Staging: add comedi core

This adds the Comedi core to the staging tree.
This is a data acquision infrastructure for Linux, providing a common
interface for these types of drivers.

Taken directly from the comedi git tree, with only minor tweaks
by Greg to get it to build properly within the kernel tree.

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

1 files changed, 161 insertions, 0 deletions

diff --git a/drivers/staging/comedi/range.c b/drivers/staging/comedi/range.c
new file mode 100644
index 00000000000..61dc3cd6a9f
--- /dev/null
+++ b/drivers/staging/comedi/range.c
@@ -0,0 +1,161 @@
+/*
+    module/range.c
+    comedi routines for voltage ranges
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 1997-8 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.
+
+*/
+
+#include "comedidev.h"
+#include <asm/uaccess.h>
+
+const comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
+const comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
+const comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
+const comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
+const comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
+const comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none}} };
+
+/*
+   	COMEDI_RANGEINFO
+	range information ioctl
+
+	arg:
+		pointer to rangeinfo structure
+
+	reads:
+		range info structure
+
+	writes:
+		n comedi_krange structures to rangeinfo->range_ptr
+*/
+int do_rangeinfo_ioctl(comedi_device * dev, comedi_rangeinfo * arg)
+{
+	comedi_rangeinfo it;
+	int subd, chan;
+	const comedi_lrange *lr;
+	comedi_subdevice *s;
+
+	if (copy_from_user(&it, arg, sizeof(comedi_rangeinfo)))
+		return -EFAULT;
+	subd = (it.range_type >> 24) & 0xf;
+	chan = (it.range_type >> 16) & 0xff;
+
+	if (!dev->attached)
+		return -EINVAL;
+	if (subd >= dev->n_subdevices)
+		return -EINVAL;
+	s = dev->subdevices + subd;
+	if (s->range_table) {
+		lr = s->range_table;
+	} else if (s->range_table_list) {
+		if (chan >= s->n_chan)
+			return -EINVAL;
+		lr = s->range_table_list[chan];
+	} else {
+		return -EINVAL;
+	}
+
+	if (RANGE_LENGTH(it.range_type) != lr->length) {
+		DPRINTK("wrong length %d should be %d (0x%08x)\n",
+			RANGE_LENGTH(it.range_type), lr->length, it.range_type);
+		return -EINVAL;
+	}
+
+	if (copy_to_user(it.range_ptr, lr->range,
+			sizeof(comedi_krange) * lr->length))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int aref_invalid(comedi_subdevice * s, unsigned int chanspec)
+{
+	unsigned int aref;
+
+	// disable reporting invalid arefs... maybe someday
+	return 0;
+
+	aref = CR_AREF(chanspec);
+	switch (aref) {
+	case AREF_DIFF:
+		if (s->subdev_flags & SDF_DIFF)
+			return 0;
+		break;
+	case AREF_COMMON:
+		if (s->subdev_flags & SDF_COMMON)
+			return 0;
+		break;
+	case AREF_GROUND:
+		if (s->subdev_flags & SDF_GROUND)
+			return 0;
+		break;
+	case AREF_OTHER:
+		if (s->subdev_flags & SDF_OTHER)
+			return 0;
+		break;
+	default:
+		break;
+	}
+	DPRINTK("subdevice does not support aref %i", aref);
+	return 1;
+}
+
+/*
+   This function checks each element in a channel/gain list to make
+   make sure it is valid.
+*/
+int check_chanlist(comedi_subdevice * s, int n, unsigned int *chanlist)
+{
+	int i;
+	int chan;
+
+	if (s->range_table) {
+		for (i = 0; i < n; i++)
+			if (CR_CHAN(chanlist[i]) >= s->n_chan ||
+				CR_RANGE(chanlist[i]) >= s->range_table->length
+				|| aref_invalid(s, chanlist[i])) {
+				rt_printk
+					("bad chanlist[%d]=0x%08x n_chan=%d range length=%d\n",
+					i, chanlist[i], s->n_chan,
+					s->range_table->length);
+#if 0
+				for (i = 0; i < n; i++) {
+					printk("[%d]=0x%08x\n", i, chanlist[i]);
+				}
+#endif
+				return -EINVAL;
+			}
+	} else if (s->range_table_list) {
+		for (i = 0; i < n; i++) {
+			chan = CR_CHAN(chanlist[i]);
+			if (chan >= s->n_chan ||
+				CR_RANGE(chanlist[i]) >=
+				s->range_table_list[chan]->length
+				|| aref_invalid(s, chanlist[i])) {
+				rt_printk("bad chanlist[%d]=0x%08x\n", i,
+					chanlist[i]);
+				return -EINVAL;
+			}
+		}
+	} else {
+		rt_printk("comedi: (bug) no range type list!\n");
+		return -EINVAL;
+	}
+	return 0;
+}