[PATCH v3 3/4] drm: Document how to register devices without struct drm_bus

[Daniel Vetter]

On Thu, May 22, 2014 at 12:21:23PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> 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.
> 
> Signed-off-by: Thierry Reding <treding at nvidia.com>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> Changes in v3:
> - replace drm_dev_put() recommendation by explicit drm_dev_unregister()
>   followed by drm_dev_unref()
> - use !E in DocBook to insert kernel-doc for all exported symbols
> 
>  Documentation/DocBook/drm.tmpl | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
> index 438edcd566b5..09f8788fec3f 100644
> --- a/Documentation/DocBook/drm.tmpl
> +++ b/Documentation/DocBook/drm.tmpl
> @@ -142,6 +142,12 @@
>        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
>        pointers to methods that the DRM core will call to implement the DRM API.
> @@ -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>
> -- 
> 1.9.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch