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Commit b528ae71 authored by Thierry Reding's avatar Thierry Reding
Browse files

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: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent c6a1af8a

Documentation/DocBook/drm.tmpl

+26 −0
Original line number Diff line number Diff line
@@ -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>