Re: [RFC PATCH v2 4/7] media: bcm2835-unicam: Add support for for CCP2/CSI2 camera interface

From: Laurent Pinchart
Date: Sat Jan 22 2022 - 18:28:56 EST

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In reply to: Jean-Michel Hautbois: "[RFC PATCH v2 4/7] media: bcm2835-unicam: Add support for for CCP2/CSI2 camera interface"
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Hi Jean-Michel,

Thank you for the patch.

Dave, Naush, there are a few questions for you below.

On Fri, Jan 21, 2022 at 09:18:07AM +0100, Jean-Michel Hautbois wrote:
> Add driver for the Unicam camera receiver block on BCM283x processors.
> It is represented as two video device nodes: unicam-image and
> unicam-embedded which are connected to an internal subdev (named
> unicam-subdev) in order to manage streams routing.
>
> Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> Signed-off-by: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxxxxxxxx>
>
> ---
> in v2: Remove the unicam_{info,debug,error} macros and use
> dev_dbg/dev_err instead.
> ---
> MAINTAINERS | 1 +
> drivers/media/platform/Kconfig | 1 +
> drivers/media/platform/Makefile | 2 +
> drivers/media/platform/bcm2835/Kconfig | 21 +
> drivers/media/platform/bcm2835/Makefile | 3 +
> .../media/platform/bcm2835/bcm2835-unicam.c | 2678 +++++++++++++++++
> .../media/platform/bcm2835/vc4-regs-unicam.h | 253 ++
> 7 files changed, 2959 insertions(+)
> create mode 100644 drivers/media/platform/bcm2835/Kconfig
> create mode 100644 drivers/media/platform/bcm2835/Makefile
> create mode 100644 drivers/media/platform/bcm2835/bcm2835-unicam.c
> create mode 100644 drivers/media/platform/bcm2835/vc4-regs-unicam.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 07f238fd5ff9..b17bb533e007 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3684,6 +3684,7 @@ M: Raspberry Pi Kernel Maintenance <kernel-list@xxxxxxxxxxxxxxx>
> L: linux-media@xxxxxxxxxxxxxxx
> S: Maintained
> F: Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> +F: drivers/media/platform/bcm2835/
>
> BROADCOM BCM47XX MIPS ARCHITECTURE
> M: Hauke Mehrtens <hauke@xxxxxxxxxx>
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index 9fbdba0fd1e7..033b0358fbb8 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -170,6 +170,7 @@ source "drivers/media/platform/am437x/Kconfig"
> source "drivers/media/platform/xilinx/Kconfig"
> source "drivers/media/platform/rcar-vin/Kconfig"
> source "drivers/media/platform/atmel/Kconfig"
> +source "drivers/media/platform/bcm2835/Kconfig"
> source "drivers/media/platform/sunxi/Kconfig"
>
> config VIDEO_TI_CAL
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index 19bcbced7382..689e64857db1 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -85,6 +85,8 @@ obj-$(CONFIG_VIDEO_QCOM_CAMSS) += qcom/camss/
>
> obj-$(CONFIG_VIDEO_QCOM_VENUS) += qcom/venus/
>
> +obj-y += bcm2835/

One day it would be nice to clean the media Kconfig and Makefile
infrastructure to use a consistent style for all drivers. One can always
dream :-)

> +
> obj-y += sunxi/
>
> obj-$(CONFIG_VIDEO_MESON_GE2D) += meson/ge2d/
> diff --git a/drivers/media/platform/bcm2835/Kconfig b/drivers/media/platform/bcm2835/Kconfig
> new file mode 100644
> index 000000000000..bd1370199650
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/Kconfig
> @@ -0,0 +1,21 @@
> +# Broadcom VideoCore4 V4L2 camera support
> +
> +config VIDEO_BCM2835_UNICAM
> + tristate "Broadcom BCM283x/BCM271x Unicam video capture driver"
> + depends on VIDEO_V4L2
> + depends on ARCH_BCM2835 || COMPILE_TEST

I would put the arch dependency first, but that may be just me.

> + select VIDEO_V4L2_SUBDEV_API
> + select MEDIA_CONTROLLER
> + select VIDEOBUF2_DMA_CONTIG
> + select V4L2_FWNODE

And sort there alphabetically.

> + help
> + Say Y here to enable support for the BCM283x/BCM271x CSI-2 receiver.
> + This is a V4L2 driver that controls the CSI-2 receiver directly,
> + independently from the VC4 firmware.
> + This driver is mutually exclusive with the use of bcm2835-camera. The
> + firmware will disable all access to the peripheral from within the
> + firmware if it finds a DT node using it, and bcm2835-camera will
> + therefore fail to probe.

Dave, Naush, what should we do with the bcm2835-camera driver in staging
? Do we need to keep it to support older Pi models ?

> +
> + To compile this driver as a module, choose M here. The module will be
> + called bcm2835-unicam.
> diff --git a/drivers/media/platform/bcm2835/Makefile b/drivers/media/platform/bcm2835/Makefile
> new file mode 100644
> index 000000000000..a98aba03598a
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/Makefile
> @@ -0,0 +1,3 @@
> +# Makefile for BCM2835 Unicam driver
> +
> +obj-$(CONFIG_VIDEO_BCM2835_UNICAM) += bcm2835-unicam.o
> diff --git a/drivers/media/platform/bcm2835/bcm2835-unicam.c b/drivers/media/platform/bcm2835/bcm2835-unicam.c
> new file mode 100644
> index 000000000000..7636496be00a
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
> @@ -0,0 +1,2678 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * BCM283x / BCM271x Unicam Capture Driver
> + *
> + * Copyright (C) 2017-2020 - Raspberry Pi (Trading) Ltd.
> + *
> + * Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> + *
> + * Based on TI am437x driver by
> + * Benoit Parrot <bparrot@xxxxxx>
> + * Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
> + *
> + * and TI CAL camera interface driver by
> + * Benoit Parrot <bparrot@xxxxxx>
> + *
> + *
> + * There are two camera drivers in the kernel for BCM283x - this one
> + * and bcm2835-camera (currently in staging).
> + *
> + * This driver directly controls the Unicam peripheral - there is no
> + * involvement with the VideoCore firmware. Unicam receives CSI-2 or
> + * CCP2 data and writes it into SDRAM.
> + * The only potential processing options are to repack Bayer data into an
> + * alternate format, and applying windowing.
> + * The repacking does not shift the data, so can repack V4L2_PIX_FMT_Sxxxx10P
> + * to V4L2_PIX_FMT_Sxxxx10, or V4L2_PIX_FMT_Sxxxx12P to V4L2_PIX_FMT_Sxxxx12,
> + * but not generically up to V4L2_PIX_FMT_Sxxxx16. The driver will add both
> + * formats where the relevant formats are defined, and will automatically
> + * configure the repacking as required.
> + * Support for windowing may be added later.
> + *
> + * It should be possible to connect this driver to any sensor with a
> + * suitable output interface and V4L2 subdevice driver.
> + *
> + * bcm2835-camera uses the VideoCore firmware to control the sensor,
> + * Unicam, ISP, and all tuner control loops. Fully processed frames are
> + * delivered to the driver by the firmware. It only has sensor drivers
> + * for Omnivision OV5647, and Sony IMX219 sensors.
> + *
> + * The two drivers are mutually exclusive for the same Unicam instance.
> + * The VideoCore firmware checks the device tree configuration during boot.
> + * If it finds device tree nodes called csi0 or csi1 it will block the
> + * firmware from accessing the peripheral, and bcm2835-camera will
> + * not be able to stream data.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <linux/videodev2.h>
> +
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-dev.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-dv-timings.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include <media/v4l2-async.h>
> +#define v4l2_async_nf_add_subdev __v4l2_async_nf_add_subdev

Don't do that ! It's the kind of pattern that a malicious actor would
use to obfuscate code and get vulnerabilities merged.

> +
> +#include "vc4-regs-unicam.h"
> +
> +#define UNICAM_MODULE_NAME "unicam"
> +#define UNICAM_VERSION "0.1.0"

I doubt the version would ever be incremented, so let's just drop it.

> +
> +static int debug;
> +module_param(debug, int, 0644);
> +MODULE_PARM_DESC(debug, "Debug level 0-3");

Not used.

> +
> +/*
> + * Unicam must request a minimum of 250Mhz from the VPU clock.
> + * Otherwise the input FIFOs overrun and cause image corruption.
> + */
> +#define MIN_VPU_CLOCK_RATE (250 * 1000 * 1000)
> +/*
> + * To protect against a dodgy sensor driver never returning an error from
> + * enum_mbus_code, set a maximum index value to be used.
> + */
> +#define MAX_ENUM_MBUS_CODE 128
> +
> +/*
> + * Stride is a 16 bit register, but also has to be a multiple of 32.
> + */
> +#define BPL_ALIGNMENT 32
> +#define MAX_BYTESPERLINE ((1 << 16) - BPL_ALIGNMENT)
> +/*
> + * Max width is therefore determined by the max stride divided by
> + * the number of bits per pixel. Take 32bpp as a
> + * worst case.
> + * No imposed limit on the height, so adopt a square image for want
> + * of anything better.
> + */
> +#define MAX_WIDTH (MAX_BYTESPERLINE / 4)
> +#define MAX_HEIGHT MAX_WIDTH
> +/* Define a nominal minimum image size */
> +#define MIN_WIDTH 16
> +#define MIN_HEIGHT 16
> +/* Default size of the embedded buffer */
> +#define UNICAM_EMBEDDED_SIZE 16384
> +
> +/*
> + * Size of the dummy buffer. Can be any size really, but the DMA
> + * allocation works in units of page sizes.
> + */
> +#define DUMMY_BUF_SIZE (PAGE_SIZE)

No need for parentheses.

Some of those macros have toogeneric names and may result in namespace
clashes. Please prefix them all with UNICAM_.

> +
> +#define UNICAM_SD_PAD_SINK 0
> +#define UNICAM_SD_PAD_FIRST_SOURCE 1

I'd name the source pads explicitly.

#define UNICAM_SD_PAD_SOURCE_IMAGE 1
#define UNICAM_SD_PAD_SOURCE_METADATA 2

(or META instead of METADATA, up to you, as long as we use consistent
naming through the driver).

> +#define UNICAM_SD_NUM_SOURCE_PADS 2
> +#define UNICAM_SD_NUM_PADS (1 + UNICAM_SD_NUM_SOURCE_PADS)
> +
> +static inline bool unicam_sd_pad_is_sink(u32 pad)
> +{
> + /* Camera RX has 1 sink pad, and N source pads */
> + return pad == 0;
> +}
> +
> +static inline bool unicam_sd_pad_is_source(u32 pad)
> +{
> + /* Camera RX has 1 sink pad, and N source pads */
> + return pad >= UNICAM_SD_PAD_FIRST_SOURCE &&
> + pad <= UNICAM_SD_NUM_SOURCE_PADS;

return pad != UNICAM_SD_PAD_SINK;

and drop UNICAM_SD_PAD_FIRST_SOURCE and UNICAM_SD_NUM_SOURCE_PADS.

> +}
> +
> +enum node_types {

enum unicam_node_type {

> + IMAGE_NODE,
> + METADATA_NODE,
> + MAX_NODES
> +};

UNICAM_ prefixes please.

> +
> +#define MASK_CS_DEFAULT BIT(V4L2_COLORSPACE_DEFAULT)

This and several of the macros below are not used.

> +#define MASK_CS_SMPTE170M BIT(V4L2_COLORSPACE_SMPTE170M)
> +#define MASK_CS_SMPTE240M BIT(V4L2_COLORSPACE_SMPTE240M)
> +#define MASK_CS_REC709 BIT(V4L2_COLORSPACE_REC709)
> +#define MASK_CS_BT878 BIT(V4L2_COLORSPACE_BT878)
> +#define MASK_CS_470_M BIT(V4L2_COLORSPACE_470_SYSTEM_M)
> +#define MASK_CS_470_BG BIT(V4L2_COLORSPACE_470_SYSTEM_BG)
> +#define MASK_CS_JPEG BIT(V4L2_COLORSPACE_JPEG)
> +#define MASK_CS_SRGB BIT(V4L2_COLORSPACE_SRGB)
> +#define MASK_CS_OPRGB BIT(V4L2_COLORSPACE_OPRGB)
> +#define MASK_CS_BT2020 BIT(V4L2_COLORSPACE_BT2020)
> +#define MASK_CS_RAW BIT(V4L2_COLORSPACE_RAW)
> +#define MASK_CS_DCI_P3 BIT(V4L2_COLORSPACE_DCI_P3)
> +
> +#define MAX_COLORSPACE 32
> +
> +/*
> + * struct unicam_fmt - Unicam media bus format information
> + * @pixelformat: V4L2 pixel format FCC identifier. 0 if n/a.
> + * @repacked_fourcc: V4L2 pixel format FCC identifier if the data is expanded
> + * out to 16bpp. 0 if n/a.
> + * @code: V4L2 media bus format code.
> + * @depth: Bits per pixel as delivered from the source.
> + * @csi_dt: CSI data type.
> + * @valid_colorspaces: Bitmask of valid colorspaces so that the Media Controller
> + * centric try_fmt can validate the colorspace and pass
> + * v4l2-compliance.

I'd actually drop colorspace support completely. Unicam doesn't affect
the colorspace. It will output whatever it receives from the sensor. You
can accept any colorspace on the sink pad of the subdev, and just
propagate that to the source pad.

If that causes v4l2-compliance failures, then we have a problem either
in the sensor drivers, or in v4l2-compliance.

> + * @check_variants: Flag to denote that there are multiple mediabus formats
> + * still in the list that could match this V4L2 format.
> + * @mc_skip: Media Controller shouldn't list this format via ENUM_FMT as it is
> + * a duplicate of an earlier format.
> + * @metadata_fmt: This format only applies to the metadata pad.
> + */
> +struct unicam_fmt {
> + u32 fourcc;
> + u32 repacked_fourcc;
> + u32 code;
> + u8 depth;
> + u8 csi_dt;
> + u32 valid_colorspaces;
> + u8 check_variants:1;
> + u8 mc_skip:1;
> + u8 metadata_fmt:1;
> +};
> +
> +static const struct unicam_fmt formats[] = {
> + /* YUV Formats */
> + {
> + .fourcc = V4L2_PIX_FMT_YUYV,
> + .code = MEDIA_BUS_FMT_YUYV8_2X8,

The convention for CSI-2 buses is to used the _1X16 media bus codes for
YUV. You can drop the first four entries, and drop the check_variants
and mc_skip fields.

> + .depth = 16,
> + .csi_dt = 0x1e,
> + .check_variants = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_UYVY,
> + .code = MEDIA_BUS_FMT_UYVY8_2X8,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .check_variants = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_YVYU,
> + .code = MEDIA_BUS_FMT_YVYU8_2X8,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .check_variants = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_VYUY,
> + .code = MEDIA_BUS_FMT_VYUY8_2X8,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .check_variants = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_YUYV,
> + .code = MEDIA_BUS_FMT_YUYV8_1X16,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .mc_skip = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_UYVY,
> + .code = MEDIA_BUS_FMT_UYVY8_1X16,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .mc_skip = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_YVYU,
> + .code = MEDIA_BUS_FMT_YVYU8_1X16,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .mc_skip = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + .fourcc = V4L2_PIX_FMT_VYUY,
> + .code = MEDIA_BUS_FMT_VYUY8_1X16,
> + .depth = 16,
> + .csi_dt = 0x1e,
> + .mc_skip = 1,
> + .valid_colorspaces = MASK_CS_SMPTE170M | MASK_CS_REC709 |
> + MASK_CS_JPEG,
> + }, {
> + /* RGB Formats */
> + .fourcc = V4L2_PIX_FMT_RGB565, /* gggbbbbb rrrrrggg */
> + .code = MEDIA_BUS_FMT_RGB565_2X8_LE,
> + .depth = 16,
> + .csi_dt = 0x22,
> + .valid_colorspaces = MASK_CS_SRGB,
> + }, {
> + .fourcc = V4L2_PIX_FMT_RGB565X, /* rrrrrggg gggbbbbb */
> + .code = MEDIA_BUS_FMT_RGB565_2X8_BE,
> + .depth = 16,
> + .csi_dt = 0x22,
> + .valid_colorspaces = MASK_CS_SRGB,

CSI-2 specifies the RGB565 format unambiguously, there are no little
endian of big endian variants. Let's drop one of the two entries, and
use MEDIA_BUS_FMT_RGB565_1X15. Dave, Naush, what is the correct pixel
format for this, is data layed out in big endian or little endian ?

> + }, {
> + .fourcc = V4L2_PIX_FMT_RGB555, /* gggbbbbb arrrrrgg */
> + .code = MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE,
> + .depth = 16,
> + .csi_dt = 0x21,
> + .valid_colorspaces = MASK_CS_SRGB,
> + }, {
> + .fourcc = V4L2_PIX_FMT_RGB555X, /* arrrrrgg gggbbbbb */
> + .code = MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE,
> + .depth = 16,
> + .csi_dt = 0x21,
> + .valid_colorspaces = MASK_CS_SRGB,

Same here, but we need to define a new MEDIA_BUS_FMT_RGB555_1X16 format.
The CSI-2 RGB555 data type has the padding bit between the green and
blue components, so I wonder if Unicam maps that to one of
V4L2_PIX_FMT_RGB555 or V4L2_PIX_FMT_RGB555X, or if a new pixel format is
needed too.

Another option would be to drop RGB555 support until someone needs it
(with a comment in the table to tell the entry is missing).

> + }, {
> + .fourcc = V4L2_PIX_FMT_RGB24, /* rgb */
> + .code = MEDIA_BUS_FMT_RGB888_1X24,
> + .depth = 24,
> + .csi_dt = 0x24,
> + .valid_colorspaces = MASK_CS_SRGB,
> + }, {
> + .fourcc = V4L2_PIX_FMT_BGR24, /* bgr */
> + .code = MEDIA_BUS_FMT_BGR888_1X24,
> + .depth = 24,
> + .csi_dt = 0x24,
> + .valid_colorspaces = MASK_CS_SRGB,

This is possibly more tricky, as CSI-2 defined RGB888 as being
transmitted in BGR order, but sensors could possibly also support RGB as
a non-standard extension (the same may CSI-2 standardizes on UYVY, but
many sensors can swap components). We can keep both entry I suppose.

> + }, {
> + .fourcc = V4L2_PIX_FMT_RGB32, /* argb */
> + .code = MEDIA_BUS_FMT_ARGB8888_1X32,
> + .depth = 32,
> + .csi_dt = 0x0,
> + .valid_colorspaces = MASK_CS_SRGB,

There's no 32-bit RGB in CSI-2, should this be dropped ?

> + }, {
> + /* Bayer Formats */
> + .fourcc = V4L2_PIX_FMT_SBGGR8,
> + .code = MEDIA_BUS_FMT_SBGGR8_1X8,
> + .depth = 8,
> + .csi_dt = 0x2a,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGBRG8,
> + .code = MEDIA_BUS_FMT_SGBRG8_1X8,
> + .depth = 8,
> + .csi_dt = 0x2a,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGRBG8,
> + .code = MEDIA_BUS_FMT_SGRBG8_1X8,
> + .depth = 8,
> + .csi_dt = 0x2a,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SRGGB8,
> + .code = MEDIA_BUS_FMT_SRGGB8_1X8,
> + .depth = 8,
> + .csi_dt = 0x2a,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SBGGR10P,
> + .repacked_fourcc = V4L2_PIX_FMT_SBGGR10,
> + .code = MEDIA_BUS_FMT_SBGGR10_1X10,
> + .depth = 10,
> + .csi_dt = 0x2b,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGBRG10P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGBRG10,
> + .code = MEDIA_BUS_FMT_SGBRG10_1X10,
> + .depth = 10,
> + .csi_dt = 0x2b,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGRBG10P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGRBG10,
> + .code = MEDIA_BUS_FMT_SGRBG10_1X10,
> + .depth = 10,
> + .csi_dt = 0x2b,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SRGGB10P,
> + .repacked_fourcc = V4L2_PIX_FMT_SRGGB10,
> + .code = MEDIA_BUS_FMT_SRGGB10_1X10,
> + .depth = 10,
> + .csi_dt = 0x2b,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SBGGR12P,
> + .repacked_fourcc = V4L2_PIX_FMT_SBGGR12,
> + .code = MEDIA_BUS_FMT_SBGGR12_1X12,
> + .depth = 12,
> + .csi_dt = 0x2c,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGBRG12P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGBRG12,
> + .code = MEDIA_BUS_FMT_SGBRG12_1X12,
> + .depth = 12,
> + .csi_dt = 0x2c,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGRBG12P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGRBG12,
> + .code = MEDIA_BUS_FMT_SGRBG12_1X12,
> + .depth = 12,
> + .csi_dt = 0x2c,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SRGGB12P,
> + .repacked_fourcc = V4L2_PIX_FMT_SRGGB12,
> + .code = MEDIA_BUS_FMT_SRGGB12_1X12,
> + .depth = 12,
> + .csi_dt = 0x2c,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SBGGR14P,
> + .repacked_fourcc = V4L2_PIX_FMT_SBGGR14,
> + .code = MEDIA_BUS_FMT_SBGGR14_1X14,
> + .depth = 14,
> + .csi_dt = 0x2d,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGBRG14P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGBRG14,
> + .code = MEDIA_BUS_FMT_SGBRG14_1X14,
> + .depth = 14,
> + .csi_dt = 0x2d,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SGRBG14P,
> + .repacked_fourcc = V4L2_PIX_FMT_SGRBG14,
> + .code = MEDIA_BUS_FMT_SGRBG14_1X14,
> + .depth = 14,
> + .csi_dt = 0x2d,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_SRGGB14P,
> + .repacked_fourcc = V4L2_PIX_FMT_SRGGB14,
> + .code = MEDIA_BUS_FMT_SRGGB14_1X14,
> + .depth = 14,
> + .csi_dt = 0x2d,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + /*
> + * 16 bit Bayer formats could be supported, but there is no CSI2
> + * data_type defined for raw 16, and no sensors that produce it at
> + * present.
> + */

RAW16 is now defined in CSI-2, but that can be handled later.

> +
> + /* Greyscale formats */
> + .fourcc = V4L2_PIX_FMT_GREY,
> + .code = MEDIA_BUS_FMT_Y8_1X8,
> + .depth = 8,
> + .csi_dt = 0x2a,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_Y10P,
> + .repacked_fourcc = V4L2_PIX_FMT_Y10,
> + .code = MEDIA_BUS_FMT_Y10_1X10,
> + .depth = 10,
> + .csi_dt = 0x2b,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_Y12P,
> + .repacked_fourcc = V4L2_PIX_FMT_Y12,
> + .code = MEDIA_BUS_FMT_Y12_1X12,
> + .depth = 12,
> + .csi_dt = 0x2c,
> + .valid_colorspaces = MASK_CS_RAW,
> + }, {
> + .fourcc = V4L2_PIX_FMT_Y14P,
> + .repacked_fourcc = V4L2_PIX_FMT_Y14,
> + .code = MEDIA_BUS_FMT_Y14_1X14,
> + .depth = 14,
> + .csi_dt = 0x2d,
> + .valid_colorspaces = MASK_CS_RAW,
> + },
> + /* Embedded data format */
> + {
> + .fourcc = V4L2_META_FMT_8,
> + .code = MEDIA_BUS_FMT_METADATA_8,
> + .depth = 8,
> + .metadata_fmt = 1,
> + }
> +};

Let's reorder the code a bit to improve readability:

- Macro definitions
- Structure definitions (with the container_of wrappers following the
respective structure)
- Misc helper functions (from is_metadata_node() to reg_write_field())
- Format data table and helper functions (from find_format_by_code() to
unicam_calc_format_size_bpl())
- Hardware handling:
- From unicam_wr_dma_addr() to unicam_isr()
- From unicam_set_packing_config() to unicam_disable()
- V4L2 subdev (ops & initialization & registration)
- vb2 queue opq
- V4L2 video device (ops & initialization & registration)
- Probe

I recommend adding a comment header in front of each section after the
structure definitions with a distinctive visual appearance, to delimit
code blocks very clearly. I usually use the following style:

/* -----------------------------------------------------------------------------
* V4L2 Subdev Operations
*/

> +
> +struct unicam_buffer {
> + struct vb2_v4l2_buffer vb;
> + struct list_head list;
> +};
> +
> +static inline struct unicam_buffer *to_unicam_buffer(struct vb2_buffer *vb)
> +{
> + return container_of(vb, struct unicam_buffer, vb.vb2_buf);
> +}
> +
> +struct unicam_node {
> + bool registered;
> + int open;

Not used. Please go through all structure fields and delete the ones
that are not used.

> + bool streaming;
> + unsigned int node_id;
> + /* Source pad id on the sensor for this node */
> + unsigned int src_pad_id;
> + /* Pointer pointing to current v4l2_buffer */
> + struct unicam_buffer *cur_frm;
> + /* Pointer pointing to next v4l2_buffer */
> + struct unicam_buffer *next_frm;
> + /* video capture */
> + const struct unicam_fmt *fmt;
> + /* Used to store current pixel format */
> + struct v4l2_format v_fmt;
> + /* Used to store current mbus frame format */
> + struct v4l2_mbus_framefmt m_fmt;
> + /* Buffer queue used in video-buf */
> + struct vb2_queue buffer_queue;
> + /* Queue of filled frames */
> + struct list_head dma_queue;
> + /* IRQ lock for DMA queue */
> + spinlock_t dma_queue_lock;
> + /* lock used to access this structure */
> + struct mutex lock;
> + /* Identifies video device for this channel */
> + struct video_device video_dev;
> + /* Pointer to the parent handle */
> + struct unicam_device *dev;
> + struct media_pad pad;
> + unsigned int embedded_lines;
> + struct media_pipeline pipe;
> + /*
> + * Dummy buffer intended to be used by unicam
> + * if we have no other queued buffers to swap to.
> + */
> + void *dummy_buf_cpu_addr;
> + dma_addr_t dummy_buf_dma_addr;
> +};
> +
> +struct unicam_device {
> + struct kref kref;
> +
> + /* V4l2 specific parameters */
> + struct v4l2_async_subdev asd;
> +
> + /* peripheral base address */
> + void __iomem *base;
> + /* clock gating base address */
> + void __iomem *clk_gate_base;
> + /* lp clock handle */
> + struct clk *clock;
> + /* vpu clock handle */
> + struct clk *vpu_clock;
> + /* vpu clock request */
> + struct clk_request *vpu_req;

Not used (and that may be a problem).

> + /* clock status for error handling */
> + bool clocks_enabled;
> + /* V4l2 device */
> + struct v4l2_device v4l2_dev;
> + struct media_device mdev;
> +
> + /* parent device */
> + struct platform_device *pdev;

The pdev field is only used to access pdev.dev, so I'd replace it with
the struct device.

> + /* subdevice async Notifier */
> + struct v4l2_async_notifier notifier;
> + unsigned int sequence;
> +
> + /* ptr to sub device */
> + struct v4l2_subdev *sensor;
> + /* Pad config for the sensor */
> + struct v4l2_subdev_state *sensor_state;
> +
> + /* Internal subdev */
> + struct v4l2_subdev sd;
> + struct media_pad pads[UNICAM_SD_NUM_PADS];
> +
> + bool streaming;

"streaming" is ambiguous, it's not clear it relates to the subdev. I'd
group all the fields related to the subdev in a structure:

struct {
struct v4l2_subdev sd;
struct media_pad pads[UNICAM_SD_NUM_PADS];
bool streaming;
} subdev;

(there may be more, I haven't checked)

> +
> + enum v4l2_mbus_type bus_type;
> + /*
> + * Stores bus.mipi_csi2.flags for CSI2 sensors, or
> + * bus.mipi_csi1.strobe for CCP2.
> + */
> + unsigned int bus_flags;
> + unsigned int max_data_lanes;
> + unsigned int active_data_lanes;
> + bool sensor_embedded_data;
> +
> + struct unicam_node node[MAX_NODES];
> + struct v4l2_ctrl_handler ctrl_handler;
> +
> + bool mc_api;
> +};
> +
> +static inline struct unicam_device *
> +to_unicam_device(struct v4l2_device *v4l2_dev)

I'd rename this to v4l2_device_to_unicam_device(), as there's another
container_of wrapper.

> +{
> + return container_of(v4l2_dev, struct unicam_device, v4l2_dev);
> +}
> +
> +static inline struct unicam_device *
> +sd_to_unicam_device(struct v4l2_subdev *sd)
> +{
> + return container_of(sd, struct unicam_device, sd);
> +}
> +
> +static inline bool is_metadata_node(struct unicam_node *node)
> +{
> + return node->video_dev.device_caps & V4L2_CAP_META_CAPTURE;
> +}
> +
> +static inline bool is_image_node(struct unicam_node *node)
> +{
> + return node->video_dev.device_caps & V4L2_CAP_VIDEO_CAPTURE;
> +}
> +
> +/* Hardware access */
> +static inline void clk_write(struct unicam_device *dev, u32 val)
> +{
> + writel(val | 0x5a000000, dev->clk_gate_base);
> +}

The name of this function and the functions below are too generic. Add a
unicam_ prefix.

> +
> +static inline u32 reg_read(struct unicam_device *dev, u32 offset)
> +{
> + return readl(dev->base + offset);
> +}
> +
> +static inline void reg_write(struct unicam_device *dev, u32 offset, u32 val)
> +{
> + writel(val, dev->base + offset);
> +}
> +
> +static inline int get_field(u32 value, u32 mask)
> +{
> + return (value & mask) >> __ffs(mask);
> +}
> +
> +static inline void set_field(u32 *valp, u32 field, u32 mask)
> +{
> + u32 val = *valp;
> +
> + val &= ~mask;
> + val |= (field << __ffs(mask)) & mask;
> + *valp = val;
> +}
> +
> +static inline u32 reg_read_field(struct unicam_device *dev, u32 offset,
> + u32 mask)

Not used.

> +{
> + return get_field(reg_read(dev, offset), mask);
> +}
> +
> +static inline void reg_write_field(struct unicam_device *dev, u32 offset,
> + u32 field, u32 mask)
> +{
> + u32 val = reg_read(dev, offset);
> +
> + set_field(&val, field, mask);
> + reg_write(dev, offset, val);
> +}

I'm really not a bit fan of the read-modify-update patterns, more often
than not they can be replaced by direct writes. No need to fix this
though, it's ok.

> +
> +/* Power management functions */
> +static inline int unicam_runtime_get(struct unicam_device *dev)
> +{
> + return pm_runtime_get_sync(&dev->pdev->dev);

Use pm_runtime_resume_and_get() instead, as the error handling is broken
in the driver otherwise.

> +}
> +
> +static inline void unicam_runtime_put(struct unicam_device *dev)
> +{
> + pm_runtime_put_sync(&dev->pdev->dev);
> +}

Drop these wrappers and call the functions directly.

> +
> +/* Format setup functions */
> +static const struct unicam_fmt *find_format_by_code(u32 code)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(formats); i++) {
> + if (formats[i].code == code)
> + return &formats[i];
> + }
> +
> + return NULL;
> +}
> +
> +static const struct unicam_fmt *find_format_by_fourcc(u32 fourcc)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(formats); ++i) {
> + if (formats[i].fourcc == fourcc)
> + return &formats[i];
> + }
> +
> + return NULL;
> +}
> +
> +static unsigned int bytes_per_line(u32 width, const struct unicam_fmt *fmt,
> + u32 v4l2_fourcc)
> +{
> + if (v4l2_fourcc == fmt->repacked_fourcc)
> + /* Repacking always goes to 16bpp */
> + return ALIGN(width << 1, BPL_ALIGNMENT);
> + else
> + return ALIGN((width * fmt->depth) >> 3, BPL_ALIGNMENT);
> +}
> +
> +static int unicam_calc_format_size_bpl(struct unicam_device *dev,
> + const struct unicam_fmt *fmt,
> + struct v4l2_format *f)
> +{
> + unsigned int min_bytesperline;
> +
> + v4l_bound_align_image(&f->fmt.pix.width, MIN_WIDTH, MAX_WIDTH, 2,
> + &f->fmt.pix.height, MIN_HEIGHT, MAX_HEIGHT, 0,
> + 0);
> +
> + min_bytesperline = bytes_per_line(f->fmt.pix.width, fmt,
> + f->fmt.pix.pixelformat);
> +
> + if (f->fmt.pix.bytesperline > min_bytesperline &&
> + f->fmt.pix.bytesperline <= MAX_BYTESPERLINE)
> + f->fmt.pix.bytesperline = ALIGN(f->fmt.pix.bytesperline,
> + BPL_ALIGNMENT);
> + else
> + f->fmt.pix.bytesperline = min_bytesperline;
> +
> + f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
> +
> + dev_dbg(dev->v4l2_dev.dev, "%s: fourcc: %08X size: %dx%d bpl:%d img_size:%d\n",
> + __func__,
> + f->fmt.pix.pixelformat,
> + f->fmt.pix.width, f->fmt.pix.height,
> + f->fmt.pix.bytesperline, f->fmt.pix.sizeimage);
> +
> + return 0;
> +}
> +
> +static void unicam_wr_dma_addr(struct unicam_device *dev, dma_addr_t dmaaddr,
> + unsigned int buffer_size, int node_id)
> +{
> + dma_addr_t endaddr = dmaaddr + buffer_size;
> +
> + if (node_id == IMAGE_NODE) {
> + reg_write(dev, UNICAM_IBSA0, dmaaddr);
> + reg_write(dev, UNICAM_IBEA0, endaddr);
> + } else {
> + reg_write(dev, UNICAM_DBSA0, dmaaddr);
> + reg_write(dev, UNICAM_DBEA0, endaddr);
> + }
> +}
> +
> +static unsigned int unicam_get_lines_done(struct unicam_device *dev)
> +{
> + dma_addr_t start_addr, cur_addr;
> + unsigned int stride = dev->node[IMAGE_NODE].v_fmt.fmt.pix.bytesperline;
> + struct unicam_buffer *frm = dev->node[IMAGE_NODE].cur_frm;
> +
> + if (!frm)
> + return 0;
> +
> + start_addr = vb2_dma_contig_plane_dma_addr(&frm->vb.vb2_buf, 0);
> + cur_addr = reg_read(dev, UNICAM_IBWP);
> + return (unsigned int)(cur_addr - start_addr) / stride;
> +}
> +
> +static void unicam_schedule_next_buffer(struct unicam_node *node)
> +{
> + struct unicam_device *dev = node->dev;
> + struct unicam_buffer *buf;
> + unsigned int size;
> + dma_addr_t addr;
> +
> + buf = list_first_entry(&node->dma_queue, struct unicam_buffer, list);
> + node->next_frm = buf;
> + list_del(&buf->list);
> +
> + addr = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
> + if (is_image_node(node)) {
> + size = node->v_fmt.fmt.pix.sizeimage;
> + unicam_wr_dma_addr(dev, addr, size, IMAGE_NODE);
> + } else {
> + size = node->v_fmt.fmt.meta.buffersize;
> + unicam_wr_dma_addr(dev, addr, size, METADATA_NODE);
> + }
> +}
> +
> +static void unicam_schedule_dummy_buffer(struct unicam_node *node)
> +{
> + struct unicam_device *dev = node->dev;
> + int node_id = is_image_node(node) ? IMAGE_NODE : METADATA_NODE;
> +
> + dev_dbg(dev->v4l2_dev.dev, "Scheduling dummy buffer for node %d\n", node_id);
> +
> + unicam_wr_dma_addr(dev, node->dummy_buf_dma_addr, DUMMY_BUF_SIZE,
> + node_id);
> + node->next_frm = NULL;
> +}
> +
> +static void unicam_process_buffer_complete(struct unicam_node *node,
> + unsigned int sequence)
> +{
> + node->cur_frm->vb.field = node->m_fmt.field;
> + node->cur_frm->vb.sequence = sequence;
> +
> + vb2_buffer_done(&node->cur_frm->vb.vb2_buf, VB2_BUF_STATE_DONE);
> +}
> +
> +static void unicam_queue_event_sof(struct unicam_device *unicam)
> +{
> + struct v4l2_event event = {
> + .type = V4L2_EVENT_FRAME_SYNC,
> + .u.frame_sync.frame_sequence = unicam->sequence,
> + };
> +
> + v4l2_event_queue(&unicam->node[IMAGE_NODE].video_dev, &event);
> +}
> +
> +/*
> + * unicam_isr : ISR handler for unicam capture
> + * @irq: irq number
> + * @dev_id: dev_id ptr
> + *
> + * It changes status of the captured buffer, takes next buffer from the queue
> + * and sets its address in unicam registers
> + */
> +static irqreturn_t unicam_isr(int irq, void *dev)
> +{
> + struct unicam_device *unicam = dev;
> + unsigned int lines_done = unicam_get_lines_done(dev);
> + unsigned int sequence = unicam->sequence;
> + unsigned int i;
> + u32 ista, sta;
> + bool fe;
> + u64 ts;
> +
> + sta = reg_read(unicam, UNICAM_STA);
> + /* Write value back to clear the interrupts */
> + reg_write(unicam, UNICAM_STA, sta);
> +
> + ista = reg_read(unicam, UNICAM_ISTA);
> + /* Write value back to clear the interrupts */
> + reg_write(unicam, UNICAM_ISTA, ista);
> +
> + dev_dbg(unicam->v4l2_dev.dev, "ISR: ISTA: 0x%X, STA: 0x%X, sequence %d, lines done %d",
> + ista, sta, sequence, lines_done);
> +
> + if (!(sta & (UNICAM_IS | UNICAM_PI0)))
> + return IRQ_HANDLED;
> +
> + /*
> + * Look for either the Frame End interrupt or the Packet Capture status
> + * to signal a frame end.
> + */
> + fe = (ista & UNICAM_FEI || sta & UNICAM_PI0);

No need for the outer parentheses.

> +
> + /*
> + * We must run the frame end handler first. If we have a valid next_frm
> + * and we get a simultaneout FE + FS interrupt, running the FS handler
> + * first would null out the next_frm ptr and we would have lost the
> + * buffer forever.
> + */
> + if (fe) {
> + /*
> + * Ensure we have swapped buffers already as we can't
> + * stop the peripheral. If no buffer is available, use a
> + * dummy buffer to dump out frames until we get a new buffer
> + * to use.
> + */
> + for (i = 0; i < ARRAY_SIZE(unicam->node); i++) {
> + if (!unicam->node[i].streaming)
> + continue;
> +
> + /*
> + * If cur_frm == next_frm, it means we have not had
> + * a chance to swap buffers, likely due to having
> + * multiple interrupts occurring simultaneously (like FE
> + * + FS + LS). In this case, we cannot signal the buffer
> + * as complete, as the HW will reuse that buffer.
> + */
> + if (unicam->node[i].cur_frm &&
> + unicam->node[i].cur_frm != unicam->node[i].next_frm)
> + unicam_process_buffer_complete(&unicam->node[i],
> + sequence);
> + unicam->node[i].cur_frm = unicam->node[i].next_frm;
> + }
> + unicam->sequence++;
> + }
> +
> + if (ista & UNICAM_FSI) {
> + /*
> + * Timestamp is to be when the first data byte was captured,
> + * aka frame start.
> + */
> + ts = ktime_get_ns();
> + for (i = 0; i < ARRAY_SIZE(unicam->node); i++) {
> + if (!unicam->node[i].streaming)
> + continue;
> +
> + if (unicam->node[i].cur_frm)
> + unicam->node[i].cur_frm->vb.vb2_buf.timestamp =
> + ts;
> + else
> + dev_dbg(unicam->v4l2_dev.dev, "ISR: [%d] Dropping frame, buffer not available at FS\n",
> + i);
> + /*
> + * Set the next frame output to go to a dummy frame
> + * if we have not managed to obtain another frame
> + * from the queue.
> + */
> + unicam_schedule_dummy_buffer(&unicam->node[i]);
> + }
> +
> + unicam_queue_event_sof(unicam);
> + }
> +
> + /*
> + * Cannot swap buffer at frame end, there may be a race condition
> + * where the HW does not actually swap it if the new frame has
> + * already started.
> + */
> + if (ista & (UNICAM_FSI | UNICAM_LCI) && !fe) {
> + for (i = 0; i < ARRAY_SIZE(unicam->node); i++) {
> + if (!unicam->node[i].streaming)
> + continue;
> +
> + spin_lock(&unicam->node[i].dma_queue_lock);
> + if (!list_empty(&unicam->node[i].dma_queue) &&
> + !unicam->node[i].next_frm)
> + unicam_schedule_next_buffer(&unicam->node[i]);
> + spin_unlock(&unicam->node[i].dma_queue_lock);
> + }
> + }
> +
> + if (reg_read(unicam, UNICAM_ICTL) & UNICAM_FCM) {
> + /* Switch out of trigger mode if selected */
> + reg_write_field(unicam, UNICAM_ICTL, 1, UNICAM_TFC);
> + reg_write_field(unicam, UNICAM_ICTL, 0, UNICAM_FCM);
> + }
> + return IRQ_HANDLED;
> +}
> +
> +/* V4L2 Common IOCTLs */
> +static int unicam_querycap(struct file *file, void *priv,
> + struct v4l2_capability *cap)
> +{
> + struct unicam_node *node = video_drvdata(file);
> + struct unicam_device *dev = node->dev;
> +
> + strscpy(cap->driver, UNICAM_MODULE_NAME, sizeof(cap->driver));
> + strscpy(cap->card, UNICAM_MODULE_NAME, sizeof(cap->card));
> +
> + snprintf(cap->bus_info, sizeof(cap->bus_info),
> + "platform:%s", dev_name(&dev->pdev->dev));
> +
> + cap->capabilities |= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_META_CAPTURE;
> +
> + return 0;
> +}
> +
> +static int unicam_log_status(struct file *file, void *fh)
> +{
> + struct unicam_node *node = video_drvdata(file);
> + struct unicam_device *dev = node->dev;
> + u32 reg;
> +
> + /* status for sub devices */
> + v4l2_device_call_all(&dev->v4l2_dev, 0, core, log_status);

I'm tempted to drop this, bit I won't insist.

> +
> + dev_info(dev->v4l2_dev.dev, "-----Receiver status-----\n");
> + dev_info(dev->v4l2_dev.dev, "V4L2 width/height: %ux%u\n",
> + node->v_fmt.fmt.pix.width, node->v_fmt.fmt.pix.height);
> + dev_info(dev->v4l2_dev.dev, "Mediabus format: %08x\n", node->fmt->code);
> + dev_info(dev->v4l2_dev.dev, "V4L2 format: %08x\n",
> + node->v_fmt.fmt.pix.pixelformat);
> + reg = reg_read(dev, UNICAM_IPIPE);
> + dev_info(dev->v4l2_dev.dev, "Unpacking/packing: %u / %u\n",
> + get_field(reg, UNICAM_PUM_MASK),
> + get_field(reg, UNICAM_PPM_MASK));
> + dev_info(dev->v4l2_dev.dev, "----Live data----\n");
> + dev_info(dev->v4l2_dev.dev, "Programmed stride: %4u\n",
> + reg_read(dev, UNICAM_IBLS));
> + dev_info(dev->v4l2_dev.dev, "Detected resolution: %ux%u\n",
> + reg_read(dev, UNICAM_IHSTA),
> + reg_read(dev, UNICAM_IVSTA));
> + dev_info(dev->v4l2_dev.dev, "Write pointer: %08x\n",
> + reg_read(dev, UNICAM_IBWP));
> +
> + return 0;
> +}
> +
> +static int unicam_subscribe_event(struct v4l2_fh *fh,
> + const struct v4l2_event_subscription *sub)
> +{
> + switch (sub->type) {
> + case V4L2_EVENT_FRAME_SYNC:
> + return v4l2_event_subscribe(fh, sub, 2, NULL);
> + case V4L2_EVENT_SOURCE_CHANGE:
> + return v4l2_event_subscribe(fh, sub, 4, NULL);

The drive doesn't generate V4L2_EVENT_SOURCE_CHANGE events, drop it.

> + }
> +
> + return v4l2_ctrl_subscribe_event(fh, sub);
> +}
> +
> +static void unicam_notify(struct v4l2_subdev *sd,
> + unsigned int notification, void *arg)
> +{
> + struct unicam_device *dev = to_unicam_device(sd->v4l2_dev);

Use sd_to_unicam_device().

> +
> + switch (notification) {
> + case V4L2_DEVICE_NOTIFY_EVENT:
> + v4l2_event_queue(&dev->node[IMAGE_NODE].video_dev, arg);
> + break;
> + default:
> + break;
> + }
> +}

Not needed, drop it.

> +
> +/* V4L2 Media Controller Centric IOCTLs */
> +
> +static int unicam_mc_enum_fmt_vid_cap(struct file *file, void *priv,
> + struct v4l2_fmtdesc *f)

Drop "mc" in all function names as that's the only option now.

> +{
> + int i, j;

Never negative, can be unsigned int.

j is not a loop counter but the format index, I'd rename it to index to
make it clearer.

> +
> + for (i = 0, j = 0; i < ARRAY_SIZE(formats); i++) {
> + if (f->mbus_code && formats[i].code != f->mbus_code)
> + continue;
> + if (formats[i].mc_skip || formats[i].metadata_fmt)
> + continue;
> +
> + if (formats[i].fourcc) {

All entries have a fourcc so you can drop this check.

> + if (j == f->index) {
> + f->pixelformat = formats[i].fourcc;
> + f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

Not needed, the type is an input parameter. Same below.

> + return 0;
> + }
> + j++;
> + }
> + if (formats[i].repacked_fourcc) {
> + if (j == f->index) {
> + f->pixelformat = formats[i].repacked_fourcc;
> + f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> + return 0;
> + }
> + j++;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int unicam_mc_g_fmt_vid_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> +
> + if (!is_image_node(node))
> + return -EINVAL;

Can this happen ?

> +
> + *f = node->v_fmt;
> +
> + return 0;
> +}
> +
> +static void unicam_mc_try_fmt(struct unicam_node *node, struct v4l2_format *f,
> + const struct unicam_fmt **ret_fmt)
> +{
> + struct v4l2_pix_format *v4l2_format = &f->fmt.pix;
> + struct unicam_device *dev = node->dev;
> + const struct unicam_fmt *fmt;
> + int is_rgb;

bool.

> +
> + /*
> + * Default to the first format if the requested pixel format code isn't
> + * supported.
> + */
> + fmt = find_format_by_fourcc(v4l2_format->pixelformat);
> + if (!fmt) {
> + fmt = &formats[0];
> + v4l2_format->pixelformat = fmt->fourcc;
> + }
> +
> + unicam_calc_format_size_bpl(dev, fmt, f);
> +
> + if (v4l2_format->field == V4L2_FIELD_ANY)
> + v4l2_format->field = V4L2_FIELD_NONE;
> +
> + if (v4l2_format->colorspace >= MAX_COLORSPACE ||
> + !(fmt->valid_colorspaces & (1 << v4l2_format->colorspace))) {
> + v4l2_format->colorspace = __ffs(fmt->valid_colorspaces);
> +
> + v4l2_format->xfer_func =
> + V4L2_MAP_XFER_FUNC_DEFAULT(v4l2_format->colorspace);
> + v4l2_format->ycbcr_enc =
> + V4L2_MAP_YCBCR_ENC_DEFAULT(v4l2_format->colorspace);
> + is_rgb = v4l2_format->colorspace == V4L2_COLORSPACE_SRGB;
> + v4l2_format->quantization =
> + V4L2_MAP_QUANTIZATION_DEFAULT(is_rgb,
> + v4l2_format->colorspace,
> + v4l2_format->ycbcr_enc);
> + }

Drop this, we can accept any colorspace produced by the sensor.

> +
> + if (ret_fmt)
> + *ret_fmt = fmt;

How about returning the format from the function instead ?

> +
> + dev_dbg(dev->v4l2_dev.dev, "%s: %08x %ux%u (bytesperline %u sizeimage %u)\n",
> + __func__, v4l2_format->pixelformat,
> + v4l2_format->width, v4l2_format->height,
> + v4l2_format->bytesperline, v4l2_format->sizeimage);
> +}
> +
> +static int unicam_mc_try_fmt_vid_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> +
> + unicam_mc_try_fmt(node, f, NULL);
> + return 0;
> +}
> +
> +static int unicam_mc_s_fmt_vid_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> + struct unicam_device *dev = node->dev;
> + const struct unicam_fmt *fmt;
> +
> + if (vb2_is_busy(&node->buffer_queue)) {
> + dev_dbg(dev->v4l2_dev.dev, "%s device busy\n", __func__);
> + return -EBUSY;
> + }
> +
> + unicam_mc_try_fmt(node, f, &fmt);
> +
> + node->v_fmt = *f;
> + node->fmt = fmt;
> +
> + return 0;
> +}
> +
> +static int unicam_mc_enum_framesizes(struct file *file, void *fh,
> + struct v4l2_frmsizeenum *fsize)
> +{
> + struct unicam_node *node = video_drvdata(file);
> + struct unicam_device *dev = node->dev;
> +
> + if (fsize->index > 0)
> + return -EINVAL;
> +
> + if (!find_format_by_fourcc(fsize->pixel_format)) {
> + dev_dbg(dev->v4l2_dev.dev, "Invalid pixel format 0x%08x\n",
> + fsize->pixel_format);

I'd drop this message.

> + return -EINVAL;
> + }
> +
> + fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
> + fsize->stepwise.min_width = MIN_WIDTH;
> + fsize->stepwise.max_width = MAX_WIDTH;
> + fsize->stepwise.step_width = 1;
> + fsize->stepwise.min_height = MIN_HEIGHT;
> + fsize->stepwise.max_height = MAX_HEIGHT;
> + fsize->stepwise.step_height = 1;

Is this valid for the metadata node too ?

> +
> + return 0;
> +}
> +
> +static int unicam_mc_enum_fmt_meta_cap(struct file *file, void *priv,
> + struct v4l2_fmtdesc *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> + int i, j;
> +
> + if (!is_metadata_node(node))
> + return -EINVAL;

Same comments as for video format enumeration.

> +
> + for (i = 0, j = 0; i < ARRAY_SIZE(formats); i++) {
> + if (f->mbus_code && formats[i].code != f->mbus_code)
> + continue;
> + if (!formats[i].metadata_fmt)
> + continue;
> +
> + if (formats[i].fourcc) {
> + if (j == f->index) {
> + f->pixelformat = formats[i].fourcc;
> + f->type = V4L2_BUF_TYPE_META_CAPTURE;
> + return 0;
> + }
> + j++;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int unicam_mc_g_fmt_meta_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> +
> + if (!is_metadata_node(node))
> + return -EINVAL;

Can this happen ? Same below.

> +
> + *f = node->v_fmt;
> +
> + return 0;
> +}
> +
> +static int unicam_mc_try_fmt_meta_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> +
> + if (!is_metadata_node(node))
> + return -EINVAL;
> +
> + f->fmt.meta.dataformat = V4L2_META_FMT_8;
> +
> + return 0;
> +}
> +
> +static int unicam_mc_s_fmt_meta_cap(struct file *file, void *priv,
> + struct v4l2_format *f)
> +{
> + struct unicam_node *node = video_drvdata(file);
> +
> + if (!is_metadata_node(node))
> + return -EINVAL;
> +
> + unicam_mc_try_fmt_meta_cap(file, priv, f);
> +
> + node->v_fmt = *f;
> +
> + return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops unicam_mc_ioctl_ops = {
> + .vidioc_querycap = unicam_querycap,
> + .vidioc_enum_fmt_vid_cap = unicam_mc_enum_fmt_vid_cap,
> + .vidioc_g_fmt_vid_cap = unicam_mc_g_fmt_vid_cap,
> + .vidioc_try_fmt_vid_cap = unicam_mc_try_fmt_vid_cap,
> + .vidioc_s_fmt_vid_cap = unicam_mc_s_fmt_vid_cap,
> +
> + .vidioc_enum_fmt_meta_cap = unicam_mc_enum_fmt_meta_cap,
> + .vidioc_g_fmt_meta_cap = unicam_mc_g_fmt_meta_cap,
> + .vidioc_try_fmt_meta_cap = unicam_mc_try_fmt_meta_cap,
> + .vidioc_s_fmt_meta_cap = unicam_mc_s_fmt_meta_cap,
> +
> + .vidioc_enum_framesizes = unicam_mc_enum_framesizes,
> + .vidioc_reqbufs = vb2_ioctl_reqbufs,
> + .vidioc_create_bufs = vb2_ioctl_create_bufs,
> + .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
> + .vidioc_querybuf = vb2_ioctl_querybuf,
> + .vidioc_qbuf = vb2_ioctl_qbuf,
> + .vidioc_dqbuf = vb2_ioctl_dqbuf,
> + .vidioc_expbuf = vb2_ioctl_expbuf,
> + .vidioc_streamon = vb2_ioctl_streamon,
> + .vidioc_streamoff = vb2_ioctl_streamoff,
> +
> + .vidioc_log_status = unicam_log_status,
> + .vidioc_subscribe_event = unicam_subscribe_event,
> + .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> +};
> +
> +static const struct media_entity_operations unicam_mc_entity_ops = {
> + .link_validate = v4l2_subdev_link_validate,
> + .has_route = v4l2_subdev_has_route,
> +};

I don't think this is needed for the video nodes.

> +
> +/* videobuf2 Operations */
> +
> +static int unicam_queue_setup(struct vb2_queue *vq,
> + unsigned int *nbuffers,
> + unsigned int *nplanes,
> + unsigned int sizes[],
> + struct device *alloc_devs[])
> +{
> + struct unicam_node *node = vb2_get_drv_priv(vq);
> + struct unicam_device *dev = node->dev;
> + unsigned int size = is_image_node(node) ?
> + node->v_fmt.fmt.pix.sizeimage :
> + node->v_fmt.fmt.meta.buffersize;
> +
> + if (vq->num_buffers + *nbuffers < 3)
> + *nbuffers = 3 - vq->num_buffers;
> +
> + if (*nplanes) {
> + if (sizes[0] < size) {
> + dev_err(dev->v4l2_dev.dev, "sizes[0] %i < size %u\n", sizes[0],
> + size);

This can be a debug message, let's not give a way to unprivileged
userspace to flood the kernel log.

> + return -EINVAL;
> + }
> + size = sizes[0];
> + }
> +
> + *nplanes = 1;
> + sizes[0] = size;
> +
> + return 0;
> +}
> +
> +static int unicam_buffer_prepare(struct vb2_buffer *vb)
> +{
> + struct unicam_node *node = vb2_get_drv_priv(vb->vb2_queue);
> + struct unicam_device *dev = node->dev;
> + struct unicam_buffer *buf = to_unicam_buffer(vb);
> + unsigned long size;
> +
> + if (WARN_ON(!node->fmt))
> + return -EINVAL;
> +
> + size = is_image_node(node) ? node->v_fmt.fmt.pix.sizeimage :
> + node->v_fmt.fmt.meta.buffersize;
> + if (vb2_plane_size(vb, 0) < size) {
> + dev_err(dev->v4l2_dev.dev, "data will not fit into plane (%lu < %lu)\n",
> + vb2_plane_size(vb, 0), size);

Debug message here too.

> + return -EINVAL;
> + }
> +
> + vb2_set_plane_payload(&buf->vb.vb2_buf, 0, size);
> + return 0;
> +}
> +
> +static void unicam_buffer_queue(struct vb2_buffer *vb)
> +{
> + struct unicam_node *node = vb2_get_drv_priv(vb->vb2_queue);
> + struct unicam_buffer *buf = to_unicam_buffer(vb);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&node->dma_queue_lock, flags);

Small optimization, as this is guaranteed to be called with interrupts
enabled, you can use the spin_lock_irq() variant.

> + list_add_tail(&buf->list, &node->dma_queue);
> + spin_unlock_irqrestore(&node->dma_queue_lock, flags);
> +}
> +
> +static void unicam_set_packing_config(struct unicam_device *dev)
> +{
> + u32 pack, unpack;
> + u32 val;
> +
> + if (dev->node[IMAGE_NODE].v_fmt.fmt.pix.pixelformat ==
> + dev->node[IMAGE_NODE].fmt->fourcc) {
> + unpack = UNICAM_PUM_NONE;
> + pack = UNICAM_PPM_NONE;
> + } else {
> + switch (dev->node[IMAGE_NODE].fmt->depth) {
> + case 8:
> + unpack = UNICAM_PUM_UNPACK8;
> + break;
> + case 10:
> + unpack = UNICAM_PUM_UNPACK10;
> + break;
> + case 12:
> + unpack = UNICAM_PUM_UNPACK12;
> + break;
> + case 14:
> + unpack = UNICAM_PUM_UNPACK14;
> + break;
> + case 16:
> + unpack = UNICAM_PUM_UNPACK16;
> + break;
> + default:
> + unpack = UNICAM_PUM_NONE;
> + break;
> + }
> +
> + /* Repacking is always to 16bpp */
> + pack = UNICAM_PPM_PACK16;
> + }
> +
> + val = 0;
> + set_field(&val, unpack, UNICAM_PUM_MASK);
> + set_field(&val, pack, UNICAM_PPM_MASK);
> + reg_write(dev, UNICAM_IPIPE, val);
> +}
> +
> +static void unicam_cfg_image_id(struct unicam_device *dev)
> +{
> + if (dev->bus_type == V4L2_MBUS_CSI2_DPHY) {
> + /* CSI2 mode, hardcode VC 0 for now. */
> + reg_write(dev, UNICAM_IDI0,
> + (0 << 6) | dev->node[IMAGE_NODE].fmt->csi_dt);
> + } else {
> + /* CCP2 mode */
> + reg_write(dev, UNICAM_IDI0,
> + 0x80 | dev->node[IMAGE_NODE].fmt->csi_dt);
> + }
> +}
> +
> +static void unicam_enable_ed(struct unicam_device *dev)
> +{
> + u32 val = reg_read(dev, UNICAM_DCS);
> +
> + set_field(&val, 2, UNICAM_EDL_MASK);
> + /* Do not wrap at the end of the embedded data buffer */
> + set_field(&val, 0, UNICAM_DBOB);
> +
> + reg_write(dev, UNICAM_DCS, val);
> +}
> +
> +static void unicam_start_rx(struct unicam_device *dev, dma_addr_t *addr)
> +{
> + int line_int_freq = dev->node[IMAGE_NODE].v_fmt.fmt.pix.height >> 2;
> + unsigned int size, i;
> + u32 val;
> +
> + if (line_int_freq < 128)
> + line_int_freq = 128;
> +
> + /* Enable lane clocks */
> + val = 1;
> + for (i = 0; i < dev->active_data_lanes; i++)
> + val = val << 2 | 1;
> + clk_write(dev, val);
> +
> + /* Basic init */
> + reg_write(dev, UNICAM_CTRL, UNICAM_MEM);
> +
> + /* Enable analogue control, and leave in reset. */
> + val = UNICAM_AR;
> + set_field(&val, 7, UNICAM_CTATADJ_MASK);
> + set_field(&val, 7, UNICAM_PTATADJ_MASK);
> + reg_write(dev, UNICAM_ANA, val);
> + usleep_range(1000, 2000);
> +
> + /* Come out of reset */
> + reg_write_field(dev, UNICAM_ANA, 0, UNICAM_AR);
> +
> + /* Peripheral reset */
> + reg_write_field(dev, UNICAM_CTRL, 1, UNICAM_CPR);
> + reg_write_field(dev, UNICAM_CTRL, 0, UNICAM_CPR);
> +
> + reg_write_field(dev, UNICAM_CTRL, 0, UNICAM_CPE);
> +
> + /* Enable Rx control. */
> + val = reg_read(dev, UNICAM_CTRL);
> + if (dev->bus_type == V4L2_MBUS_CSI2_DPHY) {
> + set_field(&val, UNICAM_CPM_CSI2, UNICAM_CPM_MASK);
> + set_field(&val, UNICAM_DCM_STROBE, UNICAM_DCM_MASK);
> + } else {
> + set_field(&val, UNICAM_CPM_CCP2, UNICAM_CPM_MASK);
> + set_field(&val, dev->bus_flags, UNICAM_DCM_MASK);
> + }
> + /* Packet framer timeout */
> + set_field(&val, 0xf, UNICAM_PFT_MASK);
> + set_field(&val, 128, UNICAM_OET_MASK);
> + reg_write(dev, UNICAM_CTRL, val);
> +
> + reg_write(dev, UNICAM_IHWIN, 0);
> + reg_write(dev, UNICAM_IVWIN, 0);
> +
> + /* AXI bus access QoS setup */
> + val = reg_read(dev, UNICAM_PRI);
> + set_field(&val, 0, UNICAM_BL_MASK);
> + set_field(&val, 0, UNICAM_BS_MASK);
> + set_field(&val, 0xe, UNICAM_PP_MASK);
> + set_field(&val, 8, UNICAM_NP_MASK);
> + set_field(&val, 2, UNICAM_PT_MASK);
> + set_field(&val, 1, UNICAM_PE);
> + reg_write(dev, UNICAM_PRI, val);
> +
> + reg_write_field(dev, UNICAM_ANA, 0, UNICAM_DDL);
> +
> + /* Always start in trigger frame capture mode (UNICAM_FCM set) */
> + val = UNICAM_FSIE | UNICAM_FEIE | UNICAM_FCM | UNICAM_IBOB;
> + set_field(&val, line_int_freq, UNICAM_LCIE_MASK);
> + reg_write(dev, UNICAM_ICTL, val);
> + reg_write(dev, UNICAM_STA, UNICAM_STA_MASK_ALL);
> + reg_write(dev, UNICAM_ISTA, UNICAM_ISTA_MASK_ALL);
> +
> + /* tclk_term_en */
> + reg_write_field(dev, UNICAM_CLT, 2, UNICAM_CLT1_MASK);
> + /* tclk_settle */
> + reg_write_field(dev, UNICAM_CLT, 6, UNICAM_CLT2_MASK);
> + /* td_term_en */
> + reg_write_field(dev, UNICAM_DLT, 2, UNICAM_DLT1_MASK);
> + /* ths_settle */
> + reg_write_field(dev, UNICAM_DLT, 6, UNICAM_DLT2_MASK);
> + /* trx_enable */
> + reg_write_field(dev, UNICAM_DLT, 0, UNICAM_DLT3_MASK);
> +
> + reg_write_field(dev, UNICAM_CTRL, 0, UNICAM_SOE);
> +
> + /* Packet compare setup - required to avoid missing frame ends */
> + val = 0;
> + set_field(&val, 1, UNICAM_PCE);
> + set_field(&val, 1, UNICAM_GI);
> + set_field(&val, 1, UNICAM_CPH);
> + set_field(&val, 0, UNICAM_PCVC_MASK);
> + set_field(&val, 1, UNICAM_PCDT_MASK);
> + reg_write(dev, UNICAM_CMP0, val);
> +
> + /* Enable clock lane and set up terminations */
> + val = 0;
> + if (dev->bus_type == V4L2_MBUS_CSI2_DPHY) {
> + /* CSI2 */
> + set_field(&val, 1, UNICAM_CLE);
> + set_field(&val, 1, UNICAM_CLLPE);
> + if (dev->bus_flags & V4L2_MBUS_CSI2_CONTINUOUS_CLOCK) {
> + set_field(&val, 1, UNICAM_CLTRE);
> + set_field(&val, 1, UNICAM_CLHSE);
> + }
> + } else {
> + /* CCP2 */
> + set_field(&val, 1, UNICAM_CLE);
> + set_field(&val, 1, UNICAM_CLHSE);
> + set_field(&val, 1, UNICAM_CLTRE);
> + }
> + reg_write(dev, UNICAM_CLK, val);
> +
> + /*
> + * Enable required data lanes with appropriate terminations.
> + * The same value needs to be written to UNICAM_DATn registers for
> + * the active lanes, and 0 for inactive ones.
> + */
> + val = 0;
> + if (dev->bus_type == V4L2_MBUS_CSI2_DPHY) {
> + /* CSI2 */
> + set_field(&val, 1, UNICAM_DLE);
> + set_field(&val, 1, UNICAM_DLLPE);
> + if (dev->bus_flags & V4L2_MBUS_CSI2_CONTINUOUS_CLOCK) {
> + set_field(&val, 1, UNICAM_DLTRE);
> + set_field(&val, 1, UNICAM_DLHSE);
> + }
> + } else {
> + /* CCP2 */
> + set_field(&val, 1, UNICAM_DLE);
> + set_field(&val, 1, UNICAM_DLHSE);
> + set_field(&val, 1, UNICAM_DLTRE);
> + }
> + reg_write(dev, UNICAM_DAT0, val);
> +
> + if (dev->active_data_lanes == 1)
> + val = 0;
> + reg_write(dev, UNICAM_DAT1, val);
> +
> + if (dev->max_data_lanes > 2) {
> + /*
> + * Registers UNICAM_DAT2 and UNICAM_DAT3 only valid if the
> + * instance supports more than 2 data lanes.
> + */
> + if (dev->active_data_lanes == 2)
> + val = 0;
> + reg_write(dev, UNICAM_DAT2, val);
> +
> + if (dev->active_data_lanes == 3)
> + val = 0;
> + reg_write(dev, UNICAM_DAT3, val);
> + }
> +
> + reg_write(dev, UNICAM_IBLS,
> + dev->node[IMAGE_NODE].v_fmt.fmt.pix.bytesperline);
> + size = dev->node[IMAGE_NODE].v_fmt.fmt.pix.sizeimage;
> + unicam_wr_dma_addr(dev, addr[IMAGE_NODE], size, IMAGE_NODE);
> + unicam_set_packing_config(dev);
> + unicam_cfg_image_id(dev);
> +
> + val = reg_read(dev, UNICAM_MISC);
> + set_field(&val, 1, UNICAM_FL0);
> + set_field(&val, 1, UNICAM_FL1);
> + reg_write(dev, UNICAM_MISC, val);
> +
> + if (dev->node[METADATA_NODE].streaming && dev->sensor_embedded_data) {
> + dev_dbg(dev->v4l2_dev.dev, "enable metadata dma\n");
> + size = dev->node[METADATA_NODE].v_fmt.fmt.meta.buffersize;
> + unicam_enable_ed(dev);
> + unicam_wr_dma_addr(dev, addr[METADATA_NODE], size, METADATA_NODE);
> + }
> +
> + /* Enable peripheral */
> + reg_write_field(dev, UNICAM_CTRL, 1, UNICAM_CPE);
> +
> + /* Load image pointers */
> + reg_write_field(dev, UNICAM_ICTL, 1, UNICAM_LIP_MASK);
> +
> + /* Load embedded data buffer pointers if needed */
> + if (dev->node[METADATA_NODE].streaming && dev->sensor_embedded_data)
> + reg_write_field(dev, UNICAM_DCS, 1, UNICAM_LDP);
> +
> + /*
> + * Enable trigger only for the first frame to
> + * sync correctly to the FS from the source.
> + */
> + reg_write_field(dev, UNICAM_ICTL, 1, UNICAM_TFC);
> +}
> +
> +static void unicam_disable(struct unicam_device *dev)
> +{
> + /* Analogue lane control disable */
> + reg_write_field(dev, UNICAM_ANA, 1, UNICAM_DDL);
> +
> + /* Stop the output engine */
> + reg_write_field(dev, UNICAM_CTRL, 1, UNICAM_SOE);
> +
> + /* Disable the data lanes. */
> + reg_write(dev, UNICAM_DAT0, 0);
> + reg_write(dev, UNICAM_DAT1, 0);
> +
> + if (dev->max_data_lanes > 2) {
> + reg_write(dev, UNICAM_DAT2, 0);
> + reg_write(dev, UNICAM_DAT3, 0);
> + }
> +
> + /* Peripheral reset */
> + reg_write_field(dev, UNICAM_CTRL, 1, UNICAM_CPR);
> + usleep_range(50, 100);
> + reg_write_field(dev, UNICAM_CTRL, 0, UNICAM_CPR);
> +
> + /* Disable peripheral */
> + reg_write_field(dev, UNICAM_CTRL, 0, UNICAM_CPE);
> +
> + /* Clear ED setup */
> + reg_write(dev, UNICAM_DCS, 0);
> +
> + /* Disable all lane clocks */
> + clk_write(dev, 0);
> +}
> +
> +static void unicam_return_buffers(struct unicam_node *node,
> + enum vb2_buffer_state state)
> +{
> + struct unicam_buffer *buf, *tmp;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&node->dma_queue_lock, flags);

Same here, spin_lock_irq() would do. But isn't this function meant to be
called with the hardware stopped ? Shouldn't it then be safe to drop the
spinlock completely ?

> + list_for_each_entry_safe(buf, tmp, &node->dma_queue, list) {
> + list_del(&buf->list);
> + vb2_buffer_done(&buf->vb.vb2_buf, state);
> + }
> +
> + if (node->cur_frm)
> + vb2_buffer_done(&node->cur_frm->vb.vb2_buf,
> + state);
> + if (node->next_frm && node->cur_frm != node->next_frm)
> + vb2_buffer_done(&node->next_frm->vb.vb2_buf,
> + state);
> +
> + node->cur_frm = NULL;
> + node->next_frm = NULL;
> + spin_unlock_irqrestore(&node->dma_queue_lock, flags);
> +}
> +
> +static int unicam_video_check_format(struct unicam_node *node)
> +{
> + const struct v4l2_mbus_framefmt *format;
> + struct media_pad *remote_pad;
> + struct v4l2_subdev_state *state;
> + int ret = 0;
> +
> + remote_pad = media_entity_remote_pad(&node->pad);
> + if (!remote_pad)
> + return -ENODEV;

This could be done in unicam_async_complete() and cached in the
unicam_device structure, the same way we cache the sensor subdev
pointer.

> +
> + state = v4l2_subdev_lock_active_state(node->dev->sensor);

That's not correct, the video node is connected to the subdev, not to
the sensor.

> +
> + format = v4l2_state_get_stream_format(state,
> + remote_pad->index, 0);

This holds on a single line.

> + if (!format) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + if (node->fmt->code != format->code ||
> + node->v_fmt.fmt.pix.height != format->height ||
> + node->v_fmt.fmt.pix.width != format->width ||
> + node->v_fmt.fmt.pix.field != format->field) {

A debug message that prints the configuration on both sides could be
useful for debugging here.

> + ret = -EPIPE;
> + goto out;
> + }
> +
> +out:
> + v4l2_subdev_unlock_state(state);
> +
> + return ret;
> +}
> +
> +static int unicam_start_streaming(struct vb2_queue *vq, unsigned int count)
> +{
> + struct unicam_node *node = vb2_get_drv_priv(vq);
> + struct unicam_device *dev = node->dev;
> + dma_addr_t buffer_addr[MAX_NODES] = { 0 };
> + struct unicam_buffer *buf;
> + unsigned long flags;
> + unsigned int i;
> + int ret;
> +
> + node->streaming = true;

Locking seems to be completely missing from the driver. I'll comment
more on that on v3, it will be easier after all the other cleanups.

> +
> + dev->sequence = 0;
> + ret = unicam_runtime_get(dev);
> + if (ret < 0) {
> + dev_dbg(dev->v4l2_dev.dev, "unicam_runtime_get failed\n");

This is really not supposed to happen, dev_err() is appropriate.

> + goto err_streaming;
> + }
> +
> + ret = media_pipeline_start(node->video_dev.entity.pads, &node->pipe);
> + if (ret < 0) {
> + dev_err(dev->v4l2_dev.dev, "Failed to start media pipeline: %d\n", ret);

dev_dbg() here too.

> + goto err_pm_put;
> + }
> +
> + dev->active_data_lanes = dev->max_data_lanes;

You need to get the number of data lanes from the sensor subdev and
validate it to ensure it doesn't exceed the maximum.

> +
> + unicam_video_check_format(node);

Where's the return value check ?

> +
> + dev_dbg(dev->v4l2_dev.dev, "Running with %u data lanes\n",
> + dev->active_data_lanes);
> +
> + ret = clk_set_min_rate(dev->vpu_clock, MIN_VPU_CLOCK_RATE);
> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "failed to set up VPU clock\n");
> + goto error_pipeline;
> + }
> +
> + ret = clk_prepare_enable(dev->vpu_clock);
> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "Failed to enable VPU clock: %d\n", ret);
> + goto error_pipeline;
> + }
> +
> + ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "failed to set up CSI clock\n");
> + goto err_vpu_clock;
> + }
> +
> + ret = clk_prepare_enable(dev->clock);
> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "Failed to enable CSI clock: %d\n", ret);
> + goto err_vpu_clock;
> + }
> +
> + dev_dbg(dev->v4l2_dev.dev, "node %s\n", node->video_dev.name);
> +
> + spin_lock_irqsave(&node->dma_queue_lock, flags);
> + buf = list_first_entry(&node->dma_queue,
> + struct unicam_buffer, list);

This holds on a single line.

> + node->cur_frm = buf;
> + node->next_frm = buf;
> + list_del(&buf->list);
> + spin_unlock_irqrestore(&node->dma_queue_lock, flags);
> +
> + buffer_addr[i] =
> + vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);

This too.

> +
> + unicam_start_rx(dev, buffer_addr);
> +
> + ret = v4l2_subdev_call(&dev->sd, video, s_stream, 1);
> + if (ret < 0) {
> + dev_err(dev->v4l2_dev.dev, "stream on failed in subdev\n");
> + goto err_disable_unicam;
> + }

Do I understand correctly that all this will run twice, once when
VIDIOC_STREAMON is called on the image node, and once when it's called
on the metadata node ? That doesn't seem right. The stop_streaming
function is affected similarly.

> +
> + dev->clocks_enabled = true;
> + return 0;
> +
> +err_disable_unicam:
> + unicam_disable(dev);
> + clk_disable_unprepare(dev->clock);
> +err_vpu_clock:
> + if (clk_set_min_rate(dev->vpu_clock, 0))
> + dev_err(dev->v4l2_dev.dev, "failed to reset the VPU clock\n");
> + clk_disable_unprepare(dev->vpu_clock);
> +error_pipeline:
> + media_pipeline_stop(node->video_dev.entity.pads);
> +err_pm_put:
> + unicam_runtime_put(dev);
> +err_streaming:
> + unicam_return_buffers(node, VB2_BUF_STATE_QUEUED);
> + node->streaming = false;
> +
> + return ret;
> +}
> +
> +static void unicam_stop_streaming(struct vb2_queue *vq)
> +{
> + struct unicam_node *node = vb2_get_drv_priv(vq);
> + struct unicam_device *dev = node->dev;
> +
> + node->streaming = false;
> + /*
> + * Stop streaming the sensor and disable the peripheral.
> + * We cannot continue streaming embedded data with the
> + * image pad disabled.
> + */
> + if (v4l2_subdev_call(&dev->sd, video, s_stream, 0) < 0)
> + dev_err(dev->v4l2_dev.dev, "stream off failed in subdev\n");
> +
> + unicam_disable(dev);
> +
> + media_pipeline_stop(node->video_dev.entity.pads);
> +
> + if (dev->clocks_enabled) {

.stop_streaming() can only be called after a successful
.start_streaming() call, so you can drop the clocks_enabled field.

> + if (clk_set_min_rate(dev->vpu_clock, 0))
> + dev_err(dev->v4l2_dev.dev, "failed to reset the VPU clock\n");
> + clk_disable_unprepare(dev->vpu_clock);
> + clk_disable_unprepare(dev->clock);
> + dev->clocks_enabled = false;
> + }
> + unicam_runtime_put(dev);
> +
> + if (is_metadata_node(node)) {
> + /*
> + * Allow the hardware to spin in the dummy buffer.
> + * This is only really needed if the embedded data pad is
> + * disabled before the image pad.
> + */
> + unicam_wr_dma_addr(dev, node->dummy_buf_dma_addr,
> + DUMMY_BUF_SIZE, METADATA_NODE);
> + }
> +
> + /* Clear all queued buffers for the node */
> + unicam_return_buffers(node, VB2_BUF_STATE_ERROR);
> +}
> +
> +static const struct vb2_ops unicam_video_qops = {
> + .wait_prepare = vb2_ops_wait_prepare,
> + .wait_finish = vb2_ops_wait_finish,
> + .queue_setup = unicam_queue_setup,
> + .buf_prepare = unicam_buffer_prepare,
> + .buf_queue = unicam_buffer_queue,
> + .start_streaming = unicam_start_streaming,
> + .stop_streaming = unicam_stop_streaming,
> +};
> +
> +/* unicam capture driver file operations */
> +static const struct v4l2_file_operations unicam_fops = {
> + .owner = THIS_MODULE,
> + .open = v4l2_fh_open,
> + .release = vb2_fop_release,
> + .poll = vb2_fop_poll,
> + .unlocked_ioctl = video_ioctl2, /* V4L2 ioctl handler */

Drop the comment.

> + .mmap = vb2_fop_mmap,
> +};
> +
> +static int
> +unicam_async_bound(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *subdev,
> + struct v4l2_async_subdev *asd)
> +{
> + struct unicam_device *unicam = to_unicam_device(notifier->v4l2_dev);
> +
> + if (unicam->sensor) {
> + dev_info(unicam->v4l2_dev.dev, "subdev %s (Already set!!)",
> + subdev->name);
> + return 0;
> + }

This can't happen as we register a single asd only.

> +
> + unicam->sensor = subdev;
> + dev_dbg(unicam->v4l2_dev.dev, "Using sensor %s for capture\n", subdev->name);

Line wrap.

> +
> + return 0;
> +}
> +
> +static void unicam_release(struct kref *kref)
> +{
> + struct unicam_device *unicam =
> + container_of(kref, struct unicam_device, kref);
> +
> + v4l2_ctrl_handler_free(&unicam->ctrl_handler);
> + media_device_cleanup(&unicam->mdev);
> +
> + if (unicam->sensor_state)
> + __v4l2_subdev_state_free(unicam->sensor_state);
> +
> + kfree(unicam);
> +}
> +
> +static void unicam_put(struct unicam_device *unicam)
> +{
> + kref_put(&unicam->kref, unicam_release);
> +}
> +
> +static void unicam_get(struct unicam_device *unicam)
> +{
> + kref_get(&unicam->kref);
> +}
> +
> +static void unicam_node_release(struct video_device *vdev)
> +{
> + struct unicam_node *node = video_get_drvdata(vdev);
> +
> + unicam_put(node->dev);
> +}
> +
> +static void unicam_mc_set_default_format(struct unicam_node *node)
> +{
> + dev_dbg(node->dev->v4l2_dev.dev, "Set default format for %s node\n",

node->dev->dev should do, no need to go through v4l2_dev here. But I'd
drop the message, I don't think it brings much value.

> + node->node_id == IMAGE_NODE ? "image" : "metadata");
> +
> + if (is_image_node(node)) {
> + struct v4l2_pix_format *pix_fmt = &node->v_fmt.fmt.pix;
> +
> + pix_fmt->width = 640;
> + pix_fmt->height = 480;
> + pix_fmt->field = V4L2_FIELD_NONE;
> + pix_fmt->colorspace = V4L2_COLORSPACE_SRGB;
> + pix_fmt->ycbcr_enc = V4L2_YCBCR_ENC_601;
> + pix_fmt->quantization = V4L2_QUANTIZATION_LIM_RANGE;
> + pix_fmt->xfer_func = V4L2_XFER_FUNC_SRGB;
> + pix_fmt->pixelformat = formats[0].fourcc;
> + unicam_calc_format_size_bpl(node->dev, &formats[0],
> + &node->v_fmt);
> + node->v_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +
> + node->fmt = &formats[0];
> + } else {
> + const struct unicam_fmt *fmt;
> +
> + /* Fix this node format as embedded data. */
> + fmt = find_format_by_code(MEDIA_BUS_FMT_METADATA_8);
> + node->v_fmt.fmt.meta.dataformat = fmt->fourcc;
> + node->fmt = fmt;

Move this to the end to group all v_fmt initialization together.

> + node->v_fmt.fmt.meta.buffersize = UNICAM_EMBEDDED_SIZE;
> + node->embedded_lines = 1;

This belongs to the called.

> + node->v_fmt.type = V4L2_BUF_TYPE_META_CAPTURE;
> + }
> +}
> +
> +static int register_node(struct unicam_device *unicam, struct unicam_node *node,
> + enum v4l2_buf_type type)

Replace the type parameter with a enum unicam_node_type, that will look
cleaner in

> +{
> + struct video_device *vdev;
> + struct vb2_queue *q;
> + int ret;
> +
> + node->dev = unicam;
> + node->node_id = type == V4L2_BUF_TYPE_VIDEO_CAPTURE ?
> + IMAGE_NODE :
> + METADATA_NODE;
> +
> + spin_lock_init(&node->dma_queue_lock);
> + mutex_init(&node->lock);
> +
> + vdev = &node->video_dev;
> + /*
> + * If the sensor subdevice has any controls, associate the node
> + * with the ctrl handler to allow access from userland.
> + */
> + if (!list_empty(&unicam->ctrl_handler.ctrls))
> + vdev->ctrl_handler = &unicam->ctrl_handler;

Drop this, and move the vdev assignment below, just before it gets used.

/* Initialize the videobuf2 queue. */
> +
> + q = &node->buffer_queue;
> + q->type = type;
> + q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;

Drop VB2_READ, that shouldn't be used.

> + q->drv_priv = node;
> + q->ops = &unicam_video_qops;
> + q->mem_ops = &vb2_dma_contig_memops;
> + q->buf_struct_size = sizeof(struct unicam_buffer);
> + q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> + q->lock = &node->lock;
> + q->min_buffers_needed = 1;
> + q->dev = &unicam->pdev->dev;
> +
> + ret = vb2_queue_init(q);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "vb2_queue_init() failed\n");
> + return ret;
> + }
> +
> + INIT_LIST_HEAD(&node->dma_queue);

Move this to the beginning of the function with the rest of the node
initialization.

/* Initialize the video device. */

> +
> + vdev->release = unicam_node_release;
> + vdev->fops = &unicam_fops;
> + vdev->ioctl_ops = &unicam_mc_ioctl_ops;
> + vdev->v4l2_dev = &unicam->v4l2_dev;
> + vdev->vfl_dir = VFL_DIR_RX;
> + vdev->queue = q;
> + vdev->lock = &node->lock;
> + vdev->device_caps = (type == V4L2_BUF_TYPE_VIDEO_CAPTURE) ?

No need for parentheses.

> + V4L2_CAP_VIDEO_CAPTURE : V4L2_CAP_META_CAPTURE;
> + vdev->device_caps |= V4L2_CAP_READWRITE | V4L2_CAP_STREAMING | V4L2_CAP_IO_MC;

Drop V4L2_CAP_READWRITE.

> + vdev->entity.ops = &unicam_mc_entity_ops;
> +
> + /* Define the device names */
> + snprintf(vdev->name, sizeof(vdev->name), "%s-%s", UNICAM_MODULE_NAME,
> + type == V4L2_BUF_TYPE_VIDEO_CAPTURE ? "image" : "embedded");
> +
> + video_set_drvdata(vdev, node);
> + if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
> + node->pad.flags = MEDIA_PAD_FL_SINK;
> + media_entity_pads_init(&vdev->entity, 1, &node->pad);

Error check.

> +
> + node->dummy_buf_cpu_addr = dma_alloc_coherent(&unicam->pdev->dev,
> + DUMMY_BUF_SIZE,
> + &node->dummy_buf_dma_addr,
> + GFP_KERNEL);
> + if (!node->dummy_buf_cpu_addr) {
> + dev_err(unicam->v4l2_dev.dev, "Unable to allocate dummy buffer.\n");
> + return -ENOMEM;
> + }
> +
> + ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Unable to register video device %s\n",
> + vdev->name);
> + return ret;
> + }
> +
> + /*
> + * Acquire a reference to unicam, which will be released when the video
> + * device will be unregistered and userspace will have closed all open
> + * file handles.
> + */
> + unicam_get(unicam);

This is error-prone. References should be acquired when stored, so this
should be moved to the beginning of the function, and written as

node->dev = unicam_get(unicam);

(you'll need to modify the function prototype to return the pointer).
You can then drop the comment. You will also to add error handling to
this function, as the reference will be released by
unicam_node_release(), which is called only after successful
registration of the video device. All error paths before registration
will thus need to release the reference (possibly with a goto
err_unicam_put)..

> + node->registered = true;
> +
> + ret = media_create_pad_link(&unicam->sd.entity,
> + node->src_pad_id,

unicam->sd is the unicam sd, node->src_pad_id is documented as being the
source pad of the sensor. This is wrong.

> + &node->video_dev.entity,
> + 0,
> + MEDIA_LNK_FL_ENABLED |
> + MEDIA_LNK_FL_IMMUTABLE);
> + if (ret)
> + dev_err(unicam->v4l2_dev.dev, "Unable to create pad link for %s",
> + unicam->sensor->name);

return ret;
}

> +
> + unicam_mc_set_default_format(node);

Call this before registering the video device, otherwise it can race
with userspace.

> +
> + return ret;

return 0;

> +}
> +
> +static void unregister_nodes(struct unicam_device *unicam)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(unicam->node); i++) {
> + struct unicam_node *node = &unicam->node[i];
> +
> + if (node->dummy_buf_cpu_addr) {
> + dma_free_coherent(&unicam->pdev->dev, DUMMY_BUF_SIZE,
> + node->dummy_buf_cpu_addr,
> + node->dummy_buf_dma_addr);
> + }

No need for curly braces.

> +
> + if (node->registered) {
> + node->registered = false;
> + video_unregister_device(&node->video_dev);

Swap the two lines.

> + }
> + }
> +}
> +
> +static int unicam_async_complete(struct v4l2_async_notifier *notifier)
> +{
> + struct unicam_device *unicam = to_unicam_device(notifier->v4l2_dev);
> + unsigned int i, source_pads = 0;
> + int ret;
> + static struct lock_class_key key;
> +
> + unicam->v4l2_dev.notify = unicam_notify;
> +
> + unicam->sensor_state = __v4l2_subdev_state_alloc(unicam->sensor,
> + "unicam:state->lock",
> + &key);

You never use sensor_state.

> + if (!unicam->sensor_state)
> + return -ENOMEM;
> +
> + for (i = 0; i < unicam->sd.entity.num_pads; i++) {
> + if (unicam->sd.entity.pads[i].flags & MEDIA_PAD_FL_SOURCE) {
> + if (source_pads < MAX_NODES) {
> + unicam->node[source_pads].src_pad_id = i;
> + dev_dbg(unicam->v4l2_dev.dev, "source pad %u is index %u\n",
> + source_pads, i);
> + }
> + source_pads++;
> + }
> + }
> + if (!source_pads) {
> + dev_err(unicam->v4l2_dev.dev, "No source pads on sensor.\n");
> + goto unregister;
> + }

You're not looking at the sensor here, unicam->sd is the unicam subdev.
Furthermore, you're hardcoding the source pad of the sensor to 0 below
when creating the link. And in any case, that's not how it's supposed to
be done, a source subdev could have multiple source pads, you need to
identify the correct one from the device tree.

The right way to handle this is to replace the call to
media_create_pad_link() with v4l2_create_fwnode_links_to_pad(). This can
be done in the .bound() handler.

> +
> + ret = register_node(unicam, &unicam->node[IMAGE_NODE],
> + V4L2_BUF_TYPE_VIDEO_CAPTURE);

Replace the type parameter with a enum unicam_node_type, so this will
become

ret = register_node(unicam, &unicam->node[IMAGE_NODE], IMAGE_NODE);

which is less error-prone. You could even drop the second parameters:

ret = register_node(unicam, IMAGE_NODE);

> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Unable to register image video device.\n");
> + goto unregister;
> + }
> +
> + /* \todo: check before :-) */
> + unicam->sensor_embedded_data = true;

Check what ? In any case I don't think this belongs here.

> +
> + ret = register_node(unicam, &unicam->node[METADATA_NODE],
> + V4L2_BUF_TYPE_META_CAPTURE);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Unable to register metadata video device.\n");
> + goto unregister;
> + }
> +
> + ret = media_create_pad_link(&unicam->sensor->entity,
> + 0,
> + &unicam->sd.entity,
> + UNICAM_SD_PAD_SINK,
> + MEDIA_LNK_FL_ENABLED |
> + MEDIA_LNK_FL_IMMUTABLE);
> + if (ret)
> + dev_err(unicam->v4l2_dev.dev, "Unable to create pad link for %s",
> + unicam->sensor->name);
> +
> + ret = v4l2_device_register_subdev_nodes(&unicam->v4l2_dev);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Unable to register subdev nodes.\n");
> + goto unregister;
> + }
> +
> + /*
> + * Release the initial reference, all references are now owned by the
> + * video devices.
> + */
> + unicam_put(unicam);
> + return 0;
> +
> +unregister:
> + unregister_nodes(unicam);
> + unicam_put(unicam);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_async_notifier_operations unicam_async_ops = {
> + .bound = unicam_async_bound,
> + .complete = unicam_async_complete,
> +};
> +
> +static int of_unicam_connect_subdevs(struct unicam_device *dev)
> +{
> + struct platform_device *pdev = dev->pdev;
> + struct v4l2_fwnode_endpoint ep = { };
> + struct device_node *ep_node;
> + struct device_node *sensor_node;
> + unsigned int lane;
> + int ret = -EINVAL;
> +
> + if (of_property_read_u32(pdev->dev.of_node, "num-data-lanes",
> + &dev->max_data_lanes) < 0) {
> + dev_err(dev->v4l2_dev.dev, "number of data lanes not set\n");
> + return -EINVAL;
> + }
> +
> + /* Get the local endpoint and remote device. */
> + ep_node = of_graph_get_next_endpoint(pdev->dev.of_node, NULL);

Use of_graph_get_endpoint_by_regs(node, 0, -1).

> + if (!ep_node) {
> + dev_dbg(dev->v4l2_dev.dev, "can't get next endpoint\n");

dev_dbg(dev->v4l2_dev.dev, "No endpoint\n");

> + return -EINVAL;
> + }
> +
> + dev_dbg(dev->v4l2_dev.dev, "ep_node is %pOF\n", ep_node);

You can drop this.

> +
> + sensor_node = of_graph_get_remote_port_parent(ep_node);
> + if (!sensor_node) {
> + dev_dbg(dev->v4l2_dev.dev, "can't get remote parent\n");
> + goto cleanup_exit;
> + }
> +
> + dev_dbg(dev->v4l2_dev.dev, "found subdevice %pOF\n", sensor_node);

There's no subdev yet, we're dealing with DT here.

dev_dbg(dev->v4l2_dev.dev, "found source device %pOF\n", sensor_node);

But I would actually drop all this. The sensor_node is only used in
debug or error messages, so you could remove it and use ep_node in those
messages instead. Or even better, drop the "subdevice %pOF: " prefix in
the messages, that will make the code simpler.

> +
> + /* Parse the local endpoint and validate its configuration. */
> + v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);

Use v4l2_fwnode_endpoint_alloc_parse() and check for errors (and update
the error cleanup path accordingly).

> +
> + dev_dbg(dev->v4l2_dev.dev, "parsed local endpoint, bus_type %u\n",
> + ep.bus_type);
> +
> + dev->bus_type = ep.bus_type;
> +
> + switch (ep.bus_type) {
> + case V4L2_MBUS_CSI2_DPHY:
> + switch (ep.bus.mipi_csi2.num_data_lanes) {
> + case 1:
> + case 2:
> + case 4:
> + break;
> +
> + default:
> + dev_err(dev->v4l2_dev.dev, "subdevice %pOF: %u data lanes not supported\n",
> + sensor_node,
> + ep.bus.mipi_csi2.num_data_lanes);
> + goto cleanup_exit;
> + }
> +
> + for (lane = 0; lane < ep.bus.mipi_csi2.num_data_lanes; lane++) {
> + if (ep.bus.mipi_csi2.data_lanes[lane] != lane + 1) {
> + dev_err(dev->v4l2_dev.dev, "subdevice %pOF: data lanes reordering not supported\n",
> + sensor_node);
> + goto cleanup_exit;
> + }
> + }
> +
> + if (ep.bus.mipi_csi2.num_data_lanes > dev->max_data_lanes) {
> + dev_err(dev->v4l2_dev.dev, "subdevice requires %u data lanes when %u are supported\n",

s/subdevice/endpoint/

> + ep.bus.mipi_csi2.num_data_lanes,
> + dev->max_data_lanes);
> + }
> +
> + dev->max_data_lanes = ep.bus.mipi_csi2.num_data_lanes;
> + dev->bus_flags = ep.bus.mipi_csi2.flags;
> +
> + break;
> +
> + case V4L2_MBUS_CCP2:
> + if (ep.bus.mipi_csi1.clock_lane != 0 ||
> + ep.bus.mipi_csi1.data_lane != 1) {
> + dev_err(dev->v4l2_dev.dev, "subdevice %pOF: unsupported lanes configuration\n",
> + sensor_node);
> + goto cleanup_exit;
> + }
> +
> + dev->max_data_lanes = 1;
> + dev->bus_flags = ep.bus.mipi_csi1.strobe;
> + break;

I wonder if this driver will ever be used with a CCP2 sensor.

> +
> + default:
> + /* Unsupported bus type */
> + dev_err(dev->v4l2_dev.dev, "subdevice %pOF: unsupported bus type %u\n",
> + sensor_node, ep.bus_type);
> + goto cleanup_exit;
> + }
> +
> + dev_dbg(dev->v4l2_dev.dev, "subdevice %pOF: %s bus, %u data lanes, flags=0x%08x\n",
> + sensor_node,
> + dev->bus_type == V4L2_MBUS_CSI2_DPHY ? "CSI-2" : "CCP2",
> + dev->max_data_lanes, dev->bus_flags);
> +
> + /* Initialize and register the async notifier. */
> + v4l2_async_nf_init(&dev->notifier);
> + dev->notifier.ops = &unicam_async_ops;
> +
> + dev->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> + dev->asd.match.fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep_node));
> + ret = v4l2_async_nf_add_subdev(&dev->notifier, &dev->asd);

The asd must be dynamically allocated as stated by the documentation of
__v4l2_async_nf_add_subdev(). You can use
v4l2_async_nf_add_fwnode_remote() to simplify this.

> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "Error adding subdevice: %d\n", ret);
> + goto cleanup_exit;
> + }
> +
> + ret = v4l2_async_nf_register(&dev->v4l2_dev, &dev->notifier);
> + if (ret) {
> + dev_err(dev->v4l2_dev.dev, "Error registering async notifier: %d\n", ret);
> + ret = -EINVAL;
> + }
> +
> +cleanup_exit:
> + of_node_put(sensor_node);
> + of_node_put(ep_node);
> +
> + return ret;
> +}
> +
> +static int bcm2835_media_dev_init(struct unicam_device *unicam,
> + struct platform_device *pdev)
> +{
> + int ret = 0;
> +
> + unicam->mdev.dev = &pdev->dev;
> + strscpy(unicam->mdev.model, UNICAM_MODULE_NAME,
> + sizeof(unicam->mdev.model));
> + strscpy(unicam->mdev.serial, "", sizeof(unicam->mdev.serial));
> + snprintf(unicam->mdev.bus_info, sizeof(unicam->mdev.bus_info),
> + "platform:%s", dev_name(&pdev->dev));
> + unicam->mdev.hw_revision = 0;
> +
> + media_device_init(&unicam->mdev);
> +
> + unicam->v4l2_dev.mdev = &unicam->mdev;
> +
> + ret = v4l2_device_register(&pdev->dev, &unicam->v4l2_dev);

return v4l2_device_register(&pdev->dev, &unicam->v4l2_dev);

> +
> + return ret;
> +}
> +
> +/* Internal subdev */
> +
> +static int _unicam_subdev_set_routing(struct v4l2_subdev *sd,

__ is more conventional.

> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_krouting *routing)
> +{
> + static const struct v4l2_mbus_framefmt format = {
> + .width = 640,
> + .height = 480,
> + .code = MEDIA_BUS_FMT_UYVY8_2X8,
> + .field = V4L2_FIELD_NONE,
> + .colorspace = V4L2_COLORSPACE_SRGB,
> + .ycbcr_enc = V4L2_YCBCR_ENC_601,
> + .quantization = V4L2_QUANTIZATION_LIM_RANGE,
> + .xfer_func = V4L2_XFER_FUNC_SRGB,
> + .flags = 0,
> + };

As this should match the values in unicam_mc_set_default_format(), can
you move this structure out of the function, and use it to initialize
the pix_fmt fields in unicam_mc_set_default_format() ?

> + int ret;
> +
> + ret = v4l2_subdev_routing_validate_1_to_1(routing);
> + if (ret)
> + return ret;
> +
> + v4l2_subdev_lock_state(state);
> +
> + ret = v4l2_subdev_set_routing_with_fmt(sd, state, routing, &format);
> +
> + v4l2_subdev_unlock_state(state);
> +
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int unicam_subdev_set_routing(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + enum v4l2_subdev_format_whence which,
> + struct v4l2_subdev_krouting *routing)
> +{
> + struct unicam_device *unicam = sd_to_unicam_device(sd);
> +
> + if (which == V4L2_SUBDEV_FORMAT_ACTIVE && unicam->streaming)
> + return -EBUSY;
> +
> + return _unicam_subdev_set_routing(sd, state, routing);
> +}
> +
> +static int unicam_subdev_init_cfg(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state)
> +{
> + struct v4l2_subdev_route routes[] = {
> + {
> + .sink_pad = 0,
> + .sink_stream = 0,
> + .source_pad = 1,

You have macros you can use for the pad numbers.

> + .source_stream = 0,
> + .flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
> + },
> + };
> +
> + struct v4l2_subdev_krouting routing = {
> + .num_routes = ARRAY_SIZE(routes),
> + .routes = routes,
> + };
> +
> + /* Initialize routing to single route to the fist source pad */
> + return _unicam_subdev_set_routing(sd, state, &routing);
> +}
> +
> +static int unicam_subdev_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + int ret = 0;
> +
> + v4l2_subdev_lock_state(state);
> +
> + /* No transcoding, source and sink codes must match. */
> + if (unicam_sd_pad_is_source(code->pad)) {
> + struct v4l2_mbus_framefmt *fmt;
> +
> + if (code->index > 0) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + fmt = v4l2_subdev_state_get_opposite_stream_format(state,
> + code->pad,
> + code->stream);
> + if (!fmt) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + code->code = fmt->code;
> + } else {
> + if (code->index >= ARRAY_SIZE(formats)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + code->code = formats[code->index].code;
> + }
> +
> +out:
> + v4l2_subdev_unlock_state(state);
> +
> + return ret;
> +}
> +
> +static int unicam_subdev_start_streaming(struct unicam_device *unicam)
> +{
> + const struct v4l2_subdev_krouting *routing;
> + struct v4l2_subdev_state *state;
> + int ret = 0;

No need to initialize ret to 0.

> +
> + state = v4l2_subdev_lock_active_state(&unicam->sd);
> +
> + routing = &state->routing;
> +
> + v4l2_subdev_unlock_state(state);

As a piece of conceptual art, maybe, but as useful code, I have some
doubts.

> +
> + unicam->streaming = true;
> +
> + ret = v4l2_subdev_call(unicam->sensor, video, s_stream, 1);
> + if (ret) {
> + v4l2_subdev_call(unicam->sensor, video, s_stream, 0);

If .s_stream(1) fails, why do you need to call .s_stream(0) ?

> + unicam->streaming = false;

Drop this, and move the unicam->streaming = true line below.

> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int unicam_subdev_stop_streaming(struct unicam_device *unicam)
> +{
> + v4l2_subdev_call(unicam->sensor, video, s_stream, 0);
> +
> + unicam->streaming = false;
> +
> + return 0;
> +}
> +
> +static int unicam_subdev_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> + struct unicam_device *unicam = sd_to_unicam_device(sd);
> +
> + if (enable)
> + return unicam_subdev_start_streaming(unicam);
> + else
> + return unicam_subdev_stop_streaming(unicam);
> + return 0;

Drop the last line.

> +}
> +
> +static int unicam_subdev_set_pad_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_format *format)
> +{
> + struct unicam_device *unicam = sd_to_unicam_device(sd);
> + struct v4l2_mbus_framefmt *fmt;
> + int ret = 0;
> +
> + if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE && unicam->streaming)
> + return -EBUSY;
> +
> + /* No transcoding, source and sink formats must match. */
> + if (unicam_sd_pad_is_source(format->pad))
> + return v4l2_subdev_get_fmt(sd, state, format);
> +
> + // TODO: implement fmt validation

That's a candidate for v3.

> +
> + v4l2_subdev_lock_state(state);
> +
> + fmt = v4l2_state_get_stream_format(state, format->pad, format->stream);
> + if (!fmt) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + *fmt = format->format;
> +
> + fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
> + format->stream);
> + if (!fmt) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + *fmt = format->format;

Let's avoid applying the format on one pad to then fail on the other
pad.

sink_format = v4l2_state_get_stream_format(state, format->pad,
format->stream);
source_format = v4l2_subdev_state_get_opposite_stream_format(state,
format->pad,
format->stream);
if (!sink_format || !source_format) {
ret = -EINVAL;
goto out;
}

*sink_format = format->format;
*source_format = format->format;

> +
> +out:
> + v4l2_subdev_unlock_state(state);
> +
> + return ret;
> +}
> +
> +static int unicam_subdev_enum_frame_size(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_frame_size_enum *fse)
> +{
> + const struct unicam_fmt *fmtinfo;
> + int ret = 0;
> +
> + if (fse->index > 0)
> + return -EINVAL;
> +
> + v4l2_subdev_lock_state(state);
> +
> + /* No transcoding, source and sink formats must match. */
> + if (unicam_sd_pad_is_source(fse->pad)) {
> + struct v4l2_mbus_framefmt *fmt;
> +
> + fmt = v4l2_subdev_state_get_opposite_stream_format(state,
> + fse->pad,
> + fse->stream);
> +

You can drop this blank line.

> + if (!fmt) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + if (fse->code != fmt->code) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + fse->min_width = fmt->width;
> + fse->max_width = fmt->width;
> + fse->min_height = fmt->height;
> + fse->max_height = fmt->height;
> + } else {
> + fmtinfo = find_format_by_code(fse->code);
> + if (!fmtinfo) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + fse->min_width = MIN_WIDTH * 8 / ALIGN(fmtinfo->depth, 8);
> + fse->max_width = MAX_WIDTH * 8 / ALIGN(fmtinfo->depth, 8);
> + fse->min_height = MIN_HEIGHT;
> + fse->max_height = MAX_HEIGHT;
> + }
> +
> +out:
> + v4l2_subdev_unlock_state(state);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_subdev_video_ops unicam_subdev_video_ops = {
> + .s_stream = unicam_subdev_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops unicam_subdev_pad_ops = {
> + .init_cfg = unicam_subdev_init_cfg,
> + .enum_mbus_code = unicam_subdev_enum_mbus_code,
> + .get_fmt = v4l2_subdev_get_fmt,
> + .set_fmt = unicam_subdev_set_pad_format,
> + .set_routing = unicam_subdev_set_routing,
> + .enum_frame_size = unicam_subdev_enum_frame_size,
> +};
> +
> +static const struct v4l2_subdev_ops unicam_subdev_ops = {
> + .video = &unicam_subdev_video_ops,
> + .pad = &unicam_subdev_pad_ops,
> +};
> +
> +static struct media_entity_operations unicam_subdev_media_ops = {

static const

> + .link_validate = v4l2_subdev_link_validate,
> + .has_route = v4l2_subdev_has_route,
> +};
> +
> +static int unicam_probe(struct platform_device *pdev)
> +{
> + struct unicam_device *unicam;
> + int ret = 0;
> + int i;
> +
> + unicam = kzalloc(sizeof(*unicam), GFP_KERNEL);
> + if (!unicam)
> + return -ENOMEM;
> +
> + kref_init(&unicam->kref);
> + unicam->pdev = pdev;
> +
> + unicam->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(unicam->base)) {
> + dev_err(unicam->v4l2_dev.dev, "Failed to get main io block\n");

Let's use unicam->dev to access the struct device, especially given that
unicam->v4l2_dev is only initialized below when calling
bcm2835_media_dev_init().

This message can actually br dropped, devm_platform_ioremap_resource()
already prints an error.

> + ret = PTR_ERR(unicam->base);
> + goto err_unicam_put;
> + }
> +
> + unicam->clk_gate_base = devm_platform_ioremap_resource(pdev, 1);
> + if (IS_ERR(unicam->clk_gate_base)) {
> + dev_err(unicam->v4l2_dev.dev, "Failed to get 2nd io block\n");

Same here.

> + ret = PTR_ERR(unicam->clk_gate_base);
> + goto err_unicam_put;
> + }
> +
> + unicam->clock = devm_clk_get(&pdev->dev, "lp");
> + if (IS_ERR(unicam->clock)) {
> + dev_err(unicam->v4l2_dev.dev, "Failed to get lp clock\n");
> + ret = PTR_ERR(unicam->clock);
> + goto err_unicam_put;
> + }
> +
> + unicam->vpu_clock = devm_clk_get(&pdev->dev, "vpu");
> + if (IS_ERR(unicam->vpu_clock)) {
> + dev_err(unicam->v4l2_dev.dev, "Failed to get vpu clock\n");
> + ret = PTR_ERR(unicam->vpu_clock);
> + goto err_unicam_put;
> + }

Could the clock bulk API help here ?

> +
> + ret = platform_get_irq(pdev, 0);
> + if (ret <= 0) {
> + dev_err(&pdev->dev, "No IRQ resource\n");
> + ret = -EINVAL;
> + goto err_unicam_put;
> + }
> +
> + ret = devm_request_irq(&pdev->dev, ret, unicam_isr, 0,
> + "unicam_capture0", unicam);
> + if (ret) {
> + dev_err(&pdev->dev, "Unable to request interrupt\n");
> + ret = -EINVAL;
> + goto err_unicam_put;
> + }
> +
> + ret = bcm2835_media_dev_init(unicam, pdev);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev,
> + "Unable to register v4l2 device.\n");
> + goto err_unicam_put;
> + }
> +
> + ret = media_device_register(&unicam->mdev);
> + if (ret < 0) {
> + dev_err(unicam->v4l2_dev.dev,
> + "Unable to register media-controller device.\n");
> + goto err_v4l2_unregister;
> + }
> +
> + /* Reserve space for the controls */
> + ret = v4l2_ctrl_handler_init(&unicam->ctrl_handler, 16);
> + if (ret < 0)
> + goto err_media_unregister;

The control handler is unused, drop it.

> +
> + /* set the driver data in platform device */
> + platform_set_drvdata(pdev, unicam);
> +
> + dev_dbg(unicam->v4l2_dev.dev, "Initialize internal subdev");

You can drop this.

> + v4l2_subdev_init(&unicam->sd, &unicam_subdev_ops);
> + v4l2_set_subdevdata(&unicam->sd, unicam);
> + unicam->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> + unicam->sd.dev = &pdev->dev;
> + unicam->sd.owner = THIS_MODULE;
> + unicam->sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_MULTIPLEXED;
> + snprintf(unicam->sd.name, sizeof(unicam->sd.name), "unicam-subdev");
> +
> + unicam->pads[UNICAM_SD_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> +
> + for (i = UNICAM_SD_PAD_FIRST_SOURCE; i < UNICAM_SD_NUM_PADS; ++i)
> + unicam->pads[i].flags = MEDIA_PAD_FL_SOURCE;

unicam->pads[UNICAM_SD_PAD_SOURCE_IMAGE].flags = MEDIA_PAD_FL_SOURCE;
unicam->pads[UNICAM_SD_PAD_SOURCE_META].flags = MEDIA_PAD_FL_SOURCE;

> + unicam->sd.entity.ops = &unicam_subdev_media_ops;
> + ret = media_entity_pads_init(&unicam->sd.entity,
> + ARRAY_SIZE(unicam->pads), unicam->pads);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Could not init media controller for subdev");
> + goto err_subdev_unregister;
> + }
> +
> + ret = v4l2_subdev_init_finalize(&unicam->sd);
> + if (ret) {
> + dev_err(unicam->v4l2_dev.dev, "Could not finalize init for subdev");
> + goto err_entity_cleanup;
> + }
> +
> + ret = v4l2_device_register_subdev(&unicam->v4l2_dev, &unicam->sd);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to register internal subdev\n");
> + goto err_subdev_unregister;
> + }

Let's split initialization and registration of the subdev to a separate
function, placed above with the subdev operations.

> +
> + ret = of_unicam_connect_subdevs(unicam);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to connect subdevs\n");
> + goto err_subdev_unregister;
> + }
> +
> + /* Enable the block power domain */
> + pm_runtime_enable(&pdev->dev);
> +
> + return 0;
> +
> +err_subdev_unregister:
> + v4l2_subdev_cleanup(&unicam->sd);
> +err_entity_cleanup:
> + media_entity_cleanup(&unicam->sd.entity);
> +err_media_unregister:
> + media_device_unregister(&unicam->mdev);
> +err_v4l2_unregister:
> + v4l2_device_unregister(&unicam->v4l2_dev);
> +err_unicam_put:
> + unicam_put(unicam);
> +
> + return ret;
> +}
> +
> +static int unicam_remove(struct platform_device *pdev)
> +{
> + struct unicam_device *unicam = platform_get_drvdata(pdev);
> +
> + v4l2_async_nf_unregister(&unicam->notifier);
> + v4l2_device_unregister(&unicam->v4l2_dev);
> + media_device_unregister(&unicam->mdev);
> + unregister_nodes(unicam);

I'm a bit worried there could be race conditions with userspace here.
For instance, calling v4l2_async_nf_unregister() will result in
v4l2_device_unregister_subdev() being called on the sensor subdev, which
may race with userspace starting capture on a video node. The following
order would, I think be safer:

unregister_nodes(unicam);
v4l2_device_unregister(&unicam->v4l2_dev);
media_device_unregister(&unicam->mdev);
v4l2_async_nf_unregister(&unicam->notifier);

But this will cause a problem, when unregistering device nodes, the last
reference to unicam would be dropped. I think you could drop the calls
to unicam_put() from unicam_async_complete(), and add a unicam_put()
call here. Dave, does that sound good to you ?

> +
> + pm_runtime_disable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id unicam_of_match[] = {
> + { .compatible = "brcm,bcm2835-unicam", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, unicam_of_match);
> +
> +static struct platform_driver unicam_driver = {
> + .probe = unicam_probe,
> + .remove = unicam_remove,
> + .driver = {
> + .name = UNICAM_MODULE_NAME,
> + .of_match_table = of_match_ptr(unicam_of_match),
> + },
> +};
> +
> +module_platform_driver(unicam_driver);
> +
> +MODULE_AUTHOR("Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("BCM2835 Unicam driver");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION(UNICAM_VERSION);
> diff --git a/drivers/media/platform/bcm2835/vc4-regs-unicam.h b/drivers/media/platform/bcm2835/vc4-regs-unicam.h
> new file mode 100644
> index 000000000000..ae059a171d0f
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/vc4-regs-unicam.h
> @@ -0,0 +1,253 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +/*
> + * Copyright (C) 2017-2020 Raspberry Pi Trading.
> + * Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> + */
> +
> +#ifndef VC4_REGS_UNICAM_H
> +#define VC4_REGS_UNICAM_H
> +
> +/*
> + * The following values are taken from files found within the code drop
> + * made by Broadcom for the BCM21553 Graphics Driver, predominantly in
> + * brcm_usrlib/dag/vmcsx/vcinclude/hardware_vc4.h.
> + * They have been modified to be only the register offset.
> + */
> +#define UNICAM_CTRL 0x000
> +#define UNICAM_STA 0x004
> +#define UNICAM_ANA 0x008
> +#define UNICAM_PRI 0x00c
> +#define UNICAM_CLK 0x010
> +#define UNICAM_CLT 0x014
> +#define UNICAM_DAT0 0x018
> +#define UNICAM_DAT1 0x01c
> +#define UNICAM_DAT2 0x020
> +#define UNICAM_DAT3 0x024
> +#define UNICAM_DLT 0x028
> +#define UNICAM_CMP0 0x02c
> +#define UNICAM_CMP1 0x030
> +#define UNICAM_CAP0 0x034
> +#define UNICAM_CAP1 0x038
> +#define UNICAM_ICTL 0x100
> +#define UNICAM_ISTA 0x104
> +#define UNICAM_IDI0 0x108
> +#define UNICAM_IPIPE 0x10c
> +#define UNICAM_IBSA0 0x110
> +#define UNICAM_IBEA0 0x114
> +#define UNICAM_IBLS 0x118
> +#define UNICAM_IBWP 0x11c
> +#define UNICAM_IHWIN 0x120
> +#define UNICAM_IHSTA 0x124
> +#define UNICAM_IVWIN 0x128
> +#define UNICAM_IVSTA 0x12c
> +#define UNICAM_ICC 0x130
> +#define UNICAM_ICS 0x134
> +#define UNICAM_IDC 0x138
> +#define UNICAM_IDPO 0x13c
> +#define UNICAM_IDCA 0x140
> +#define UNICAM_IDCD 0x144
> +#define UNICAM_IDS 0x148
> +#define UNICAM_DCS 0x200
> +#define UNICAM_DBSA0 0x204
> +#define UNICAM_DBEA0 0x208
> +#define UNICAM_DBWP 0x20c
> +#define UNICAM_DBCTL 0x300
> +#define UNICAM_IBSA1 0x304
> +#define UNICAM_IBEA1 0x308
> +#define UNICAM_IDI1 0x30c
> +#define UNICAM_DBSA1 0x310
> +#define UNICAM_DBEA1 0x314
> +#define UNICAM_MISC 0x400

Please add one tab before the value, to match the indentation of the
rest of the file.

> +
> +/*
> + * The following bitmasks are from the kernel released by Broadcom
> + * for Android - https://android.googlesource.com/kernel/bcm/
> + * The Rhea, Hawaii, and Java chips all contain the same VideoCore4
> + * Unicam block as BCM2835, as defined in eg
> + * arch/arm/mach-rhea/include/mach/rdb_A0/brcm_rdb_cam.h and similar.
> + * Values reworked to use the kernel BIT and GENMASK macros.
> + *
> + * Some of the bit mnenomics have been amended to match the datasheet.
> + */
> +/* UNICAM_CTRL Register */
> +#define UNICAM_CPE BIT(0)
> +#define UNICAM_MEM BIT(1)
> +#define UNICAM_CPR BIT(2)
> +#define UNICAM_CPM_MASK GENMASK(3, 3)
> +#define UNICAM_CPM_CSI2 0
> +#define UNICAM_CPM_CCP2 1
> +#define UNICAM_SOE BIT(4)
> +#define UNICAM_DCM_MASK GENMASK(5, 5)
> +#define UNICAM_DCM_STROBE 0
> +#define UNICAM_DCM_DATA 1
> +#define UNICAM_SLS BIT(6)
> +#define UNICAM_PFT_MASK GENMASK(11, 8)
> +#define UNICAM_OET_MASK GENMASK(20, 12)
> +
> +/* UNICAM_STA Register */
> +#define UNICAM_SYN BIT(0)
> +#define UNICAM_CS BIT(1)
> +#define UNICAM_SBE BIT(2)
> +#define UNICAM_PBE BIT(3)
> +#define UNICAM_HOE BIT(4)
> +#define UNICAM_PLE BIT(5)
> +#define UNICAM_SSC BIT(6)
> +#define UNICAM_CRCE BIT(7)
> +#define UNICAM_OES BIT(8)
> +#define UNICAM_IFO BIT(9)
> +#define UNICAM_OFO BIT(10)
> +#define UNICAM_BFO BIT(11)
> +#define UNICAM_DL BIT(12)
> +#define UNICAM_PS BIT(13)
> +#define UNICAM_IS BIT(14)
> +#define UNICAM_PI0 BIT(15)
> +#define UNICAM_PI1 BIT(16)
> +#define UNICAM_FSI_S BIT(17)
> +#define UNICAM_FEI_S BIT(18)
> +#define UNICAM_LCI_S BIT(19)
> +#define UNICAM_BUF0_RDY BIT(20)
> +#define UNICAM_BUF0_NO BIT(21)
> +#define UNICAM_BUF1_RDY BIT(22)
> +#define UNICAM_BUF1_NO BIT(23)
> +#define UNICAM_DI BIT(24)
> +
> +#define UNICAM_STA_MASK_ALL \
> + (UNICAM_DL + \
> + UNICAM_SBE + \
> + UNICAM_PBE + \
> + UNICAM_HOE + \
> + UNICAM_PLE + \
> + UNICAM_SSC + \
> + UNICAM_CRCE + \
> + UNICAM_IFO + \
> + UNICAM_OFO + \
> + UNICAM_PS + \
> + UNICAM_PI0 + \
> + UNICAM_PI1)

I'd use | instead of + to combine bits. Same below.

> +
> +/* UNICAM_ANA Register */
> +#define UNICAM_APD BIT(0)
> +#define UNICAM_BPD BIT(1)
> +#define UNICAM_AR BIT(2)
> +#define UNICAM_DDL BIT(3)
> +#define UNICAM_CTATADJ_MASK GENMASK(7, 4)
> +#define UNICAM_PTATADJ_MASK GENMASK(11, 8)
> +
> +/* UNICAM_PRI Register */
> +#define UNICAM_PE BIT(0)
> +#define UNICAM_PT_MASK GENMASK(2, 1)
> +#define UNICAM_NP_MASK GENMASK(7, 4)
> +#define UNICAM_PP_MASK GENMASK(11, 8)
> +#define UNICAM_BS_MASK GENMASK(15, 12)
> +#define UNICAM_BL_MASK GENMASK(17, 16)
> +
> +/* UNICAM_CLK Register */
> +#define UNICAM_CLE BIT(0)
> +#define UNICAM_CLPD BIT(1)
> +#define UNICAM_CLLPE BIT(2)
> +#define UNICAM_CLHSE BIT(3)
> +#define UNICAM_CLTRE BIT(4)
> +#define UNICAM_CLAC_MASK GENMASK(8, 5)
> +#define UNICAM_CLSTE BIT(29)
> +
> +/* UNICAM_CLT Register */
> +#define UNICAM_CLT1_MASK GENMASK(7, 0)
> +#define UNICAM_CLT2_MASK GENMASK(15, 8)
> +
> +/* UNICAM_DATn Registers */
> +#define UNICAM_DLE BIT(0)
> +#define UNICAM_DLPD BIT(1)
> +#define UNICAM_DLLPE BIT(2)
> +#define UNICAM_DLHSE BIT(3)
> +#define UNICAM_DLTRE BIT(4)
> +#define UNICAM_DLSM BIT(5)
> +#define UNICAM_DLFO BIT(28)
> +#define UNICAM_DLSTE BIT(29)
> +
> +#define UNICAM_DAT_MASK_ALL (UNICAM_DLSTE + UNICAM_DLFO)

This also needs an indentation fix, as well as UNICAM_ISTA_MASK_ALL.

> +
> +/* UNICAM_DLT Register */
> +#define UNICAM_DLT1_MASK GENMASK(7, 0)
> +#define UNICAM_DLT2_MASK GENMASK(15, 8)
> +#define UNICAM_DLT3_MASK GENMASK(23, 16)
> +
> +/* UNICAM_ICTL Register */
> +#define UNICAM_FSIE BIT(0)
> +#define UNICAM_FEIE BIT(1)
> +#define UNICAM_IBOB BIT(2)
> +#define UNICAM_FCM BIT(3)
> +#define UNICAM_TFC BIT(4)
> +#define UNICAM_LIP_MASK GENMASK(6, 5)
> +#define UNICAM_LCIE_MASK GENMASK(28, 16)
> +
> +/* UNICAM_IDI0/1 Register */
> +#define UNICAM_ID0_MASK GENMASK(7, 0)
> +#define UNICAM_ID1_MASK GENMASK(15, 8)
> +#define UNICAM_ID2_MASK GENMASK(23, 16)
> +#define UNICAM_ID3_MASK GENMASK(31, 24)
> +
> +/* UNICAM_ISTA Register */
> +#define UNICAM_FSI BIT(0)
> +#define UNICAM_FEI BIT(1)
> +#define UNICAM_LCI BIT(2)
> +
> +#define UNICAM_ISTA_MASK_ALL (UNICAM_FSI + UNICAM_FEI + UNICAM_LCI)
> +
> +/* UNICAM_IPIPE Register */
> +#define UNICAM_PUM_MASK GENMASK(2, 0)
> + /* Unpacking modes */
> + #define UNICAM_PUM_NONE 0
> + #define UNICAM_PUM_UNPACK6 1
> + #define UNICAM_PUM_UNPACK7 2
> + #define UNICAM_PUM_UNPACK8 3
> + #define UNICAM_PUM_UNPACK10 4
> + #define UNICAM_PUM_UNPACK12 5
> + #define UNICAM_PUM_UNPACK14 6
> + #define UNICAM_PUM_UNPACK16 7
> +#define UNICAM_DDM_MASK GENMASK(6, 3)
> +#define UNICAM_PPM_MASK GENMASK(9, 7)
> + /* Packing modes */
> + #define UNICAM_PPM_NONE 0
> + #define UNICAM_PPM_PACK8 1
> + #define UNICAM_PPM_PACK10 2
> + #define UNICAM_PPM_PACK12 3
> + #define UNICAM_PPM_PACK14 4
> + #define UNICAM_PPM_PACK16 5

I'd drop the leading tab.

> +#define UNICAM_DEM_MASK GENMASK(11, 10)
> +#define UNICAM_DEBL_MASK GENMASK(14, 12)
> +#define UNICAM_ICM_MASK GENMASK(16, 15)
> +#define UNICAM_IDM_MASK GENMASK(17, 17)
> +
> +/* UNICAM_ICC Register */
> +#define UNICAM_ICFL_MASK GENMASK(4, 0)
> +#define UNICAM_ICFH_MASK GENMASK(9, 5)
> +#define UNICAM_ICST_MASK GENMASK(12, 10)
> +#define UNICAM_ICLT_MASK GENMASK(15, 13)
> +#define UNICAM_ICLL_MASK GENMASK(31, 16)
> +
> +/* UNICAM_DCS Register */
> +#define UNICAM_DIE BIT(0)
> +#define UNICAM_DIM BIT(1)
> +#define UNICAM_DBOB BIT(3)
> +#define UNICAM_FDE BIT(4)
> +#define UNICAM_LDP BIT(5)
> +#define UNICAM_EDL_MASK GENMASK(15, 8)
> +
> +/* UNICAM_DBCTL Register */
> +#define UNICAM_DBEN BIT(0)
> +#define UNICAM_BUF0_IE BIT(1)
> +#define UNICAM_BUF1_IE BIT(2)
> +
> +/* UNICAM_CMP[0,1] register */
> +#define UNICAM_PCE BIT(31)
> +#define UNICAM_GI BIT(9)
> +#define UNICAM_CPH BIT(8)
> +#define UNICAM_PCVC_MASK GENMASK(7, 6)
> +#define UNICAM_PCDT_MASK GENMASK(5, 0)
> +
> +/* UNICAM_MISC register */
> +#define UNICAM_FL0 BIT(6)
> +#define UNICAM_FL1 BIT(9)
> +
> +#endif

--
Regards,

Laurent Pinchart

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