       printk("subdev: %d\n", cmd->subdev);
+       printk("flags: %d\n", cmd->flags);
+       printk("start_src: %d\n", cmd->start_src);
+       printk("start_arg: %d\n", cmd->start_arg);
+       printk("scan_begin_src: %d\n", cmd->scan_begin_src);
+       printk("convert_src: %d\n", cmd->convert_src);
+       printk("convert_arg: %d\n", cmd->convert_arg);
+       printk("scan_end_src: %d\n", cmd->scan_end_src);
+       printk("scan_end_arg: %d\n", cmd->scan_end_arg);
+       printk("stop_src: %d\n", cmd->stop_src);
+       printk("stop_arg: %d\n", cmd->stop_arg);
+       printk("chanlist_len: %d\n", cmd->chanlist_len);
+}
+#endif
+
+#if 0
+static int cb_pcidda_ai_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_NOW;
+       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_TIMER | 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 */
+
+       /* note that mutual compatiblity is not an issue here */
+       if (cmd->scan_begin_src != TRIG_TIMER
+               && cmd->scan_begin_src != TRIG_EXT)
+               err++;
+       if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
+               err++;
+       if (cmd->stop_src != TRIG_TIMER && cmd->stop_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++;
+       }
+#define MAX_SPEED      10000   /* in nanoseconds */
+#define MIN_SPEED      1000000000      /* in nanoseconds */
+
+       if (cmd->scan_begin_src == TRIG_TIMER) {
+               if (cmd->scan_begin_arg < MAX_SPEED) {
+                       cmd->scan_begin_arg = MAX_SPEED;
+                       err++;
+               }
+               if (cmd->scan_begin_arg > MIN_SPEED) {
+                       cmd->scan_begin_arg = MIN_SPEED;
+                       err++;
+               }
+       } else {
+               /* external trigger */
+               /* should be level/edge, hi/lo specification here */
+               /* should specify multiple external triggers */
+               if (cmd->scan_begin_arg > 9) {
+                       cmd->scan_begin_arg = 9;
+                       err++;
+               }
+       }
+       if (cmd->convert_src == TRIG_TIMER) {
+               if (cmd->convert_arg < MAX_SPEED) {
+                       cmd->convert_arg = MAX_SPEED;
+                       err++;
+               }
+               if (cmd->convert_arg > MIN_SPEED) {
+                       cmd->convert_arg = MIN_SPEED;
+                       err++;
+               }
+       } else {
+               /* external trigger */
+               /* see above */
+               if (cmd->convert_arg > 9) {
+                       cmd->convert_arg = 9;
+                       err++;
+               }
+       }
+
+       if (cmd->scan_end_arg != cmd->chanlist_len) {
+               cmd->scan_end_arg = cmd->chanlist_len;
+               err++;
+       }
+       if (cmd->stop_src == TRIG_COUNT) {
+               if (cmd->stop_arg > 0x00ffffff) {
+                       cmd->stop_arg = 0x00ffffff;
+                       err++;
+               }
+       } else {
+               /* 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;
+               cb_pcidda_ns_to_timer(&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;
+               cb_pcidda_ns_to_timer(&cmd->convert_arg,
+                       cmd->flags & TRIG_ROUND_MASK);
+               if (tmp != cmd->convert_arg)
+                       err++;
+               if (cmd->scan_begin_src == TRIG_TIMER &&
+                       cmd->scan_begin_arg <
+                       cmd->convert_arg * cmd->scan_end_arg) {
+                       cmd->scan_begin_arg =
+                               cmd->convert_arg * cmd->scan_end_arg;
+                       err++;
+               }
+       }
+
+       if (err)
+               return 4;
+
+       return 0;
+}
+#endif
+
+/* This function doesn't require a particular form, this is just
+ * what happens to be used in some of the drivers.  It should
+ * convert ns nanoseconds to a counter value suitable for programming
+ * the device.  Also, it should adjust ns so that it cooresponds to
+ * the actual time that the device will use. */
+#if 0
+static int cb_pcidda_ns_to_timer(unsigned int *ns, int round)
+{
+       /* trivial timer */
+       return *ns;
+}
+#endif
+
+static int cb_pcidda_ao_winsn(struct comedi_device * dev, struct comedi_subdevice * s,
+       struct comedi_insn * insn, unsigned int * data)
+{
+       unsigned int command;
+       unsigned int channel, range;
+
+       channel = CR_CHAN(insn->chanspec);
+       range = CR_RANGE(insn->chanspec);
+
+       // adjust calibration dacs if range has changed
+       if (range != devpriv->ao_range[channel])
+               cb_pcidda_calibrate(dev, channel, range);
+
+       /* output channel configuration */
+       command = NOSU | ENABLEDAC;
+
+       /* output channel range */
+       switch (range) {
+       case 0:
+               command |= BIP | RANGE10V;
+               break;
+       case 1:
+               command |= BIP | RANGE5V;
+               break;
+       case 2:
+               command |= BIP | RANGE2V5;
+               break;
+       case 3:
+               command |= UNIP | RANGE10V;
+               break;
+       case 4:
+               command |= UNIP | RANGE5V;
+               break;
+       case 5:
+               command |= UNIP | RANGE2V5;
+               break;
+       };
+
+       /* output channel specification */
+       command |= channel << 2;
+       outw(command, devpriv->dac + DACONTROL);
+
+       /* write data */
+       outw(data[0], devpriv->dac + DADATA + channel * 2);
+
+       /* return the number of samples read/written */
+       return 1;
+}
+
+// lowlevel read from eeprom
+static unsigned int cb_pcidda_serial_in(struct comedi_device * dev)
+{
+       unsigned int value = 0;
+       int i;
+       const int value_width = 16;     // number of bits wide values are
+
+       for (i = 1; i <= value_width; i++) {
+               // read bits most significant bit first
+               if (inw_p(devpriv->dac + DACALIBRATION1) & SERIAL_OUT_BIT) {
+                       value |= 1 << (value_width - i);
+               }
+       }
+
+       return value;
+}
+
+// lowlevel write to eeprom/dac
+static void cb_pcidda_serial_out(struct comedi_device * dev, unsigned int value,
+       unsigned int num_bits)
+{
+       int i;
+
+       for (i = 1; i <= num_bits; i++) {
+               // send bits most significant bit first
+               if (value & (1 << (num_bits - i)))
+                       devpriv->dac_cal1_bits |= SERIAL_IN_BIT;
+               else
+                       devpriv->dac_cal1_bits &= ~SERIAL_IN_BIT;
+               outw_p(devpriv->dac_cal1_bits, devpriv->dac + DACALIBRATION1);
+       }
+}
+
+// reads a 16 bit value from board's eeprom
+static unsigned int cb_pcidda_read_eeprom(struct comedi_device * dev,
+       unsigned int address)
+{
+       unsigned int i;
+       unsigned int cal2_bits;
+       unsigned int value;
+       const int max_num_caldacs = 4;  // one caldac for every two dac channels
+       const int read_instruction = 0x6;       // bits to send to tell eeprom we want to read
+       const int instruction_length = 3;
+       const int address_length = 8;
+
+       // send serial output stream to eeprom
+       cal2_bits = SELECT_EEPROM_BIT | DESELECT_REF_DAC_BIT | DUMMY_BIT;
+       // deactivate caldacs (one caldac for every two channels)
+       for (i = 0; i < max_num_caldacs; i++) {
+               cal2_bits |= DESELECT_CALDAC_BIT(i);
+       }
+       outw_p(cal2_bits, devpriv->dac + DACALIBRATION2);
+
+       // tell eeprom we want to read
+       cb_pcidda_serial_out(dev, read_instruction, instruction_length);
+       // send address we want to read from
+       cb_pcidda_serial_out(dev, address, address_length);
+
+       value = cb_pcidda_serial_in(dev);
+
+       // deactivate eeprom
+       cal2_bits &= ~SELECT_EEPROM_BIT;
+       outw_p(cal2_bits, devpriv->dac + DACALIBRATION2);
+
+       return value;
+}
+
+// writes to 8 bit calibration dacs
+static void cb_pcidda_write_caldac(struct comedi_device * dev, unsigned int caldac,
+       unsigned int channel, unsigned int value)
+{
+       unsigned int cal2_bits;
+       unsigned int i;
+       const int num_channel_bits = 3; // caldacs use 3 bit channel specification
+       const int num_caldac_bits = 8;  // 8 bit calibration dacs
+       const int max_num_caldacs = 4;  // one caldac for every two dac channels
+
+       /* write 3 bit channel */
+       cb_pcidda_serial_out(dev, channel, num_channel_bits);
+       // write 8 bit caldac value
+       cb_pcidda_serial_out(dev, value, num_caldac_bits);
+
+       // latch stream into appropriate caldac
+       // deselect reference dac
+       cal2_bits = DESELECT_REF_DAC_BIT | DUMMY_BIT;
+       // deactivate caldacs (one caldac for every two channels)
+       for (i = 0; i < max_num_caldacs; i++) {
+               cal2_bits |= DESELECT_CALDAC_BIT(i);
+       }
+       // activate the caldac we want
+       cal2_bits &= ~DESELECT_CALDAC_BIT(caldac);
+       outw_p(cal2_bits, devpriv->dac + DACALIBRATION2);
+       // deactivate caldac
+       cal2_bits |= DESELECT_CALDAC_BIT(caldac);
+       outw_p(cal2_bits, devpriv->dac + DACALIBRATION2);
+}
+
+// returns caldac that calibrates given analog out channel
+static unsigned int caldac_number(unsigned int channel)
+{
+       return channel / 2;
+}
+
+// returns caldac channel that provides fine gain for given ao channel
+static unsigned int fine_gain_channel(unsigned int ao_channel)
+{
+       return 4 * (ao_channel % 2);
+}
+
+// returns caldac channel that provides coarse gain for given ao channel
+static unsigned int coarse_gain_channel(unsigned int ao_channel)
+{
+       return 1 + 4 * (ao_channel % 2);
+}
+
+// returns caldac channel that provides coarse offset for given ao channel
+static unsigned int coarse_offset_channel(unsigned int ao_channel)
+{
+       return 2 + 4 * (ao_channel % 2);
+}
+
+// returns caldac channel that provides fine offset for given ao channel
+static unsigned int fine_offset_channel(unsigned int ao_channel)
+{
+       return 3 + 4 * (ao_channel % 2);
+}
+
+// returns eeprom address that provides offset for given ao channel and range
+static unsigned int offset_eeprom_address(unsigned int ao_channel,
+       unsigned int range)
+{
+       return 0x7 + 2 * range + 12 * ao_channel;
+}
+
+// returns eeprom address that provides gain calibration for given ao channel and range
+static unsigned int gain_eeprom_address(unsigned int ao_channel,
+       unsigned int range)
+{
+       return 0x8 + 2 * range + 12 * ao_channel;
+}
+
+// returns upper byte of eeprom entry, which gives the coarse adjustment values
+static unsigned int eeprom_coarse_byte(unsigned int word)
+{
+       return (word >> 8) & 0xff;
+}
+
+// returns lower byte of eeprom entry, which gives the fine adjustment values
+static unsigned int eeprom_fine_byte(unsigned int word)
+{
+       return word & 0xff;
+}
+
+// set caldacs to eeprom values for given channel and range
+static void cb_pcidda_calibrate(struct comedi_device * dev, unsigned int channel,
+       unsigned int range)
+{
+       unsigned int coarse_offset, fine_offset, coarse_gain, fine_gain;
+
+       // remember range so we can tell when we need to readjust calibration
+       devpriv->ao_range[channel] = range;
+
+       // get values from eeprom data
+       coarse_offset =
+               eeprom_coarse_byte(devpriv->
+               eeprom_data[offset_eeprom_address(channel, range)]);
+       fine_offset =
+               eeprom_fine_byte(devpriv->
+               eeprom_data[offset_eeprom_address(channel, range)]);
+       coarse_gain =
+               eeprom_coarse_byte(devpriv->
+               eeprom_data[gain_eeprom_address(channel, range)]);
+       fine_gain =
+               eeprom_fine_byte(devpriv->
+               eeprom_data[gain_eeprom_address(channel, range)]);
+
+       // set caldacs
+       cb_pcidda_write_caldac(dev, caldac_number(channel),
+               coarse_offset_channel(channel), coarse_offset);
+       cb_pcidda_write_caldac(dev, caldac_number(channel),
+               fine_offset_channel(channel), fine_offset);
+       cb_pcidda_write_caldac(dev, caldac_number(channel),
+               coarse_gain_channel(channel), coarse_gain);
+       cb_pcidda_write_caldac(dev, caldac_number(channel),
+               fine_gain_channel(channel), fine_gain);
+}
+
+/*
+ * A convenient macro that defines init_module() and cleanup_module(),
+ * as necessary.
+ */
+COMEDI_PCI_INITCLEANUP(driver_cb_pcidda, cb_pcidda_pci_table);