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_drv.h> 20 #include <drm/drm_fb_helper.h> 21 #include <drm/drm_file.h> 22 #include <drm/drm_gem_framebuffer_helper.h> 23 #include <drm/drm_ioctl.h> 24 #include <drm/drm_managed.h> 25 #include <drm/drm_probe_helper.h> 26 #include <drm/drm_gem_shmem_helper.h> 27 #include <drm/drm_vblank.h> 28 29 #include "vkms_drv.h" 30 31 #include <drm/drm_print.h> 32 #include <drm/drm_debugfs.h> 33 34 #define DRIVER_NAME "vkms" 35 #define DRIVER_DESC "Virtual Kernel Mode Setting" 36 #define DRIVER_DATE "20180514" 37 #define DRIVER_MAJOR 1 38 #define DRIVER_MINOR 0 39 40 static struct vkms_config *default_config; 41 42 static bool enable_cursor = true; 43 module_param_named(enable_cursor, enable_cursor, bool, 0444); 44 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 45 46 static bool enable_writeback = true; 47 module_param_named(enable_writeback, enable_writeback, bool, 0444); 48 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support"); 49 50 static bool enable_overlay; 51 module_param_named(enable_overlay, enable_overlay, bool, 0444); 52 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support"); 53 54 DEFINE_DRM_GEM_FOPS(vkms_driver_fops); 55 56 static void vkms_release(struct drm_device *dev) 57 { 58 struct vkms_device *vkms = drm_device_to_vkms_device(dev); 59 60 destroy_workqueue(vkms->output.composer_workq); 61 } 62 63 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 64 { 65 struct drm_device *dev = old_state->dev; 66 struct drm_crtc *crtc; 67 struct drm_crtc_state *old_crtc_state; 68 int i; 69 70 drm_atomic_helper_commit_modeset_disables(dev, old_state); 71 72 drm_atomic_helper_commit_planes(dev, old_state, 0); 73 74 drm_atomic_helper_commit_modeset_enables(dev, old_state); 75 76 drm_atomic_helper_fake_vblank(old_state); 77 78 drm_atomic_helper_commit_hw_done(old_state); 79 80 drm_atomic_helper_wait_for_flip_done(dev, old_state); 81 82 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 83 struct vkms_crtc_state *vkms_state = 84 to_vkms_crtc_state(old_crtc_state); 85 86 flush_work(&vkms_state->composer_work); 87 } 88 89 drm_atomic_helper_cleanup_planes(dev, old_state); 90 } 91 92 static int vkms_config_show(struct seq_file *m, void *data) 93 { 94 struct drm_info_node *node = (struct drm_info_node *)m->private; 95 struct drm_device *dev = node->minor->dev; 96 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev); 97 98 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback); 99 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor); 100 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay); 101 102 return 0; 103 } 104 105 static const struct drm_info_list vkms_config_debugfs_list[] = { 106 { "vkms_config", vkms_config_show, 0 }, 107 }; 108 109 static void vkms_config_debugfs_init(struct drm_minor *minor) 110 { 111 drm_debugfs_create_files(vkms_config_debugfs_list, ARRAY_SIZE(vkms_config_debugfs_list), 112 minor->debugfs_root, minor); 113 } 114 115 static const struct drm_driver vkms_driver = { 116 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 117 .release = vkms_release, 118 .fops = &vkms_driver_fops, 119 DRM_GEM_SHMEM_DRIVER_OPS, 120 121 .debugfs_init = vkms_config_debugfs_init, 122 123 .name = DRIVER_NAME, 124 .desc = DRIVER_DESC, 125 .date = DRIVER_DATE, 126 .major = DRIVER_MAJOR, 127 .minor = DRIVER_MINOR, 128 }; 129 130 static const struct drm_mode_config_funcs vkms_mode_funcs = { 131 .fb_create = drm_gem_fb_create, 132 .atomic_check = drm_atomic_helper_check, 133 .atomic_commit = drm_atomic_helper_commit, 134 }; 135 136 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 137 .atomic_commit_tail = vkms_atomic_commit_tail, 138 }; 139 140 static int vkms_modeset_init(struct vkms_device *vkmsdev) 141 { 142 struct drm_device *dev = &vkmsdev->drm; 143 144 drm_mode_config_init(dev); 145 dev->mode_config.funcs = &vkms_mode_funcs; 146 dev->mode_config.min_width = XRES_MIN; 147 dev->mode_config.min_height = YRES_MIN; 148 dev->mode_config.max_width = XRES_MAX; 149 dev->mode_config.max_height = YRES_MAX; 150 dev->mode_config.cursor_width = 512; 151 dev->mode_config.cursor_height = 512; 152 /* FIXME: There's a confusion between bpp and depth between this and 153 * fbdev helpers. We have to go with 0, meaning "pick the default", 154 * which ix XRGB8888 in all cases. */ 155 dev->mode_config.preferred_depth = 0; 156 dev->mode_config.helper_private = &vkms_mode_config_helpers; 157 158 return vkms_output_init(vkmsdev, 0); 159 } 160 161 static int vkms_create(struct vkms_config *config) 162 { 163 int ret; 164 struct platform_device *pdev; 165 struct vkms_device *vkms_device; 166 167 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 168 if (IS_ERR(pdev)) 169 return PTR_ERR(pdev); 170 171 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) { 172 ret = -ENOMEM; 173 goto out_unregister; 174 } 175 176 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, 177 struct vkms_device, drm); 178 if (IS_ERR(vkms_device)) { 179 ret = PTR_ERR(vkms_device); 180 goto out_devres; 181 } 182 vkms_device->platform = pdev; 183 vkms_device->config = config; 184 config->dev = vkms_device; 185 186 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev, 187 DMA_BIT_MASK(64)); 188 189 if (ret) { 190 DRM_ERROR("Could not initialize DMA support\n"); 191 goto out_devres; 192 } 193 194 ret = drm_vblank_init(&vkms_device->drm, 1); 195 if (ret) { 196 DRM_ERROR("Failed to vblank\n"); 197 goto out_devres; 198 } 199 200 ret = vkms_modeset_init(vkms_device); 201 if (ret) 202 goto out_devres; 203 204 ret = drm_dev_register(&vkms_device->drm, 0); 205 if (ret) 206 goto out_devres; 207 208 drm_fbdev_generic_setup(&vkms_device->drm, 0); 209 210 return 0; 211 212 out_devres: 213 devres_release_group(&pdev->dev, NULL); 214 out_unregister: 215 platform_device_unregister(pdev); 216 return ret; 217 } 218 219 static int __init vkms_init(void) 220 { 221 struct vkms_config *config; 222 223 config = kmalloc(sizeof(*config), GFP_KERNEL); 224 if (!config) 225 return -ENOMEM; 226 227 default_config = config; 228 229 config->cursor = enable_cursor; 230 config->writeback = enable_writeback; 231 config->overlay = enable_overlay; 232 233 return vkms_create(config); 234 } 235 236 static void vkms_destroy(struct vkms_config *config) 237 { 238 struct platform_device *pdev; 239 240 if (!config->dev) { 241 DRM_INFO("vkms_device is NULL.\n"); 242 return; 243 } 244 245 pdev = config->dev->platform; 246 247 drm_dev_unregister(&config->dev->drm); 248 drm_atomic_helper_shutdown(&config->dev->drm); 249 devres_release_group(&pdev->dev, NULL); 250 platform_device_unregister(pdev); 251 252 config->dev = NULL; 253 } 254 255 static void __exit vkms_exit(void) 256 { 257 if (default_config->dev) 258 vkms_destroy(default_config); 259 260 kfree(default_config); 261 } 262 263 module_init(vkms_init); 264 module_exit(vkms_exit); 265 266 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 267 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 268 MODULE_DESCRIPTION(DRIVER_DESC); 269 MODULE_LICENSE("GPL"); 270