1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
new file mode 100644
index 000000000..40706c5aa
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Rob Clark <rob@ti.com>
+ */
+
+#include <drm/drm_crtc.h>
+#include <drm/drm_util.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_file.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+
+#include "omap_drv.h"
+
+MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
+static bool ywrap_enabled = true;
+module_param_named(ywrap, ywrap_enabled, bool, 0644);
+
+/*
+ * fbdev funcs, to implement legacy fbdev interface on top of drm driver
+ */
+
+#define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
+
+struct omap_fbdev {
+	struct drm_fb_helper base;
+	struct drm_framebuffer *fb;
+	struct drm_gem_object *bo;
+	bool ywrap_enabled;
+
+	/* for deferred dmm roll when getting called in atomic ctx */
+	struct work_struct work;
+};
+
+static struct drm_fb_helper *get_fb(struct fb_info *fbi);
+
+static void pan_worker(struct work_struct *work)
+{
+	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
+	struct fb_info *fbi = fbdev->base.fbdev;
+	int npages;
+
+	/* DMM roll shifts in 4K pages: */
+	npages = fbi->fix.line_length >> PAGE_SHIFT;
+	omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
+}
+
+static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
+		struct fb_info *fbi)
+{
+	struct drm_fb_helper *helper = get_fb(fbi);
+	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
+
+	if (!helper)
+		goto fallback;
+
+	if (!fbdev->ywrap_enabled)
+		goto fallback;
+
+	if (drm_can_sleep()) {
+		pan_worker(&fbdev->work);
+	} else {
+		struct omap_drm_private *priv = helper->dev->dev_private;
+		queue_work(priv->wq, &fbdev->work);
+	}
+
+	return 0;
+
+fallback:
+	return drm_fb_helper_pan_display(var, fbi);
+}
+
+static const struct fb_ops omap_fb_ops = {
+	.owner = THIS_MODULE,
+
+	.fb_check_var	= drm_fb_helper_check_var,
+	.fb_set_par	= drm_fb_helper_set_par,
+	.fb_setcmap	= drm_fb_helper_setcmap,
+	.fb_blank	= drm_fb_helper_blank,
+	.fb_pan_display = omap_fbdev_pan_display,
+	.fb_ioctl	= drm_fb_helper_ioctl,
+
+	.fb_read = drm_fb_helper_sys_read,
+	.fb_write = drm_fb_helper_sys_write,
+	.fb_fillrect = drm_fb_helper_sys_fillrect,
+	.fb_copyarea = drm_fb_helper_sys_copyarea,
+	.fb_imageblit = drm_fb_helper_sys_imageblit,
+};
+
+static int omap_fbdev_create(struct drm_fb_helper *helper,
+		struct drm_fb_helper_surface_size *sizes)
+{
+	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
+	struct drm_device *dev = helper->dev;
+	struct omap_drm_private *priv = dev->dev_private;
+	struct drm_framebuffer *fb = NULL;
+	union omap_gem_size gsize;
+	struct fb_info *fbi = NULL;
+	struct drm_mode_fb_cmd2 mode_cmd = {0};
+	dma_addr_t dma_addr;
+	int ret;
+
+	sizes->surface_bpp = 32;
+	sizes->surface_depth = 24;
+
+	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
+			sizes->surface_height, sizes->surface_bpp,
+			sizes->fb_width, sizes->fb_height);
+
+	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+			sizes->surface_depth);
+
+	mode_cmd.width = sizes->surface_width;
+	mode_cmd.height = sizes->surface_height;
+
+	mode_cmd.pitches[0] =
+			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
+
+	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
+	if (fbdev->ywrap_enabled) {
+		/* need to align pitch to page size if using DMM scrolling */
+		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
+	}
+
+	/* allocate backing bo */
+	gsize = (union omap_gem_size){
+		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
+	};
+	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
+	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
+	if (!fbdev->bo) {
+		dev_err(dev->dev, "failed to allocate buffer object\n");
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
+	if (IS_ERR(fb)) {
+		dev_err(dev->dev, "failed to allocate fb\n");
+		/* note: if fb creation failed, we can't rely on fb destroy
+		 * to unref the bo:
+		 */
+		drm_gem_object_put(fbdev->bo);
+		ret = PTR_ERR(fb);
+		goto fail;
+	}
+
+	/* note: this keeps the bo pinned.. which is perhaps not ideal,
+	 * but is needed as long as we use fb_mmap() to mmap to userspace
+	 * (since this happens using fix.smem_start).  Possibly we could
+	 * implement our own mmap using GEM mmap support to avoid this
+	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
+	 * to it).  Then we just need to be sure that we are able to re-
+	 * pin it in case of an opps.
+	 */
+	ret = omap_gem_pin(fbdev->bo, &dma_addr);
+	if (ret) {
+		dev_err(dev->dev, "could not pin framebuffer\n");
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	fbi = drm_fb_helper_alloc_fbi(helper);
+	if (IS_ERR(fbi)) {
+		dev_err(dev->dev, "failed to allocate fb info\n");
+		ret = PTR_ERR(fbi);
+		goto fail;
+	}
+
+	DBG("fbi=%p, dev=%p", fbi, dev);
+
+	fbdev->fb = fb;
+	helper->fb = fb;
+
+	fbi->fbops = &omap_fb_ops;
+
+	drm_fb_helper_fill_info(fbi, helper, sizes);
+
+	dev->mode_config.fb_base = dma_addr;
+
+	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
+	fbi->screen_size = fbdev->bo->size;
+	fbi->fix.smem_start = dma_addr;
+	fbi->fix.smem_len = fbdev->bo->size;
+
+	/* if we have DMM, then we can use it for scrolling by just
+	 * shuffling pages around in DMM rather than doing sw blit.
+	 */
+	if (fbdev->ywrap_enabled) {
+		DRM_INFO("Enabling DMM ywrap scrolling\n");
+		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
+		fbi->fix.ywrapstep = 1;
+	}
+
+
+	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
+	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
+
+	return 0;
+
+fail:
+
+	if (ret) {
+		if (fb)
+			drm_framebuffer_remove(fb);
+	}
+
+	return ret;
+}
+
+static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
+	.fb_probe = omap_fbdev_create,
+};
+
+static struct drm_fb_helper *get_fb(struct fb_info *fbi)
+{
+	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
+		/* these are not the fb's you're looking for */
+		return NULL;
+	}
+	return fbi->par;
+}
+
+/* initialize fbdev helper */
+void omap_fbdev_init(struct drm_device *dev)
+{
+	struct omap_drm_private *priv = dev->dev_private;
+	struct omap_fbdev *fbdev = NULL;
+	struct drm_fb_helper *helper;
+	int ret = 0;
+
+	if (!priv->num_pipes)
+		return;
+
+	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
+	if (!fbdev)
+		goto fail;
+
+	INIT_WORK(&fbdev->work, pan_worker);
+
+	helper = &fbdev->base;
+
+	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
+
+	ret = drm_fb_helper_init(dev, helper);
+	if (ret)
+		goto fail;
+
+	ret = drm_fb_helper_initial_config(helper, 32);
+	if (ret)
+		goto fini;
+
+	priv->fbdev = helper;
+
+	return;
+
+fini:
+	drm_fb_helper_fini(helper);
+fail:
+	kfree(fbdev);
+
+	dev_warn(dev->dev, "omap_fbdev_init failed\n");
+}
+
+void omap_fbdev_fini(struct drm_device *dev)
+{
+	struct omap_drm_private *priv = dev->dev_private;
+	struct drm_fb_helper *helper = priv->fbdev;
+	struct omap_fbdev *fbdev;
+
+	DBG();
+
+	if (!helper)
+		return;
+
+	drm_fb_helper_unregister_fbi(helper);
+
+	drm_fb_helper_fini(helper);
+
+	fbdev = to_omap_fbdev(helper);
+
+	/* unpin the GEM object pinned in omap_fbdev_create() */
+	if (fbdev->bo)
+		omap_gem_unpin(fbdev->bo);
+
+	/* this will free the backing object */
+	if (fbdev->fb)
+		drm_framebuffer_remove(fbdev->fb);
+
+	kfree(fbdev);
+
+	priv->fbdev = NULL;
+}