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_vblank.h>
27
28#include "vkms_drv.h"
29
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
35
36static struct vkms_device *vkms_device;
37
38bool enable_cursor = true;
39module_param_named(enable_cursor, enable_cursor, bool, 0444);
40MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
41
42static const struct file_operations vkms_driver_fops = {
43	.owner		= THIS_MODULE,
44	.open		= drm_open,
45	.mmap		= drm_gem_mmap,
46	.unlocked_ioctl	= drm_ioctl,
47	.compat_ioctl	= drm_compat_ioctl,
48	.poll		= drm_poll,
49	.read		= drm_read,
50	.llseek		= no_llseek,
51	.release	= drm_release,
52};
53
54static 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,
58};
59
60static void vkms_release(struct drm_device *dev)
61{
62	struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
63
64	if (vkms->output.composer_workq)
65		destroy_workqueue(vkms->output.composer_workq);
66}
67
68static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
69{
70	struct drm_device *dev = old_state->dev;
71	struct drm_crtc *crtc;
72	struct drm_crtc_state *old_crtc_state;
73	int i;
74
75	drm_atomic_helper_commit_modeset_disables(dev, old_state);
76
77	drm_atomic_helper_commit_planes(dev, old_state, 0);
78
79	drm_atomic_helper_commit_modeset_enables(dev, old_state);
80
81	drm_atomic_helper_fake_vblank(old_state);
82
83	drm_atomic_helper_commit_hw_done(old_state);
84
85	drm_atomic_helper_wait_for_flip_done(dev, old_state);
86
87	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
88		struct vkms_crtc_state *vkms_state =
89			to_vkms_crtc_state(old_crtc_state);
90
91		flush_work(&vkms_state->composer_work);
92	}
93
94	drm_atomic_helper_cleanup_planes(dev, old_state);
95}
96
97static struct drm_driver vkms_driver = {
98	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
99	.release		= vkms_release,
100	.fops			= &vkms_driver_fops,
101	.dumb_create		= vkms_dumb_create,
102	.gem_vm_ops		= &vkms_gem_vm_ops,
103	.gem_free_object_unlocked = vkms_gem_free_object,
104	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
105	.gem_prime_import_sg_table = vkms_prime_import_sg_table,
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.cursor_width = 512;
135	dev->mode_config.cursor_height = 512;
136	dev->mode_config.preferred_depth = 24;
137	dev->mode_config.helper_private = &vkms_mode_config_helpers;
138
139	return vkms_output_init(vkmsdev, 0);
140}
141
142static int __init vkms_init(void)
143{
144	int ret;
145	struct platform_device *pdev;
146
147	pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
148	if (IS_ERR(pdev))
149		return PTR_ERR(pdev);
150
151	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
152		ret = -ENOMEM;
153		goto out_unregister;
154	}
155
156	vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
157					 struct vkms_device, drm);
158	if (IS_ERR(vkms_device)) {
159		ret = PTR_ERR(vkms_device);
160		goto out_devres;
161	}
162	vkms_device->platform = pdev;
163
164	ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
165					   DMA_BIT_MASK(64));
166
167	if (ret) {
168		DRM_ERROR("Could not initialize DMA support\n");
169		goto out_devres;
170	}
171
172	vkms_device->drm.irq_enabled = true;
173
174	ret = drm_vblank_init(&vkms_device->drm, 1);
175	if (ret) {
176		DRM_ERROR("Failed to vblank\n");
177		goto out_devres;
178	}
179
180	ret = vkms_modeset_init(vkms_device);
181	if (ret)
182		goto out_devres;
183
184	ret = drm_dev_register(&vkms_device->drm, 0);
185	if (ret)
186		goto out_devres;
187
188	return 0;
189
190out_devres:
191	devres_release_group(&pdev->dev, NULL);
192out_unregister:
193	platform_device_unregister(pdev);
194	return ret;
195}
196
197static void __exit vkms_exit(void)
198{
199	struct platform_device *pdev;
200
201	if (!vkms_device) {
202		DRM_INFO("vkms_device is NULL.\n");
203		return;
204	}
205
206	pdev = vkms_device->platform;
207
208	drm_dev_unregister(&vkms_device->drm);
209	drm_atomic_helper_shutdown(&vkms_device->drm);
210	devres_release_group(&pdev->dev, NULL);
211	platform_device_unregister(pdev);
212}
213
214module_init(vkms_init);
215module_exit(vkms_exit);
216
217MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
218MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
219MODULE_DESCRIPTION(DRIVER_DESC);
220MODULE_LICENSE("GPL");
221