Commit 1c7c5fd9 authored by Haneen Mohammed's avatar Haneen Mohammed Committed by Gustavo Padovan

drm/vkms: Introduce basic VKMS driver

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: default avatarHaneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180514143346.GA21695@haneen-vb
parent c51756d5
......@@ -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"
......
......@@ -69,6 +69,7 @@ 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/
......
vkms-y := vkms_drv.o
obj-$(CONFIG_DRM_VKMS) += vkms.o
/*
* 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");
#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_ */
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