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