On Wed, May 11, 2016 at 06:09:22PM +0200, Noralf Trønnes wrote: > Provides helper functions for drivers that have a simple display > pipeline. Plane, crtc and encoder are collapsed into one entity. > > Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> Looks really nice, just a few suggestions for the kerneldoc. Would be awesome if we could get an ack on this from Jyri for tilcdc, but even without that I think I'll just pull in the next iteration. Still please cc him. Thanks, Daniel > --- > > 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/Kconfig | 7 ++ > drivers/gpu/drm/Makefile | 1 + > drivers/gpu/drm/drm_simple_kms_helper.c | 200 ++++++++++++++++++++++++++++++++ > include/drm/drm_simple_kms_helper.h | 92 +++++++++++++++ > 5 files changed, 306 insertions(+) > 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/Kconfig b/drivers/gpu/drm/Kconfig > index 16e4c21..ff9f480 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -39,6 +39,13 @@ config DRM_KMS_HELPER > help > CRTC helpers for KMS drivers. > > +config DRM_SIMPLE_KMS_HELPER > + tristate > + depends on DRM > + select DRM_KMS_HELPER > + help > + Helpers for very simple KMS drivers. Personally not sold on piles of Kconfig knobs for tiny amounts of code like this one. I'd just drop it. For a more elaborate argument see http://sietch-tagr.blogspot.ch/2016/04/display-panels-are-not-special.html Note that almost all the other helpers do not have a Kconfig option, the only real exception is the fbdev helpers. And those have a good reason: They'd drag in all of fbdev, and that is actually a pile of code. > + > config DRM_KMS_FB_HELPER > bool > depends on DRM_KMS_HELPER > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index 43c2abf..7e99923 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -31,6 +31,7 @@ drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o > drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o > > obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o > +obj-$(CONFIG_DRM_SIMPLE_KMS_HELPER) += drm_simple_kms_helper.o > > CFLAGS_drm_trace_points.o := -I$(src) > > 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..64bf0f2 > --- /dev/null > +++ b/drivers/gpu/drm/drm_simple_kms_helper.c > @@ -0,0 +1,200 @@ > +/* > + * 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 simple drivers. "drivers for simple display hardware" is imo clearer. > + * > + * drm_simple_display_pipe_init() initializes a simple display pipeline > + * consisting of a plane-crtc-encoder pipe coupled with a connector. Hm, I think a bit more text here would be useful. "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; I think the logic above looks correct now, but might be worth checking with your driver that it doesn't let something silly through. I.e. a small test app that tries to reposition the primary plane, or tries to disable it while the crtc is on. We should have that somewhere in libdrm I think. > + > + if (!pipe->funcs || !pipe->funcs->check) > + return 0; > + > + return pipe->funcs->check(pipe, plane_state, crtc_state); > +} > + > +static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane, > + struct drm_plane_state *pstate) > +{ > + struct drm_simple_display_pipe *pipe; > + > + pipe = container_of(plane, struct drm_simple_display_pipe, plane); > + if (!pipe->funcs || !pipe->funcs->update) > + return; > + > + pipe->funcs->update(pipe, pstate); > +} > + > +static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = { > + .atomic_check = drm_simple_kms_plane_atomic_check, > + .atomic_update = drm_simple_kms_plane_atomic_update, > +}; > + > +static const struct drm_plane_funcs drm_simple_kms_plane_funcs = { > + .update_plane = drm_atomic_helper_update_plane, > + .disable_plane = drm_atomic_helper_disable_plane, > + .destroy = drm_plane_cleanup, > + .reset = drm_atomic_helper_plane_reset, > + .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state, > + .atomic_destroy_state = drm_atomic_helper_plane_destroy_state, > +}; > + > +/** > + * drm_simple_display_pipe_init - Initialize a simple display pipeline > + * @dev: DRM device > + * @pipe: simple display pipe object to initialize > + * @funcs: callbacks for the display pipe (optional) > + * @formats: array of supported formats (%DRM_FORMAT_*) > + * @format_count: number of elements in @formats > + * @connector: connector to attach and register > + * > + * Sets up a display pipeline which consist of a really simple > + * plane-crtc-encoder pipe coupled with the provided connector. How are drivers supposed to release this stuff again? Maybe add: "Teardown of a simple display pipe is all handled automatically by the drm core through calling drm_mode_config_cleanup()." > + * > + * Returns: > + * Zero on success, negative error code on failure. > + */ > +int drm_simple_display_pipe_init(struct drm_device *dev, > + struct drm_simple_display_pipe *pipe, > + struct drm_simple_display_pipe_funcs *funcs, > + const uint32_t *formats, > + unsigned int format_count, > + struct drm_connector *connector) > +{ > + struct drm_encoder *encoder = &pipe->encoder; > + struct drm_plane *plane = &pipe->plane; > + struct drm_crtc *crtc = &pipe->crtc; > + int ret; > + > + pipe->funcs = funcs; > + > + drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs); > + ret = drm_universal_plane_init(dev, plane, 0, > + &drm_simple_kms_plane_funcs, > + formats, format_count, > + DRM_PLANE_TYPE_PRIMARY, NULL); > + if (ret) > + return ret; > + > + drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs); > + ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL, > + &drm_simple_kms_crtc_funcs, NULL); > + if (ret) > + return ret; > + > + encoder->possible_crtcs = 1 << drm_crtc_index(crtc); > + ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs, > + DRM_MODE_ENCODER_NONE, NULL); > + if (ret) > + return ret; > + > + ret = drm_mode_connector_attach_encoder(connector, encoder); > + if (ret) > + return ret; > + > + return drm_connector_register(connector); > +} > +EXPORT_SYMBOL(drm_simple_display_pipe_init); > + > +MODULE_LICENSE("GPL"); > diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h > new file mode 100644 > index 0000000..ef578f4 > --- /dev/null > +++ b/include/drm/drm_simple_kms_helper.h > @@ -0,0 +1,92 @@ > +/* > + * 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. > + */ > + > +#ifndef __LINUX_DRM_SIMPLE_KMS_HELPER_H > +#define __LINUX_DRM_SIMPLE_KMS_HELPER_H > + > +struct drm_simple_display_pipe; > + > +/** > + * struct drm_simple_display_pipe_funcs - helper operations for a simple > + * display pipeline > + */ > +struct drm_simple_display_pipe_funcs { > + /** > + * @enable: > + * > + * This function should be used to enable the pipeline. > + * It is called when the underlying crtc is enabled. > + * This hook is optional. > + */ > + void (*enable)(struct drm_simple_display_pipe *pipe, > + struct drm_crtc_state *crtc_state); > + /** > + * @disable: > + * > + * This function should be used to disable the pipeline. > + * It is called when the underlying crtc is disabled. > + * This hook is optional. > + */ > + void (*disable)(struct drm_simple_display_pipe *pipe); > + > + /** > + * @check: > + * > + * This function is called in the check phase of an atomic update, > + * specifically when the underlying plane is checked. I think we need to clarify a bit more what the helpers check already: "The simple display pipeline helpers already check that the plane is not scaled, fills the entire visible area and is always enabled when the crtc is also enabled." > + * This hook is optional. > + * > + * RETURNS: > + * > + * 0 on success, -EINVAL if the state or the transition can't be > + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an > + * attempt to obtain another state object ran into a &drm_modeset_lock > + * deadlock. > + */ > + int (*check)(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *plane_state, > + struct drm_crtc_state *crtc_state); > + /** > + * @update: > + * > + * This function is called when the underlying plane state is updated. > + * This hook is optional. > + */ > + void (*update)(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *plane_state); > +}; > + > +/** > + * struct drm_simple_display_pipe - simple display pipeline > + * @crtc: CRTC control structure > + * @plane: Plane control structure > + * @encoder: Encoder control structure > + * @connector: Connector control structure > + * @funcs: Pipeline control functions (optional) > + * > + * Simple display pipeline with plane, crtc and encoder collapsed into one > + * entity. Maybe add: "It should be initialized by calling drm_simple_display_pipe_init()". Imo never hurts to have a few too many cross references ;-) > + */ > +struct drm_simple_display_pipe { > + struct drm_crtc crtc; > + struct drm_plane plane; > + struct drm_encoder encoder; > + struct drm_connector *connector; > + > + struct drm_simple_display_pipe_funcs *funcs; > +}; > + > +int drm_simple_display_pipe_init(struct drm_device *dev, > + struct drm_simple_display_pipe *pipe, > + struct drm_simple_display_pipe_funcs *funcs, > + const uint32_t *formats, > + unsigned int format_count, > + struct drm_connector *connector); > + > +#endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */ > -- > 2.8.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
