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drm: Document how to register devices without struct drm_bus 

With the recent addition of the drm_set_unique() function, devices can
now be registered without requiring a drm_bus. Add a brief description
to the DRM docbook to show how that can be achieved.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Thierry Reding 2014-04-23 11:52:10 +02:00
parent c6a1af8a16
commit b528ae7190
1 changed files with 26 additions and 0 deletions
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26
Documentation/DocBook/drm.tmpl
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@ -141,6 +141,12 @@
and then pass it to one of the <function>drm_*_init()</function> functions
to register it with the DRM subsystem.
</para>
<para>
Newer drivers that no longer require a <structname>drm_bus</structname>
structure can alternatively use the low-level device initialization and
registration functions such as <function>drm_dev_alloc()</function> and
<function>drm_dev_register()</function> directly.
</para>
<para>
The <structname>drm_driver</structname> structure contains static
information that describes the driver and features it supports, and
@ -290,6 +296,26 @@ char *date;</synopsis>
!Edrivers/gpu/drm/drm_pci.c
!Edrivers/gpu/drm/drm_usb.c
!Edrivers/gpu/drm/drm_platform.c
<para>
New drivers that no longer rely on the services provided by the
<structname>drm_bus</structname> structure can call the low-level
device registration functions directly. The
<function>drm_dev_alloc()</function> function can be used to allocate
and initialize a new <structname>drm_device</structname> structure.
Drivers will typically want to perform some additional setup on this
structure, such as allocating driver-specific data and storing a
pointer to it in the DRM device's <structfield>dev_private</structfield>
field. Drivers should also set the device's unique name using the
<function>drm_dev_set_unique()</function> function. After it has been
set up a device can be registered with the DRM subsystem by calling
<function>drm_dev_register()</function>. This will cause the device to
be exposed to userspace and will call the driver's
<structfield>.load()</structfield> implementation. When a device is
removed, the DRM device can safely be unregistered and freed by calling
<function>drm_dev_unregister()</function> followed by a call to
<function>drm_dev_unref()</function>.
</para>
!Edrivers/gpu/drm/drm_stub.c
</sect2>
<sect2>
<title>Driver Load</title>