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_fbdev_shmem.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 if (vkms->output.composer_workq) 61 destroy_workqueue(vkms->output.composer_workq); 62 } 63 64 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 65 { 66 struct drm_device *dev = old_state->dev; 67 struct drm_crtc *crtc; 68 struct drm_crtc_state *old_crtc_state; 69 int i; 70 71 drm_atomic_helper_commit_modeset_disables(dev, old_state); 72 73 drm_atomic_helper_commit_planes(dev, old_state, 0); 74 75 drm_atomic_helper_commit_modeset_enables(dev, old_state); 76 77 drm_atomic_helper_fake_vblank(old_state); 78 79 drm_atomic_helper_commit_hw_done(old_state); 80 81 drm_atomic_helper_wait_for_flip_done(dev, old_state); 82 83 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 84 struct vkms_crtc_state *vkms_state = 85 to_vkms_crtc_state(old_crtc_state); 86 87 flush_work(&vkms_state->composer_work); 88 } 89 90 drm_atomic_helper_cleanup_planes(dev, old_state); 91 } 92 93 static int vkms_config_show(struct seq_file *m, void *data) 94 { 95 struct drm_debugfs_entry *entry = m->private; 96 struct drm_device *dev = entry->dev; 97 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev); 98 99 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback); 100 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor); 101 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay); 102 103 return 0; 104 } 105 106 static const struct drm_debugfs_info vkms_config_debugfs_list[] = { 107 { "vkms_config", vkms_config_show, 0 }, 108 }; 109 110 static const struct drm_driver vkms_driver = { 111 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 112 .release = vkms_release, 113 .fops = &vkms_driver_fops, 114 DRM_GEM_SHMEM_DRIVER_OPS, 115 116 .name = DRIVER_NAME, 117 .desc = DRIVER_DESC, 118 .date = DRIVER_DATE, 119 .major = DRIVER_MAJOR, 120 .minor = DRIVER_MINOR, 121 }; 122 123 static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state) 124 { 125 struct drm_crtc *crtc; 126 struct drm_crtc_state *new_crtc_state; 127 int i; 128 129 for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { 130 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed) 131 continue; 132 133 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *) 134 > VKMS_LUT_SIZE) 135 return -EINVAL; 136 } 137 138 return drm_atomic_helper_check(dev, state); 139 } 140 141 static const struct drm_mode_config_funcs vkms_mode_funcs = { 142 .fb_create = drm_gem_fb_create, 143 .atomic_check = vkms_atomic_check, 144 .atomic_commit = drm_atomic_helper_commit, 145 }; 146 147 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 148 .atomic_commit_tail = vkms_atomic_commit_tail, 149 }; 150 151 static int vkms_modeset_init(struct vkms_device *vkmsdev) 152 { 153 struct drm_device *dev = &vkmsdev->drm; 154 int ret; 155 156 ret = drmm_mode_config_init(dev); 157 if (ret) 158 return ret; 159 160 dev->mode_config.funcs = &vkms_mode_funcs; 161 dev->mode_config.min_width = XRES_MIN; 162 dev->mode_config.min_height = YRES_MIN; 163 dev->mode_config.max_width = XRES_MAX; 164 dev->mode_config.max_height = YRES_MAX; 165 dev->mode_config.cursor_width = 512; 166 dev->mode_config.cursor_height = 512; 167 /* FIXME: There's a confusion between bpp and depth between this and 168 * fbdev helpers. We have to go with 0, meaning "pick the default", 169 * which ix XRGB8888 in all cases. */ 170 dev->mode_config.preferred_depth = 0; 171 dev->mode_config.helper_private = &vkms_mode_config_helpers; 172 173 return vkms_output_init(vkmsdev, 0); 174 } 175 176 static int vkms_create(struct vkms_config *config) 177 { 178 int ret; 179 struct platform_device *pdev; 180 struct vkms_device *vkms_device; 181 182 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 183 if (IS_ERR(pdev)) 184 return PTR_ERR(pdev); 185 186 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) { 187 ret = -ENOMEM; 188 goto out_unregister; 189 } 190 191 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, 192 struct vkms_device, drm); 193 if (IS_ERR(vkms_device)) { 194 ret = PTR_ERR(vkms_device); 195 goto out_devres; 196 } 197 vkms_device->platform = pdev; 198 vkms_device->config = config; 199 config->dev = vkms_device; 200 201 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev, 202 DMA_BIT_MASK(64)); 203 204 if (ret) { 205 DRM_ERROR("Could not initialize DMA support\n"); 206 goto out_devres; 207 } 208 209 ret = drm_vblank_init(&vkms_device->drm, 1); 210 if (ret) { 211 DRM_ERROR("Failed to vblank\n"); 212 goto out_devres; 213 } 214 215 ret = vkms_modeset_init(vkms_device); 216 if (ret) 217 goto out_devres; 218 219 drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list, 220 ARRAY_SIZE(vkms_config_debugfs_list)); 221 222 ret = drm_dev_register(&vkms_device->drm, 0); 223 if (ret) 224 goto out_devres; 225 226 drm_fbdev_shmem_setup(&vkms_device->drm, 0); 227 228 return 0; 229 230 out_devres: 231 devres_release_group(&pdev->dev, NULL); 232 out_unregister: 233 platform_device_unregister(pdev); 234 return ret; 235 } 236 237 static int __init vkms_init(void) 238 { 239 int ret; 240 struct vkms_config *config; 241 242 config = kmalloc(sizeof(*config), GFP_KERNEL); 243 if (!config) 244 return -ENOMEM; 245 246 default_config = config; 247 248 config->cursor = enable_cursor; 249 config->writeback = enable_writeback; 250 config->overlay = enable_overlay; 251 252 ret = vkms_create(config); 253 if (ret) 254 kfree(config); 255 256 return ret; 257 } 258 259 static void vkms_destroy(struct vkms_config *config) 260 { 261 struct platform_device *pdev; 262 263 if (!config->dev) { 264 DRM_INFO("vkms_device is NULL.\n"); 265 return; 266 } 267 268 pdev = config->dev->platform; 269 270 drm_dev_unregister(&config->dev->drm); 271 drm_atomic_helper_shutdown(&config->dev->drm); 272 devres_release_group(&pdev->dev, NULL); 273 platform_device_unregister(pdev); 274 275 config->dev = NULL; 276 } 277 278 static void __exit vkms_exit(void) 279 { 280 if (default_config->dev) 281 vkms_destroy(default_config); 282 283 kfree(default_config); 284 } 285 286 module_init(vkms_init); 287 module_exit(vkms_exit); 288 289 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 290 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 291 MODULE_DESCRIPTION(DRIVER_DESC); 292 MODULE_LICENSE("GPL"); 293