Re: [PATCH v3 2/2] drm: verisilicon: add support for cursor planes

[Icenowy Zheng <uwu@icenowy.me>]

在 2026-05-07四的 08:07 +0200，Thomas Zimmermann写道：
> Hi
> 
> Am 06.05.26 um 19:56 schrieb Icenowy Zheng:
> > Verisilicon display controllers support hardware cursors per output
> > port.
> > 
> > Add support for them as cursor planes.
> > 
> > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
> 
> You should get commit access to drm-misc, if you haven't already.
> 
> https://drm.pages.freedesktop.org/maintainer-tools/committer/commit-access.html

I raised a request at [1].

It looks like the auto labelling/assigning in the template doesn't work
(they just disappeared after submitting the issue).

[1] https://gitlab.freedesktop.org/drm/misc/kernel/-/work_items/88

Thanks,
Icenowy

> 
> Best regards
> Thomas
> 
> > ---
> > Changes in v3:
> > - Moved the validity check for max_cursor_size to
> >    vs_cursor_plane_init().
> > - Removed NULL check for new_plane_state->fb because
> >    drm_atomic_helper_check_plane_state() will set visibility to
> > false in
> >    such case.
> > Changes in v2:
> > - Use is_power_of_two instead of switch to validate cursor size.
> > - Remove unneeded format check.
> > - Skip the whole validity check if the plane is invisible
> > (previously
> >    it's only skipped when the plane is not bound to CRTC).
> > - Explicitly set modifiers list (linear only).
> > 
> >   drivers/gpu/drm/verisilicon/Makefile          |   3 +-
> >   drivers/gpu/drm/verisilicon/vs_crtc.c         |  11 +-
> >   drivers/gpu/drm/verisilicon/vs_cursor_plane.c | 272
> > ++++++++++++++++++
> >   .../drm/verisilicon/vs_cursor_plane_regs.h    |  44 +++
> >   drivers/gpu/drm/verisilicon/vs_plane.h        |   1 +
> >   5 files changed, 328 insertions(+), 3 deletions(-)
> >   create mode 100644 drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> >   create mode 100644
> > drivers/gpu/drm/verisilicon/vs_cursor_plane_regs.h
> > 
> > diff --git a/drivers/gpu/drm/verisilicon/Makefile
> > b/drivers/gpu/drm/verisilicon/Makefile
> > index fd8d805fbcde1..426f4bcaa834d 100644
> > --- a/drivers/gpu/drm/verisilicon/Makefile
> > +++ b/drivers/gpu/drm/verisilicon/Makefile
> > @@ -1,5 +1,6 @@
> >   # SPDX-License-Identifier: GPL-2.0-only
> >   
> > -verisilicon-dc-objs := vs_bridge.o vs_crtc.o vs_dc.o vs_drm.o
> > vs_hwdb.o vs_plane.o vs_primary_plane.o
> > +verisilicon-dc-objs := vs_bridge.o vs_crtc.o vs_dc.o vs_drm.o
> > vs_hwdb.o \
> > +	vs_plane.o vs_primary_plane.o vs_cursor_plane.o
> >   
> >   obj-$(CONFIG_DRM_VERISILICON_DC) += verisilicon-dc.o
> > diff --git a/drivers/gpu/drm/verisilicon/vs_crtc.c
> > b/drivers/gpu/drm/verisilicon/vs_crtc.c
> > index f494017130006..5c9714a3e69a7 100644
> > --- a/drivers/gpu/drm/verisilicon/vs_crtc.c
> > +++ b/drivers/gpu/drm/verisilicon/vs_crtc.c
> > @@ -159,7 +159,7 @@ struct vs_crtc *vs_crtc_init(struct drm_device
> > *drm_dev, struct vs_dc *dc,
> >   			     unsigned int output)
> >   {
> >   	struct vs_crtc *vcrtc;
> > -	struct drm_plane *primary;
> > +	struct drm_plane *primary, *cursor;
> >   	int ret;
> >   
> >   	vcrtc = drmm_kzalloc(drm_dev, sizeof(*vcrtc), GFP_KERNEL);
> > @@ -175,9 +175,16 @@ struct vs_crtc *vs_crtc_init(struct drm_device
> > *drm_dev, struct vs_dc *dc,
> >   		return ERR_PTR(PTR_ERR(primary));
> >   	}
> >   
> > +	/* Create our cursor plane */
> > +	cursor = vs_cursor_plane_init(drm_dev, dc);
> > +	if (IS_ERR(cursor)) {
> > +		drm_err(drm_dev, "Couldn't create the cursor
> > plane\n");
> > +		return ERR_CAST(cursor);
> > +	}
> > +
> >   	ret = drmm_crtc_init_with_planes(drm_dev, &vcrtc->base,
> >   					 primary,
> > -					 NULL,
> > +					 cursor,
> >   					 &vs_crtc_funcs,
> >   					 NULL);
> >   	if (ret) {
> > diff --git a/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> > b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> > new file mode 100644
> > index 0000000000000..acb9854fa67ed
> > --- /dev/null
> > +++ b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> > @@ -0,0 +1,272 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2026 Institute of Software, Chinese Academy of
> > Sciences (ISCAS)
> > + *
> > + * Authors:
> > + * Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > + */
> > +
> > +#include <linux/log2.h>
> > +#include <linux/regmap.h>
> > +
> > +#include <drm/drm_atomic.h>
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_crtc.h>
> > +#include <drm/drm_fourcc.h>
> > +#include <drm/drm_framebuffer.h>
> > +#include <drm/drm_gem_atomic_helper.h>
> > +#include <drm/drm_modeset_helper_vtables.h>
> > +#include <drm/drm_plane.h>
> > +#include <drm/drm_print.h>
> > +
> > +#include "vs_crtc.h"
> > +#include "vs_plane.h"
> > +#include "vs_dc.h"
> > +#include "vs_hwdb.h"
> > +#include "vs_cursor_plane_regs.h"
> > +
> > +#define VSDC_MIN_CURSOR_SIZE 32
> > +#define VSDC_MAX_CURSOR_SIZE 256
> > +
> > +#define VSDC_CURSOR_LOCATION_MAX_POSITIVE BIT_MASK(15)
> > +#define VSDC_CURSOR_LOCATION_MAX_NEGATIVE BIT_MASK(5)
> > +
> > +static bool vs_cursor_plane_check_coord(int32_t coord)
> > +{
> > +	if (coord >= 0)
> > +		return coord <= VSDC_CURSOR_LOCATION_MAX_POSITIVE;
> > +	else
> > +		return (-coord) <=
> > VSDC_CURSOR_LOCATION_MAX_NEGATIVE;
> > +}
> > +
> > +static int vs_cursor_plane_atomic_check(struct drm_plane *plane,
> > +					struct drm_atomic_state
> > *state)
> > +{
> > +	struct drm_plane_state *new_plane_state =
> > drm_atomic_get_new_plane_state(state,
> > +								
> > 		 plane);
> > +	struct drm_crtc *crtc = new_plane_state->crtc;
> > +	struct drm_framebuffer *fb = new_plane_state->fb;
> > +	struct drm_crtc_state *crtc_state = NULL;
> > +	struct vs_crtc *vcrtc;
> > +	struct vs_dc *dc;
> > +	int ret;
> > +
> > +	if (crtc)
> > +		crtc_state = drm_atomic_get_new_crtc_state(state,
> > crtc);
> > +
> > +	ret = drm_atomic_helper_check_plane_state(new_plane_state,
> > +						  crtc_state,
> > +						 
> > DRM_PLANE_NO_SCALING,
> > +						 
> > DRM_PLANE_NO_SCALING,
> > +						  true, true);
> > +	if (ret)
> > +		return ret;
> > +
> > +	if (!new_plane_state->visible)
> > +		return 0; /* Skip validity check */
> > +
> > +	vcrtc = drm_crtc_to_vs_crtc(crtc);
> > +	dc = vcrtc->dc;
> > +
> > +	/* Only certain PoT square sizes is supported. */
> > +	if (!is_power_of_2(new_plane_state->crtc_w) ||
> > +	    new_plane_state->crtc_w < VSDC_MIN_CURSOR_SIZE ||
> > +	    new_plane_state->crtc_w > dc-
> > >identity.max_cursor_size)
> > +		return -EINVAL;
> > +
> > +	if (new_plane_state->crtc_w != new_plane_state->crtc_h)
> > +		return -EINVAL;
> > +
> > +	/* Check if the cursor is inside the register fields'
> > range */
> > +	if (!vs_cursor_plane_check_coord(new_plane_state->crtc_x)
> > ||
> > +	    !vs_cursor_plane_check_coord(new_plane_state->crtc_y))
> > +		return -EINVAL;
> > +
> > +	/* Extra line padding isn't supported */
> > +	if (fb->pitches[0] !=
> > +	    drm_format_info_min_pitch(fb->format, 0,
> > new_plane_state->crtc_w))
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> > +static void vs_cursor_plane_commit(struct vs_dc *dc, unsigned int
> > output)
> > +{
> > +	regmap_set_bits(dc->regs, VSDC_CURSOR_CONFIG(output),
> > +			VSDC_CURSOR_CONFIG_COMMIT |
> > +			VSDC_CURSOR_CONFIG_IMG_UPDATE);
> > +}
> > +
> > +static void vs_cursor_plane_atomic_enable(struct drm_plane *plane,
> > +					   struct drm_atomic_state
> > *atomic_state)
> > +{
> > +	struct drm_plane_state *state =
> > drm_atomic_get_new_plane_state(atomic_state,
> > +								  
> >      plane);
> > +	struct drm_crtc *crtc = state->crtc;
> > +	struct vs_crtc *vcrtc = drm_crtc_to_vs_crtc(crtc);
> > +	unsigned int output = vcrtc->id;
> > +	struct vs_dc *dc = vcrtc->dc;
> > +
> > +	regmap_update_bits(dc->regs, VSDC_CURSOR_CONFIG(output),
> > +			   VSDC_CURSOR_CONFIG_FMT_MASK,
> > +			   VSDC_CURSOR_CONFIG_FMT_ARGB8888);
> > +
> > +	vs_cursor_plane_commit(dc, output);
> > +}
> > +
> > +static void vs_cursor_plane_atomic_disable(struct drm_plane
> > *plane,
> > +					    struct
> > drm_atomic_state *atomic_state)
> > +{
> > +	struct drm_plane_state *state =
> > drm_atomic_get_old_plane_state(atomic_state,
> > +								  
> >      plane);
> > +	struct drm_crtc *crtc = state->crtc;
> > +	struct vs_crtc *vcrtc = drm_crtc_to_vs_crtc(crtc);
> > +	unsigned int output = vcrtc->id;
> > +	struct vs_dc *dc = vcrtc->dc;
> > +
> > +	regmap_update_bits(dc->regs, VSDC_CURSOR_CONFIG(output),
> > +			   VSDC_CURSOR_CONFIG_FMT_MASK,
> > +			   VSDC_CURSOR_CONFIG_FMT_OFF);
> > +
> > +	vs_cursor_plane_commit(dc, output);
> > +}
> > +
> > +static void vs_cursor_plane_atomic_update(struct drm_plane *plane,
> > +					   struct drm_atomic_state
> > *atomic_state)
> > +{
> > +	struct drm_plane_state *state =
> > drm_atomic_get_new_plane_state(atomic_state,
> > +								  
> >      plane);
> > +	struct drm_framebuffer *fb = state->fb;
> > +	struct drm_crtc *crtc = state->crtc;
> > +	struct vs_dc *dc;
> > +	struct vs_crtc *vcrtc;
> > +	unsigned int output;
> > +	dma_addr_t dma_addr;
> > +
> > +	if (!state->visible) {
> > +		vs_cursor_plane_atomic_disable(plane,
> > atomic_state);
> > +		return;
> > +	}
> > +
> > +	vcrtc = drm_crtc_to_vs_crtc(crtc);
> > +	output = vcrtc->id;
> > +	dc = vcrtc->dc;
> > +
> > +	/* Other sizes should be rejected by atomic_check */
> > +	switch (state->crtc_w) {
> > +	case 32:
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_SIZE_MASK,
> > +				   VSDC_CURSOR_CONFIG_SIZE_32);
> > +		break;
> > +	case 64:
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_SIZE_MASK,
> > +				   VSDC_CURSOR_CONFIG_SIZE_64);
> > +		break;
> > +	case 128:
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_SIZE_MASK,
> > +				   VSDC_CURSOR_CONFIG_SIZE_128);
> > +		break;
> > +	case 256:
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_SIZE_MASK,
> > +				   VSDC_CURSOR_CONFIG_SIZE_256);
> > +		break;
> > +	}
> > +
> > +	dma_addr = vs_fb_get_dma_addr(fb, &state->src);
> > +
> > +	regmap_write(dc->regs, VSDC_CURSOR_ADDRESS(output),
> > +		     lower_32_bits(dma_addr));
> > +
> > +	/*
> > +	 * The X_OFF and Y_OFF fields define which point does the
> > LOCATION
> > +	 * register represent in the cursor image, and LOCATION
> > register
> > +	 * values are unsigned. To for positive left-top 
> > coordinates the
> > +	 * offset is set to 0 and the location is set to the
> > coordinate, for
> > +	 * negative coordinates the location is set to 0 and the
> > offset
> > +	 * is set to the opposite number of the coordinate to
> > offset the
> > +	 * cursor image partly off-screen.
> > +	 */
> > +	if (state->crtc_x >= 0) {
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_X_OFF_MASK,
> > 0);
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_LOCATION(output),
> > +				   VSDC_CURSOR_LOCATION_X_MASK,
> > +				   VSDC_CURSOR_LOCATION_X(state-
> > >crtc_x));
> > +	} else {
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_X_OFF_MASK,
> > +				   -state->crtc_x);
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_LOCATION(output),
> > +				   VSDC_CURSOR_LOCATION_X_MASK,
> > 0);
> > +	}
> > +
> > +	if (state->crtc_y >= 0) {
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_Y_OFF_MASK,
> > 0);
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_LOCATION(output),
> > +				   VSDC_CURSOR_LOCATION_Y_MASK,
> > +				   VSDC_CURSOR_LOCATION_Y(state-
> > >crtc_y));
> > +	} else {
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_CONFIG(output),
> > +				   VSDC_CURSOR_CONFIG_Y_OFF_MASK,
> > +				   -state->crtc_y);
> > +		regmap_update_bits(dc->regs,
> > VSDC_CURSOR_LOCATION(output),
> > +				   VSDC_CURSOR_LOCATION_Y_MASK,
> > 0);
> > +	}
> > +
> > +	vs_cursor_plane_commit(dc, output);
> > +}
> > +
> > +static const struct drm_plane_helper_funcs
> > vs_cursor_plane_helper_funcs = {
> > +	.atomic_check	= vs_cursor_plane_atomic_check,
> > +	.atomic_update	= vs_cursor_plane_atomic_update,
> > +	.atomic_enable	= vs_cursor_plane_atomic_enable,
> > +	.atomic_disable	= vs_cursor_plane_atomic_disable,
> > +};
> > +
> > +static const struct drm_plane_funcs vs_cursor_plane_funcs = {
> > +	.atomic_destroy_state	=
> > drm_atomic_helper_plane_destroy_state,
> > +	.atomic_duplicate_state	=
> > drm_atomic_helper_plane_duplicate_state,
> > +	.disable_plane		= drm_atomic_helper_disable_plane,
> > +	.reset			= drm_atomic_helper_plane_reset,
> > +	.update_plane		= drm_atomic_helper_update_plane,
> > +};
> > +
> > +static const u32 vs_cursor_plane_formats[] = {
> > +	DRM_FORMAT_ARGB8888,
> > +};
> > +
> > +static const u64 vs_cursor_plane_modifiers[] = {
> > +	DRM_FORMAT_MOD_LINEAR,
> > +	DRM_FORMAT_MOD_INVALID, /* sentinel */
> > +};
> > +
> > +struct drm_plane *vs_cursor_plane_init(struct drm_device *drm_dev,
> > +				       struct vs_dc *dc)
> > +{
> > +	int32_t max_cursor_size = dc->identity.max_cursor_size;
> > +	struct drm_plane *plane;
> > +
> > +	if (drm_WARN_ON_ONCE(drm_dev, max_cursor_size <
> > VSDC_MIN_CURSOR_SIZE ||
> > +				      max_cursor_size >
> > VSDC_MAX_CURSOR_SIZE))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	plane = drmm_universal_plane_alloc(drm_dev, struct
> > drm_plane, dev, 0,
> > +					   &vs_cursor_plane_funcs,
> > +					  
> > vs_cursor_plane_formats,
> > +					  
> > ARRAY_SIZE(vs_cursor_plane_formats),
> > +					  
> > vs_cursor_plane_modifiers,
> > +					   DRM_PLANE_TYPE_CURSOR,
> > +					   NULL);
> > +
> > +	if (IS_ERR(plane))
> > +		return plane;
> > +
> > +	drm_plane_helper_add(plane,
> > &vs_cursor_plane_helper_funcs);
> > +
> > +	return plane;
> > +}
> > diff --git a/drivers/gpu/drm/verisilicon/vs_cursor_plane_regs.h
> > b/drivers/gpu/drm/verisilicon/vs_cursor_plane_regs.h
> > new file mode 100644
> > index 0000000000000..99693f2c95b94
> > --- /dev/null
> > +++ b/drivers/gpu/drm/verisilicon/vs_cursor_plane_regs.h
> > @@ -0,0 +1,44 @@
> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > +/*
> > + * Copyright (C) 2025 Icenowy Zheng <uwu@icenowy.me>
> > + *
> > + * Based on vs_dc_hw.h, which is:
> > + *   Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> > + */
> > +
> > +#ifndef _VS_CURSOR_PLANE_REGS_H_
> > +#define _VS_CURSOR_PLANE_REGS_H_
> > +
> > +#include <linux/bits.h>
> > +
> > +#define VSDC_CURSOR_CONFIG(n)		(0x1468 + 0x1080 * (n))
> > +#define VSDC_CURSOR_CONFIG_FMT_MASK	GENMASK(1, 0)
> > +#define VSDC_CURSOR_CONFIG_FMT_ARGB8888	(0x2 << 0)
> > +#define VSDC_CURSOR_CONFIG_FMT_OFF	(0x0 << 0)
> > +#define VSDC_CURSOR_CONFIG_IMG_UPDATE	BIT(2)
> > +#define VSDC_CURSOR_CONFIG_COMMIT	BIT(3)
> > +#define VSDC_CURSOR_CONFIG_SIZE_MASK	GENMASK(7, 5)
> > +#define VSDC_CURSOR_CONFIG_SIZE_32	(0x0 << 5)
> > +#define VSDC_CURSOR_CONFIG_SIZE_64	(0x1 << 5)
> > +#define VSDC_CURSOR_CONFIG_SIZE_128	(0x2 << 5)
> > +#define VSDC_CURSOR_CONFIG_SIZE_256	(0x3 << 5)
> > +#define VSDC_CURSOR_CONFIG_Y_OFF_MASK	GENMASK(12, 8)
> > +#define VSDC_CURSOR_CONFIG_Y_OFF(v)	((v) << 8)
> > +#define VSDC_CURSOR_CONFIG_X_OFF_MASK	GENMASK(20, 16)
> > +#define VSDC_CURSOR_CONFIG_X_OFF(v)	((v) << 16)
> > +
> > +#define VSDC_CURSOR_ADDRESS(n)		(0x146C + 0x1080 * (n))
> > +
> > +#define VSDC_CURSOR_LOCATION(n)		(0x1470 + 0x1080 *
> > (n))
> > +#define VSDC_CURSOR_LOCATION_X_MASK	GENMASK(14, 0)
> > +#define VSDC_CURSOR_LOCATION_X(v)	((v) << 0)
> > +#define VSDC_CURSOR_LOCATION_Y_MASK	GENMASK(30, 16)
> > +#define VSDC_CURSOR_LOCATION_Y(v)	((v) << 16)
> > +
> > +#define VSDC_CURSOR_BACKGROUND(n)	(0x1474 + 0x1080 * (n))
> > +#define VSDC_CURSOR_BACKGRUOND_DEFAULT	0x00FFFFFF
> > +
> > +#define VSDC_CURSOR_FOREGROUND(n)	(0x1478 + 0x1080 * (n))
> > +#define VSDC_CURSOR_FOREGRUOND_DEFAULT	0x00AAAAAA
> > +
> > +#endif /* _VS_CURSOR_PLANE_REGS_H_ */
> > diff --git a/drivers/gpu/drm/verisilicon/vs_plane.h
> > b/drivers/gpu/drm/verisilicon/vs_plane.h
> > index 41875ea3d66a5..60b5b3a1bc22a 100644
> > --- a/drivers/gpu/drm/verisilicon/vs_plane.h
> > +++ b/drivers/gpu/drm/verisilicon/vs_plane.h
> > @@ -68,5 +68,6 @@ dma_addr_t vs_fb_get_dma_addr(struct
> > drm_framebuffer *fb,
> >   			      const struct drm_rect *src_rect);
> >   
> >   struct drm_plane *vs_primary_plane_init(struct drm_device *dev,
> > struct vs_dc *dc);
> > +struct drm_plane *vs_cursor_plane_init(struct drm_device *dev,
> > struct vs_dc *dc);
> >   
> >   #endif /* _VS_PLANE_H_ */