drivers/gpu/drm/drm_modeset_helper.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/drm_modeset_helper.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/drm_modeset_helper.c
Extension
.c
Size
7951 bytes
Lines
263
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/export.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_client_event.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_modeset_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.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/DSI) 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);

	spin_lock_irq(&dev->mode_config.connector_list_lock);
	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 ||
		    connector->connector_type == DRM_MODE_CONNECTOR_DSI)
			list_move_tail(&connector->head, &panel_list);
	}

	list_splice(&panel_list, &dev->mode_config.connector_list);
	spin_unlock_irq(&dev->mode_config.connector_list_lock);
}
EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);

/**
 * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
 * @dev: DRM device
 * @fb: drm_framebuffer object to fill out
 * @info: pixel format information
 * @mode_cmd: metadata from the userspace fb creation request
 *
 * This helper can be used in a drivers fb_create callback to pre-fill the fb's
 * metadata fields.
 */
void drm_helper_mode_fill_fb_struct(struct drm_device *dev,
				    struct drm_framebuffer *fb,
				    const struct drm_format_info *info,
				    const struct drm_mode_fb_cmd2 *mode_cmd)
{
	int i;

	fb->dev = dev;
	fb->format = info;
	fb->width = mode_cmd->width;
	fb->height = mode_cmd->height;
	for (i = 0; i < 4; i++) {
		fb->pitches[i] = mode_cmd->pitches[i];
		fb->offsets[i] = mode_cmd->offsets[i];
	}
	fb->modifier = mode_cmd->modifier[0];
	fb->flags = mode_cmd->flags;
}
EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);

/*
 * This is the minimal list of formats that seem to be safe for modeset use
 * with all current DRM drivers.  Most hardware can actually support more
 * formats than this and drivers may specify a more accurate list when
 * creating the primary plane.
 */
static const uint32_t safe_modeset_formats[] = {
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_ARGB8888,
};

Annotation

Implementation Notes