drivers/gpu/drm/drm_plane_helper.c - linux - Git at Google

 /*
  * Copyright (C) 2014 Intel Corporation
  *
  * DRM universal plane helper functions
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */

 #include <linux/list.h>

 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_atomic_uapi.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_print.h>
 #include <drm/drm_rect.h>

 #define SUBPIXEL_MASK 0xffff

 /**
  * DOC: overview
  *
  * This helper library contains helpers to implement primary plane support on
  * top of the normal CRTC configuration interface.
  * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
  * plane together with the CRTC state this does not allow userspace to disable
  * the primary plane itself. The default primary plane only expose XRBG8888 and
  * ARGB8888 as valid pixel formats for the attached framebuffer.
  *
  * Drivers are highly recommended to implement proper support for primary
  * planes, and newly merged drivers must not rely upon these transitional
  * helpers.
  *
  * The plane helpers share the function table structures with other helpers,
  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
  * the details.
  */

 /*
  * Returns the connectors currently associated with a CRTC.  This function
  * should be called twice:  once with a NULL connector list to retrieve
  * the list size, and once with the properly allocated list to be filled in.
  */
 static int get_connectors_for_crtc(struct drm_crtc *crtc,
 				   struct drm_connector **connector_list,
 				   int num_connectors)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
 	int count = 0;

 	/*
 	 * Note: Once we change the plane hooks to more fine-grained locking we
 	 * need to grab the connection_mutex here to be able to make these
 	 * checks.
 	 */
 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));

 	drm_connector_list_iter_begin(dev, &conn_iter);
 	drm_for_each_connector_iter(connector, &conn_iter) {
 		if (connector->encoder && connector->encoder->crtc == crtc) {
 			if (connector_list != NULL && count < num_connectors)
 				*(connector_list++) = connector;

 			count++;
 		}
 	}
 	drm_connector_list_iter_end(&conn_iter);

 	return count;
 }

 static int drm_plane_helper_check_update(struct drm_plane *plane,
 					 struct drm_crtc *crtc,
 					 struct drm_framebuffer *fb,
 					 struct drm_rect *src,
 					 struct drm_rect *dst,
 					 unsigned int rotation,
 					 int min_scale,
 					 int max_scale,
 					 bool can_position,
 					 bool can_update_disabled,
 					 bool *visible)
 {
 	struct drm_plane_state plane_state = {
 		.plane = plane,
 		.crtc = crtc,
 		.fb = fb,
 		.src_x = src->x1,
 		.src_y = src->y1,
 		.src_w = drm_rect_width(src),
 		.src_h = drm_rect_height(src),
 		.crtc_x = dst->x1,
 		.crtc_y = dst->y1,
 		.crtc_w = drm_rect_width(dst),
 		.crtc_h = drm_rect_height(dst),
 		.rotation = rotation,
 	};
 	struct drm_crtc_state crtc_state = {
 		.crtc = crtc,
 		.enable = crtc->enabled,
 		.mode = crtc->mode,
 	};
 	int ret;

 	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
 						  min_scale, max_scale,
 						  can_position,
 						  can_update_disabled);
 	if (ret)
 		return ret;

 	*src = plane_state.src;
 	*dst = plane_state.dst;
 	*visible = plane_state.visible;

 	return 0;
 }

 /**
  * drm_plane_helper_update_primary - Helper for updating primary planes
  * @plane: plane to update
  * @crtc: the plane's new CRTC
  * @fb: the plane's new framebuffer
  * @crtc_x: x coordinate within CRTC
  * @crtc_y: y coordinate within CRTC
  * @crtc_w: width coordinate within CRTC
  * @crtc_h: height coordinate within CRTC
  * @src_x: x coordinate within source
  * @src_y: y coordinate within source
  * @src_w: width coordinate within source
  * @src_h: height coordinate within source
  * @ctx: modeset locking context
  *
  * This helper validates the given parameters and updates the primary plane.
  *
  * This function is only useful for non-atomic modesetting. Don't use
  * it in new drivers.
  *
  * Returns:
  * Zero on success, or an errno code otherwise.
  */
 int drm_plane_helper_update_primary(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,
 				    struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_mode_set set = {
 		.crtc = crtc,
 		.fb = fb,
 		.mode = &crtc->mode,
 		.x = src_x >> 16,
 		.y = src_y >> 16,
 	};
 	struct drm_rect src = {
 		.x1 = src_x,
 		.y1 = src_y,
 		.x2 = src_x + src_w,
 		.y2 = src_y + src_h,
 	};
 	struct drm_rect dest = {
 		.x1 = crtc_x,
 		.y1 = crtc_y,
 		.x2 = crtc_x + crtc_w,
 		.y2 = crtc_y + crtc_h,
 	};
 	struct drm_device *dev = plane->dev;
 	struct drm_connector **connector_list;
 	int num_connectors, ret;
 	bool visible;

 	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
 		return -EINVAL;

 	ret = drm_plane_helper_check_update(plane, crtc, fb,
 					    &src, &dest,
 					    DRM_MODE_ROTATE_0,
 					    DRM_PLANE_NO_SCALING,
 					    DRM_PLANE_NO_SCALING,
 					    false, false, &visible);
 	if (ret)
 		return ret;

 	if (!visible)
 		/*
 		 * Primary plane isn't visible.  Note that unless a driver
 		 * provides their own disable function, this will just
 		 * wind up returning -EINVAL to userspace.
 		 */
 		return plane->funcs->disable_plane(plane, ctx);

 	/* Find current connectors for CRTC */
 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 	BUG_ON(num_connectors == 0);
 	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
 				 GFP_KERNEL);
 	if (!connector_list)
 		return -ENOMEM;
 	get_connectors_for_crtc(crtc, connector_list, num_connectors);

 	set.connectors = connector_list;
 	set.num_connectors = num_connectors;

 	/*
 	 * We call set_config() directly here rather than using
 	 * drm_mode_set_config_internal.  We're reprogramming the same
 	 * connectors that were already in use, so we shouldn't need the extra
 	 * cross-CRTC fb refcounting to accommodate stealing connectors.
 	 * drm_mode_setplane() already handles the basic refcounting for the
 	 * framebuffers involved in this operation.
 	 */
 	ret = crtc->funcs->set_config(&set, ctx);

 	kfree(connector_list);
 	return ret;
 }
 EXPORT_SYMBOL(drm_plane_helper_update_primary);

 /**
  * drm_plane_helper_disable_primary - Helper for disabling primary planes
  * @plane: plane to disable
  * @ctx: modeset locking context
  *
  * This helper returns an error when trying to disable the primary
  * plane.
  *
  * This function is only useful for non-atomic modesetting. Don't use
  * it in new drivers.
  *
  * Returns:
  * An errno code.
  */
 int drm_plane_helper_disable_primary(struct drm_plane *plane,
 				     struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_device *dev = plane->dev;

 	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));

 	return -EINVAL;
 }
 EXPORT_SYMBOL(drm_plane_helper_disable_primary);

 /**
  * drm_plane_helper_destroy() - Helper for primary plane destruction
  * @plane: plane to destroy
  *
  * Provides a default plane destroy handler for primary planes.  This handler
  * is called during CRTC destruction.  We disable the primary plane, remove
  * it from the DRM plane list, and deallocate the plane structure.
  */
 void drm_plane_helper_destroy(struct drm_plane *plane)
 {
 	drm_plane_cleanup(plane);
 	kfree(plane);
 }
 EXPORT_SYMBOL(drm_plane_helper_destroy);
	/*
	* Copyright (C) 2014 Intel Corporation
	*
	* DRM universal plane helper functions
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*/

	#include <linux/list.h>

	#include <drm/drm_atomic.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_atomic_uapi.h>
	#include <drm/drm_device.h>
	#include <drm/drm_drv.h>
	#include <drm/drm_encoder.h>
	#include <drm/drm_plane_helper.h>
	#include <drm/drm_print.h>
	#include <drm/drm_rect.h>

	#define SUBPIXEL_MASK 0xffff

	/**
	* DOC: overview
	*
	* This helper library contains helpers to implement primary plane support on
	* top of the normal CRTC configuration interface.
	* Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
	* plane together with the CRTC state this does not allow userspace to disable
	* the primary plane itself. The default primary plane only expose XRBG8888 and
	* ARGB8888 as valid pixel formats for the attached framebuffer.
	*
	* Drivers are highly recommended to implement proper support for primary
	* planes, and newly merged drivers must not rely upon these transitional
	* helpers.
	*
	* The plane helpers share the function table structures with other helpers,
	* specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
	* the details.
	*/

	/*
	* Returns the connectors currently associated with a CRTC. This function
	* should be called twice: once with a NULL connector list to retrieve
	* the list size, and once with the properly allocated list to be filled in.
	*/
	static int get_connectors_for_crtc(struct drm_crtc *crtc,
	struct drm_connector **connector_list,
	int num_connectors)
	{
	struct drm_device *dev = crtc->dev;
	struct drm_connector *connector;
	struct drm_connector_list_iter conn_iter;
	int count = 0;

	/*
	* Note: Once we change the plane hooks to more fine-grained locking we
	* need to grab the connection_mutex here to be able to make these
	* checks.
	*/
	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));

	drm_connector_list_iter_begin(dev, &conn_iter);
	drm_for_each_connector_iter(connector, &conn_iter) {
	if (connector->encoder && connector->encoder->crtc == crtc) {
	if (connector_list != NULL && count < num_connectors)
	*(connector_list++) = connector;

	count++;
	}
	}
	drm_connector_list_iter_end(&conn_iter);

	return count;
	}

	static int drm_plane_helper_check_update(struct drm_plane *plane,
	struct drm_crtc *crtc,
	struct drm_framebuffer *fb,
	struct drm_rect *src,
	struct drm_rect *dst,
	unsigned int rotation,
	int min_scale,
	int max_scale,
	bool can_position,
	bool can_update_disabled,
	bool *visible)
	{
	struct drm_plane_state plane_state = {
	.plane = plane,
	.crtc = crtc,
	.fb = fb,
	.src_x = src->x1,
	.src_y = src->y1,
	.src_w = drm_rect_width(src),
	.src_h = drm_rect_height(src),
	.crtc_x = dst->x1,
	.crtc_y = dst->y1,
	.crtc_w = drm_rect_width(dst),
	.crtc_h = drm_rect_height(dst),
	.rotation = rotation,
	};
	struct drm_crtc_state crtc_state = {
	.crtc = crtc,
	.enable = crtc->enabled,
	.mode = crtc->mode,
	};
	int ret;

	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
	min_scale, max_scale,
	can_position,
	can_update_disabled);
	if (ret)
	return ret;

	*src = plane_state.src;
	*dst = plane_state.dst;
	*visible = plane_state.visible;

	return 0;
	}

	/**
	* drm_plane_helper_update_primary - Helper for updating primary planes
	* @plane: plane to update
	* @crtc: the plane's new CRTC
	* @fb: the plane's new framebuffer
	* @crtc_x: x coordinate within CRTC
	* @crtc_y: y coordinate within CRTC
	* @crtc_w: width coordinate within CRTC
	* @crtc_h: height coordinate within CRTC
	* @src_x: x coordinate within source
	* @src_y: y coordinate within source
	* @src_w: width coordinate within source
	* @src_h: height coordinate within source
	* @ctx: modeset locking context
	*
	* This helper validates the given parameters and updates the primary plane.
	*
	* This function is only useful for non-atomic modesetting. Don't use
	* it in new drivers.
	*
	* Returns:
	* Zero on success, or an errno code otherwise.
	*/
	int drm_plane_helper_update_primary(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,
	struct drm_modeset_acquire_ctx *ctx)
	{
	struct drm_mode_set set = {
	.crtc = crtc,
	.fb = fb,
	.mode = &crtc->mode,
	.x = src_x >> 16,
	.y = src_y >> 16,
	};
	struct drm_rect src = {
	.x1 = src_x,
	.y1 = src_y,
	.x2 = src_x + src_w,
	.y2 = src_y + src_h,
	};
	struct drm_rect dest = {
	.x1 = crtc_x,
	.y1 = crtc_y,
	.x2 = crtc_x + crtc_w,
	.y2 = crtc_y + crtc_h,
	};
	struct drm_device *dev = plane->dev;
	struct drm_connector **connector_list;
	int num_connectors, ret;
	bool visible;

	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
	return -EINVAL;

	ret = drm_plane_helper_check_update(plane, crtc, fb,
	&src, &dest,
	DRM_MODE_ROTATE_0,
	DRM_PLANE_NO_SCALING,
	DRM_PLANE_NO_SCALING,
	false, false, &visible);
	if (ret)
	return ret;

	if (!visible)
	/*
	* Primary plane isn't visible. Note that unless a driver
	* provides their own disable function, this will just
	* wind up returning -EINVAL to userspace.
	*/
	return plane->funcs->disable_plane(plane, ctx);

	/* Find current connectors for CRTC */
	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
	BUG_ON(num_connectors == 0);
	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
	GFP_KERNEL);
	if (!connector_list)
	return -ENOMEM;
	get_connectors_for_crtc(crtc, connector_list, num_connectors);

	set.connectors = connector_list;
	set.num_connectors = num_connectors;

	/*
	* We call set_config() directly here rather than using
	* drm_mode_set_config_internal. We're reprogramming the same
	* connectors that were already in use, so we shouldn't need the extra
	* cross-CRTC fb refcounting to accommodate stealing connectors.
	* drm_mode_setplane() already handles the basic refcounting for the
	* framebuffers involved in this operation.
	*/
	ret = crtc->funcs->set_config(&set, ctx);

	kfree(connector_list);
	return ret;
	}
	EXPORT_SYMBOL(drm_plane_helper_update_primary);

	/**
	* drm_plane_helper_disable_primary - Helper for disabling primary planes
	* @plane: plane to disable
	* @ctx: modeset locking context
	*
	* This helper returns an error when trying to disable the primary
	* plane.
	*
	* This function is only useful for non-atomic modesetting. Don't use
	* it in new drivers.
	*
	* Returns:
	* An errno code.
	*/
	int drm_plane_helper_disable_primary(struct drm_plane *plane,
	struct drm_modeset_acquire_ctx *ctx)
	{
	struct drm_device *dev = plane->dev;

	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));

	return -EINVAL;
	}
	EXPORT_SYMBOL(drm_plane_helper_disable_primary);

	/**
	* drm_plane_helper_destroy() - Helper for primary plane destruction
	* @plane: plane to destroy
	*
	* Provides a default plane destroy handler for primary planes. This handler
	* is called during CRTC destruction. We disable the primary plane, remove
	* it from the DRM plane list, and deallocate the plane structure.
	*/
	void drm_plane_helper_destroy(struct drm_plane *plane)
	{
	drm_plane_cleanup(plane);
	kfree(plane);
	}
	EXPORT_SYMBOL(drm_plane_helper_destroy);