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_gem_shmem_helper.h>
  27 #include <drm/drm_vblank.h>
  28
  29 #include "vkms_drv.h"
  30
  31 #define DRIVER_NAME     "vkms"
  32 #define DRIVER_DESC     "Virtual Kernel Mode Setting"
  33 #define DRIVER_DATE     "20180514"
  34 #define DRIVER_MAJOR    1
  35 #define DRIVER_MINOR    0
  36
  37 static struct vkms_device *vkms_device;
  38
  39 bool enable_cursor = true;
  40 module_param_named(enable_cursor, enable_cursor, bool, 0444);
  41 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
  42
  43 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
  44
  45 static void vkms_release(struct drm_device *dev)
  46 {
  47         struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
  48
  49         destroy_workqueue(vkms->output.composer_workq);
  50 }
  51
  52 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
  53 {
  54         struct drm_device *dev = old_state->dev;
  55         struct drm_crtc *crtc;
  56         struct drm_crtc_state *old_crtc_state;
  57         int i;
  58
  59         drm_atomic_helper_commit_modeset_disables(dev, old_state);
  60
  61         drm_atomic_helper_commit_planes(dev, old_state, 0);
  62
  63         drm_atomic_helper_commit_modeset_enables(dev, old_state);
  64
  65         drm_atomic_helper_fake_vblank(old_state);
  66
  67         drm_atomic_helper_commit_hw_done(old_state);
  68
  69         drm_atomic_helper_wait_for_flip_done(dev, old_state);
  70
  71         for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
  72                 struct vkms_crtc_state *vkms_state =
  73                         to_vkms_crtc_state(old_crtc_state);
  74
  75                 flush_work(&vkms_state->composer_work);
  76         }
  77
  78         drm_atomic_helper_cleanup_planes(dev, old_state);
  79 }
  80
  81 static const struct drm_driver vkms_driver = {
  82         .driver_features        = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
  83         .release                = vkms_release,
  84         .fops                   = &vkms_driver_fops,
  85         DRM_GEM_SHMEM_DRIVER_OPS,
  86
  87         .name                   = DRIVER_NAME,
  88         .desc                   = DRIVER_DESC,
  89         .date                   = DRIVER_DATE,
  90         .major                  = DRIVER_MAJOR,
  91         .minor                  = DRIVER_MINOR,
  92 };
  93
  94 static const struct drm_mode_config_funcs vkms_mode_funcs = {
  95         .fb_create = drm_gem_fb_create,
  96         .atomic_check = drm_atomic_helper_check,
  97         .atomic_commit = drm_atomic_helper_commit,
  98 };
  99
 100 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
 101         .atomic_commit_tail = vkms_atomic_commit_tail,
 102 };
 103
 104 static int vkms_modeset_init(struct vkms_device *vkmsdev)
 105 {
 106         struct drm_device *dev = &vkmsdev->drm;
 107
 108         drm_mode_config_init(dev);
 109         dev->mode_config.funcs = &vkms_mode_funcs;
 110         dev->mode_config.min_width = XRES_MIN;
 111         dev->mode_config.min_height = YRES_MIN;
 112         dev->mode_config.max_width = XRES_MAX;
 113         dev->mode_config.max_height = YRES_MAX;
 114         dev->mode_config.cursor_width = 512;
 115         dev->mode_config.cursor_height = 512;
 116         dev->mode_config.preferred_depth = 32;
 117         dev->mode_config.helper_private = &vkms_mode_config_helpers;
 118
 119         return vkms_output_init(vkmsdev, 0);
 120 }
 121
 122 static int __init vkms_init(void)
 123 {
 124         int ret;
 125         struct platform_device *pdev;
 126
 127         pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 128         if (IS_ERR(pdev))
 129                 return PTR_ERR(pdev);
 130
 131         if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
 132                 ret = -ENOMEM;
 133                 goto out_unregister;
 134         }
 135
 136         vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
 137                                          struct vkms_device, drm);
 138         if (IS_ERR(vkms_device)) {
 139                 ret = PTR_ERR(vkms_device);
 140                 goto out_devres;
 141         }
 142         vkms_device->platform = pdev;
 143
 144         ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 145                                            DMA_BIT_MASK(64));
 146
 147         if (ret) {
 148                 DRM_ERROR("Could not initialize DMA support\n");
 149                 goto out_devres;
 150         }
 151
 152         vkms_device->drm.irq_enabled = true;
 153
 154         ret = drm_vblank_init(&vkms_device->drm, 1);
 155         if (ret) {
 156                 DRM_ERROR("Failed to vblank\n");
 157                 goto out_devres;
 158         }
 159
 160         ret = vkms_modeset_init(vkms_device);
 161         if (ret)
 162                 goto out_devres;
 163
 164         ret = drm_dev_register(&vkms_device->drm, 0);
 165         if (ret)
 166                 goto out_devres;
 167
 168         drm_fbdev_generic_setup(&vkms_device->drm, 0);
 169
 170         return 0;
 171
 172 out_devres:
 173         devres_release_group(&pdev->dev, NULL);
 174 out_unregister:
 175         platform_device_unregister(pdev);
 176         return ret;
 177 }
 178
 179 static void __exit vkms_exit(void)
 180 {
 181         struct platform_device *pdev;
 182
 183         if (!vkms_device) {
 184                 DRM_INFO("vkms_device is NULL.\n");
 185                 return;
 186         }
 187
 188         pdev = vkms_device->platform;
 189
 190         drm_dev_unregister(&vkms_device->drm);
 191         drm_atomic_helper_shutdown(&vkms_device->drm);
 192         devres_release_group(&pdev->dev, NULL);
 193         platform_device_unregister(pdev);
 194 }
 195
 196 module_init(vkms_init);
 197 module_exit(vkms_exit);
 198
 199 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
 200 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
 201 MODULE_DESCRIPTION(DRIVER_DESC);
 202 MODULE_LICENSE("GPL");