linux-stable/drivers/comedi/range.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* comedi/range.c
* comedi routines for voltage ranges
*
* COMEDI - Linux Control and Measurement Device Interface
* Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
*/
#include <linux/uaccess.h>
#include <linux/comedi/comedidev.h>
#include "comedi_internal.h"
const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
EXPORT_SYMBOL_GPL(range_bipolar10);
const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
EXPORT_SYMBOL_GPL(range_bipolar5);
const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
EXPORT_SYMBOL_GPL(range_bipolar2_5);
const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
EXPORT_SYMBOL_GPL(range_unipolar10);
const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
EXPORT_SYMBOL_GPL(range_unipolar5);
const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
EXPORT_SYMBOL_GPL(range_unipolar2_5);
const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
EXPORT_SYMBOL_GPL(range_0_20mA);
const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
EXPORT_SYMBOL_GPL(range_4_20mA);
const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
EXPORT_SYMBOL_GPL(range_0_32mA);
const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
EXPORT_SYMBOL_GPL(range_unknown);
/*
* COMEDI_RANGEINFO ioctl
* range information
*
* arg:
* pointer to comedi_rangeinfo structure
*
* reads:
* comedi_rangeinfo structure
*
* writes:
* array of comedi_krange structures to rangeinfo->range_ptr pointer
*/
int do_rangeinfo_ioctl(struct comedi_device *dev,
struct comedi_rangeinfo *it)
{
int subd, chan;
const struct comedi_lrange *lr;
struct comedi_subdevice *s;
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) {
dev_dbg(dev->class_dev,
"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(struct comedi_krange) * lr->length))
return -EFAULT;
return 0;
}
/**
* comedi_check_chanlist() - Validate each element in a chanlist.
* @s: comedi_subdevice struct
* @n: number of elements in the chanlist
* @chanlist: the chanlist to validate
*
* Each element consists of a channel number, a range index, an analog
* reference type and some flags, all packed into an unsigned int.
*
* This checks that the channel number and range index are supported by
* the comedi subdevice. It does not check whether the analog reference
* type and the flags are supported. Drivers that care should check those
* themselves.
*
* Return: %0 if all @chanlist elements are valid (success),
* %-EINVAL if one or more elements are invalid.
*/
int comedi_check_chanlist(struct comedi_subdevice *s, int n,
unsigned int *chanlist)
{
struct comedi_device *dev = s->device;
unsigned int chanspec;
int chan, range_len, i;
for (i = 0; i < n; i++) {
chanspec = chanlist[i];
chan = CR_CHAN(chanspec);
if (s->range_table)
range_len = s->range_table->length;
else if (s->range_table_list && chan < s->n_chan)
range_len = s->range_table_list[chan]->length;
else
range_len = 0;
if (chan >= s->n_chan ||
CR_RANGE(chanspec) >= range_len) {
dev_warn(dev->class_dev,
"bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
i, chanspec, chan, range_len);
return -EINVAL;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(comedi_check_chanlist);