1 // SPDX-License-Identifier: MIT
3 #include <drm/drm_crtc_helper.h>
4 #include <drm/drm_drv.h>
5 #include <drm/drm_fb_helper.h>
6 #include <drm/drm_framebuffer.h>
7 #include <drm/drm_gem_dma_helper.h>
9 #include <drm/drm_fbdev_dma.h>
15 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
17 struct drm_fb_helper *fb_helper = info->par;
19 /* No need to take a ref for fbcon because it unbinds on unregister */
20 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
26 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
28 struct drm_fb_helper *fb_helper = info->par;
31 module_put(fb_helper->dev->driver->fops->owner);
36 static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
38 struct drm_fb_helper *fb_helper = info->par;
43 drm_fb_helper_fini(fb_helper);
45 drm_client_buffer_vunmap(fb_helper->buffer);
46 drm_client_framebuffer_delete(fb_helper->buffer);
47 drm_client_release(&fb_helper->client);
48 drm_fb_helper_unprepare(fb_helper);
52 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
54 struct drm_fb_helper *fb_helper = info->par;
55 struct drm_device *dev = fb_helper->dev;
57 if (drm_WARN_ON_ONCE(dev, !fb_helper->dev->driver->gem_prime_mmap))
60 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
63 static const struct fb_ops drm_fbdev_dma_fb_ops = {
65 .fb_open = drm_fbdev_dma_fb_open,
66 .fb_release = drm_fbdev_dma_fb_release,
67 .fb_read = drm_fb_helper_sys_read,
68 .fb_write = drm_fb_helper_sys_write,
69 DRM_FB_HELPER_DEFAULT_OPS,
70 .fb_fillrect = drm_fb_helper_sys_fillrect,
71 .fb_copyarea = drm_fb_helper_sys_copyarea,
72 .fb_imageblit = drm_fb_helper_sys_imageblit,
73 .fb_destroy = drm_fbdev_dma_fb_destroy,
74 .fb_mmap = drm_fbdev_dma_fb_mmap,
78 * struct drm_fb_helper
81 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,
82 struct drm_fb_helper_surface_size *sizes)
84 struct drm_client_dev *client = &fb_helper->client;
85 struct drm_device *dev = fb_helper->dev;
86 struct drm_client_buffer *buffer;
87 struct drm_gem_dma_object *dma_obj;
88 struct drm_framebuffer *fb;
94 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
95 sizes->surface_width, sizes->surface_height,
98 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
99 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
100 sizes->surface_height, format);
102 return PTR_ERR(buffer);
103 dma_obj = to_drm_gem_dma_obj(buffer->gem);
106 if (drm_WARN_ON(dev, fb->funcs->dirty)) {
107 ret = -ENODEV; /* damage handling not supported; use generic emulation */
108 goto err_drm_client_buffer_delete;
111 ret = drm_client_buffer_vmap(buffer, &map);
113 goto err_drm_client_buffer_delete;
114 } else if (drm_WARN_ON(dev, map.is_iomem)) {
115 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
116 goto err_drm_client_buffer_delete;
119 fb_helper->buffer = buffer;
120 fb_helper->fb = buffer->fb;
122 info = drm_fb_helper_alloc_info(fb_helper);
125 goto err_drm_client_buffer_vunmap;
128 drm_fb_helper_fill_info(info, fb_helper, sizes);
130 info->fbops = &drm_fbdev_dma_fb_ops;
131 info->flags = FBINFO_DEFAULT;
134 info->flags |= FBINFO_VIRTFB; /* system memory */
135 if (dma_obj->map_noncoherent)
136 info->flags |= FBINFO_READS_FAST; /* signal caching */
137 info->screen_size = sizes->surface_height * fb->pitches[0];
138 info->screen_buffer = map.vaddr;
139 info->fix.smem_len = info->screen_size;
141 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
143 * Shamelessly leak the physical address to user-space.
145 if (fb_helper->hint_leak_smem_start && !info->fix.smem_start)
146 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
151 err_drm_client_buffer_vunmap:
152 fb_helper->fb = NULL;
153 fb_helper->buffer = NULL;
154 drm_client_buffer_vunmap(buffer);
155 err_drm_client_buffer_delete:
156 drm_client_framebuffer_delete(buffer);
160 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
161 .fb_probe = drm_fbdev_dma_helper_fb_probe,
165 * struct drm_client_funcs
168 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client)
170 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
172 if (fb_helper->info) {
173 drm_fb_helper_unregister_info(fb_helper);
175 drm_client_release(&fb_helper->client);
176 drm_fb_helper_unprepare(fb_helper);
181 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client)
183 drm_fb_helper_lastclose(client->dev);
188 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client)
190 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
191 struct drm_device *dev = client->dev;
195 return drm_fb_helper_hotplug_event(dev->fb_helper);
197 ret = drm_fb_helper_init(dev, fb_helper);
201 if (!drm_drv_uses_atomic_modeset(dev))
202 drm_helper_disable_unused_functions(dev);
204 ret = drm_fb_helper_initial_config(fb_helper);
206 goto err_drm_fb_helper_fini;
210 err_drm_fb_helper_fini:
211 drm_fb_helper_fini(fb_helper);
213 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret);
217 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = {
218 .owner = THIS_MODULE,
219 .unregister = drm_fbdev_dma_client_unregister,
220 .restore = drm_fbdev_dma_client_restore,
221 .hotplug = drm_fbdev_dma_client_hotplug,
225 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers
227 * @preferred_bpp: Preferred bits per pixel for the device.
228 * @dev->mode_config.preferred_depth is used if this is zero.
230 * This function sets up fbdev emulation for GEM DMA drivers that support
231 * dumb buffers with a virtual address and that can be mmap'ed.
232 * drm_fbdev_dma_setup() shall be called after the DRM driver registered
233 * the new DRM device with drm_dev_register().
235 * Restore, hotplug events and teardown are all taken care of. Drivers that do
236 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
237 * Simple drivers might use drm_mode_config_helper_suspend().
239 * This function is safe to call even when there are no connectors present.
240 * Setup will be retried on the next hotplug event.
242 * The fbdev is destroyed by drm_dev_unregister().
244 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp)
246 struct drm_fb_helper *fb_helper;
249 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
250 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
252 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
255 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs);
257 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs);
259 drm_err(dev, "Failed to register client: %d\n", ret);
260 goto err_drm_client_init;
263 ret = drm_fbdev_dma_client_hotplug(&fb_helper->client);
265 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
267 drm_client_register(&fb_helper->client);
272 drm_fb_helper_unprepare(fb_helper);
275 EXPORT_SYMBOL(drm_fbdev_dma_setup);