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_device *vkms_device; 38 39 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 DEFINE_DRM_GEM_FOPS(vkms_driver_fops); 44 45 static void vkms_release(struct drm_device *dev) 46 { 47 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm); 48 49 destroy_workqueue(vkms->output.composer_workq); 50 } 51 52 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 53 { 54 struct drm_device *dev = old_state->dev; 55 struct drm_crtc *crtc; 56 struct drm_crtc_state *old_crtc_state; 57 int i; 58 59 drm_atomic_helper_commit_modeset_disables(dev, old_state); 60 61 drm_atomic_helper_commit_planes(dev, old_state, 0); 62 63 drm_atomic_helper_commit_modeset_enables(dev, old_state); 64 65 drm_atomic_helper_fake_vblank(old_state); 66 67 drm_atomic_helper_commit_hw_done(old_state); 68 69 drm_atomic_helper_wait_for_flip_done(dev, old_state); 70 71 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 72 struct vkms_crtc_state *vkms_state = 73 to_vkms_crtc_state(old_crtc_state); 74 75 flush_work(&vkms_state->composer_work); 76 } 77 78 drm_atomic_helper_cleanup_planes(dev, old_state); 79 } 80 81 static const struct drm_driver vkms_driver = { 82 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 83 .release = vkms_release, 84 .fops = &vkms_driver_fops, 85 DRM_GEM_SHMEM_DRIVER_OPS, 86 87 .name = DRIVER_NAME, 88 .desc = DRIVER_DESC, 89 .date = DRIVER_DATE, 90 .major = DRIVER_MAJOR, 91 .minor = DRIVER_MINOR, 92 }; 93 94 static const struct drm_mode_config_funcs vkms_mode_funcs = { 95 .fb_create = drm_gem_fb_create, 96 .atomic_check = drm_atomic_helper_check, 97 .atomic_commit = drm_atomic_helper_commit, 98 }; 99 100 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 101 .atomic_commit_tail = vkms_atomic_commit_tail, 102 }; 103 104 static int vkms_modeset_init(struct vkms_device *vkmsdev) 105 { 106 struct drm_device *dev = &vkmsdev->drm; 107 108 drm_mode_config_init(dev); 109 dev->mode_config.funcs = &vkms_mode_funcs; 110 dev->mode_config.min_width = XRES_MIN; 111 dev->mode_config.min_height = YRES_MIN; 112 dev->mode_config.max_width = XRES_MAX; 113 dev->mode_config.max_height = YRES_MAX; 114 dev->mode_config.cursor_width = 512; 115 dev->mode_config.cursor_height = 512; 116 dev->mode_config.preferred_depth = 32; 117 dev->mode_config.helper_private = &vkms_mode_config_helpers; 118 119 return vkms_output_init(vkmsdev, 0); 120 } 121 122 static int __init vkms_init(void) 123 { 124 int ret; 125 struct platform_device *pdev; 126 127 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 128 if (IS_ERR(pdev)) 129 return PTR_ERR(pdev); 130 131 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) { 132 ret = -ENOMEM; 133 goto out_unregister; 134 } 135 136 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, 137 struct vkms_device, drm); 138 if (IS_ERR(vkms_device)) { 139 ret = PTR_ERR(vkms_device); 140 goto out_devres; 141 } 142 vkms_device->platform = pdev; 143 144 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev, 145 DMA_BIT_MASK(64)); 146 147 if (ret) { 148 DRM_ERROR("Could not initialize DMA support\n"); 149 goto out_devres; 150 } 151 152 vkms_device->drm.irq_enabled = true; 153 154 ret = drm_vblank_init(&vkms_device->drm, 1); 155 if (ret) { 156 DRM_ERROR("Failed to vblank\n"); 157 goto out_devres; 158 } 159 160 ret = vkms_modeset_init(vkms_device); 161 if (ret) 162 goto out_devres; 163 164 ret = drm_dev_register(&vkms_device->drm, 0); 165 if (ret) 166 goto out_devres; 167 168 drm_fbdev_generic_setup(&vkms_device->drm, 0); 169 170 return 0; 171 172 out_devres: 173 devres_release_group(&pdev->dev, NULL); 174 out_unregister: 175 platform_device_unregister(pdev); 176 return ret; 177 } 178 179 static void __exit vkms_exit(void) 180 { 181 struct platform_device *pdev; 182 183 if (!vkms_device) { 184 DRM_INFO("vkms_device is NULL.\n"); 185 return; 186 } 187 188 pdev = vkms_device->platform; 189 190 drm_dev_unregister(&vkms_device->drm); 191 drm_atomic_helper_shutdown(&vkms_device->drm); 192 devres_release_group(&pdev->dev, NULL); 193 platform_device_unregister(pdev); 194 } 195 196 module_init(vkms_init); 197 module_exit(vkms_exit); 198 199 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 200 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 201 MODULE_DESCRIPTION(DRIVER_DESC); 202 MODULE_LICENSE("GPL"); 203