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  * 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
  36 static struct vkms_device *vkms_device;
  37
  38 bool enable_cursor = true;
  39 module_param_named(enable_cursor, enable_cursor, bool, 0444);
  40 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
  41
  42 static 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
  54 static 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
  60 static void vkms_release(struct drm_device *dev)
  61 {
  62         struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
  63
  64         destroy_workqueue(vkms->output.composer_workq);
  65 }
  66
  67 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
  68 {
  69         struct drm_device *dev = old_state->dev;
  70         struct drm_crtc *crtc;
  71         struct drm_crtc_state *old_crtc_state;
  72         int i;
  73
  74         drm_atomic_helper_commit_modeset_disables(dev, old_state);
  75
  76         drm_atomic_helper_commit_planes(dev, old_state, 0);
  77
  78         drm_atomic_helper_commit_modeset_enables(dev, old_state);
  79
  80         drm_atomic_helper_fake_vblank(old_state);
  81
  82         drm_atomic_helper_commit_hw_done(old_state);
  83
  84         drm_atomic_helper_wait_for_flip_done(dev, old_state);
  85
  86         for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
  87                 struct vkms_crtc_state *vkms_state =
  88                         to_vkms_crtc_state(old_crtc_state);
  89
  90                 flush_work(&vkms_state->composer_work);
  91         }
  92
  93         drm_atomic_helper_cleanup_planes(dev, old_state);
  94 }
  95
  96 static struct drm_driver vkms_driver = {
  97         .driver_features        = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
  98         .release                = vkms_release,
  99         .fops                   = &vkms_driver_fops,
 100         .dumb_create            = vkms_dumb_create,
 101         .gem_vm_ops             = &vkms_gem_vm_ops,
 102         .gem_free_object_unlocked = vkms_gem_free_object,
 103         .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
 104         .gem_prime_import_sg_table = vkms_prime_import_sg_table,
 105
 106         .name                   = DRIVER_NAME,
 107         .desc                   = DRIVER_DESC,
 108         .date                   = DRIVER_DATE,
 109         .major                  = DRIVER_MAJOR,
 110         .minor                  = DRIVER_MINOR,
 111 };
 112
 113 static const struct drm_mode_config_funcs vkms_mode_funcs = {
 114         .fb_create = drm_gem_fb_create,
 115         .atomic_check = drm_atomic_helper_check,
 116         .atomic_commit = drm_atomic_helper_commit,
 117 };
 118
 119 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
 120         .atomic_commit_tail = vkms_atomic_commit_tail,
 121 };
 122
 123 static int vkms_modeset_init(struct vkms_device *vkmsdev)
 124 {
 125         struct drm_device *dev = &vkmsdev->drm;
 126
 127         drm_mode_config_init(dev);
 128         dev->mode_config.funcs = &vkms_mode_funcs;
 129         dev->mode_config.min_width = XRES_MIN;
 130         dev->mode_config.min_height = YRES_MIN;
 131         dev->mode_config.max_width = XRES_MAX;
 132         dev->mode_config.max_height = YRES_MAX;
 133         dev->mode_config.cursor_width = 512;
 134         dev->mode_config.cursor_height = 512;
 135         dev->mode_config.preferred_depth = 24;
 136         dev->mode_config.helper_private = &vkms_mode_config_helpers;
 137
 138         return vkms_output_init(vkmsdev, 0);
 139 }
 140
 141 static int __init vkms_init(void)
 142 {
 143         int ret;
 144         struct platform_device *pdev;
 145
 146         pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 147         if (IS_ERR(pdev))
 148                 return PTR_ERR(pdev);
 149
 150         if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
 151                 ret = -ENOMEM;
 152                 goto out_unregister;
 153         }
 154
 155         vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
 156                                          struct vkms_device, drm);
 157         if (IS_ERR(vkms_device)) {
 158                 ret = PTR_ERR(vkms_device);
 159                 goto out_devres;
 160         }
 161         vkms_device->platform = pdev;
 162
 163         ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 164                                            DMA_BIT_MASK(64));
 165
 166         if (ret) {
 167                 DRM_ERROR("Could not initialize DMA support\n");
 168                 goto out_devres;
 169         }
 170
 171         vkms_device->drm.irq_enabled = true;
 172
 173         ret = drm_vblank_init(&vkms_device->drm, 1);
 174         if (ret) {
 175                 DRM_ERROR("Failed to vblank\n");
 176                 goto out_devres;
 177         }
 178
 179         ret = vkms_modeset_init(vkms_device);
 180         if (ret)
 181                 goto out_devres;
 182
 183         ret = drm_dev_register(&vkms_device->drm, 0);
 184         if (ret)
 185                 goto out_devres;
 186
 187         return 0;
 188
 189 out_devres:
 190         devres_release_group(&pdev->dev, NULL);
 191 out_unregister:
 192         platform_device_unregister(pdev);
 193         return ret;
 194 }
 195
 196 static void __exit vkms_exit(void)
 197 {
 198         struct platform_device *pdev;
 199
 200         if (!vkms_device) {
 201                 DRM_INFO("vkms_device is NULL.\n");
 202                 return;
 203         }
 204
 205         pdev = vkms_device->platform;
 206
 207         drm_dev_unregister(&vkms_device->drm);
 208         drm_atomic_helper_shutdown(&vkms_device->drm);
 209         devres_release_group(&pdev->dev, NULL);
 210         platform_device_unregister(pdev);
 211 }
 212
 213 module_init(vkms_init);
 214 module_exit(vkms_exit);
 215
 216 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
 217 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
 218 MODULE_DESCRIPTION(DRIVER_DESC);
 219 MODULE_LICENSE("GPL");