Staging: comedi: add comedi_parport driver

This adds the comedi_parport driver to the kernel tree

From: David Schleef <ds@schleef.org>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/Makefile

@@ -5,6 +5,7 @@
 obj-$(CONFIG_COMEDI)			+= comedi_fc.o
 obj-$(CONFIG_COMEDI)			+= comedi_bond.o
 obj-$(CONFIG_COMEDI)			+= comedi_test.o
+obj-$(CONFIG_COMEDI)			+= comedi_parport.o
 
 # Comedi PCI drivers
 obj-$(CONFIG_COMEDI_PCI_DRIVERS)	+= mite.o

drivers/staging/comedi/drivers/comedi_parport.c

+/*
+    comedi/drivers/comedi_parport.c
+    hardware driver for standard parallel port
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+/*
+Driver: comedi_parport
+Description: Standard PC parallel port
+Author: ds
+Status: works in immediate mode
+Devices: [standard] parallel port (comedi_parport)
+Updated: Tue, 30 Apr 2002 21:11:45 -0700
+
+A cheap and easy way to get a few more digital I/O lines.  Steal
+additional parallel ports from old computers or your neighbors'
+computers.
+
+Option list:
+ 0: I/O port base for the parallel port.
+ 1: IRQ
+
+Parallel Port Lines:
+
+pin     subdev  chan    aka
+---     ------  ----    ---
+1       2       0       strobe
+2       0       0       data 0
+3       0       1       data 1
+4       0       2       data 2
+5       0       3       data 3
+6       0       4       data 4
+7       0       5       data 5
+8       0       6       data 6
+9       0       7       data 7
+10      1       3       acknowledge
+11      1       4       busy
+12      1       2       output
+13      1       1       printer selected
+14      2       1       auto LF
+15      1       0       error
+16      2       2       init
+17      2       3       select printer
+18-25   ground
+
+Notes:
+
+Subdevices 0 is digital I/O, subdevice 1 is digital input, and
+subdevice 2 is digital output.  Unlike other Comedi devices,
+subdevice 0 defaults to output.
+
+Pins 13 and 14 are inverted once by Comedi and once by the
+hardware, thus cancelling the effect.
+
+Pin 1 is a strobe, thus acts like one.  There's no way in software
+to change this, at least on a standard parallel port.
+
+Subdevice 3 pretends to be a digital input subdevice, but it always
+returns 0 when read.  However, if you run a command with
+scan_begin_src=TRIG_EXT, it uses pin 10 as a external triggering
+pin, which can be used to wake up tasks.
+*/
+/*
+   see http://www.beyondlogic.org/ for information.
+   or http://www.linux-magazin.de/ausgabe/1999/10/IO/io.html
+ */
+
+#include "../comedidev.h"
+#include <linux/ioport.h>
+
+#define PARPORT_SIZE 3
+
+#define PARPORT_A 0
+#define PARPORT_B 1
+#define PARPORT_C 2
+
+static int parport_attach(comedi_device * dev, comedi_devconfig * it);
+static int parport_detach(comedi_device * dev);
+static comedi_driver driver_parport = {
+      driver_name:"comedi_parport",
+      module:THIS_MODULE,
+      attach:parport_attach,
+      detach:parport_detach,
+};
+
+COMEDI_INITCLEANUP(driver_parport);
+
+typedef struct parport_private_struct {
+	unsigned int a_data;
+	unsigned int c_data;
+	int enable_irq;
+} parport_private;
+#define devpriv ((parport_private *)(dev->private))
+
+static int parport_insn_a(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	if (data[0]) {
+		devpriv->a_data &= ~data[0];
+		devpriv->a_data |= (data[0] & data[1]);
+
+		outb(devpriv->a_data, dev->iobase + PARPORT_A);
+	}
+
+	data[1] = inb(dev->iobase + PARPORT_A);
+
+	return 2;
+}
+
+static int parport_insn_config_a(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	if (data[0]) {
+		s->io_bits = 0xff;
+		devpriv->c_data &= ~(1 << 5);
+	} else {
+		s->io_bits = 0;
+		devpriv->c_data |= (1 << 5);
+	}
+	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+
+	return 1;
+}
+
+static int parport_insn_b(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	if (data[0]) {
+		// should writes be ignored?
+	}
+
+	data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
+
+	return 2;
+}
+
+static int parport_insn_c(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	data[0] &= 0x0f;
+	if (data[0]) {
+		devpriv->c_data &= ~data[0];
+		devpriv->c_data |= (data[0] & data[1]);
+
+		outb(devpriv->c_data, dev->iobase + PARPORT_C);
+	}
+
+	data[1] = devpriv->c_data & 0xf;
+
+	return 2;
+}
+
+static int parport_intr_insn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	if (insn->n < 1)
+		return -EINVAL;
+
+	data[1] = 0;
+	return 2;
+}
+
+static int parport_intr_cmdtest(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd)
+{
+	int err = 0;
+	int tmp;
+
+	/* step 1 */
+
+	tmp = cmd->start_src;
+	cmd->start_src &= TRIG_NOW;
+	if (!cmd->start_src || tmp != cmd->start_src)
+		err++;
+
+	tmp = cmd->scan_begin_src;
+	cmd->scan_begin_src &= TRIG_EXT;
+	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
+		err++;
+
+	tmp = cmd->convert_src;
+	cmd->convert_src &= TRIG_FOLLOW;
+	if (!cmd->convert_src || tmp != cmd->convert_src)
+		err++;
+
+	tmp = cmd->scan_end_src;
+	cmd->scan_end_src &= TRIG_COUNT;
+	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
+		err++;
+
+	tmp = cmd->stop_src;
+	cmd->stop_src &= TRIG_NONE;
+	if (!cmd->stop_src || tmp != cmd->stop_src)
+		err++;
+
+	if (err)
+		return 1;
+
+	/* step 2: ignored */
+
+	if (err)
+		return 2;
+
+	/* step 3: */
+
+	if (cmd->start_arg != 0) {
+		cmd->start_arg = 0;
+		err++;
+	}
+	if (cmd->scan_begin_arg != 0) {
+		cmd->scan_begin_arg = 0;
+		err++;
+	}
+	if (cmd->convert_arg != 0) {
+		cmd->convert_arg = 0;
+		err++;
+	}
+	if (cmd->scan_end_arg != 1) {
+		cmd->scan_end_arg = 1;
+		err++;
+	}
+	if (cmd->stop_arg != 0) {
+		cmd->stop_arg = 0;
+		err++;
+	}
+
+	if (err)
+		return 3;
+
+	/* step 4: ignored */
+
+	if (err)
+		return 4;
+
+	return 0;
+}
+
+static int parport_intr_cmd(comedi_device * dev, comedi_subdevice * s)
+{
+	devpriv->c_data |= 0x10;
+	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+
+	devpriv->enable_irq = 1;
+
+	return 0;
+}
+
+static int parport_intr_cancel(comedi_device * dev, comedi_subdevice * s)
+{
+	printk("parport_intr_cancel()\n");
+
+	devpriv->c_data &= ~0x10;
+	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+
+	devpriv->enable_irq = 0;
+
+	return 0;
+}
+
+static irqreturn_t parport_interrupt(int irq, void *d PT_REGS_ARG)
+{
+	comedi_device *dev = d;
+	comedi_subdevice *s = dev->subdevices + 3;
+
+	if (!devpriv->enable_irq) {
+		printk("comedi_parport: bogus irq, ignored\n");
+		return IRQ_NONE;
+	}
+
+	comedi_buf_put(s->async, 0);
+	s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
+
+	comedi_event(dev, s);
+	return IRQ_HANDLED;
+}
+
+static int parport_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	int ret;
+	unsigned int irq;
+	unsigned long iobase;
+	comedi_subdevice *s;
+
+	iobase = it->options[0];
+	printk("comedi%d: parport: 0x%04lx ", dev->minor, iobase);
+	if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
+		printk("I/O port conflict\n");
+		return -EIO;
+	}
+	dev->iobase = iobase;
+
+	irq = it->options[1];
+	if (irq) {
+		printk(" irq=%u", irq);
+		ret = comedi_request_irq(irq, parport_interrupt, 0,
+			"comedi_parport", dev);
+		if (ret < 0) {
+			printk(" irq not available\n");
+			return -EINVAL;
+		}
+		dev->irq = irq;
+	}
+	dev->board_name = "parport";
+
+	if ((ret = alloc_subdevices(dev, 4)) < 0)
+		return ret;
+	if ((ret = alloc_private(dev, sizeof(parport_private))) < 0)
+		return ret;
+
+	s = dev->subdevices + 0;
+	s->type = COMEDI_SUBD_DIO;
+	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
+	s->n_chan = 8;
+	s->maxdata = 1;
+	s->range_table = &range_digital;
+	s->insn_bits = parport_insn_a;
+	s->insn_config = parport_insn_config_a;
+
+	s = dev->subdevices + 1;
+	s->type = COMEDI_SUBD_DI;
+	s->subdev_flags = SDF_READABLE;
+	s->n_chan = 5;
+	s->maxdata = 1;
+	s->range_table = &range_digital;
+	s->insn_bits = parport_insn_b;
+
+	s = dev->subdevices + 2;
+	s->type = COMEDI_SUBD_DO;
+	s->subdev_flags = SDF_WRITABLE;
+	s->n_chan = 4;
+	s->maxdata = 1;
+	s->range_table = &range_digital;
+	s->insn_bits = parport_insn_c;
+
+	s = dev->subdevices + 3;
+	if (irq) {
+		dev->read_subdev = s;
+		s->type = COMEDI_SUBD_DI;
+		s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
+		s->n_chan = 1;
+		s->maxdata = 1;
+		s->range_table = &range_digital;
+		s->insn_bits = parport_intr_insn;
+		s->do_cmdtest = parport_intr_cmdtest;
+		s->do_cmd = parport_intr_cmd;
+		s->cancel = parport_intr_cancel;
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	devpriv->a_data = 0;
+	outb(devpriv->a_data, dev->iobase + PARPORT_A);
+	devpriv->c_data = 0;
+	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+
+	printk("\n");
+	return 1;
+}
+
+static int parport_detach(comedi_device * dev)
+{
+	printk("comedi%d: parport: remove\n", dev->minor);
+
+	if (dev->iobase)
+		release_region(dev->iobase, PARPORT_SIZE);
+
+	if (dev->irq)
+		comedi_free_irq(dev->irq, dev);
+
+	return 0;
+}