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_helper.h> 8 #include <drm/drm_framebuffer.h> 9 #include <drm/drm_gem_dma_helper.h> 10 11 #include <drm/drm_fbdev_dma.h> 12 13 /* 14 * struct fb_ops 15 */ 16 17 #ifdef __linux__ 18 19 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user) 20 { 21 struct drm_fb_helper *fb_helper = info->par; 22 23 /* No need to take a ref for fbcon because it unbinds on unregister */ 24 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 25 return -ENODEV; 26 27 return 0; 28 } 29 30 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 31 { 32 struct drm_fb_helper *fb_helper = info->par; 33 34 if (user) 35 module_put(fb_helper->dev->driver->fops->owner); 36 37 return 0; 38 } 39 40 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 41 { 42 struct drm_fb_helper *fb_helper = info->par; 43 44 if (!fb_helper->dev) 45 return; 46 47 drm_fb_helper_fini(fb_helper); 48 49 drm_client_buffer_vunmap(fb_helper->buffer); 50 drm_client_framebuffer_delete(fb_helper->buffer); 51 drm_client_release(&fb_helper->client); 52 drm_fb_helper_unprepare(fb_helper); 53 kfree(fb_helper); 54 } 55 56 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 57 { 58 struct drm_fb_helper *fb_helper = info->par; 59 60 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma); 61 } 62 63 #endif /* __linux__ */ 64 65 static const struct fb_ops drm_fbdev_dma_fb_ops = { 66 #ifdef notyet 67 .owner = THIS_MODULE, 68 .fb_open = drm_fbdev_dma_fb_open, 69 .fb_release = drm_fbdev_dma_fb_release, 70 __FB_DEFAULT_DMAMEM_OPS_RDWR, 71 DRM_FB_HELPER_DEFAULT_OPS, 72 __FB_DEFAULT_DMAMEM_OPS_DRAW, 73 .fb_mmap = drm_fbdev_dma_fb_mmap, 74 .fb_destroy = drm_fbdev_dma_fb_destroy, 75 #else 76 DRM_FB_HELPER_DEFAULT_OPS, 77 #endif 78 }; 79 80 /* 81 * struct drm_fb_helper 82 */ 83 84 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 85 struct drm_fb_helper_surface_size *sizes) 86 { 87 struct drm_client_dev *client = &fb_helper->client; 88 struct drm_device *dev = fb_helper->dev; 89 struct drm_client_buffer *buffer; 90 struct drm_gem_dma_object *dma_obj; 91 struct drm_framebuffer *fb; 92 struct fb_info *info; 93 u32 format; 94 struct iosys_map map; 95 int ret; 96 97 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 98 sizes->surface_width, sizes->surface_height, 99 sizes->surface_bpp); 100 101 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth); 102 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 103 sizes->surface_height, format); 104 if (IS_ERR(buffer)) 105 return PTR_ERR(buffer); 106 dma_obj = to_drm_gem_dma_obj(buffer->gem); 107 108 fb = buffer->fb; 109 if (drm_WARN_ON(dev, fb->funcs->dirty)) { 110 ret = -ENODEV; /* damage handling not supported; use generic emulation */ 111 goto err_drm_client_buffer_delete; 112 } 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 = buffer->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 return 0; 148 149 err_drm_client_buffer_vunmap: 150 fb_helper->fb = NULL; 151 fb_helper->buffer = NULL; 152 drm_client_buffer_vunmap(buffer); 153 err_drm_client_buffer_delete: 154 drm_client_framebuffer_delete(buffer); 155 return ret; 156 } 157 158 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 159 .fb_probe = drm_fbdev_dma_helper_fb_probe, 160 }; 161 162 /* 163 * struct drm_client_funcs 164 */ 165 166 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 167 { 168 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 169 170 if (fb_helper->info) { 171 drm_fb_helper_unregister_info(fb_helper); 172 } else { 173 drm_client_release(&fb_helper->client); 174 drm_fb_helper_unprepare(fb_helper); 175 kfree(fb_helper); 176 } 177 } 178 179 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 180 { 181 drm_fb_helper_lastclose(client->dev); 182 183 return 0; 184 } 185 186 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 187 { 188 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 189 struct drm_device *dev = client->dev; 190 int ret; 191 192 if (dev->fb_helper) 193 return drm_fb_helper_hotplug_event(dev->fb_helper); 194 195 ret = drm_fb_helper_init(dev, fb_helper); 196 if (ret) 197 goto err_drm_err; 198 199 if (!drm_drv_uses_atomic_modeset(dev)) 200 drm_helper_disable_unused_functions(dev); 201 202 ret = drm_fb_helper_initial_config(fb_helper); 203 if (ret) 204 goto err_drm_fb_helper_fini; 205 206 return 0; 207 208 err_drm_fb_helper_fini: 209 drm_fb_helper_fini(fb_helper); 210 err_drm_err: 211 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 212 return ret; 213 } 214 215 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 216 .owner = THIS_MODULE, 217 .unregister = drm_fbdev_dma_client_unregister, 218 .restore = drm_fbdev_dma_client_restore, 219 .hotplug = drm_fbdev_dma_client_hotplug, 220 }; 221 222 /** 223 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 224 * @dev: DRM device 225 * @preferred_bpp: Preferred bits per pixel for the device. 226 * 32 is used if this is zero. 227 * 228 * This function sets up fbdev emulation for GEM DMA drivers that support 229 * dumb buffers with a virtual address and that can be mmap'ed. 230 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 231 * the new DRM device with drm_dev_register(). 232 * 233 * Restore, hotplug events and teardown are all taken care of. Drivers that do 234 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 235 * Simple drivers might use drm_mode_config_helper_suspend(). 236 * 237 * This function is safe to call even when there are no connectors present. 238 * Setup will be retried on the next hotplug event. 239 * 240 * The fbdev is destroyed by drm_dev_unregister(). 241 */ 242 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 243 { 244 struct drm_fb_helper *fb_helper; 245 int ret; 246 247 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 248 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 249 250 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 251 if (!fb_helper) 252 return; 253 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 254 255 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 256 if (ret) { 257 drm_err(dev, "Failed to register client: %d\n", ret); 258 goto err_drm_client_init; 259 } 260 261 drm_client_register(&fb_helper->client); 262 263 return; 264 265 err_drm_client_init: 266 drm_fb_helper_unprepare(fb_helper); 267 kfree(fb_helper); 268 } 269 EXPORT_SYMBOL(drm_fbdev_dma_setup); 270