Re: [PATCH v3 2/2] drm: verisilicon: add support for cursor planes
From: Icenowy Zheng
Date: Tue May 19 2026 - 05:09:17 EST
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@xxxxxxxxxxx>
>
> Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
>
> 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@xxxxxxxxxxx>
> > + */
> > +
> > +#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@xxxxxxxxxx>
> > + *
> > + * 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_ */