Re: [PATCH 07/12] video/hdmi: Introduce helpers for the HDMI vendor specific infoframe

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Aug 14, 2013 at 12:17:23AM +0100, Damien Lespiau wrote:
> Provide the programming model than the other infoframe types.
> 
> The generic _pack() function can't handle those yet as we need to move
> the vendor OUI in the generic hdmi_vendor_infoframe structure to know
> which kind of vendor infoframe we are dealing with.
> 
> Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
> ---
>  drivers/video/hdmi.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/hdmi.h | 25 ++++++++++++++++
>  2 files changed, 107 insertions(+)
> 
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index ac84215..2059f7b 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -286,6 +286,88 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>  EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
>  
>  /**
> + * hdmi_hdmi_infoframe_init() - initialize an HDMI vendor infoframe
> + * @frame: HDMI vendor infoframe
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_hdmi_infoframe_init(struct hdmi_hdmi_infoframe *frame)
> +{
> +	memset(frame, 0, sizeof(*frame));
> +
> +	frame->type = HDMI_INFOFRAME_TYPE_VENDOR;
> +	frame->version = 1;
> +	frame->length = 5; /* we can hardcode the size for now as we don't
> +			    support neither 3D_Ext_Data nor 3D_Metadata_* */
> +
> +	/* 0 is a valid value for s3d_struct, so we use a special "not set"
> +	 * value */
> +	frame->s3d_struct = HDMI_3D_STRUCTURE_INVALID;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(hdmi_hdmi_infoframe_init);
> +
> +/**
> + * hdmi_hmdi_infoframe_pack() - write a HDMI vendor infoframe to binary buffer
> + * @frame: HDMI infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Packs the information contained in the @frame structure into a binary
> + * representation that can be written into the corresponding controller
> + * registers. Also computes the checksum as required by section 5.3.5 of
> + * the HDMI 1.4 specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t hdmi_hdmi_infoframe_pack(struct hdmi_hdmi_infoframe *frame,
> +				 void *buffer, size_t size)
> +{
> +	u8 *ptr = buffer;
> +	size_t length;
> +
> +	/* empty info frame */
> +	if (frame->vic == 0 && frame->s3d_struct == HDMI_3D_STRUCTURE_INVALID)
> +		return -EINVAL;
> +
> +	/* only one of those can be supplied */
> +	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
> +		return -EINVAL;
> +
> +	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
> +
> +	if (size < length)
> +		return -ENOSPC;
> +
> +	memset(buffer, 0, size);
> +
> +	ptr[0] = frame->type;
> +	ptr[1] = frame->version;
> +	ptr[2] = frame->length;
> +	ptr[3] = 0; /* checksum */
> +
> +	/* HDMI OUI */
> +	ptr[4] = 0x03;
> +	ptr[5] = 0x0c;
> +	ptr[6] = 0x00;
> +
> +	if (frame->vic) {
> +		ptr[7] = 0x1 << 5;	/* video format */
> +		ptr[8] = frame->vic;
> +	} else {
> +		ptr[7] = 0x2 << 5;	/* video format */
> +		ptr[8] = (frame->s3d_struct & 0xf) << 4;
> +	}
> +
> +	hdmi_infoframe_checksum(buffer, length);
> +
> +	return length;
> +}
> +EXPORT_SYMBOL(hdmi_hdmi_infoframe_pack);
> +
> +/**
>   * hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary
>   *                                buffer
>   * @frame: HDMI vendor infoframe
> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> index b98340b..f5098a8 100644
> --- a/include/linux/hdmi.h
> +++ b/include/linux/hdmi.h
> @@ -234,11 +234,36 @@ struct hdmi_vendor_infoframe {
>  ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
>  				   void *buffer, size_t size);
>  
> +enum hdmi_3d_structure {
> +	HDMI_3D_STRUCTURE_INVALID = -1,
> +	HDMI_3D_STRUCTURE_FRAME_PACKING = 0,
> +	HDMI_3D_STRUCTURE_FIELD_ALTERNATIVE,
> +	HDMI_3D_STRUCTURE_LINE_ALTERNATIVE,
> +	HDMI_3D_STRUCTURE_SIDE_BY_SIDE_FULL,
> +	HDMI_3D_STRUCTURE_L_DEPTH,
> +	HDMI_3D_STRUCTURE_L_DEPTH_GFX_GFX_DEPTH,
> +	HDMI_3D_STRUCTURE_TOP_BOTTOM,

TOP_AND_BOTTOM maybe?

> +	HDMI_3D_STRUCTURE_SIDE_BY_SIDE_HALF,

The value of this should be 8. Also according to the spec
we must send 3d_ext_data when when 3d_structure >= 8, so
either we need a bit more code, or we need to disallow
3d_structure >= 8 for the time being.

> +};
> +
> +struct hdmi_hdmi_infoframe {
> +	enum hdmi_infoframe_type type;
> +	unsigned char version;
> +	unsigned char length;
> +	u8 vic;
> +	enum hdmi_3d_structure s3d_struct;
> +};
> +
> +int hdmi_hdmi_infoframe_init(struct hdmi_hdmi_infoframe *frame);
> +ssize_t hdmi_hdmi_infoframe_pack(struct hdmi_hdmi_infoframe *frame,
> +				 void *buffer, size_t size);
> +
>  union hdmi_infoframe {
>  	struct hdmi_any_infoframe any;
>  	struct hdmi_avi_infoframe avi;
>  	struct hdmi_spd_infoframe spd;
>  	struct hdmi_vendor_infoframe vendor;
> +	struct hdmi_hdmi_infoframe hdmi;
>  	struct hdmi_audio_infoframe audio;
>  };
>  
> -- 
> 1.8.3.1
> 
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-- 
Ville Syrjälä
Intel OTC