Re: [PATCH 06/18] video/hdmi: Handle the MPEG Source infoframe

Hans Verkuil
2018-09-21T08:28:09Z

On 09/20/18 20:51, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Add the code to deal with the MPEG source infoframe.
>
> Blindly typed from the spec, and totally untested.

I'm not sure this patch should be added at all. The CTA-861-G spec (section 6.7)
says that the implementation of this infoframe is not recommended due to unresolved
issues.

I don't think I've ever seen it either.

It obviously doesn't hurt to have this code, but I prefer to wait until there
are devices that actively set/use this infoframe.

Regards,

Hans

>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Cc: linux-media@vger.kernel.org
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/video/hdmi.c | 229 +++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/hdmi.h | 27 ++++++
> 2 files changed, 256 insertions(+)
>
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 9507f668a569..3d24c7746c51 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -706,6 +706,131 @@ hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> return hdmi_vendor_any_infoframe_pack_only(frame, buffer, size);
> }
>
> +/**
> + * hdmi_mpeg_source_infoframe_init() - initialize an HDMI MPEG Source infoframe
> + * @frame: HDMI MPEG Source infoframe
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_mpeg_source_infoframe_init(struct hdmi_mpeg_source_infoframe *frame)
> +{
> + memset(frame, 0, sizeof(*frame));
> +
> + frame->type = HDMI_INFOFRAME_TYPE_MPEG_SOURCE;
> + frame->version = 1;
> + frame->length = HDMI_MPEG_SOURCE_INFOFRAME_SIZE;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(hdmi_mpeg_source_infoframe_init);
> +
> +static int hdmi_mpeg_source_infoframe_check_only(const struct hdmi_mpeg_source_infoframe *frame)
> +{
> + if (frame->type != HDMI_INFOFRAME_TYPE_MPEG_SOURCE ||
> + frame->version != 1 ||
> + frame->length != HDMI_MPEG_SOURCE_INFOFRAME_SIZE)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +/**
> + * hdmi_mpeg_source_infoframe_check() - Check and check a HDMI MPEG Source infoframe
> + * @frame: HDMI MPEG Source infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_mpeg_source_infoframe_check(struct hdmi_mpeg_source_infoframe *frame)
> +{
> + return hdmi_mpeg_source_infoframe_check_only(frame);
> +}
> +EXPORT_SYMBOL(hdmi_mpeg_source_infoframe_check);
> +
> +/**
> + * hdmi_mpeg_source_infoframe_pack_only() - write HDMI MPEG Source infoframe to binary buffer
> + * @frame: HDMI MPEG Source 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_mpeg_source_infoframe_pack_only(const struct hdmi_mpeg_source_infoframe *frame,
> + void *buffer, size_t size)
> +{
> + u8 *ptr = buffer;
> + size_t length;
> + int ret;
> +
> + ret = hdmi_mpeg_source_infoframe_check_only(frame);
> + if (ret)
> + return ret;
> +
> + 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 */
> +
> + /* start infoframe payload */
> + ptr += HDMI_INFOFRAME_HEADER_SIZE;
> +
> + ptr[0] = frame->mpeg_bit_rate >> 0;
> + ptr[1] = frame->mpeg_bit_rate >> 8;
> + ptr[2] = frame->mpeg_bit_rate >> 16;
> + ptr[3] = frame->mpeg_bit_rate >> 24;
> + ptr[4] = (frame->field_repeat << 4) | frame->mpeg_frame;
> +
> + hdmi_infoframe_set_checksum(buffer, length);
> +
> + return length;
> +}
> +EXPORT_SYMBOL(hdmi_mpeg_source_infoframe_pack_only);
> +
> +/**
> + * hdmi_mpeg_source_infoframe_pack() - Check and check a HDMI MPEG Source infoframe,
> + * and write it to binary buffer
> + * @frame: HDMI MPEG Source infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which 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_mpeg_source_infoframe_pack(struct hdmi_mpeg_source_infoframe *frame,
> + void *buffer, size_t size)
> +{
> + int ret;
> +
> + ret = hdmi_mpeg_source_infoframe_check(frame);
> + if (ret)
> + return ret;
> +
> + return hdmi_mpeg_source_infoframe_pack_only(frame, buffer, size);
> +}
> +EXPORT_SYMBOL(hdmi_mpeg_source_infoframe_pack);
> +
> /**
> * hdmi_infoframe_check() - Check check a HDMI infoframe
> * @frame: HDMI infoframe
> @@ -727,6 +852,8 @@ hdmi_infoframe_check(union hdmi_infoframe *frame)
> return hdmi_audio_infoframe_check(&frame->audio);
> case HDMI_INFOFRAME_TYPE_VENDOR:
> return hdmi_vendor_any_infoframe_check(&frame->vendor);
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + return hdmi_mpeg_source_infoframe_check(&frame->mpeg_source);
> default:
> WARN(1, "Bad infoframe type %d\n", frame->any.type);
> return -EINVAL;
> @@ -770,6 +897,10 @@ hdmi_infoframe_pack_only(const union hdmi_infoframe *frame, void *buffer, size_t
> length = hdmi_vendor_any_infoframe_pack_only(&frame->vendor,
> buffer, size);
> break;
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + length = hdmi_mpeg_source_infoframe_pack_only(&frame->mpeg_source,
> + buffer, size);
> + break;
> default:
> WARN(1, "Bad infoframe type %d\n", frame->any.type);
> length = -EINVAL;
> @@ -816,6 +947,10 @@ hdmi_infoframe_pack(union hdmi_infoframe *frame,
> length = hdmi_vendor_any_infoframe_pack(&frame->vendor,
> buffer, size);
> break;
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + length = hdmi_mpeg_source_infoframe_pack(&frame->mpeg_source,
> + buffer, size);
> + break;
> default:
> WARN(1, "Bad infoframe type %d\n", frame->any.type);
> length = -EINVAL;
> @@ -838,6 +973,8 @@ static const char *hdmi_infoframe_type_get_name(enum hdmi_infoframe_type type)
> return "Source Product Description (SPD)";
> case HDMI_INFOFRAME_TYPE_AUDIO:
> return "Audio";
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + return "MPEG Source";
> }
> return "Reserved";
> }
> @@ -1349,6 +1486,46 @@ hdmi_vendor_any_infoframe_log(const char *level,
> }
> }
>
> +static const char *
> +hdmi_mpeg_frame_get_name(enum hdmi_mpeg_frame frame)
> +{
> + if (frame < 0 || frame > 3)
> + return "invalid";
> +
> + switch (frame) {
> + case HDMI_MPEG_FRAME_UNKNOWN:
> + return "Unknown";
> + case HDMI_MPEG_FRAME_I_PICTURE:
> + return "I Picture";
> + case HDMI_MPEG_FRAME_B_PICTURE:
> + return "B Picture";
> + case HDMI_MPEG_FRAME_P_PICTURE:
> + return "P Picture";
> + }
> + return "Reserved";
> +}
> +
> +/**
> + * hdmi_mpeg_source_infoframe_log() - log info of HDMI MPEG Source infoframe
> + * @level: logging level
> + * @dev: device
> + * @frame: HDMI MPEG Source infoframe
> + */
> +static void hdmi_mpeg_source_infoframe_log(const char *level,
> + struct device *dev,
> + const struct hdmi_mpeg_source_infoframe *frame)
> +{
> + hdmi_infoframe_log_header(level, dev,
> + (const struct hdmi_any_infoframe *)frame);
> +
> + hdmi_log(" MPEG bit rate: %d Hz\n",
> + frame->mpeg_bit_rate);
> + hdmi_log(" MPEG frame: %s\n",
> + hdmi_mpeg_frame_get_name(frame->mpeg_frame));
> + hdmi_log(" field repeat: %s\n",
> + frame->field_repeat ? "Yes" : "No");
> +}
> +
> /**
> * hdmi_infoframe_log() - log info of HDMI infoframe
> * @level: logging level
> @@ -1372,6 +1549,9 @@ void hdmi_infoframe_log(const char *level,
> case HDMI_INFOFRAME_TYPE_VENDOR:
> hdmi_vendor_any_infoframe_log(level, dev, &frame->vendor);
> break;
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + hdmi_mpeg_source_infoframe_log(level, dev, &frame->mpeg_source);
> + break;
> }
> }
> EXPORT_SYMBOL(hdmi_infoframe_log);
> @@ -1614,6 +1794,52 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
> return 0;
> }
>
> +/**
> + * hdmi_mpeg_source_infoframe_unpack() - unpack binary buffer to a HDMI MPEG Source infoframe
> + * @frame: HDMI MPEG Source infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
> + *
> + * Unpacks the information contained in binary @buffer into a structured
> + * @frame of the HDMI MPEG Source information frame.
> + * Also verifies the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +static int hdmi_mpeg_source_infoframe_unpack(struct hdmi_mpeg_source_infoframe *frame,
> + const void *buffer, size_t size)
> +{
> + const u8 *ptr = buffer;
> + int ret;
> +
> + if (size < HDMI_INFOFRAME_SIZE(MPEG_SOURCE))
> + return -EINVAL;
> +
> + if (ptr[0] != HDMI_INFOFRAME_TYPE_MPEG_SOURCE ||
> + ptr[1] != 1 ||
> + ptr[2] != HDMI_MPEG_SOURCE_INFOFRAME_SIZE) {
> + return -EINVAL;
> + }
> +
> + if (hdmi_infoframe_checksum(buffer, HDMI_INFOFRAME_SIZE(MPEG_SOURCE)) != 0)
> + return -EINVAL;
> +
> + ret = hdmi_mpeg_source_infoframe_init(frame);
> + if (ret)
> + return ret;
> +
> + ptr += HDMI_INFOFRAME_HEADER_SIZE;
> +
> + frame->mpeg_bit_rate =
> + (ptr[0] << 0) | (ptr[1] << 8) |
> + (ptr[2] << 16) | (ptr[3] << 24);
> + frame->mpeg_frame = ptr[4] & 0x3;
> + frame->field_repeat = ptr[4] & 0x10;
> +
> + return 0;
> +}
> +
> /**
> * hdmi_infoframe_unpack() - unpack binary buffer to a HDMI infoframe
> * @frame: HDMI infoframe
> @@ -1649,6 +1875,9 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
> case HDMI_INFOFRAME_TYPE_VENDOR:
> ret = hdmi_vendor_any_infoframe_unpack(&frame->vendor, buffer, size);
> break;
> + case HDMI_INFOFRAME_TYPE_MPEG_SOURCE:
> + ret = hdmi_mpeg_source_infoframe_unpack(&frame->mpeg_source, buffer, size);
> + break;
> default:
> ret = -EINVAL;
> break;
> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> index 80521d9591a1..2c9322f7538d 100644
> --- a/include/linux/hdmi.h
> +++ b/include/linux/hdmi.h
> @@ -47,6 +47,7 @@ enum hdmi_infoframe_type {
> HDMI_INFOFRAME_TYPE_AVI = 0x82,
> HDMI_INFOFRAME_TYPE_SPD = 0x83,
> HDMI_INFOFRAME_TYPE_AUDIO = 0x84,
> + HDMI_INFOFRAME_TYPE_MPEG_SOURCE = 0x85,
> };
>
> #define HDMI_IEEE_OUI 0x000c03
> @@ -55,6 +56,7 @@ enum hdmi_infoframe_type {
> #define HDMI_AVI_INFOFRAME_SIZE 13
> #define HDMI_SPD_INFOFRAME_SIZE 25
> #define HDMI_AUDIO_INFOFRAME_SIZE 10
> +#define HDMI_MPEG_SOURCE_INFOFRAME_SIZE 10
>
> #define HDMI_INFOFRAME_SIZE(type) \
> (HDMI_INFOFRAME_HEADER_SIZE + HDMI_ ## type ## _INFOFRAME_SIZE)
> @@ -337,6 +339,29 @@ union hdmi_vendor_any_infoframe {
> struct hdmi_vendor_infoframe hdmi;
> };
>
> +enum hdmi_mpeg_frame {
> + HDMI_MPEG_FRAME_UNKNOWN,
> + HDMI_MPEG_FRAME_I_PICTURE,
> + HDMI_MPEG_FRAME_B_PICTURE,
> + HDMI_MPEG_FRAME_P_PICTURE,
> +};
> +
> +struct hdmi_mpeg_source_infoframe {
> + enum hdmi_infoframe_type type;
> + unsigned char version;
> + unsigned char length;
> + unsigned int mpeg_bit_rate;
> + enum hdmi_mpeg_frame mpeg_frame;
> + bool field_repeat;
> +};
> +
> +int hdmi_mpeg_source_infoframe_init(struct hdmi_mpeg_source_infoframe *frame);
> +ssize_t hdmi_mpeg_source_infoframe_pack(struct hdmi_mpeg_source_infoframe *frame,
> + void *buffer, size_t size);
> +ssize_t hdmi_mpeg_source_infoframe_pack_only(const struct hdmi_mpeg_source_infoframe *frame,
> + void *buffer, size_t size);
> +int hdmi_mpeg_source_infoframe_check(struct hdmi_mpeg_source_infoframe *frame);
> +
> /**
> * union hdmi_infoframe - overall union of all abstract infoframe representations
> * @any: generic infoframe
> @@ -344,6 +369,7 @@ union hdmi_vendor_any_infoframe {
> * @spd: spd infoframe
> * @vendor: union of all vendor infoframes
> * @audio: audio infoframe
> + * @mpeg_source: mpeg source infoframe
> *
> * This is used by the generic pack function. This works since all infoframes
> * have the same header which also indicates which type of infoframe should be
> @@ -355,6 +381,7 @@ union hdmi_infoframe {
> struct hdmi_spd_infoframe spd;
> union hdmi_vendor_any_infoframe vendor;
> struct hdmi_audio_infoframe audio;
> + struct hdmi_mpeg_source_infoframe mpeg_source;
> };
>
> ssize_t hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer,
>

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