Re: [PATCH v4 8/8] media: stm32-dma2d: STM32 DMA2D driver

[Dillon Min <dillon.minfei@gmail.com>]

Hi Hans

On Thu, 14 Oct 2021 at 18:45, Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote:
>
> On 14/10/2021 12:25, dillon.minfei@gmail.com wrote:
> > From: Dillon Min <dillon.minfei@gmail.com>
> >
> > This V4L2 subdev m2m driver enables Chrom-Art Accelerator unit
> > of STMicroelectronics STM32 SoC series.
> >
> > Currently support r2m, m2m, m2m_pfc functions.
> > - r2m, Filling a part or the whole of a destination image with a specific
> >   color.
> > - m2m, Copying a part or the whole of a source image into a part or the
> >   whole of a destination.
> > - m2m_pfc, Copying a part or the whole of a source image into a part or the
> >   whole of a destination image with a pixel format conversion.
>
> While looking at the kernel log in the cover letter I noticed that the
> driver spammed the log when userspace gave incorrect values. Don't do that,
> only output kernel messages for unexpected situations.
>

Ok, these logs are useless for user space. Only useful for debugging,
I will remove these logs
in v5. it fixes the v4l2-compliance logs issue. I had to direct the
output to /dev/ttyprintk to make it show normal, in the previous test.

Thanks

> See my comments below:
>
> >
> > Signed-off-by: Dillon Min <dillon.minfei@gmail.com>
> > ---
> > v4:
> > - replace V4L2_COLORFX_SET_ARGB, V4L2_CID_COLORFX_ARGB to
> >   V4L2_COLORFX_SET_RGB, V4L2_CID_COLORFX_RGB since Alpha paramter not used
> >   in current. thanks Hans.
> >
> >  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 | 113 ++++
> >  drivers/media/platform/stm32/dma2d/dma2d.c      | 748 ++++++++++++++++++++++++
> >  drivers/media/platform/stm32/dma2d/dma2d.h      | 135 +++++
> >  7 files changed, 1151 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..4df18623e4ad 100644
> > --- a/drivers/media/platform/Kconfig
> > +++ b/drivers/media/platform/Kconfig
> > @@ -473,6 +473,15 @@ config VIDEO_STI_DELTA_DRIVER
> >
> >  endif # VIDEO_STI_DELTA
> >
> > +config VIDEO_STM32_DMA2D
> > +     tristate "STM32 Chrom-Art Accelerator (DMA2D)"
> > +     depends on (VIDEO_DEV && VIDEO_V4L2 && ARCH_STM32) || COMPILE_TEST
> > +     select VIDEOBUF2_DMA_CONTIG
> > +     select V4L2_MEM2MEM_DEV
> > +     help
> > +       The STM32 DMA2D is a memory-to-memory engine for pixel conversion
> > +       and specialized DMA dedicated to image manipulation.
> > +
> >  config VIDEO_RENESAS_FDP1
> >       tristate "Renesas Fine Display Processor"
> >       depends on VIDEO_DEV && VIDEO_V4L2
> > diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> > index 73ce083c2fc6..46f1c05bc576 100644
> > --- a/drivers/media/platform/Makefile
> > +++ b/drivers/media/platform/Makefile
> > @@ -70,6 +70,7 @@ obj-$(CONFIG_VIDEO_ATMEL_ISI)               += atmel/
> >  obj-$(CONFIG_VIDEO_ATMEL_XISC)               += 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..8c1c664ab13b
> > --- /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@gmail.com>
> > + *
> > + * based on s5p-g2d
> > + *
> > + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> > + * Kamil Debski, <k.debski@samsung.com>
> > + */
> > +
> > +#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_offset & 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_offset);
> > +
> > +     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_offset);
> > +
> > +     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..2128364406c8
> > --- /dev/null
> > +++ b/drivers/media/platform/stm32/dma2d/dma2d-regs.h
> > @@ -0,0 +1,113 @@
> > +/* 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@gmail.com>
> > + *
> > + * based on s5p-g2d
> > + *
> > + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> > + * Kamil Debski, <k.debski@samsung.com>
> > + */
> > +
> > +#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..7cef00133686
> > --- /dev/null
> > +++ b/drivers/media/platform/stm32/dma2d/dma2d.c
> > @@ -0,0 +1,748 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * STM32 DMA2D - 2D Graphics Accelerator Driver
> > + *
> > + * Copyright (c) 2021 Dillon Min
> > + * Dillon Min, <dillon.minfei@gmail.com>
> > + *
> > + * based on s5p-g2d
> > + *
> > + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> > + * Kamil Debski, <k.debski@samsung.com>
> > + */
> > +
> > +#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"
> > +
> > +/*
> > + * This V4L2 subdev m2m driver enables Chrom-Art Accelerator unit
> > + * of STMicroelectronics STM32 SoC series.
> > + *
> > + * Currently support r2m, m2m, m2m_pfc.
> > + *
> > + * - r2m, Filling a part or the whole of a destination image with a specific
> > + *   color.
> > + * - m2m, Copying a part or the whole of a source image into a part or the
> > + *   whole of a destination.
> > + * - m2m_pfc, Copying a part or the whole of a source image into a part or the
> > + *   whole of a destination image with a pixel format conversion.
> > + */
> > +
> > +#define fh2ctx(__fh) container_of(__fh, struct dma2d_ctx, fh)
> > +
> > +static const struct dma2d_fmt formats[] = {
> > +     {
> > +             .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 const struct dma2d_frame def_frame = {
> > +     .width          = DEFAULT_WIDTH,
> > +     .height         = DEFAULT_HEIGHT,
> > +     .line_offset    = 0,
> > +     .a_rgb          = {0x00, 0x00, 0x00, 0xff},
> > +     .a_mode         = DMA2D_ALPHA_MODE_NO_MODIF,
> > +     .fmt            = (struct dma2d_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 (struct dma2d_fmt *)&formats[i];
> > +     }
> > +
> > +     return NULL;
> > +}
> > +
> > +static struct dma2d_frame *get_frame(struct dma2d_ctx *ctx,
> > +                                  enum v4l2_buf_type type)
> > +{
> > +     return V4L2_TYPE_IS_OUTPUT(type) ? &ctx->cap : &ctx->out;
> > +}
> > +
> > +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 (*nplanes)
> > +             return sizes[0] < f->size ? -EINVAL : 0;
> > +
> > +     sizes[0] = f->size;
> > +     *nplanes = 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 (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);
> > +
> > +     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);
> > +}
> > +
> > +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_COLORFX:
> > +             if (ctrl->val == V4L2_COLORFX_SET_RGB)
> > +                     ctx->op_mode = DMA2D_MODE_R2M;
> > +             else if (ctrl->val == V4L2_COLORFX_NONE)
> > +                     ctx->op_mode = DMA2D_MODE_M2M;
> > +             break;
> > +     case V4L2_CID_COLORFX_RGB:
> > +             frm = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> > +             frm->a_rgb[2] = (ctrl->val >> 16) & 0xff;
> > +             frm->a_rgb[1] = (ctrl->val >> 8) & 0xff;
> > +             frm->a_rgb[0] = (ctrl->val >> 0) & 0xff;
> > +             break;
> > +     default:
> > +             v4l2_err(&ctx->dev->v4l2_dev, "Invalid control\n");
>
> Drop this line. It's already indicated by EINVAL.
>
> Never spam the kernel log on faulty userspace inputs. That's why things like
> EINVAL, EBUSY, etc. were invented :-)
>
> > +             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 int dma2d_setup_ctrls(struct dma2d_ctx *ctx)
> > +{
> > +     struct v4l2_ctrl_handler *handler = &ctx->ctrl_handler;
> > +
> > +     v4l2_ctrl_handler_init(handler, 2);
> > +
> > +     v4l2_ctrl_new_std_menu(handler, &dma2d_ctrl_ops, V4L2_CID_COLORFX,
> > +                            V4L2_COLORFX_SET_RGB, ~0x10001,
> > +                            V4L2_COLORFX_NONE);
> > +
> > +     v4l2_ctrl_new_std(handler, &dma2d_ctrl_ops, V4L2_CID_COLORFX_RGB, 0,
> > +                       0xffffff, 1, 0);
> > +
> > +     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->cap                = def_frame;
> > +     ctx->bg         = def_frame;
> > +     ctx->out        = def_frame;
> > +     ctx->op_mode    = DMA2D_MODE_M2M_FPC;
> > +     ctx->colorspace = V4L2_COLORSPACE_REC709;
> > +     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);
> > +
> > +     mutex_lock(&dev->mutex);
> > +     v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
> > +     mutex_unlock(&dev->mutex);
> > +     v4l2_ctrl_handler_free(&ctx->ctrl_handler);
> > +     v4l2_fh_del(&ctx->fh);
> > +     v4l2_fh_exit(&ctx->fh);
> > +     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);
> > +     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: %x%x%x%x, use the default.\n",
> > +                       (fourcc & 0xff),  (fourcc >>  8) & 0xff,
> > +                       (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff);
>
> Either drop this warning, or change it to v4l2_dbg. It's perfectly valid for userspace
> to pass a unsupported format, so don't spam the kernel log.
>
> > +             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);
>
> Just drop this, it's already indicated by the EBUSY error.
>
> > +             return -EBUSY;
> > +     }
> > +
> > +     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 = get_frame(ctx, f->type);
> > +     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_offset = 0;
> > +
> > +     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 || !src)
> > +             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;
> > +     u32 s = dma2d_get_int(dev);
> > +
> > +     dma2d_clear_int(dev);
> > +     if (s & ISR_TCIF || s == 0) {
> > +             clk_disable(dev->gate);
> > +
> > +             WARN_ON(!ctx);
> > +
> > +             src = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> > +             dst = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> > +
> > +             WARN_ON(!dst);
> > +             WARN_ON(!src);
> > +
> > +             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;
> > +     }
> > +
> > +     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;
> > +     vfd->lock = &dev->mutex;
> > +     vfd->v4l2_dev = &dev->v4l2_dev;
> > +     vfd->device_caps = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
> > +
> > +     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 rel_vdev;
> > +     }
> > +
> > +     ret = video_register_device(vfd, VFL_TYPE_VIDEO, 0);
> > +     if (ret) {
> > +             v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
> > +             goto free_m2m;
> > +     }
> > +
> > +     video_set_drvdata(vfd, dev);
> > +     dev->vfd = vfd;
> > +     v4l2_info(&dev->v4l2_dev, "device registered as /dev/video%d\n",
> > +               vfd->num);
> > +     return 0;
> > +
> > +free_m2m:
> > +     v4l2_m2m_release(dev->m2m_dev);
> > +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@gmail.com>");
> > +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..3f03a7ca9ee3
> > --- /dev/null
> > +++ b/drivers/media/platform/stm32/dma2d/dma2d.h
> > @@ -0,0 +1,135 @@
> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > +/*
> > + * ST stm32 DMA2D - 2D Graphics Accelerator Driver
> > + *
> > + * Copyright (c) 2021 Dillon Min
> > + * Dillon Min, <dillon.minfei@gmail.com>
> > + *
> > + * based on s5p-g2d
> > + *
> > + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> > + * Kamil Debski, <k.debski@samsung.com>
> > + */
> > +
> > +#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_offset;
> > +     /* 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      cap;
> > +     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;
> > +     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;
> > +     /* for device open/close etc */
> > +     struct mutex            mutex;
> > +     /* to avoid the conflict with device running and user setting
> > +      * at the same time
> > +      */
> > +     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