5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1998 David A. Schleef <ds@schleef.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.
25 Description: generic 8255 support
26 Devices: [standard] 8255 (8255)
29 Updated: Fri, 7 Jun 2002 12:56:45 -0700
31 The classic in digital I/O. The 8255 appears in Comedi as a single
32 digital I/O subdevice with 24 channels. The channel 0 corresponds
33 to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
34 7. Direction configuration is done in blocks, with channels 0-7,
35 8-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode
38 You should enable compilation this driver if you plan to use a board
39 that has an 8255 chip. For multifunction boards, the main driver will
40 configure the 8255 subdevice automatically.
42 This driver also works independently with ISA and PCI cards that
43 directly map the 8255 registers to I/O ports, including cards with
44 multiple 8255 chips. To configure the driver for such a card, the
45 option list should be a list of the I/O port bases for each of the
46 8255 chips. For example,
48 comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
50 Note that most PCI 8255 boards do NOT work with this driver, and
51 need a separate driver as a wrapper. For those that do work, the
52 I/O port base address can be found in the output of 'lspci -v'.
57 This file contains an exported subdevice for driving an 8255.
59 To use this subdevice as part of another driver, you need to
60 set up the subdevice in the attach function of the driver by
63 subdev_8255_init(device, subdevice, callback_function, arg)
65 device and subdevice are pointers to the device and subdevice
66 structures. callback_function will be called to provide the
67 low-level input/output to the device, i.e., actual register
68 access. callback_function will be called with the value of arg
69 as the last parameter. If the 8255 device is mapped as 4
70 consecutive I/O ports, you can use NULL for callback_function
71 and the I/O port base for arg, and an internal function will
72 handle the register access.
74 In addition, if the main driver handles interrupts, you can
75 enable commands on the subdevice by calling subdev_8255_init_irq()
76 instead. Then, when you get an interrupt that is likely to be
77 from the 8255, you should call subdev_8255_interrupt(), which
78 will copy the latched value to a Comedi buffer.
81 #include "../comedidev.h"
83 #include <linux/ioport.h>
84 #include <linux/slab.h>
91 #define CR_C_LO_IO 0x01
93 #define CR_B_MODE 0x04
94 #define CR_C_HI_IO 0x08
96 #define CR_A_MODE(a) ((a)<<5)
99 struct subdev_8255_struct
{
100 unsigned long cb_arg
;
101 int (*cb_func
) (int, int, int, unsigned long);
105 #define CALLBACK_ARG (((struct subdev_8255_struct *)s->private)->cb_arg)
106 #define CALLBACK_FUNC (((struct subdev_8255_struct *)s->private)->cb_func)
107 #define subdevpriv ((struct subdev_8255_struct *)s->private)
109 static int dev_8255_attach(struct comedi_device
*dev
,
110 struct comedi_devconfig
*it
);
111 static int dev_8255_detach(struct comedi_device
*dev
);
112 static struct comedi_driver driver_8255
= {
113 .driver_name
= "8255",
114 .module
= THIS_MODULE
,
115 .attach
= dev_8255_attach
,
116 .detach
= dev_8255_detach
,
119 COMEDI_INITCLEANUP(driver_8255
);
121 static void do_config(struct comedi_device
*dev
, struct comedi_subdevice
*s
);
123 void subdev_8255_interrupt(struct comedi_device
*dev
,
124 struct comedi_subdevice
*s
)
128 d
= CALLBACK_FUNC(0, _8255_DATA
, 0, CALLBACK_ARG
);
129 d
|= (CALLBACK_FUNC(0, _8255_DATA
+ 1, 0, CALLBACK_ARG
) << 8);
131 comedi_buf_put(s
->async
, d
);
132 s
->async
->events
|= COMEDI_CB_EOS
;
134 comedi_event(dev
, s
);
136 EXPORT_SYMBOL(subdev_8255_interrupt
);
138 static int subdev_8255_cb(int dir
, int port
, int data
, unsigned long arg
)
140 unsigned long iobase
= arg
;
143 outb(data
, iobase
+ port
);
146 return inb(iobase
+ port
);
150 static int subdev_8255_insn(struct comedi_device
*dev
,
151 struct comedi_subdevice
*s
,
152 struct comedi_insn
*insn
, unsigned int *data
)
155 s
->state
&= ~data
[0];
156 s
->state
|= (data
[0] & data
[1]);
159 CALLBACK_FUNC(1, _8255_DATA
, s
->state
& 0xff,
161 if (data
[0] & 0xff00)
162 CALLBACK_FUNC(1, _8255_DATA
+ 1, (s
->state
>> 8) & 0xff,
164 if (data
[0] & 0xff0000)
165 CALLBACK_FUNC(1, _8255_DATA
+ 2,
166 (s
->state
>> 16) & 0xff, CALLBACK_ARG
);
169 data
[1] = CALLBACK_FUNC(0, _8255_DATA
, 0, CALLBACK_ARG
);
170 data
[1] |= (CALLBACK_FUNC(0, _8255_DATA
+ 1, 0, CALLBACK_ARG
) << 8);
171 data
[1] |= (CALLBACK_FUNC(0, _8255_DATA
+ 2, 0, CALLBACK_ARG
) << 16);
176 static int subdev_8255_insn_config(struct comedi_device
*dev
,
177 struct comedi_subdevice
*s
,
178 struct comedi_insn
*insn
, unsigned int *data
)
183 mask
= 1 << CR_CHAN(insn
->chanspec
);
186 else if (mask
& 0x00ff00)
188 else if (mask
& 0x0f0000)
194 case INSN_CONFIG_DIO_INPUT
:
197 case INSN_CONFIG_DIO_OUTPUT
:
200 case INSN_CONFIG_DIO_QUERY
:
201 data
[1] = (s
->io_bits
& bits
) ? COMEDI_OUTPUT
: COMEDI_INPUT
;
213 static void do_config(struct comedi_device
*dev
, struct comedi_subdevice
*s
)
218 /* 1 in io_bits indicates output, 1 in config indicates input */
219 if (!(s
->io_bits
& 0x0000ff))
221 if (!(s
->io_bits
& 0x00ff00))
223 if (!(s
->io_bits
& 0x0f0000))
224 config
|= CR_C_LO_IO
;
225 if (!(s
->io_bits
& 0xf00000))
226 config
|= CR_C_HI_IO
;
227 CALLBACK_FUNC(1, _8255_CR
, config
, CALLBACK_ARG
);
230 static int subdev_8255_cmdtest(struct comedi_device
*dev
,
231 struct comedi_subdevice
*s
,
232 struct comedi_cmd
*cmd
)
239 tmp
= cmd
->start_src
;
240 cmd
->start_src
&= TRIG_NOW
;
241 if (!cmd
->start_src
|| tmp
!= cmd
->start_src
)
244 tmp
= cmd
->scan_begin_src
;
245 cmd
->scan_begin_src
&= TRIG_EXT
;
246 if (!cmd
->scan_begin_src
|| tmp
!= cmd
->scan_begin_src
)
249 tmp
= cmd
->convert_src
;
250 cmd
->convert_src
&= TRIG_FOLLOW
;
251 if (!cmd
->convert_src
|| tmp
!= cmd
->convert_src
)
254 tmp
= cmd
->scan_end_src
;
255 cmd
->scan_end_src
&= TRIG_COUNT
;
256 if (!cmd
->scan_end_src
|| tmp
!= cmd
->scan_end_src
)
260 cmd
->stop_src
&= TRIG_NONE
;
261 if (!cmd
->stop_src
|| tmp
!= cmd
->stop_src
)
274 if (cmd
->start_arg
!= 0) {
278 if (cmd
->scan_begin_arg
!= 0) {
279 cmd
->scan_begin_arg
= 0;
282 if (cmd
->convert_arg
!= 0) {
283 cmd
->convert_arg
= 0;
286 if (cmd
->scan_end_arg
!= 1) {
287 cmd
->scan_end_arg
= 1;
290 if (cmd
->stop_arg
!= 0) {
306 static int subdev_8255_cmd(struct comedi_device
*dev
,
307 struct comedi_subdevice
*s
)
314 static int subdev_8255_cancel(struct comedi_device
*dev
,
315 struct comedi_subdevice
*s
)
322 int subdev_8255_init(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
323 int (*cb
) (int, int, int, unsigned long),
326 s
->type
= COMEDI_SUBD_DIO
;
327 s
->subdev_flags
= SDF_READABLE
| SDF_WRITABLE
;
329 s
->range_table
= &range_digital
;
332 s
->private = kmalloc(sizeof(struct subdev_8255_struct
), GFP_KERNEL
);
338 CALLBACK_FUNC
= subdev_8255_cb
;
341 s
->insn_bits
= subdev_8255_insn
;
342 s
->insn_config
= subdev_8255_insn_config
;
350 EXPORT_SYMBOL(subdev_8255_init
);
352 int subdev_8255_init_irq(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
353 int (*cb
) (int, int, int, unsigned long),
358 ret
= subdev_8255_init(dev
, s
, cb
, arg
);
362 s
->do_cmdtest
= subdev_8255_cmdtest
;
363 s
->do_cmd
= subdev_8255_cmd
;
364 s
->cancel
= subdev_8255_cancel
;
366 subdevpriv
->have_irq
= 1;
370 EXPORT_SYMBOL(subdev_8255_init_irq
);
372 void subdev_8255_cleanup(struct comedi_device
*dev
, struct comedi_subdevice
*s
)
375 /* this test does nothing, so comment it out
376 * if (subdevpriv->have_irq) {
383 EXPORT_SYMBOL(subdev_8255_cleanup
);
387 Start of the 8255 standalone device
391 static int dev_8255_attach(struct comedi_device
*dev
,
392 struct comedi_devconfig
*it
)
395 unsigned long iobase
;
398 printk("comedi%d: 8255:", dev
->minor
);
400 dev
->board_name
= "8255";
402 for (i
= 0; i
< COMEDI_NDEVCONFOPTS
; i
++) {
403 iobase
= it
->options
[i
];
408 printk(" no devices specified\n");
412 ret
= alloc_subdevices(dev
, i
);
416 for (i
= 0; i
< dev
->n_subdevices
; i
++) {
417 iobase
= it
->options
[i
];
419 printk(" 0x%04lx", iobase
);
420 if (!request_region(iobase
, _8255_SIZE
, "8255")) {
421 printk(" (I/O port conflict)");
423 dev
->subdevices
[i
].type
= COMEDI_SUBD_UNUSED
;
425 subdev_8255_init(dev
, dev
->subdevices
+ i
, NULL
,
435 static int dev_8255_detach(struct comedi_device
*dev
)
438 unsigned long iobase
;
439 struct comedi_subdevice
*s
;
441 printk("comedi%d: 8255: remove\n", dev
->minor
);
443 for (i
= 0; i
< dev
->n_subdevices
; i
++) {
444 s
= dev
->subdevices
+ i
;
445 if (s
->type
!= COMEDI_SUBD_UNUSED
) {
446 iobase
= CALLBACK_ARG
;
447 release_region(iobase
, _8255_SIZE
);
449 subdev_8255_cleanup(dev
, s
);