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	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);
 68}
 69
 70static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
 71{
 72	struct drm_device *dev = old_state->dev;
 73	struct drm_crtc *crtc;
 74	struct drm_crtc_state *old_crtc_state;
 75	int i;
 76
 77	drm_atomic_helper_commit_modeset_disables(dev, old_state);
 78
 79	drm_atomic_helper_commit_planes(dev, old_state, 0);
 80
 81	drm_atomic_helper_commit_modeset_enables(dev, old_state);
 82
 83	drm_atomic_helper_fake_vblank(old_state);
 84
 85	drm_atomic_helper_commit_hw_done(old_state);
 86
 87	drm_atomic_helper_wait_for_flip_done(dev, old_state);
 88
 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);
 92
 93		flush_work(&vkms_state->composer_work);
 94	}
 95
 96	drm_atomic_helper_cleanup_planes(dev, old_state);
 97}
 98
 99static 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,
108
109	.name			= DRIVER_NAME,
110	.desc			= DRIVER_DESC,
111	.date			= DRIVER_DATE,
112	.major			= DRIVER_MAJOR,
113	.minor			= DRIVER_MINOR,
114};
115
116static 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,
120};
121
122static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
123	.atomic_commit_tail = vkms_atomic_commit_tail,
124};
125
126static int vkms_modeset_init(struct vkms_device *vkmsdev)
127{
128	struct drm_device *dev = &vkmsdev->drm;
129
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;
140
141	return vkms_output_init(vkmsdev, 0);
142}
143
144static int __init vkms_init(void)
145{
146	int ret;
147
148	vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
149	if (!vkms_device)
150		return -ENOMEM;
151
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);
156		goto out_free;
157	}
158
159	ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
160			   &vkms_device->platform->dev);
161	if (ret)
162		goto out_unregister;
163	drmm_add_final_kfree(&vkms_device->drm, vkms_device);
164
165	ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
166					   DMA_BIT_MASK(64));
167
168	if (ret) {
169		DRM_ERROR("Could not initialize DMA support\n");
170		goto out_put;
171	}
172
173	vkms_device->drm.irq_enabled = true;
174
175	ret = drm_vblank_init(&vkms_device->drm, 1);
176	if (ret) {
177		DRM_ERROR("Failed to vblank\n");
178		goto out_put;
179	}
180
181	ret = vkms_modeset_init(vkms_device);
182	if (ret)
183		goto out_put;
184
185	ret = drm_dev_register(&vkms_device->drm, 0);
186	if (ret)
187		goto out_put;
188
189	return 0;
190
191out_put:
192	drm_dev_put(&vkms_device->drm);
193	return ret;
194
195out_unregister:
196	platform_device_unregister(vkms_device->platform);
197out_free:
198	kfree(vkms_device);
199	return ret;
200}
201
202static void __exit vkms_exit(void)
203{
204	if (!vkms_device) {
205		DRM_INFO("vkms_device is NULL.\n");
206		return;
207	}
208
209	drm_dev_unregister(&vkms_device->drm);
210	drm_dev_put(&vkms_device->drm);
211}
212
213module_init(vkms_init);
214module_exit(vkms_exit);
215
216MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
217MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
218MODULE_DESCRIPTION(DRIVER_DESC);
219MODULE_LICENSE("GPL");