linux/drivers/gpu/drm/drm_simple_kms_helper.c
Thomas Zimmermann 2cb5974dca drm/simple-kms: Fix documentation for drm_simple_encoder_init()
Brings the documentation of drm_simple_encoder_init() in sync with the
function's signature. Also add a paragraph clarifying the management of
the encoder's memory.

v2:
	* document memory management

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes: 63170ac6f2 ("drm/simple-kms: Add drm_simple_encoder_{init,create}()")
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200304145312.26458-1-tzimmermann@suse.de
2020-03-06 09:24:29 +01:00

339 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Noralf Trønnes
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.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.
*
* Many drivers require only a very simple encoder that fulfills the minimum
* requirements of the display pipeline and does not add additional
* functionality. The function drm_simple_encoder_init() provides an
* implementation of such an encoder.
*/
static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = {
.destroy = drm_encoder_cleanup,
};
/**
* drm_simple_encoder_init - Initialize a preallocated encoder with
* basic functionality.
* @dev: drm device
* @encoder: the encoder to initialize
* @encoder_type: user visible type of the encoder
*
* Initialises a preallocated encoder that has no further functionality.
* Settings for possible CRTC and clones are left to their initial values.
* The encoder will be cleaned up automatically as part of the mode-setting
* cleanup.
*
* The caller of drm_simple_encoder_init() is responsible for freeing
* the encoder's memory after the encoder has been cleaned up. At the
* moment this only works reliably if the encoder data structure is
* stored in the device structure. Free the encoder's memory as part of
* the device release function.
*
* FIXME: Later improvements to DRM's resource management may allow for
* an automated kfree() of the encoder's memory.
*
* Returns:
* Zero on success, error code on failure.
*/
int drm_simple_encoder_init(struct drm_device *dev,
struct drm_encoder *encoder,
int encoder_type)
{
return drm_encoder_init(dev, encoder,
&drm_simple_encoder_funcs_cleanup,
encoder_type, NULL);
}
EXPORT_SYMBOL(drm_simple_encoder_init);
static enum drm_mode_status
drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
{
struct drm_simple_display_pipe *pipe;
pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
if (!pipe->funcs || !pipe->funcs->mode_valid)
/* Anything goes */
return MODE_OK;
return pipe->funcs->mode_valid(pipe, mode);
}
static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
struct drm_crtc_state *state)
{
bool has_primary = state->plane_mask &
drm_plane_mask(crtc->primary);
/* We always want to have an active plane with an active CRTC */
if (has_primary != state->enable)
return -EINVAL;
return drm_atomic_add_affected_planes(state->state, crtc);
}
static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
struct drm_plane *plane;
struct drm_simple_display_pipe *pipe;
pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
if (!pipe->funcs || !pipe->funcs->enable)
return;
plane = &pipe->plane;
pipe->funcs->enable(pipe, crtc->state, plane->state);
}
static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
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 = {
.mode_valid = drm_simple_kms_crtc_mode_valid,
.atomic_check = drm_simple_kms_crtc_check,
.atomic_enable = drm_simple_kms_crtc_enable,
.atomic_disable = drm_simple_kms_crtc_disable,
};
static int drm_simple_kms_crtc_enable_vblank(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_vblank)
return 0;
return pipe->funcs->enable_vblank(pipe);
}
static void drm_simple_kms_crtc_disable_vblank(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_vblank)
return;
pipe->funcs->disable_vblank(pipe);
}
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,
.enable_vblank = drm_simple_kms_crtc_enable_vblank,
.disable_vblank = drm_simple_kms_crtc_disable_vblank,
};
static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
struct drm_plane_state *plane_state)
{
struct drm_simple_display_pipe *pipe;
struct drm_crtc_state *crtc_state;
int ret;
pipe = container_of(plane, struct drm_simple_display_pipe, plane);
crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
&pipe->crtc);
ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
DRM_PLANE_HELPER_NO_SCALING,
DRM_PLANE_HELPER_NO_SCALING,
false, true);
if (ret)
return ret;
if (!plane_state->visible)
return 0;
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 *old_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, old_pstate);
}
static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
struct drm_plane_state *state)
{
struct drm_simple_display_pipe *pipe;
pipe = container_of(plane, struct drm_simple_display_pipe, plane);
if (!pipe->funcs || !pipe->funcs->prepare_fb)
return 0;
return pipe->funcs->prepare_fb(pipe, state);
}
static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
struct drm_plane_state *state)
{
struct drm_simple_display_pipe *pipe;
pipe = container_of(plane, struct drm_simple_display_pipe, plane);
if (!pipe->funcs || !pipe->funcs->cleanup_fb)
return;
pipe->funcs->cleanup_fb(pipe, state);
}
static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
uint32_t format,
uint64_t modifier)
{
return modifier == DRM_FORMAT_MOD_LINEAR;
}
static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
.prepare_fb = drm_simple_kms_plane_prepare_fb,
.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
.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,
.format_mod_supported = drm_simple_kms_format_mod_supported,
};
/**
* drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
* @pipe: simple display pipe object
* @bridge: bridge to attach
*
* Makes it possible to still use the drm_simple_display_pipe helpers when
* a DRM bridge has to be used.
*
* Note that you probably want to initialize the pipe by passing a NULL
* connector to drm_simple_display_pipe_init().
*
* Returns:
* Zero on success, negative error code on failure.
*/
int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
struct drm_bridge *bridge)
{
return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
}
EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
/**
* 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
* @format_modifiers: array of formats modifiers
* @connector: connector to attach and register (optional)
*
* Sets up a display pipeline which consist of a really simple
* plane-crtc-encoder pipe.
*
* If a connector is supplied, the pipe will be coupled with the provided
* connector. You may supply a NULL connector when using drm bridges, that
* handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
*
* Teardown of a simple display pipe is all handled automatically by the drm
* core through calling drm_mode_config_cleanup(). Drivers afterwards need to
* release the memory for the structure themselves.
*
* 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,
const struct drm_simple_display_pipe_funcs *funcs,
const uint32_t *formats, unsigned int format_count,
const uint64_t *format_modifiers,
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->connector = connector;
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,
format_modifiers,
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 = drm_crtc_mask(crtc);
ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
if (ret || !connector)
return ret;
return drm_connector_attach_encoder(connector, encoder);
}
EXPORT_SYMBOL(drm_simple_display_pipe_init);
MODULE_LICENSE("GPL");