[PATCH v12 04/15] media: uapi: Add controls for Mali-C55 ISP

Jacopo Mondi jacopo.mondi at ideasonboard.com
Thu Oct 2 03:51:46 PDT 2025


Hi Dan

On Thu, Oct 02, 2025 at 11:18:23AM +0100, Daniel Scally wrote:
> Add definitions and documentation for the custom control that will
> be needed by the Mali-C55 ISP driver. This will be a read only
> bitmask of the driver's capabilities, informing userspace of which
> blocks are fitted and which are absent.
>
> Signed-off-by: Daniel Scally <dan.scally at ideasonboard.com>
> ---
> Changes in v12:
>
> 	- Removed _FITTED suffix from control value names
> 	- Specified bitmask for control name
> 	- Used (1 << n) instead of BIT(n) in uapi header
> 	- Updated comment to reserve 16 controls for driver
>
> Changes in v11:
>
> 	- None
> Changes in v10:
>
> 	- None
>
> Changes in v9:
>
> 	- New patch
> ---
>  .../userspace-api/media/drivers/index.rst          |  1 +
>  .../userspace-api/media/drivers/mali-c55.rst       | 55 ++++++++++++++++++++++
>  include/uapi/linux/media/arm/mali-c55-config.h     | 26 ++++++++++
>  include/uapi/linux/v4l2-controls.h                 |  6 +++
>  4 files changed, 88 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst
> index d706cb47b1122b6e145a02ab826eb3ecc7997c2b..02967c9b18d6e90f414ccc1329c09bffee895e68 100644
> --- a/Documentation/userspace-api/media/drivers/index.rst
> +++ b/Documentation/userspace-api/media/drivers/index.rst
> @@ -32,6 +32,7 @@ For more details see the file COPYING in the source distribution of Linux.
>  	cx2341x-uapi
>  	dw100
>  	imx-uapi
> +	mali-c55
>  	max2175
>  	npcm-video
>  	omap3isp-uapi
> diff --git a/Documentation/userspace-api/media/drivers/mali-c55.rst b/Documentation/userspace-api/media/drivers/mali-c55.rst
> new file mode 100644
> index 0000000000000000000000000000000000000000..74f2cdb717e0dddeb11fb1eaba69eeebb2534f95
> --- /dev/null
> +++ b/Documentation/userspace-api/media/drivers/mali-c55.rst
> @@ -0,0 +1,55 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +Arm Mali-C55 ISP driver
> +=======================
> +
> +The Arm Mali-C55 ISP driver implements a single driver-specific control:
> +
> +``V4L2_CID_MALI_C55_CAPABILITIES (bitmask)``
> +    Detail the capabilities of the ISP by giving detail about the fitted blocks.
> +
> +    .. flat-table:: Bitmask meaning definitions
> +	:header-rows: 1
> +	:widths: 2 4 8
> +
> +	* - Bit

I see the other (bitmask) controls not specifying the bit but only the
macro. To me, this is fine as it is, but I'm just pointing it out.


> +	  - Macro
> +	  - Meaning
> +        * - 0
> +          - MALI_C55_GPS_PONG

GPS is the register name, not sure it has value here.

With maybe "GPS" rmeove, if you agree
Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

Thanks
  j


> +          - Pong configuration space is fitted in the ISP
> +        * - 1
> +          - MALI_C55_GPS_WDR
> +          - WDR Framestitch, offset and gain is fitted in the ISP
> +        * - 2
> +          - MALI_C55_GPS_COMPRESSION
> +          - Temper compression is fitted in the ISP
> +        * - 3
> +          - MALI_C55_GPS_TEMPER
> +          - Temper is fitted in the ISP
> +        * - 4
> +          - MALI_C55_GPS_SINTER_LITE
> +          - Sinter Lite is fitted in the ISP instead of the full Sinter version
> +        * - 5
> +          - MALI_C55_GPS_SINTER
> +          - Sinter is fitted in the ISP
> +        * - 6
> +          - MALI_C55_GPS_IRIDIX_LTM
> +          - Iridix local tone mappine is fitted in the ISP
> +        * - 7
> +          - MALI_C55_GPS_IRIDIX_GTM
> +          - Iridix global tone mapping is fitted in the ISP
> +        * - 8
> +          - MALI_C55_GPS_CNR
> +          - Colour noise reduction is fitted in the ISP
> +        * - 9
> +          - MALI_C55_GPS_FRSCALER
> +          - The full resolution pipe scaler is fitted in the ISP
> +        * - 10
> +          - MALI_C55_GPS_DS_PIPE
> +          - The downscale pipe is fitted in the ISP
> +
> +    The Mali-C55 ISP can be configured in a number of ways to include or exclude
> +    blocks which may not be necessary. This control provides a way for the
> +    driver to communicate to userspace which of the blocks are fitted in the
> +    design.
> \ No newline at end of file
> diff --git a/include/uapi/linux/media/arm/mali-c55-config.h b/include/uapi/linux/media/arm/mali-c55-config.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..7fddece54ada9dadc3c76372d496d9395237a41c
> --- /dev/null
> +++ b/include/uapi/linux/media/arm/mali-c55-config.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * ARM Mali-C55 ISP Driver - Userspace API
> + *
> + * Copyright (C) 2023 Ideas on Board Oy
> + */
> +
> +#ifndef __UAPI_MALI_C55_CONFIG_H
> +#define __UAPI_MALI_C55_CONFIG_H
> +
> +#include <linux/v4l2-controls.h>
> +
> +#define V4L2_CID_MALI_C55_CAPABILITIES	(V4L2_CID_USER_MALI_C55_BASE + 0x0)
> +#define MALI_C55_GPS_PONG		(1U << 0)
> +#define MALI_C55_GPS_WDR		(1U << 1)
> +#define MALI_C55_GPS_COMPRESSION	(1U << 2)
> +#define MALI_C55_GPS_TEMPER		(1U << 3)
> +#define MALI_C55_GPS_SINTER_LITE	(1U << 4)
> +#define MALI_C55_GPS_SINTER		(1U << 5)
> +#define MALI_C55_GPS_IRIDIX_LTM		(1U << 6)
> +#define MALI_C55_GPS_IRIDIX_GTM		(1U << 7)
> +#define MALI_C55_GPS_CNR		(1U << 8)
> +#define MALI_C55_GPS_FRSCALER		(1U << 9)
> +#define MALI_C55_GPS_DS_PIPE		(1U << 10)
> +
> +#endif /* __UAPI_MALI_C55_CONFIG_H */
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 2d30107e047ee3cf6b149e5b075cc9d4137b7d3f..f84ed133a6c9b2ddc1aedbd582ddf78cb71f34e5 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -228,6 +228,12 @@ enum v4l2_colorfx {
>   */
>  #define V4L2_CID_USER_RKISP1_BASE		(V4L2_CID_USER_BASE + 0x1220)
>
> +/*
> + * The base for the Arm Mali-C55 ISP driver controls.
> + * We reserve 16 controls for this driver
> + */
> +#define V4L2_CID_USER_MALI_C55_BASE		(V4L2_CID_USER_BASE + 0x1230)
> +
>  /* MPEG-class control IDs */
>  /* The MPEG controls are applicable to all codec controls
>   * and the 'MPEG' part of the define is historical */
>
> --
> 2.43.0
>



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