--- /dev/null
- format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
+ // SPDX-License-Identifier: MIT
+
+ #include <linux/moduleparam.h>
+ #include <linux/vmalloc.h>
+
+ #include <drm/drm_crtc_helper.h>
+ #include <drm/drm_drv.h>
+ #include <drm/drm_fb_helper.h>
+ #include <drm/drm_framebuffer.h>
+ #include <drm/drm_gem.h>
+ #include <drm/drm_print.h>
+
+ #include <drm/drm_fbdev_ttm.h>
+
+ /* @user: 1=userspace, 0=fbcon */
+ static int drm_fbdev_ttm_fb_open(struct fb_info *info, int user)
+ {
+ struct drm_fb_helper *fb_helper = info->par;
+
+ /* No need to take a ref for fbcon because it unbinds on unregister */
+ if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
+ return -ENODEV;
+
+ return 0;
+ }
+
+ static int drm_fbdev_ttm_fb_release(struct fb_info *info, int user)
+ {
+ struct drm_fb_helper *fb_helper = info->par;
+
+ if (user)
+ module_put(fb_helper->dev->driver->fops->owner);
+
+ return 0;
+ }
+
+ FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_ttm,
+ drm_fb_helper_damage_range,
+ drm_fb_helper_damage_area);
+
+ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
+ {
+ struct drm_fb_helper *fb_helper = info->par;
+ void *shadow = info->screen_buffer;
+
+ if (!fb_helper->dev)
+ return;
+
+ fb_deferred_io_cleanup(info);
+ drm_fb_helper_fini(fb_helper);
+ vfree(shadow);
+ drm_client_framebuffer_delete(fb_helper->buffer);
+
+ drm_client_release(&fb_helper->client);
+ drm_fb_helper_unprepare(fb_helper);
+ kfree(fb_helper);
+ }
+
+ static const struct fb_ops drm_fbdev_ttm_fb_ops = {
+ .owner = THIS_MODULE,
+ .fb_open = drm_fbdev_ttm_fb_open,
+ .fb_release = drm_fbdev_ttm_fb_release,
+ FB_DEFAULT_DEFERRED_OPS(drm_fbdev_ttm),
+ DRM_FB_HELPER_DEFAULT_OPS,
+ .fb_destroy = drm_fbdev_ttm_fb_destroy,
+ };
+
+ /*
+ * This function uses the client API to create a framebuffer backed by a dumb buffer.
+ */
+ static int drm_fbdev_ttm_helper_fb_probe(struct drm_fb_helper *fb_helper,
+ struct drm_fb_helper_surface_size *sizes)
+ {
+ struct drm_client_dev *client = &fb_helper->client;
+ struct drm_device *dev = fb_helper->dev;
+ struct drm_client_buffer *buffer;
+ struct fb_info *info;
+ size_t screen_size;
+ void *screen_buffer;
+ u32 format;
+ int ret;
+
+ drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
+ sizes->surface_width, sizes->surface_height,
+ sizes->surface_bpp);
+
++ format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
++ sizes->surface_depth);
+ buffer = drm_client_framebuffer_create(client, sizes->surface_width,
+ sizes->surface_height, format);
+ if (IS_ERR(buffer))
+ return PTR_ERR(buffer);
+
+ fb_helper->buffer = buffer;
+ fb_helper->fb = buffer->fb;
+
+ screen_size = buffer->gem->size;
+ screen_buffer = vzalloc(screen_size);
+ if (!screen_buffer) {
+ ret = -ENOMEM;
+ goto err_drm_client_framebuffer_delete;
+ }
+
+ info = drm_fb_helper_alloc_info(fb_helper);
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
+ goto err_vfree;
+ }
+
+ drm_fb_helper_fill_info(info, fb_helper, sizes);
+
+ info->fbops = &drm_fbdev_ttm_fb_ops;
+
+ /* screen */
+ info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
+ info->screen_buffer = screen_buffer;
+ info->fix.smem_len = screen_size;
+
+ /* deferred I/O */
+ fb_helper->fbdefio.delay = HZ / 20;
+ fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
+
+ info->fbdefio = &fb_helper->fbdefio;
+ ret = fb_deferred_io_init(info);
+ if (ret)
+ goto err_drm_fb_helper_release_info;
+
+ return 0;
+
+ err_drm_fb_helper_release_info:
+ drm_fb_helper_release_info(fb_helper);
+ err_vfree:
+ vfree(screen_buffer);
+ err_drm_client_framebuffer_delete:
+ fb_helper->fb = NULL;
+ fb_helper->buffer = NULL;
+ drm_client_framebuffer_delete(buffer);
+ return ret;
+ }
+
+ static void drm_fbdev_ttm_damage_blit_real(struct drm_fb_helper *fb_helper,
+ struct drm_clip_rect *clip,
+ struct iosys_map *dst)
+ {
+ struct drm_framebuffer *fb = fb_helper->fb;
+ size_t offset = clip->y1 * fb->pitches[0];
+ size_t len = clip->x2 - clip->x1;
+ unsigned int y;
+ void *src;
+
+ switch (drm_format_info_bpp(fb->format, 0)) {
+ case 1:
+ offset += clip->x1 / 8;
+ len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
+ break;
+ case 2:
+ offset += clip->x1 / 4;
+ len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
+ break;
+ case 4:
+ offset += clip->x1 / 2;
+ len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
+ break;
+ default:
+ offset += clip->x1 * fb->format->cpp[0];
+ len *= fb->format->cpp[0];
+ break;
+ }
+
+ src = fb_helper->info->screen_buffer + offset;
+ iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
+
+ for (y = clip->y1; y < clip->y2; y++) {
+ iosys_map_memcpy_to(dst, 0, src, len);
+ iosys_map_incr(dst, fb->pitches[0]);
+ src += fb->pitches[0];
+ }
+ }
+
+ static int drm_fbdev_ttm_damage_blit(struct drm_fb_helper *fb_helper,
+ struct drm_clip_rect *clip)
+ {
+ struct drm_client_buffer *buffer = fb_helper->buffer;
+ struct iosys_map map, dst;
+ int ret;
+
+ /*
+ * We have to pin the client buffer to its current location while
+ * flushing the shadow buffer. In the general case, concurrent
+ * modesetting operations could try to move the buffer and would
+ * fail. The modeset has to be serialized by acquiring the reservation
+ * object of the underlying BO here.
+ *
+ * For fbdev emulation, we only have to protect against fbdev modeset
+ * operations. Nothing else will involve the client buffer's BO. So it
+ * is sufficient to acquire struct drm_fb_helper.lock here.
+ */
+ mutex_lock(&fb_helper->lock);
+
+ ret = drm_client_buffer_vmap_local(buffer, &map);
+ if (ret)
+ goto out;
+
+ dst = map;
+ drm_fbdev_ttm_damage_blit_real(fb_helper, clip, &dst);
+
+ drm_client_buffer_vunmap_local(buffer);
+
+ out:
+ mutex_unlock(&fb_helper->lock);
+
+ return ret;
+ }
+
+ static int drm_fbdev_ttm_helper_fb_dirty(struct drm_fb_helper *helper,
+ struct drm_clip_rect *clip)
+ {
+ struct drm_device *dev = helper->dev;
+ int ret;
+
+ /* Call damage handlers only if necessary */
+ if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
+ return 0;
+
+ ret = drm_fbdev_ttm_damage_blit(helper, clip);
+ if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
+ return ret;
+
+ if (helper->fb->funcs->dirty) {
+ ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
+ if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
+ return ret;
+ }
+
+ return 0;
+ }
+
+ static const struct drm_fb_helper_funcs drm_fbdev_ttm_helper_funcs = {
+ .fb_probe = drm_fbdev_ttm_helper_fb_probe,
+ .fb_dirty = drm_fbdev_ttm_helper_fb_dirty,
+ };
+
+ static void drm_fbdev_ttm_client_unregister(struct drm_client_dev *client)
+ {
+ struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+ if (fb_helper->info) {
+ drm_fb_helper_unregister_info(fb_helper);
+ } else {
+ drm_client_release(&fb_helper->client);
+ drm_fb_helper_unprepare(fb_helper);
+ kfree(fb_helper);
+ }
+ }
+
+ static int drm_fbdev_ttm_client_restore(struct drm_client_dev *client)
+ {
+ drm_fb_helper_lastclose(client->dev);
+
+ return 0;
+ }
+
+ static int drm_fbdev_ttm_client_hotplug(struct drm_client_dev *client)
+ {
+ struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+ struct drm_device *dev = client->dev;
+ int ret;
+
+ if (dev->fb_helper)
+ return drm_fb_helper_hotplug_event(dev->fb_helper);
+
+ ret = drm_fb_helper_init(dev, fb_helper);
+ if (ret)
+ goto err_drm_err;
+
+ if (!drm_drv_uses_atomic_modeset(dev))
+ drm_helper_disable_unused_functions(dev);
+
+ ret = drm_fb_helper_initial_config(fb_helper);
+ if (ret)
+ goto err_drm_fb_helper_fini;
+
+ return 0;
+
+ err_drm_fb_helper_fini:
+ drm_fb_helper_fini(fb_helper);
+ err_drm_err:
+ drm_err(dev, "fbdev: Failed to setup emulation (ret=%d)\n", ret);
+ return ret;
+ }
+
+ static const struct drm_client_funcs drm_fbdev_ttm_client_funcs = {
+ .owner = THIS_MODULE,
+ .unregister = drm_fbdev_ttm_client_unregister,
+ .restore = drm_fbdev_ttm_client_restore,
+ .hotplug = drm_fbdev_ttm_client_hotplug,
+ };
+
+ /**
+ * drm_fbdev_ttm_setup() - Setup fbdev emulation for TTM-based drivers
+ * @dev: DRM device
+ * @preferred_bpp: Preferred bits per pixel for the device.
+ *
+ * This function sets up fbdev emulation for TTM-based drivers that support
+ * dumb buffers with a virtual address and that can be mmap'ed.
+ * drm_fbdev_ttm_setup() shall be called after the DRM driver registered
+ * the new DRM device with drm_dev_register().
+ *
+ * Restore, hotplug events and teardown are all taken care of. Drivers that do
+ * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
+ * Simple drivers might use drm_mode_config_helper_suspend().
+ *
+ * In order to provide fixed mmap-able memory ranges, fbdev emulation
+ * uses a shadow buffer in system memory. The implementation blits the shadow
+ * fbdev buffer onto the real buffer in regular intervals.
+ *
+ * This function is safe to call even when there are no connectors present.
+ * Setup will be retried on the next hotplug event.
+ *
+ * The fbdev is destroyed by drm_dev_unregister().
+ */
+ void drm_fbdev_ttm_setup(struct drm_device *dev, unsigned int preferred_bpp)
+ {
+ struct drm_fb_helper *fb_helper;
+ int ret;
+
+ drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
+ drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
+
+ fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
+ if (!fb_helper)
+ return;
+ drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_ttm_helper_funcs);
+
+ ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_ttm_client_funcs);
+ if (ret) {
+ drm_err(dev, "Failed to register client: %d\n", ret);
+ goto err_drm_client_init;
+ }
+
+ drm_client_register(&fb_helper->client);
+
+ return;
+
+ err_drm_client_init:
+ drm_fb_helper_unprepare(fb_helper);
+ kfree(fb_helper);
+ return;
+ }
+ EXPORT_SYMBOL(drm_fbdev_ttm_setup);
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