drivers/gpu/drm/gma500/fbdev.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/gma500/fbdev.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/gma500/fbdev.c
Extension
.c
Size
5266 bytes
Lines
196
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source 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

if (ret == -EBUSY && sizes->surface_bpp > 16) {
			/*
			 * If the mode does not fit in 32 bit then switch to 16 bit to
			 * get a console on full resolution. User-space compositors will
			 * allocate their own 32-bit framebuffers.
			 */
			sizes->surface_bpp = 16;
			sizes->surface_depth = 16;
			goto try_psb_gem_create;
		}
		return ret;
	}
	obj = &backing->base;

	ret = drm_gem_handle_create(file, obj, &handle);
	if (ret)
		goto err_drm_gem_object_put;

	buffer = drm_client_buffer_create(client, sizes->surface_width, sizes->surface_height,
					  fourcc, handle, pitch);
	if (IS_ERR(buffer)) {
		ret = PTR_ERR(buffer);
		goto err_drm_gem_handle_delete;
	}

	fb_helper->funcs = &psb_fbdev_fb_helper_funcs;
	fb_helper->buffer = buffer;
	fb_helper->fb = buffer->fb;

	info->fbops = &psb_fbdev_fb_ops;

	/* Accessed stolen memory directly */
	info->screen_base = dev_priv->vram_addr + backing->offset;
	info->screen_size = obj->size;

	drm_fb_helper_fill_info(info, fb_helper, sizes);

	info->fix.smem_start = dev_priv->stolen_base + backing->offset;
	info->fix.smem_len = obj->size;
	info->fix.ywrapstep = 0;
	info->fix.ypanstep = 0;
	info->fix.mmio_start = pci_resource_start(pdev, 0);
	info->fix.mmio_len = pci_resource_len(pdev, 0);

	fb_memset_io(info->screen_base, 0, info->screen_size);

	/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */

	dev_dbg(dev->dev, "allocated %dx%d fb\n", buffer->fb->width, buffer->fb->height);

	/* The handle is only needed for creating the framebuffer.*/
	drm_gem_handle_delete(file, handle);

	/* The framebuffer still holds a references on the GEM object. */
	drm_gem_object_put(obj);

	return 0;

err_drm_gem_handle_delete:
	drm_gem_handle_delete(file, handle);
err_drm_gem_object_put:
	drm_gem_object_put(obj);
	return ret;
}

Annotation

Implementation Notes