1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * comedi/range.c
  4 * comedi routines for voltage ranges
  5 *
  6 * COMEDI - Linux Control and Measurement Device Interface
  7 * Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
  8 */
  9
 10#include <linux/uaccess.h>
 11#include <linux/comedi/comedidev.h>
 12#include "comedi_internal.h"
 13
 14const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
 15EXPORT_SYMBOL_GPL(range_bipolar10);
 16const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
 17EXPORT_SYMBOL_GPL(range_bipolar5);
 18const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
 19EXPORT_SYMBOL_GPL(range_bipolar2_5);
 20const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
 21EXPORT_SYMBOL_GPL(range_unipolar10);
 22const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
 23EXPORT_SYMBOL_GPL(range_unipolar5);
 24const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
 25EXPORT_SYMBOL_GPL(range_unipolar2_5);
 26const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
 27EXPORT_SYMBOL_GPL(range_0_20mA);
 28const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
 29EXPORT_SYMBOL_GPL(range_4_20mA);
 30const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
 31EXPORT_SYMBOL_GPL(range_0_32mA);
 32const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
 33EXPORT_SYMBOL_GPL(range_unknown);
 34
 35/*
 36 * COMEDI_RANGEINFO ioctl
 37 * range information
 38 *
 39 * arg:
 40 *	pointer to comedi_rangeinfo structure
 41 *
 42 * reads:
 43 *	comedi_rangeinfo structure
 44 *
 45 * writes:
 46 *	array of comedi_krange structures to rangeinfo->range_ptr pointer
 47 */
 48int do_rangeinfo_ioctl(struct comedi_device *dev,
 49		       struct comedi_rangeinfo *it)
 50{
 51	int subd, chan;
 52	const struct comedi_lrange *lr;
 53	struct comedi_subdevice *s;
 54
 55	subd = (it->range_type >> 24) & 0xf;
 56	chan = (it->range_type >> 16) & 0xff;
 57
 58	if (!dev->attached)
 59		return -EINVAL;
 60	if (subd >= dev->n_subdevices)
 61		return -EINVAL;
 62	s = &dev->subdevices[subd];
 63	if (s->range_table) {
 64		lr = s->range_table;
 65	} else if (s->range_table_list) {
 66		if (chan >= s->n_chan)
 67			return -EINVAL;
 68		lr = s->range_table_list[chan];
 69	} else {
 70		return -EINVAL;
 71	}
 72
 73	if (RANGE_LENGTH(it->range_type) != lr->length) {
 74		dev_dbg(dev->class_dev,
 75			"wrong length %d should be %d (0x%08x)\n",
 76			RANGE_LENGTH(it->range_type),
 77			lr->length, it->range_type);
 78		return -EINVAL;
 79	}
 80
 81	if (copy_to_user(it->range_ptr, lr->range,
 82			 sizeof(struct comedi_krange) * lr->length))
 83		return -EFAULT;
 84
 85	return 0;
 86}
 87
 88/**
 89 * comedi_check_chanlist() - Validate each element in a chanlist.
 90 * @s: comedi_subdevice struct
 91 * @n: number of elements in the chanlist
 92 * @chanlist: the chanlist to validate
 93 *
 94 * Each element consists of a channel number, a range index, an analog
 95 * reference type and some flags, all packed into an unsigned int.
 96 *
 97 * This checks that the channel number and range index are supported by
 98 * the comedi subdevice.  It does not check whether the analog reference
 99 * type and the flags are supported.  Drivers that care should check those
100 * themselves.
101 *
102 * Return: %0 if all @chanlist elements are valid (success),
103 *         %-EINVAL if one or more elements are invalid.
104 */
105int comedi_check_chanlist(struct comedi_subdevice *s, int n,
106			  unsigned int *chanlist)
107{
108	struct comedi_device *dev = s->device;
109	unsigned int chanspec;
110	int chan, range_len, i;
111
112	for (i = 0; i < n; i++) {
113		chanspec = chanlist[i];
114		chan = CR_CHAN(chanspec);
115		if (s->range_table)
116			range_len = s->range_table->length;
117		else if (s->range_table_list && chan < s->n_chan)
118			range_len = s->range_table_list[chan]->length;
119		else
120			range_len = 0;
121		if (chan >= s->n_chan ||
122		    CR_RANGE(chanspec) >= range_len) {
123			dev_warn(dev->class_dev,
124				 "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
125				 i, chanspec, chan, range_len);
126			return -EINVAL;
127		}
128	}
129	return 0;
130}
131EXPORT_SYMBOL_GPL(comedi_check_chanlist);