Re: [PATCH 1/2] drm/edid: add #defines and helpers for ELD

Rodrigo Vivi
2014-11-04T23:53:41Z

On Tue, Oct 28, 2014 at 7:20 AM, Jani Nikula <jani.nikula@intel.com> wrote:
> In the interest of reducing magic numbers and having to cross check with
> the specs all the time.
>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
> include/drm/drm_edid.h | 102 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 102 insertions(+)
>
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index b96031d947a0..c2f1bfa22010 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -207,6 +207,61 @@ struct detailed_timing {
> #define DRM_EDID_HDMI_DC_30 (1 << 4)
> #define DRM_EDID_HDMI_DC_Y444 (1 << 3)
>
> +/* ELD Header Block */
> +#define DRM_ELD_HEADER_BLOCK_SIZE 4
> +
> +#define DRM_ELD_VER 0
> +# define DRM_ELD_VER_SHIFT 3
> +# define DRM_ELD_VER_MASK (0x1f << 3)
> +
> +#define DRM_ELD_BASELINE_ELD_LEN 2 /* in dwords! */
> +
> +/* ELD Baseline Block for ELD_Ver == 2 */
> +#define DRM_ELD_CEA_EDID_VER_MNL 4
Oh, this VER_MNL name confused me a lot during review.... confusing
with MNN_SHIFT.
But since I don't have a better suggestions nevermind ;)

> +# define DRM_ELD_CEA_EDID_VER_SHIFT 5
> +# define DRM_ELD_CEA_EDID_VER_MASK (7 << 5)
> +# define DRM_ELD_CEA_EDID_VER_NONE (0 << 5)
> +# define DRM_ELD_CEA_EDID_VER_CEA861 (1 << 5)
> +# define DRM_ELD_CEA_EDID_VER_CEA861A (2 << 5)
> +# define DRM_ELD_CEA_EDID_VER_CEA861BCD (3 << 5)
> +# define DRM_ELD_MNL_SHIFT 0
> +# define DRM_ELD_MNL_MASK (0x1f << 0)
> +
> +#define DRM_ELD_SAD_COUNT_CONN_TYPE 5
> +# define DRM_ELD_SAD_COUNT_SHIFT 4
> +# define DRM_ELD_SAD_COUNT_MASK (0xf << 4)
> +# define DRM_ELD_CONN_TYPE_SHIFT 2
> +# define DRM_ELD_CONN_TYPE_MASK (3 << 2)
> +# define DRM_ELD_CONN_TYPE_HDMI (0 << 2)
> +# define DRM_ELD_CONN_TYPE_DP (1 << 2)
> +# define DRM_ELD_SUPPORTS_AI (1 << 1)
> +# define DRM_ELD_SUPPORTS_HDCP (1 << 0)
> +
> +#define DRM_ELD_AUD_SYNCH_DELAY 6 /* in units of 2 ms */
> +# define DRM_ELD_AUD_SYNCH_DELAY_MAX 0xfa /* 500 ms */
> +
> +#define DRM_ELD_SPEAKER 7
> +# define DRM_ELD_SPEAKER_RLRC (1 << 6)
> +# define DRM_ELD_SPEAKER_FLRC (1 << 5)
> +# define DRM_ELD_SPEAKER_RC (1 << 4)
> +# define DRM_ELD_SPEAKER_RLR (1 << 3)
> +# define DRM_ELD_SPEAKER_FC (1 << 2)
> +# define DRM_ELD_SPEAKER_LFE (1 << 1)
> +# define DRM_ELD_SPEAKER_FLR (1 << 0)
> +
> +#define DRM_ELD_PORT_ID 8 /* offsets 8..15 inclusive */
> +# define DRM_ELD_PORT_ID_LEN 8
> +
> +#define DRM_ELD_MANUFACTURER_NAME0 16
> +#define DRM_ELD_MANUFACTURER_NAME1 17
> +
> +#define DRM_ELD_PRODUCT_CODE0 18
> +#define DRM_ELD_PRODUCT_CODE1 19
> +
> +#define DRM_ELD_MONITOR_NAME_STRING 20 /* offsets 20..(20+mnl-1) inclusive */
> +
> +#define DRM_ELD_CEA_SAD(mnl, sad) (20 + (mnl) + 3 * (sad))
> +
> struct edid {
> u8 header[8];
> /* Vendor & product info */
> @@ -279,4 +334,51 @@ int
> drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
> const struct drm_display_mode *mode);
>
> +/**
> + * drm_eld_mnl - Get ELD monitor name length in bytes.
> + * @eld: pointer to an eld memory structure with mnl set
> + */
> +static inline int drm_eld_mnl(const uint8_t *eld)
> +{
> + return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
> +}
> +
> +/**
> + * drm_eld_sad_count - Get ELD SAD count.
> + * @eld: pointer to an eld memory structure with sad_count set
> + */
> +static inline int drm_eld_sad_count(const uint8_t *eld)
> +{
> + return (eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_SAD_COUNT_MASK) >>
> + DRM_ELD_SAD_COUNT_SHIFT;
> +}
> +
> +/**
> + * drm_eld_calc_baseline_block_size - Calculate baseline block size in bytes
> + * @eld: pointer to an eld memory structure with mnl and sad_count set
> + *
> + * This is a helper for determining the payload size of the baseline block, in
> + * bytes, for e.g. setting the Baseline_ELD_Len field in the ELD header block.
> + */
> +static inline int drm_eld_calc_baseline_block_size(const uint8_t *eld)
> +{
> + return DRM_ELD_MONITOR_NAME_STRING - DRM_ELD_HEADER_BLOCK_SIZE +
> + drm_eld_mnl(eld) + drm_eld_sad_count(eld) * 3;
> +}
> +
> +/**
> + * drm_eld_size - Get ELD size in bytes
> + * @eld: pointer to a complete eld memory structure
> + *
> + * The returned value does not include the vendor block. It's vendor specific,
> + * and comprises of the remaining bytes in the ELD memory buffer after
> + * drm_eld_size() bytes of header and baseline block.
> + *
> + * The returned value is guaranteed to be a multiple of 4.
> + */
> +static inline int drm_eld_size(const uint8_t *eld)
> +{
> + return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
> +}
> +
> #endif /* __DRM_EDID_H__ */
> --
> 2.1.1
>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

--
Rodrigo Vivi
Blog: http://blog.vivi.eng.br
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