<para>
[Insert diagram of typical DRM stack here]
</para>
+ <sect1>
+ <title>Style Guidelines</title>
+ <para>
+ For consistency this documentation uses American English. Abbreviations
+ are written as all-uppercase, for example: DRM, KMS, IOCTL, CRTC, and so
+ on. To aid in reading, documentations make full use of the markup
+ characters kerneldoc provides: @parameter for function parameters, @member
+ for structure members, &structure to reference structures and
+ function() for functions. These all get automatically hyperlinked if
+ kerneldoc for the referenced objects exists. When referencing entries in
+ function vtables please use ->vfunc(). Note that kerneldoc does
+ not support referencing struct members directly, so please add a reference
+ to the vtable struct somewhere in the same paragraph or at least section.
+ </para>
+ <para>
+ Except in special situations (to separate locked from unlocked variants)
+ locking requirements for functions aren't documented in the kerneldoc.
+ Instead locking should be check at runtime using e.g.
+ <code>WARN_ON(!mutex_is_locked(...));</code>. Since it's much easier to
+ ignore documentation than runtime noise this provides more value. And on
+ top of that runtime checks do need to be updated when the locking rules
+ change, increasing the chances that they're correct. Within the
+ documentation the locking rules should be explained in the relevant
+ structures: Either in the comment for the lock explaining what it
+ protects, or data fields need a note about which lock protects them, or
+ both.
+ </para>
+ <para>
+ Functions which have a non-<code>void</code> return value should have a
+ section called "Returns" explaining the expected return values in
+ different cases and their meanings. Currently there's no consensus whether
+ that section name should be all upper-case or not, and whether it should
+ end in a colon or not. Go with the file-local style. Other common section
+ names are "Notes" with information for dangerous or tricky corner cases,
+ and "FIXME" where the interface could be cleaned up.
+ </para>
+ </sect1>
</chapter>
<!-- Internals -->
<sect2>
<title>Atomic Mode Setting Function Reference</title>
!Edrivers/gpu/drm/drm_atomic.c
+!Idrivers/gpu/drm/drm_atomic.c
</sect2>
<sect2>
- <title>Frame Buffer Creation</title>
- <synopsis>struct drm_framebuffer *(*fb_create)(struct drm_device *dev,
- struct drm_file *file_priv,
- struct drm_mode_fb_cmd2 *mode_cmd);</synopsis>
+ <title>Frame Buffer Abstraction</title>
<para>
Frame buffers are abstract memory objects that provide a source of
pixels to scanout to a CRTC. Applications explicitly request the
handles, e.g. vmwgfx directly exposes special TTM handles to userspace
and so expects TTM handles in the create ioctl and not GEM handles.
</para>
- <para>
- Drivers must first validate the requested frame buffer parameters passed
- through the mode_cmd argument. In particular this is where invalid
- sizes, pixel formats or pitches can be caught.
- </para>
- <para>
- If the parameters are deemed valid, drivers then create, initialize and
- return an instance of struct <structname>drm_framebuffer</structname>.
- If desired the instance can be embedded in a larger driver-specific
- structure. Drivers must fill its <structfield>width</structfield>,
- <structfield>height</structfield>, <structfield>pitches</structfield>,
- <structfield>offsets</structfield>, <structfield>depth</structfield>,
- <structfield>bits_per_pixel</structfield> and
- <structfield>pixel_format</structfield> fields from the values passed
- through the <parameter>drm_mode_fb_cmd2</parameter> argument. They
- should call the <function>drm_helper_mode_fill_fb_struct</function>
- helper function to do so.
- </para>
-
- <para>
- The initialization of the new framebuffer instance is finalized with a
- call to <function>drm_framebuffer_init</function> which takes a pointer
- to DRM frame buffer operations (struct
- <structname>drm_framebuffer_funcs</structname>). Note that this function
- publishes the framebuffer and so from this point on it can be accessed
- concurrently from other threads. Hence it must be the last step in the
- driver's framebuffer initialization sequence. Frame buffer operations
- are
- <itemizedlist>
- <listitem>
- <synopsis>int (*create_handle)(struct drm_framebuffer *fb,
- struct drm_file *file_priv, unsigned int *handle);</synopsis>
- <para>
- Create a handle to the frame buffer underlying memory object. If
- the frame buffer uses a multi-plane format, the handle will
- reference the memory object associated with the first plane.
- </para>
- <para>
- Drivers call <function>drm_gem_handle_create</function> to create
- the handle.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*destroy)(struct drm_framebuffer *framebuffer);</synopsis>
- <para>
- Destroy the frame buffer object and frees all associated
- resources. Drivers must call
- <function>drm_framebuffer_cleanup</function> to free resources
- allocated by the DRM core for the frame buffer object, and must
- make sure to unreference all memory objects associated with the
- frame buffer. Handles created by the
- <methodname>create_handle</methodname> operation are released by
- the DRM core.
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*dirty)(struct drm_framebuffer *framebuffer,
- struct drm_file *file_priv, unsigned flags, unsigned color,
- struct drm_clip_rect *clips, unsigned num_clips);</synopsis>
- <para>
- This optional operation notifies the driver that a region of the
- frame buffer has changed in response to a DRM_IOCTL_MODE_DIRTYFB
- ioctl call.
- </para>
- </listitem>
- </itemizedlist>
- </para>
<para>
The lifetime of a drm framebuffer is controlled with a reference count,
drivers can grab additional references with
pointer to CRTC functions.
</para>
</sect3>
- <sect3 id="drm-kms-crtcops">
- <title>CRTC Operations</title>
- <sect4>
- <title>Set Configuration</title>
- <synopsis>int (*set_config)(struct drm_mode_set *set);</synopsis>
- <para>
- Apply a new CRTC configuration to the device. The configuration
- specifies a CRTC, a frame buffer to scan out from, a (x,y) position in
- the frame buffer, a display mode and an array of connectors to drive
- with the CRTC if possible.
- </para>
- <para>
- If the frame buffer specified in the configuration is NULL, the driver
- must detach all encoders connected to the CRTC and all connectors
- attached to those encoders and disable them.
- </para>
- <para>
- This operation is called with the mode config lock held.
- </para>
- <note><para>
- Note that the drm core has no notion of restoring the mode setting
- state after resume, since all resume handling is in the full
- responsibility of the driver. The common mode setting helper library
- though provides a helper which can be used for this:
- <function>drm_helper_resume_force_mode</function>.
- </para></note>
- </sect4>
- <sect4>
- <title>Page Flipping</title>
- <synopsis>int (*page_flip)(struct drm_crtc *crtc, struct drm_framebuffer *fb,
- struct drm_pending_vblank_event *event);</synopsis>
- <para>
- Schedule a page flip to the given frame buffer for the CRTC. This
- operation is called with the mode config mutex held.
- </para>
- <para>
- Page flipping is a synchronization mechanism that replaces the frame
- buffer being scanned out by the CRTC with a new frame buffer during
- vertical blanking, avoiding tearing. When an application requests a page
- flip the DRM core verifies that the new frame buffer is large enough to
- be scanned out by the CRTC in the currently configured mode and then
- calls the CRTC <methodname>page_flip</methodname> operation with a
- pointer to the new frame buffer.
- </para>
- <para>
- The <methodname>page_flip</methodname> operation schedules a page flip.
- Once any pending rendering targeting the new frame buffer has
- completed, the CRTC will be reprogrammed to display that frame buffer
- after the next vertical refresh. The operation must return immediately
- without waiting for rendering or page flip to complete and must block
- any new rendering to the frame buffer until the page flip completes.
- </para>
- <para>
- If a page flip can be successfully scheduled the driver must set the
- <code>drm_crtc->fb</code> field to the new framebuffer pointed to
- by <code>fb</code>. This is important so that the reference counting
- on framebuffers stays balanced.
- </para>
- <para>
- If a page flip is already pending, the
- <methodname>page_flip</methodname> operation must return
- -<errorname>EBUSY</errorname>.
- </para>
- <para>
- To synchronize page flip to vertical blanking the driver will likely
- need to enable vertical blanking interrupts. It should call
- <function>drm_vblank_get</function> for that purpose, and call
- <function>drm_vblank_put</function> after the page flip completes.
- </para>
- <para>
- If the application has requested to be notified when page flip completes
- the <methodname>page_flip</methodname> operation will be called with a
- non-NULL <parameter>event</parameter> argument pointing to a
- <structname>drm_pending_vblank_event</structname> instance. Upon page
- flip completion the driver must call <methodname>drm_send_vblank_event</methodname>
- to fill in the event and send to wake up any waiting processes.
- This can be performed with
- <programlisting><![CDATA[
- spin_lock_irqsave(&dev->event_lock, flags);
- ...
- drm_send_vblank_event(dev, pipe, event);
- spin_unlock_irqrestore(&dev->event_lock, flags);
- ]]></programlisting>
- </para>
- <note><para>
- FIXME: Could drivers that don't need to wait for rendering to complete
- just add the event to <literal>dev->vblank_event_list</literal> and
- let the DRM core handle everything, as for "normal" vertical blanking
- events?
- </para></note>
- <para>
- While waiting for the page flip to complete, the
- <literal>event->base.link</literal> list head can be used freely by
- the driver to store the pending event in a driver-specific list.
- </para>
- <para>
- If the file handle is closed before the event is signaled, drivers must
- take care to destroy the event in their
- <methodname>preclose</methodname> operation (and, if needed, call
- <function>drm_vblank_put</function>).
- </para>
- </sect4>
- <sect4>
- <title>Miscellaneous</title>
- <itemizedlist>
- <listitem>
- <synopsis>void (*set_property)(struct drm_crtc *crtc,
- struct drm_property *property, uint64_t value);</synopsis>
- <para>
- Set the value of the given CRTC property to
- <parameter>value</parameter>. See <xref linkend="drm-kms-properties"/>
- for more information about properties.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
- uint32_t start, uint32_t size);</synopsis>
- <para>
- Apply a gamma table to the device. The operation is optional.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*destroy)(struct drm_crtc *crtc);</synopsis>
- <para>
- Destroy the CRTC when not needed anymore. See
- <xref linkend="drm-kms-init"/>.
- </para>
- </listitem>
- </itemizedlist>
- </sect4>
- </sect3>
</sect2>
<sect2>
<title>Planes (struct <structname>drm_plane</structname>)</title>
<listitem>
DRM_PLANE_TYPE_PRIMARY represents a "main" plane for a CRTC. Primary
planes are the planes operated upon by CRTC modesetting and flipping
- operations described in <xref linkend="drm-kms-crtcops"/>.
+ operations described in the page_flip hook in <structname>drm_crtc_funcs</structname>.
</listitem>
<listitem>
DRM_PLANE_TYPE_CURSOR represents a "cursor" plane for a CRTC. Cursor
primary plane with standard capabilities.
</para>
</sect3>
- <sect3>
- <title>Plane Operations</title>
- <itemizedlist>
- <listitem>
- <synopsis>int (*update_plane)(struct drm_plane *plane, struct drm_crtc *crtc,
- struct drm_framebuffer *fb, int crtc_x, int crtc_y,
- unsigned int crtc_w, unsigned int crtc_h,
- uint32_t src_x, uint32_t src_y,
- uint32_t src_w, uint32_t src_h);</synopsis>
- <para>
- Enable and configure the plane to use the given CRTC and frame buffer.
- </para>
- <para>
- The source rectangle in frame buffer memory coordinates is given by
- the <parameter>src_x</parameter>, <parameter>src_y</parameter>,
- <parameter>src_w</parameter> and <parameter>src_h</parameter>
- parameters (as 16.16 fixed point values). Devices that don't support
- subpixel plane coordinates can ignore the fractional part.
- </para>
- <para>
- The destination rectangle in CRTC coordinates is given by the
- <parameter>crtc_x</parameter>, <parameter>crtc_y</parameter>,
- <parameter>crtc_w</parameter> and <parameter>crtc_h</parameter>
- parameters (as integer values). Devices scale the source rectangle to
- the destination rectangle. If scaling is not supported, and the source
- rectangle size doesn't match the destination rectangle size, the
- driver must return a -<errorname>EINVAL</errorname> error.
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*disable_plane)(struct drm_plane *plane);</synopsis>
- <para>
- Disable the plane. The DRM core calls this method in response to a
- DRM_IOCTL_MODE_SETPLANE ioctl call with the frame buffer ID set to 0.
- Disabled planes must not be processed by the CRTC.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*destroy)(struct drm_plane *plane);</synopsis>
- <para>
- Destroy the plane when not needed anymore. See
- <xref linkend="drm-kms-init"/>.
- </para>
- </listitem>
- </itemizedlist>
- </sect3>
</sect2>
<sect2>
<title>Encoders (struct <structname>drm_encoder</structname>)</title>
encoders they want to use to a CRTC.
</para>
</sect3>
- <sect3>
- <title>Encoder Operations</title>
- <itemizedlist>
- <listitem>
- <synopsis>void (*destroy)(struct drm_encoder *encoder);</synopsis>
- <para>
- Called to destroy the encoder when not needed anymore. See
- <xref linkend="drm-kms-init"/>.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*set_property)(struct drm_plane *plane,
- struct drm_property *property, uint64_t value);</synopsis>
- <para>
- Set the value of the given plane property to
- <parameter>value</parameter>. See <xref linkend="drm-kms-properties"/>
- for more information about properties.
- </para>
- </listitem>
- </itemizedlist>
- </sect3>
</sect2>
<sect2>
<title>Connectors (struct <structname>drm_connector</structname>)</title>
connector_status_unknown.
</para>
</sect4>
- <sect4>
- <title>Miscellaneous</title>
- <itemizedlist>
- <listitem>
- <synopsis>void (*set_property)(struct drm_connector *connector,
- struct drm_property *property, uint64_t value);</synopsis>
- <para>
- Set the value of the given connector property to
- <parameter>value</parameter>. See <xref linkend="drm-kms-properties"/>
- for more information about properties.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*destroy)(struct drm_connector *connector);</synopsis>
- <para>
- Destroy the connector when not needed anymore. See
- <xref linkend="drm-kms-init"/>.
- </para>
- </listitem>
- </itemizedlist>
- </sect4>
</sect3>
</sect2>
<sect2>
To use it, a driver must provide bottom functions for all of the three KMS
entities.
</para>
- <sect2>
- <title>Helper Functions</title>
- <itemizedlist>
- <listitem>
- <synopsis>int drm_crtc_helper_set_config(struct drm_mode_set *set);</synopsis>
- <para>
- The <function>drm_crtc_helper_set_config</function> helper function
- is a CRTC <methodname>set_config</methodname> implementation. It
- first tries to locate the best encoder for each connector by calling
- the connector <methodname>best_encoder</methodname> helper
- operation.
- </para>
- <para>
- After locating the appropriate encoders, the helper function will
- call the <methodname>mode_fixup</methodname> encoder and CRTC helper
- operations to adjust the requested mode, or reject it completely in
- which case an error will be returned to the application. If the new
- configuration after mode adjustment is identical to the current
- configuration the helper function will return without performing any
- other operation.
- </para>
- <para>
- If the adjusted mode is identical to the current mode but changes to
- the frame buffer need to be applied, the
- <function>drm_crtc_helper_set_config</function> function will call
- the CRTC <methodname>mode_set_base</methodname> helper operation. If
- the adjusted mode differs from the current mode, or if the
- <methodname>mode_set_base</methodname> helper operation is not
- provided, the helper function performs a full mode set sequence by
- calling the <methodname>prepare</methodname>,
- <methodname>mode_set</methodname> and
- <methodname>commit</methodname> CRTC and encoder helper operations,
- in that order.
- </para>
- </listitem>
- <listitem>
- <synopsis>void drm_helper_connector_dpms(struct drm_connector *connector, int mode);</synopsis>
- <para>
- The <function>drm_helper_connector_dpms</function> helper function
- is a connector <methodname>dpms</methodname> implementation that
- tracks power state of connectors. To use the function, drivers must
- provide <methodname>dpms</methodname> helper operations for CRTCs
- and encoders to apply the DPMS state to the device.
- </para>
- <para>
- The mid-layer doesn't track the power state of CRTCs and encoders.
- The <methodname>dpms</methodname> helper operations can thus be
- called with a mode identical to the currently active mode.
- </para>
- </listitem>
- <listitem>
- <synopsis>int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
- uint32_t maxX, uint32_t maxY);</synopsis>
- <para>
- The <function>drm_helper_probe_single_connector_modes</function> helper
- function is a connector <methodname>fill_modes</methodname>
- implementation that updates the connection status for the connector
- and then retrieves a list of modes by calling the connector
- <methodname>get_modes</methodname> helper operation.
- </para>
- <para>
- If the helper operation returns no mode, and if the connector status
- is connector_status_connected, standard VESA DMT modes up to
- 1024x768 are automatically added to the modes list by a call to
- <function>drm_add_modes_noedid</function>.
- </para>
- <para>
- The function then filters out modes larger than
- <parameter>max_width</parameter> and <parameter>max_height</parameter>
- if specified. It finally calls the optional connector
- <methodname>mode_valid</methodname> helper operation for each mode in
- the probed list to check whether the mode is valid for the connector.
- </para>
- </listitem>
- </itemizedlist>
- </sect2>
- <sect2>
- <title>CRTC Helper Operations</title>
- <itemizedlist>
- <listitem id="drm-helper-crtc-mode-fixup">
- <synopsis>bool (*mode_fixup)(struct drm_crtc *crtc,
- const struct drm_display_mode *mode,
- struct drm_display_mode *adjusted_mode);</synopsis>
- <para>
- Let CRTCs adjust the requested mode or reject it completely. This
- operation returns true if the mode is accepted (possibly after being
- adjusted) or false if it is rejected.
- </para>
- <para>
- The <methodname>mode_fixup</methodname> operation should reject the
- mode if it can't reasonably use it. The definition of "reasonable"
- is currently fuzzy in this context. One possible behaviour would be
- to set the adjusted mode to the panel timings when a fixed-mode
- panel is used with hardware capable of scaling. Another behaviour
- would be to accept any input mode and adjust it to the closest mode
- supported by the hardware (FIXME: This needs to be clarified).
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
- struct drm_framebuffer *old_fb)</synopsis>
- <para>
- Move the CRTC on the current frame buffer (stored in
- <literal>crtc->fb</literal>) to position (x,y). Any of the frame
- buffer, x position or y position may have been modified.
- </para>
- <para>
- This helper operation is optional. If not provided, the
- <function>drm_crtc_helper_set_config</function> function will fall
- back to the <methodname>mode_set</methodname> helper operation.
- </para>
- <note><para>
- FIXME: Why are x and y passed as arguments, as they can be accessed
- through <literal>crtc->x</literal> and
- <literal>crtc->y</literal>?
- </para></note>
- </listitem>
- <listitem>
- <synopsis>void (*prepare)(struct drm_crtc *crtc);</synopsis>
- <para>
- Prepare the CRTC for mode setting. This operation is called after
- validating the requested mode. Drivers use it to perform
- device-specific operations required before setting the new mode.
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
- struct drm_display_mode *adjusted_mode, int x, int y,
- struct drm_framebuffer *old_fb);</synopsis>
- <para>
- Set a new mode, position and frame buffer. Depending on the device
- requirements, the mode can be stored internally by the driver and
- applied in the <methodname>commit</methodname> operation, or
- programmed to the hardware immediately.
- </para>
- <para>
- The <methodname>mode_set</methodname> operation returns 0 on success
- or a negative error code if an error occurs.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*commit)(struct drm_crtc *crtc);</synopsis>
- <para>
- Commit a mode. This operation is called after setting the new mode.
- Upon return the device must use the new mode and be fully
- operational.
- </para>
- </listitem>
- </itemizedlist>
- </sect2>
- <sect2>
- <title>Encoder Helper Operations</title>
- <itemizedlist>
- <listitem>
- <synopsis>bool (*mode_fixup)(struct drm_encoder *encoder,
- const struct drm_display_mode *mode,
- struct drm_display_mode *adjusted_mode);</synopsis>
- <para>
- Let encoders adjust the requested mode or reject it completely. This
- operation returns true if the mode is accepted (possibly after being
- adjusted) or false if it is rejected. See the
- <link linkend="drm-helper-crtc-mode-fixup">mode_fixup CRTC helper
- operation</link> for an explanation of the allowed adjustments.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*prepare)(struct drm_encoder *encoder);</synopsis>
- <para>
- Prepare the encoder for mode setting. This operation is called after
- validating the requested mode. Drivers use it to perform
- device-specific operations required before setting the new mode.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*mode_set)(struct drm_encoder *encoder,
- struct drm_display_mode *mode,
- struct drm_display_mode *adjusted_mode);</synopsis>
- <para>
- Set a new mode. Depending on the device requirements, the mode can
- be stored internally by the driver and applied in the
- <methodname>commit</methodname> operation, or programmed to the
- hardware immediately.
- </para>
- </listitem>
- <listitem>
- <synopsis>void (*commit)(struct drm_encoder *encoder);</synopsis>
- <para>
- Commit a mode. This operation is called after setting the new mode.
- Upon return the device must use the new mode and be fully
- operational.
- </para>
- </listitem>
- </itemizedlist>
- </sect2>
- <sect2>
- <title>Connector Helper Operations</title>
- <itemizedlist>
- <listitem>
- <synopsis>struct drm_encoder *(*best_encoder)(struct drm_connector *connector);</synopsis>
- <para>
- Return a pointer to the best encoder for the connecter. Device that
- map connectors to encoders 1:1 simply return the pointer to the
- associated encoder. This operation is mandatory.
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*get_modes)(struct drm_connector *connector);</synopsis>
- <para>
- Fill the connector's <structfield>probed_modes</structfield> list
- by parsing EDID data with <function>drm_add_edid_modes</function>,
- adding standard VESA DMT modes with <function>drm_add_modes_noedid</function>,
- or calling <function>drm_mode_probed_add</function> directly for every
- supported mode and return the number of modes it has detected. This
- operation is mandatory.
- </para>
- <para>
- Note that the caller function will automatically add standard VESA
- DMT modes up to 1024x768 if the <methodname>get_modes</methodname>
- helper operation returns no mode and if the connector status is
- connector_status_connected. There is no need to call
- <function>drm_add_edid_modes</function> manually in that case.
- </para>
- <para>
- When adding modes manually the driver creates each mode with a call to
- <function>drm_mode_create</function> and must fill the following fields.
- <itemizedlist>
- <listitem>
- <synopsis>__u32 type;</synopsis>
- <para>
- Mode type bitmask, a combination of
- <variablelist>
- <varlistentry>
- <term>DRM_MODE_TYPE_BUILTIN</term>
- <listitem><para>not used?</para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_CLOCK_C</term>
- <listitem><para>not used?</para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_CRTC_C</term>
- <listitem><para>not used?</para></listitem>
- </varlistentry>
- <varlistentry>
- <term>
- DRM_MODE_TYPE_PREFERRED - The preferred mode for the connector
- </term>
- <listitem>
- <para>not used?</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_DEFAULT</term>
- <listitem><para>not used?</para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_USERDEF</term>
- <listitem><para>not used?</para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_DRIVER</term>
- <listitem>
- <para>
- The mode has been created by the driver (as opposed to
- to user-created modes).
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- Drivers must set the DRM_MODE_TYPE_DRIVER bit for all modes they
- create, and set the DRM_MODE_TYPE_PREFERRED bit for the preferred
- mode.
- </para>
- </listitem>
- <listitem>
- <synopsis>__u32 clock;</synopsis>
- <para>Pixel clock frequency in kHz unit</para>
- </listitem>
- <listitem>
- <synopsis>__u16 hdisplay, hsync_start, hsync_end, htotal;
- __u16 vdisplay, vsync_start, vsync_end, vtotal;</synopsis>
- <para>Horizontal and vertical timing information</para>
- <screen><![CDATA[
- Active Front Sync Back
- Region Porch Porch
- <-----------------------><----------------><-------------><-------------->
-
- //////////////////////|
- ////////////////////// |
- ////////////////////// |.................. ................
- _______________
-
- <----- [hv]display ----->
- <------------- [hv]sync_start ------------>
- <--------------------- [hv]sync_end --------------------->
- <-------------------------------- [hv]total ----------------------------->
-]]></screen>
- </listitem>
- <listitem>
- <synopsis>__u16 hskew;
- __u16 vscan;</synopsis>
- <para>Unknown</para>
- </listitem>
- <listitem>
- <synopsis>__u32 flags;</synopsis>
- <para>
- Mode flags, a combination of
- <variablelist>
- <varlistentry>
- <term>DRM_MODE_FLAG_PHSYNC</term>
- <listitem><para>
- Horizontal sync is active high
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NHSYNC</term>
- <listitem><para>
- Horizontal sync is active low
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PVSYNC</term>
- <listitem><para>
- Vertical sync is active high
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NVSYNC</term>
- <listitem><para>
- Vertical sync is active low
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_INTERLACE</term>
- <listitem><para>
- Mode is interlaced
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_DBLSCAN</term>
- <listitem><para>
- Mode uses doublescan
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_CSYNC</term>
- <listitem><para>
- Mode uses composite sync
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PCSYNC</term>
- <listitem><para>
- Composite sync is active high
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NCSYNC</term>
- <listitem><para>
- Composite sync is active low
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_HSKEW</term>
- <listitem><para>
- hskew provided (not used?)
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_BCAST</term>
- <listitem><para>
- not used?
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PIXMUX</term>
- <listitem><para>
- not used?
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_DBLCLK</term>
- <listitem><para>
- not used?
- </para></listitem>
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_CLKDIV2</term>
- <listitem><para>
- ?
- </para></listitem>
- </varlistentry>
- </variablelist>
- </para>
- <para>
- Note that modes marked with the INTERLACE or DBLSCAN flags will be
- filtered out by
- <function>drm_helper_probe_single_connector_modes</function> if
- the connector's <structfield>interlace_allowed</structfield> or
- <structfield>doublescan_allowed</structfield> field is set to 0.
- </para>
- </listitem>
- <listitem>
- <synopsis>char name[DRM_DISPLAY_MODE_LEN];</synopsis>
- <para>
- Mode name. The driver must call
- <function>drm_mode_set_name</function> to fill the mode name from
- <structfield>hdisplay</structfield>,
- <structfield>vdisplay</structfield> and interlace flag after
- filling the corresponding fields.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- <para>
- The <structfield>vrefresh</structfield> value is computed by
- <function>drm_helper_probe_single_connector_modes</function>.
- </para>
- <para>
- When parsing EDID data, <function>drm_add_edid_modes</function> fills the
- connector <structfield>display_info</structfield>
- <structfield>width_mm</structfield> and
- <structfield>height_mm</structfield> fields. When creating modes
- manually the <methodname>get_modes</methodname> helper operation must
- set the <structfield>display_info</structfield>
- <structfield>width_mm</structfield> and
- <structfield>height_mm</structfield> fields if they haven't been set
- already (for instance at initialization time when a fixed-size panel is
- attached to the connector). The mode <structfield>width_mm</structfield>
- and <structfield>height_mm</structfield> fields are only used internally
- during EDID parsing and should not be set when creating modes manually.
- </para>
- </listitem>
- <listitem>
- <synopsis>int (*mode_valid)(struct drm_connector *connector,
- struct drm_display_mode *mode);</synopsis>
- <para>
- Verify whether a mode is valid for the connector. Return MODE_OK for
- supported modes and one of the enum drm_mode_status values (MODE_*)
- for unsupported modes. This operation is optional.
- </para>
- <para>
- As the mode rejection reason is currently not used beside for
- immediately removing the unsupported mode, an implementation can
- return MODE_BAD regardless of the exact reason why the mode is not
- valid.
- </para>
- <note><para>
- Note that the <methodname>mode_valid</methodname> helper operation is
- only called for modes detected by the device, and
- <emphasis>not</emphasis> for modes set by the user through the CRTC
- <methodname>set_config</methodname> operation.
- </para></note>
- </listitem>
- </itemizedlist>
- </sect2>
<sect2>
<title>Atomic Modeset Helper Functions Reference</title>
<sect3>
!Edrivers/gpu/drm/drm_atomic_helper.c
</sect2>
<sect2>
- <title>Modeset Helper Functions Reference</title>
-!Iinclude/drm/drm_crtc_helper.h
+ <title>Modeset Helper Reference for Common Vtables</title>
+!Iinclude/drm/drm_modeset_helper_vtables.h
+!Pinclude/drm/drm_modeset_helper_vtables.h overview
+ </sect2>
+ <sect2>
+ <title>Legacy CRTC/Modeset Helper Functions Reference</title>
!Edrivers/gpu/drm/drm_crtc_helper.c
!Pdrivers/gpu/drm/drm_crtc_helper.c overview
</sect2>
<sect2>
<title>DPIO</title>
!Pdrivers/gpu/drm/i915/i915_reg.h DPIO
- <table id="dpiox2">
- <title>Dual channel PHY (VLV/CHV/BXT)</title>
- <tgroup cols="8">
- <colspec colname="c0" />
- <colspec colname="c1" />
- <colspec colname="c2" />
- <colspec colname="c3" />
- <colspec colname="c4" />
- <colspec colname="c5" />
- <colspec colname="c6" />
- <colspec colname="c7" />
- <spanspec spanname="ch0" namest="c0" nameend="c3" />
- <spanspec spanname="ch1" namest="c4" nameend="c7" />
- <spanspec spanname="ch0pcs01" namest="c0" nameend="c1" />
- <spanspec spanname="ch0pcs23" namest="c2" nameend="c3" />
- <spanspec spanname="ch1pcs01" namest="c4" nameend="c5" />
- <spanspec spanname="ch1pcs23" namest="c6" nameend="c7" />
- <thead>
- <row>
- <entry spanname="ch0">CH0</entry>
- <entry spanname="ch1">CH1</entry>
- </row>
- </thead>
- <tbody valign="top" align="center">
- <row>
- <entry spanname="ch0">CMN/PLL/REF</entry>
- <entry spanname="ch1">CMN/PLL/REF</entry>
- </row>
- <row>
- <entry spanname="ch0pcs01">PCS01</entry>
- <entry spanname="ch0pcs23">PCS23</entry>
- <entry spanname="ch1pcs01">PCS01</entry>
- <entry spanname="ch1pcs23">PCS23</entry>
- </row>
- <row>
- <entry>TX0</entry>
- <entry>TX1</entry>
- <entry>TX2</entry>
- <entry>TX3</entry>
- <entry>TX0</entry>
- <entry>TX1</entry>
- <entry>TX2</entry>
- <entry>TX3</entry>
- </row>
- <row>
- <entry spanname="ch0">DDI0</entry>
- <entry spanname="ch1">DDI1</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- <table id="dpiox1">
- <title>Single channel PHY (CHV/BXT)</title>
- <tgroup cols="4">
- <colspec colname="c0" />
- <colspec colname="c1" />
- <colspec colname="c2" />
- <colspec colname="c3" />
- <spanspec spanname="ch0" namest="c0" nameend="c3" />
- <spanspec spanname="ch0pcs01" namest="c0" nameend="c1" />
- <spanspec spanname="ch0pcs23" namest="c2" nameend="c3" />
- <thead>
- <row>
- <entry spanname="ch0">CH0</entry>
- </row>
- </thead>
- <tbody valign="top" align="center">
- <row>
- <entry spanname="ch0">CMN/PLL/REF</entry>
- </row>
- <row>
- <entry spanname="ch0pcs01">PCS01</entry>
- <entry spanname="ch0pcs23">PCS23</entry>
- </row>
- <row>
- <entry>TX0</entry>
- <entry>TX1</entry>
- <entry>TX2</entry>
- <entry>TX3</entry>
- </row>
- <row>
- <entry spanname="ch0">DDI2</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
</sect2>
<sect2>
<chapter id="modes_of_use">
<title>Modes of Use</title>
- <sect1>
- <title>Manual switching and manual power control</title>
+ <sect1>
+ <title>Manual switching and manual power control</title>
!Pdrivers/gpu/vga/vga_switcheroo.c Manual switching and manual power control
- </sect1>
- <sect1>
- <title>Driver power control</title>
+ </sect1>
+ <sect1>
+ <title>Driver power control</title>
!Pdrivers/gpu/vga/vga_switcheroo.c Driver power control
- </sect1>
+ </sect1>
</chapter>
- <chapter id="pubfunctions">
- <title>Public functions</title>
+ <chapter id="api">
+ <title>API</title>
+ <sect1>
+ <title>Public functions</title>
!Edrivers/gpu/vga/vga_switcheroo.c
- </chapter>
-
- <chapter id="pubstructures">
- <title>Public structures</title>
+ </sect1>
+ <sect1>
+ <title>Public structures</title>
!Finclude/linux/vga_switcheroo.h vga_switcheroo_handler
!Finclude/linux/vga_switcheroo.h vga_switcheroo_client_ops
- </chapter>
-
- <chapter id="pubconstants">
- <title>Public constants</title>
+ </sect1>
+ <sect1>
+ <title>Public constants</title>
!Finclude/linux/vga_switcheroo.h vga_switcheroo_client_id
!Finclude/linux/vga_switcheroo.h vga_switcheroo_state
- </chapter>
-
- <chapter id="privstructures">
- <title>Private structures</title>
+ </sect1>
+ <sect1>
+ <title>Private structures</title>
!Fdrivers/gpu/vga/vga_switcheroo.c vgasr_priv
!Fdrivers/gpu/vga/vga_switcheroo.c vga_switcheroo_client
+ </sect1>
+ </chapter>
+
+ <chapter id="handlers">
+ <title>Handlers</title>
+ <sect1>
+ <title>apple-gmux Handler</title>
+!Pdrivers/platform/x86/apple-gmux.c Overview
+!Pdrivers/platform/x86/apple-gmux.c Interrupt
+ <sect2>
+ <title>Graphics mux</title>
+!Pdrivers/platform/x86/apple-gmux.c Graphics mux
+ </sect2>
+ <sect2>
+ <title>Power control</title>
+!Pdrivers/platform/x86/apple-gmux.c Power control
+ </sect2>
+ <sect2>
+ <title>Backlight control</title>
+!Pdrivers/platform/x86/apple-gmux.c Backlight control
+ </sect2>
+ </sect1>
</chapter>
!Cdrivers/gpu/vga/vga_switcheroo.c
!Cinclude/linux/vga_switcheroo.h
+!Cdrivers/platform/x86/apple-gmux.c
</part>
</book>
projects / linux-drm-fsl-dcu.git / blobdiff