xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_drv.c (revision 5b628549)
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 <drm/drm_gem.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_gem_framebuffer_helper.h>
16 #include <drm/drm_fb_helper.h>
17 #include <drm/drm_probe_helper.h>
18 #include "vkms_drv.h"
19 
20 #define DRIVER_NAME	"vkms"
21 #define DRIVER_DESC	"Virtual Kernel Mode Setting"
22 #define DRIVER_DATE	"20180514"
23 #define DRIVER_MAJOR	1
24 #define DRIVER_MINOR	0
25 
26 static struct vkms_device *vkms_device;
27 
28 bool enable_cursor;
29 module_param_named(enable_cursor, enable_cursor, bool, 0444);
30 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
31 
32 static const struct file_operations vkms_driver_fops = {
33 	.owner		= THIS_MODULE,
34 	.open		= drm_open,
35 	.mmap		= drm_gem_mmap,
36 	.unlocked_ioctl	= drm_ioctl,
37 	.compat_ioctl	= drm_compat_ioctl,
38 	.poll		= drm_poll,
39 	.read		= drm_read,
40 	.llseek		= no_llseek,
41 	.release	= drm_release,
42 };
43 
44 static const struct vm_operations_struct vkms_gem_vm_ops = {
45 	.fault = vkms_gem_fault,
46 	.open = drm_gem_vm_open,
47 	.close = drm_gem_vm_close,
48 };
49 
50 static void vkms_release(struct drm_device *dev)
51 {
52 	struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
53 
54 	platform_device_unregister(vkms->platform);
55 	drm_atomic_helper_shutdown(&vkms->drm);
56 	drm_mode_config_cleanup(&vkms->drm);
57 	drm_dev_fini(&vkms->drm);
58 	destroy_workqueue(vkms->output.crc_workq);
59 }
60 
61 static struct drm_driver vkms_driver = {
62 	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
63 	.release		= vkms_release,
64 	.fops			= &vkms_driver_fops,
65 	.dumb_create		= vkms_dumb_create,
66 	.gem_vm_ops		= &vkms_gem_vm_ops,
67 	.gem_free_object_unlocked = vkms_gem_free_object,
68 	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
69 
70 	.name			= DRIVER_NAME,
71 	.desc			= DRIVER_DESC,
72 	.date			= DRIVER_DATE,
73 	.major			= DRIVER_MAJOR,
74 	.minor			= DRIVER_MINOR,
75 };
76 
77 static const struct drm_mode_config_funcs vkms_mode_funcs = {
78 	.fb_create = drm_gem_fb_create,
79 	.atomic_check = drm_atomic_helper_check,
80 	.atomic_commit = drm_atomic_helper_commit,
81 };
82 
83 static int vkms_modeset_init(struct vkms_device *vkmsdev)
84 {
85 	struct drm_device *dev = &vkmsdev->drm;
86 
87 	drm_mode_config_init(dev);
88 	dev->mode_config.funcs = &vkms_mode_funcs;
89 	dev->mode_config.min_width = XRES_MIN;
90 	dev->mode_config.min_height = YRES_MIN;
91 	dev->mode_config.max_width = XRES_MAX;
92 	dev->mode_config.max_height = YRES_MAX;
93 	dev->mode_config.preferred_depth = 24;
94 
95 	return vkms_output_init(vkmsdev);
96 }
97 
98 static int __init vkms_init(void)
99 {
100 	int ret;
101 
102 	vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
103 	if (!vkms_device)
104 		return -ENOMEM;
105 
106 	vkms_device->platform =
107 		platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
108 	if (IS_ERR(vkms_device->platform)) {
109 		ret = PTR_ERR(vkms_device->platform);
110 		goto out_free;
111 	}
112 
113 	ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
114 			   &vkms_device->platform->dev);
115 	if (ret)
116 		goto out_unregister;
117 
118 	vkms_device->drm.irq_enabled = true;
119 
120 	ret = drm_vblank_init(&vkms_device->drm, 1);
121 	if (ret) {
122 		DRM_ERROR("Failed to vblank\n");
123 		goto out_fini;
124 	}
125 
126 	ret = vkms_modeset_init(vkms_device);
127 	if (ret)
128 		goto out_fini;
129 
130 	ret = drm_dev_register(&vkms_device->drm, 0);
131 	if (ret)
132 		goto out_fini;
133 
134 	return 0;
135 
136 out_fini:
137 	drm_dev_fini(&vkms_device->drm);
138 
139 out_unregister:
140 	platform_device_unregister(vkms_device->platform);
141 
142 out_free:
143 	kfree(vkms_device);
144 	return ret;
145 }
146 
147 static void __exit vkms_exit(void)
148 {
149 	if (!vkms_device) {
150 		DRM_INFO("vkms_device is NULL.\n");
151 		return;
152 	}
153 
154 	drm_dev_unregister(&vkms_device->drm);
155 	drm_dev_put(&vkms_device->drm);
156 
157 	kfree(vkms_device);
158 }
159 
160 module_init(vkms_init);
161 module_exit(vkms_exit);
162 
163 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
164 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
165 MODULE_DESCRIPTION(DRIVER_DESC);
166 MODULE_LICENSE("GPL");
167