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>
61 #include "../comedidev.h"
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)
72 static int parport_data_reg_insn_bits(struct comedi_device *dev,
73 struct comedi_subdevice *s,
74 struct comedi_insn *insn,
77 if (comedi_dio_update_state(s, data))
78 outb(s->state, dev->iobase + PARPORT_DATA_REG);
80 data[1] = inb(dev->iobase + PARPORT_DATA_REG);
85 static int parport_data_reg_insn_config(struct comedi_device *dev,
86 struct comedi_subdevice *s,
87 struct comedi_insn *insn,
93 ret = comedi_dio_insn_config(dev, s, insn, data, 0xff);
97 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
99 ctrl &= ~PARPORT_CTRL_BIDIR_ENA;
101 ctrl |= PARPORT_CTRL_BIDIR_ENA;
102 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
107 static int parport_status_reg_insn_bits(struct comedi_device *dev,
108 struct comedi_subdevice *s,
109 struct comedi_insn *insn,
112 data[1] = inb(dev->iobase + PARPORT_STATUS_REG) >> 3;
117 static int parport_ctrl_reg_insn_bits(struct comedi_device *dev,
118 struct comedi_subdevice *s,
119 struct comedi_insn *insn,
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);
128 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
136 static int parport_intr_insn_bits(struct comedi_device *dev,
137 struct comedi_subdevice *s,
138 struct comedi_insn *insn,
145 static int parport_intr_cmdtest(struct comedi_device *dev,
146 struct comedi_subdevice *s,
147 struct comedi_cmd *cmd)
151 /* Step 1 : check if triggers are trivially valid */
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);
162 /* Step 2a : make sure trigger sources are unique */
163 /* Step 2b : and mutually compatible */
165 /* Step 3: check if arguments are trivially valid */
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,
172 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
177 /* Step 4: fix up any arguments */
179 /* Step 5: check channel list if it exists */
184 static int parport_intr_cmd(struct comedi_device *dev,
185 struct comedi_subdevice *s)
189 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
190 ctrl |= PARPORT_CTRL_IRQ_ENA;
191 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
196 static int parport_intr_cancel(struct comedi_device *dev,
197 struct comedi_subdevice *s)
201 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
202 ctrl &= ~PARPORT_CTRL_IRQ_ENA;
203 outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
208 static irqreturn_t parport_interrupt(int irq, void *d)
210 struct comedi_device *dev = d;
211 struct comedi_subdevice *s = dev->read_subdev;
213 unsigned short val = 0;
215 ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
216 if (!(ctrl & PARPORT_CTRL_IRQ_ENA))
219 comedi_buf_write_samples(s, &val, 1);
220 comedi_handle_events(dev, s);
225 static int parport_attach(struct comedi_device *dev,
226 struct comedi_devconfig *it)
228 struct comedi_subdevice *s;
231 ret = comedi_request_region(dev, it->options[0], 0x03);
235 if (it->options[1]) {
236 ret = request_irq(it->options[1], parport_interrupt, 0,
237 dev->board_name, dev);
239 dev->irq = it->options[1];
242 ret = comedi_alloc_subdevices(dev, dev->irq ? 4 : 3);
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;
252 s->range_table = &range_digital;
253 s->insn_bits = parport_data_reg_insn_bits;
254 s->insn_config = parport_data_reg_insn_config;
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;
262 s->range_table = &range_digital;
263 s->insn_bits = parport_status_reg_insn_bits;
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;
271 s->range_table = &range_digital;
272 s->insn_bits = parport_ctrl_reg_insn_bits;
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;
282 s->range_table = &range_digital;
283 s->insn_bits = parport_intr_insn_bits;
285 s->do_cmdtest = parport_intr_cmdtest;
286 s->do_cmd = parport_intr_cmd;
287 s->cancel = parport_intr_cancel;
290 outb(0, dev->iobase + PARPORT_DATA_REG);
291 outb(0, dev->iobase + PARPORT_CTRL_REG);
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,
302 module_comedi_driver(parport_driver);
304 MODULE_AUTHOR("Comedi https://www.comedi.org");
305 MODULE_DESCRIPTION("Comedi: Standard parallel port driver");
306 MODULE_LICENSE("GPL");