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 * or for running X (or similar) on headless machines and be able to still
  8 * use the GPU. vkms aims to enable a virtual display without the need for
  9 * a hardware display capability.
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/platform_device.h>
 14
 15#include <drm/drm_atomic.h>
 16#include <drm/drm_atomic_helper.h>
 17#include <drm/drm_drv.h>
 18#include <drm/drm_fb_helper.h>
 19#include <drm/drm_file.h>
 20#include <drm/drm_gem.h>
 21#include <drm/drm_gem_framebuffer_helper.h>
 22#include <drm/drm_ioctl.h>
 23#include <drm/drm_probe_helper.h>
 24#include <drm/drm_vblank.h>
 25
 26#include "vkms_drv.h"
 27
 28#define DRIVER_NAME	"vkms"
 29#define DRIVER_DESC	"Virtual Kernel Mode Setting"
 30#define DRIVER_DATE	"20180514"
 31#define DRIVER_MAJOR	1
 32#define DRIVER_MINOR	0
 33
 34static struct vkms_device *vkms_device;
 35
 36bool enable_cursor;
 37module_param_named(enable_cursor, enable_cursor, bool, 0444);
 38MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
 39
 40static const struct file_operations vkms_driver_fops = {
 41	.owner		= THIS_MODULE,
 42	.open		= drm_open,
 43	.mmap		= drm_gem_mmap,
 44	.unlocked_ioctl	= drm_ioctl,
 45	.compat_ioctl	= drm_compat_ioctl,
 46	.poll		= drm_poll,
 47	.read		= drm_read,
 48	.llseek		= no_llseek,
 49	.release	= drm_release,
 50};
 51
 52static const struct vm_operations_struct vkms_gem_vm_ops = {
 53	.fault = vkms_gem_fault,
 54	.open = drm_gem_vm_open,
 55	.close = drm_gem_vm_close,
 56};
 57
 58static void vkms_release(struct drm_device *dev)
 59{
 60	struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
 61
 62	platform_device_unregister(vkms->platform);
 63	drm_atomic_helper_shutdown(&vkms->drm);
 64	drm_mode_config_cleanup(&vkms->drm);
 65	drm_dev_fini(&vkms->drm);
 66	destroy_workqueue(vkms->output.composer_workq);
 67}
 68
 69static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
 70{
 71	struct drm_device *dev = old_state->dev;
 72	struct drm_crtc *crtc;
 73	struct drm_crtc_state *old_crtc_state;
 74	int i;
 75
 76	drm_atomic_helper_commit_modeset_disables(dev, old_state);
 77
 78	drm_atomic_helper_commit_planes(dev, old_state, 0);
 79
 80	drm_atomic_helper_commit_modeset_enables(dev, old_state);
 81
 82	drm_atomic_helper_fake_vblank(old_state);
 83
 84	drm_atomic_helper_commit_hw_done(old_state);
 85
 86	drm_atomic_helper_wait_for_vblanks(dev, old_state);
 87
 88	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
 89		struct vkms_crtc_state *vkms_state =
 90			to_vkms_crtc_state(old_crtc_state);
 91
 92		flush_work(&vkms_state->composer_work);
 93	}
 94
 95	drm_atomic_helper_cleanup_planes(dev, old_state);
 96}
 97
 98static struct drm_driver vkms_driver = {
 99	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
100	.release		= vkms_release,
101	.fops			= &vkms_driver_fops,
102	.dumb_create		= vkms_dumb_create,
103	.gem_vm_ops		= &vkms_gem_vm_ops,
104	.gem_free_object_unlocked = vkms_gem_free_object,
105	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
106
107	.name			= DRIVER_NAME,
108	.desc			= DRIVER_DESC,
109	.date			= DRIVER_DATE,
110	.major			= DRIVER_MAJOR,
111	.minor			= DRIVER_MINOR,
112};
113
114static const struct drm_mode_config_funcs vkms_mode_funcs = {
115	.fb_create = drm_gem_fb_create,
116	.atomic_check = drm_atomic_helper_check,
117	.atomic_commit = drm_atomic_helper_commit,
118};
119
120static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
121	.atomic_commit_tail = vkms_atomic_commit_tail,
122};
123
124static int vkms_modeset_init(struct vkms_device *vkmsdev)
125{
126	struct drm_device *dev = &vkmsdev->drm;
127
128	drm_mode_config_init(dev);
129	dev->mode_config.funcs = &vkms_mode_funcs;
130	dev->mode_config.min_width = XRES_MIN;
131	dev->mode_config.min_height = YRES_MIN;
132	dev->mode_config.max_width = XRES_MAX;
133	dev->mode_config.max_height = YRES_MAX;
134	dev->mode_config.preferred_depth = 24;
135	dev->mode_config.helper_private = &vkms_mode_config_helpers;
136
137	return vkms_output_init(vkmsdev, 0);
138}
139
140static int __init vkms_init(void)
141{
142	int ret;
143
144	vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
145	if (!vkms_device)
146		return -ENOMEM;
147
148	vkms_device->platform =
149		platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
150	if (IS_ERR(vkms_device->platform)) {
151		ret = PTR_ERR(vkms_device->platform);
152		goto out_free;
153	}
154
155	ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
156			   &vkms_device->platform->dev);
157	if (ret)
158		goto out_unregister;
159
160	vkms_device->drm.irq_enabled = true;
161
162	ret = drm_vblank_init(&vkms_device->drm, 1);
163	if (ret) {
164		DRM_ERROR("Failed to vblank\n");
165		goto out_fini;
166	}
167
168	ret = vkms_modeset_init(vkms_device);
169	if (ret)
170		goto out_fini;
171
172	ret = drm_dev_register(&vkms_device->drm, 0);
173	if (ret)
174		goto out_fini;
175
176	return 0;
177
178out_fini:
179	drm_dev_fini(&vkms_device->drm);
180
181out_unregister:
182	platform_device_unregister(vkms_device->platform);
183
184out_free:
185	kfree(vkms_device);
186	return ret;
187}
188
189static void __exit vkms_exit(void)
190{
191	if (!vkms_device) {
192		DRM_INFO("vkms_device is NULL.\n");
193		return;
194	}
195
196	drm_dev_unregister(&vkms_device->drm);
197	drm_dev_put(&vkms_device->drm);
198
199	kfree(vkms_device);
200}
201
202module_init(vkms_init);
203module_exit(vkms_exit);
204
205MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
206MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
207MODULE_DESCRIPTION(DRIVER_DESC);
208MODULE_LICENSE("GPL");