Re: [PATCH 31/35] drm/i915/bios: Define VBT block 57 (Vswing PreEmphasis Table) contents

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 03 May 2024, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Define the contents of VBT block 57 (Vswing PreEmphasis Table).
>
> The contents is highly platform specific. The columns of the
> table corresponding to some set of PHY/etc registers. The rows
> corresponding to all legal vswing+pre-emphasis combinations
> (ie. should be 10 rows in each table). And each table
> corresponds to a platform specific (mostly undocumented)
> mapping based on link rate/eDP low-vswing/etc. parameters.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

I guess we should use this... but I'm not sure how.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_vbt_defs.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> index 50d0d96fca67..0e5a2bf429f4 100644
> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> @@ -184,6 +184,7 @@ enum bdb_block_id {
>  	BDB_MIPI_SEQUENCE		= 53, /* 177+ */
>  	BDB_RGB_PALETTE			= 54, /* 180+ */
>  	BDB_COMPRESSION_PARAMETERS	= 56, /* 213+ */
> +	BDB_VSWING_PREEMPH		= 57, /* 218+ */
>  	BDB_GENERIC_DTD			= 58, /* 229+ */
>  	BDB_SKIP			= 254, /* VBIOS only */
>  };
> @@ -1486,6 +1487,16 @@ struct bdb_compression_parameters {
>  	struct dsc_compression_parameters_entry data[16];
>  } __packed;
>  
> +/*
> + * Block 57 -  Vswing PreEmphasis Table
> + */
> +
> +struct bdb_vswing_preemph {
> +	u8 num_tables;
> +	u8 num_columns;
> +	u32 tables[];
> +} __packed;
> +
>  /*
>   * Block 58 - Generic DTD Block
>   */

-- 
Jani Nikula, Intel