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path: root/drivers/comedi/range.c
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Diffstat (limited to 'drivers/comedi/range.c')
-rw-r--r--drivers/comedi/range.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/comedi/range.c b/drivers/comedi/range.c
new file mode 100644
index 000000000000..a4e6fe0fb729
--- /dev/null
+++ b/drivers/comedi/range.c
@@ -0,0 +1,131 @@
+// 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 "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);