[Intel-gfx] [PATCH 02/20] drm/doc: Light drm-kms-helper.rst cleanup
Daniel Vetter
daniel.vetter at ffwll.ch
Tue Aug 9 13:41:13 UTC 2016
- Move the common vtable stuff to the top
- Move "Tile Group" to a more appropriate heading level
- Throw away the old intro for the crtc helpers (it's entirely stale,
e.g. helpers have become modular years ago), and replace it with a
general intro about the motivation behind helpers.
- Reorder helpers to group them together a bit better, and explain
that grouping in the intro.
- Make sure the introductory DOC section is always first.
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
Documentation/gpu/drm-kms-helpers.rst | 208 +++++++++++++++++-----------------
drivers/gpu/drm/drm_kms_helper.c | 66 +++++++++++
include/drm/drm_kms_helper.h | 30 +++++
3 files changed, 200 insertions(+), 104 deletions(-)
create mode 100644 drivers/gpu/drm/drm_kms_helper.c
create mode 100644 include/drm/drm_kms_helper.h
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 0b302fedf1af..23458252f198 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -2,38 +2,45 @@
Mode Setting Helper Functions
=============================
-The plane, CRTC, encoder and connector functions provided by the drivers
-implement the DRM API. They're called by the DRM core and ioctl handlers
-to handle device state changes and configuration request. As
-implementing those functions often requires logic not specific to
-drivers, mid-layer helper functions are available to avoid duplicating
-boilerplate code.
-
-The DRM core contains one mid-layer implementation. The mid-layer
-provides implementations of several plane, CRTC, encoder and connector
-functions (called from the top of the mid-layer) that pre-process
-requests and call lower-level functions provided by the driver (at the
-bottom of the mid-layer). For instance, the
-:c:func:`drm_crtc_helper_set_config()` function can be used to
-fill the :c:type:`struct drm_crtc_funcs <drm_crtc_funcs>`
-set_config field. When called, it will split the set_config operation
-in smaller, simpler operations and call the driver to handle them.
-
-To use the mid-layer, drivers call
-:c:func:`drm_crtc_helper_add()`,
-:c:func:`drm_encoder_helper_add()` and
-:c:func:`drm_connector_helper_add()` functions to install their
-mid-layer bottom operations handlers, and fill the :c:type:`struct
-drm_crtc_funcs <drm_crtc_funcs>`, :c:type:`struct
-drm_encoder_funcs <drm_encoder_funcs>` and :c:type:`struct
-drm_connector_funcs <drm_connector_funcs>` structures with
-pointers to the mid-layer top API functions. Installing the mid-layer
-bottom operation handlers is best done right after registering the
-corresponding KMS object.
-
-The mid-layer is not split between CRTC, encoder and connector
-operations. To use it, a driver must provide bottom functions for all of
-the three KMS entities.
+The DRM subsystem aims for a strong separation between core code and helper
+libraries. Core code takes care of general setup and teardown and decoding
+userspace requests to kernel internal objects. Everything else is handled by a
+large set of helper libraries, which can be combined freely to pick and choose
+for each driver what fits, and avoid shared code where special behaviour is
+needed.
+
+This distinction between core code and helpers is especially strong in the
+modesetting code, where there's a shared userspace ABI for all drivers. This is
+in contrast to the render side, where pretty much everything (with very few
+exceptions) can be considered optional helper code.
+
+There are a few areas these helpers can grouped into:
+
+* Helpers to implement modesetting. This important ones here are the atomic
+ helpers. Old drivers still often use the legacy CRTC helpers. They both share
+ the same set of common helper vtables. For really simple drivers (anything
+ that would have been a great fit in the deprecated fbdev subsystem) there's
+ also the simple display pipe helpers.
+
+* There's a big pile of helpers for handling outputs. Firs the generic bridge
+ helpers for handling encoder and transcoder IP blocks, and the panel helpers
+ for handling panel-related information and logic. Plus then a big set of
+ helpers for the various sink standards (DisplayPort, HDMI, MIPI DSI). Finally
+ there's also generic helpers for handling output probing, and for dealing with
+ EDIDs.
+
+* The last group of helpers concerns itself with the frontend side of a display
+ pipeline: Planes, handling rectangles for visibility checking and scissoring,
+ flip queues and assorted bits.
+
+Modeset Helper Reference for Common Vtables
+===========================================
+
+.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
+ :internal:
+
+.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
+ :doc: overview
Atomic Modeset Helper Functions Reference
=========================================
@@ -62,33 +69,27 @@ Atomic State Reset and Initialization
.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
:export:
-Modeset Helper Reference for Common Vtables
-===========================================
-
-.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
- :internal:
-
-.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
- :doc: overview
-
Legacy CRTC/Modeset Helper Functions Reference
==============================================
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
- :export:
+ :doc: overview
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
- :doc: overview
+ :export:
-Output Probing Helper Functions Reference
-=========================================
+Simple KMS Helper Reference
+===========================
-.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
- :doc: output probing helper overview
+.. kernel-doc:: include/drm/drm_simple_kms_helper.h
+ :internal:
-.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
:export:
+.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
+ :doc: overview
+
fbdev Helper Functions Reference
================================
@@ -110,6 +111,36 @@ Framebuffer CMA Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
:export:
+Bridges
+=======
+
+Overview
+--------
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :doc: overview
+
+Default bridge callback sequence
+--------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :doc: bridge callbacks
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :export:
+
+Panel Helper Reference
+======================
+
+.. kernel-doc:: include/drm/drm_panel.h
+ :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_panel.c
+ :export:
+
+.. kernel-doc:: drivers/gpu/drm/drm_panel.c
+ :doc: drm panel
+
Display Port Helper Functions Reference
=======================================
@@ -158,6 +189,15 @@ MIPI DSI Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
:export:
+Output Probing Helper Functions Reference
+=========================================
+
+.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+ :doc: output probing helper overview
+
+.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+ :export:
+
EDID Helper Functions Reference
===============================
@@ -176,18 +216,6 @@ Rectangle Utilities Reference
.. kernel-doc:: drivers/gpu/drm/drm_rect.c
:export:
-Flip-work Helper Reference
-==========================
-
-.. kernel-doc:: include/drm/drm_flip_work.h
- :doc: flip utils
-
-.. kernel-doc:: include/drm/drm_flip_work.h
- :internal:
-
-.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
- :export:
-
HDMI Infoframes Helper Reference
================================
@@ -202,59 +230,31 @@ libraries and hence is also included here.
.. kernel-doc:: drivers/video/hdmi.c
:export:
-Plane Helper Reference
-======================
-
-.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
- :export:
-
-.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
- :doc: overview
-
-Tile group
-----------
-
-.. kernel-doc:: drivers/gpu/drm/drm_crtc.c
- :doc: Tile group
-
-Bridges
-=======
-
-Overview
---------
-
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
- :doc: overview
+Flip-work Helper Reference
+==========================
-Default bridge callback sequence
---------------------------------
+.. kernel-doc:: include/drm/drm_flip_work.h
+ :doc: flip utils
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
- :doc: bridge callbacks
+.. kernel-doc:: include/drm/drm_flip_work.h
+ :internal:
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
:export:
-Panel Helper Reference
+Plane Helper Reference
======================
-.. kernel-doc:: include/drm/drm_panel.h
- :internal:
+.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
+ :doc: overview
-.. kernel-doc:: drivers/gpu/drm/drm_panel.c
+.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:export:
-.. kernel-doc:: drivers/gpu/drm/drm_panel.c
- :doc: drm panel
-
-Simple KMS Helper Reference
-===========================
-
-.. kernel-doc:: include/drm/drm_simple_kms_helper.h
- :internal:
+Tile group
+==========
-.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
- :export:
+# FIXME: This should probably be moved into a property documentation section
-.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
- :doc: overview
+.. kernel-doc:: drivers/gpu/drm/drm_crtc.c
+ :doc: Tile group
diff --git a/drivers/gpu/drm/drm_kms_helper.c b/drivers/gpu/drm/drm_kms_helper.c
new file mode 100644
index 000000000000..127f574d29a4
--- /dev/null
+++ b/drivers/gpu/drm/drm_kms_helper.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <drm/drm_kms_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_plane_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_edid.h>
+
+/**
+ * DOC: aux kms helpers
+ *
+ * This helper library contains various one-off functions which don't really fit
+ * anywhere else in the DRM modeset helper library.
+ */
+
+/**
+ * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
+ * connector list
+ * @dev: drm device to operate on
+ *
+ * Some userspace presumes that the first connected connector is the main
+ * display, where it's supposed to display e.g. the login screen. For
+ * laptops, this should be the main panel. Use this function to sort all
+ * (eDP/LVDS) panels to the front of the connector list, instead of
+ * painstakingly trying to initialize them in the right order.
+ */
+void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
+{
+ struct drm_connector *connector, *tmp;
+ struct list_head panel_list;
+
+ INIT_LIST_HEAD(&panel_list);
+
+ list_for_each_entry_safe(connector, tmp,
+ &dev->mode_config.connector_list, head) {
+ if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
+ connector->connector_type == DRM_MODE_CONNECTOR_eDP)
+ list_move_tail(&connector->head, &panel_list);
+ }
+
+ list_splice(&panel_list, &dev->mode_config.connector_list);
+}
+EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
diff --git a/include/drm/drm_kms_helper.h b/include/drm/drm_kms_helper.h
new file mode 100644
index 000000000000..9f3ffb27c871
--- /dev/null
+++ b/include/drm/drm_kms_helper.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef __DRM_KMS_HELPER_H__
+#define __DRM_KMS_HELPER_H__
+
+#include <drm/drmP.h>
+
+extern void drm_helper_move_panel_connectors_to_head(struct drm_device *);
+
+#endif
--
2.8.1
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