1 // SPDX-License-Identifier: MIT 2 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> 8 9 #include <drm/drm_fbdev_dma.h> 10 11 /* 12 * struct fb_ops 13 */ 14 15 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user) 16 { 17 struct drm_fb_helper *fb_helper = info->par; 18 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)) 21 return -ENODEV; 22 23 return 0; 24 } 25 26 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 27 { 28 struct drm_fb_helper *fb_helper = info->par; 29 30 if (user) 31 module_put(fb_helper->dev->driver->fops->owner); 32 33 return 0; 34 } 35 36 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 37 { 38 struct drm_fb_helper *fb_helper = info->par; 39 40 if (!fb_helper->dev) 41 return; 42 43 drm_fb_helper_fini(fb_helper); 44 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); 49 kfree(fb_helper); 50 } 51 52 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 53 { 54 struct drm_fb_helper *fb_helper = info->par; 55 struct drm_device *dev = fb_helper->dev; 56 57 if (drm_WARN_ON_ONCE(dev, !fb_helper->dev->driver->gem_prime_mmap)) 58 return -ENODEV; 59 60 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma); 61 } 62 63 static const struct fb_ops drm_fbdev_dma_fb_ops = { 64 .owner = THIS_MODULE, 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, 75 }; 76 77 /* 78 * struct drm_fb_helper 79 */ 80 81 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 82 struct drm_fb_helper_surface_size *sizes) 83 { 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; 89 struct fb_info *info; 90 u32 format; 91 struct iosys_map map; 92 int ret; 93 94 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 95 sizes->surface_width, sizes->surface_height, 96 sizes->surface_bpp); 97 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); 101 if (IS_ERR(buffer)) 102 return PTR_ERR(buffer); 103 dma_obj = to_drm_gem_dma_obj(buffer->gem); 104 105 fb = buffer->fb; 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; 109 } 110 111 ret = drm_client_buffer_vmap(buffer, &map); 112 if (ret) { 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; 117 } 118 119 fb_helper->buffer = buffer; 120 fb_helper->fb = buffer->fb; 121 122 info = drm_fb_helper_alloc_info(fb_helper); 123 if (IS_ERR(info)) { 124 ret = PTR_ERR(info); 125 goto err_drm_client_buffer_vunmap; 126 } 127 128 drm_fb_helper_fill_info(info, fb_helper, sizes); 129 130 info->fbops = &drm_fbdev_dma_fb_ops; 131 info->flags = FBINFO_DEFAULT; 132 133 /* screen */ 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; 140 141 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM) 142 /* 143 * Shamelessly leak the physical address to user-space. 144 */ 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)); 147 #endif 148 149 return 0; 150 151 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); 157 return ret; 158 } 159 160 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 161 .fb_probe = drm_fbdev_dma_helper_fb_probe, 162 }; 163 164 /* 165 * struct drm_client_funcs 166 */ 167 168 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 169 { 170 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 171 172 if (fb_helper->info) { 173 drm_fb_helper_unregister_info(fb_helper); 174 } else { 175 drm_client_release(&fb_helper->client); 176 drm_fb_helper_unprepare(fb_helper); 177 kfree(fb_helper); 178 } 179 } 180 181 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 182 { 183 drm_fb_helper_lastclose(client->dev); 184 185 return 0; 186 } 187 188 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 189 { 190 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 191 struct drm_device *dev = client->dev; 192 int ret; 193 194 if (dev->fb_helper) 195 return drm_fb_helper_hotplug_event(dev->fb_helper); 196 197 ret = drm_fb_helper_init(dev, fb_helper); 198 if (ret) 199 goto err_drm_err; 200 201 if (!drm_drv_uses_atomic_modeset(dev)) 202 drm_helper_disable_unused_functions(dev); 203 204 ret = drm_fb_helper_initial_config(fb_helper); 205 if (ret) 206 goto err_drm_fb_helper_fini; 207 208 return 0; 209 210 err_drm_fb_helper_fini: 211 drm_fb_helper_fini(fb_helper); 212 err_drm_err: 213 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 214 return ret; 215 } 216 217 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, 222 }; 223 224 /** 225 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 226 * @dev: DRM device 227 * @preferred_bpp: Preferred bits per pixel for the device. 228 * @dev->mode_config.preferred_depth is used if this is zero. 229 * 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(). 234 * 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(). 238 * 239 * This function is safe to call even when there are no connectors present. 240 * Setup will be retried on the next hotplug event. 241 * 242 * The fbdev is destroyed by drm_dev_unregister(). 243 */ 244 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 245 { 246 struct drm_fb_helper *fb_helper; 247 int ret; 248 249 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 250 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 251 252 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 253 if (!fb_helper) 254 return; 255 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 256 257 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 258 if (ret) { 259 drm_err(dev, "Failed to register client: %d\n", ret); 260 goto err_drm_client_init; 261 } 262 263 ret = drm_fbdev_dma_client_hotplug(&fb_helper->client); 264 if (ret) 265 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret); 266 267 drm_client_register(&fb_helper->client); 268 269 return; 270 271 err_drm_client_init: 272 drm_fb_helper_unprepare(fb_helper); 273 kfree(fb_helper); 274 } 275 EXPORT_SYMBOL(drm_fbdev_dma_setup); 276