Re: [PATCH v4 3/3] drm: Add helper for simple display pipeline

On Tue, May 17, 2016 at 09:05:01AM +0200, Daniel Vetter wrote:

On Thu, May 12, 2016 at 09:36:14PM +0300, Ville Syrjälä wrote:

...

On Thu, May 12, 2016 at 08:25:23PM +0200, Noralf Trønnes wrote:

...

Provides helper functions for drivers that have a simple display pipeline. Plane, crtc and encoder are collapsed into one entity.

Cc: jsarha@ti.com Signed-off-by: Noralf Trønnes noralf@tronnes.org

---

Changes since v3:

• (struct drm_simple_display_pipe *)->funcs should be const

Changes since v2:

• Drop Kconfig knob DRM_KMS_HELPER
• Expand documentation

Changes since v1:

• Add DOC header and add to gpu.tmpl
• Fix docs: @funcs is optional, "negative error code", "This hook is optional."
• Add checks to drm_simple_kms_plane_atomic_check()

Documentation/DocBook/gpu.tmpl | 6 + drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_simple_kms_helper.c | 208 ++++++++++++++++++++++++++++++++ include/drm/drm_simple_kms_helper.h | 94 +++++++++++++++ 4 files changed, 309 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/drm_simple_kms_helper.c create mode 100644 include/drm/drm_simple_kms_helper.h

diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl index 4a0c599..cf3f5a8 100644 --- a/Documentation/DocBook/gpu.tmpl +++ b/Documentation/DocBook/gpu.tmpl @@ -1693,6 +1693,12 @@ void intel_crt_init(struct drm_device *dev) !Edrivers/gpu/drm/drm_panel.c !Pdrivers/gpu/drm/drm_panel.c drm panel </sect2>

• <sect2>

•  <title>Simple KMS Helper Reference</title>
  

+!Iinclude/drm/drm_simple_kms_helper.h +!Edrivers/gpu/drm/drm_simple_kms_helper.c +!Pdrivers/gpu/drm/drm_simple_kms_helper.c overview

• </sect2> </sect1>

  <!-- Internals: kms properties -->

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 2bd3e5a..31b85df5 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -23,7 +23,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o

drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \

• drm_kms_helper_common.o
  

• drm_kms_helper_common.o drm_simple_kms_helper.o
  
  

drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c new file mode 100644 index 0000000..d45417a --- /dev/null +++ b/drivers/gpu/drm/drm_simple_kms_helper.c @@ -0,0 +1,208 @@ +/*

• • Copyright (C) 2016 Noralf Trønnes
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• */

+#include <drm/drmP.h> +#include <drm/drm_atomic.h> +#include <drm/drm_atomic_helper.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_plane_helper.h> +#include <drm/drm_simple_kms_helper.h> +#include <linux/slab.h>

+/**

• • DOC: overview
• • This helper library provides helpers for drivers for simple display
• • hardware.
• • drm_simple_display_pipe_init() initializes a simple display pipeline
• • which has only one full-screen scanout buffer feeding one output. The
• • pipeline is represented by struct &drm_simple_display_pipe and binds
• • together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
• • entity. Some flexibility for code reuse is provided through a separately
• • allocated &drm_connector object and supporting optional &drm_bridge
• • encoder drivers.
• */

+static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {

• .destroy = drm_encoder_cleanup,

+};

+static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc) +{

• struct drm_simple_display_pipe *pipe;
• pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
• if (!pipe->funcs || !pipe->funcs->enable)

• return;
  

• pipe->funcs->enable(pipe, crtc->state);

+}

+static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc) +{

• struct drm_simple_display_pipe *pipe;
• pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
• if (!pipe->funcs || !pipe->funcs->disable)

• return;
  

• pipe->funcs->disable(pipe);

+}

+static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {

• .disable = drm_simple_kms_crtc_disable,
• .enable = drm_simple_kms_crtc_enable,

+};

+static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {

• .reset = drm_atomic_helper_crtc_reset,
• .destroy = drm_crtc_cleanup,
• .set_config = drm_atomic_helper_set_config,
• .page_flip = drm_atomic_helper_page_flip,
• .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
• .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,

+};

+static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,

• 			struct drm_plane_state *plane_state)
  

+{

• struct drm_rect src = {

• .x1 = plane_state->src_x,
  

• .y1 = plane_state->src_y,
  

• .x2 = plane_state->src_x + plane_state->src_w,
  

• .y2 = plane_state->src_y + plane_state->src_h,
  

• };
• struct drm_rect dest = {

• .x1 = plane_state->crtc_x,
  

• .y1 = plane_state->crtc_y,
  

• .x2 = plane_state->crtc_x + plane_state->crtc_w,
  

• .y2 = plane_state->crtc_y + plane_state->crtc_h,
  

• };
• struct drm_rect clip = { 0 };
• struct drm_simple_display_pipe *pipe;
• struct drm_crtc_state *crtc_state;
• bool visible;
• int ret;
• pipe = container_of(plane, struct drm_simple_display_pipe, plane);
• crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,

• 					&pipe->crtc);
  

• if (crtc_state->enable != !!plane_state->crtc)

• return -EINVAL; /* plane must match crtc enable state */
  

• if (!crtc_state->enable)

• return 0; /* nothing to check when disabling or disabled */
  

• clip.x2 = crtc_state->adjusted_mode.hdisplay;
• clip.y2 = crtc_state->adjusted_mode.vdisplay;
• ret = drm_plane_helper_check_update(plane, &pipe->crtc,

• 			    plane_state->fb,
  

• 			    &src, &dest, &clip,
  

• 			    DRM_PLANE_HELPER_NO_SCALING,
  

• 			    DRM_PLANE_HELPER_NO_SCALING,
  

• 			    false, true, &visible);
  

• if (ret)

• return ret;
  

• if (!visible)

• return -EINVAL;
  

• if (!pipe->funcs || !pipe->funcs->check)

• return 0;
  

• return pipe->funcs->check(pipe, plane_state, crtc_state);

+}

What's anyone supposed to do with this when the clipped coordinates aren't even passed/stored anywhere?

It disallows positioning and scaling, so shouldn't ever need to have the clipped area?

You can still configure a larger area that gets clipped to the fullscreen dimensions.