drivers/staging/comedi/drivers/pcmda12.c

   1 /*
   2     comedi/drivers/pcmda12.c
   3     Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board.
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 2006 Calin A. Culianu <calin@ajvar.org>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22 /*
  23 Driver: pcmda12
  24 Description: A driver for the Winsystems PCM-D/A-12
  25 Devices: [Winsystems] PCM-D/A-12 (pcmda12)
  26 Author: Calin Culianu <calin@ajvar.org>
  27 Updated: Fri, 13 Jan 2006 12:01:01 -0500
  28 Status: works
  29
  30 A driver for the relatively straightforward-to-program PCM-D/A-12.
  31 This board doesn't support commands, and the only way to set its
  32 analog output range is to jumper the board.  As such,
  33 comedi_data_write() ignores the range value specified.
  34
  35 The board uses 16 consecutive I/O addresses starting at the I/O port
  36 base address.  Each address corresponds to the LSB then MSB of a
  37 particular channel from 0-7.
  38
  39 Note that the board is not ISA-PNP capable and thus
  40 needs the I/O port comedi_config parameter.
  41
  42 Note that passing a nonzero value as the second config option will
  43 enable "simultaneous xfer" mode for this board, in which AO writes
  44 will not take effect until a subsequent read of any AO channel.  This
  45 is so that one can speed up programming by preloading all AO registers
  46 with values before simultaneously setting them to take effect with one
  47 read command.
  48
  49 Configuration Options:
  50   [0] - I/O port base address
  51   [1] - Do Simultaneous Xfer (see description)
  52 */
  53
  54 #include "../comedidev.h"
  55
  56 #include <linux/pci.h>          /* for PCI devices */
  57
  58 #define MIN(a,b) ( ((a) < (b)) ? (a) : (b) )
  59 #define SDEV_NO ((int)(s - dev->subdevices))
  60 #define CHANS 8
  61 #define IOSIZE 16
  62 #define LSB(x) ((unsigned char)((x) & 0xff))
  63 #define MSB(x) ((unsigned char)((((unsigned short)(x))>>8) & 0xff))
  64 #define LSB_PORT(chan) (dev->iobase + (chan)*2)
  65 #define MSB_PORT(chan) (LSB_PORT(chan)+1)
  66 #define BITS 12
  67
  68 /*
  69  * Bords
  70  */
  71 typedef struct pcmda12_board_struct {
  72         const char *name;
  73 } pcmda12_board;
  74
  75 /* note these have no effect and are merely here for reference..
  76    these are configured by jumpering the board! */
  77 static const comedi_lrange pcmda12_ranges = {
  78         3,
  79         {
  80                         UNI_RANGE(5), UNI_RANGE(10), BIP_RANGE(5)
  81                 }
  82 };
  83
  84 static const pcmda12_board pcmda12_boards[] = {
  85         {
  86               name:     "pcmda12",
  87                 },
  88 };
  89
  90 /*
  91  * Useful for shorthand access to the particular board structure
  92  */
  93 #define thisboard ((const pcmda12_board *)dev->board_ptr)
  94
  95 typedef struct {
  96         unsigned int ao_readback[CHANS];
  97         int simultaneous_xfer_mode;
  98 } pcmda12_private;
  99
 100 #define devpriv ((pcmda12_private *)(dev->private))
 101
 102 /*
 103  * The comedi_driver structure tells the Comedi core module
 104  * which functions to call to configure/deconfigure (attach/detach)
 105  * the board, and also about the kernel module that contains
 106  * the device code.
 107  */
 108 static int pcmda12_attach(comedi_device * dev, comedi_devconfig * it);
 109 static int pcmda12_detach(comedi_device * dev);
 110
 111 static void zero_chans(comedi_device * dev);
 112
 113 static comedi_driver driver = {
 114       driver_name:"pcmda12",
 115       module:THIS_MODULE,
 116       attach:pcmda12_attach,
 117       detach:pcmda12_detach,
 118 /* It is not necessary to implement the following members if you are
 119  * writing a driver for a ISA PnP or PCI card */
 120         /* Most drivers will support multiple types of boards by
 121          * having an array of board structures.  These were defined
 122          * in pcmda12_boards[] above.  Note that the element 'name'
 123          * was first in the structure -- Comedi uses this fact to
 124          * extract the name of the board without knowing any details
 125          * about the structure except for its length.
 126          * When a device is attached (by comedi_config), the name
 127          * of the device is given to Comedi, and Comedi tries to
 128          * match it by going through the list of board names.  If
 129          * there is a match, the address of the pointer is put
 130          * into dev->board_ptr and driver->attach() is called.
 131          *
 132          * Note that these are not necessary if you can determine
 133          * the type of board in software.  ISA PnP, PCI, and PCMCIA
 134          * devices are such boards.
 135          */
 136       board_name:&pcmda12_boards[0].name,
 137       offset:sizeof(pcmda12_board),
 138       num_names:sizeof(pcmda12_boards) / sizeof(pcmda12_board),
 139 };
 140
 141 static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
 142         comedi_insn * insn, unsigned int * data);
 143 static int ao_rinsn(comedi_device * dev, comedi_subdevice * s,
 144         comedi_insn * insn, unsigned int * data);
 145
 146 /*
 147  * Attach is called by the Comedi core to configure the driver
 148  * for a particular board.  If you specified a board_name array
 149  * in the driver structure, dev->board_ptr contains that
 150  * address.
 151  */
 152 static int pcmda12_attach(comedi_device * dev, comedi_devconfig * it)
 153 {
 154         comedi_subdevice *s;
 155         unsigned long iobase;
 156
 157         iobase = it->options[0];
 158         printk("comedi%d: %s: io: %lx %s ", dev->minor, driver.driver_name,
 159                 iobase, it->options[1] ? "simultaneous xfer mode enabled" : "");
 160
 161         if (!request_region(iobase, IOSIZE, driver.driver_name)) {
 162                 printk("I/O port conflict\n");
 163                 return -EIO;
 164         }
 165         dev->iobase = iobase;
 166
 167 /*
 168  * Initialize dev->board_name.  Note that we can use the "thisboard"
 169  * macro now, since we just initialized it in the last line.
 170  */
 171         dev->board_name = thisboard->name;
 172
 173 /*
 174  * Allocate the private structure area.  alloc_private() is a
 175  * convenient macro defined in comedidev.h.
 176  */
 177         if (alloc_private(dev, sizeof(pcmda12_private)) < 0) {
 178                 printk("cannot allocate private data structure\n");
 179                 return -ENOMEM;
 180         }
 181
 182         devpriv->simultaneous_xfer_mode = it->options[1];
 183
 184         /*
 185          * Allocate the subdevice structures.  alloc_subdevice() is a
 186          * convenient macro defined in comedidev.h.
 187          *
 188          * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the
 189          * 96-channel version of the board.
 190          */
 191         if (alloc_subdevices(dev, 1) < 0) {
 192                 printk("cannot allocate subdevice data structures\n");
 193                 return -ENOMEM;
 194         }
 195
 196         s = dev->subdevices;
 197         s->private = NULL;
 198         s->maxdata = (0x1 << BITS) - 1;
 199         s->range_table = &pcmda12_ranges;
 200         s->type = COMEDI_SUBD_AO;
 201         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 202         s->n_chan = CHANS;
 203         s->insn_write = &ao_winsn;
 204         s->insn_read = &ao_rinsn;
 205
 206         zero_chans(dev);        /* clear out all the registers, basically */
 207
 208         printk("attached\n");
 209
 210         return 1;
 211 }
 212
 213 /*
 214  * _detach is called to deconfigure a device.  It should deallocate
 215  * resources.
 216  * This function is also called when _attach() fails, so it should be
 217  * careful not to release resources that were not necessarily
 218  * allocated by _attach().  dev->private and dev->subdevices are
 219  * deallocated automatically by the core.
 220  */
 221 static int pcmda12_detach(comedi_device * dev)
 222 {
 223         printk("comedi%d: %s: remove\n", dev->minor, driver.driver_name);
 224         if (dev->iobase)
 225                 release_region(dev->iobase, IOSIZE);
 226         return 0;
 227 }
 228
 229 static void zero_chans(comedi_device * dev)
 230 {                               /* sets up an
 231                                    ASIC chip to defaults */
 232         int i;
 233         for (i = 0; i < CHANS; ++i) {
 234 /*      /\* do this as one instruction?? *\/ */
 235 /*      outw(0, LSB_PORT(chan)); */
 236                 outb(0, LSB_PORT(i));
 237                 outb(0, MSB_PORT(i));
 238         }
 239         inb(LSB_PORT(0));       /* update chans. */
 240 }
 241
 242 static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
 243         comedi_insn * insn, unsigned int * data)
 244 {
 245         int i;
 246         int chan = CR_CHAN(insn->chanspec);
 247
 248         /* Writing a list of values to an AO channel is probably not
 249          * very useful, but that's how the interface is defined. */
 250         for (i = 0; i < insn->n; ++i) {
 251
 252 /*      /\* do this as one instruction?? *\/ */
 253 /*      outw(data[i], LSB_PORT(chan)); */
 254
 255                 /* Need to do this as two instructions due to 8-bit bus?? */
 256                 /*  first, load the low byte */
 257                 outb(LSB(data[i]), LSB_PORT(chan));
 258                 /*  next, write the high byte */
 259                 outb(MSB(data[i]), MSB_PORT(chan));
 260
 261                 /* save shadow register */
 262                 devpriv->ao_readback[chan] = data[i];
 263
 264                 if (!devpriv->simultaneous_xfer_mode)
 265                         inb(LSB_PORT(chan));
 266         }
 267
 268         /* return the number of samples written */
 269         return i;
 270 }
 271
 272 /* AO subdevices should have a read insn as well as a write insn.
 273
 274    Usually this means copying a value stored in devpriv->ao_readback.
 275    However, since this driver supports simultaneous xfer then sometimes
 276    this function actually accomplishes work.
 277
 278    Simultaneaous xfer mode is accomplished by loading ALL the values
 279    you want for AO in all the channels, then READing off one of the AO
 280    registers to initiate the instantaneous simultaneous update of all
 281    DAC outputs, which makes all AO channels update simultaneously.
 282    This is useful for some control applications, I would imagine.
 283 */
 284 static int ao_rinsn(comedi_device * dev, comedi_subdevice * s,
 285         comedi_insn * insn, unsigned int * data)
 286 {
 287         int i;
 288         int chan = CR_CHAN(insn->chanspec);
 289
 290         for (i = 0; i < insn->n; i++) {
 291                 if (devpriv->simultaneous_xfer_mode)
 292                         inb(LSB_PORT(chan));
 293                 /* read back shadow register */
 294                 data[i] = devpriv->ao_readback[chan];
 295         }
 296
 297         return i;
 298 }
 299
 300 /*
 301  * A convenient macro that defines init_module() and cleanup_module(),
 302  * as necessary.
 303  */
 304 COMEDI_INITCLEANUP(driver);