RE: [PATCH v13 2/2] media: v4l: xilinx: Add Xilinx MIPI CSI-2 Rx Subsystem driver

[Vishal Sagar <vsagar@xilinx.com>]

Hi Laurent,

Thanks for reviewing this patch.

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Sent: Sunday, May 24, 2020 7:57 AM
> To: Vishal Sagar <vsagar@xilinx.com>
> Cc: Hyun Kwon <hyunk@xilinx.com>; mchehab@kernel.org;
> robh+dt@kernel.org; mark.rutland@arm.com; Michal Simek
> <michals@xilinx.com>; linux-media@vger.kernel.org;
> devicetree@vger.kernel.org; hans.verkuil@cisco.com; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Dinesh Kumar
> <dineshk@xilinx.com>; Sandip Kothari <sandipk@xilinx.com>; Luca Ceresoli
> <luca@lucaceresoli.net>; Jacopo Mondi <jacopo@jmondi.org>; Hyun Kwon
> <hyunk@xilinx.com>
> Subject: Re: [PATCH v13 2/2] media: v4l: xilinx: Add Xilinx MIPI CSI-2 Rx
> Subsystem driver
> 
> Hi Vishal,
> 
> Thank you for the patch.
> 
> On Tue, May 12, 2020 at 08:49:47PM +0530, Vishal Sagar wrote:
> > The Xilinx MIPI CSI-2 Rx Subsystem soft IP is used to capture images
> > from MIPI CSI-2 camera sensors and output AXI4-Stream video data ready
> > for image processing. Please refer to PG232 for details.
> >
> > The CSI2 Rx controller filters out all packets except for the packets
> > with data type fixed in hardware. RAW8 packets are always allowed to
> > pass through.
> >
> > It is also used to setup and handle interrupts and enable the core. It
> > logs all the events in respective counters between streaming on and off.
> >
> > The driver supports only the video format bridge enabled configuration.
> > Some data types like YUV 422 10bpc, RAW16, RAW20 are supported when
> > the CSI v2.0 feature is enabled in design. When the VCX feature is
> > enabled, the maximum number of virtual channels becomes 16 from 4.
> >
> > Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
> > Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > v13
> > - Based on Laurent's suggestions
> > - Removed unnecessary debug statement for vep
> > - Added TODO for clock to enable disable at streamon/off
> > - Fix for index to start from 0 for get_nth_mbus_format
> > - Removed macro XCSI_TIMEOUT_VAL
> > - Remove ndelay from hard reset
> > - Remove hard reset from irq handler
> > - Fix short packet fifo clear
> > - Add TODO for v4l2_subdev_notify for SLBF error
> > - Fix the enable condition in s_stream
> > - Fix condition in xcsi2rxss_set_format
> > - Fix enum_mbus_code for double enumeration of RAW8 Data type
> > - Removed core struct
> > - Added reviewed by Laurent
> >
> > v12
> > - Changes done as suggested by Laurent Pinchart and Luca Ceresoli
> > - Removed unused macros
> > - No local storage of supported formats
> > - Dropped init mbus fmts and removed xcsi2rxss_init_mbus_fmts()
> > - XCSI_GET_BITSET_STR removed
> > - Add data type and mbus LUT
> >   - Added xcsi2rxss_get_nth_mbus() and xcsi2rxss_get_dt()
> > - Replaced all core->dev with dev in dev_dbg() and related debug
> > prints
> > - Replaced xcsi2rxss_log_ipconfig() with single line
> > - Removed small functions to enable/disable interrupts and core
> > - Now save remote subdev in state struct before streaming on
> > - Made xcsi2rxss_reset as soft_reset()
> > - Added hard reset using video-reset gpio
> >   - 2 modes one with delay and another sleep
> > - Instead of reset-gpios it is not video-reset-gpios
> > - In irq handler
> >   - Moved clearing of ISR up
> >   - Dump / empty short packet fifo
> >   - Irq handler is now threaded
> > - Added init_cfg pad ops and removed open()
> > - Updated xcsi2rxss_set_format(), xcsi2rxss_enum_mbus_code() to use
> > the dt mbus lut
> > - xcsi2rxss_set_default_format() updated
> > - Moved mutex_init()
> > - Updated graph handling
> > - Removed unnecessary prints
> > - Use devm_platform_ioremap_resource() and platform_get_irq()
> > - Update KConfig description
> >
> > v11
> > - Fixed changes as suggested by Sakari Ailus
> > - Removed VIDEO_XILINX from KConfig
> > - Minor formatting
> > - Start / Stop upstream sub-device in xcsi2rxss_start_stream()
> >   and xcsi2rxss_stop_stream()
> > - Added v4l2_subdev_link_validate_default() in v4l2_subdev_pad_ops()
> > - Use fwnode_graph_get_endpoint_by_id() instead of parsing by self
> > - Set bus type as V4L2_MBUS_CSI2_DPHY in struct v4l2_fwnode_endpoint
> > - Remove num_clks from core. Instead use ARRAY_SIZE()
> > - Fixed SPDX header to GPL-2.0
> > - Update copyright year to 2020
> >
> > v10
> > - Removed all V4L2 controls and events based on Sakari's comments.
> > - Now stop_stream() before toggling rst_gpio
> > - Updated init_mbus() to throw error on array out of bound access
> > - Make events and vcx_events as counters instead of structures
> > - Minor fixes in set_format() enum_mbus_code() as suggested by Sakari
> >
> > v9
> > - Moved all controls and events to xilinx-csi2rxss.h
> > - Updated name and description of controls and events
> > - Get control base address from v4l2-controls.h (0x10c0)
> > - Fix KConfig for dependency on VIDEO_XILINX
> > - Added enum_mbus_code() support
> > - Added default format to be returned on open()
> > - Mark variables are const
> > - Remove references to short packet in comments
> > - Add check for streaming before setting active lanes control
> > - strlcpy -> strscpy
> > - Fix xcsi2rxss_set_format()
> >
> > v8
> > - Use clk_bulk* APIs
> > - Add gpio reset for asserting video_aresetn when stream line buffer
> > occurs
> > - Removed short packet related events and irq handling
> >   - V4L2_EVENT_XLNXCSIRX_SPKT and V4L2_EVENT_XLNXCSIRX_SPKT_OVF
> > removed
> > - Removed frame counter control
> V4L2_CID_XILINX_MIPICSISS_FRAME_COUNTER
> >   and xcsi2rxss_g_volatile_ctrl()
> > - Minor formatting fixes
> >
> > v7
> > - No change
> >
> > v6
> > - No change
> >
> > v5
> > - Removed bayer and updated related parts like set default format based
> >   on Luca Cersoli's comments.
> > - Added correct YUV422 10bpc media bus format
> >
> > v4
> > - Removed irq member from core structure
> > - Consolidated IP config prints in xcsi2rxss_log_ipconfig()
> > - Return -EINVAL in case of invalid ioctl
> > - Code formatting
> > - Added reviewed by Hyun Kwon
> >
> > v3
> > - Fixed comments given by Hyun.
> > - Removed DPHY 200 MHz clock. This will be controlled by DPHY driver
> > - Minor code formatting
> > - en_csi_v20 and vfb members removed from struct and made local to dt
> > parsing
> > - lock description updated
> > - changed to ratelimited type for all dev prints in irq handler
> > - Removed YUV 422 10bpc media format
> >
> > v2
> > - Fixed comments given by Hyun and Sakari.
> > - Made all bitmask using BIT() and GENMASK()
> > - Removed unused definitions
> > - Removed DPHY access. This will be done by separate DPHY PHY driver.
> > - Added support for CSI v2.0 for YUV 422 10bpc, RAW16, RAW20 and extra
> >   virtual channels
> > - Fixed the ports as sink and source
> > - Now use the v4l2fwnode API to get number of data-lanes
> > - Added clock framework support
> > - Removed the close() function
> > - updated the set format function
> > - support only VFB enabled configuration
> >
> >  drivers/media/platform/xilinx/Kconfig         |    7 +
> >  drivers/media/platform/xilinx/Makefile        |    1 +
> >  .../media/platform/xilinx/xilinx-csi2rxss.c   | 1114 +++++++++++++++++
> >  3 files changed, 1122 insertions(+)
> >  create mode 100644 drivers/media/platform/xilinx/xilinx-csi2rxss.c
> >
> > diff --git a/drivers/media/platform/xilinx/Kconfig
> > b/drivers/media/platform/xilinx/Kconfig
> > index 01c96fb66414..44587dccacf1 100644
> > --- a/drivers/media/platform/xilinx/Kconfig
> > +++ b/drivers/media/platform/xilinx/Kconfig
> > @@ -12,6 +12,13 @@ config VIDEO_XILINX
> >
> >  if VIDEO_XILINX
> >
> > +config VIDEO_XILINX_CSI2RXSS
> > +	tristate "Xilinx CSI-2 Rx Subsystem"
> > +	help
> > +	  Driver for Xilinx MIPI CSI-2 Rx Subsystem. This is a V4L sub-device
> > +	  based driver that takes input from CSI-2 Tx source and converts
> > +	  it into an AXI4-Stream.
> > +
> >  config VIDEO_XILINX_TPG
> >  	tristate "Xilinx Video Test Pattern Generator"
> >  	depends on VIDEO_XILINX
> > diff --git a/drivers/media/platform/xilinx/Makefile
> > b/drivers/media/platform/xilinx/Makefile
> > index 4cdc0b1ec7a5..6119a34f3043 100644
> > --- a/drivers/media/platform/xilinx/Makefile
> > +++ b/drivers/media/platform/xilinx/Makefile
> > @@ -3,5 +3,6 @@
> >  xilinx-video-objs += xilinx-dma.o xilinx-vip.o xilinx-vipp.o
> >
> >  obj-$(CONFIG_VIDEO_XILINX) += xilinx-video.o
> > +obj-$(CONFIG_VIDEO_XILINX_CSI2RXSS) += xilinx-csi2rxss.o
> >  obj-$(CONFIG_VIDEO_XILINX_TPG) += xilinx-tpg.o
> >  obj-$(CONFIG_VIDEO_XILINX_VTC) += xilinx-vtc.o diff --git
> > a/drivers/media/platform/xilinx/xilinx-csi2rxss.c
> > b/drivers/media/platform/xilinx/xilinx-csi2rxss.c
> > new file mode 100644
> > index 000000000000..cac08149ae7a
> > --- /dev/null
> > +++ b/drivers/media/platform/xilinx/xilinx-csi2rxss.c
> > @@ -0,0 +1,1114 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Driver for Xilinx MIPI CSI-2 Rx Subsystem
> > + *
> > + * Copyright (C) 2016 - 2020 Xilinx, Inc.
> > + *
> > + * Contacts: Vishal Sagar <vishal.sagar@xilinx.com>
> > + *
> > + */
> > +#include <linux/clk.h>
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/v4l2-subdev.h>
> > +#include <media/media-entity.h>
> > +#include <media/v4l2-common.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-fwnode.h>
> > +#include <media/v4l2-subdev.h>
> > +#include "xilinx-vip.h"
> > +
> > +/* Register register map */
> > +#define XCSI_CCR_OFFSET		0x00
> > +#define XCSI_CCR_SOFTRESET	BIT(1)
> > +#define XCSI_CCR_ENABLE		BIT(0)
> > +
> > +#define XCSI_PCR_OFFSET		0x04
> > +#define XCSI_PCR_MAXLANES_MASK	GENMASK(4, 3)
> > +#define XCSI_PCR_ACTLANES_MASK	GENMASK(1, 0)
> > +
> > +#define XCSI_CSR_OFFSET		0x10
> > +#define XCSI_CSR_PKTCNT		GENMASK(31, 16)
> > +#define XCSI_CSR_SPFIFOFULL	BIT(3)
> > +#define XCSI_CSR_SPFIFONE	BIT(2)
> > +#define XCSI_CSR_SLBF		BIT(1)
> > +#define XCSI_CSR_RIPCD		BIT(0)
> > +
> > +#define XCSI_GIER_OFFSET	0x20
> > +#define XCSI_GIER_GIE		BIT(0)
> > +
> > +#define XCSI_ISR_OFFSET		0x24
> > +#define XCSI_IER_OFFSET		0x28
> > +
> > +#define XCSI_ISR_FR		BIT(31)
> > +#define XCSI_ISR_VCXFE		BIT(30)
> > +#define XCSI_ISR_WCC		BIT(22)
> > +#define XCSI_ISR_ILC		BIT(21)
> > +#define XCSI_ISR_SPFIFOF	BIT(20)
> > +#define XCSI_ISR_SPFIFONE	BIT(19)
> > +#define XCSI_ISR_SLBF		BIT(18)
> > +#define XCSI_ISR_STOP		BIT(17)
> > +#define XCSI_ISR_SOTERR		BIT(13)
> > +#define XCSI_ISR_SOTSYNCERR	BIT(12)
> > +#define XCSI_ISR_ECC2BERR	BIT(11)
> > +#define XCSI_ISR_ECC1BERR	BIT(10)
> > +#define XCSI_ISR_CRCERR		BIT(9)
> > +#define XCSI_ISR_DATAIDERR	BIT(8)
> > +#define XCSI_ISR_VC3FSYNCERR	BIT(7)
> > +#define XCSI_ISR_VC3FLVLERR	BIT(6)
> > +#define XCSI_ISR_VC2FSYNCERR	BIT(5)
> > +#define XCSI_ISR_VC2FLVLERR	BIT(4)
> > +#define XCSI_ISR_VC1FSYNCERR	BIT(3)
> > +#define XCSI_ISR_VC1FLVLERR	BIT(2)
> > +#define XCSI_ISR_VC0FSYNCERR	BIT(1)
> > +#define XCSI_ISR_VC0FLVLERR	BIT(0)
> > +
> > +#define XCSI_ISR_ALLINTR_MASK	(0xc07e3fff)
> > +
> > +/*
> > + * Removed VCXFE mask as it doesn't exist in IER
> > + * Removed STOP state irq as this will keep driver in irq handler
> > +only  */
> > +#define XCSI_IER_INTR_MASK	(XCSI_ISR_ALLINTR_MASK &\
> > +				 ~(XCSI_ISR_STOP | XCSI_ISR_VCXFE))
> > +
> > +#define XCSI_SPKTR_OFFSET	0x30
> > +#define XCSI_SPKTR_DATA		GENMASK(23, 8)
> > +#define XCSI_SPKTR_VC		GENMASK(7, 6)
> > +#define XCSI_SPKTR_DT		GENMASK(5, 0)
> > +#define XCSI_SPKT_FIFO_DEPTH	31
> > +
> > +#define XCSI_VCXR_OFFSET	0x34
> > +#define XCSI_VCXR_VCERR		GENMASK(23, 0)
> > +#define XCSI_VCXR_FSYNCERR	BIT(1)
> > +#define XCSI_VCXR_FLVLERR	BIT(0)
> > +
> > +#define XCSI_CLKINFR_OFFSET	0x3C
> > +#define XCSI_CLKINFR_STOP	BIT(1)
> > +
> > +#define XCSI_DLXINFR_OFFSET	0x40
> > +#define XCSI_DLXINFR_STOP	BIT(5)
> > +#define XCSI_DLXINFR_SOTERR	BIT(1)
> > +#define XCSI_DLXINFR_SOTSYNCERR	BIT(0)
> > +#define XCSI_MAXDL_COUNT	0x4
> > +
> > +#define XCSI_VCXINF1R_OFFSET		0x60
> > +#define XCSI_VCXINF1R_LINECOUNT		GENMASK(31, 16)
> > +#define XCSI_VCXINF1R_LINECOUNT_SHIFT	16
> > +#define XCSI_VCXINF1R_BYTECOUNT		GENMASK(15, 0)
> > +
> > +#define XCSI_VCXINF2R_OFFSET	0x64
> > +#define XCSI_VCXINF2R_DT	GENMASK(5, 0)
> > +#define XCSI_MAXVCX_COUNT	16
> > +
> > +/*
> > + * Sink pad connected to sensor source pad.
> > + * Source pad connected to next module like demosaic.
> > + */
> > +#define XCSI_MEDIA_PADS		2
> > +#define XCSI_DEFAULT_WIDTH	1920
> > +#define XCSI_DEFAULT_HEIGHT	1080
> > +
> > +/* MIPI CSI-2 Data Types from spec */
> > +#define XCSI_DT_YUV4228B	0x1e
> > +#define XCSI_DT_YUV42210B	0x1f
> > +#define XCSI_DT_RGB444		0x20
> > +#define XCSI_DT_RGB555		0x21
> > +#define XCSI_DT_RGB565		0x22
> > +#define XCSI_DT_RGB666		0x23
> > +#define XCSI_DT_RGB888		0x24
> > +#define XCSI_DT_RAW6		0x28
> > +#define XCSI_DT_RAW7		0x29
> > +#define XCSI_DT_RAW8		0x2a
> > +#define XCSI_DT_RAW10		0x2b
> > +#define XCSI_DT_RAW12		0x2c
> > +#define XCSI_DT_RAW14		0x2d
> > +#define XCSI_DT_RAW16		0x2e
> > +#define XCSI_DT_RAW20		0x2f
> > +
> > +#define XCSI_VCX_START		4
> > +#define XCSI_MAX_VC		4
> > +#define XCSI_MAX_VCX		16
> > +
> > +#define XCSI_NEXTREG_OFFSET	4
> > +
> > +/* There are 2 events frame sync and frame level error per VC */
> > +#define XCSI_VCX_NUM_EVENTS	((XCSI_MAX_VCX - XCSI_MAX_VC) * 2)
> > +
> > +/**
> > + * struct xcsi2rxss_event - Event log structure
> > + * @mask: Event mask
> > + * @name: Name of the event
> > + */
> > +struct xcsi2rxss_event {
> > +	u32 mask;
> > +	const char *name;
> > +};
> > +
> > +static const struct xcsi2rxss_event xcsi2rxss_events[] = {
> > +	{ XCSI_ISR_FR, "Frame Received" },
> > +	{ XCSI_ISR_VCXFE, "VCX Frame Errors" },
> > +	{ XCSI_ISR_WCC, "Word Count Errors" },
> > +	{ XCSI_ISR_ILC, "Invalid Lane Count Error" },
> > +	{ XCSI_ISR_SPFIFOF, "Short Packet FIFO OverFlow Error" },
> > +	{ XCSI_ISR_SPFIFONE, "Short Packet FIFO Not Empty" },
> > +	{ XCSI_ISR_SLBF, "Streamline Buffer Full Error" },
> > +	{ XCSI_ISR_STOP, "Lane Stop State" },
> > +	{ XCSI_ISR_SOTERR, "SOT Error" },
> > +	{ XCSI_ISR_SOTSYNCERR, "SOT Sync Error" },
> > +	{ XCSI_ISR_ECC2BERR, "2 Bit ECC Unrecoverable Error" },
> > +	{ XCSI_ISR_ECC1BERR, "1 Bit ECC Recoverable Error" },
> > +	{ XCSI_ISR_CRCERR, "CRC Error" },
> > +	{ XCSI_ISR_DATAIDERR, "Data Id Error" },
> > +	{ XCSI_ISR_VC3FSYNCERR, "Virtual Channel 3 Frame Sync Error" },
> > +	{ XCSI_ISR_VC3FLVLERR, "Virtual Channel 3 Frame Level Error" },
> > +	{ XCSI_ISR_VC2FSYNCERR, "Virtual Channel 2 Frame Sync Error" },
> > +	{ XCSI_ISR_VC2FLVLERR, "Virtual Channel 2 Frame Level Error" },
> > +	{ XCSI_ISR_VC1FSYNCERR, "Virtual Channel 1 Frame Sync Error" },
> > +	{ XCSI_ISR_VC1FLVLERR, "Virtual Channel 1 Frame Level Error" },
> > +	{ XCSI_ISR_VC0FSYNCERR, "Virtual Channel 0 Frame Sync Error" },
> > +	{ XCSI_ISR_VC0FLVLERR, "Virtual Channel 0 Frame Level Error" } };
> > +
> > +#define XCSI_NUM_EVENTS		ARRAY_SIZE(xcsi2rxss_events)
> > +
> > +/*
> > + * This table provides a mapping between CSI-2 Data type
> > + * and media bus formats
> > + */
> > +static const u32 xcsi2dt_mbus_lut[][2] = {
> > +	{ XCSI_DT_YUV4228B, MEDIA_BUS_FMT_UYVY8_1X16 },
> > +	{ XCSI_DT_YUV42210B, MEDIA_BUS_FMT_UYVY10_1X20 },
> > +	{ XCSI_DT_RGB444, 0 },
> > +	{ XCSI_DT_RGB555, 0 },
> > +	{ XCSI_DT_RGB565, 0 },
> > +	{ XCSI_DT_RGB666, 0 },
> > +	{ XCSI_DT_RGB888, MEDIA_BUS_FMT_RBG888_1X24 },
> > +	{ XCSI_DT_RAW6, 0 },
> > +	{ XCSI_DT_RAW7, 0 },
> > +	{ XCSI_DT_RAW8, MEDIA_BUS_FMT_SRGGB8_1X8 },
> > +	{ XCSI_DT_RAW8, MEDIA_BUS_FMT_SBGGR8_1X8 },
> > +	{ XCSI_DT_RAW8, MEDIA_BUS_FMT_SGBRG8_1X8 },
> > +	{ XCSI_DT_RAW8, MEDIA_BUS_FMT_SGRBG8_1X8 },
> > +	{ XCSI_DT_RAW10, MEDIA_BUS_FMT_SRGGB10_1X10 },
> > +	{ XCSI_DT_RAW10, MEDIA_BUS_FMT_SBGGR10_1X10 },
> > +	{ XCSI_DT_RAW10, MEDIA_BUS_FMT_SGBRG10_1X10 },
> > +	{ XCSI_DT_RAW10, MEDIA_BUS_FMT_SGRBG10_1X10 },
> > +	{ XCSI_DT_RAW12, MEDIA_BUS_FMT_SRGGB12_1X12 },
> > +	{ XCSI_DT_RAW12, MEDIA_BUS_FMT_SBGGR12_1X12 },
> > +	{ XCSI_DT_RAW12, MEDIA_BUS_FMT_SGBRG12_1X12 },
> > +	{ XCSI_DT_RAW12, MEDIA_BUS_FMT_SGRBG12_1X12 },
> > +	{ XCSI_DT_RAW16, MEDIA_BUS_FMT_SRGGB16_1X16 },
> > +	{ XCSI_DT_RAW16, MEDIA_BUS_FMT_SBGGR16_1X16 },
> > +	{ XCSI_DT_RAW16, MEDIA_BUS_FMT_SGBRG16_1X16 },
> > +	{ XCSI_DT_RAW16, MEDIA_BUS_FMT_SGRBG16_1X16 },
> > +	{ XCSI_DT_RAW20, 0 },
> > +};
> > +
> > +/**
> > + * struct xcsi2rxss_state - CSI-2 Rx Subsystem device structure
> > + * @subdev: The v4l2 subdev structure
> > + * @format: Active V4L2 formats on each pad
> > + * @default_format: Default V4L2 format
> > + * @events: counter for events
> > + * @vcx_events: counter for vcx_events
> > + * @dev: Platform structure
> > + * @rsubdev: Remote subdev connected to sink pad
> > + * @rst_gpio: reset to video_aresetn
> > + * @clks: array of clocks
> > + * @iomem: Base address of subsystem
> > + * @max_num_lanes: Maximum number of lanes present
> > + * @datatype: Data type filter
> > + * @lock: mutex for accessing this structure
> > + * @pads: media pads
> > + * @streaming: Flag for storing streaming state
> > + * @enable_active_lanes: If number of active lanes can be modified
> > + * @en_vcx: If more than 4 VC are enabled
> > + *
> > + * This structure contains the device driver related parameters  */
> > +struct xcsi2rxss_state {
> > +	struct v4l2_subdev subdev;
> > +	struct v4l2_mbus_framefmt format;
> > +	struct v4l2_mbus_framefmt default_format;
> > +	u32 events[XCSI_NUM_EVENTS];
> > +	u32 vcx_events[XCSI_VCX_NUM_EVENTS];
> > +	struct device *dev;
> > +	struct v4l2_subdev *rsubdev;
> > +	struct gpio_desc *rst_gpio;
> > +	struct clk_bulk_data *clks;
> > +	void __iomem *iomem;
> > +	u32 max_num_lanes;
> > +	u32 datatype;
> > +	/* used to protect access to this struct */
> > +	struct mutex lock;
> > +	struct media_pad pads[XCSI_MEDIA_PADS];
> > +	bool streaming;
> > +	bool enable_active_lanes;
> > +	bool en_vcx;
> > +};
> > +
> > +static const struct clk_bulk_data xcsi2rxss_clks[] = {
> > +	{ .id = "lite_aclk" },
> > +	{ .id = "video_aclk" },
> > +};
> > +
> > +static inline struct xcsi2rxss_state * to_xcsi2rxssstate(struct
> > +v4l2_subdev *subdev) {
> > +	return container_of(subdev, struct xcsi2rxss_state, subdev); }
> > +
> > +/*
> > + * Register related operations
> > + */
> > +static inline u32 xcsi2rxss_read(struct xcsi2rxss_state *xcsi2rxss,
> > +u32 addr) {
> > +	return ioread32(xcsi2rxss->iomem + addr); }
> > +
> > +static inline void xcsi2rxss_write(struct xcsi2rxss_state *xcsi2rxss, u32 addr,
> > +				   u32 value)
> > +{
> > +	iowrite32(value, xcsi2rxss->iomem + addr); }
> > +
> > +static inline void xcsi2rxss_clr(struct xcsi2rxss_state *xcsi2rxss, u32 addr,
> > +				 u32 clr)
> > +{
> > +	xcsi2rxss_write(xcsi2rxss, addr,
> > +			xcsi2rxss_read(xcsi2rxss, addr) & ~clr); }
> > +
> > +static inline void xcsi2rxss_set(struct xcsi2rxss_state *xcsi2rxss, u32 addr,
> > +				 u32 set)
> > +{
> > +	xcsi2rxss_write(xcsi2rxss, addr, xcsi2rxss_read(xcsi2rxss, addr) |
> > +set); }
> > +
> > +/*
> > + * This function returns the nth mbus for a data type.
> > + * In case of error, mbus code returned is 0.
> > + */
> > +static u32 xcsi2rxss_get_nth_mbus(u32 dt, u32 n) {
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(xcsi2dt_mbus_lut); i++) {
> > +		if (xcsi2dt_mbus_lut[i][0] == dt) {
> > +			if (n-- == 0)
> > +				return xcsi2dt_mbus_lut[i][1];
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/* This returns the data type for a media bus format else 0 */ static
> > +u32 xcsi2rxss_get_dt(u32 mbus) {
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(xcsi2dt_mbus_lut); i++) {
> > +		if (xcsi2dt_mbus_lut[i][1] == mbus)
> > +			return xcsi2dt_mbus_lut[i][0];
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * xcsi2rxss_soft_reset - Does a soft reset of the MIPI CSI-2 Rx
> > +Subsystem
> > + * @state: Xilinx CSI-2 Rx Subsystem structure pointer
> > + *
> > + * Core takes less than 100 video clock cycles to reset.
> > + * So a larger timeout value is chosen for margin.
> > + *
> > + * Return: 0 - on success OR -ETIME if reset times out  */ static int
> > +xcsi2rxss_soft_reset(struct xcsi2rxss_state *state) {
> > +	u32 timeout = 1000; /* us */
> > +
> > +	xcsi2rxss_set(state, XCSI_CCR_OFFSET, XCSI_CCR_SOFTRESET);
> > +
> > +	while (xcsi2rxss_read(state, XCSI_CSR_OFFSET) & XCSI_CSR_RIPCD) {
> > +		if (timeout == 0) {
> > +			dev_err(state->dev, "soft reset timed out!\n");
> > +			return -ETIME;
> > +		}
> > +
> > +		timeout--;
> > +		udelay(1);
> > +	}
> > +
> > +	xcsi2rxss_clr(state, XCSI_CCR_OFFSET, XCSI_CCR_SOFTRESET);
> > +	return 0;
> > +}
> > +
> > +static void xcsi2rxss_hard_reset(struct xcsi2rxss_state *state) {
> > +	if (!state->rst_gpio)
> > +		return;
> > +
> > +	/* minimum of 40 dphy_clk_200M cycles */
> > +	gpiod_set_value_cansleep(state->rst_gpio, 1);
> > +	usleep_range(1, 2);
> > +	gpiod_set_value_cansleep(state->rst_gpio, 0); }
> > +
> > +static void xcsi2rxss_reset_event_counters(struct xcsi2rxss_state
> > +*state) {
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < XCSI_NUM_EVENTS; i++)
> > +		state->events[i] = 0;
> > +
> > +	for (i = 0; i < XCSI_VCX_NUM_EVENTS; i++)
> > +		state->vcx_events[i] = 0;
> > +}
> > +
> > +/* Print event counters */
> > +static void xcsi2rxss_log_counters(struct xcsi2rxss_state *state) {
> > +	struct device *dev = state->dev;
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < XCSI_NUM_EVENTS; i++) {
> > +		if (state->events[i] > 0) {
> > +			dev_info(dev, "%s events: %d\n",
> > +				 xcsi2rxss_events[i].name,
> > +				 state->events[i]);
> > +		}
> > +	}
> > +
> > +	if (state->en_vcx) {
> > +		for (i = 0; i < XCSI_VCX_NUM_EVENTS; i++) {
> > +			if (state->vcx_events[i] > 0) {
> > +				dev_info(dev,
> > +					 "VC %d Frame %s err vcx events:
> %d\n",
> > +					 (i / 2) + XCSI_VCX_START,
> > +					 i & 1 ? "Sync" : "Level",
> > +					 state->vcx_events[i]);
> > +			}
> > +		}
> > +	}
> > +}
> > +
> > +/**
> > + * xcsi2rxss_log_status - Logs the status of the CSI-2 Receiver
> > + * @sd: Pointer to V4L2 subdevice structure
> > + *
> > + * This function prints the current status of Xilinx MIPI CSI-2
> > + *
> > + * Return: 0 on success
> > + */
> > +static int xcsi2rxss_log_status(struct v4l2_subdev *sd) {
> > +	struct xcsi2rxss_state *xcsi2rxss = to_xcsi2rxssstate(sd);
> > +	struct device *dev = xcsi2rxss->dev;
> > +	const char *tr = "true";
> > +	const char *fa = "false";
> 
> I didn't notice this in the previous version, but you could just write "true" and
> "false" below. The compiler should perform string de-duplication automatically.
> 

I had this as a macro XCSI_GET_BITSET_STR till v11 and removed in v12
/* Macro to return "true" or "false" string if bit is set */
#define XCSI_GET_BITSET_STR(val, mask)	(val) & (mask) ? "true" : "false"

I will update this to "true" and "false".

> > +	u32 reg, data;
> > +	unsigned int i, max_vc;
> > +
> > +	mutex_lock(&xcsi2rxss->lock);
> > +
> > +	xcsi2rxss_log_counters(xcsi2rxss);
> > +
> > +	dev_info(dev, "***** Core Status *****\n");
> > +	data = xcsi2rxss_read(xcsi2rxss, XCSI_CSR_OFFSET);
> > +	dev_info(dev, "Short Packet FIFO Full = %s\n",
> > +		 data & XCSI_CSR_SPFIFOFULL ? tr : fa);
> > +	dev_info(dev, "Short Packet FIFO Not Empty = %s\n",
> > +		 data & XCSI_CSR_SPFIFONE ? tr : fa);
> > +	dev_info(dev, "Stream line buffer full = %s\n",
> > +		 data & XCSI_CSR_SLBF ? tr : fa);
> > +	dev_info(dev, "Soft reset/Core disable in progress = %s\n",
> > +		 data & XCSI_CSR_RIPCD ? tr : fa);
> > +
> > +	/* Clk & Lane Info  */
> > +	dev_info(dev, "******** Clock Lane Info *********\n");
> > +	data = xcsi2rxss_read(xcsi2rxss, XCSI_CLKINFR_OFFSET);
> > +	dev_info(dev, "Clock Lane in Stop State = %s\n",
> > +		 data & XCSI_CLKINFR_STOP ? tr : fa);
> > +
> > +	dev_info(dev, "******** Data Lane Info *********\n");
> > +	dev_info(dev, "Lane\tSoT Error\tSoT Sync Error\tStop State\n");
> > +	reg = XCSI_DLXINFR_OFFSET;
> > +	for (i = 0; i < XCSI_MAXDL_COUNT; i++) {
> > +		data = xcsi2rxss_read(xcsi2rxss, reg);
> > +
> > +		dev_info(dev, "%d\t%s\t\t%s\t\t%s\n", i,
> > +			 data & XCSI_DLXINFR_SOTERR ? tr : fa,
> > +			 data & XCSI_DLXINFR_SOTSYNCERR ? tr : fa,
> > +			 data & XCSI_DLXINFR_STOP ? tr : fa);
> > +
> > +		reg += XCSI_NEXTREG_OFFSET;
> > +	}
> > +
> > +	/* Virtual Channel Image Information */
> > +	dev_info(dev, "********** Virtual Channel Info ************\n");
> > +	dev_info(dev, "VC\tLine Count\tByte Count\tData Type\n");
> > +	if (xcsi2rxss->en_vcx)
> > +		max_vc = XCSI_MAX_VCX;
> > +	else
> > +		max_vc = XCSI_MAX_VC;
> > +
> > +	reg = XCSI_VCXINF1R_OFFSET;
> > +	for (i = 0; i < max_vc; i++) {
> > +		u32 line_count, byte_count, data_type;
> > +
> > +		/* Get line and byte count from VCXINFR1 Register */
> > +		data = xcsi2rxss_read(xcsi2rxss, reg);
> > +		byte_count = data & XCSI_VCXINF1R_BYTECOUNT;
> > +		line_count = data & XCSI_VCXINF1R_LINECOUNT;
> > +		line_count >>= XCSI_VCXINF1R_LINECOUNT_SHIFT;
> > +
> > +		/* Get data type from VCXINFR2 Register */
> > +		reg += XCSI_NEXTREG_OFFSET;
> > +		data = xcsi2rxss_read(xcsi2rxss, reg);
> > +		data_type = data & XCSI_VCXINF2R_DT;
> > +
> > +		dev_info(dev, "%d\t%d\t\t%d\t\t0x%x\n", i, line_count,
> > +			 byte_count, data_type);
> > +
> > +		/* Move to next pair of VC Info registers */
> > +		reg += XCSI_NEXTREG_OFFSET;
> > +	}
> > +
> > +	mutex_unlock(&xcsi2rxss->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct v4l2_subdev *xcsi2rxss_get_remote_subdev(struct
> > +media_pad *local) {
> > +	struct media_pad *remote;
> > +
> > +	remote = media_entity_remote_pad(local);
> > +	if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
> > +		return NULL;
> > +
> > +	return media_entity_to_v4l2_subdev(remote->entity);
> > +}
> > +
> > +static int xcsi2rxss_start_stream(struct xcsi2rxss_state *state) {
> > +	int ret = 0;
> > +
> > +	/* enable core */
> > +	xcsi2rxss_set(state, XCSI_CCR_OFFSET, XCSI_CCR_ENABLE);
> > +
> > +	ret = xcsi2rxss_soft_reset(state);
> > +	if (ret < 0) {
> > +		state->streaming = false;
> > +		return ret;
> > +	}
> > +
> > +	/* enable interrupts */
> > +	xcsi2rxss_clr(state, XCSI_GIER_OFFSET, XCSI_GIER_GIE);
> > +	xcsi2rxss_write(state, XCSI_IER_OFFSET, XCSI_IER_INTR_MASK);
> > +	xcsi2rxss_set(state, XCSI_GIER_OFFSET, XCSI_GIER_GIE);
> > +
> > +	state->streaming = true;
> > +
> > +	state->rsubdev =
> > +		xcsi2rxss_get_remote_subdev(&state->pads[XVIP_PAD_SINK]);
> > +
> > +	ret = v4l2_subdev_call(state->rsubdev, video, s_stream, 1);
> > +	if (ret) {
> > +		/* disable interrupts */
> > +		xcsi2rxss_clr(state, XCSI_IER_OFFSET, XCSI_IER_INTR_MASK);
> > +		xcsi2rxss_clr(state, XCSI_GIER_OFFSET, XCSI_GIER_GIE);
> > +
> > +		/* disable core */
> > +		xcsi2rxss_clr(state, XCSI_CCR_OFFSET, XCSI_CCR_ENABLE);
> > +		state->streaming = false;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void xcsi2rxss_stop_stream(struct xcsi2rxss_state *state) {
> > +	v4l2_subdev_call(state->rsubdev, video, s_stream, 0);
> > +
> > +	/* disable interrupts */
> > +	xcsi2rxss_clr(state, XCSI_IER_OFFSET, XCSI_IER_INTR_MASK);
> > +	xcsi2rxss_clr(state, XCSI_GIER_OFFSET, XCSI_GIER_GIE);
> > +
> > +	/* disable core */
> > +	xcsi2rxss_clr(state, XCSI_CCR_OFFSET, XCSI_CCR_ENABLE);
> > +	state->streaming = false;
> > +}
> > +
> > +/**
> > + * xcsi2rxss_irq_handler - Interrupt handler for CSI-2
> > + * @irq: IRQ number
> > + * @data: Pointer to device state
> > + *
> > + * In the interrupt handler, a list of event counters are updated for
> > + * corresponding interrupts. This is useful to get status / debug.
> > + *
> > + * Return: IRQ_HANDLED after handling interrupts  */ static
> > +irqreturn_t xcsi2rxss_irq_handler(int irq, void *data) {
> > +	struct xcsi2rxss_state *state = (struct xcsi2rxss_state *)data;
> > +	struct device *dev = state->dev;
> > +	u32 status;
> > +
> > +	status = xcsi2rxss_read(state, XCSI_ISR_OFFSET) &
> XCSI_ISR_ALLINTR_MASK;
> > +	xcsi2rxss_write(state, XCSI_ISR_OFFSET, status);
> > +
> > +	/* Received a short packet */
> > +	if (status & XCSI_ISR_SPFIFONE) {
> > +		u32 count = 0;
> > +
> > +		/*
> > +		 * Drain generic short packet FIFO by reading max 31
> > +		 * (fifo depth) short packets from fifo or till fifo is empty.
> > +		 */
> > +		for (count = 0; count < XCSI_SPKT_FIFO_DEPTH; ++count) {
> > +			u32 spfifostat, spkt;
> > +
> > +			spkt = xcsi2rxss_read(state, XCSI_SPKTR_OFFSET);
> > +			dev_dbg(dev, "Short packet = 0x%08x\n", spkt);
> > +			spfifostat = xcsi2rxss_read(state, XCSI_ISR_OFFSET);
> > +			spfifostat &= XCSI_ISR_SPFIFONE;
> > +			if (!spfifostat)
> > +				break;
> > +			xcsi2rxss_write(state, XCSI_ISR_OFFSET, spfifostat);
> > +		}
> > +	}
> > +
> > +	/* Short packet FIFO overflow */
> > +	if (status & XCSI_ISR_SPFIFOF)
> > +		dev_dbg_ratelimited(dev, "Short packet FIFO overflowed\n");
> > +
> > +	/*
> > +	 * Stream line buffer full
> > +	 * This means there is a backpressure from downstream IP
> > +	 */
> > +	if (status & XCSI_ISR_SLBF) {
> > +		dev_alert_ratelimited(dev, "Stream Line Buffer Full!\n");
> > +
> > +		/* disable interrupts */
> > +		xcsi2rxss_clr(state, XCSI_IER_OFFSET, XCSI_IER_INTR_MASK);
> > +		xcsi2rxss_clr(state, XCSI_GIER_OFFSET, XCSI_GIER_GIE);
> > +
> > +		/* disable core */
> > +		xcsi2rxss_clr(state, XCSI_CCR_OFFSET, XCSI_CCR_ENABLE);
> > +		state->streaming = false;
> 
> If you set streaming to false, a later call to xcsi2rxss_s_stream(0) will consider
> that the stream is already stopped, and skip calling
> xcsi2rxss_stop_stream() and xcsi2rxss_hard_reset(). Now that you have
> dropped the hard reset from the interrupt handler, we need to rely on it being
> called at stream stop time. Should you just drop the line here ?
> 

Yes I can drop the line "state->streaming = false" here in next version.
The comment below should guide the user to stop streaming in stream line buffer full case.

> > +
> > +		/*
> > +		 * The IP needs to be hard reset before it can be used now.
> > +		 * This will be done in streamoff.
> > +		 */
> > +
> > +		/*
> > +		 * TODO: Notify the whole pipeline with v4l2_subdev_notify()
> to
> > +		 * inform userspace.
> > +		 */
> > +	}
> > +
> > +	/* Increment event counters */
> > +	if (status & XCSI_ISR_ALLINTR_MASK) {
> > +		unsigned int i;
> > +
> > +		for (i = 0; i < XCSI_NUM_EVENTS; i++) {
> > +			if (!(status & xcsi2rxss_events[i].mask))
> > +				continue;
> > +			state->events[i]++;
> > +			dev_dbg_ratelimited(dev, "%s: %u\n",
> > +					    xcsi2rxss_events[i].name,
> > +					    state->events[i]);
> > +		}
> > +
> > +		if (status & XCSI_ISR_VCXFE && state->en_vcx) {
> > +			u32 vcxstatus;
> > +
> > +			vcxstatus = xcsi2rxss_read(state, XCSI_VCXR_OFFSET);
> > +			vcxstatus &= XCSI_VCXR_VCERR;
> > +			for (i = 0; i < XCSI_VCX_NUM_EVENTS; i++) {
> > +				if (!(vcxstatus & (1 << i)))
> > +					continue;
> > +				state->vcx_events[i]++;
> > +			}
> > +			xcsi2rxss_write(state, XCSI_VCXR_OFFSET, vcxstatus);
> > +		}
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +/**
> > + * xcsi2rxss_s_stream - It is used to start/stop the streaming.
> > + * @sd: V4L2 Sub device
> > + * @enable: Flag (True / False)
> > + *
> > + * This function controls the start or stop of streaming for the
> > + * Xilinx MIPI CSI-2 Rx Subsystem.
> > + *
> > + * Return: 0 on success, errors otherwise  */ static int
> > +xcsi2rxss_s_stream(struct v4l2_subdev *sd, int enable) {
> > +	struct xcsi2rxss_state *xcsi2rxss = to_xcsi2rxssstate(sd);
> > +	int ret = 0;
> > +
> > +	mutex_lock(&xcsi2rxss->lock);
> > +
> > +	if (enable == xcsi2rxss->streaming)
> > +		goto stream_done;
> > +
> > +	if (enable) {
> > +		xcsi2rxss_reset_event_counters(xcsi2rxss);
> > +		ret = xcsi2rxss_start_stream(xcsi2rxss);
> > +	} else {
> > +		xcsi2rxss_stop_stream(xcsi2rxss);
> > +		xcsi2rxss_hard_reset(xcsi2rxss);
> > +	}
> > +
> > +stream_done:
> > +	mutex_unlock(&xcsi2rxss->lock);
> > +	return ret;
> > +}
> > +
> > +static struct v4l2_mbus_framefmt *
> > +__xcsi2rxss_get_pad_format(struct xcsi2rxss_state *xcsi2rxss,
> > +			   struct v4l2_subdev_pad_config *cfg,
> > +			   unsigned int pad, u32 which)
> > +{
> > +	switch (which) {
> > +	case V4L2_SUBDEV_FORMAT_TRY:
> > +		return v4l2_subdev_get_try_format(&xcsi2rxss->subdev, cfg,
> pad);
> > +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> > +		return &xcsi2rxss->format;
> > +	default:
> > +		return NULL;
> > +	}
> > +}
> > +
> > +/**
> > + * xcsi2rxss_init_cfg - Initialise the pad format config to default
> > + * @sd: Pointer to V4L2 Sub device structure
> > + * @cfg: Pointer to sub device pad information structure
> > + *
> > + * This function is used to initialize the pad format with the
> > +default
> > + * values.
> > + *
> > + * Return: 0 on success
> > + */
> > +static int xcsi2rxss_init_cfg(struct v4l2_subdev *sd,
> > +			      struct v4l2_subdev_pad_config *cfg) {
> > +	struct xcsi2rxss_state *xcsi2rxss = to_xcsi2rxssstate(sd);
> > +	struct v4l2_mbus_framefmt *format;
> > +	unsigned int i;
> > +
> > +	mutex_lock(&xcsi2rxss->lock);
> > +	for (i = 0; i < XCSI_MEDIA_PADS; i++) {
> > +		format = v4l2_subdev_get_try_format(sd, cfg, i);
> > +		*format = xcsi2rxss->default_format;
> > +	}
> > +	mutex_unlock(&xcsi2rxss->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * xcsi2rxss_get_format - Get the pad format
> > + * @sd: Pointer to V4L2 Sub device structure
> > + * @cfg: Pointer to sub device pad information structure
> > + * @fmt: Pointer to pad level media bus format
> > + *
> > + * This function is used to get the pad format information.
> > + *
> > + * Return: 0 on success
> > + */
> > +static int xcsi2rxss_get_format(struct v4l2_subdev *sd,
> > +				struct v4l2_subdev_pad_config *cfg,
> > +				struct v4l2_subdev_format *fmt)
> > +{
> > +	struct xcsi2rxss_state *xcsi2rxss = to_xcsi2rxssstate(sd);
> > +
> > +	mutex_lock(&xcsi2rxss->lock);
> > +	fmt->format = *__xcsi2rxss_get_pad_format(xcsi2rxss, cfg, fmt->pad,
> > +						  fmt->which);
> > +	mutex_unlock(&xcsi2rxss->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * xcsi2rxss_set_format - This is used to set the pad format
> > + * @sd: Pointer to V4L2 Sub device structure
> > + * @cfg: Pointer to sub device pad information structure
> > + * @fmt: Pointer to pad level media bus format
> > + *
> > + * This function is used to set the pad format. Since the pad format
> > +is fixed
> > + * in hardware, it can't be modified on run time. So when a format
> > +set is
> > + * requested by application, all parameters except the format type is
> > +saved
> > + * for the pad and the original pad format is sent back to the application.
> > + *
> > + * Return: 0 on success
> > + */
> > +static int xcsi2rxss_set_format(struct v4l2_subdev *sd,
> > +				struct v4l2_subdev_pad_config *cfg,
> > +				struct v4l2_subdev_format *fmt)
> > +{
> > +	struct xcsi2rxss_state *xcsi2rxss = to_xcsi2rxssstate(sd);
> > +	struct v4l2_mbus_framefmt *__format;
> > +	u32 dt;
> > +
> > +	/* only sink pad format can be updated */
> > +	mutex_lock(&xcsi2rxss->lock);
> > +
> > +	/*
> > +	 * Only the format->code parameter matters for CSI as the
> > +	 * CSI format cannot be changed at runtime.
> > +	 * Ensure that format to set is copied to over to CSI pad format
> > +	 */
> > +	__format = __xcsi2rxss_get_pad_format(xcsi2rxss, cfg,
> > +					      fmt->pad, fmt->which);
> > +
> > +	if (fmt->pad == XVIP_PAD_SOURCE) {
> > +		fmt->format = *__format;
> > +		mutex_unlock(&xcsi2rxss->lock);
> > +		return 0;
> > +	}
> > +
> > +	/*
> > +	 * RAW8 is supported in all datatypes. So if requested media bus
> format
> > +	 * is of RAW8 type, then allow to be set. In case core is configured to
> > +	 * other RAW, YUV422 8/10 or RGB888, set appropriate media bus
> format.
> > +	 */
> > +	dt = xcsi2rxss_get_dt(fmt->format.code);
> > +	if (dt != xcsi2rxss->datatype && dt != XCSI_DT_RAW8) {
> > +		dev_dbg(xcsi2rxss->dev, "Unsupported media bus format");
> > +		/* set the default format for the data type */
> > +		fmt->format.code = xcsi2rxss_get_nth_mbus(xcsi2rxss-
> >datatype,
> > +							  0);
> > +	}
> > +
> > +	*__format = fmt->format;
> > +	mutex_unlock(&xcsi2rxss->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * xcsi2rxss_enum_mbus_code - Handle pixel format enumeration
> > + * @sd : pointer to v4l2 subdev structure
> > + * @cfg: V4L2 subdev pad configuration
> > + * @code : pointer to v4l2_subdev_mbus_code_enum structure
> > + *
> > + * Return: -EINVAL or zero on success  */ int
> > +xcsi2rxss_enum_mbus_code(struct v4l2_subdev *sd,
> > +			     struct v4l2_subdev_pad_config *cfg,
> > +			     struct v4l2_subdev_mbus_code_enum *code)
> 
> As commented by the kbuild bot, this function should be static.

Yes I will update this in next version.

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Good to go :-)
> 

Great! 😊 

> > +{
> > +	struct xcsi2rxss_state *state = to_xcsi2rxssstate(sd);
> > +	u32 dt, n;
> > +	int ret = 0;
> > +
> > +	/* RAW8 dt packets are available in all DT configurations */
> > +	if (code->index < 4) {
> > +		n = code->index;
> > +		dt = XCSI_DT_RAW8;
> > +	} else if (state->datatype != XCSI_DT_RAW8) {
> > +		n = code->index - 4;
> > +		dt = state->datatype;
> > +	} else {
> > +		return -EINVAL;
> > +	}
> > +
> > +	code->code = xcsi2rxss_get_nth_mbus(dt, n);
> > +	if (!code->code)
> > +		ret = -EINVAL;
> > +
> > +	return ret;
> > +}
> > +
> > +/*
> > +---------------------------------------------------------------------
> > +--------
> > + * Media Operations
> > + */
> > +
> > +static const struct media_entity_operations xcsi2rxss_media_ops = {
> > +	.link_validate = v4l2_subdev_link_validate };
> > +
> > +static const struct v4l2_subdev_core_ops xcsi2rxss_core_ops = {
> > +	.log_status = xcsi2rxss_log_status,
> > +};
> > +
> > +static const struct v4l2_subdev_video_ops xcsi2rxss_video_ops = {
> > +	.s_stream = xcsi2rxss_s_stream
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops xcsi2rxss_pad_ops = {
> > +	.init_cfg = xcsi2rxss_init_cfg,
> > +	.get_fmt = xcsi2rxss_get_format,
> > +	.set_fmt = xcsi2rxss_set_format,
> > +	.enum_mbus_code = xcsi2rxss_enum_mbus_code,
> > +	.link_validate = v4l2_subdev_link_validate_default,
> > +};
> > +
> > +static const struct v4l2_subdev_ops xcsi2rxss_ops = {
> > +	.core = &xcsi2rxss_core_ops,
> > +	.video = &xcsi2rxss_video_ops,
> > +	.pad = &xcsi2rxss_pad_ops
> > +};
> > +
> > +static int xcsi2rxss_parse_of(struct xcsi2rxss_state *xcsi2rxss) {
> > +	struct device *dev = xcsi2rxss->dev;
> > +	struct device_node *node = dev->of_node;
> > +
> > +	struct fwnode_handle *ep;
> > +	struct v4l2_fwnode_endpoint vep = {
> > +		.bus_type = V4L2_MBUS_CSI2_DPHY
> > +	};
> > +	bool en_csi_v20, vfb;
> > +	int ret;
> > +
> > +	en_csi_v20 = of_property_read_bool(node, "xlnx,en-csi-v2-0");
> > +	if (en_csi_v20)
> > +		xcsi2rxss->en_vcx = of_property_read_bool(node, "xlnx,en-
> vcx");
> > +
> > +	xcsi2rxss->enable_active_lanes =
> > +		of_property_read_bool(node, "xlnx,en-active-lanes");
> > +
> > +	ret = of_property_read_u32(node, "xlnx,csi-pxl-format",
> > +				   &xcsi2rxss->datatype);
> > +	if (ret < 0) {
> > +		dev_err(dev, "missing xlnx,csi-pxl-format property\n");
> > +		return ret;
> > +	}
> > +
> > +	switch (xcsi2rxss->datatype) {
> > +	case XCSI_DT_YUV4228B:
> > +	case XCSI_DT_RGB444:
> > +	case XCSI_DT_RGB555:
> > +	case XCSI_DT_RGB565:
> > +	case XCSI_DT_RGB666:
> > +	case XCSI_DT_RGB888:
> > +	case XCSI_DT_RAW6:
> > +	case XCSI_DT_RAW7:
> > +	case XCSI_DT_RAW8:
> > +	case XCSI_DT_RAW10:
> > +	case XCSI_DT_RAW12:
> > +	case XCSI_DT_RAW14:
> > +		break;
> > +	case XCSI_DT_YUV42210B:
> > +	case XCSI_DT_RAW16:
> > +	case XCSI_DT_RAW20:
> > +		if (!en_csi_v20) {
> > +			ret = -EINVAL;
> > +			dev_dbg(dev, "enable csi v2 for this pixel format");
> > +		}
> > +		break;
> > +	default:
> > +		ret = -EINVAL;
> > +	}
> > +	if (ret < 0) {
> > +		dev_err(dev, "invalid csi-pxl-format property!\n");
> > +		return ret;
> > +	}
> > +
> > +	vfb = of_property_read_bool(node, "xlnx,vfb");
> > +	if (!vfb) {
> > +		dev_err(dev, "operation without VFB is not supported\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
> > +					     XVIP_PAD_SINK, 0,
> > +
> FWNODE_GRAPH_ENDPOINT_NEXT);
> > +	if (!ep) {
> > +		dev_err(dev, "no sink port found");
> > +		return -EINVAL;
> > +	}
> > +
> > +	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
> > +	fwnode_handle_put(ep);
> > +	if (ret) {
> > +		dev_err(dev, "error parsing sink port");
> > +		return ret;
> > +	}
> > +
> > +	dev_dbg(dev, "mipi number lanes = %d\n",
> > +		vep.bus.mipi_csi2.num_data_lanes);
> > +
> > +	xcsi2rxss->max_num_lanes = vep.bus.mipi_csi2.num_data_lanes;
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
> > +					     XVIP_PAD_SOURCE, 0,
> > +
> FWNODE_GRAPH_ENDPOINT_NEXT);
> > +	if (!ep) {
> > +		dev_err(dev, "no source port found");
> > +		return -EINVAL;
> > +	}
> > +
> > +	fwnode_handle_put(ep);
> > +
> > +	dev_dbg(dev, "vcx %s, %u data lanes (%s), data type 0x%02x\n",
> > +		xcsi2rxss->en_vcx ? "enabled" : "disabled",
> > +		xcsi2rxss->max_num_lanes,
> > +		xcsi2rxss->enable_active_lanes ? "dynamic" : "static",
> > +		xcsi2rxss->datatype);
> > +
> > +	return 0;
> > +}
> > +
> > +static int xcsi2rxss_probe(struct platform_device *pdev) {
> > +	struct v4l2_subdev *subdev;
> > +	struct xcsi2rxss_state *xcsi2rxss;
> > +	int num_clks = ARRAY_SIZE(xcsi2rxss_clks);
> > +	struct device *dev = &pdev->dev;
> > +	int irq, ret;
> > +
> > +	xcsi2rxss = devm_kzalloc(dev, sizeof(*xcsi2rxss), GFP_KERNEL);
> > +	if (!xcsi2rxss)
> > +		return -ENOMEM;
> > +
> > +	xcsi2rxss->dev = dev;
> > +
> > +	xcsi2rxss->clks = devm_kmemdup(dev, xcsi2rxss_clks,
> > +				       sizeof(xcsi2rxss_clks), GFP_KERNEL);
> > +	if (!xcsi2rxss->clks)
> > +		return -ENOMEM;
> > +
> > +	/* Reset GPIO */
> > +	xcsi2rxss->rst_gpio = devm_gpiod_get_optional(dev, "video-reset",
> > +						      GPIOD_OUT_HIGH);
> > +	if (IS_ERR(xcsi2rxss->rst_gpio)) {
> > +		if (PTR_ERR(xcsi2rxss->rst_gpio) != -EPROBE_DEFER)
> > +			dev_err(dev, "Video Reset GPIO not setup in DT");
> > +		return PTR_ERR(xcsi2rxss->rst_gpio);
> > +	}
> > +
> > +	ret = xcsi2rxss_parse_of(xcsi2rxss);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	xcsi2rxss->iomem = devm_platform_ioremap_resource(pdev, 0);
> > +	if (IS_ERR(xcsi2rxss->iomem))
> > +		return PTR_ERR(xcsi2rxss->iomem);
> > +
> > +	irq = platform_get_irq(pdev, 0);
> > +	if (irq < 0)
> > +		return irq;
> > +
> > +	ret = devm_request_threaded_irq(dev, irq, NULL,
> > +					xcsi2rxss_irq_handler,
> IRQF_ONESHOT,
> > +					dev_name(dev), xcsi2rxss);
> > +	if (ret) {
> > +		dev_err(dev, "Err = %d Interrupt handler reg failed!\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = clk_bulk_get(dev, num_clks, xcsi2rxss->clks);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* TODO: Enable/disable clocks at stream on/off time. */
> > +	ret = clk_bulk_prepare_enable(num_clks, xcsi2rxss->clks);
> > +	if (ret)
> > +		goto err_clk_put;
> > +
> > +	mutex_init(&xcsi2rxss->lock);
> > +
> > +	xcsi2rxss_hard_reset(xcsi2rxss);
> > +	xcsi2rxss_soft_reset(xcsi2rxss);
> > +
> > +	/* Initialize V4L2 subdevice and media entity */
> > +	xcsi2rxss->pads[XVIP_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> > +	xcsi2rxss->pads[XVIP_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > +
> > +	/* Initialize the default format */
> > +	xcsi2rxss->default_format.code =
> > +		xcsi2rxss_get_nth_mbus(xcsi2rxss->datatype, 0);
> > +	xcsi2rxss->default_format.field = V4L2_FIELD_NONE;
> > +	xcsi2rxss->default_format.colorspace = V4L2_COLORSPACE_SRGB;
> > +	xcsi2rxss->default_format.width = XCSI_DEFAULT_WIDTH;
> > +	xcsi2rxss->default_format.height = XCSI_DEFAULT_HEIGHT;
> > +	xcsi2rxss->format = xcsi2rxss->default_format;
> > +
> > +	/* Initialize V4L2 subdevice and media entity */
> > +	subdev = &xcsi2rxss->subdev;
> > +	v4l2_subdev_init(subdev, &xcsi2rxss_ops);
> > +	subdev->dev = dev;
> > +	strscpy(subdev->name, dev_name(dev), sizeof(subdev->name));
> > +	subdev->flags |= V4L2_SUBDEV_FL_HAS_EVENTS |
> V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	subdev->entity.ops = &xcsi2rxss_media_ops;
> > +	v4l2_set_subdevdata(subdev, xcsi2rxss);
> > +
> > +	ret = media_entity_pads_init(&subdev->entity, XCSI_MEDIA_PADS,
> > +				     xcsi2rxss->pads);
> > +	if (ret < 0)
> > +		goto error;
> > +
> > +	platform_set_drvdata(pdev, xcsi2rxss);
> > +
> > +	ret = v4l2_async_register_subdev(subdev);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to register subdev\n");
> > +		goto error;
> > +	}
> > +
> > +	return 0;
> > +error:
> > +	media_entity_cleanup(&subdev->entity);
> > +	mutex_destroy(&xcsi2rxss->lock);
> > +	clk_bulk_disable_unprepare(num_clks, xcsi2rxss->clks);
> > +err_clk_put:
> > +	clk_bulk_put(num_clks, xcsi2rxss->clks);
> > +	return ret;
> > +}
> > +
> > +static int xcsi2rxss_remove(struct platform_device *pdev) {
> > +	struct xcsi2rxss_state *xcsi2rxss = platform_get_drvdata(pdev);
> > +	struct v4l2_subdev *subdev = &xcsi2rxss->subdev;
> > +	int num_clks = ARRAY_SIZE(xcsi2rxss_clks);
> > +
> > +	v4l2_async_unregister_subdev(subdev);
> > +	media_entity_cleanup(&subdev->entity);
> > +	mutex_destroy(&xcsi2rxss->lock);
> > +	clk_bulk_disable_unprepare(num_clks, xcsi2rxss->clks);
> > +	clk_bulk_put(num_clks, xcsi2rxss->clks);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id xcsi2rxss_of_id_table[] = {
> > +	{ .compatible = "xlnx,mipi-csi2-rx-subsystem-5.0", },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, xcsi2rxss_of_id_table);
> > +
> > +static struct platform_driver xcsi2rxss_driver = {
> > +	.driver = {
> > +		.name		= "xilinx-csi2rxss",
> > +		.of_match_table	= xcsi2rxss_of_id_table,
> > +	},
> > +	.probe			= xcsi2rxss_probe,
> > +	.remove			= xcsi2rxss_remove,
> > +};
> > +
> > +module_platform_driver(xcsi2rxss_driver);
> > +
> > +MODULE_AUTHOR("Vishal Sagar <vsagar@xilinx.com>");
> > +MODULE_DESCRIPTION("Xilinx MIPI CSI-2 Rx Subsystem Driver");
> > +MODULE_LICENSE("GPL v2");
> 
> --
> Regards,
> 
> Laurent Pinchart

Regards
Vishal Sagar