ddi_prop_op(9F) Kernel Functions for Drivers ddi_prop_op(9F)NAME
ddi_prop_op, ddi_getprop, ddi_getlongprop, ddi_getlongprop_buf,
ddi_getproplen - get property information for leaf device drivers
SYNOPSIS
#include <sys/types.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op, int
flags, char *name, caddr_t valuep, int *lengthp);
int ddi_getprop(dev_t dev, dev_info_t *dip, int flags, char *name, int
defvalue);
int ddi_getlongprop(dev_t dev, dev_info_t *dip, int flags, char *name,
caddr_t valuep, int *lengthp);
int ddi_getlongprop_buf(dev_t dev, dev_info_t *dip, int flags, char
*name, caddr_t valuep, int *lengthp);
int ddi_getproplen(dev_t dev, dev_info_t *dip, int flags, char *name,
int *lengthp);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI). The ddi_getlongprop(), ddi_getlong‐
prop_buf(), ddi_getprop(), and ddi_getproplen() functions are obsolete.
Use ddi_prop_lookup(9F) instead of ddi_getlongprop(), ddi_getlong‐
prop_buf(), and ddi_getproplen(). Use ddi_prop_get_int(9F) instead of
ddi_getprop()PARAMETERS
dev Device number associated with property or DDI_DEV_T_ANY as the
wildcard device number.
dip Pointer to a device info node.
prop_op Property operator.
flags Possible flag values are some combination of:
DDI_PROP_DONTPASS
do not pass request to parent device information node if
property not found
DDI_PROP_CANSLEEP
the routine may sleep while allocating memory
DDI_PROP_NOTPROM
do not look at PROM properties (ignored on architectures
that do not support PROM properties)
name String containing the name of the property.
valuep If prop_op is PROP_LEN_AND_VAL_BUF, this should be a pointer
to the users buffer. If prop_op is PROP_LEN_AND_VAL_ALLOC,
this should be the address of a pointer.
lengthp On exit, *lengthp will contain the property length. If prop_op
is PROP_LEN_AND_VAL_BUF then before calling ddi_prop_op(),
lengthp should point to an int that contains the length of
callers buffer.
defvalue The value that ddi_getprop() returns if the property is not
found.
DESCRIPTION
The ddi_prop_op() function gets arbitrary-size properties for leaf
devices. The routine searches the device's property list. If it does
not find the property at the device level, it examines the flags argu‐
ment, and if DDI_PROP_DONTPASS is set, then ddi_prop_op() returns
DDI_PROP_NOT_FOUND. Otherwise, it passes the request to the next level
of the device info tree. If it does find the property, but the property
has been explicitly undefined, it returns DDI_PROP_UNDEFINED. Otherwise
it returns either the property length, or both the length and value of
the property to the caller via the valuep and lengthp pointers, depend‐
ing on the value of prop_op, as described below, and returns
DDI_PROP_SUCCESS. If a property cannot be found at all,
DDI_PROP_NOT_FOUND is returned.
Usually, the dev argument should be set to the actual device number
that this property applies to. However, if the dev argument is
DDI_DEV_T_ANY, the wildcard dev, then ddi_prop_op() will match the
request based on name only (regardless of the actual dev the property
was created with). This property/dev match is done according to the
property search order which is to first search software properties cre‐
ated by the driver in last-in, first-out (LIFO) order, next search
software properties created by the system in LIFO order, then search
PROM properties if they exist in the system architecture.
Property operations are specified by the prop_op argument. If prop_op
is PROP_LEN, then ddi_prop_op() just sets the callers length, *lengthp,
to the property length and returns the value DDI_PROP_SUCCESS to the
caller. The valuep argument is not used in this case. Property lengths
are 0 for boolean properties, sizeof(int) for integer properties, and
size in bytes for long (variable size) properties.
If prop_op is PROP_LEN_AND_VAL_BUF, then valuep should be a pointer to
a user-supplied buffer whose length should be given in *lengthp by the
caller. If the requested property exists, ddi_prop_op() first sets
*lengthp to the property length. It then examines the size of the buf‐
fer supplied by the caller, and if it is large enough, copies the prop‐
erty value into that buffer, and returns DDI_PROP_SUCCESS. If the named
property exists but the buffer supplied is too small to hold it, it
returns DDI_PROP_BUF_TOO_SMALL.
If prop_op is PROP_LEN_AND_VAL_ALLOC, and the property is found,
ddi_prop_op() sets *lengthp to the property length. It then attempts to
allocate a buffer to return to the caller using the kmem_alloc(9F) rou‐
tine, so that memory can be later recycled using kmem_free(9F). The
driver is expected to call kmem_free() with the returned address and
size when it is done using the allocated buffer. If the allocation is
successful, it sets *valuep to point to the allocated buffer, copies
the property value into the buffer and returns DDI_PROP_SUCCESS. Other‐
wise, it returns DDI_PROP_NO_MEMORY. Note that the flags argument may
affect the behavior of memory allocation in ddi_prop_op(). In particu‐
lar, if DDI_PROP_CANSLEEP is set, then the routine will wait until mem‐
ory is available to copy the requested property.
The ddi_getprop() function returns boolean and integer-size properties.
It is a convenience wrapper for ddi_prop_op() with prop_op set to
PROP_LEN_AND_VAL_BUF, and the buffer is provided by the wrapper. By
convention, this function returns a 1 for boolean (zero-length) proper‐
ties.
The ddi_getlongprop() function returns arbitrary-size properties. It is
a convenience wrapper for ddi_prop_op() with prop_op set to
PROP_LEN_AND_VAL_ALLOC, so that the routine will allocate space to hold
the buffer that will be returned to the caller via *valuep.
The ddi_getlongprop_buf() function returns arbitrary-size properties.
It is a convenience wrapper for ddi_prop_op() with prop_op set to
PROP_LEN_AND_VAL_BUF so the user must supply a buffer.
The ddi_getproplen() function returns the length of a given property.
It is a convenience wrapper for ddi_prop_op() with prop_op set to
PROP_LEN.
RETURN VALUES
The ddi_prop_op(), ddi_getlongprop(), ddi_getlongprop_buf(), and
ddi_getproplen() functions return:
DDI_PROP_SUCCESS Property found and returned.
DDI_PROP_NOT_FOUND Property not found.
DDI_PROP_UNDEFINED Property already explicitly undefined.
DDI_PROP_NO_MEMORY Property found, but unable to allocate
memory. lengthp points to the correct
property length.
DDI_PROP_BUF_TOO_SMALL Property found, but the supplied buffer
is too small. lengthp points to the
correct property length.
The ddi_getprop() function returns:
The value of the property or the value passed into the routine as def‐
value if the property is not found. By convention, the value of zero
length properties (boolean properties) are returned as the integer
value 1.
CONTEXT
These functions can be called from user, interrupt, or kernel context,
provided DDI_PROP_CANSLEEP is not set; if it is set, they cannot be
called from interrupt context.
ATTRIBUTES
See attributes(5) for a description of the following attributes:
┌───────────────────────────┬───────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────────────────┼───────────────────────────────┤
│Stability Level │ddi_getlongprop(), ddi_get‐ │
│ │longprop_buf(), ddi_getprop(), │
│ │and ddi_getproplen() functions │
│ │are Obsolete │
└───────────────────────────┴───────────────────────────────┘
SEE ALSOattributes(5), ddi_prop_create(9F), ddi_prop_get_int(9F),
ddi_prop_lookup(9F), kmem_alloc(9F), kmem_free(9F)
Writing Device Drivers
SunOS 5.10 16 Jan 2006 ddi_prop_op(9F)
