RE: [PATCH v9 00/21] media: i2c: add Maxim GMSL2/3 serializer and deserializer drivers

[Dayananda, Vivekananda]

[AMD Official Use Only - AMD Internal Distribution Only]

Hi Dumitru, Sakari,

Thank you for the latest patch series. We have been validating this
on the following test infrastructure:

- IMX219 image sensor
- MAX96724 deserializer
- MAX96717 serializer

With this setup the v9 drivers operate as expected and we are able to
exercise streaming end-to-end.

One item worth noting: our deserializer sits on a custom daughter card
where the I2C bus is routed through port 1. The current MAX96724 driver
only supports I2C on port 0. It would be valuable to extend the driver
to support additional I2C port configurations so that setups like ours
can be accommodated.

Vivek

> -----Original Message-----
> From: Dumitru Ceclan via B4 Relay
> <devnull+dumitru.ceclan.analog.com@xxxxxxxxxx>
> Sent: Wednesday, March 11, 2026 12:17 AM
> To: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>; Mauro
> Carvalho Chehab <mchehab@xxxxxxxxxx>; Sakari Ailus
> <sakari.ailus@xxxxxxxxxxxxxxx>; Laurent Pinchart
> <laurent.pinchart@xxxxxxxxxxxxxxxx>; Julien Massot
> <julien.massot@xxxxxxxxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; Niklas
> Söderlund <niklas.soderlund@xxxxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
> Cc: mitrutzceclan@xxxxxxxxx; linux-media@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> staging@xxxxxxxxxxxxxxx; linux-gpio@xxxxxxxxxxxxxxx; Niklas Söderlund
> <niklas.soderlund+renesas@xxxxxxxxxxxx>; Martin Hecht
> <Martin.Hecht@xxxxxxxx>; Tomi Valkeinen
> <tomi.valkeinen@xxxxxxxxxxxxxxxx>; Cosmin Tanislav
> <demonsingur@xxxxxxxxx>; Cory Keitz <ckeitz@xxxxxxxxxx>
> Subject: [PATCH v9 00/21] media: i2c: add Maxim GMSL2/3 serializer and
> deserializer drivers
>
> This series adds new drivers for multiple Maxim GMSL2 and GMSL3 devices,
> replacing the few GMSL2 drivers already in upstream, and introducing a common
> framework that can be used to implement such GMSL chips, which avoids code
> duplication while also adding support for previously unsupported features.
>
> While the normally acceptable and polite way would be to extend the current
> mainline drivers, the choice was made here to add a totally new set of drivers.
> The current drivers support only a small subset of the possible features, and only
> a few devices, so the end result after extending them would in any case be
> essentially fully rewritten, new drivers.
>
> This series depends on support for internal pads, for which a patch has been
> added.
>
> The previous version is at:
> https://lore.kernel.org/all/20250718152500.2656391-1-
> demonsingur@xxxxxxxxx/
>
> Since the previous series, Cosmin has left Analog Devices.
> Because included changes from previous version are trivial, his sign-off and tags
> were retained.
>
> The following deserializers are supported:
> * MAX96712 (already exists in staging)
> * MAX96714 (already exists)
> * MAX96714F (already exists)
> * MAX96714R (GMSL2)
> * MAX96716 (GMSL2)
> * MAX96724 (already exists as part of existing MAX96712 driver)
> * MAX96724F (GMSL2)
> * MAX96724R (GMSL2)
> * MAX9296A (GMSL2)
> * MAX96792A (GMSL3)
>
> The following serializers are supported:
> * MAX96717 (already exists)
> * MAX9295A (GMSL2)
> * MAX96793 (GMSL3)
>
> The following list enumerates new features that are supported by the common
> framework and their respective chip-specific drivers:
> * Full Streams API support. Most deserializers have support for more than one
> link, and more than one PHY. Streams support allows configuration of routing
> between these links and PHYs.
>
> * .get_frame_desc() support. Both the serializers and deserializers implement this
> to query and provide frame descriptor data. This is used in features explained in-
> depth below.
>
> * .get_mbus_config() support. The deserializers implement this to allow upstream
> devices to query the link frequency of its pads.
>
> * Address translation with I2C ATR for the serializers.
>
> * I2C ATR translation - some deserializers cannot do muxing since I2C
> communication channel masking is not available per-link, and the only other way
> to select links is to turn them off, causing link resets.
> For such cases, I2C ATR is used to change the address of the serializers at probe
> time.
>
> * Automatic GMSL link version negotiation between GMSL3, GMSL2 6Gbps,
> GMSL2 3Gbps.
>
> * Automatic stream id selection for deserializers which need serializers to stream
> on unique stream ids.
>
> * Automatic VC remapping on the deserializers. VCs are picked so that if they
> were unique on the sink pad, they will end up as unique on the source pad they
> are routed to too, prioritizing using the same VC ID as the sink pad, to facilitate
> the possibility of using tunnel mode.
>
> * Automatic pixel mode / tunnel mode selection. Tunnel mode is used when VC
> IDs do not need to be changed and all hardware supports tunnel mode,
> otherwise, pixel mode is used. The serializers are automatically switched
> between the two by using a private API.
>
> * Automatic double mode selection. In pixel mode, double mode can be used to
> pack two pixels into a single data unit, optimizing bandwidth usage. The
> serializers are automatically set up to support the double modes determined by
> the deserializers using a private API.
>
> * Automatic data padding. In pixel mode, if the data being transferred uses two
> different BPPs, data needs to be padded. The serializers automatically set this up
> depending on the configured double mode settings and incoming data types.
>
> * Logging. Both the deserializers and serializers implement the V4L2
> .log_status() ops to allow debugging of the internal state and important chip
> status registers.
>
> * PHY modes. Deserializer chips commonly have more than a single PHY.
> The firmware ports are parsed to determine the modes in which to configure the
> PHYs (2x4, 4x2, 1x4+2x2, 2x2+1x4, and variations using fewer lanes).
>
> * Serializer pinctrl. Serializers implement pinctrl to allow setting configs which
> would otherwise be inaccessible through GPIO: TX/RX via GMSL link, pull-up &
> pull-down (with strength), open-drain & push-pull, slew rate, RCLK pin selection.
>
> * TPG with selectable formats, resolutions and framerates for both serializers and
> deserializers.
>
> The drivers have been tested on the following hardware combinations, but further
> testing is welcome to ensure no / minimal breakage:
> * Raspberry Pi 5 + MAX9296A + 2xMAX96717 + 2xIMX219
> * Raspberry Pi 5 + MAX96714 + 1xMAX96717 + 1xIMX219
> * Raspberry Pi 5 + MAX96716A + 2xMAX96717 + 2xIMX219
> * Raspberry Pi 5 + MAX96712 + 4xMAX96717 + 4xIMX219
> * Raspberry Pi 5 + MAX96724 + 4xMAX96717 + 4xIMX219
> * Raspberry Pi 5 + MAX96792A + 1xMAX96793 + 1xMAX96717 + 2xIMX219
> * Raspberry Pi 5 + MAX96792A + 2xMAX96717 + 2xIMX219
> * Renesas V4H + MAX96712 + 2xMAX96717 + 2xIMX219
>
> Analog Devices is taking responsibility for the maintenance of these drivers and
> common framework, and plans to add support for new broad-market chips on top
> of them.
>
> Special thanks go to Tomi Valkeinen <
> tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> for testing the drivers, helping debug and coming up with ideas / implementations
> for various features.
>
> The following v4l2-compliance test still fails:
>                 fail: v4l2-test-subdevs.cpp(371): fmt.code == 0 || fmt.code == ~0U
>                 fail: v4l2-test-subdevs.cpp(418): checkMBusFrameFmt(node, fmt.format)
>         test Active VIDIOC_SUBDEV_G/S_FMT: FAIL
>
> As the serializers and deserializers are format agnostic and the values set are not
> used to configure anything in the chips, this test does not make much sense in this
> context. If needed, a check for the specific ~0U value can be added.
>
> V9:
> * split max_des_ops into *_info and *_ops
> * use read_poll_timeout macro in *_wait_for_device()
> * return read_poll_timeout error -ETIMEDOUT in *_wait_for_device()
> * remove use_atr duplicate from max9296a_chip_info, present in max_des_info
> * fix max9296a DPLL register offset
> * fix C-PHY DPLL frequency in max9296a and max96724
>     reported by: Cory Keitz <ckeitz@xxxxxxxxxx>
> * use MAX9296A_COMMON_INFO and MAX9296A_COMMON_OPS to simplify
>   probe ops init
> * fix borked patches in previous version, actually remove MAX96717 and
>   MAX96714 drivers
>
> V8:
> * max96717: use the renamed PIN_CONFIG_OUTPUT to _LEVEL
> * max96717: use the renamed set_rv ops from struct gpio_chip
> * dt-bindings: set minItems lane-polarities to 2
> * dt-bindings: "add myself as maintainer" commits were removed
> * max_des & max_ser: use a default format for set_routing
> * max_des & max_ser: return ENNOTTY in *_frame_interval for non-TPG pads
>
> V7:
> * dt-bindings: max9296a: use full max96717 compatible
> * max9296a: make max96714_rlms_reg_sequence static
> * explicitly include linux/bitfield.h
> * explicitly depend on I2C and PINCTRL
> * sort media_entity_operations
> * add has_pad_interdep to media_entity_operations
>
> V6:
> * max9296a: put rlms sequence in max9296a_chip_info
> * max_des: reflow stream id a comment
> * max_ser: remove exported symbols not used in other modules
> * max_ser: init mode to a supported value
> * add default routing
> * MAX_SERDES_GMSL_3 -> MAX_SERDES_GMSL_3_12GBPS
> * guard reg_read/write with CONFIG_VIDEO_ADV_DEBUG
> * put exported symbols in MAXIM_SERDES namespace
>
> V5:
> * dt-bindings: max96717: restrict RCLKOUT to pins 2 & 4
> * dt-bindings: max96717: remove confusing rclksel pinconf property
> * dt-bindings: max96717: remove maxim,gmsl-tx/rx pinconf property
> * dt-bindings: max96717: remove gmsl prefix from maxim,gmsl-tx-id/rx-id
> * dt-bindings: max96717: remove minimum: 0
> * dt-bindings: max96717: better document slew-rate
> * dt-bindings: max96717: better document maxim,jitter-compensation
> * dt-bindings: max96717: better document maxim,tx-id/rx-id
>
> * max_serdes: add default TPG values
> * max_serdes: remove MAX_MIPI_FMT macro
> * max_serdes: EXPORT_SYMBOL -> EXPORT_SYMBOL_GPL
> * max_serdes: remove EXPORT_SYMBOL_GPL from symbols not used in other
> modules
> * max_serdes: rename symbols/macros/types to have max_serdes prefix
> * max_serdes: slim down TPG functions
>
> * max_des: fix may be used uninitialized errors
> * max_des: fix misplaced TPG validation
> * max_des: fix setting pipe PHY in tunnel mode for chips that support both
> set_pipe_phy() and set_pipe_tunnel_phy()
> * max_des: move doubled_bpp/sink_bpps variables to usage place
> * max_des: do not dynamically control PHY enable, letting lanes be in
> LP-11 when not streaming
> * max_des: refactor get/set_pipe_stream_id() logic
> * max_des: remove explicit ret = 0
>
> * max_ser: make VC remaps not pipe-specific, allocate dynamically
>
> * max9296a: add missing 1080p30 TPG entry
> * max9296a: move BIT() left shift into macro
> * max9296a: move BIT() ternary into macro
> * max9296a: reuse max_des_ops for chip-specific ops\
> * max9296a: document and compress RLMS register writes
>
> * max96717: restrict RCLKOUT to pins 2 & 4 because of hardware capabilities
> * max96717: add support for XTAL/1, XTAL/2, XTAL/4 clocks
> * max96717: set RX_EN/TX_EN automatically
> * max96717: reorder custom pinconf flags
> * max96717: drop OF dependency
>
> * drop of_match_ptr
> * re-do some indentation
> * implement TPG pattern control
> * remove pr_info() usage
> * inline lane polarity val = 0
> * inline returns
> * rewrite some Kconfig docs
> * split up patches for easier review
>
> V4:
> * max_des: fix infinite version loop
> * max_des: fix pipe link id when there are more pipes than links
> * max_des: implement setting pipe link
> * max_des: do not pass routing to phy update
> * max_des: move GMSL version strings to max_serdes
> * max_des: split finding existing VC remap from adding a new one
> * max_des: add tracking for in-use pipes
> * max_des: skip unused pipes when finding / setting pixel/tunnel mode
> * max_des: simplify remap code
> * max_des: split set_pipe_phy() into set_pipe_tunnel_phy()
>
> * max_ser: clean up i2c_xlates printing
> * max_ser: fix changing serializer address
> * max_ser: move non-continuous mode check into max96717 driver
>
> * max96724: use regmap_set_bits for STREAM_SEL_ALL
> * max96724: match surrounding indent for MAX96724_PHY1_ALT_CLOCK
> * max96724: fix setting invalid PHY to 1 when PHY 0 is in 4-lane mode
> * max96724: remove support for setting pipe phy from max96712
> * max96724: fix setting double mode on pipes 4-7
> * max96724: drop powerdown gpios
>
> * max96717: use gpio_chip's set_rv
>
> * max9296a: switch versions to unsigned int
> * max9296a: remove parantheses from MAX9296A_MIPI_PHY18/20
> * max9296a: fix printing of PHY packet counts
> * max9296a: fix phy_hw_ids size
>
> * remove usage of cammel case in defines
> * move field_get/prep to max_serdes.h
> * rework stream id setup
> * rework tunnel/pixel mode finding
> * rework bpps retrieval
> * pass whole subdev state around
> * add helper for retrieving a route's hw components / frame desc
> * update pipe enable based on active routes
> * add support for tunnel-only chips and VC remaps in tunnel mode
> * simplify max_get_streams_masks()
> * add support for TPG
>
> V3:
> * dt-bindings: drop reflow text patches
>
> * dt-bindings: max96717: move pinctrl configuration into main file
> * dt-bindings: max96717: allow a single level of pins configuration
> * dt-bindings: max96717: use regex for matching pins nodes
> * dt-bindings: max96717: drop extra allOf in pinctrl configuration
> * dt-bindings: max96717: fix i2c-atr channel name regex
> * dt-bindings: max96717: limit pinctrl functions to gpio / rclkout
> * dt-bindings: max96717: limit pins for gpio / rclkout
> * dt-bindings: max96717: add description for bias-pull-up/down
> * dt-bindings: max96717: require pins and function properties
> * dt-bindings: max96717: turn single compatible strings into an enum
>
> * dt-bindings: max9296a: include indices in port descriptions
> * dt-bindings: max9296a: remove property-less schema from input ports
> * dt-bindings: max9296a: use ATR for MAX96716A too, removing MUX entirely
>
> * dt-bindings: max96712: include indices in port descriptions
> * dt-bindings: max96712: deprecate enable-gpios in favor of powerdown-gpios
> * dt-bindings: max96712: switch from MUX to ATR
>
> * dt-bindings: max96714: add support for MAX96714R
>
> * max_des: fix POC NULL check
> * max_des: remove index var in POC enable
> * max_des: fix writing empty remaps
> * max_des: skip mode setting in tunnel mode
> * max_des: remove a duplicate source->sd NULL check
> * max_des: set pipe tunnel mode even for disabled links
>
> * max_ser: apply TX ID changes irrespective of serializer ID
>
> * max9296a: fix typo in BACKTOP22
> * max9296a: make register macros more consistent
> * max9296a: switch MAX96716 from MUX to ATR
> * max9296a: deduplicate max9296a_phy_id() logic
> * max9296a: use proper PHY id in remaps
> * max9296a: fix DPLL reset clear
> * max9296a: limit MAX96714F to GMSL2 3Gbps
> * max9296a: add support for MAX96714R
> * max9296a: do not write GMSL3 link select registers in GMSL2 devices
> * max9296a: use field_prep when setting RX_RATE
> * max9296a: simplify setting SEL_STREAM for MAX96714
> * max9296a: max96716_set_pipe_phy -> max96716a_set_pipe_phy
> * max9296a: fix off-by-one in lane polarity when using
> polarity_on_physical_lanes
>
> * max96724: fix typo in BACKTOP22
> * max96724: switch from MUX to ATR
> * max96724: add support for powerdown GPIO
> * max96724: remove support for tunneling from MAX96712
> * max96724: only set tunnel-related bits when in tunnel mode
> * max96724: add support for MAX96724F/R
> * max96724: oneshot reset links after link selection
>
> * remove GMSL2 version defaults, set all supported versions explicitly
> * reorder GMSL versions to start from 0
> * add support for GMSL2 3Gbps
> * support GMSL version finding for devices using MUX / GATE
> * add support for deserializers which don't have individual control of each link's
> GMSL version
> * add support for deserializers that need unique stream ids across all serializers
> * select_link_version -> set_link_version
> * select_resets_link -> use_atr
>
> V2:
> * add missing compatible for MAX96717F
> * fix embarrassing dt-bindings mistakes
> * move MAX9296A/MAX96716/MAX96792A to a separate file as they have two
> links / PHYs, and adding those conditionally seems impossible
> ---
> Cosmin Tanislav (20):
>       dt-bindings: media: i2c: max96717: add support for I2C ATR
>       dt-bindings: media: i2c: max96717: add support for pinctrl/pinconf
>       dt-bindings: media: i2c: max96717: add support for MAX9295A
>       dt-bindings: media: i2c: max96717: add support for MAX96793
>       dt-bindings: media: i2c: max96712: use pattern properties for ports
>       dt-bindings: media: i2c: max96712: add support for I2C ATR
>       dt-bindings: media: i2c: max96712: add support for POC supplies
>       dt-bindings: media: i2c: max96712: add support for MAX96724F/R
>       dt-bindings: media: i2c: max96714: add support for MAX96714R
>       dt-bindings: media: i2c: add MAX9296A, MAX96716A, MAX96792A
>       media: i2c: add Maxim GMSL2/3 serializer and deserializer framework
>       media: i2c: add Maxim GMSL2/3 serializer framework
>       media: i2c: add Maxim GMSL2/3 deserializer framework
>       media: i2c: maxim-serdes: add MAX96717 driver
>       media: i2c: maxim-serdes: add MAX96724 driver
>       media: i2c: maxim-serdes: add MAX9296A driver
>       arm64: defconfig: disable deprecated MAX96712 driver
>       staging: media: remove MAX96712 driver
>       media: i2c: remove MAX96717 driver
>       media: i2c: remove MAX96714 driver
>
> Sakari Ailus (1):
>       media: mc: Add INTERNAL pad flag
>
>  .../bindings/media/i2c/maxim,max9296a.yaml         |  242 ++
>  .../bindings/media/i2c/maxim,max96712.yaml         |   65 +-
>  .../bindings/media/i2c/maxim,max96714.yaml         |    5 +-
>  .../bindings/media/i2c/maxim,max96717.yaml         |  154 +-
>  .../userspace-api/media/mediactl/media-types.rst   |    9 +
>  MAINTAINERS                                        |   10 +-
>  arch/arm64/configs/defconfig                       |    1 -
>  drivers/media/i2c/Kconfig                          |   34 +-
>  drivers/media/i2c/Makefile                         |    3 +-
>  drivers/media/i2c/max96714.c                       | 1017 -------
>  drivers/media/i2c/max96717.c                       | 1102 -------
>  drivers/media/i2c/maxim-serdes/Kconfig             |   60 +
>  drivers/media/i2c/maxim-serdes/Makefile            |    6 +
>  drivers/media/i2c/maxim-serdes/max9296a.c          | 1358 +++++++++
>  drivers/media/i2c/maxim-serdes/max96717.c          | 1686 +++++++++++
>  drivers/media/i2c/maxim-serdes/max96724.c          | 1193 ++++++++
>  drivers/media/i2c/maxim-serdes/max_des.c           | 3188
> ++++++++++++++++++++
>  drivers/media/i2c/maxim-serdes/max_des.h           |  156 +
>  drivers/media/i2c/maxim-serdes/max_ser.c           | 2138 +++++++++++++
>  drivers/media/i2c/maxim-serdes/max_ser.h           |  147 +
>  drivers/media/i2c/maxim-serdes/max_serdes.c        |  413 +++
>  drivers/media/i2c/maxim-serdes/max_serdes.h        |  183 ++
>  drivers/media/mc/mc-entity.c                       |   15 +-
>  drivers/staging/media/Kconfig                      |    2 -
>  drivers/staging/media/Makefile                     |    1 -
>  drivers/staging/media/max96712/Kconfig             |   14 -
>  drivers/staging/media/max96712/Makefile            |    2 -
>  drivers/staging/media/max96712/max96712.c          |  487 ---
>  include/uapi/linux/media.h                         |    1 +
>  29 files changed, 11006 insertions(+), 2686 deletions(-)
> ---
> base-commit: a15a902a91b78f1544760fb52ef0151f83815f81
> change-id: 20251107-gmsl2-3_serdes-3f2b885209c3
>
> Best regards,