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 struct pcmda12_private
{
85 unsigned int ao_readback
[CHANS
];
86 int simultaneous_xfer_mode
;
89 #define devpriv ((struct pcmda12_private *)(dev->private))
91 static void zero_chans(struct comedi_device
*dev
)
93 ASIC chip to defaults */
95 for (i
= 0; i
< CHANS
; ++i
) {
96 /* /\* do this as one instruction?? *\/ */
97 /* outw(0, LSB_PORT(chan)); */
101 inb(LSB_PORT(0)); /* update chans. */
104 static int ao_winsn(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
105 struct comedi_insn
*insn
, unsigned int *data
)
108 int chan
= CR_CHAN(insn
->chanspec
);
110 /* Writing a list of values to an AO channel is probably not
111 * very useful, but that's how the interface is defined. */
112 for (i
= 0; i
< insn
->n
; ++i
) {
114 /* /\* do this as one instruction?? *\/ */
115 /* outw(data[i], LSB_PORT(chan)); */
117 /* Need to do this as two instructions due to 8-bit bus?? */
118 /* first, load the low byte */
119 outb(LSB(data
[i
]), LSB_PORT(chan
));
120 /* next, write the high byte */
121 outb(MSB(data
[i
]), MSB_PORT(chan
));
123 /* save shadow register */
124 devpriv
->ao_readback
[chan
] = data
[i
];
126 if (!devpriv
->simultaneous_xfer_mode
)
130 /* return the number of samples written */
134 /* AO subdevices should have a read insn as well as a write insn.
136 Usually this means copying a value stored in devpriv->ao_readback.
137 However, since this driver supports simultaneous xfer then sometimes
138 this function actually accomplishes work.
140 Simultaneaous xfer mode is accomplished by loading ALL the values
141 you want for AO in all the channels, then READing off one of the AO
142 registers to initiate the instantaneous simultaneous update of all
143 DAC outputs, which makes all AO channels update simultaneously.
144 This is useful for some control applications, I would imagine.
146 static int ao_rinsn(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
147 struct comedi_insn
*insn
, unsigned int *data
)
150 int chan
= CR_CHAN(insn
->chanspec
);
152 for (i
= 0; i
< insn
->n
; i
++) {
153 if (devpriv
->simultaneous_xfer_mode
)
155 /* read back shadow register */
156 data
[i
] = devpriv
->ao_readback
[chan
];
162 static int pcmda12_attach(struct comedi_device
*dev
,
163 struct comedi_devconfig
*it
)
165 const struct pcmda12_board
*board
= comedi_board(dev
);
166 struct comedi_subdevice
*s
;
167 unsigned long iobase
;
170 iobase
= it
->options
[0];
172 "comedi%d: %s: io: %lx %s ", dev
->minor
, dev
->driver
->driver_name
,
173 iobase
, it
->options
[1] ? "simultaneous xfer mode enabled" : "");
175 if (!request_region(iobase
, IOSIZE
, dev
->driver
->driver_name
)) {
176 printk("I/O port conflict\n");
179 dev
->iobase
= iobase
;
181 dev
->board_name
= board
->name
;
184 * Allocate the private structure area. alloc_private() is a
185 * convenient macro defined in comedidev.h.
187 if (alloc_private(dev
, sizeof(struct pcmda12_private
)) < 0) {
188 printk(KERN_ERR
"cannot allocate private data structure\n");
192 devpriv
->simultaneous_xfer_mode
= it
->options
[1];
194 ret
= comedi_alloc_subdevices(dev
, 1);
198 s
= &dev
->subdevices
[0];
200 s
->maxdata
= (0x1 << BITS
) - 1;
201 s
->range_table
= &pcmda12_ranges
;
202 s
->type
= COMEDI_SUBD_AO
;
203 s
->subdev_flags
= SDF_READABLE
| SDF_WRITABLE
;
205 s
->insn_write
= &ao_winsn
;
206 s
->insn_read
= &ao_rinsn
;
208 zero_chans(dev
); /* clear out all the registers, basically */
210 printk(KERN_INFO
"attached\n");
215 static void pcmda12_detach(struct comedi_device
*dev
)
218 release_region(dev
->iobase
, IOSIZE
);
221 static const struct pcmda12_board pcmda12_boards
[] = {
227 static struct comedi_driver pcmda12_driver
= {
228 .driver_name
= "pcmda12",
229 .module
= THIS_MODULE
,
230 .attach
= pcmda12_attach
,
231 .detach
= pcmda12_detach
,
232 .board_name
= &pcmda12_boards
[0].name
,
233 .offset
= sizeof(struct pcmda12_board
),
234 .num_names
= ARRAY_SIZE(pcmda12_boards
),
236 module_comedi_driver(pcmda12_driver
);
238 MODULE_AUTHOR("Comedi http://www.comedi.org");
239 MODULE_DESCRIPTION("Comedi low-level driver");
240 MODULE_LICENSE("GPL");