Re: [PATCH 7/7] media: stm32-dma2d: STM32 DMA2D driver

From: Hans Verkuil
Date: Thu Jun 17 2021 - 06:18:48 EST


Hi Dillon,

Please run checkpatch.pl --strict over this patch: I get too many 'CHECK' warnings.

On 20/05/2021 13:05, dillon.minfei@xxxxxxxxx wrote:
> From: Dillon Min <dillon.minfei@xxxxxxxxx>
>
> This V4L2 subdev m2m driver enables Chrom-Art Accelerator unit
> of STMicroelectronics STM32 SoC series.
>
> Currently support r2m, m2m, m2m_pfc.

What does this mean?

>
> Signed-off-by: Dillon Min <dillon.minfei@xxxxxxxxx>
> ---
> drivers/media/platform/Kconfig | 9 +
> drivers/media/platform/Makefile | 1 +
> drivers/media/platform/stm32/Makefile | 2 +
> drivers/media/platform/stm32/dma2d/dma2d-hw.c | 143 +++++
> drivers/media/platform/stm32/dma2d/dma2d-regs.h | 114 ++++
> drivers/media/platform/stm32/dma2d/dma2d.c | 791 ++++++++++++++++++++++++
> drivers/media/platform/stm32/dma2d/dma2d.h | 132 ++++
> 7 files changed, 1192 insertions(+)
> create mode 100644 drivers/media/platform/stm32/dma2d/dma2d-hw.c
> create mode 100644 drivers/media/platform/stm32/dma2d/dma2d-regs.h
> create mode 100644 drivers/media/platform/stm32/dma2d/dma2d.c
> create mode 100644 drivers/media/platform/stm32/dma2d/dma2d.h
>
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index 157c924686e4..128f4420623f 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -244,6 +244,15 @@ config VIDEO_CODA
> config VIDEO_IMX_VDOA
> def_tristate VIDEO_CODA if SOC_IMX6Q || COMPILE_TEST
>
> +config VIDEO_STM32_DMA2D
> + tristate "STM32 Chrom-Art Accelerator (DMA2D)"
> + depends on VIDEO_DEV && VIDEO_V4L2 && ARCH_STM32

This needs to depend on COMPILE_TEST as well.

> + select VIDEOBUF2_DMA_CONTIG
> + select V4L2_MEM2MEM_DEV
> + help
> + The STM32 DMA2D is a memory-to-memory engine for pixel conversion,
> + specialized DMA dedicated to image manipulation

Missing period at the end. And the , should probably be replaced with 'and'.

> +
> config VIDEO_IMX_PXP
> tristate "i.MX Pixel Pipeline (PXP)"
> depends on VIDEO_DEV && VIDEO_V4L2 && (ARCH_MXC || COMPILE_TEST)
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index eedc14aafb32..93b2b319a2b2 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_VIDEO_ATMEL_ISC) += atmel/
> obj-$(CONFIG_VIDEO_ATMEL_ISI) += atmel/
>
> obj-$(CONFIG_VIDEO_STM32_DCMI) += stm32/
> +obj-$(CONFIG_VIDEO_STM32_DMA2D) += stm32/
>
> obj-$(CONFIG_VIDEO_MEDIATEK_VPU) += mtk-vpu/
>
> diff --git a/drivers/media/platform/stm32/Makefile b/drivers/media/platform/stm32/Makefile
> index 48b36db2c2e2..896ef98a73ab 100644
> --- a/drivers/media/platform/stm32/Makefile
> +++ b/drivers/media/platform/stm32/Makefile
> @@ -1,2 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_VIDEO_STM32_DCMI) += stm32-dcmi.o
> +stm32-dma2d-objs := dma2d/dma2d.o dma2d/dma2d-hw.o
> +obj-$(CONFIG_VIDEO_STM32_DMA2D) += stm32-dma2d.o
> diff --git a/drivers/media/platform/stm32/dma2d/dma2d-hw.c b/drivers/media/platform/stm32/dma2d/dma2d-hw.c
> new file mode 100644
> index 000000000000..6fdbf5a21151
> --- /dev/null
> +++ b/drivers/media/platform/stm32/dma2d/dma2d-hw.c
> @@ -0,0 +1,143 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * ST stm32 Chrom-Art - 2D Graphics Accelerator Driver
> + *
> + * Copyright (c) 2021 Dillon Min
> + * Dillon Min, <dillon.minfei@xxxxxxxxx>
> + *
> + * based on s5p-g2d
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + * Kamil Debski, <k.debski@xxxxxxxxxxx>
> + */
> +
> +#include <linux/io.h>
> +
> +#include "dma2d.h"
> +#include "dma2d-regs.h"
> +
> +static inline u32 reg_read(void __iomem *base, u32 reg)
> +{
> + return readl_relaxed(base + reg);
> +}
> +
> +static inline void reg_write(void __iomem *base, u32 reg, u32 val)
> +{
> + writel_relaxed(val, base + reg);
> +}
> +
> +static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
> +{
> + reg_write(base, reg, reg_read(base, reg) | mask);
> +}
> +
> +static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
> +{
> + reg_write(base, reg, reg_read(base, reg) & ~mask);
> +}
> +
> +static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
> + u32 val)
> +{
> + reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
> +}
> +
> +void dma2d_start(struct dma2d_dev *d)
> +{
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_START, CR_START);
> +}
> +
> +u32 dma2d_get_int(struct dma2d_dev *d)
> +{
> + return reg_read(d->regs, DMA2D_ISR_REG);
> +}
> +
> +void dma2d_clear_int(struct dma2d_dev *d)
> +{
> + u32 isr_val = reg_read(d->regs, DMA2D_ISR_REG);
> +
> + reg_write(d->regs, DMA2D_IFCR_REG, isr_val & 0x003f);
> +}
> +
> +void dma2d_config_common(struct dma2d_dev *d, enum dma2d_op_mode op_mode,
> + u16 width, u16 height)
> +{
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_MODE_MASK,
> + op_mode << CR_MODE_SHIFT);
> +
> + reg_write(d->regs, DMA2D_NLR_REG, (width << 16) | height);
> +}
> +
> +void dma2d_config_out(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t o_addr)
> +{
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_CEIE, CR_CEIE);
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_CTCIE, CR_CTCIE);
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_CAEIE, CR_CAEIE);
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_TCIE, CR_TCIE);
> + reg_update_bits(d->regs, DMA2D_CR_REG, CR_TEIE, CR_TEIE);
> +
> + if (frm->fmt->cmode >= CM_MODE_ARGB8888 &&
> + frm->fmt->cmode <= CM_MODE_ARGB4444)
> + reg_update_bits(d->regs, DMA2D_OPFCCR_REG, OPFCCR_CM_MASK,
> + frm->fmt->cmode);
> +
> + reg_write(d->regs, DMA2D_OMAR_REG, o_addr);
> +
> + reg_write(d->regs, DMA2D_OCOLR_REG,
> + (frm->a_rgb[3] << 24) |
> + (frm->a_rgb[2] << 16) |
> + (frm->a_rgb[1] << 8) |
> + frm->a_rgb[0]);
> +
> + reg_update_bits(d->regs, DMA2D_OOR_REG, OOR_LO_MASK,
> + frm->line_ofs & 0x3fff);
> +}
> +
> +void dma2d_config_fg(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t f_addr)
> +{
> + reg_write(d->regs, DMA2D_FGMAR_REG, f_addr);
> + reg_update_bits(d->regs, DMA2D_FGOR_REG, FGOR_LO_MASK,
> + frm->line_ofs);
> +
> + if (frm->fmt->cmode >= CM_MODE_ARGB8888 &&
> + frm->fmt->cmode <= CM_MODE_A4)
> + reg_update_bits(d->regs, DMA2D_FGPFCCR_REG, FGPFCCR_CM_MASK,
> + frm->fmt->cmode);
> +
> + reg_update_bits(d->regs, DMA2D_FGPFCCR_REG, FGPFCCR_AM_MASK,
> + (frm->a_mode << 16) & 0x03);
> +
> + reg_update_bits(d->regs, DMA2D_FGPFCCR_REG, FGPFCCR_ALPHA_MASK,
> + frm->a_rgb[3] << 24);
> +
> + reg_write(d->regs, DMA2D_FGCOLR_REG,
> + (frm->a_rgb[2] << 16) |
> + (frm->a_rgb[1] << 8) |
> + frm->a_rgb[0]);
> +}
> +
> +void dma2d_config_bg(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t b_addr)
> +{
> + reg_write(d->regs, DMA2D_BGMAR_REG, b_addr);
> + reg_update_bits(d->regs, DMA2D_BGOR_REG, BGOR_LO_MASK,
> + frm->line_ofs);
> +
> + if (frm->fmt->cmode >= CM_MODE_ARGB8888 &&
> + frm->fmt->cmode <= CM_MODE_A4)
> + reg_update_bits(d->regs, DMA2D_BGPFCCR_REG, BGPFCCR_CM_MASK,
> + frm->fmt->cmode);
> +
> + reg_update_bits(d->regs, DMA2D_BGPFCCR_REG, BGPFCCR_AM_MASK,
> + (frm->a_mode << 16) & 0x03);
> +
> + reg_update_bits(d->regs, DMA2D_BGPFCCR_REG, BGPFCCR_ALPHA_MASK,
> + frm->a_rgb[3] << 24);
> +
> + reg_write(d->regs, DMA2D_BGCOLR_REG,
> + (frm->a_rgb[2] << 16) |
> + (frm->a_rgb[1] << 8) |
> + frm->a_rgb[0]);
> +}
> diff --git a/drivers/media/platform/stm32/dma2d/dma2d-regs.h b/drivers/media/platform/stm32/dma2d/dma2d-regs.h
> new file mode 100644
> index 000000000000..6e375bcb1281
> --- /dev/null
> +++ b/drivers/media/platform/stm32/dma2d/dma2d-regs.h
> @@ -0,0 +1,114 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * ST stm32 Chrom-Art - 2D Graphics Accelerator Driver
> + *
> + * Copyright (c) 2021 Dillon Min
> + * Dillon Min, <dillon.minfei@xxxxxxxxx>
> + *
> + * based on s5p-g2d
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + * Kamil Debski, <k.debski@xxxxxxxxxxx>
> + */
> +
> +#ifndef __DMA2D_REGS_H__
> +#define __DMA2D_REGS_H__
> +
> +#define DMA2D_CR_REG 0x0000
> +#define CR_MODE_MASK GENMASK(17, 16)
> +#define CR_MODE_SHIFT 16
> +#define CR_M2M 0x0000
> +#define CR_M2M_PFC BIT(16)
> +#define CR_M2M_BLEND BIT(17)
> +#define CR_R2M (BIT(17) | BIT(16))
> +#define CR_CEIE BIT(13)
> +#define CR_CTCIE BIT(12)
> +#define CR_CAEIE BIT(11)
> +#define CR_TWIE BIT(10)
> +#define CR_TCIE BIT(9)
> +#define CR_TEIE BIT(8)
> +#define CR_ABORT BIT(2)
> +#define CR_SUSP BIT(1)
> +#define CR_START BIT(0)
> +
> +#define DMA2D_ISR_REG 0x0004
> +#define ISR_CEIF BIT(5)
> +#define ISR_CTCIF BIT(4)
> +#define ISR_CAEIF BIT(3)
> +#define ISR_TWIF BIT(2)
> +#define ISR_TCIF BIT(1)
> +#define ISR_TEIF BIT(0)
> +
> +#define DMA2D_IFCR_REG 0x0008
> +#define IFCR_CCEIF BIT(5)
> +#define IFCR_CCTCIF BIT(4)
> +#define IFCR_CAECIF BIT(3)
> +#define IFCR_CTWIF BIT(2)
> +#define IFCR_CTCIF BIT(1)
> +#define IFCR_CTEIF BIT(0)
> +
> +#define DMA2D_FGMAR_REG 0x000c
> +#define DMA2D_FGOR_REG 0x0010
> +#define FGOR_LO_MASK GENMASK(13, 0)
> +
> +#define DMA2D_BGMAR_REG 0x0014
> +#define DMA2D_BGOR_REG 0x0018
> +#define BGOR_LO_MASK GENMASK(13, 0)
> +
> +#define DMA2D_FGPFCCR_REG 0x001c
> +#define FGPFCCR_ALPHA_MASK GENMASK(31, 24)
> +#define FGPFCCR_AM_MASK GENMASK(17, 16)
> +#define FGPFCCR_CS_MASK GENMASK(15, 8)
> +#define FGPFCCR_START BIT(5)
> +#define FGPFCCR_CCM_RGB888 BIT(4)
> +#define FGPFCCR_CM_MASK GENMASK(3, 0)
> +
> +#define DMA2D_FGCOLR_REG 0x0020
> +#define FGCOLR_REG_MASK GENMASK(23, 16)
> +#define FGCOLR_GREEN_MASK GENMASK(15, 8)
> +#define FGCOLR_BLUE_MASK GENMASK(7, 0)
> +
> +#define DMA2D_BGPFCCR_REG 0x0024
> +#define BGPFCCR_ALPHA_MASK GENMASK(31, 24)
> +#define BGPFCCR_AM_MASK GENMASK(17, 16)
> +#define BGPFCCR_CS_MASK GENMASK(15, 8)
> +#define BGPFCCR_START BIT(5)
> +#define BGPFCCR_CCM_RGB888 BIT(4)
> +#define BGPFCCR_CM_MASK GENMASK(3, 0)
> +
> +#define DMA2D_BGCOLR_REG 0x0028
> +#define BGCOLR_REG_MASK GENMASK(23, 16)
> +#define BGCOLR_GREEN_MASK GENMASK(15, 8)
> +#define BGCOLR_BLUE_MASK GENMASK(7, 0)
> +
> +#define DMA2D_OPFCCR_REG 0x0034
> +#define OPFCCR_CM_MASK GENMASK(2, 0)
> +
> +#define DMA2D_OCOLR_REG 0x0038
> +#define OCOLR_ALPHA_MASK GENMASK(31, 24)
> +#define OCOLR_RED_MASK GENMASK(23, 16)
> +#define OCOLR_GREEN_MASK GENMASK(15, 8)
> +#define OCOLR_BLUE_MASK GENMASK(7, 0)
> +
> +#define DMA2D_OMAR_REG 0x003c
> +
> +#define DMA2D_OOR_REG 0x0040
> +#define OOR_LO_MASK GENMASK(13, 0)
> +
> +#define DMA2D_NLR_REG 0x0044
> +#define NLR_PL_MASK GENMASK(29, 16)
> +#define NLR_NL_MASK GENMASK(15, 0)
> +
> +
> +/* Hardware limits */
> +#define MAX_WIDTH 0x3fff
> +#define MAX_HEIGHT 0xffff
> +
> +#define DEFAULT_WIDTH 240
> +#define DEFAULT_HEIGHT 320
> +#define DEFAULT_SIZE 307200
> +
> +#define CM_MODE_ARGB8888 0x00
> +#define CM_MODE_ARGB4444 0x04
> +#define CM_MODE_A4 0x0a
> +#endif /* __DMA2D_REGS_H__ */
> diff --git a/drivers/media/platform/stm32/dma2d/dma2d.c b/drivers/media/platform/stm32/dma2d/dma2d.c
> new file mode 100644
> index 000000000000..88f8333a174a
> --- /dev/null
> +++ b/drivers/media/platform/stm32/dma2d/dma2d.c
> @@ -0,0 +1,791 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * STM32 DMA2D - 2D Graphics Accelerator Driver
> + *
> + * Copyright (c) 2021 Dillon Min
> + * Dillon Min, <dillon.minfei@xxxxxxxxx>
> + *
> + * based on s5p-g2d
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + * Kamil Debski, <k.debski@xxxxxxxxxxx>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/fs.h>
> +#include <linux/timer.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/of.h>
> +
> +#include <linux/platform_device.h>
> +#include <media/v4l2-mem2mem.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-event.h>
> +#include <media/videobuf2-v4l2.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include "dma2d.h"
> +#include "dma2d-regs.h"
> +
> +#define fh2ctx(__fh) container_of(__fh, struct dma2d_ctx, fh)
> +
> +static struct dma2d_fmt formats[] = {

Can this be const?

> + {
> + .fourcc = V4L2_PIX_FMT_ARGB32,
> + .cmode = DMA2D_CMODE_ARGB8888,
> + .depth = 32,
> + },
> + {
> + .fourcc = V4L2_PIX_FMT_RGB24,
> + .cmode = DMA2D_CMODE_RGB888,
> + .depth = 24,
> + },
> + {
> + .fourcc = V4L2_PIX_FMT_RGB565,
> + .cmode = DMA2D_CMODE_RGB565,
> + .depth = 16,
> + },
> + {
> + .fourcc = V4L2_PIX_FMT_ARGB555,
> + .cmode = DMA2D_CMODE_ARGB1555,
> + .depth = 16,
> + },
> + {
> + .fourcc = V4L2_PIX_FMT_ARGB444,
> + .cmode = DMA2D_CMODE_ARGB4444,
> + .depth = 16,
> + },
> +};
> +#define NUM_FORMATS ARRAY_SIZE(formats)
> +
> +static struct dma2d_frame def_frame = {

Ditto.

> + .width = DEFAULT_WIDTH,
> + .height = DEFAULT_HEIGHT,
> + .line_ofs = 0,

Does 'ofs' stand for 'offset'? If so, then I prefer the full 'offset' over 'ofs'.
'ofs' is a bit obscure.

> + .a_rgb = {0x00, 0x00, 0x00, 0xff},
> + .a_mode = DMA2D_ALPHA_MODE_NO_MODIF,
> + .fmt = &formats[0],
> + .size = DEFAULT_SIZE,
> +};
> +
> +static struct dma2d_fmt *find_fmt(int pixelformat)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < NUM_FORMATS; i++) {
> + if (formats[i].fourcc == pixelformat)
> + return &formats[i];
> + }
> +
> + return NULL;
> +}
> +
> +static struct dma2d_frame *get_frame(struct dma2d_ctx *ctx,
> + enum v4l2_buf_type type)
> +{
> + switch (type) {
> + case V4L2_BUF_TYPE_VIDEO_OUTPUT:
> + return &ctx->fg;
> + case V4L2_BUF_TYPE_VIDEO_CAPTURE:
> + return &ctx->out;

Hmm, capture returns ctx->out, and output returns ctx->fg. Not exactly what
you would expect.

> + default:
> + return ERR_PTR(-EINVAL);

Using error pointers here is a bit overkill IMHO. I think returning NULL is
typical. With a WARN_ON perhaps since this really shouldn't happen.

Alternatively just do this:

return V4L2_TYPE_IS_OUTPUT(type) ? &ctx->fg : &ctx->out;

It avoids the whole problem.

> + }
> +}
> +
> +static int dma2d_queue_setup(struct vb2_queue *vq,
> + unsigned int *nbuffers, unsigned int *nplanes,
> + unsigned int sizes[], struct device *alloc_devs[])
> +{
> + struct dma2d_ctx *ctx = vb2_get_drv_priv(vq);
> + struct dma2d_frame *f = get_frame(ctx, vq->type);
> +
> + if (IS_ERR(f))
> + return PTR_ERR(f);
> +
> + if (*nplanes)
> + return sizes[0] < f->size ? -EINVAL : 0;
> +
> + sizes[0] = f->size;
> + *nplanes = 1;
> +
> + if (*nbuffers == 0)
> + *nbuffers = 1;
> +
> + return 0;
> +}
> +
> +static int dma2d_buf_out_validate(struct vb2_buffer *vb)
> +{
> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +
> + if (vbuf->field == V4L2_FIELD_ANY)
> + vbuf->field = V4L2_FIELD_NONE;
> + if (vbuf->field != V4L2_FIELD_NONE)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int dma2d_buf_prepare(struct vb2_buffer *vb)
> +{
> + struct dma2d_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
> + struct dma2d_frame *f = get_frame(ctx, vb->vb2_queue->type);
> +
> + if (IS_ERR(f))
> + return PTR_ERR(f);
> +
> + if (vb2_plane_size(vb, 0) < f->size)
> + return -EINVAL;
> +
> + vb2_set_plane_payload(vb, 0, f->size);
> +
> + return 0;
> +}
> +
> +static void dma2d_buf_queue(struct vb2_buffer *vb)
> +{
> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> + struct dma2d_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
> +
> + v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
> +}
> +
> +static int dma2d_start_streaming(struct vb2_queue *q, unsigned int count)
> +{
> + struct dma2d_ctx *ctx = vb2_get_drv_priv(q);
> + struct dma2d_frame *f = get_frame(ctx, q->type);
> +
> + if (IS_ERR(f))
> + return -EINVAL;
> +
> + f->sequence = 0;
> + return 0;
> +}
> +
> +static void dma2d_stop_streaming(struct vb2_queue *q)
> +{
> + struct dma2d_ctx *ctx = vb2_get_drv_priv(q);
> + struct vb2_v4l2_buffer *vbuf;
> +
> + for (;;) {
> + if (V4L2_TYPE_IS_OUTPUT(q->type))
> + vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> + else
> + vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> + if (!vbuf)
> + return;
> + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
> + }
> +}
> +
> +static const struct vb2_ops dma2d_qops = {
> + .queue_setup = dma2d_queue_setup,
> + .buf_out_validate = dma2d_buf_out_validate,
> + .buf_prepare = dma2d_buf_prepare,
> + .buf_queue = dma2d_buf_queue,
> + .start_streaming = dma2d_start_streaming,
> + .stop_streaming = dma2d_stop_streaming,
> + .wait_prepare = vb2_ops_wait_prepare,
> + .wait_finish = vb2_ops_wait_finish,
> +};
> +
> +static int queue_init(void *priv, struct vb2_queue *src_vq,
> + struct vb2_queue *dst_vq)
> +{
> + struct dma2d_ctx *ctx = priv;
> + int ret;
> +
> + src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
> + src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> + src_vq->drv_priv = ctx;
> + src_vq->ops = &dma2d_qops;
> + src_vq->mem_ops = &vb2_dma_contig_memops;
> + src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> + src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> + src_vq->lock = &ctx->dev->mutex;
> + src_vq->dev = ctx->dev->v4l2_dev.dev;
> +
> + ret = vb2_queue_init(src_vq);
> + if (ret)
> + return ret;
> +
> + dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> + dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> + dst_vq->drv_priv = ctx;
> + dst_vq->ops = &dma2d_qops;
> + dst_vq->mem_ops = &vb2_dma_contig_memops;
> + dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> + dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> + dst_vq->lock = &ctx->dev->mutex;
> + dst_vq->dev = ctx->dev->v4l2_dev.dev;
> +
> + return vb2_queue_init(dst_vq);
> +}
> +
> +#define V4L2_CID_DMA2D_R2M_COLOR (V4L2_CID_USER_BASE | 0x1200)
> +#define V4L2_CID_DMA2D_R2M_MODE (V4L2_CID_USER_BASE | 0x1201)

You need to reserve a range for driver-specific controls in include/uapi/linux/v4l2-controls.h.
Search for V4L2_CID_USER_CCS_BASE to see how it is done.

> +static int dma2d_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct dma2d_frame *frm;
> + struct dma2d_ctx *ctx = container_of(ctrl->handler, struct dma2d_ctx,
> + ctrl_handler);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&ctx->dev->ctrl_lock, flags);
> + switch (ctrl->id) {
> + case V4L2_CID_ALPHA_COMPONENT:
> + /* set the background alpha value*/
> + ctx->alpha_component = (u8) ctrl->val;
> + break;
> + case V4L2_CID_DMA2D_R2M_COLOR:
> + frm = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> + frm->a_rgb[3] = (ctrl->val >> 24) & 0xff;
> + frm->a_rgb[2] = (ctrl->val >> 16) & 0xff;
> + frm->a_rgb[1] = (ctrl->val >> 8) & 0xff;
> + frm->a_rgb[0] = ctrl->val & 0xff;
> + break;
> + case V4L2_CID_DMA2D_R2M_MODE:
> + if (ctrl->val)
> + ctx->op_mode = DMA2D_MODE_R2M;
> + break;
> + default:
> + v4l2_err(&ctx->dev->v4l2_dev, "Invalid control\n");
> + spin_unlock_irqrestore(&ctx->dev->ctrl_lock, flags);
> + return -EINVAL;
> +
> + }
> + spin_unlock_irqrestore(&ctx->dev->ctrl_lock, flags);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops dma2d_ctrl_ops = {
> + .s_ctrl = dma2d_s_ctrl,
> +};
> +
> +static const struct v4l2_ctrl_config dma2d_r2m_control[] = {
> + {
> + .ops = &dma2d_ctrl_ops,
> + .id = V4L2_CID_DMA2D_R2M_COLOR,
> + .name = "R2M Alpha/Color Value",
> + .type = V4L2_CTRL_TYPE_INTEGER,
> + .min = 0xffffffff80000000ULL,
> + .max = 0x7fffffff,
> + .def = 0,
> + .step = 1,
> + },
> + {
> + .ops = &dma2d_ctrl_ops,
> + .id = V4L2_CID_DMA2D_R2M_MODE,
> + .name = "Set to r2m mode",

"Set R2M Mode"

These controls need to be documented.

> + .type = V4L2_CTRL_TYPE_BOOLEAN,
> + .min = 0,
> + .max = 1,
> + .def = 0,
> + .step = 1,
> + }
> +};
> +
> +static int dma2d_setup_ctrls(struct dma2d_ctx *ctx)
> +{
> + v4l2_ctrl_handler_init(&ctx->ctrl_handler, 3);
> +
> + v4l2_ctrl_new_std(&ctx->ctrl_handler, &dma2d_ctrl_ops,
> + V4L2_CID_ALPHA_COMPONENT, 0, 255, 1, 255);
> + v4l2_ctrl_new_custom(&ctx->ctrl_handler, &dma2d_r2m_control[0], NULL);
> + v4l2_ctrl_new_custom(&ctx->ctrl_handler, &dma2d_r2m_control[1], NULL);
> +
> + return 0;
> +}
> +
> +static int dma2d_open(struct file *file)
> +{
> + struct dma2d_dev *dev = video_drvdata(file);
> + struct dma2d_ctx *ctx = NULL;
> + int ret = 0;
> +
> + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> + ctx->dev = dev;
> + /* Set default formats */
> + ctx->fg = def_frame;
> + ctx->bg = def_frame;
> + ctx->out = def_frame;
> + ctx->op_mode = DMA2D_MODE_M2M_FPC;
> + ctx->colorspace = V4L2_COLORSPACE_REC709;
> + ctx->alpha_component = 0x00;
> + if (mutex_lock_interruptible(&dev->mutex)) {
> + kfree(ctx);
> + return -ERESTARTSYS;
> + }
> +
> + ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init);
> + if (IS_ERR(ctx->fh.m2m_ctx)) {
> + ret = PTR_ERR(ctx->fh.m2m_ctx);
> + mutex_unlock(&dev->mutex);
> + kfree(ctx);
> + return ret;
> + }
> +
> + v4l2_fh_init(&ctx->fh, video_devdata(file));
> + file->private_data = &ctx->fh;
> + v4l2_fh_add(&ctx->fh);
> +
> + dma2d_setup_ctrls(ctx);
> +
> + /* Write the default values to the ctx struct */
> + v4l2_ctrl_handler_setup(&ctx->ctrl_handler);
> +
> + ctx->fh.ctrl_handler = &ctx->ctrl_handler;
> + mutex_unlock(&dev->mutex);
> +
> + return 0;
> +}
> +
> +static int dma2d_release(struct file *file)
> +{
> + struct dma2d_dev *dev = video_drvdata(file);
> + struct dma2d_ctx *ctx = fh2ctx(file->private_data);
> +
> + v4l2_ctrl_handler_free(&ctx->ctrl_handler);
> + v4l2_fh_del(&ctx->fh);
> + v4l2_fh_exit(&ctx->fh);
> + mutex_lock(&dev->mutex);
> + v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
> + mutex_unlock(&dev->mutex);
> + kfree(ctx);
> +
> + return 0;
> +}
> +
> +static int vidioc_querycap(struct file *file, void *priv,
> + struct v4l2_capability *cap)
> +{
> + strscpy(cap->driver, DMA2D_NAME, sizeof(cap->driver));
> + strscpy(cap->card, DMA2D_NAME, sizeof(cap->card));
> + strscpy(cap->bus_info, BUS_INFO, sizeof(cap->bus_info));
> +
> + return 0;
> +}
> +
> +static int vidioc_enum_fmt(struct file *file, void *prv, struct v4l2_fmtdesc *f)
> +{
> + if (f->index >= NUM_FORMATS)
> + return -EINVAL;
> +
> + f->pixelformat = formats[f->index].fourcc;
> + return 0;
> +}
> +
> +static int vidioc_g_fmt(struct file *file, void *prv, struct v4l2_format *f)
> +{
> + struct dma2d_ctx *ctx = prv;
> + struct vb2_queue *vq;
> + struct dma2d_frame *frm;
> +
> + vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
> + if (!vq)
> + return -EINVAL;
> +
> + frm = get_frame(ctx, f->type);
> + if (IS_ERR(frm))
> + return PTR_ERR(frm);
> +
> + f->fmt.pix.width = frm->width;
> + f->fmt.pix.height = frm->height;
> + f->fmt.pix.field = V4L2_FIELD_NONE;
> + f->fmt.pix.pixelformat = frm->fmt->fourcc;
> + f->fmt.pix.bytesperline = (frm->width * frm->fmt->depth) >> 3;
> + f->fmt.pix.sizeimage = frm->size;
> + f->fmt.pix.colorspace = ctx->colorspace;
> + f->fmt.pix.xfer_func = ctx->xfer_func;
> + f->fmt.pix.ycbcr_enc = ctx->ycbcr_enc;
> + f->fmt.pix.quantization = ctx->quant;
> +
> + return 0;
> +}
> +
> +static int vidioc_try_fmt(struct file *file, void *prv, struct v4l2_format *f)
> +{
> + struct dma2d_ctx *ctx = prv;
> + struct dma2d_dev *dev = ctx->dev;
> + struct dma2d_fmt *fmt;
> + enum v4l2_field *field;
> + u32 fourcc = f->fmt.pix.pixelformat;
> +
> + fmt = find_fmt(fourcc);
> + if (!fmt) {
> + v4l2_warn(&dev->v4l2_dev,
> + "Format not supported: %c%c%c%c, use the default.\n",
> + (fourcc & 0xff), (fourcc >> 8) & 0xff,
> + (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff);
> + f->fmt.pix.pixelformat = formats[0].fourcc;
> + fmt = find_fmt(f->fmt.pix.pixelformat);
> + }
> +
> + field = &f->fmt.pix.field;
> + if (*field == V4L2_FIELD_ANY)
> + *field = V4L2_FIELD_NONE;
> + else if (*field != V4L2_FIELD_NONE)
> + return -EINVAL;
> +
> + if (f->fmt.pix.width > MAX_WIDTH)
> + f->fmt.pix.width = MAX_WIDTH;
> + if (f->fmt.pix.height > MAX_HEIGHT)
> + f->fmt.pix.height = MAX_HEIGHT;
> +
> + if (f->fmt.pix.width < 1)
> + f->fmt.pix.width = 1;
> + if (f->fmt.pix.height < 1)
> + f->fmt.pix.height = 1;
> +
> + if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT && !f->fmt.pix.colorspace)
> + f->fmt.pix.colorspace = V4L2_COLORSPACE_REC709;
> + else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
> + f->fmt.pix.colorspace = ctx->colorspace;
> + f->fmt.pix.xfer_func = ctx->xfer_func;
> + f->fmt.pix.ycbcr_enc = ctx->ycbcr_enc;
> + f->fmt.pix.quantization = ctx->quant;
> + }
> + f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
> + f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
> +
> + return 0;
> +}
> +
> +static int vidioc_s_fmt(struct file *file, void *prv, struct v4l2_format *f)
> +{
> + struct dma2d_ctx *ctx = prv;
> + struct dma2d_dev *dev = ctx->dev;
> + struct vb2_queue *vq;
> + struct dma2d_frame *frm;
> + struct dma2d_fmt *fmt;
> + int ret = 0;
> +
> + /* Adjust all values accordingly to the hardware capabilities
> + * and chosen format.
> + */
> + ret = vidioc_try_fmt(file, prv, f);
> + if (ret)
> + return ret;
> +
> + vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
> + if (vb2_is_busy(vq)) {
> + v4l2_err(&dev->v4l2_dev, "queue (%d) bust\n", f->type);
> + return -EBUSY;
> + }
> +
> + frm = get_frame(ctx, f->type);
> + if (IS_ERR(frm))
> + return PTR_ERR(frm);
> +
> + fmt = find_fmt(f->fmt.pix.pixelformat);
> + if (!fmt)
> + return -EINVAL;
> +
> + if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
> + ctx->colorspace = f->fmt.pix.colorspace;
> + ctx->xfer_func = f->fmt.pix.xfer_func;
> + ctx->ycbcr_enc = f->fmt.pix.ycbcr_enc;
> + ctx->quant = f->fmt.pix.quantization;
> + }
> +
> + frm->width = f->fmt.pix.width;
> + frm->height = f->fmt.pix.height;
> + frm->size = f->fmt.pix.sizeimage;
> + /* Reset crop settings */
> + frm->o_width = 0;
> + frm->o_height = 0;
> + frm->c_width = frm->width;
> + frm->c_height = frm->height;
> + frm->right = frm->width;
> + frm->bottom = frm->height;
> + frm->fmt = fmt;
> + frm->line_ofs = 0;
> + if (f->fmt.win.global_alpha != 0) {
> + frm->a_rgb[3] = f->fmt.win.global_alpha;
> + frm->a_mode = DMA2D_ALPHA_MODE_REPLACE;
> + }
> +
> + return 0;
> +}
> +
> +static void device_run(void *prv)
> +{
> + struct dma2d_ctx *ctx = prv;
> + struct dma2d_dev *dev = ctx->dev;
> + struct dma2d_frame *frm_out, *frm_cap;
> + struct vb2_v4l2_buffer *src, *dst;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dev->ctrl_lock, flags);
> + dev->curr = ctx;
> +
> + src = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
> + dst = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
> + if (dst == NULL || src == NULL)
> + goto end;
> +
> + frm_cap = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> + frm_out = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
> + if (!frm_cap || !frm_out)
> + goto end;
> +
> + src->sequence = frm_out->sequence++;
> + dst->sequence = frm_cap->sequence++;
> + v4l2_m2m_buf_copy_metadata(src, dst, true);
> +
> + clk_enable(dev->gate);
> +
> + dma2d_config_fg(dev, frm_out,
> + vb2_dma_contig_plane_dma_addr(&src->vb2_buf, 0));
> +
> + /* TODO: add M2M_BLEND handler here */
> +
> + if (ctx->op_mode != DMA2D_MODE_R2M) {
> + if (frm_out->fmt->fourcc == frm_cap->fmt->fourcc)
> + ctx->op_mode = DMA2D_MODE_M2M;
> + else
> + ctx->op_mode = DMA2D_MODE_M2M_FPC;
> + }
> +
> + dma2d_config_out(dev, frm_cap,
> + vb2_dma_contig_plane_dma_addr(&dst->vb2_buf, 0));
> + dma2d_config_common(dev, ctx->op_mode, frm_cap->width, frm_cap->height);
> +
> + dma2d_start(dev);
> +end:
> + spin_unlock_irqrestore(&dev->ctrl_lock, flags);
> +}
> +
> +static irqreturn_t dma2d_isr(int irq, void *prv)
> +{
> + struct dma2d_dev *dev = prv;
> + struct dma2d_ctx *ctx = dev->curr;
> + struct vb2_v4l2_buffer *src, *dst;
> + uint32_t s = dma2d_get_int(dev);
> +
> + if (s & ISR_TCIF || s == 0) {
> + dma2d_clear_int(dev);
> + clk_disable(dev->gate);
> +
> + WARN_ON(ctx == NULL);
> +
> + src = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> + dst = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> +
> + WARN_ON(dst == NULL);
> + WARN_ON(src == NULL);
> +
> + v4l2_m2m_buf_done(src, VB2_BUF_STATE_DONE);
> + v4l2_m2m_buf_done(dst, VB2_BUF_STATE_DONE);
> + v4l2_m2m_job_finish(dev->m2m_dev, ctx->fh.m2m_ctx);
> +
> + dev->curr = NULL;
> + } else {
> + dma2d_clear_int(dev);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static const struct v4l2_file_operations dma2d_fops = {
> + .owner = THIS_MODULE,
> + .open = dma2d_open,
> + .release = dma2d_release,
> + .poll = v4l2_m2m_fop_poll,
> + .unlocked_ioctl = video_ioctl2,
> + .mmap = v4l2_m2m_fop_mmap,
> +#ifndef CONFIG_MMU
> + .get_unmapped_area = v4l2_m2m_get_unmapped_area,
> +#endif
> +};
> +
> +static const struct v4l2_ioctl_ops dma2d_ioctl_ops = {
> + .vidioc_querycap = vidioc_querycap,
> +
> + .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt,
> + .vidioc_g_fmt_vid_cap = vidioc_g_fmt,
> + .vidioc_try_fmt_vid_cap = vidioc_try_fmt,
> + .vidioc_s_fmt_vid_cap = vidioc_s_fmt,
> +
> + .vidioc_enum_fmt_vid_out = vidioc_enum_fmt,
> + .vidioc_g_fmt_vid_out = vidioc_g_fmt,
> + .vidioc_try_fmt_vid_out = vidioc_try_fmt,
> + .vidioc_s_fmt_vid_out = vidioc_s_fmt,
> +
> + .vidioc_reqbufs = v4l2_m2m_ioctl_reqbufs,
> + .vidioc_querybuf = v4l2_m2m_ioctl_querybuf,
> + .vidioc_qbuf = v4l2_m2m_ioctl_qbuf,
> + .vidioc_dqbuf = v4l2_m2m_ioctl_dqbuf,
> + .vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf,
> + .vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
> + .vidioc_expbuf = v4l2_m2m_ioctl_expbuf,
> +
> + .vidioc_streamon = v4l2_m2m_ioctl_streamon,
> + .vidioc_streamoff = v4l2_m2m_ioctl_streamoff,
> +
> + .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
> + .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> +};
> +
> +static const struct video_device dma2d_videodev = {
> + .name = DMA2D_NAME,
> + .fops = &dma2d_fops,
> + .ioctl_ops = &dma2d_ioctl_ops,
> + .minor = -1,
> + .release = video_device_release,
> + .vfl_dir = VFL_DIR_M2M,
> +};
> +
> +static const struct v4l2_m2m_ops dma2d_m2m_ops = {
> + .device_run = device_run,
> +};
> +
> +static const struct of_device_id stm32_dma2d_match[];
> +
> +static int dma2d_probe(struct platform_device *pdev)
> +{
> + struct dma2d_dev *dev;
> + struct video_device *vfd;
> + struct resource *res;
> + int ret = 0;
> +
> + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> + if (!dev)
> + return -ENOMEM;
> +
> + spin_lock_init(&dev->ctrl_lock);
> + mutex_init(&dev->mutex);
> + atomic_set(&dev->num_inst, 0);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + dev->regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(dev->regs))
> + return PTR_ERR(dev->regs);
> +
> + dev->gate = clk_get(&pdev->dev, "dma2d");
> + if (IS_ERR(dev->gate)) {
> + dev_err(&pdev->dev, "failed to get dma2d clock gate\n");
> + ret = -ENXIO;
> + return ret;
> + }
> +
> + ret = clk_prepare(dev->gate);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to prepare dma2d clock gate\n");
> + goto put_clk_gate;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "failed to find IRQ\n");
> + ret = -ENXIO;
> + goto unprep_clk_gate;
> + }
> +
> + dev->irq = res->start;
> +
> + ret = devm_request_irq(&pdev->dev, dev->irq, dma2d_isr,
> + 0, pdev->name, dev);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to install IRQ\n");
> + goto unprep_clk_gate;
> + }
> +
> + ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
> + if (ret)
> + goto unprep_clk_gate;
> +
> + vfd = video_device_alloc();
> + if (!vfd) {
> + v4l2_err(&dev->v4l2_dev, "Failed to allocate video device\n");
> + ret = -ENOMEM;
> + goto unreg_v4l2_dev;
> + }
> +
> + *vfd = dma2d_videodev;
> + set_bit(V4L2_FL_QUIRK_INVERTED_CROP, &vfd->flags);
> + vfd->lock = &dev->mutex;
> + vfd->v4l2_dev = &dev->v4l2_dev;
> + vfd->device_caps = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
> + ret = video_register_device(vfd, VFL_TYPE_VIDEO, 0);
> + if (ret) {
> + v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
> + goto rel_vdev;
> + }
> +
> + video_set_drvdata(vfd, dev);
> + dev->vfd = vfd;
> + v4l2_info(&dev->v4l2_dev, "device registered as /dev/video%d\n",
> + vfd->num);
> + platform_set_drvdata(pdev, dev);
> + dev->m2m_dev = v4l2_m2m_init(&dma2d_m2m_ops);
> + if (IS_ERR(dev->m2m_dev)) {
> + v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem device\n");
> + ret = PTR_ERR(dev->m2m_dev);
> + goto unreg_video_dev;
> + }
> +
> + v4l2_info(&dev->v4l2_dev, "stm32 dma2d initialized\n");
> + return 0;
> +
> +unreg_video_dev:
> + video_unregister_device(dev->vfd);
> +rel_vdev:
> + video_device_release(vfd);
> +unreg_v4l2_dev:
> + v4l2_device_unregister(&dev->v4l2_dev);
> +unprep_clk_gate:
> + clk_unprepare(dev->gate);
> +put_clk_gate:
> + clk_put(dev->gate);
> +
> + return ret;
> +}
> +
> +static int dma2d_remove(struct platform_device *pdev)
> +{
> + struct dma2d_dev *dev = platform_get_drvdata(pdev);
> +
> + v4l2_info(&dev->v4l2_dev, "Removing " DMA2D_NAME);
> + v4l2_m2m_release(dev->m2m_dev);
> + video_unregister_device(dev->vfd);
> + v4l2_device_unregister(&dev->v4l2_dev);
> + vb2_dma_contig_clear_max_seg_size(&pdev->dev);
> + clk_unprepare(dev->gate);
> + clk_put(dev->gate);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id stm32_dma2d_match[] = {
> + {
> + .compatible = "st,stm32-dma2d",
> + .data = NULL,
> + },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, stm32_dma2d_match);
> +
> +static struct platform_driver dma2d_pdrv = {
> + .probe = dma2d_probe,
> + .remove = dma2d_remove,
> + .driver = {
> + .name = DMA2D_NAME,
> + .of_match_table = stm32_dma2d_match,
> + },
> +};
> +
> +module_platform_driver(dma2d_pdrv);
> +
> +MODULE_AUTHOR("Dillon Min <dillon.minfei@xxxxxxxxx>");
> +MODULE_DESCRIPTION("STM32 Chrom-Art Accelerator DMA2D driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/media/platform/stm32/dma2d/dma2d.h b/drivers/media/platform/stm32/dma2d/dma2d.h
> new file mode 100644
> index 000000000000..1c64cd2f7587
> --- /dev/null
> +++ b/drivers/media/platform/stm32/dma2d/dma2d.h
> @@ -0,0 +1,132 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * ST stm32 DMA2D - 2D Graphics Accelerator Driver
> + *
> + * Copyright (c) 2021 Dillon Min
> + * Dillon Min, <dillon.minfei@xxxxxxxxx>
> + *
> + * based on s5p-g2d
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + * Kamil Debski, <k.debski@xxxxxxxxxxx>
> + */
> +
> +#ifndef __DMA2D_H__
> +#define __DMA2D_H__
> +
> +#include <linux/platform_device.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ctrls.h>
> +
> +#define DMA2D_NAME "stm-dma2d"
> +#define BUS_INFO "platform:stm-dma2d"
> +enum dma2d_op_mode {
> + DMA2D_MODE_M2M,
> + DMA2D_MODE_M2M_FPC,
> + DMA2D_MODE_M2M_BLEND,
> + DMA2D_MODE_R2M
> +};
> +
> +enum dma2d_cmode {
> + /* output pfc cmode from ARGB888 to ARGB4444 */
> + DMA2D_CMODE_ARGB8888,
> + DMA2D_CMODE_RGB888,
> + DMA2D_CMODE_RGB565,
> + DMA2D_CMODE_ARGB1555,
> + DMA2D_CMODE_ARGB4444,
> + /* bg or fg pfc cmode from L8 to A4 */
> + DMA2D_CMODE_L8,
> + DMA2D_CMODE_AL44,
> + DMA2D_CMODE_AL88,
> + DMA2D_CMODE_L4,
> + DMA2D_CMODE_A8,
> + DMA2D_CMODE_A4
> +};
> +
> +enum dma2d_alpha_mode {
> + DMA2D_ALPHA_MODE_NO_MODIF,
> + DMA2D_ALPHA_MODE_REPLACE,
> + DMA2D_ALPHA_MODE_COMBINE
> +};
> +
> +struct dma2d_fmt {
> + u32 fourcc;
> + int depth;
> + enum dma2d_cmode cmode;
> +};
> +
> +struct dma2d_frame {
> + /* Original dimensions */
> + u32 width;
> + u32 height;
> + /* Crop size */
> + u32 c_width;
> + u32 c_height;
> + /* Offset */
> + u32 o_width;
> + u32 o_height;
> + u32 bottom;
> + u32 right;
> + u16 line_ofs;
> + /* Image format */
> + struct dma2d_fmt *fmt;
> + /* [0]: blue
> + * [1]: green
> + * [2]: red
> + * [3]: alpha
> + */
> + u8 a_rgb[4];
> + /*
> + * AM[1:0] of DMA2D_FGPFCCR
> + */
> + enum dma2d_alpha_mode a_mode;
> + u32 size;
> + unsigned int sequence;
> +};
> +
> +struct dma2d_ctx {
> + struct v4l2_fh fh;
> + struct dma2d_dev *dev;
> + struct dma2d_frame fg;
> + struct dma2d_frame out;
> + struct dma2d_frame bg;
> + /* fb_buf always point to bg address */
> + struct v4l2_framebuffer fb_buf;
> + /*
> + * MODE[17:16] of DMA2D_CR
> + */
> + enum dma2d_op_mode op_mode;
> + u8 alpha_component;
> + struct v4l2_ctrl_handler ctrl_handler;
> + enum v4l2_colorspace colorspace;
> + enum v4l2_ycbcr_encoding ycbcr_enc;
> + enum v4l2_xfer_func xfer_func;
> + enum v4l2_quantization quant;
> +};
> +
> +struct dma2d_dev {
> + struct v4l2_device v4l2_dev;
> + struct v4l2_m2m_dev *m2m_dev;
> + struct video_device *vfd;
> + struct mutex mutex;
> + spinlock_t ctrl_lock;
> + atomic_t num_inst;
> + void __iomem *regs;
> + struct clk *gate;
> + struct dma2d_ctx *curr;
> + int irq;
> +};
> +
> +void dma2d_start(struct dma2d_dev *d);
> +u32 dma2d_get_int(struct dma2d_dev *d);
> +void dma2d_clear_int(struct dma2d_dev *d);
> +void dma2d_config_out(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t o_addr);
> +void dma2d_config_fg(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t f_addr);
> +void dma2d_config_bg(struct dma2d_dev *d, struct dma2d_frame *frm,
> + dma_addr_t b_addr);
> +void dma2d_config_common(struct dma2d_dev *d, enum dma2d_op_mode op_mode,
> + u16 width, u16 height);
> +
> +#endif /* __DMA2D_H__ */
>

Regards,

Hans