Re: [PATCH -next v2 2/2] drm: verisilicon: add support for cursor planes
From: Icenowy Zheng
Date: Tue May 05 2026 - 04:26:34 EST
在 2026-05-05二的 09:36 +0200，Thomas Zimmermann写道：
> Hi
>
> Am 24.03.26 um 07:02 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>
>
> with the comments below addressed.
>
> > ---
> > 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 | 273
> > ++++++++++++++++++
> > .../drm/verisilicon/vs_cursor_plane_regs.h | 44 +++
> > drivers/gpu/drm/verisilicon/vs_plane.h | 1 +
> > 5 files changed, 329 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..eb945462e1238
> > --- /dev/null
> > +++ b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> > @@ -0,0 +1,273 @@
> > +// 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_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, the minimum
> > supported
> > + * size is 32x32 and the maximum known size is 256x256.
> > + */
> > + drm_WARN_ON_ONCE(plane->dev, dc->identity.max_cursor_size
> > < 32 ||
> > + dc->identity.max_cursor_size
> > > 256);
>
> Rather make this drm_dbg(). User space might just run an
> atomic_check
> on an atomic_state to test if it is supported. That should not leave
> warnings in the logs.
The thing being checked is the driver's HWDB (instead of user input),
if this check fails the driver is surely buggy and misoperating.
Or maybe this check should be moved to the creating code of cursor
planes?
>
> > +
> > + if (!is_power_of_2(new_plane_state->crtc_w) ||
> > + new_plane_state->crtc_w < 32 ||
> > + 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;
> > +
> > + if (fb) {
>
> Not needed. The case of !fb would have been detected by
> drm_atomic_helper_check_plane_state(). Best regards Thomas
Yes, I checked this function and it will set visible to false (thus
here early return is triggered) when no FB is bound.
Thanks,
Icenowy
> > + /* 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)
> > +{
> > + struct drm_plane *plane;
> > +
> > + 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_ */