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_client_setup.h>
  20 #include <drm/drm_drv.h>
  21 #include <drm/drm_fbdev_shmem.h>
  22 #include <drm/drm_file.h>
  23 #include <drm/drm_gem_framebuffer_helper.h>
  24 #include <drm/drm_ioctl.h>
  25 #include <drm/drm_managed.h>
  26 #include <drm/drm_probe_helper.h>
  27 #include <drm/drm_gem_shmem_helper.h>
  28 #include <drm/drm_vblank.h>
  29
  30 #include "vkms_drv.h"
  31
  32 #include <drm/drm_print.h>
  33 #include <drm/drm_debugfs.h>
  34
  35 #define DRIVER_NAME     "vkms"
  36 #define DRIVER_DESC     "Virtual Kernel Mode Setting"
  37 #define DRIVER_DATE     "20180514"
  38 #define DRIVER_MAJOR    1
  39 #define DRIVER_MINOR    0
  40
  41 static struct vkms_config *default_config;
  42
  43 static bool enable_cursor = true;
  44 module_param_named(enable_cursor, enable_cursor, bool, 0444);
  45 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
  46
  47 static bool enable_writeback = true;
  48 module_param_named(enable_writeback, enable_writeback, bool, 0444);
  49 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");
  50
  51 static bool enable_overlay;
  52 module_param_named(enable_overlay, enable_overlay, bool, 0444);
  53 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
  54
  55 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
  56
  57 static void vkms_release(struct drm_device *dev)
  58 {
  59         struct vkms_device *vkms = drm_device_to_vkms_device(dev);
  60
  61         if (vkms->output.composer_workq)
  62                 destroy_workqueue(vkms->output.composer_workq);
  63 }
  64
  65 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
  66 {
  67         struct drm_device *dev = old_state->dev;
  68         struct drm_crtc *crtc;
  69         struct drm_crtc_state *old_crtc_state;
  70         int i;
  71
  72         drm_atomic_helper_commit_modeset_disables(dev, old_state);
  73
  74         drm_atomic_helper_commit_planes(dev, old_state, 0);
  75
  76         drm_atomic_helper_commit_modeset_enables(dev, old_state);
  77
  78         drm_atomic_helper_fake_vblank(old_state);
  79
  80         drm_atomic_helper_commit_hw_done(old_state);
  81
  82         drm_atomic_helper_wait_for_flip_done(dev, old_state);
  83
  84         for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
  85                 struct vkms_crtc_state *vkms_state =
  86                         to_vkms_crtc_state(old_crtc_state);
  87
  88                 flush_work(&vkms_state->composer_work);
  89         }
  90
  91         drm_atomic_helper_cleanup_planes(dev, old_state);
  92 }
  93
  94 static int vkms_config_show(struct seq_file *m, void *data)
  95 {
  96         struct drm_debugfs_entry *entry = m->private;
  97         struct drm_device *dev = entry->dev;
  98         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  99
 100         seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);
 101         seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);
 102         seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);
 103
 104         return 0;
 105 }
 106
 107 static const struct drm_debugfs_info vkms_config_debugfs_list[] = {
 108         { "vkms_config", vkms_config_show, 0 },
 109 };
 110
 111 static const struct drm_driver vkms_driver = {
 112         .driver_features        = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
 113         .release                = vkms_release,
 114         .fops                   = &vkms_driver_fops,
 115         DRM_GEM_SHMEM_DRIVER_OPS,
 116         DRM_FBDEV_SHMEM_DRIVER_OPS,
 117
 118         .name                   = DRIVER_NAME,
 119         .desc                   = DRIVER_DESC,
 120         .date                   = DRIVER_DATE,
 121         .major                  = DRIVER_MAJOR,
 122         .minor                  = DRIVER_MINOR,
 123 };
 124
 125 static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
 126 {
 127         struct drm_crtc *crtc;
 128         struct drm_crtc_state *new_crtc_state;
 129         int i;
 130
 131         for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
 132                 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed)
 133                         continue;
 134
 135                 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *)
 136                     > VKMS_LUT_SIZE)
 137                         return -EINVAL;
 138         }
 139
 140         return drm_atomic_helper_check(dev, state);
 141 }
 142
 143 static const struct drm_mode_config_funcs vkms_mode_funcs = {
 144         .fb_create = drm_gem_fb_create,
 145         .atomic_check = vkms_atomic_check,
 146         .atomic_commit = drm_atomic_helper_commit,
 147 };
 148
 149 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
 150         .atomic_commit_tail = vkms_atomic_commit_tail,
 151 };
 152
 153 static int vkms_modeset_init(struct vkms_device *vkmsdev)
 154 {
 155         struct drm_device *dev = &vkmsdev->drm;
 156         int ret;
 157
 158         ret = drmm_mode_config_init(dev);
 159         if (ret)
 160                 return ret;
 161
 162         dev->mode_config.funcs = &vkms_mode_funcs;
 163         dev->mode_config.min_width = XRES_MIN;
 164         dev->mode_config.min_height = YRES_MIN;
 165         dev->mode_config.max_width = XRES_MAX;
 166         dev->mode_config.max_height = YRES_MAX;
 167         dev->mode_config.cursor_width = 512;
 168         dev->mode_config.cursor_height = 512;
 169         /*
 170          * FIXME: There's a confusion between bpp and depth between this and
 171          * fbdev helpers. We have to go with 0, meaning "pick the default",
 172          * which is XRGB8888 in all cases.
 173          */
 174         dev->mode_config.preferred_depth = 0;
 175         dev->mode_config.helper_private = &vkms_mode_config_helpers;
 176
 177         return vkms_output_init(vkmsdev, 0);
 178 }
 179
 180 static int vkms_create(struct vkms_config *config)
 181 {
 182         int ret;
 183         struct platform_device *pdev;
 184         struct vkms_device *vkms_device;
 185
 186         pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 187         if (IS_ERR(pdev))
 188                 return PTR_ERR(pdev);
 189
 190         if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
 191                 ret = -ENOMEM;
 192                 goto out_unregister;
 193         }
 194
 195         vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
 196                                          struct vkms_device, drm);
 197         if (IS_ERR(vkms_device)) {
 198                 ret = PTR_ERR(vkms_device);
 199                 goto out_devres;
 200         }
 201         vkms_device->platform = pdev;
 202         vkms_device->config = config;
 203         config->dev = vkms_device;
 204
 205         ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 206                                            DMA_BIT_MASK(64));
 207
 208         if (ret) {
 209                 DRM_ERROR("Could not initialize DMA support\n");
 210                 goto out_devres;
 211         }
 212
 213         ret = drm_vblank_init(&vkms_device->drm, 1);
 214         if (ret) {
 215                 DRM_ERROR("Failed to vblank\n");
 216                 goto out_devres;
 217         }
 218
 219         ret = vkms_modeset_init(vkms_device);
 220         if (ret)
 221                 goto out_devres;
 222
 223         drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list,
 224                               ARRAY_SIZE(vkms_config_debugfs_list));
 225
 226         ret = drm_dev_register(&vkms_device->drm, 0);
 227         if (ret)
 228                 goto out_devres;
 229
 230         drm_client_setup(&vkms_device->drm, NULL);
 231
 232         return 0;
 233
 234 out_devres:
 235         devres_release_group(&pdev->dev, NULL);
 236 out_unregister:
 237         platform_device_unregister(pdev);
 238         return ret;
 239 }
 240
 241 static int __init vkms_init(void)
 242 {
 243         int ret;
 244         struct vkms_config *config;
 245
 246         config = kmalloc(sizeof(*config), GFP_KERNEL);
 247         if (!config)
 248                 return -ENOMEM;
 249
 250         default_config = config;
 251
 252         config->cursor = enable_cursor;
 253         config->writeback = enable_writeback;
 254         config->overlay = enable_overlay;
 255
 256         ret = vkms_create(config);
 257         if (ret)
 258                 kfree(config);
 259
 260         return ret;
 261 }
 262
 263 static void vkms_destroy(struct vkms_config *config)
 264 {
 265         struct platform_device *pdev;
 266
 267         if (!config->dev) {
 268                 DRM_INFO("vkms_device is NULL.\n");
 269                 return;
 270         }
 271
 272         pdev = config->dev->platform;
 273
 274         drm_dev_unregister(&config->dev->drm);
 275         drm_atomic_helper_shutdown(&config->dev->drm);
 276         devres_release_group(&pdev->dev, NULL);
 277         platform_device_unregister(pdev);
 278
 279         config->dev = NULL;
 280 }
 281
 282 static void __exit vkms_exit(void)
 283 {
 284         if (default_config->dev)
 285                 vkms_destroy(default_config);
 286
 287         kfree(default_config);
 288 }
 289
 290 module_init(vkms_init);
 291 module_exit(vkms_exit);
 292
 293 MODULE_AUTHOR("Haneen Mohammed <[email protected]>");
 294 MODULE_AUTHOR("Rodrigo Siqueira <[email protected]>");
 295 MODULE_DESCRIPTION(DRIVER_DESC);
 296 MODULE_LICENSE("GPL");