295 lines · 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 testing7 * and for running X (or similar) on headless machines. VKMS aims to enable8 * a virtual display with no need of a hardware display capability, releasing9 * 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_fbdev_shmem.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#include <drm/drm_print.h>32#include <drm/drm_debugfs.h>33 34#define DRIVER_NAME "vkms"35#define DRIVER_DESC "Virtual Kernel Mode Setting"36#define DRIVER_DATE "20180514"37#define DRIVER_MAJOR 138#define DRIVER_MINOR 039 40static struct vkms_config *default_config;41 42static bool enable_cursor = true;43module_param_named(enable_cursor, enable_cursor, bool, 0444);44MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");45 46static bool enable_writeback = true;47module_param_named(enable_writeback, enable_writeback, bool, 0444);48MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");49 50static bool enable_overlay;51module_param_named(enable_overlay, enable_overlay, bool, 0444);52MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");53 54DEFINE_DRM_GEM_FOPS(vkms_driver_fops);55 56static void vkms_release(struct drm_device *dev)57{58 struct vkms_device *vkms = drm_device_to_vkms_device(dev);59 60 if (vkms->output.composer_workq)61 destroy_workqueue(vkms->output.composer_workq);62}63 64static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)65{66 struct drm_device *dev = old_state->dev;67 struct drm_crtc *crtc;68 struct drm_crtc_state *old_crtc_state;69 int i;70 71 drm_atomic_helper_commit_modeset_disables(dev, old_state);72 73 drm_atomic_helper_commit_planes(dev, old_state, 0);74 75 drm_atomic_helper_commit_modeset_enables(dev, old_state);76 77 drm_atomic_helper_fake_vblank(old_state);78 79 drm_atomic_helper_commit_hw_done(old_state);80 81 drm_atomic_helper_wait_for_flip_done(dev, old_state);82 83 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {84 struct vkms_crtc_state *vkms_state =85 to_vkms_crtc_state(old_crtc_state);86 87 flush_work(&vkms_state->composer_work);88 }89 90 drm_atomic_helper_cleanup_planes(dev, old_state);91}92 93static int vkms_config_show(struct seq_file *m, void *data)94{95 struct drm_debugfs_entry *entry = m->private;96 struct drm_device *dev = entry->dev;97 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);98 99 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);100 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);101 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);102 103 return 0;104}105 106static const struct drm_debugfs_info vkms_config_debugfs_list[] = {107 { "vkms_config", vkms_config_show, 0 },108};109 110static const struct drm_driver vkms_driver = {111 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,112 .release = vkms_release,113 .fops = &vkms_driver_fops,114 DRM_GEM_SHMEM_DRIVER_OPS,115 116 .name = DRIVER_NAME,117 .desc = DRIVER_DESC,118 .date = DRIVER_DATE,119 .major = DRIVER_MAJOR,120 .minor = DRIVER_MINOR,121};122 123static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)124{125 struct drm_crtc *crtc;126 struct drm_crtc_state *new_crtc_state;127 int i;128 129 for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {130 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed)131 continue;132 133 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *)134 > VKMS_LUT_SIZE)135 return -EINVAL;136 }137 138 return drm_atomic_helper_check(dev, state);139}140 141static const struct drm_mode_config_funcs vkms_mode_funcs = {142 .fb_create = drm_gem_fb_create,143 .atomic_check = vkms_atomic_check,144 .atomic_commit = drm_atomic_helper_commit,145};146 147static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {148 .atomic_commit_tail = vkms_atomic_commit_tail,149};150 151static int vkms_modeset_init(struct vkms_device *vkmsdev)152{153 struct drm_device *dev = &vkmsdev->drm;154 int ret;155 156 ret = drmm_mode_config_init(dev);157 if (ret)158 return ret;159 160 dev->mode_config.funcs = &vkms_mode_funcs;161 dev->mode_config.min_width = XRES_MIN;162 dev->mode_config.min_height = YRES_MIN;163 dev->mode_config.max_width = XRES_MAX;164 dev->mode_config.max_height = YRES_MAX;165 dev->mode_config.cursor_width = 512;166 dev->mode_config.cursor_height = 512;167 /*168 * FIXME: There's a confusion between bpp and depth between this and169 * fbdev helpers. We have to go with 0, meaning "pick the default",170 * which is XRGB8888 in all cases.171 */172 dev->mode_config.preferred_depth = 0;173 dev->mode_config.helper_private = &vkms_mode_config_helpers;174 175 return vkms_output_init(vkmsdev, 0);176}177 178static int vkms_create(struct vkms_config *config)179{180 int ret;181 struct platform_device *pdev;182 struct vkms_device *vkms_device;183 184 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);185 if (IS_ERR(pdev))186 return PTR_ERR(pdev);187 188 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {189 ret = -ENOMEM;190 goto out_unregister;191 }192 193 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,194 struct vkms_device, drm);195 if (IS_ERR(vkms_device)) {196 ret = PTR_ERR(vkms_device);197 goto out_devres;198 }199 vkms_device->platform = pdev;200 vkms_device->config = config;201 config->dev = vkms_device;202 203 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,204 DMA_BIT_MASK(64));205 206 if (ret) {207 DRM_ERROR("Could not initialize DMA support\n");208 goto out_devres;209 }210 211 ret = drm_vblank_init(&vkms_device->drm, 1);212 if (ret) {213 DRM_ERROR("Failed to vblank\n");214 goto out_devres;215 }216 217 ret = vkms_modeset_init(vkms_device);218 if (ret)219 goto out_devres;220 221 drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list,222 ARRAY_SIZE(vkms_config_debugfs_list));223 224 ret = drm_dev_register(&vkms_device->drm, 0);225 if (ret)226 goto out_devres;227 228 drm_fbdev_shmem_setup(&vkms_device->drm, 0);229 230 return 0;231 232out_devres:233 devres_release_group(&pdev->dev, NULL);234out_unregister:235 platform_device_unregister(pdev);236 return ret;237}238 239static int __init vkms_init(void)240{241 int ret;242 struct vkms_config *config;243 244 config = kmalloc(sizeof(*config), GFP_KERNEL);245 if (!config)246 return -ENOMEM;247 248 default_config = config;249 250 config->cursor = enable_cursor;251 config->writeback = enable_writeback;252 config->overlay = enable_overlay;253 254 ret = vkms_create(config);255 if (ret)256 kfree(config);257 258 return ret;259}260 261static void vkms_destroy(struct vkms_config *config)262{263 struct platform_device *pdev;264 265 if (!config->dev) {266 DRM_INFO("vkms_device is NULL.\n");267 return;268 }269 270 pdev = config->dev->platform;271 272 drm_dev_unregister(&config->dev->drm);273 drm_atomic_helper_shutdown(&config->dev->drm);274 devres_release_group(&pdev->dev, NULL);275 platform_device_unregister(pdev);276 277 config->dev = NULL;278}279 280static void __exit vkms_exit(void)281{282 if (default_config->dev)283 vkms_destroy(default_config);284 285 kfree(default_config);286}287 288module_init(vkms_init);289module_exit(vkms_exit);290 291MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");292MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");293MODULE_DESCRIPTION(DRIVER_DESC);294MODULE_LICENSE("GPL");295