range.c 3.8 KB

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