2 comedi/drivers/pcmda12.c
3 Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board.
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 2006 Calin A. Culianu <calin@ajvar.org>
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.
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.
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.
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
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.
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.
39 Note that the board is not ISA-PNP capable and thus
40 needs the I/O port comedi_config parameter.
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
49 Configuration Options:
50 [0] - I/O port base address
51 [1] - Do Simultaneous Xfer (see description)
54 #include "../comedidev.h"
56 #include <linux/pci.h> /* for PCI devices */
58 #define SDEV_NO ((int)(s - dev->subdevices))
61 #define LSB(x) ((unsigned char)((x) & 0xff))
62 #define MSB(x) ((unsigned char)((((unsigned short)(x))>>8) & 0xff))
63 #define LSB_PORT(chan) (dev->iobase + (chan)*2)
64 #define MSB_PORT(chan) (LSB_PORT(chan)+1)
70 struct pcmda12_board {
74 /* note these have no effect and are merely here for reference..
75 these are configured by jumpering the board! */
76 static const struct comedi_lrange pcmda12_ranges = {
79 UNI_RANGE(5), UNI_RANGE(10), BIP_RANGE(5)
83 static const struct pcmda12_board pcmda12_boards[] = {
90 * Useful for shorthand access to the particular board structure
92 #define thisboard ((const struct pcmda12_board *)dev->board_ptr)
94 struct pcmda12_private {
96 unsigned int ao_readback[CHANS];
97 int simultaneous_xfer_mode;
100 #define devpriv ((struct pcmda12_private *)(dev->private))
103 * The struct 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
108 static int pcmda12_attach(struct comedi_device *dev,
109 struct comedi_devconfig *it);
110 static int pcmda12_detach(struct comedi_device *dev);
112 static void zero_chans(struct comedi_device *dev);
114 static struct comedi_driver driver = {
115 .driver_name = "pcmda12",
116 .module = THIS_MODULE,
117 .attach = pcmda12_attach,
118 .detach = pcmda12_detach,
119 /* It is not necessary to implement the following members if you are
120 * writing a driver for a ISA PnP or PCI card */
121 /* Most drivers will support multiple types of boards by
122 * having an array of board structures. These were defined
123 * in pcmda12_boards[] above. Note that the element 'name'
124 * was first in the structure -- Comedi uses this fact to
125 * extract the name of the board without knowing any details
126 * about the structure except for its length.
127 * When a device is attached (by comedi_config), the name
128 * of the device is given to Comedi, and Comedi tries to
129 * match it by going through the list of board names. If
130 * there is a match, the address of the pointer is put
131 * into dev->board_ptr and driver->attach() is called.
133 * Note that these are not necessary if you can determine
134 * the type of board in software. ISA PnP, PCI, and PCMCIA
135 * devices are such boards.
137 .board_name = &pcmda12_boards[0].name,
138 .offset = sizeof(struct pcmda12_board),
139 .num_names = ARRAY_SIZE(pcmda12_boards),
142 static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
143 struct comedi_insn *insn, unsigned int *data);
144 static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
145 struct comedi_insn *insn, unsigned int *data);
148 * Attach is called by the Comedi core to configure the driver
149 * for a particular board. If you specified a board_name array
150 * in the driver structure, dev->board_ptr contains that
153 static int pcmda12_attach(struct comedi_device *dev,
154 struct comedi_devconfig *it)
156 struct comedi_subdevice *s;
157 unsigned long iobase;
159 iobase = it->options[0];
161 "comedi%d: %s: io: %lx %s ", dev->minor, driver.driver_name,
162 iobase, it->options[1] ? "simultaneous xfer mode enabled" : "");
164 if (!request_region(iobase, IOSIZE, driver.driver_name)) {
165 printk("I/O port conflict\n");
168 dev->iobase = iobase;
171 * Initialize dev->board_name. Note that we can use the "thisboard"
172 * macro now, since we just initialized it in the last line.
174 dev->board_name = thisboard->name;
177 * Allocate the private structure area. alloc_private() is a
178 * convenient macro defined in comedidev.h.
180 if (alloc_private(dev, sizeof(struct pcmda12_private)) < 0) {
181 printk(KERN_ERR "cannot allocate private data structure\n");
185 devpriv->simultaneous_xfer_mode = it->options[1];
188 * Allocate the subdevice structures. alloc_subdevice() is a
189 * convenient macro defined in comedidev.h.
191 * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the
192 * 96-channel version of the board.
194 if (alloc_subdevices(dev, 1) < 0) {
195 printk(KERN_ERR "cannot allocate subdevice data structures\n");
201 s->maxdata = (0x1 << BITS) - 1;
202 s->range_table = &pcmda12_ranges;
203 s->type = COMEDI_SUBD_AO;
204 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
206 s->insn_write = &ao_winsn;
207 s->insn_read = &ao_rinsn;
209 zero_chans(dev); /* clear out all the registers, basically */
211 printk(KERN_INFO "attached\n");
217 * _detach is called to deconfigure a device. It should deallocate
219 * This function is also called when _attach() fails, so it should be
220 * careful not to release resources that were not necessarily
221 * allocated by _attach(). dev->private and dev->subdevices are
222 * deallocated automatically by the core.
224 static int pcmda12_detach(struct comedi_device *dev)
227 "comedi%d: %s: remove\n", dev->minor, driver.driver_name);
229 release_region(dev->iobase, IOSIZE);
233 static void zero_chans(struct comedi_device *dev)
235 ASIC chip to defaults */
237 for (i = 0; i < CHANS; ++i) {
238 /* /\* do this as one instruction?? *\/ */
239 /* outw(0, LSB_PORT(chan)); */
240 outb(0, LSB_PORT(i));
241 outb(0, MSB_PORT(i));
243 inb(LSB_PORT(0)); /* update chans. */
246 static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
247 struct comedi_insn *insn, unsigned int *data)
250 int chan = CR_CHAN(insn->chanspec);
252 /* Writing a list of values to an AO channel is probably not
253 * very useful, but that's how the interface is defined. */
254 for (i = 0; i < insn->n; ++i) {
256 /* /\* do this as one instruction?? *\/ */
257 /* outw(data[i], LSB_PORT(chan)); */
259 /* Need to do this as two instructions due to 8-bit bus?? */
260 /* first, load the low byte */
261 outb(LSB(data[i]), LSB_PORT(chan));
262 /* next, write the high byte */
263 outb(MSB(data[i]), MSB_PORT(chan));
265 /* save shadow register */
266 devpriv->ao_readback[chan] = data[i];
268 if (!devpriv->simultaneous_xfer_mode)
272 /* return the number of samples written */
276 /* AO subdevices should have a read insn as well as a write insn.
278 Usually this means copying a value stored in devpriv->ao_readback.
279 However, since this driver supports simultaneous xfer then sometimes
280 this function actually accomplishes work.
282 Simultaneaous xfer mode is accomplished by loading ALL the values
283 you want for AO in all the channels, then READing off one of the AO
284 registers to initiate the instantaneous simultaneous update of all
285 DAC outputs, which makes all AO channels update simultaneously.
286 This is useful for some control applications, I would imagine.
288 static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
289 struct comedi_insn *insn, unsigned int *data)
292 int chan = CR_CHAN(insn->chanspec);
294 for (i = 0; i < insn->n; i++) {
295 if (devpriv->simultaneous_xfer_mode)
297 /* read back shadow register */
298 data[i] = devpriv->ao_readback[chan];
305 * A convenient macro that defines init_module() and cleanup_module(),
308 static int __init driver_init_module(void)
310 return comedi_driver_register(&driver);
313 static void __exit driver_cleanup_module(void)
315 comedi_driver_unregister(&driver);
318 module_init(driver_init_module);
319 module_exit(driver_cleanup_module);
321 MODULE_AUTHOR("Comedi http://www.comedi.org");
322 MODULE_DESCRIPTION("Comedi low-level driver");
323 MODULE_LICENSE("GPL");