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_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");