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