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_driver_legacy_fb_format(dev, sizes->surface_bpp, 105 sizes->surface_depth); 106 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 107 sizes->surface_height, format); 108 if (IS_ERR(buffer)) 109 return PTR_ERR(buffer); 110 dma_obj = to_drm_gem_dma_obj(buffer->gem); 111 112 fb = buffer->fb; 113 114 ret = drm_client_buffer_vmap(buffer, &map); 115 if (ret) { 116 goto err_drm_client_buffer_delete; 117 } else if (drm_WARN_ON(dev, map.is_iomem)) { 118 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 119 goto err_drm_client_buffer_delete; 120 } 121 122 fb_helper->buffer = buffer; 123 fb_helper->fb = fb; 124 125 info = drm_fb_helper_alloc_info(fb_helper); 126 if (IS_ERR(info)) { 127 ret = PTR_ERR(info); 128 goto err_drm_client_buffer_vunmap; 129 } 130 131 drm_fb_helper_fill_info(info, fb_helper, sizes); 132 133 info->fbops = &drm_fbdev_dma_fb_ops; 134 135 /* screen */ 136 info->flags |= FBINFO_VIRTFB; /* system memory */ 137 if (dma_obj->map_noncoherent) 138 info->flags |= FBINFO_READS_FAST; /* signal caching */ 139 info->screen_size = sizes->surface_height * fb->pitches[0]; 140 info->screen_buffer = map.vaddr; 141 if (!(info->flags & FBINFO_HIDE_SMEM_START)) { 142 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer))) 143 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 144 } 145 info->fix.smem_len = info->screen_size; 146 147 /* deferred I/O */ 148 fb_helper->fbdefio.delay = HZ / 20; 149 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 150 151 info->fbdefio = &fb_helper->fbdefio; 152 ret = fb_deferred_io_init(info); 153 if (ret) 154 goto err_drm_fb_helper_release_info; 155 156 return 0; 157 158 err_drm_fb_helper_release_info: 159 drm_fb_helper_release_info(fb_helper); 160 err_drm_client_buffer_vunmap: 161 fb_helper->fb = NULL; 162 fb_helper->buffer = NULL; 163 drm_client_buffer_vunmap(buffer); 164 err_drm_client_buffer_delete: 165 drm_client_framebuffer_delete(buffer); 166 return ret; 167 } 168 169 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper, 170 struct drm_clip_rect *clip) 171 { 172 struct drm_device *dev = helper->dev; 173 int ret; 174 175 /* Call damage handlers only if necessary */ 176 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 177 return 0; 178 179 if (helper->fb->funcs->dirty) { 180 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 181 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 182 return ret; 183 } 184 185 return 0; 186 } 187 188 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 189 .fb_probe = drm_fbdev_dma_helper_fb_probe, 190 .fb_dirty = drm_fbdev_dma_helper_fb_dirty, 191 }; 192 193 /* 194 * struct drm_client_funcs 195 */ 196 197 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 198 { 199 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 200 201 if (fb_helper->info) { 202 drm_fb_helper_unregister_info(fb_helper); 203 } else { 204 drm_client_release(&fb_helper->client); 205 drm_fb_helper_unprepare(fb_helper); 206 kfree(fb_helper); 207 } 208 } 209 210 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 211 { 212 drm_fb_helper_lastclose(client->dev); 213 214 return 0; 215 } 216 217 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 218 { 219 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 220 struct drm_device *dev = client->dev; 221 int ret; 222 223 if (dev->fb_helper) 224 return drm_fb_helper_hotplug_event(dev->fb_helper); 225 226 ret = drm_fb_helper_init(dev, fb_helper); 227 if (ret) 228 goto err_drm_err; 229 230 if (!drm_drv_uses_atomic_modeset(dev)) 231 drm_helper_disable_unused_functions(dev); 232 233 ret = drm_fb_helper_initial_config(fb_helper); 234 if (ret) 235 goto err_drm_fb_helper_fini; 236 237 return 0; 238 239 err_drm_fb_helper_fini: 240 drm_fb_helper_fini(fb_helper); 241 err_drm_err: 242 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 243 return ret; 244 } 245 246 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 247 .owner = THIS_MODULE, 248 .unregister = drm_fbdev_dma_client_unregister, 249 .restore = drm_fbdev_dma_client_restore, 250 .hotplug = drm_fbdev_dma_client_hotplug, 251 }; 252 253 /** 254 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 255 * @dev: DRM device 256 * @preferred_bpp: Preferred bits per pixel for the device. 257 * 32 is used if this is zero. 258 * 259 * This function sets up fbdev emulation for GEM DMA drivers that support 260 * dumb buffers with a virtual address and that can be mmap'ed. 261 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 262 * the new DRM device with drm_dev_register(). 263 * 264 * Restore, hotplug events and teardown are all taken care of. Drivers that do 265 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 266 * Simple drivers might use drm_mode_config_helper_suspend(). 267 * 268 * This function is safe to call even when there are no connectors present. 269 * Setup will be retried on the next hotplug event. 270 * 271 * The fbdev is destroyed by drm_dev_unregister(). 272 */ 273 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 274 { 275 struct drm_fb_helper *fb_helper; 276 int ret; 277 278 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 279 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 280 281 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 282 if (!fb_helper) 283 return; 284 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 285 286 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 287 if (ret) { 288 drm_err(dev, "Failed to register client: %d\n", ret); 289 goto err_drm_client_init; 290 } 291 292 drm_client_register(&fb_helper->client); 293 294 return; 295 296 err_drm_client_init: 297 drm_fb_helper_unprepare(fb_helper); 298 kfree(fb_helper); 299 } 300 EXPORT_SYMBOL(drm_fbdev_dma_setup); 301