hwgraph.dev(D3X)hwgraph.dev(D3X)NAME
hwgraph.dev: hwgraph_block_device_add, hwgraph_char_device_add,
hwgraph_chmod, device_info_set, device_info_get - create and use device
vertex
SYNOPSIS
#include <sys/types.h>
#include <sys/hwgraph.h>
#include <sys/ddi.h>
graph_error_t
hwgraph_block_device_add(vertex_hdl_t from_vhdl,
char *path,
char *driver_prefix,
vertex_hdl_t *vhdl_ptr);
graph_error_t
hwgraph_char_device_add(vertex_hdl_t from_vhdl,
char *path,
char *driver_prefix,
vertex_hdl_t *vhdl_ptr);
void
device_info_set(vertex_hdl_t device, void *info);
void *
device_info_get(vertex_hdl_t device);
void
hwgraph_chmod(vertex_hdl_t vhdl, mode_t mode);
Arguments
device Vertex handle of a device vertex, typically one created by
hwgraph_block_device_add() or hwgraph_char_device_add().
driver_prefix
The device driver character string prefix of the device
driver that is to manage the newly-created device.
from_vhdl Vertex handle that is the connection point of the device to
be described. Typically the vertex handle passed to the
attach entry point of a device driver.
mode A standard file protection mode as declared in sys/stat.h.
path An edge name, or a sequence of edge names separated by
slashes (which looks exactly like a relative pathname in the
/hw filesystem).
vhdl A vertex handle of a device in the hwgraph.
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hwgraph.dev(D3X)hwgraph.dev(D3X)
vhdl_ptr A pointer to a field where a new vertex handle is returned.
DESCRIPTION
The device_add functions operate on the hardware graph to add a new
vertex that represents a block or a char device. The new vertex is
visible in /hw as a character or block device special file. The device
is controlled by the device driver that is identified by prefix, so that
prefix_open() is called when the new vertex is opened. When it is
opened, the dev_t passed to the driver's open entry point matches the
vertex_hdl_t returned in vhdl_ptr.
The device_info_set() function associates a pointer-sized piece of
information with a specified dev_t for later retrieval by
device_info_get(). Typically, this information is a pointer to a per-
device data structure allocated by the driver in its attach entry point.
Caution: A device driver should never change the device-info of any
vertex that the device driver did not create. In particular, the vertex
that is passed to the attach() entry point of a PCI driver is owned by
the PCI infrastructure. If the driver sets the device-info of that
connection-point vertex, the PCI infrastructure is likely to crash. A
driver is always free to change the device-info of a vertex that the
driver itself creates using the device_add functions.
hwgraph_chmod() sets the initial (default) access mode of the /hw
representation of the specified vertex.
DIAGNOSTICS
The *_device_add functions return GRAPH_SUCCESS when the operation
completes successfully, or a failure code as listed in hwgraph(D3X) when
the operation does not complete successfully.
device_info_set() always succeeds and has no return value. It is the
caller's responsibility to pass a valid device; that is, a dev_t that
represents a vertex in the hardware graph.
device_info_get() returns the pointer-sized piece of information
associated with the specified device. This value is unpredictable until
device_info_set() has been called.
SEE ALSOhwgraph.inv(D3X), hwgraph.intro(D4X).
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