Re: [PATCH v5 04/11] media: bcm2835-unicam: Add support for CCP2/CSI2 camera interface

Stefan Wahren
2022-02-20T10:02:42Z

Hi Jean-Michel,

here are just some nits

Am 08.02.22 um 16:50 schrieb Jean-Michel Hautbois:
> 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@raspberrypi.com>
> Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
>
> ---
> v4:
> - Add the vendor prefox for DT name
> - Use the reg-names in DT parsing
> - Remove MAINTAINERS entry
>
> v3 main changes:
> - Change code organization
> - Remove unused variables
> - Correct the fmt_meta functions
> - Rewrite the start/stop streaming
> - You can now start the image node alone, but not the metadata one
> - The buffers are allocated per-node
> - only the required stream is started, if the route exists and is
> enabled
> - Prefix the macros with UNICAM_ to not have too generic names
> - Drop colorspace support
> -> This is causing issues in the try-fmt v4l2-compliance test
> test VIDIOC_G_FMT: OK
> fail: v4l2-test-formats.cpp(363): colorspace >= 0xff
> fail: v4l2-test-formats.cpp(465): testColorspace(!node->is_io_mc, pix.pixelformat, pix.colorspace, pix.ycbcr_enc, pix.quantization)
> test VIDIOC_TRY_FMT: FAIL
> fail: v4l2-test-formats.cpp(363): colorspace >= 0xff
> fail: v4l2-test-formats.cpp(465): testColorspace(!node->is_io_mc, pix.pixelformat, pix.colorspace, pix.ycbcr_enc, pix.quantization)
> test VIDIOC_S_FMT: FAIL
>
> v2: Remove the unicam_{info,debug,error} macros and use
> dev_dbg/dev_err instead.
> ---
> drivers/media/platform/Kconfig | 1 +
> drivers/media/platform/Makefile | 2 +
> drivers/media/platform/bcm2835/Kconfig | 21 +
> drivers/media/platform/bcm2835/Makefile | 3 +
> .../platform/bcm2835/bcm2835-unicam-regs.h | 253 ++
> .../media/platform/bcm2835/bcm2835-unicam.c | 2570 +++++++++++++++++
> 6 files changed, 2850 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-regs.h
> create mode 100644 drivers/media/platform/bcm2835/bcm2835-unicam.c
>
> 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 28eb4aadbf45..18894fc586aa 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -86,6 +86,8 @@ obj-$(CONFIG_VIDEO_QCOM_CAMSS) += qcom/camss/
>
> obj-$(CONFIG_VIDEO_QCOM_VENUS) += qcom/venus/
>
> +obj-$(CONFIG_VIDEO_BCM2835_UNICAM) += bcm2835/
> +
> obj-y += sunxi/
>
> obj-$(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..1691541da905
> --- /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 ARCH_BCM2835 || COMPILE_TEST
> + depends on VIDEO_V4L2
> + select MEDIA_CONTROLLER
> + select VIDEO_V4L2_SUBDEV_API
> + select V4L2_FWNODE
> + select VIDEOBUF2_DMA_CONTIG
> + 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.
> +
> + 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-regs.h b/drivers/media/platform/bcm2835/bcm2835-unicam-regs.h
> new file mode 100644
> index 000000000000..b8d297076a02
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/bcm2835-unicam-regs.h
> @@ -0,0 +1,253 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +/*
> + * Copyright (C) 2017-2020 Raspberry Pi Trading.
> + * Dave Stevenson <dave.stevenson@raspberrypi.com>
> + */
> +
> +#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
> +
> +/*
> + * 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)
> +
> +/* 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)
> +
> +/* 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
> +#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
> diff --git a/drivers/media/platform/bcm2835/bcm2835-unicam.c b/drivers/media/platform/bcm2835/bcm2835-unicam.c
> new file mode 100644
> index 000000000000..470e691637c7
> --- /dev/null
> +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
> @@ -0,0 +1,2570 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * BCM283x / BCM271x Unicam Capture Driver
> + *
> + * Copyright (C) 2017-2020 - Raspberry Pi (Trading) Ltd.
> + *
> + * Dave Stevenson <dave.stevenson@raspberrypi.com>
> + *
> + * Based on TI am437x driver by
> + * Benoit Parrot <bparrot@ti.com>
> + * Lad, Prabhakar <prabhakar.csengg@gmail.com>
> + *
> + * and TI CAL camera interface driver by
> + * Benoit Parrot <bparrot@ti.com>
> + *
> + *
> + * 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-async.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/v4l2-mc.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include "bcm2835-unicam-regs.h"
> +
> +#define UNICAM_MODULE_NAME "unicam"
> +
...
> +
> +static int unicam_sd_enable_streams(struct v4l2_subdev *sd, u32 pad,
> + u64 streams_mask)
> +{
> + struct unicam_device *unicam = sd_to_unicam_device(sd);
> + struct v4l2_subdev_state *state;
> + u32 other_pad, other_stream;
> + int ret;
> +
> + if (WARN_ON(streams_mask != 1))
> + return -EINVAL;
Can we print some error message additionally to the stacktrace?
> +
> + state = v4l2_subdev_lock_active_state(sd);
> +
> + ret = v4l2_subdev_routing_find_opposite_end(&state->routing, pad, 0,
> + &other_pad, &other_stream);
> +
> + v4l2_subdev_unlock_state(state);
> +
> + if (ret)
> + return ret;
> +
> + unicam->sequence = 0;
> +
> + dev_dbg(unicam->dev, "Running with %u data lanes\n",
> + unicam->active_data_lanes);
> +
> + ret = clk_set_min_rate(unicam->vpu_clock, UNICAM_MIN_VPU_CLOCK_RATE);
> + if (ret) {
> + dev_err(unicam->dev, "failed to set up VPU clock\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(unicam->vpu_clock);
> + if (ret) {
> + dev_err(unicam->dev, "Failed to enable VPU clock: %d\n", ret);
> + goto err_vpu_clock;
> + }
> +
> + ret = clk_set_rate(unicam->clock, 100 * 1000 * 1000);
> + if (ret) {
> + dev_err(unicam->dev, "failed to set up CSI clock\n");
> + goto err_vpu_prepare;
> + }
> +
> + ret = clk_prepare_enable(unicam->clock);
> + if (ret) {
> + dev_err(unicam->dev, "Failed to enable CSI clock: %d\n", ret);
> + goto err_vpu_prepare;
> + }
> +
> + ret = v4l2_subdev_call(unicam->sensor.subdev, video, enable_streams,
> + unicam->sensor.pad->index, BIT(other_stream));
> +
> + if (ret && ret == -ENOIOCTLCMD)
> + ret = v4l2_subdev_call(unicam->sensor.subdev, video, s_stream, 1);
> +
> + if (ret) {
> + dev_err(unicam->dev, "stream on failed in subdev\n");
> + goto err_enable_stream;
> + }
> +
> + unicam->subdev.streaming = true;
> +
> + return 0;
> +
> +err_enable_stream:
> + clk_disable_unprepare(unicam->clock);
> +err_vpu_prepare:
> + clk_disable_unprepare(unicam->vpu_clock);
> +err_vpu_clock:
> + if (clk_set_min_rate(unicam->vpu_clock, 0))
> + dev_err(unicam->dev, "failed to reset the VPU clock\n");
> + return ret;
> +}
> +
> +static int unicam_sd_disable_streams(struct v4l2_subdev *sd, u32 pad,
> + u64 streams_mask)
> +{
> + struct unicam_device *unicam = sd_to_unicam_device(sd);
> + struct v4l2_subdev_state *state;
> + u32 other_pad, other_stream;
> + int ret;
> +
> + if (WARN_ON(streams_mask != 1))
> + return -EINVAL;
Can we print some error message additionally to the stacktrace?
> +
> + state = v4l2_subdev_lock_active_state(sd);
> +
> + ret = v4l2_subdev_routing_find_opposite_end(&state->routing, pad, 0,
> + &other_pad, &other_stream);
> +
> + v4l2_subdev_unlock_state(state);
> +
> + if (ret) {
> + dev_err(unicam->dev, "disable streams failed: %d\n", ret);
> + return ret;
> + }
> +
> + ret = v4l2_subdev_call(unicam->sensor.subdev, video, disable_streams,
> + unicam->sensor.pad->index, BIT(other_stream));
> +
> + if (ret && ret == -ENOIOCTLCMD) {
> + /* The sensor does not support disable streams. */
> + if (unicam->node[UNICAM_IMAGE_NODE].streaming &&
> + other_pad == unicam->node[UNICAM_METADATA_NODE].pad.index) {
> + /* We won't stop the sensor yet. */
> + unicam->subdev.streaming = false;
> + return 0;
> + }
> + /* There is no more the metadata node, we can stop. */
> + ret = v4l2_subdev_call(unicam->sensor.subdev, video, s_stream, 0);
> + }
> +
> + clk_disable_unprepare(unicam->clock);
> + if (clk_set_min_rate(unicam->vpu_clock, 0))
> + dev_err(unicam->dev, "failed to reset the VPU clock\n");
> + clk_disable_unprepare(unicam->vpu_clock);
> +
> + unicam->subdev.streaming = false;
> +
> + return 0;
> +}
> +
> +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 *sink_format, *source_format;
> + const struct unicam_fmt *fmtinfo;
> + int ret = 0;
> +
> + if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE && unicam->subdev.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);
> +
> + fmtinfo = unicam_find_format_by_code(format->format.code, format->pad);
> + if (!fmtinfo)
> + fmtinfo = &unicam_image_formats[0];
> +
> + if (format->pad == UNICAM_SD_PAD_SOURCE_IMAGE) {
> + format->format.width = clamp_t(unsigned int,
> + format->format.width,
> + UNICAM_MIN_WIDTH,
> + UNICAM_MAX_WIDTH);
> + format->format.height = clamp_t(unsigned int,
> + format->format.height,
> + UNICAM_MIN_HEIGHT,
> + UNICAM_MAX_HEIGHT);
> + }
> + format->format.field = V4L2_FIELD_NONE;
> +
> + v4l2_subdev_lock_state(state);
> +
> + 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;
> + u32 pad, stream;
> + int ret = -EINVAL;
> +
> + if (fse->index > 0)
> + return ret;
> +
> + v4l2_subdev_lock_state(state);
> +
> + ret = v4l2_subdev_routing_find_opposite_end(&state->routing, fse->pad,
> + fse->stream, &pad,
> + &stream);
> + if (ret)
> + goto out;
> +
> + if (unicam_sd_pad_is_source(fse->pad)) {
> + /* No transcoding, source and sink formats must match. */
> + struct v4l2_mbus_framefmt *fmt;
> +
> + fmt = v4l2_state_get_stream_format(state, pad, stream);
> + if (!fmt)
> + goto out;
> +
> + if (fse->code != fmt->code)
> + goto out;
> +
> + fse->min_width = fmt->width;
> + fse->max_width = fmt->width;
> + fse->min_height = fmt->height;
> + fse->max_height = fmt->height;
> + } else {
> + fmtinfo = unicam_find_format_by_code(fse->code, pad);
> + if (!fmtinfo)
> + goto out;
> +
> + fse->min_width = UNICAM_MIN_WIDTH;
> + fse->max_width = UNICAM_MAX_WIDTH;
> + fse->min_height = UNICAM_MIN_HEIGHT;
> + fse->max_height = UNICAM_MAX_HEIGHT;
> + }
> +
> +out:
> + v4l2_subdev_unlock_state(state);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_subdev_video_ops unicam_subdev_video_ops = {
> + .enable_streams = unicam_sd_enable_streams,
> + .disable_streams = unicam_sd_disable_streams,
> +};
> +
> +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 const struct media_entity_operations unicam_subdev_media_ops = {
> + .link_validate = v4l2_subdev_link_validate,
> + .has_route = v4l2_subdev_has_route,
> +};
> +
> +static int unicam_init_and_register_subdev(struct unicam_device *unicam)
> +{
> + struct v4l2_subdev *sd = &unicam->subdev.sd;
> + int ret;
> +
> + v4l2_subdev_init(sd, &unicam_subdev_ops);
> + v4l2_set_subdevdata(sd, unicam);
> + unicam->subdev.sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> + unicam->subdev.sd.entity.ops = &unicam_subdev_media_ops;
> + unicam->subdev.sd.dev = unicam->dev;
> + unicam->subdev.sd.owner = THIS_MODULE;
> + unicam->subdev.sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_MULTIPLEXED;
> + snprintf(unicam->subdev.sd.name, sizeof(unicam->subdev.sd.name), "unicam-subdev");
> +
> + unicam->subdev.pads[UNICAM_SD_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> +
> + unicam->subdev.pads[UNICAM_SD_PAD_SOURCE_IMAGE].flags = MEDIA_PAD_FL_SOURCE;
> + unicam->subdev.pads[UNICAM_SD_PAD_SOURCE_METADATA].flags = MEDIA_PAD_FL_SOURCE;
> +
> + ret = media_entity_pads_init(&sd->entity,
> + ARRAY_SIZE(unicam->subdev.pads), unicam->subdev.pads);
> + if (ret) {
> + dev_err(unicam->dev, "Could not init media entity");
> + return ret;
> + }
> +
> + ret = v4l2_subdev_init_finalize(sd);
> + if (ret) {
> + dev_err(unicam->dev, "Could not finalize init for subdev");
> + return ret;
> + }
> +
> + return v4l2_device_register_subdev(&unicam->v4l2_dev, sd);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Videobuf2 Queue 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 *unicam = 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_dbg(unicam->dev, "sizes[0] %i < size %u\n", sizes[0],
> + size);
> + 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 *unicam = node->dev;
> + struct unicam_buffer *buf = to_unicam_buffer(vb);
> + unsigned long size;
> +
> + if (WARN_ON(!node->fmt))
> + return -EINVAL;
Can we print some error message additionally to the stacktrace?
> +
> + 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_dbg(unicam->dev, "data will not fit into plane (%lu < %lu)\n",
> + vb2_plane_size(vb, 0), size);
> + return -EINVAL;
> + }
> +
> + vb2_set_plane_payload(&buf->vb.vb2_buf, 0, size);
> + return 0;
> +}
> +
...
> +
> +static int unicam_connect_of_subdevs(struct unicam_device *unicam)
> +{
> + struct v4l2_fwnode_endpoint ep = { };
> + struct fwnode_handle *ep_handle;
> + struct v4l2_async_subdev *asd;
> + unsigned int lane;
> + int ret = -EINVAL;
> +
> + if (of_property_read_u32(unicam->dev->of_node, "brcm,num-data-lanes",
> + &unicam->max_data_lanes) < 0) {
> + dev_err(unicam->dev, "DT property %s not set\n",
> + "brcm,num-data-lanes");
> + return -EINVAL;
> + }
> +
> + /* Get the local endpoint and remote device. */
> + ep_handle = fwnode_graph_get_endpoint_by_id(dev_fwnode(unicam->dev),
> + 0, 0,
> + FWNODE_GRAPH_ENDPOINT_NEXT);
> + if (!ep_handle) {
> + dev_err(unicam->dev, "No endpoint\n");
> + return -ENODEV;
> + }
> +
> + /* Parse the local endpoint and validate its configuration. */
> + if (v4l2_fwnode_endpoint_alloc_parse(ep_handle, &ep)) {
> + dev_err(unicam->dev, "could not parse endpoint\n");
> + goto cleanup_exit;
> + }
> +
> + dev_dbg(unicam->dev, "parsed local endpoint, bus_type %u\n",
> + ep.bus_type);
> +
> + unicam->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(unicam->dev, "%u data lanes not supported\n",
> + 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(unicam->dev, "data lanes reordering not supported\n");
> + goto cleanup_exit;
> + }
> + }
> +
> + if (ep.bus.mipi_csi2.num_data_lanes > unicam->max_data_lanes) {
> + dev_err(unicam->dev, "endpoint requires %u data lanes when %u are supported\n",
> + ep.bus.mipi_csi2.num_data_lanes,
> + unicam->max_data_lanes);
> + }
> +
> + unicam->active_data_lanes = ep.bus.mipi_csi2.num_data_lanes;
> + unicam->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(unicam->dev, "unsupported lanes configuration\n");
> + goto cleanup_exit;
> + }
> +
> + unicam->max_data_lanes = 1;
> + unicam->active_data_lanes = 1;
> + unicam->bus_flags = ep.bus.mipi_csi1.strobe;
> + break;
> +
> + default:
> + /* Unsupported bus type */
> + dev_err(unicam->dev, "unsupported bus type %u\n",
> + ep.bus_type);
> + goto cleanup_exit;
> + }
> +
> + dev_dbg(unicam->dev, "%s bus, %u data lanes, flags=0x%08x\n",
> + unicam->bus_type == V4L2_MBUS_CSI2_DPHY ? "CSI-2" : "CCP2",
> + unicam->active_data_lanes, unicam->bus_flags);
> +
> + /* Initialize and register the async notifier. */
> + v4l2_async_nf_init(&unicam->notifier);
> +
> + asd = v4l2_async_nf_add_fwnode_remote(&unicam->notifier, ep_handle,
> + struct v4l2_async_subdev);
> +
> + fwnode_handle_put(ep_handle);
> + ep_handle = NULL;
> +
> + if (IS_ERR(asd)) {
please provide a log entry here
> + ret = PTR_ERR(asd);
> + goto cleanup_exit;
> + }
> +
> + unicam->notifier.ops = &unicam_async_ops;
> +
> + ret = v4l2_async_nf_register(&unicam->v4l2_dev, &unicam->notifier);
> + if (ret) {
> + dev_err(unicam->dev, "Error registering device notifier: %d\n", ret);
> + goto cleanup_exit;
> + }
> +
> + return 0;
> +
> +cleanup_exit:
> + v4l2_fwnode_endpoint_free(&ep);
> + fwnode_handle_put(ep_handle);
> +
> + return ret;
> +}
> +
> +static int unicam_media_dev_init(struct unicam_device *unicam)
> +{
> + int ret = 0;
no need to init ret here
> +
> + unicam->mdev.dev = unicam->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(unicam->dev));
> + unicam->mdev.hw_revision = 0;
> +
> + media_device_init(&unicam->mdev);
> +
> + unicam->v4l2_dev.mdev = &unicam->mdev;
> +
> + ret = v4l2_device_register(unicam->dev, &unicam->v4l2_dev);
> + if (ret < 0) {
> + dev_err(unicam->dev,
> + "Unable to register v4l2 device\n");
> + return ret;
> + }
> +
> + ret = media_device_register(&unicam->mdev);
> + if (ret < 0) {
> + dev_err(unicam->dev,
> + "Unable to register media-controller device\n");
> + goto err_v4l2_unregister;
> + }
> +
> + return 0;
> +
> +err_v4l2_unregister:
> + v4l2_device_unregister(&unicam->v4l2_dev);
> + return ret;
> +}
> +
> +static int unicam_probe(struct platform_device *pdev)
> +{
> + struct unicam_device *unicam;
> + int ret = 0;
> +
> + unicam = kzalloc(sizeof(*unicam), GFP_KERNEL);
> + if (!unicam)
> + return -ENOMEM;
> +
> + kref_init(&unicam->kref);
> + unicam->dev = &pdev->dev;
> + /* set the driver data in platform device */
> + platform_set_drvdata(pdev, unicam);
> +
> + unicam->base = devm_platform_ioremap_resource_byname(pdev, "unicam");
> + if (IS_ERR(unicam->base)) {
> + ret = PTR_ERR(unicam->base);
> + goto err_unicam_put;
> + }
> +
> + unicam->clk_gate_base = devm_platform_ioremap_resource_byname(pdev, "cmi");
> + if (IS_ERR(unicam->clk_gate_base)) {
> + 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->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->dev, "Failed to get vpu clock\n");
> + ret = PTR_ERR(unicam->vpu_clock);
> + goto err_unicam_put;
> + }
> +
> + 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 = unicam_media_dev_init(unicam);
> + if (ret) {
> + dev_err(unicam->dev,
> + "Unable to initialize media device\n");
> + goto err_unicam_put;
> + }
> +
> + ret = unicam_init_and_register_subdev(unicam);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to register internal subdev\n");

please drop this unnecessary log entry, because the called function
already provide more helpful log entries.

Best regards

> + goto err_media_unregister;
> + }
> +
> + ret = unicam_connect_of_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->subdev.sd);
> +err_media_unregister:
> + media_device_unregister(&unicam->mdev);
> +err_unicam_put:
> + unicam_put(unicam);
> +
> + return ret;
> +}
> +
> +static int unicam_remove(struct platform_device *pdev)
> +{
> + struct unicam_device *unicam = platform_get_drvdata(pdev);
> +
> + unicam_unregister_nodes(unicam);
> + v4l2_device_unregister(&unicam->v4l2_dev);
> + media_device_unregister(&unicam->mdev);
> + v4l2_async_nf_unregister(&unicam->notifier);
> + unicam_put(unicam);
> +
> + 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@raspberrypi.com>");
> +MODULE_DESCRIPTION("BCM2835 Unicam driver");
> +MODULE_LICENSE("GPL");