1 // SPDX-License-Identifier: MIT 2 3 #include <linux/fb.h> 4 5 #include <drm/drm_crtc_helper.h> 6 #include <drm/drm_drv.h> 7 #include <drm/drm_fb_dma_helper.h> 8 #include <drm/drm_fb_helper.h> 9 #include <drm/drm_framebuffer.h> 10 #include <drm/drm_gem_dma_helper.h> 11 12 #include <drm/drm_fbdev_dma.h> 13 14 /* 15 * struct fb_ops 16 */ 17 18 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user) 19 { 20 struct drm_fb_helper *fb_helper = info->par; 21 22 /* No need to take a ref for fbcon because it unbinds on unregister */ 23 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 24 return -ENODEV; 25 26 return 0; 27 } 28 29 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 30 { 31 struct drm_fb_helper *fb_helper = info->par; 32 33 if (user) 34 module_put(fb_helper->dev->driver->fops->owner); 35 36 return 0; 37 } 38 39 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma, 40 drm_fb_helper_damage_range, 41 drm_fb_helper_damage_area); 42 43 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 44 { 45 struct drm_fb_helper *fb_helper = info->par; 46 struct drm_framebuffer *fb = fb_helper->fb; 47 struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0); 48 49 if (!dma->map_noncoherent) 50 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 51 52 return fb_deferred_io_mmap(info, vma); 53 } 54 55 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 56 { 57 struct drm_fb_helper *fb_helper = info->par; 58 59 if (!fb_helper->dev) 60 return; 61 62 fb_deferred_io_cleanup(info); 63 drm_fb_helper_fini(fb_helper); 64 65 drm_client_buffer_vunmap(fb_helper->buffer); 66 drm_client_framebuffer_delete(fb_helper->buffer); 67 drm_client_release(&fb_helper->client); 68 drm_fb_helper_unprepare(fb_helper); 69 kfree(fb_helper); 70 } 71 72 static const struct fb_ops drm_fbdev_dma_fb_ops = { 73 .owner = THIS_MODULE, 74 .fb_open = drm_fbdev_dma_fb_open, 75 .fb_release = drm_fbdev_dma_fb_release, 76 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma), 77 DRM_FB_HELPER_DEFAULT_OPS, 78 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma), 79 .fb_mmap = drm_fbdev_dma_fb_mmap, 80 .fb_destroy = drm_fbdev_dma_fb_destroy, 81 }; 82 83 /* 84 * struct drm_fb_helper 85 */ 86 87 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 88 struct drm_fb_helper_surface_size *sizes) 89 { 90 struct drm_client_dev *client = &fb_helper->client; 91 struct drm_device *dev = fb_helper->dev; 92 struct drm_client_buffer *buffer; 93 struct drm_gem_dma_object *dma_obj; 94 struct drm_framebuffer *fb; 95 struct fb_info *info; 96 u32 format; 97 struct iosys_map map; 98 int ret; 99 100 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 101 sizes->surface_width, sizes->surface_height, 102 sizes->surface_bpp); 103 104 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth); 105 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 106 sizes->surface_height, format); 107 if (IS_ERR(buffer)) 108 return PTR_ERR(buffer); 109 dma_obj = to_drm_gem_dma_obj(buffer->gem); 110 111 fb = buffer->fb; 112 113 ret = drm_client_buffer_vmap(buffer, &map); 114 if (ret) { 115 goto err_drm_client_buffer_delete; 116 } else if (drm_WARN_ON(dev, map.is_iomem)) { 117 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 118 goto err_drm_client_buffer_delete; 119 } 120 121 fb_helper->buffer = buffer; 122 fb_helper->fb = fb; 123 124 info = drm_fb_helper_alloc_info(fb_helper); 125 if (IS_ERR(info)) { 126 ret = PTR_ERR(info); 127 goto err_drm_client_buffer_vunmap; 128 } 129 130 drm_fb_helper_fill_info(info, fb_helper, sizes); 131 132 info->fbops = &drm_fbdev_dma_fb_ops; 133 134 /* screen */ 135 info->flags |= FBINFO_VIRTFB; /* system memory */ 136 if (dma_obj->map_noncoherent) 137 info->flags |= FBINFO_READS_FAST; /* signal caching */ 138 info->screen_size = sizes->surface_height * fb->pitches[0]; 139 info->screen_buffer = map.vaddr; 140 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 141 info->fix.smem_len = info->screen_size; 142 143 /* deferred I/O */ 144 fb_helper->fbdefio.delay = HZ / 20; 145 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 146 147 info->fbdefio = &fb_helper->fbdefio; 148 ret = fb_deferred_io_init(info); 149 if (ret) 150 goto err_drm_fb_helper_release_info; 151 152 return 0; 153 154 err_drm_fb_helper_release_info: 155 drm_fb_helper_release_info(fb_helper); 156 err_drm_client_buffer_vunmap: 157 fb_helper->fb = NULL; 158 fb_helper->buffer = NULL; 159 drm_client_buffer_vunmap(buffer); 160 err_drm_client_buffer_delete: 161 drm_client_framebuffer_delete(buffer); 162 return ret; 163 } 164 165 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper, 166 struct drm_clip_rect *clip) 167 { 168 struct drm_device *dev = helper->dev; 169 int ret; 170 171 /* Call damage handlers only if necessary */ 172 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 173 return 0; 174 175 if (helper->fb->funcs->dirty) { 176 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 177 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 178 return ret; 179 } 180 181 return 0; 182 } 183 184 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 185 .fb_probe = drm_fbdev_dma_helper_fb_probe, 186 .fb_dirty = drm_fbdev_dma_helper_fb_dirty, 187 }; 188 189 /* 190 * struct drm_client_funcs 191 */ 192 193 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 194 { 195 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 196 197 if (fb_helper->info) { 198 drm_fb_helper_unregister_info(fb_helper); 199 } else { 200 drm_client_release(&fb_helper->client); 201 drm_fb_helper_unprepare(fb_helper); 202 kfree(fb_helper); 203 } 204 } 205 206 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 207 { 208 drm_fb_helper_lastclose(client->dev); 209 210 return 0; 211 } 212 213 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 214 { 215 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 216 struct drm_device *dev = client->dev; 217 int ret; 218 219 if (dev->fb_helper) 220 return drm_fb_helper_hotplug_event(dev->fb_helper); 221 222 ret = drm_fb_helper_init(dev, fb_helper); 223 if (ret) 224 goto err_drm_err; 225 226 if (!drm_drv_uses_atomic_modeset(dev)) 227 drm_helper_disable_unused_functions(dev); 228 229 ret = drm_fb_helper_initial_config(fb_helper); 230 if (ret) 231 goto err_drm_fb_helper_fini; 232 233 return 0; 234 235 err_drm_fb_helper_fini: 236 drm_fb_helper_fini(fb_helper); 237 err_drm_err: 238 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 239 return ret; 240 } 241 242 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 243 .owner = THIS_MODULE, 244 .unregister = drm_fbdev_dma_client_unregister, 245 .restore = drm_fbdev_dma_client_restore, 246 .hotplug = drm_fbdev_dma_client_hotplug, 247 }; 248 249 /** 250 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 251 * @dev: DRM device 252 * @preferred_bpp: Preferred bits per pixel for the device. 253 * 32 is used if this is zero. 254 * 255 * This function sets up fbdev emulation for GEM DMA drivers that support 256 * dumb buffers with a virtual address and that can be mmap'ed. 257 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 258 * the new DRM device with drm_dev_register(). 259 * 260 * Restore, hotplug events and teardown are all taken care of. Drivers that do 261 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 262 * Simple drivers might use drm_mode_config_helper_suspend(). 263 * 264 * This function is safe to call even when there are no connectors present. 265 * Setup will be retried on the next hotplug event. 266 * 267 * The fbdev is destroyed by drm_dev_unregister(). 268 */ 269 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 270 { 271 struct drm_fb_helper *fb_helper; 272 int ret; 273 274 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 275 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 276 277 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 278 if (!fb_helper) 279 return; 280 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 281 282 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 283 if (ret) { 284 drm_err(dev, "Failed to register client: %d\n", ret); 285 goto err_drm_client_init; 286 } 287 288 drm_client_register(&fb_helper->client); 289 290 return; 291 292 err_drm_client_init: 293 drm_fb_helper_unprepare(fb_helper); 294 kfree(fb_helper); 295 } 296 EXPORT_SYMBOL(drm_fbdev_dma_setup); 297