1 // SPDX-License-Identifier: GPL-2.0+ 2 3 /** 4 * DOC: vkms (Virtual Kernel Modesetting) 5 * 6 * VKMS is a software-only model of a KMS driver that is useful for testing 7 * and for running X (or similar) on headless machines. VKMS aims to enable 8 * a virtual display with no need of a hardware display capability, releasing 9 * the GPU in DRM API tests. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/dma-mapping.h> 15 16 #include <drm/drm_gem.h> 17 #include <drm/drm_atomic.h> 18 #include <drm/drm_atomic_helper.h> 19 #include <drm/drm_client_setup.h> 20 #include <drm/drm_drv.h> 21 #include <drm/drm_fbdev_shmem.h> 22 #include <drm/drm_file.h> 23 #include <drm/drm_gem_framebuffer_helper.h> 24 #include <drm/drm_ioctl.h> 25 #include <drm/drm_managed.h> 26 #include <drm/drm_probe_helper.h> 27 #include <drm/drm_gem_shmem_helper.h> 28 #include <drm/drm_vblank.h> 29 30 #include "vkms_drv.h" 31 32 #include <drm/drm_print.h> 33 #include <drm/drm_debugfs.h> 34 35 #define DRIVER_NAME "vkms" 36 #define DRIVER_DESC "Virtual Kernel Mode Setting" 37 #define DRIVER_DATE "20180514" 38 #define DRIVER_MAJOR 1 39 #define DRIVER_MINOR 0 40 41 static struct vkms_config *default_config; 42 43 static bool enable_cursor = true; 44 module_param_named(enable_cursor, enable_cursor, bool, 0444); 45 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 46 47 static bool enable_writeback = true; 48 module_param_named(enable_writeback, enable_writeback, bool, 0444); 49 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support"); 50 51 static bool enable_overlay; 52 module_param_named(enable_overlay, enable_overlay, bool, 0444); 53 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support"); 54 55 DEFINE_DRM_GEM_FOPS(vkms_driver_fops); 56 57 static void vkms_release(struct drm_device *dev) 58 { 59 struct vkms_device *vkms = drm_device_to_vkms_device(dev); 60 61 if (vkms->output.composer_workq) 62 destroy_workqueue(vkms->output.composer_workq); 63 } 64 65 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 66 { 67 struct drm_device *dev = old_state->dev; 68 struct drm_crtc *crtc; 69 struct drm_crtc_state *old_crtc_state; 70 int i; 71 72 drm_atomic_helper_commit_modeset_disables(dev, old_state); 73 74 drm_atomic_helper_commit_planes(dev, old_state, 0); 75 76 drm_atomic_helper_commit_modeset_enables(dev, old_state); 77 78 drm_atomic_helper_fake_vblank(old_state); 79 80 drm_atomic_helper_commit_hw_done(old_state); 81 82 drm_atomic_helper_wait_for_flip_done(dev, old_state); 83 84 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 85 struct vkms_crtc_state *vkms_state = 86 to_vkms_crtc_state(old_crtc_state); 87 88 flush_work(&vkms_state->composer_work); 89 } 90 91 drm_atomic_helper_cleanup_planes(dev, old_state); 92 } 93 94 static int vkms_config_show(struct seq_file *m, void *data) 95 { 96 struct drm_debugfs_entry *entry = m->private; 97 struct drm_device *dev = entry->dev; 98 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev); 99 100 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback); 101 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor); 102 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay); 103 104 return 0; 105 } 106 107 static const struct drm_debugfs_info vkms_config_debugfs_list[] = { 108 { "vkms_config", vkms_config_show, 0 }, 109 }; 110 111 static const struct drm_driver vkms_driver = { 112 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 113 .release = vkms_release, 114 .fops = &vkms_driver_fops, 115 DRM_GEM_SHMEM_DRIVER_OPS, 116 DRM_FBDEV_SHMEM_DRIVER_OPS, 117 118 .name = DRIVER_NAME, 119 .desc = DRIVER_DESC, 120 .date = DRIVER_DATE, 121 .major = DRIVER_MAJOR, 122 .minor = DRIVER_MINOR, 123 }; 124 125 static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state) 126 { 127 struct drm_crtc *crtc; 128 struct drm_crtc_state *new_crtc_state; 129 int i; 130 131 for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { 132 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed) 133 continue; 134 135 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *) 136 > VKMS_LUT_SIZE) 137 return -EINVAL; 138 } 139 140 return drm_atomic_helper_check(dev, state); 141 } 142 143 static const struct drm_mode_config_funcs vkms_mode_funcs = { 144 .fb_create = drm_gem_fb_create, 145 .atomic_check = vkms_atomic_check, 146 .atomic_commit = drm_atomic_helper_commit, 147 }; 148 149 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 150 .atomic_commit_tail = vkms_atomic_commit_tail, 151 }; 152 153 static int vkms_modeset_init(struct vkms_device *vkmsdev) 154 { 155 struct drm_device *dev = &vkmsdev->drm; 156 int ret; 157 158 ret = drmm_mode_config_init(dev); 159 if (ret) 160 return ret; 161 162 dev->mode_config.funcs = &vkms_mode_funcs; 163 dev->mode_config.min_width = XRES_MIN; 164 dev->mode_config.min_height = YRES_MIN; 165 dev->mode_config.max_width = XRES_MAX; 166 dev->mode_config.max_height = YRES_MAX; 167 dev->mode_config.cursor_width = 512; 168 dev->mode_config.cursor_height = 512; 169 /* 170 * FIXME: There's a confusion between bpp and depth between this and 171 * fbdev helpers. We have to go with 0, meaning "pick the default", 172 * which is XRGB8888 in all cases. 173 */ 174 dev->mode_config.preferred_depth = 0; 175 dev->mode_config.helper_private = &vkms_mode_config_helpers; 176 177 return vkms_output_init(vkmsdev, 0); 178 } 179 180 static int vkms_create(struct vkms_config *config) 181 { 182 int ret; 183 struct platform_device *pdev; 184 struct vkms_device *vkms_device; 185 186 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 187 if (IS_ERR(pdev)) 188 return PTR_ERR(pdev); 189 190 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) { 191 ret = -ENOMEM; 192 goto out_unregister; 193 } 194 195 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, 196 struct vkms_device, drm); 197 if (IS_ERR(vkms_device)) { 198 ret = PTR_ERR(vkms_device); 199 goto out_devres; 200 } 201 vkms_device->platform = pdev; 202 vkms_device->config = config; 203 config->dev = vkms_device; 204 205 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev, 206 DMA_BIT_MASK(64)); 207 208 if (ret) { 209 DRM_ERROR("Could not initialize DMA support\n"); 210 goto out_devres; 211 } 212 213 ret = drm_vblank_init(&vkms_device->drm, 1); 214 if (ret) { 215 DRM_ERROR("Failed to vblank\n"); 216 goto out_devres; 217 } 218 219 ret = vkms_modeset_init(vkms_device); 220 if (ret) 221 goto out_devres; 222 223 drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list, 224 ARRAY_SIZE(vkms_config_debugfs_list)); 225 226 ret = drm_dev_register(&vkms_device->drm, 0); 227 if (ret) 228 goto out_devres; 229 230 drm_client_setup(&vkms_device->drm, NULL); 231 232 return 0; 233 234 out_devres: 235 devres_release_group(&pdev->dev, NULL); 236 out_unregister: 237 platform_device_unregister(pdev); 238 return ret; 239 } 240 241 static int __init vkms_init(void) 242 { 243 int ret; 244 struct vkms_config *config; 245 246 config = kmalloc(sizeof(*config), GFP_KERNEL); 247 if (!config) 248 return -ENOMEM; 249 250 default_config = config; 251 252 config->cursor = enable_cursor; 253 config->writeback = enable_writeback; 254 config->overlay = enable_overlay; 255 256 ret = vkms_create(config); 257 if (ret) 258 kfree(config); 259 260 return ret; 261 } 262 263 static void vkms_destroy(struct vkms_config *config) 264 { 265 struct platform_device *pdev; 266 267 if (!config->dev) { 268 DRM_INFO("vkms_device is NULL.\n"); 269 return; 270 } 271 272 pdev = config->dev->platform; 273 274 drm_dev_unregister(&config->dev->drm); 275 drm_atomic_helper_shutdown(&config->dev->drm); 276 devres_release_group(&pdev->dev, NULL); 277 platform_device_unregister(pdev); 278 279 config->dev = NULL; 280 } 281 282 static void __exit vkms_exit(void) 283 { 284 if (default_config->dev) 285 vkms_destroy(default_config); 286 287 kfree(default_config); 288 } 289 290 module_init(vkms_init); 291 module_exit(vkms_exit); 292 293 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 294 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 295 MODULE_DESCRIPTION(DRIVER_DESC); 296 MODULE_LICENSE("GPL"); 297