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 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user) 18 { 19 struct drm_fb_helper *fb_helper = info->par; 20 21 /* No need to take a ref for fbcon because it unbinds on unregister */ 22 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 23 return -ENODEV; 24 25 return 0; 26 } 27 28 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 29 { 30 struct drm_fb_helper *fb_helper = info->par; 31 32 if (user) 33 module_put(fb_helper->dev->driver->fops->owner); 34 35 return 0; 36 } 37 38 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 39 { 40 struct drm_fb_helper *fb_helper = info->par; 41 42 if (!fb_helper->dev) 43 return; 44 45 drm_fb_helper_fini(fb_helper); 46 47 drm_client_buffer_vunmap(fb_helper->buffer); 48 drm_client_framebuffer_delete(fb_helper->buffer); 49 drm_client_release(&fb_helper->client); 50 drm_fb_helper_unprepare(fb_helper); 51 kfree(fb_helper); 52 } 53 54 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 55 { 56 struct drm_fb_helper *fb_helper = info->par; 57 struct drm_device *dev = fb_helper->dev; 58 59 if (drm_WARN_ON_ONCE(dev, !fb_helper->dev->driver->gem_prime_mmap)) 60 return -ENODEV; 61 62 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma); 63 } 64 65 static const struct fb_ops drm_fbdev_dma_fb_ops = { 66 .owner = THIS_MODULE, 67 .fb_open = drm_fbdev_dma_fb_open, 68 .fb_release = drm_fbdev_dma_fb_release, 69 __FB_DEFAULT_SYS_OPS_RDWR, 70 DRM_FB_HELPER_DEFAULT_OPS, 71 __FB_DEFAULT_SYS_OPS_DRAW, 72 .fb_mmap = drm_fbdev_dma_fb_mmap, 73 .fb_destroy = drm_fbdev_dma_fb_destroy, 74 }; 75 76 /* 77 * struct drm_fb_helper 78 */ 79 80 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 81 struct drm_fb_helper_surface_size *sizes) 82 { 83 struct drm_client_dev *client = &fb_helper->client; 84 struct drm_device *dev = fb_helper->dev; 85 struct drm_client_buffer *buffer; 86 struct drm_gem_dma_object *dma_obj; 87 struct drm_framebuffer *fb; 88 struct fb_info *info; 89 u32 format; 90 struct iosys_map map; 91 int ret; 92 93 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 94 sizes->surface_width, sizes->surface_height, 95 sizes->surface_bpp); 96 97 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth); 98 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 99 sizes->surface_height, format); 100 if (IS_ERR(buffer)) 101 return PTR_ERR(buffer); 102 dma_obj = to_drm_gem_dma_obj(buffer->gem); 103 104 fb = buffer->fb; 105 if (drm_WARN_ON(dev, fb->funcs->dirty)) { 106 ret = -ENODEV; /* damage handling not supported; use generic emulation */ 107 goto err_drm_client_buffer_delete; 108 } 109 110 ret = drm_client_buffer_vmap(buffer, &map); 111 if (ret) { 112 goto err_drm_client_buffer_delete; 113 } else if (drm_WARN_ON(dev, map.is_iomem)) { 114 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 115 goto err_drm_client_buffer_delete; 116 } 117 118 fb_helper->buffer = buffer; 119 fb_helper->fb = buffer->fb; 120 121 info = drm_fb_helper_alloc_info(fb_helper); 122 if (IS_ERR(info)) { 123 ret = PTR_ERR(info); 124 goto err_drm_client_buffer_vunmap; 125 } 126 127 drm_fb_helper_fill_info(info, fb_helper, sizes); 128 129 info->fbops = &drm_fbdev_dma_fb_ops; 130 info->flags = FBINFO_DEFAULT; 131 132 /* screen */ 133 info->flags |= FBINFO_VIRTFB; /* system memory */ 134 if (dma_obj->map_noncoherent) 135 info->flags |= FBINFO_READS_FAST; /* signal caching */ 136 info->screen_size = sizes->surface_height * fb->pitches[0]; 137 info->screen_buffer = map.vaddr; 138 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 139 info->fix.smem_len = info->screen_size; 140 141 return 0; 142 143 err_drm_client_buffer_vunmap: 144 fb_helper->fb = NULL; 145 fb_helper->buffer = NULL; 146 drm_client_buffer_vunmap(buffer); 147 err_drm_client_buffer_delete: 148 drm_client_framebuffer_delete(buffer); 149 return ret; 150 } 151 152 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 153 .fb_probe = drm_fbdev_dma_helper_fb_probe, 154 }; 155 156 /* 157 * struct drm_client_funcs 158 */ 159 160 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 161 { 162 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 163 164 if (fb_helper->info) { 165 drm_fb_helper_unregister_info(fb_helper); 166 } else { 167 drm_client_release(&fb_helper->client); 168 drm_fb_helper_unprepare(fb_helper); 169 kfree(fb_helper); 170 } 171 } 172 173 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 174 { 175 drm_fb_helper_lastclose(client->dev); 176 177 return 0; 178 } 179 180 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 181 { 182 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 183 struct drm_device *dev = client->dev; 184 int ret; 185 186 if (dev->fb_helper) 187 return drm_fb_helper_hotplug_event(dev->fb_helper); 188 189 ret = drm_fb_helper_init(dev, fb_helper); 190 if (ret) 191 goto err_drm_err; 192 193 if (!drm_drv_uses_atomic_modeset(dev)) 194 drm_helper_disable_unused_functions(dev); 195 196 ret = drm_fb_helper_initial_config(fb_helper); 197 if (ret) 198 goto err_drm_fb_helper_fini; 199 200 return 0; 201 202 err_drm_fb_helper_fini: 203 drm_fb_helper_fini(fb_helper); 204 err_drm_err: 205 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 206 return ret; 207 } 208 209 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 210 .owner = THIS_MODULE, 211 .unregister = drm_fbdev_dma_client_unregister, 212 .restore = drm_fbdev_dma_client_restore, 213 .hotplug = drm_fbdev_dma_client_hotplug, 214 }; 215 216 /** 217 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 218 * @dev: DRM device 219 * @preferred_bpp: Preferred bits per pixel for the device. 220 * 32 is used if this is zero. 221 * 222 * This function sets up fbdev emulation for GEM DMA drivers that support 223 * dumb buffers with a virtual address and that can be mmap'ed. 224 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 225 * the new DRM device with drm_dev_register(). 226 * 227 * Restore, hotplug events and teardown are all taken care of. Drivers that do 228 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 229 * Simple drivers might use drm_mode_config_helper_suspend(). 230 * 231 * This function is safe to call even when there are no connectors present. 232 * Setup will be retried on the next hotplug event. 233 * 234 * The fbdev is destroyed by drm_dev_unregister(). 235 */ 236 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 237 { 238 struct drm_fb_helper *fb_helper; 239 int ret; 240 241 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 242 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 243 244 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 245 if (!fb_helper) 246 return; 247 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 248 249 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 250 if (ret) { 251 drm_err(dev, "Failed to register client: %d\n", ret); 252 goto err_drm_client_init; 253 } 254 255 drm_client_register(&fb_helper->client); 256 257 return; 258 259 err_drm_client_init: 260 drm_fb_helper_unprepare(fb_helper); 261 kfree(fb_helper); 262 } 263 EXPORT_SYMBOL(drm_fbdev_dma_setup); 264