1 // SPDX-License-Identifier: GPL-2.0+
4 * DOC: vkms (Virtual Kernel Modesetting)
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.
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/dma-mapping.h>
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_vblank.h>
30 #define DRIVER_NAME "vkms"
31 #define DRIVER_DESC "Virtual Kernel Mode Setting"
32 #define DRIVER_DATE "20180514"
33 #define DRIVER_MAJOR 1
34 #define DRIVER_MINOR 0
36 static struct vkms_device *vkms_device;
38 bool enable_cursor = true;
39 module_param_named(enable_cursor, enable_cursor, bool, 0444);
40 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
42 static const struct file_operations vkms_driver_fops = {
46 .unlocked_ioctl = drm_ioctl,
47 .compat_ioctl = drm_compat_ioctl,
51 .release = drm_release,
54 static const struct vm_operations_struct vkms_gem_vm_ops = {
55 .fault = vkms_gem_fault,
56 .open = drm_gem_vm_open,
57 .close = drm_gem_vm_close,
60 static void vkms_release(struct drm_device *dev)
62 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
64 platform_device_unregister(vkms->platform);
65 drm_atomic_helper_shutdown(&vkms->drm);
66 drm_mode_config_cleanup(&vkms->drm);
67 destroy_workqueue(vkms->output.composer_workq);
70 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
72 struct drm_device *dev = old_state->dev;
73 struct drm_crtc *crtc;
74 struct drm_crtc_state *old_crtc_state;
77 drm_atomic_helper_commit_modeset_disables(dev, old_state);
79 drm_atomic_helper_commit_planes(dev, old_state, 0);
81 drm_atomic_helper_commit_modeset_enables(dev, old_state);
83 drm_atomic_helper_fake_vblank(old_state);
85 drm_atomic_helper_commit_hw_done(old_state);
87 drm_atomic_helper_wait_for_flip_done(dev, old_state);
89 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
90 struct vkms_crtc_state *vkms_state =
91 to_vkms_crtc_state(old_crtc_state);
93 flush_work(&vkms_state->composer_work);
96 drm_atomic_helper_cleanup_planes(dev, old_state);
99 static struct drm_driver vkms_driver = {
100 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
101 .release = vkms_release,
102 .fops = &vkms_driver_fops,
103 .dumb_create = vkms_dumb_create,
104 .gem_vm_ops = &vkms_gem_vm_ops,
105 .gem_free_object_unlocked = vkms_gem_free_object,
106 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
107 .gem_prime_import_sg_table = vkms_prime_import_sg_table,
112 .major = DRIVER_MAJOR,
113 .minor = DRIVER_MINOR,
116 static const struct drm_mode_config_funcs vkms_mode_funcs = {
117 .fb_create = drm_gem_fb_create,
118 .atomic_check = drm_atomic_helper_check,
119 .atomic_commit = drm_atomic_helper_commit,
122 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
123 .atomic_commit_tail = vkms_atomic_commit_tail,
126 static int vkms_modeset_init(struct vkms_device *vkmsdev)
128 struct drm_device *dev = &vkmsdev->drm;
130 drm_mode_config_init(dev);
131 dev->mode_config.funcs = &vkms_mode_funcs;
132 dev->mode_config.min_width = XRES_MIN;
133 dev->mode_config.min_height = YRES_MIN;
134 dev->mode_config.max_width = XRES_MAX;
135 dev->mode_config.max_height = YRES_MAX;
136 dev->mode_config.cursor_width = 512;
137 dev->mode_config.cursor_height = 512;
138 dev->mode_config.preferred_depth = 24;
139 dev->mode_config.helper_private = &vkms_mode_config_helpers;
141 return vkms_output_init(vkmsdev, 0);
144 static int __init vkms_init(void)
148 vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
152 vkms_device->platform =
153 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
154 if (IS_ERR(vkms_device->platform)) {
155 ret = PTR_ERR(vkms_device->platform);
159 ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
160 &vkms_device->platform->dev);
163 drmm_add_final_kfree(&vkms_device->drm, vkms_device);
165 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
169 DRM_ERROR("Could not initialize DMA support\n");
173 vkms_device->drm.irq_enabled = true;
175 ret = drm_vblank_init(&vkms_device->drm, 1);
177 DRM_ERROR("Failed to vblank\n");
181 ret = vkms_modeset_init(vkms_device);
185 ret = drm_dev_register(&vkms_device->drm, 0);
192 drm_dev_put(&vkms_device->drm);
193 platform_device_unregister(vkms_device->platform);
196 platform_device_unregister(vkms_device->platform);
202 static void __exit vkms_exit(void)
205 DRM_INFO("vkms_device is NULL.\n");
209 drm_dev_unregister(&vkms_device->drm);
210 drm_dev_put(&vkms_device->drm);
213 module_init(vkms_init);
214 module_exit(vkms_exit);
218 MODULE_DESCRIPTION(DRIVER_DESC);
219 MODULE_LICENSE("GPL");