1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * comedi_parport.c
4 * Comedi driver for standard parallel port
5 *
6 * For more information see:
7 * http://retired.beyondlogic.org/spp/parallel.htm
8 *
9 * COMEDI - Linux Control and Measurement Device Interface
10 * Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
11 */
12
13 /*
14 * Driver: comedi_parport
15 * Description: Standard PC parallel port
16 * Author: ds
17 * Status: works in immediate mode
18 * Devices: [standard] parallel port (comedi_parport)
19 * Updated: Tue, 30 Apr 2002 21:11:45 -0700
20 *
21 * A cheap and easy way to get a few more digital I/O lines. Steal
22 * additional parallel ports from old computers or your neighbors'
23 * computers.
24 *
25 * Option list:
26 * 0: I/O port base for the parallel port.
27 * 1: IRQ (optional)
28 *
29 * Parallel Port Lines:
30 *
31 * pin subdev chan type name
32 * ----- ------ ---- ---- --------------
33 * 1 2 0 DO strobe
34 * 2 0 0 DIO data 0
35 * 3 0 1 DIO data 1
36 * 4 0 2 DIO data 2
37 * 5 0 3 DIO data 3
38 * 6 0 4 DIO data 4
39 * 7 0 5 DIO data 5
40 * 8 0 6 DIO data 6
41 * 9 0 7 DIO data 7
42 * 10 1 3 DI ack
43 * 11 1 4 DI busy
44 * 12 1 2 DI paper out
45 * 13 1 1 DI select in
46 * 14 2 1 DO auto LF
47 * 15 1 0 DI error
48 * 16 2 2 DO init
49 * 17 2 3 DO select printer
50 * 18-25 ground
51 *
52 * When an IRQ is configured subdevice 3 pretends to be a digital
53 * input subdevice, but it always returns 0 when read. However, if
54 * you run a command with scan_begin_src=TRIG_EXT, it uses pin 10
55 * as a external trigger, which can be used to wake up tasks.
56 */
57
58 #include <linux/module.h>
59 #include <linux/interrupt.h>
60
61 #include "../comedidev.h"
62
63 /*
64 * Register map
65 */
66 #define PARPORT_DATA_REG 0x00
67 #define PARPORT_STATUS_REG 0x01
68 #define PARPORT_CTRL_REG 0x02
69 #define PARPORT_CTRL_IRQ_ENA BIT(4)
70 #define PARPORT_CTRL_BIDIR_ENA BIT(5)
71
parport_data_reg_insn_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)72 static int parport_data_reg_insn_bits(struct comedi_device *dev,
73 struct comedi_subdevice *s,
74 struct comedi_insn *insn,
75 unsigned int *data)
76 {
77 if (comedi_dio_update_state(s, data))
78 outb(s->state, dev->iobase + PARPORT_DATA_REG);
79
80 data[1] = inb(dev->iobase + PARPORT_DATA_REG);
81
82 return insn->n;
83 }
84
parport_data_reg_insn_config(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)85 static int parport_data_reg_insn_config(struct comedi_device *dev,
86 struct comedi_subdevice *s,
87 struct comedi_insn *insn,
88 unsigned int *data)
89 {
90 unsigned int ctrl;
91 int ret;
92
93 ret = comedi_dio_insn_config(dev, s, insn, data, 0xff);
94 if (ret)
95 return ret;
96
97 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
98 if (s->io_bits)
99 ctrl &= ~PARPORT_CTRL_BIDIR_ENA;
100 else
101 ctrl |= PARPORT_CTRL_BIDIR_ENA;
102 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
103
104 return insn->n;
105 }
106
parport_status_reg_insn_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)107 static int parport_status_reg_insn_bits(struct comedi_device *dev,
108 struct comedi_subdevice *s,
109 struct comedi_insn *insn,
110 unsigned int *data)
111 {
112 data[1] = inb(dev->iobase + PARPORT_STATUS_REG) >> 3;
113
114 return insn->n;
115 }
116
parport_ctrl_reg_insn_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)117 static int parport_ctrl_reg_insn_bits(struct comedi_device *dev,
118 struct comedi_subdevice *s,
119 struct comedi_insn *insn,
120 unsigned int *data)
121 {
122 unsigned int ctrl;
123
124 if (comedi_dio_update_state(s, data)) {
125 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
126 ctrl &= (PARPORT_CTRL_IRQ_ENA | PARPORT_CTRL_BIDIR_ENA);
127 ctrl |= s->state;
128 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
129 }
130
131 data[1] = s->state;
132
133 return insn->n;
134 }
135
parport_intr_insn_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)136 static int parport_intr_insn_bits(struct comedi_device *dev,
137 struct comedi_subdevice *s,
138 struct comedi_insn *insn,
139 unsigned int *data)
140 {
141 data[1] = 0;
142 return insn->n;
143 }
144
parport_intr_cmdtest(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_cmd * cmd)145 static int parport_intr_cmdtest(struct comedi_device *dev,
146 struct comedi_subdevice *s,
147 struct comedi_cmd *cmd)
148 {
149 int err = 0;
150
151 /* Step 1 : check if triggers are trivially valid */
152
153 err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
154 err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
155 err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
156 err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
157 err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_NONE);
158
159 if (err)
160 return 1;
161
162 /* Step 2a : make sure trigger sources are unique */
163 /* Step 2b : and mutually compatible */
164
165 /* Step 3: check if arguments are trivially valid */
166
167 err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
168 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
169 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
170 err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
171 cmd->chanlist_len);
172 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
173
174 if (err)
175 return 3;
176
177 /* Step 4: fix up any arguments */
178
179 /* Step 5: check channel list if it exists */
180
181 return 0;
182 }
183
parport_intr_cmd(struct comedi_device * dev,struct comedi_subdevice * s)184 static int parport_intr_cmd(struct comedi_device *dev,
185 struct comedi_subdevice *s)
186 {
187 unsigned int ctrl;
188
189 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
190 ctrl |= PARPORT_CTRL_IRQ_ENA;
191 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
192
193 return 0;
194 }
195
parport_intr_cancel(struct comedi_device * dev,struct comedi_subdevice * s)196 static int parport_intr_cancel(struct comedi_device *dev,
197 struct comedi_subdevice *s)
198 {
199 unsigned int ctrl;
200
201 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
202 ctrl &= ~PARPORT_CTRL_IRQ_ENA;
203 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
204
205 return 0;
206 }
207
parport_interrupt(int irq,void * d)208 static irqreturn_t parport_interrupt(int irq, void *d)
209 {
210 struct comedi_device *dev = d;
211 struct comedi_subdevice *s = dev->read_subdev;
212 unsigned int ctrl;
213 unsigned short val = 0;
214
215 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
216 if (!(ctrl & PARPORT_CTRL_IRQ_ENA))
217 return IRQ_NONE;
218
219 comedi_buf_write_samples(s, &val, 1);
220 comedi_handle_events(dev, s);
221
222 return IRQ_HANDLED;
223 }
224
parport_attach(struct comedi_device * dev,struct comedi_devconfig * it)225 static int parport_attach(struct comedi_device *dev,
226 struct comedi_devconfig *it)
227 {
228 struct comedi_subdevice *s;
229 int ret;
230
231 ret = comedi_request_region(dev, it->options[0], 0x03);
232 if (ret)
233 return ret;
234
235 if (it->options[1]) {
236 ret = request_irq(it->options[1], parport_interrupt, 0,
237 dev->board_name, dev);
238 if (ret == 0)
239 dev->irq = it->options[1];
240 }
241
242 ret = comedi_alloc_subdevices(dev, dev->irq ? 4 : 3);
243 if (ret)
244 return ret;
245
246 /* Digial I/O subdevice - Parallel port DATA register */
247 s = &dev->subdevices[0];
248 s->type = COMEDI_SUBD_DIO;
249 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
250 s->n_chan = 8;
251 s->maxdata = 1;
252 s->range_table = &range_digital;
253 s->insn_bits = parport_data_reg_insn_bits;
254 s->insn_config = parport_data_reg_insn_config;
255
256 /* Digial Input subdevice - Parallel port STATUS register */
257 s = &dev->subdevices[1];
258 s->type = COMEDI_SUBD_DI;
259 s->subdev_flags = SDF_READABLE;
260 s->n_chan = 5;
261 s->maxdata = 1;
262 s->range_table = &range_digital;
263 s->insn_bits = parport_status_reg_insn_bits;
264
265 /* Digial Output subdevice - Parallel port CONTROL register */
266 s = &dev->subdevices[2];
267 s->type = COMEDI_SUBD_DO;
268 s->subdev_flags = SDF_WRITABLE;
269 s->n_chan = 4;
270 s->maxdata = 1;
271 s->range_table = &range_digital;
272 s->insn_bits = parport_ctrl_reg_insn_bits;
273
274 if (dev->irq) {
275 /* Digial Input subdevice - Interrupt support */
276 s = &dev->subdevices[3];
277 dev->read_subdev = s;
278 s->type = COMEDI_SUBD_DI;
279 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
280 s->n_chan = 1;
281 s->maxdata = 1;
282 s->range_table = &range_digital;
283 s->insn_bits = parport_intr_insn_bits;
284 s->len_chanlist = 1;
285 s->do_cmdtest = parport_intr_cmdtest;
286 s->do_cmd = parport_intr_cmd;
287 s->cancel = parport_intr_cancel;
288 }
289
290 outb(0, dev->iobase + PARPORT_DATA_REG);
291 outb(0, dev->iobase + PARPORT_CTRL_REG);
292
293 return 0;
294 }
295
296 static struct comedi_driver parport_driver = {
297 .driver_name = "comedi_parport",
298 .module = THIS_MODULE,
299 .attach = parport_attach,
300 .detach = comedi_legacy_detach,
301 };
302 module_comedi_driver(parport_driver);
303
304 MODULE_AUTHOR("Comedi https://www.comedi.org");
305 MODULE_DESCRIPTION("Comedi: Standard parallel port driver");
306 MODULE_LICENSE("GPL");
307