drivers/gpu/drm/vkms/vkms_drv.c

   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.h>
  15 #include <drm/drm_atomic_helper.h>
  16 #include <drm/drm_gem_framebuffer_helper.h>
  17 #include <drm/drm_fb_helper.h>
  18 #include <drm/drm_probe_helper.h>
  19 #include "vkms_drv.h"
  20
  21 #define DRIVER_NAME     "vkms"
  22 #define DRIVER_DESC     "Virtual Kernel Mode Setting"
  23 #define DRIVER_DATE     "20180514"
  24 #define DRIVER_MAJOR    1
  25 #define DRIVER_MINOR    0
  26
  27 static struct vkms_device *vkms_device;
  28
  29 bool enable_cursor;
  30 module_param_named(enable_cursor, enable_cursor, bool, 0444);
  31 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
  32
  33 static const struct file_operations vkms_driver_fops = {
  34         .owner          = THIS_MODULE,
  35         .open           = drm_open,
  36         .mmap           = drm_gem_mmap,
  37         .unlocked_ioctl = drm_ioctl,
  38         .compat_ioctl   = drm_compat_ioctl,
  39         .poll           = drm_poll,
  40         .read           = drm_read,
  41         .llseek         = no_llseek,
  42         .release        = drm_release,
  43 };
  44
  45 static const struct vm_operations_struct vkms_gem_vm_ops = {
  46         .fault = vkms_gem_fault,
  47         .open = drm_gem_vm_open,
  48         .close = drm_gem_vm_close,
  49 };
  50
  51 static void vkms_release(struct drm_device *dev)
  52 {
  53         struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
  54
  55         platform_device_unregister(vkms->platform);
  56         drm_atomic_helper_shutdown(&vkms->drm);
  57         drm_mode_config_cleanup(&vkms->drm);
  58         drm_dev_fini(&vkms->drm);
  59         destroy_workqueue(vkms->output.composer_workq);
  60 }
  61
  62 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
  63 {
  64         struct drm_device *dev = old_state->dev;
  65         struct drm_crtc *crtc;
  66         struct drm_crtc_state *old_crtc_state;
  67         int i;
  68
  69         drm_atomic_helper_commit_modeset_disables(dev, old_state);
  70
  71         drm_atomic_helper_commit_planes(dev, old_state, 0);
  72
  73         drm_atomic_helper_commit_modeset_enables(dev, old_state);
  74
  75         drm_atomic_helper_fake_vblank(old_state);
  76
  77         drm_atomic_helper_commit_hw_done(old_state);
  78
  79         drm_atomic_helper_wait_for_vblanks(dev, old_state);
  80
  81         for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
  82                 struct vkms_crtc_state *vkms_state =
  83                         to_vkms_crtc_state(old_crtc_state);
  84
  85                 flush_work(&vkms_state->composer_work);
  86         }
  87
  88         drm_atomic_helper_cleanup_planes(dev, old_state);
  89 }
  90
  91 static struct drm_driver vkms_driver = {
  92         .driver_features        = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
  93         .release                = vkms_release,
  94         .fops                   = &vkms_driver_fops,
  95         .dumb_create            = vkms_dumb_create,
  96         .gem_vm_ops             = &vkms_gem_vm_ops,
  97         .gem_free_object_unlocked = vkms_gem_free_object,
  98         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
  99
 100         .name                   = DRIVER_NAME,
 101         .desc                   = DRIVER_DESC,
 102         .date                   = DRIVER_DATE,
 103         .major                  = DRIVER_MAJOR,
 104         .minor                  = DRIVER_MINOR,
 105 };
 106
 107 static const struct drm_mode_config_funcs vkms_mode_funcs = {
 108         .fb_create = drm_gem_fb_create,
 109         .atomic_check = drm_atomic_helper_check,
 110         .atomic_commit = drm_atomic_helper_commit,
 111 };
 112
 113 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
 114         .atomic_commit_tail = vkms_atomic_commit_tail,
 115 };
 116
 117 static int vkms_modeset_init(struct vkms_device *vkmsdev)
 118 {
 119         struct drm_device *dev = &vkmsdev->drm;
 120
 121         drm_mode_config_init(dev);
 122         dev->mode_config.funcs = &vkms_mode_funcs;
 123         dev->mode_config.min_width = XRES_MIN;
 124         dev->mode_config.min_height = YRES_MIN;
 125         dev->mode_config.max_width = XRES_MAX;
 126         dev->mode_config.max_height = YRES_MAX;
 127         dev->mode_config.preferred_depth = 24;
 128         dev->mode_config.helper_private = &vkms_mode_config_helpers;
 129
 130         return vkms_output_init(vkmsdev, 0);
 131 }
 132
 133 static int __init vkms_init(void)
 134 {
 135         int ret;
 136
 137         vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
 138         if (!vkms_device)
 139                 return -ENOMEM;
 140
 141         vkms_device->platform =
 142                 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 143         if (IS_ERR(vkms_device->platform)) {
 144                 ret = PTR_ERR(vkms_device->platform);
 145                 goto out_free;
 146         }
 147
 148         ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
 149                            &vkms_device->platform->dev);
 150         if (ret)
 151                 goto out_unregister;
 152
 153         vkms_device->drm.irq_enabled = true;
 154
 155         ret = drm_vblank_init(&vkms_device->drm, 1);
 156         if (ret) {
 157                 DRM_ERROR("Failed to vblank\n");
 158                 goto out_fini;
 159         }
 160
 161         ret = vkms_modeset_init(vkms_device);
 162         if (ret)
 163                 goto out_fini;
 164
 165         ret = drm_dev_register(&vkms_device->drm, 0);
 166         if (ret)
 167                 goto out_fini;
 168
 169         return 0;
 170
 171 out_fini:
 172         drm_dev_fini(&vkms_device->drm);
 173
 174 out_unregister:
 175         platform_device_unregister(vkms_device->platform);
 176
 177 out_free:
 178         kfree(vkms_device);
 179         return ret;
 180 }
 181
 182 static void __exit vkms_exit(void)
 183 {
 184         if (!vkms_device) {
 185                 DRM_INFO("vkms_device is NULL.\n");
 186                 return;
 187         }
 188
 189         drm_dev_unregister(&vkms_device->drm);
 190         drm_dev_put(&vkms_device->drm);
 191
 192         kfree(vkms_device);
 193 }
 194
 195 module_init(vkms_init);
 196 module_exit(vkms_exit);
 197
 198 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
 199 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
 200 MODULE_DESCRIPTION(DRIVER_DESC);
 201 MODULE_LICENSE("GPL");