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