1/*
  2    module/range.c
  3    comedi routines for voltage ranges
  4
  5    COMEDI - Linux Control and Measurement Device Interface
  6    Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
  7
  8    This program is free software; you can redistribute it and/or modify
  9    it under the terms of the GNU General Public License as published by
 10    the Free Software Foundation; either version 2 of the License, or
 11    (at your option) any later version.
 12
 13    This program is distributed in the hope that it will be useful,
 14    but WITHOUT ANY WARRANTY; without even the implied warranty of
 15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16    GNU General Public License for more details.
 17*/
 18
 19#include <linux/uaccess.h>
 20#include "comedidev.h"
 21#include "comedi_internal.h"
 22
 23const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
 24EXPORT_SYMBOL_GPL(range_bipolar10);
 25const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
 26EXPORT_SYMBOL_GPL(range_bipolar5);
 27const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
 28EXPORT_SYMBOL_GPL(range_bipolar2_5);
 29const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
 30EXPORT_SYMBOL_GPL(range_unipolar10);
 31const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
 32EXPORT_SYMBOL_GPL(range_unipolar5);
 33const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
 34EXPORT_SYMBOL_GPL(range_unipolar2_5);
 35const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
 36EXPORT_SYMBOL_GPL(range_0_20mA);
 37const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
 38EXPORT_SYMBOL_GPL(range_4_20mA);
 39const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
 40EXPORT_SYMBOL_GPL(range_0_32mA);
 41const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
 42EXPORT_SYMBOL_GPL(range_unknown);
 43
 44/*
 45	COMEDI_RANGEINFO
 46	range information ioctl
 47
 48	arg:
 49		pointer to rangeinfo structure
 50
 51	reads:
 52		range info structure
 53
 54	writes:
 55		n struct comedi_krange structures to rangeinfo->range_ptr
 56*/
 57int do_rangeinfo_ioctl(struct comedi_device *dev,
 58		       struct comedi_rangeinfo __user *arg)
 59{
 60	struct comedi_rangeinfo it;
 61	int subd, chan;
 62	const struct comedi_lrange *lr;
 63	struct comedi_subdevice *s;
 64
 65	if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
 66		return -EFAULT;
 67	subd = (it.range_type >> 24) & 0xf;
 68	chan = (it.range_type >> 16) & 0xff;
 69
 70	if (!dev->attached)
 71		return -EINVAL;
 72	if (subd >= dev->n_subdevices)
 73		return -EINVAL;
 74	s = &dev->subdevices[subd];
 75	if (s->range_table) {
 76		lr = s->range_table;
 77	} else if (s->range_table_list) {
 78		if (chan >= s->n_chan)
 79			return -EINVAL;
 80		lr = s->range_table_list[chan];
 81	} else {
 82		return -EINVAL;
 83	}
 84
 85	if (RANGE_LENGTH(it.range_type) != lr->length) {
 86		dev_dbg(dev->class_dev,
 87			"wrong length %d should be %d (0x%08x)\n",
 88			RANGE_LENGTH(it.range_type),
 89			lr->length, it.range_type);
 90		return -EINVAL;
 91	}
 92
 93	if (copy_to_user(it.range_ptr, lr->range,
 94			 sizeof(struct comedi_krange) * lr->length))
 95		return -EFAULT;
 96
 97	return 0;
 98}
 99
100static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
101{
102	unsigned int aref;
103
104	/*  disable reporting invalid arefs... maybe someday */
105	return 0;
106
107	aref = CR_AREF(chanspec);
108	switch (aref) {
109	case AREF_DIFF:
110		if (s->subdev_flags & SDF_DIFF)
111			return 0;
112		break;
113	case AREF_COMMON:
114		if (s->subdev_flags & SDF_COMMON)
115			return 0;
116		break;
117	case AREF_GROUND:
118		if (s->subdev_flags & SDF_GROUND)
119			return 0;
120		break;
121	case AREF_OTHER:
122		if (s->subdev_flags & SDF_OTHER)
123			return 0;
124		break;
125	default:
126		break;
127	}
128	dev_dbg(s->device->class_dev, "subdevice does not support aref %i",
129		aref);
130	return 1;
131}
132
133/**
134 * comedi_check_chanlist() - Validate each element in a chanlist.
135 * @s: comedi_subdevice struct
136 * @n: number of elements in the chanlist
137 * @chanlist: the chanlist to validate
138*/
139int comedi_check_chanlist(struct comedi_subdevice *s, int n,
140			  unsigned int *chanlist)
141{
142	struct comedi_device *dev = s->device;
143	unsigned int chanspec;
144	int chan, range_len, i;
145
146	for (i = 0; i < n; i++) {
147		chanspec = chanlist[i];
148		chan = CR_CHAN(chanspec);
149		if (s->range_table)
150			range_len = s->range_table->length;
151		else if (s->range_table_list && chan < s->n_chan)
152			range_len = s->range_table_list[chan]->length;
153		else
154			range_len = 0;
155		if (chan >= s->n_chan ||
156		    CR_RANGE(chanspec) >= range_len ||
157		    aref_invalid(s, chanspec)) {
158			dev_warn(dev->class_dev,
159				 "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
160				 i, chanspec, chan, range_len);
161			return -EINVAL;
162		}
163	}
164	return 0;
165}
166EXPORT_SYMBOL_GPL(comedi_check_chanlist);