- <para>
- The <methodname>load</methodname> method is the driver and device
- initialization entry point. The method is responsible for allocating and
- initializing driver private data, performing resource allocation and
- mapping (e.g. acquiring
- clocks, mapping registers or allocating command buffers), initializing
- the memory manager (<xref linkend="drm-memory-management"/>), installing
- the IRQ handler (<xref linkend="drm-irq-registration"/>), setting up
- vertical blanking handling (<xref linkend="drm-vertical-blank"/>), mode
- setting (<xref linkend="drm-mode-setting"/>) and initial output
- configuration (<xref linkend="drm-kms-init"/>).
- </para>
- <note><para>
- If compatibility is a concern (e.g. with drivers converted over from
- User Mode Setting to Kernel Mode Setting), care must be taken to prevent
- device initialization and control that is incompatible with currently
- active userspace drivers. For instance, if user level mode setting
- drivers are in use, it would be problematic to perform output discovery
- & configuration at load time. Likewise, if user-level drivers
- unaware of memory management are in use, memory management and command
- buffer setup may need to be omitted. These requirements are
- driver-specific, and care needs to be taken to keep both old and new
- applications and libraries working.
- </para></note>
- <synopsis>int (*load) (struct drm_device *, unsigned long flags);</synopsis>
- <para>
- The method takes two arguments, a pointer to the newly created
- <structname>drm_device</structname> and flags. The flags are used to
- pass the <structfield>driver_data</structfield> field of the device id
- corresponding to the device passed to <function>drm_*_init()</function>.
- Only PCI devices currently use this, USB and platform DRM drivers have
- their <methodname>load</methodname> method called with flags to 0.
- </para>
- <sect3>
- <title>Driver Private Data</title>
- <para>
- The driver private hangs off the main
- <structname>drm_device</structname> structure and can be used for
- tracking various device-specific bits of information, like register
- offsets, command buffer status, register state for suspend/resume, etc.
- At load time, a driver may simply allocate one and set
- <structname>drm_device</structname>.<structfield>dev_priv</structfield>
- appropriately; it should be freed and
- <structname>drm_device</structname>.<structfield>dev_priv</structfield>
- set to NULL when the driver is unloaded.
- </para>
- </sect3>