Staging: comedi: add dt2817 driver

Driver for DataTranslation DT2817

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

drivers/staging/comedi/drivers/dt2817.c

+/*
+    comedi/drivers/dt2817.c
+    Hardware driver for Data Translation DT2817
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 1998 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: dt2817
+Description: Data Translation DT2817
+Author: ds
+Status: complete
+Devices: [Data Translation] DT2817 (dt2817)
+
+A very simple digital I/O card.  Four banks of 8 lines, each bank
+is configurable for input or output.  One wonders why it takes a
+50 page manual to describe this thing.
+
+The driver (which, btw, is much less than 50 pages) has 1 subdevice
+with 32 channels, configurable in groups of 8.
+
+Configuration options:
+  [0] - I/O port base base address
+*/
+
+#include "../comedidev.h"
+
+#include <linux/ioport.h>
+
+#define DT2817_SIZE 5
+
+#define DT2817_CR 0
+#define DT2817_DATA 1
+
+static int dt2817_attach(comedi_device * dev, comedi_devconfig * it);
+static int dt2817_detach(comedi_device * dev);
+static comedi_driver driver_dt2817 = {
+      driver_name:"dt2817",
+      module:THIS_MODULE,
+      attach:dt2817_attach,
+      detach:dt2817_detach,
+};
+
+COMEDI_INITCLEANUP(driver_dt2817);
+
+static int dt2817_dio_insn_config(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int mask;
+	int chan;
+	int oe = 0;
+
+	if (insn->n != 1)
+		return -EINVAL;
+
+	chan = CR_CHAN(insn->chanspec);
+	if (chan < 8) {
+		mask = 0xff;
+	} else if (chan < 16) {
+		mask = 0xff00;
+	} else if (chan < 24) {
+		mask = 0xff0000;
+	} else
+		mask = 0xff000000;
+	if (data[0])
+		s->io_bits |= mask;
+	else
+		s->io_bits &= ~mask;
+
+	if (s->io_bits & 0x000000ff)
+		oe |= 0x1;
+	if (s->io_bits & 0x0000ff00)
+		oe |= 0x2;
+	if (s->io_bits & 0x00ff0000)
+		oe |= 0x4;
+	if (s->io_bits & 0xff000000)
+		oe |= 0x8;
+
+	outb(oe, dev->iobase + DT2817_CR);
+
+	return 1;
+}
+
+static int dt2817_dio_insn_bits(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	unsigned int changed;
+
+	/* It's questionable whether it is more important in
+	 * a driver like this to be deterministic or fast.
+	 * We choose fast. */
+
+	if (data[0]) {
+		changed = s->state;
+		s->state &= ~data[0];
+		s->state |= (data[0] & data[1]);
+		changed ^= s->state;
+		changed &= s->io_bits;
+		if (changed & 0x000000ff)
+			outb(s->state & 0xff, dev->iobase + DT2817_DATA + 0);
+		if (changed & 0x0000ff00)
+			outb((s->state >> 8) & 0xff,
+				dev->iobase + DT2817_DATA + 1);
+		if (changed & 0x00ff0000)
+			outb((s->state >> 16) & 0xff,
+				dev->iobase + DT2817_DATA + 2);
+		if (changed & 0xff000000)
+			outb((s->state >> 24) & 0xff,
+				dev->iobase + DT2817_DATA + 3);
+	}
+	data[1] = inb(dev->iobase + DT2817_DATA + 0);
+	data[1] |= (inb(dev->iobase + DT2817_DATA + 1) << 8);
+	data[1] |= (inb(dev->iobase + DT2817_DATA + 2) << 16);
+	data[1] |= (inb(dev->iobase + DT2817_DATA + 3) << 24);
+
+	return 2;
+}
+
+static int dt2817_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	int ret;
+	comedi_subdevice *s;
+	unsigned long iobase;
+
+	iobase = it->options[0];
+	printk("comedi%d: dt2817: 0x%04lx ", dev->minor, iobase);
+	if (!request_region(iobase, DT2817_SIZE, "dt2817")) {
+		printk("I/O port conflict\n");
+		return -EIO;
+	}
+	dev->iobase = iobase;
+	dev->board_name = "dt2817";
+
+	if ((ret = alloc_subdevices(dev, 1)) < 0)
+		return ret;
+
+	s = dev->subdevices + 0;
+
+	s->n_chan = 32;
+	s->type = COMEDI_SUBD_DIO;
+	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
+	s->range_table = &range_digital;
+	s->maxdata = 1;
+	s->insn_bits = dt2817_dio_insn_bits;
+	s->insn_config = dt2817_dio_insn_config;
+
+	s->state = 0;
+	outb(0, dev->iobase + DT2817_CR);
+
+	printk("\n");
+
+	return 0;
+}
+
+static int dt2817_detach(comedi_device * dev)
+{
+	printk("comedi%d: dt2817: remove\n", dev->minor);
+
+	if (dev->iobase)
+		release_region(dev->iobase, DT2817_SIZE);
+
+	return 0;
+}