Re: [RFC PATCH 1/3] uapi/linux/media.h: add property support

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

Em Fri,  3 Aug 2018 16:36:24 +0200
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add a new topology struct that includes properties.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  include/uapi/linux/media.h | 62 +++++++++++++++++++++++++++++++++++++-
>  1 file changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
> index 36f76e777ef9..dd8c96a17020 100644
> --- a/include/uapi/linux/media.h
> +++ b/include/uapi/linux/media.h
> @@ -342,6 +342,61 @@ struct media_v2_link {
>  	__u32 reserved[6];
>  } __attribute__ ((packed));
>  
> +#define MEDIA_PROP_TYPE_U64	1
> +#define MEDIA_PROP_TYPE_S64	2
> +#define MEDIA_PROP_TYPE_STRING	3
> +
> +/**
> + * struct media_v2_prop - A media property
> + *
> + * @id:		The unique non-zero ID of this property
> + * @owner_id:	The ID of the object this property belongs to
> + * @type:	Property type
> + * @flags:	Property flags
> + * @payload_size: Property payload size, 0 for U64/S64
> + * @payload_offset: Property payload starts at this offset from &prop.id.
> + *		This is 0 for U64/S64.
> + * @reserved:	Property reserved field, will be zeroed.
> + * @name:	Property name
> + * @uval:	Property value (unsigned)
> + * @sval:	Property value (signed)
> + */
> +struct media_v2_prop {
> +	__u32 id;
> +	__u32 owner_id;
> +	__u32 type;
> +	__u32 flags;
> +	__u32 payload_size;
> +	__u32 payload_offset;
> +	__u32 reserved[18];
> +	char name[32];
> +	union {
> +		__u64 uval;
> +		__s64 sval;
> +	};
> +} __attribute__ ((packed));
> +
> +/* Old version 1 of this struct */
> +struct media_v2_topology_1 {
> +	__u64 topology_version;
> +
> +	__u32 num_entities;
> +	__u32 reserved1;
> +	__u64 ptr_entities;
> +
> +	__u32 num_interfaces;
> +	__u32 reserved2;
> +	__u64 ptr_interfaces;
> +
> +	__u32 num_pads;
> +	__u32 reserved3;
> +	__u64 ptr_pads;
> +
> +	__u32 num_links;
> +	__u32 reserved4;
> +	__u64 ptr_links;
> +} __attribute__ ((packed));
> +

As I said at patch 0/3, no need to keep it at the public header. you'll
need this only at media-device.c, just in order to do:

sizeof(old_struct)

>  struct media_v2_topology {
>  	__u64 topology_version;
>  
> @@ -360,6 +415,10 @@ struct media_v2_topology {
>  	__u32 num_links;
>  	__u32 reserved4;
>  	__u64 ptr_links;
> +
> +	__u32 num_props;
> +	__u32 props_payload_size;
> +	__u64 ptr_props;
>  } __attribute__ ((packed));
>  
>  /* ioctls */
> @@ -368,7 +427,8 @@ struct media_v2_topology {
>  #define MEDIA_IOC_ENUM_ENTITIES	_IOWR('|', 0x01, struct media_entity_desc)
>  #define MEDIA_IOC_ENUM_LINKS	_IOWR('|', 0x02, struct media_links_enum)
>  #define MEDIA_IOC_SETUP_LINK	_IOWR('|', 0x03, struct media_link_desc)
> -#define MEDIA_IOC_G_TOPOLOGY	_IOWR('|', 0x04, struct media_v2_topology)
> +#define MEDIA_IOC_G_TOPOLOGY_1	_IOWR('|', 0x04, struct media_v2_topology_1)
> +#define MEDIA_IOC_G_TOPOLOGY	_IOWR('|', 0x05, struct media_v2_topology)

Why renaming it? No need at all. Just keep the original definition,
and let media-device.c to handle the different ioctl sizes.

Thanks,
Mauro