From: Haneen Mohammed <hamohammed.sa@gmail.com>
Date: Mon, 14 May 2018 17:33:46 +0300
Subject: drm/vkms: Introduce basic VKMS driver
Git-commit: 1c7c5fd916a0ff66501467f1e8e79d3ff8eca112
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
This patch introduces Virtual Kernel Mode-Setting (VKMS) driver. It
creates a very basic kms driver with 1 crtc/encoder/connector/plane.
VKMS driver would be useful for testing, or for running X (or similar)
on headless machines and be able to still use the GPU. Thus it enables
a virtual display without the need for hardware display capability.
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180514143346.GA21695@haneen-vb
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/Kconfig | 6 +
drivers/gpu/drm/Makefile | 1
drivers/gpu/drm/vkms/Makefile | 3
drivers/gpu/drm/vkms/vkms_drv.c | 146 ++++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/vkms/vkms_drv.h | 13 +++
5 files changed, 169 insertions(+)
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -213,6 +213,12 @@ config DRM_VGEM
as used by Mesa's software renderer for enhanced performance.
If M is selected the module will be called vgem.
+config DRM_VKMS
+ tristate "Virtual KMS"
+ depends on DRM
+ help
+ Choose this option to get a virtual kernal mode-setting driver.
+ If M is selected the module will be called vkms.
source "drivers/gpu/drm/exynos/Kconfig"
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_DRM_SAVAGE)+= savage/
obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
obj-$(CONFIG_DRM_VIA) +=via/
obj-$(CONFIG_DRM_VGEM) += vgem/
+obj-$(CONFIG_DRM_VKMS) += vkms/
obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
obj-$(CONFIG_DRM_EXYNOS) +=exynos/
obj-$(CONFIG_DRM_ROCKCHIP) +=rockchip/
--- /dev/null
+++ b/drivers/gpu/drm/vkms/Makefile
@@ -0,0 +1,3 @@
+vkms-y := vkms_drv.o
+
+obj-$(CONFIG_DRM_VKMS) += vkms.o
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -0,0 +1,146 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_crtc_helper.h>
+#include "vkms_drv.h"
+
+#define DRIVER_NAME "vkms"
+#define DRIVER_DESC "Virtual Kernel Mode Setting"
+#define DRIVER_DATE "20180514"
+#define DRIVER_MAJOR 1
+#define DRIVER_MINOR 0
+
+static struct vkms_device *vkms_device;
+
+static const struct file_operations vkms_driver_fops = {
+ .owner = THIS_MODULE,
+ .open = drm_open,
+ .mmap = drm_gem_mmap,
+ .unlocked_ioctl = drm_ioctl,
+ .compat_ioctl = drm_compat_ioctl,
+ .poll = drm_poll,
+ .read = drm_read,
+ .llseek = no_llseek,
+ .release = drm_release,
+};
+
+static void vkms_release(struct drm_device *dev)
+{
+ struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
+
+ platform_device_unregister(vkms->platform);
+ drm_mode_config_cleanup(&vkms->drm);
+ drm_dev_fini(&vkms->drm);
+}
+
+struct drm_driver vkms_driver = {
+ .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
+ .release = vkms_release,
+ .fops = &vkms_driver_fops,
+
+ .name = DRIVER_NAME,
+ .desc = DRIVER_DESC,
+ .date = DRIVER_DATE,
+ .major = DRIVER_MAJOR,
+ .minor = DRIVER_MINOR,
+};
+
+static const u32 vkms_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static void vkms_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_unregister(connector);
+ drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs vkms_connector_funcs = {
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = vkms_connector_destroy,
+};
+
+static int __init vkms_init(void)
+{
+ int ret;
+
+ vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
+ if (!vkms_device)
+ return -ENOMEM;
+
+ ret = drm_dev_init(&vkms_device->drm, &vkms_driver, NULL);
+ if (ret)
+ goto out_free;
+
+ vkms_device->platform =
+ platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
+ if (IS_ERR(vkms_device->platform)) {
+ ret = PTR_ERR(vkms_device->platform);
+ goto out_fini;
+ }
+
+ drm_mode_config_init(&vkms_device->drm);
+
+ ret = drm_connector_init(&vkms_device->drm, &vkms_device->connector,
+ &vkms_connector_funcs,
+ DRM_MODE_CONNECTOR_VIRTUAL);
+ if (ret < 0) {
+ DRM_ERROR("Failed to init connector\n");
+ goto out_unregister;
+ }
+
+ ret = drm_simple_display_pipe_init(&vkms_device->drm,
+ &vkms_device->pipe,
+ NULL,
+ vkms_formats,
+ ARRAY_SIZE(vkms_formats),
+ NULL,
+ &vkms_device->connector);
+ if (ret < 0) {
+ DRM_ERROR("Cannot setup simple display pipe\n");
+ goto out_unregister;
+ }
+
+ ret = drm_dev_register(&vkms_device->drm, 0);
+ if (ret)
+ goto out_unregister;
+
+ drm_connector_register(&vkms_device->connector);
+
+ return 0;
+
+out_unregister:
+ platform_device_unregister(vkms_device->platform);
+out_fini:
+ drm_dev_fini(&vkms_device->drm);
+out_free:
+ kfree(vkms_device);
+
+ return ret;
+}
+
+static void __exit vkms_exit(void)
+{
+ if (!vkms_device) {
+ DRM_INFO("vkms_device is NULL.\n");
+ return;
+ }
+
+ drm_dev_unregister(&vkms_device->drm);
+ drm_dev_put(&vkms_device->drm);
+
+ kfree(vkms_device);
+}
+
+module_init(vkms_init);
+module_exit(vkms_exit);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -0,0 +1,13 @@
+#ifndef _VKMS_DRV_H_
+#define _VKMS_DRV_H_
+
+#include <drm/drm_simple_kms_helper.h>
+
+struct vkms_device {
+ struct drm_device drm;
+ struct platform_device *platform;
+ struct drm_simple_display_pipe pipe;
+ struct drm_connector connector;
+};
+
+#endif /* _VKMS_DRV_H_ */