1 // SPDX-License-Identifier: GPL-2.0+
4 * Comedi driver for standard parallel port
6 * For more information see:
7 * http://retired.beyondlogic.org/spp/parallel.htm
9 * COMEDI - Linux Control and Measurement Device Interface
10 * Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
14 * Driver: comedi_parport
15 * Description: Standard PC parallel port
17 * Status: works in immediate mode
18 * Devices: [standard] parallel port (comedi_parport)
19 * Updated: Tue, 30 Apr 2002 21:11:45 -0700
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'
26 * 0: I/O port base for the parallel port.
29 * Parallel Port Lines:
31 * pin subdev chan type name
32 * ----- ------ ---- ---- --------------
49 * 17 2 3 DO select printer
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.
58 #include <linux/module.h>
59 #include <linux/interrupt.h>
60 #include <linux/comedi/comedidev.h>
65 #define PARPORT_DATA_REG 0x00
66 #define PARPORT_STATUS_REG 0x01
67 #define PARPORT_CTRL_REG 0x02
68 #define PARPORT_CTRL_IRQ_ENA BIT(4)
69 #define PARPORT_CTRL_BIDIR_ENA BIT(5)
71 static int parport_data_reg_insn_bits(struct comedi_device *dev,
72 struct comedi_subdevice *s,
73 struct comedi_insn *insn,
76 if (comedi_dio_update_state(s, data))
77 outb(s->state, dev->iobase + PARPORT_DATA_REG);
79 data[1] = inb(dev->iobase + PARPORT_DATA_REG);
84 static int parport_data_reg_insn_config(struct comedi_device *dev,
85 struct comedi_subdevice *s,
86 struct comedi_insn *insn,
92 ret = comedi_dio_insn_config(dev, s, insn, data, 0xff);
96 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
98 ctrl &= ~PARPORT_CTRL_BIDIR_ENA;
100 ctrl |= PARPORT_CTRL_BIDIR_ENA;
101 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
106 static int parport_status_reg_insn_bits(struct comedi_device *dev,
107 struct comedi_subdevice *s,
108 struct comedi_insn *insn,
111 data[1] = inb(dev->iobase + PARPORT_STATUS_REG) >> 3;
116 static int parport_ctrl_reg_insn_bits(struct comedi_device *dev,
117 struct comedi_subdevice *s,
118 struct comedi_insn *insn,
123 if (comedi_dio_update_state(s, data)) {
124 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
125 ctrl &= (PARPORT_CTRL_IRQ_ENA | PARPORT_CTRL_BIDIR_ENA);
127 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
135 static int parport_intr_insn_bits(struct comedi_device *dev,
136 struct comedi_subdevice *s,
137 struct comedi_insn *insn,
144 static int parport_intr_cmdtest(struct comedi_device *dev,
145 struct comedi_subdevice *s,
146 struct comedi_cmd *cmd)
150 /* Step 1 : check if triggers are trivially valid */
152 err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
153 err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
154 err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
155 err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
156 err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_NONE);
161 /* Step 2a : make sure trigger sources are unique */
162 /* Step 2b : and mutually compatible */
164 /* Step 3: check if arguments are trivially valid */
166 err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
167 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
168 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
169 err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
171 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
176 /* Step 4: fix up any arguments */
178 /* Step 5: check channel list if it exists */
183 static int parport_intr_cmd(struct comedi_device *dev,
184 struct comedi_subdevice *s)
188 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
189 ctrl |= PARPORT_CTRL_IRQ_ENA;
190 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
195 static int parport_intr_cancel(struct comedi_device *dev,
196 struct comedi_subdevice *s)
200 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
201 ctrl &= ~PARPORT_CTRL_IRQ_ENA;
202 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
207 static irqreturn_t parport_interrupt(int irq, void *d)
209 struct comedi_device *dev = d;
210 struct comedi_subdevice *s = dev->read_subdev;
212 unsigned short val = 0;
214 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
215 if (!(ctrl & PARPORT_CTRL_IRQ_ENA))
218 comedi_buf_write_samples(s, &val, 1);
219 comedi_handle_events(dev, s);
224 static int parport_attach(struct comedi_device *dev,
225 struct comedi_devconfig *it)
227 struct comedi_subdevice *s;
230 ret = comedi_request_region(dev, it->options[0], 0x03);
234 if (it->options[1]) {
235 ret = request_irq(it->options[1], parport_interrupt, 0,
236 dev->board_name, dev);
238 dev->irq = it->options[1];
241 ret = comedi_alloc_subdevices(dev, dev->irq ? 4 : 3);
245 /* Digial I/O subdevice - Parallel port DATA register */
246 s = &dev->subdevices[0];
247 s->type = COMEDI_SUBD_DIO;
248 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
251 s->range_table = &range_digital;
252 s->insn_bits = parport_data_reg_insn_bits;
253 s->insn_config = parport_data_reg_insn_config;
255 /* Digial Input subdevice - Parallel port STATUS register */
256 s = &dev->subdevices[1];
257 s->type = COMEDI_SUBD_DI;
258 s->subdev_flags = SDF_READABLE;
261 s->range_table = &range_digital;
262 s->insn_bits = parport_status_reg_insn_bits;
264 /* Digial Output subdevice - Parallel port CONTROL register */
265 s = &dev->subdevices[2];
266 s->type = COMEDI_SUBD_DO;
267 s->subdev_flags = SDF_WRITABLE;
270 s->range_table = &range_digital;
271 s->insn_bits = parport_ctrl_reg_insn_bits;
274 /* Digial Input subdevice - Interrupt support */
275 s = &dev->subdevices[3];
276 dev->read_subdev = s;
277 s->type = COMEDI_SUBD_DI;
278 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
281 s->range_table = &range_digital;
282 s->insn_bits = parport_intr_insn_bits;
284 s->do_cmdtest = parport_intr_cmdtest;
285 s->do_cmd = parport_intr_cmd;
286 s->cancel = parport_intr_cancel;
289 outb(0, dev->iobase + PARPORT_DATA_REG);
290 outb(0, dev->iobase + PARPORT_CTRL_REG);
295 static struct comedi_driver parport_driver = {
296 .driver_name = "comedi_parport",
297 .module = THIS_MODULE,
298 .attach = parport_attach,
299 .detach = comedi_legacy_detach,
301 module_comedi_driver(parport_driver);
303 MODULE_AUTHOR("Comedi https://www.comedi.org");
304 MODULE_DESCRIPTION("Comedi: Standard parallel port driver");
305 MODULE_LICENSE("GPL");