Re: [PATCH v2 4/6] drm/vs: Register DRM device

From: Dmitry Baryshkov
Date: Wed Oct 25 2023 - 11:51:04 EST

On 25/10/2023 13:39, Keith Zhao wrote:
Implement drm device registration interface

Thomas Zimmermann wrote:
You are replacing almost all of the GEM DMA object's helper code.
Either inherit directly from drm_gem_object drop the dependency entirely,
or you could try to fit your code into GEM DMA as well

Eventually I found an answer and it was DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE
After I adapt this interface, the custom gem logic interfaces can be deleted.
It's a big shocking, clap!

Signed-off-by: Keith Zhao <keith.zhao@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/Kconfig | 2 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/verisilicon/Kconfig | 15 ++
drivers/gpu/drm/verisilicon/Makefile | 7 +
drivers/gpu/drm/verisilicon/vs_drv.c | 227 +++++++++++++++++++++++
drivers/gpu/drm/verisilicon/vs_drv.h | 27 +++
drivers/gpu/drm/verisilicon/vs_modeset.c | 36 ++++
drivers/gpu/drm/verisilicon/vs_modeset.h | 10 +
include/uapi/drm/vs_drm.h | 50 +++++
9 files changed, 375 insertions(+)
create mode 100644 drivers/gpu/drm/verisilicon/Kconfig
create mode 100644 drivers/gpu/drm/verisilicon/Makefile
create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.c
create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.h
create mode 100644 drivers/gpu/drm/verisilicon/vs_modeset.c
create mode 100644 drivers/gpu/drm/verisilicon/vs_modeset.h
create mode 100644 include/uapi/drm/vs_drm.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index afb3b2f5f..9ede80ef9 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -363,6 +363,8 @@ source "drivers/gpu/drm/solomon/Kconfig"
source "drivers/gpu/drm/sprd/Kconfig"
+source "drivers/gpu/drm/verisilicon/Kconfig"
+
config DRM_HYPERV
tristate "DRM Support for Hyper-V synthetic video device"
depends on DRM && PCI && MMU && HYPERV
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 7a09a89b4..6db3bc397 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -194,3 +194,4 @@ obj-y += gud/
obj-$(CONFIG_DRM_HYPERV) += hyperv/
obj-y += solomon/
obj-$(CONFIG_DRM_SPRD) += sprd/
+obj-$(CONFIG_DRM_VERISILICON) += verisilicon/
diff --git a/drivers/gpu/drm/verisilicon/Kconfig b/drivers/gpu/drm/verisilicon/Kconfig
new file mode 100644
index 000000000..3a361f8c8
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+config DRM_VERISILICON
+ tristate "DRM Support for VeriSilicon"
+ depends on DRM
+ select DRM_KMS_HELPER
+ select DRM_GEM_DMA_HELPER
+ select CMA
+ select DMA_CMA
+ help
+ Choose this option if you have a VeriSilicon soc chipset.
+ This driver provides VeriSilicon kernel mode
+ setting and buffer management. It does not
+ provide 2D or 3D acceleration.
+
+
diff --git a/drivers/gpu/drm/verisilicon/Makefile b/drivers/gpu/drm/verisilicon/Makefile
new file mode 100644
index 000000000..7d3be305b
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+vs_drm-objs := vs_drv.o \
+ vs_modeset.o
+
+obj-$(CONFIG_DRM_VERISILICON) += vs_drm.o
+
diff --git a/drivers/gpu/drm/verisilicon/vs_drv.c b/drivers/gpu/drm/verisilicon/vs_drv.c
new file mode 100644
index 000000000..da7698c3d
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/vs_drv.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
+ */
+
+#include <linux/component.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_aperture.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fbdev_generic.h>
+#include <drm/drm_file.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_module.h>
+#include <drm/drm_of.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "vs_drv.h"
+#include "vs_modeset.h"
+
+#define DRV_NAME "verisilicon"
+#define DRV_DESC "Verisilicon DRM driver"
+#define DRV_DATE "20230516"
+#define DRV_MAJOR 1
+#define DRV_MINOR 0
+
+static int vs_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
+ struct drm_mode_create_dumb *args)
+{
+ struct vs_drm_device *priv = to_vs_drm_private(dev);
+
+ unsigned int pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+
+ if (args->bpp % 10)
+ args->pitch = ALIGN(pitch, priv->pitch_alignment);
+ else
+ /* for costum 10bit format with no bit gaps */

? I think you meant 'custom' here. If so, please define that format and use it explicitly here. There can be other 10bpp formats.

+ args->pitch = pitch;
+
+ return drm_gem_dma_dumb_create_internal(file, dev, args);
+}
+
+DEFINE_DRM_GEM_FOPS(vs_drm_fops);
+
+static struct drm_driver vs_drm_driver = {
+ .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
+
+ DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(vs_gem_dumb_create),
+
+ .fops = &vs_drm_fops,
+ .name = DRV_NAME,
+ .desc = DRV_DESC,
+ .date = DRV_DATE,
+ .major = DRV_MAJOR,
+ .minor = DRV_MINOR,
+};
+
+static int vs_drm_bind(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct vs_drm_device *priv;
+ int ret;
+ struct drm_device *drm_dev;
+
+ /* Remove existing drivers that may own the framebuffer memory. */
+ ret = drm_aperture_remove_framebuffers(&vs_drm_driver);
+ if (ret)
+ return ret;
+
+ priv = devm_drm_dev_alloc(dev, &vs_drm_driver, struct vs_drm_device, base);
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);
+
+ priv->pitch_alignment = 64;
+
+ ret = dma_set_coherent_mask(priv->base.dev, DMA_BIT_MASK(40));
+ if (ret)
+ return ret;
+
+ drm_dev = &priv->base;
+ platform_set_drvdata(pdev, drm_dev);
+
+ vs_mode_config_init(drm_dev);
+
+ /* Now try and bind all our sub-components */
+ ret = component_bind_all(dev, drm_dev);
+ if (ret)
+ return ret;
+
+ ret = drm_vblank_init(drm_dev, drm_dev->mode_config.num_crtc);
+ if (ret)
+ return ret;
+
+ drm_mode_config_reset(drm_dev);
+
+ drm_kms_helper_poll_init(drm_dev);
+
+ ret = drm_dev_register(drm_dev, 0);
+ if (ret)
+ return ret;
+
+ drm_fbdev_generic_setup(drm_dev, 32);
+
+ return 0;
+}
+
+static void vs_drm_unbind(struct device *dev)
+{
+ struct drm_device *drm_dev = dev_get_drvdata(dev);
+
+ drm_dev_unregister(drm_dev);
+ drm_kms_helper_poll_fini(drm_dev);
+ component_unbind_all(drm_dev->dev, drm_dev);
+}
+
+static const struct component_master_ops vs_drm_ops = {
+ .bind = vs_drm_bind,
+ .unbind = vs_drm_unbind,
+};
+
+static struct platform_driver *drm_sub_drivers[] = {
+
+};
+
+static struct component_match *vs_drm_match_add(struct device *dev)
+{
+ struct component_match *match = NULL;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(drm_sub_drivers); ++i) {
+ struct platform_driver *drv = drm_sub_drivers[i];
+ struct device *p = NULL, *d;
+
+ while ((d = platform_find_device_by_driver(p, &drv->driver))) {
+ put_device(p);
+
+ component_match_add(dev, &match, component_compare_dev, d);

drm_of_component_match_add ?

+ p = d;
+ }
+ put_device(p);
+ }
+
+ return match ? match : ERR_PTR(-ENODEV);
+}
+
+static int vs_drm_platform_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct component_match *match;
+
+ match = vs_drm_match_add(dev);
+ if (IS_ERR(match))
+ return PTR_ERR(match);
+
+ return component_master_add_with_match(dev, &vs_drm_ops, match);
+}
+
+static int vs_drm_platform_remove(struct platform_device *pdev)
+{
+ component_master_del(&pdev->dev, &vs_drm_ops);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int vs_drm_suspend(struct device *dev)
+{
+ return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
+}
+
+static int vs_drm_resume(struct device *dev)
+{
+ drm_mode_config_helper_resume(dev_get_drvdata(dev));
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(vs_drm_pm_ops, vs_drm_suspend, vs_drm_resume);
+
+static const struct of_device_id vs_drm_dt_ids[] = {
+ { .compatible = "starfive,display-subsystem", },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, vs_drm_dt_ids);
+
+static struct platform_driver vs_drm_platform_driver = {
+ .probe = vs_drm_platform_probe,
+ .remove = vs_drm_platform_remove,
+
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = vs_drm_dt_ids,
+ .pm = &vs_drm_pm_ops,
+ },
+};
+
+static int __init vs_drm_init(void)
+{
+ int ret;
+
+ ret = platform_register_drivers(drm_sub_drivers, ARRAY_SIZE(drm_sub_drivers));
+ if (ret)
+ return ret;
+
+ ret = drm_platform_driver_register(&vs_drm_platform_driver);
+ if (ret)
+ platform_unregister_drivers(drm_sub_drivers, ARRAY_SIZE(drm_sub_drivers));

You can probably squash all the drivers into a single array.

+
+ return ret;
+}
+
+static void __exit vs_drm_fini(void)
+{
+ platform_driver_unregister(&vs_drm_platform_driver);
+ platform_unregister_drivers(drm_sub_drivers, ARRAY_SIZE(drm_sub_drivers));
+}
+
+module_init(vs_drm_init);
+module_exit(vs_drm_fini);
+
+MODULE_DESCRIPTION("VeriSilicon DRM Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/verisilicon/vs_drv.h b/drivers/gpu/drm/verisilicon/vs_drv.h
new file mode 100644
index 000000000..369ad22d6
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/vs_drv.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
+ */
+
+#ifndef __VS_DRV_H__
+#define __VS_DRV_H__
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_managed.h>
+
+/*@pitch_alignment: buffer pitch alignment required by sub-devices.*/
+struct vs_drm_device {
+ struct drm_device base;
+ unsigned int pitch_alignment;
+};
+
+static inline struct vs_drm_device *
+to_vs_drm_private(const struct drm_device *dev)
+{
+ return container_of(dev, struct vs_drm_device, base);
+}
+
+#endif /* __VS_DRV_H__ */
diff --git a/drivers/gpu/drm/verisilicon/vs_modeset.c b/drivers/gpu/drm/verisilicon/vs_modeset.c
new file mode 100644
index 000000000..151272067
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/vs_modeset.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
+ */
+
+#include <linux/module.h>
+
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+
+#include "vs_modeset.h"
+
+static const struct drm_mode_config_funcs vs_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static struct drm_mode_config_helper_funcs vs_mode_config_helpers = {
+ .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+void vs_mode_config_init(struct drm_device *dev)
+{
+ drm_mode_config_init(dev);

quoting docs:

* FIXME: This function is deprecated and drivers should be converted over to
* drmm_mode_config_init().

+ dev->mode_config.fb_modifiers_not_supported = false;

This is the default, if I'm not mistaken

+
+ dev->mode_config.min_width = 0;
+ dev->mode_config.min_height = 0;
+ dev->mode_config.max_width = 4096;
+ dev->mode_config.max_height = 4096;
+
+ dev->mode_config.funcs = &vs_mode_config_funcs;
+ dev->mode_config.helper_private = &vs_mode_config_helpers;
+}
diff --git a/drivers/gpu/drm/verisilicon/vs_modeset.h b/drivers/gpu/drm/verisilicon/vs_modeset.h
new file mode 100644
index 000000000..ebfe6d612
--- /dev/null
+++ b/drivers/gpu/drm/verisilicon/vs_modeset.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
+ */
+
+#ifndef __VS_FB_H__
+#define __VS_FB_H__

Please match guarding define and the header name.

+
+void vs_mode_config_init(struct drm_device *dev);
+#endif /* __VS_FB_H__ */
diff --git a/include/uapi/drm/vs_drm.h b/include/uapi/drm/vs_drm.h
new file mode 100644
index 000000000..96b7fc95d
--- /dev/null
+++ b/include/uapi/drm/vs_drm.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
+ */
+
+#ifndef __VS_DRM_H__
+#define __VS_DRM_H__
+
+#include "drm.h"

Which drm.h?

+
+enum drm_vs_degamma_mode {
+ VS_DEGAMMA_DISABLE = 0,
+ VS_DEGAMMA_BT709 = 1,
+ VS_DEGAMMA_BT2020 = 2,
+};
+
+enum drm_vs_sync_dc_mode {
+ VS_SINGLE_DC = 0,
+ VS_MULTI_DC_PRIMARY = 1,
+ VS_MULTI_DC_SECONDARY = 2,
+};
+
+enum drm_vs_mmu_prefetch_mode {
+ VS_MMU_PREFETCH_DISABLE = 0,
+ VS_MMU_PREFETCH_ENABLE = 1,
+};
+
+struct drm_vs_watermark {
+ __u32 watermark;
+ __u8 qos_low;
+ __u8 qos_high;
+};
+
+struct drm_vs_color_mgmt {
+ __u32 colorkey;
+ __u32 colorkey_high;
+ __u32 clear_value;
+ bool clear_enable;
+ bool transparency;
+};
+
+struct drm_vs_roi {
+ bool enable;
+ __u16 roi_x;
+ __u16 roi_y;
+ __u16 roi_w;
+ __u16 roi_h;
+};

Could you please add corresponding defines in the patch that actually makes use of them? Otherwise it might be hard to review usage.

+
+#endif /* __VS_DRM_H__ */

--
With best wishes
Dmitry