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_start = page_to_phys(virt_to_page(info->screen_buffer)); 140 info->fix.smem_len = info->screen_size; 141 142 return 0; 143 144 err_drm_client_buffer_vunmap: 145 fb_helper->fb = NULL; 146 fb_helper->buffer = NULL; 147 drm_client_buffer_vunmap(buffer); 148 err_drm_client_buffer_delete: 149 drm_client_framebuffer_delete(buffer); 150 return ret; 151 } 152 153 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 154 .fb_probe = drm_fbdev_dma_helper_fb_probe, 155 }; 156 157 /* 158 * struct drm_client_funcs 159 */ 160 161 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 162 { 163 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 164 165 if (fb_helper->info) { 166 drm_fb_helper_unregister_info(fb_helper); 167 } else { 168 drm_client_release(&fb_helper->client); 169 drm_fb_helper_unprepare(fb_helper); 170 kfree(fb_helper); 171 } 172 } 173 174 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 175 { 176 drm_fb_helper_lastclose(client->dev); 177 178 return 0; 179 } 180 181 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 182 { 183 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 184 struct drm_device *dev = client->dev; 185 int ret; 186 187 if (dev->fb_helper) 188 return drm_fb_helper_hotplug_event(dev->fb_helper); 189 190 ret = drm_fb_helper_init(dev, fb_helper); 191 if (ret) 192 goto err_drm_err; 193 194 if (!drm_drv_uses_atomic_modeset(dev)) 195 drm_helper_disable_unused_functions(dev); 196 197 ret = drm_fb_helper_initial_config(fb_helper); 198 if (ret) 199 goto err_drm_fb_helper_fini; 200 201 return 0; 202 203 err_drm_fb_helper_fini: 204 drm_fb_helper_fini(fb_helper); 205 err_drm_err: 206 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 207 return ret; 208 } 209 210 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 211 .owner = THIS_MODULE, 212 .unregister = drm_fbdev_dma_client_unregister, 213 .restore = drm_fbdev_dma_client_restore, 214 .hotplug = drm_fbdev_dma_client_hotplug, 215 }; 216 217 /** 218 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 219 * @dev: DRM device 220 * @preferred_bpp: Preferred bits per pixel for the device. 221 * @dev->mode_config.preferred_depth is used if this is zero. 222 * 223 * This function sets up fbdev emulation for GEM DMA drivers that support 224 * dumb buffers with a virtual address and that can be mmap'ed. 225 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 226 * the new DRM device with drm_dev_register(). 227 * 228 * Restore, hotplug events and teardown are all taken care of. Drivers that do 229 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 230 * Simple drivers might use drm_mode_config_helper_suspend(). 231 * 232 * This function is safe to call even when there are no connectors present. 233 * Setup will be retried on the next hotplug event. 234 * 235 * The fbdev is destroyed by drm_dev_unregister(). 236 */ 237 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 238 { 239 struct drm_fb_helper *fb_helper; 240 int ret; 241 242 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 243 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 244 245 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 246 if (!fb_helper) 247 return; 248 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 249 250 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 251 if (ret) { 252 drm_err(dev, "Failed to register client: %d\n", ret); 253 goto err_drm_client_init; 254 } 255 256 ret = drm_fbdev_dma_client_hotplug(&fb_helper->client); 257 if (ret) 258 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret); 259 260 drm_client_register(&fb_helper->client); 261 262 return; 263 264 err_drm_client_init: 265 drm_fb_helper_unprepare(fb_helper); 266 kfree(fb_helper); 267 } 268 EXPORT_SYMBOL(drm_fbdev_dma_setup); 269