ddi_prop_exists(9f)

1ddi_prop_exists(9F)      Kernel Functions for Drivers      ddi_prop_exists(9F)
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NAME

6       ddi_prop_exists - check for the existence of a property
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SYNOPSIS

9       #include <sys/ddi.h>
10       #include <sys/sunddi.h>
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14       int ddi_prop_exists(dev_t match_dev, dev_info_t *dip, uint_t flags,
15            char *name);
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INTERFACE LEVEL

19       Solaris DDI specific (Solaris DDI).
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PARAMETERS

22       match_dev     Device number associated with property or DDI_DEV_T_ANY.
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25       dip           Pointer  to the device info node of device whose property
26                     list should be searched.
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29       flags         Possible flag values are some combination of:
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31                     DDI_PROP_DONTPASS     Do  not  pass  request  to   parent
32                                           device   information  node  if  the
33                                           property  is not found.
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36                     DDI_PROP_NOTPROM      Do not  look  at   PROM  properties
37                                           (ignored  on  platforms that do not
38                                           support  PROM properties).
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42       name          String containing the name of the property.
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DESCRIPTION

46       ddi_prop_exists() checks for the existence of a property regardless  of
47       the property value data type.
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50       Properties are searched for based on the dip, name, and  match_dev. The
51       property search order is as follows:
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53           1.     Search software properties created by the driver.
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55           2.     Search the software properties created  by  the  system  (or
56                  nexus nodes in the device info tree).
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58           3.     Search the driver global properties list.
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60           4.     If  DDI_PROP_NOTPROM  is not set, search the PROM properties
61                  (if they exist).
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63           5.     If DDI_PROP_DONTPASS is not set, pass this  request  to  the
64                  parent device information node.
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66           6.     Return 0 if not found and 1 if found.
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69       Usually, the match_dev argument should be set to the actual device num‐
70       ber that this property is associated with.  However, if the   match_dev
71       argument  is  DDI_DEV_T_ANY,  then   ddi_prop_exists()  will  match the
72       request  regardless of the  match_dev the property  was  created  with.
73       That  is  the  first property whose name matches name will be returned.
74       If a property was created with  match_dev set to   DDI_DEV_T_NONE  then
75       the  only  way  to  look  up  this property is with a  match_dev set to
76       DDI_DEV_T_ANY. PROM properties are always created with match_dev set to
77       DDI_DEV_T_NONE.
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80       name must always be set to the name of the property being looked up.
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RETURN VALUES

83       ddi_prop_exists() returns  1 if the property exists and  0 otherwise.
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CONTEXT

86       These functions can be called from user or kernel context.
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EXAMPLES

89       Example 1 : Using ddi_prop_exists()
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92       The following example demonstrates the use of  ddi_prop_exists().
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95         /*
96              * Enable "whizzy" mode if the "whizzy-mode" property exists
97              */
98              if (ddi_prop_exists(xx_dev, xx_dip, DDI_PROP_NOTPROM,
99                      "whizzy-mode") == 1) {
100                    xx_enable_whizzy_mode(xx_dip);
101              } else {
102                    xx_disable_whizzy_mode(xx_dip);
103              }
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