[Intel-gfx] [PATCH] drm/i915/display/ehl: Add HBR2 and HBR3 voltage swing table

[Matt Roper]

On Wed, Feb 05, 2020 at 12:56:47PM -0800, José Roberto de Souza wrote:
> EHL only differs from ICL on the voltage swing table for HBR2 and
> HBR3.
> 
> BSpec: 21257
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 34 +++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 1ab638e17046..3060cc37e1d2 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -568,6 +568,20 @@ static const struct cnl_ddi_buf_trans icl_combo_phy_ddi_translations_hdmi[] = {
>  	{ 0x6, 0x7F, 0x35, 0x00, 0x0A },	/* 600   850      3.0   */
>  };
>  
> +static const struct cnl_ddi_buf_trans ehl_combo_phy_ddi_translations_hbr2_hbr3[] = {
> +						/* NT mV Trans mV db    */
> +	{ 0xA, 0x33, 0x3F, 0x00, 0x00 },	/* 350   350      0.0   */
> +	{ 0xA, 0x47, 0x36, 0x00, 0x09 },	/* 350   500      3.1   */
> +	{ 0xC, 0x64, 0x30, 0x00, 0x0F },	/* 350   700      6.0   */
> +	{ 0x6, 0x7F, 0x2C, 0x00, 0x13 },	/* 350   900      8.2   */
> +	{ 0xA, 0x46, 0x3F, 0x00, 0x00 },	/* 500   500      0.0   */
> +	{ 0xC, 0x64, 0x36, 0x00, 0x09 },	/* 500   700      2.9   */
> +	{ 0x6, 0x7F, 0x30, 0x00, 0x0F },	/* 500   900      5.1   */
> +	{ 0xC, 0x61, 0x3F, 0x00, 0x00 },	/* 650   700      0.6   */
> +	{ 0x6, 0x7F, 0x37, 0x00, 0x08 },	/* 600   900      3.5   */
> +	{ 0x6, 0x7F, 0x3F, 0x00, 0x00 },	/* 900   900      0.0   */
> +};
> +
>  struct icl_mg_phy_ddi_buf_trans {
>  	u32 cri_txdeemph_override_5_0;
>  	u32 cri_txdeemph_override_11_6;
> @@ -929,6 +943,18 @@ icl_get_combo_buf_trans(struct drm_i915_private *dev_priv, int type, int rate,
>  	return icl_combo_phy_ddi_translations_dp_hbr2;
>  }
>  
> +static const struct cnl_ddi_buf_trans *
> +ehl_get_combo_buf_trans(struct drm_i915_private *dev_priv, int type, int rate,
> +			int *n_entries)
> +{
> +	if (type == INTEL_OUTPUT_DP && rate > 270000) {
> +		*n_entries = ARRAY_SIZE(ehl_combo_phy_ddi_translations_hbr2_hbr3);
> +		return ehl_combo_phy_ddi_translations_hbr2_hbr3;
> +	}
> +
> +	return icl_get_combo_buf_trans(dev_priv, type, rate, n_entries);
> +}
> +
>  static const struct cnl_ddi_buf_trans *
>  tgl_get_combo_buf_trans(struct drm_i915_private *dev_priv, int type, int rate,
>  			int *n_entries)
> @@ -2415,7 +2441,10 @@ u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
>  		else
>  			n_entries = ARRAY_SIZE(tgl_dkl_phy_dp_ddi_trans);
>  	} else if (INTEL_GEN(dev_priv) == 11) {
> -		if (intel_phy_is_combo(dev_priv, phy))
> +		if (IS_ELKHARTLAKE(dev_priv))
> +			ehl_get_combo_buf_trans(dev_priv, encoder->type,
> +						intel_dp->link_rate, &n_entries);

Might be more natural to promote this to the outer if/else (before the
general gen11 case).

But your table matches the bspec and the logic looks correct, so either
way,

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>


> +		else if (intel_phy_is_combo(dev_priv, phy))
>  			icl_get_combo_buf_trans(dev_priv, encoder->type,
>  						intel_dp->link_rate, &n_entries);
>  		else
> @@ -2608,6 +2637,9 @@ static void icl_ddi_combo_vswing_program(struct drm_i915_private *dev_priv,
>  	if (INTEL_GEN(dev_priv) >= 12)
>  		ddi_translations = tgl_get_combo_buf_trans(dev_priv, type, rate,
>  							   &n_entries);
> +	else if (IS_ELKHARTLAKE(dev_priv))
> +		ddi_translations = ehl_get_combo_buf_trans(dev_priv, type, rate,
> +							   &n_entries);
>  	else
>  		ddi_translations = icl_get_combo_buf_trans(dev_priv, type, rate,
>  							   &n_entries);
> -- 
> 2.25.0
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795