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;
101 #define devpriv ((struct pcmda12_private *)(dev->private))
104 * The struct comedi_driver structure tells the Comedi core module
105 * which functions to call to configure/deconfigure (attach/detach)
106 * the board, and also about the kernel module that contains
109 static int pcmda12_attach(struct comedi_device *dev, 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, struct comedi_devconfig *it)
155 struct comedi_subdevice *s;
156 unsigned long iobase;
158 iobase = it->options[0];
159 printk("comedi%d: %s: io: %lx %s ", dev->minor, driver.driver_name,
160 iobase, it->options[1] ? "simultaneous xfer mode enabled" : "");
162 if (!request_region(iobase, IOSIZE, driver.driver_name)) {
163 printk("I/O port conflict\n");
166 dev->iobase = iobase;
169 * Initialize dev->board_name. Note that we can use the "thisboard"
170 * macro now, since we just initialized it in the last line.
172 dev->board_name = thisboard->name;
175 * Allocate the private structure area. alloc_private() is a
176 * convenient macro defined in comedidev.h.
178 if (alloc_private(dev, sizeof(struct pcmda12_private)) < 0) {
179 printk("cannot allocate private data structure\n");
183 devpriv->simultaneous_xfer_mode = it->options[1];
186 * Allocate the subdevice structures. alloc_subdevice() is a
187 * convenient macro defined in comedidev.h.
189 * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the
190 * 96-channel version of the board.
192 if (alloc_subdevices(dev, 1) < 0) {
193 printk("cannot allocate subdevice data structures\n");
199 s->maxdata = (0x1 << BITS) - 1;
200 s->range_table = &pcmda12_ranges;
201 s->type = COMEDI_SUBD_AO;
202 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
204 s->insn_write = &ao_winsn;
205 s->insn_read = &ao_rinsn;
207 zero_chans(dev); /* clear out all the registers, basically */
209 printk("attached\n");
215 * _detach is called to deconfigure a device. It should deallocate
217 * This function is also called when _attach() fails, so it should be
218 * careful not to release resources that were not necessarily
219 * allocated by _attach(). dev->private and dev->subdevices are
220 * deallocated automatically by the core.
222 static int pcmda12_detach(struct comedi_device *dev)
224 printk("comedi%d: %s: remove\n", dev->minor, driver.driver_name);
226 release_region(dev->iobase, IOSIZE);
230 static void zero_chans(struct comedi_device *dev)
232 ASIC chip to defaults */
234 for (i = 0; i < CHANS; ++i) {
235 /* /\* do this as one instruction?? *\/ */
236 /* outw(0, LSB_PORT(chan)); */
237 outb(0, LSB_PORT(i));
238 outb(0, MSB_PORT(i));
240 inb(LSB_PORT(0)); /* update chans. */
243 static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
244 struct comedi_insn *insn, unsigned int *data)
247 int chan = CR_CHAN(insn->chanspec);
249 /* Writing a list of values to an AO channel is probably not
250 * very useful, but that's how the interface is defined. */
251 for (i = 0; i < insn->n; ++i) {
253 /* /\* do this as one instruction?? *\/ */
254 /* outw(data[i], LSB_PORT(chan)); */
256 /* Need to do this as two instructions due to 8-bit bus?? */
257 /* first, load the low byte */
258 outb(LSB(data[i]), LSB_PORT(chan));
259 /* next, write the high byte */
260 outb(MSB(data[i]), MSB_PORT(chan));
262 /* save shadow register */
263 devpriv->ao_readback[chan] = data[i];
265 if (!devpriv->simultaneous_xfer_mode)
269 /* return the number of samples written */
273 /* AO subdevices should have a read insn as well as a write insn.
275 Usually this means copying a value stored in devpriv->ao_readback.
276 However, since this driver supports simultaneous xfer then sometimes
277 this function actually accomplishes work.
279 Simultaneaous xfer mode is accomplished by loading ALL the values
280 you want for AO in all the channels, then READing off one of the AO
281 registers to initiate the instantaneous simultaneous update of all
282 DAC outputs, which makes all AO channels update simultaneously.
283 This is useful for some control applications, I would imagine.
285 static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
286 struct comedi_insn *insn, unsigned int *data)
289 int chan = CR_CHAN(insn->chanspec);
291 for (i = 0; i < insn->n; i++) {
292 if (devpriv->simultaneous_xfer_mode)
294 /* read back shadow register */
295 data[i] = devpriv->ao_readback[chan];
302 * A convenient macro that defines init_module() and cleanup_module(),
305 COMEDI_INITCLEANUP(driver);