[Intel-gfx] [PATCH 2/2] drm/i915/bxt: eDP low vswing support

[Sivakumar Thulasimani]

Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>

On 9/18/2015 2:11 PM, Sonika Jindal wrote:
> Adding voltage swing table for edp to support low vswings.
>
> Signed-off-by: Sonika Jindal <sonika.jindal at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_ddi.c |   23 +++++++++++++++++++----
>   1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 0d9b304..17281bc 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -256,9 +256,6 @@ struct bxt_ddi_buf_trans {
>   	bool default_index; /* true if the entry represents default value */
>   };
>   
> -/* BSpec does not define separate vswing/pre-emphasis values for eDP.
> - * Using DP values for eDP as well.
> - */
>   static const struct bxt_ddi_buf_trans bxt_ddi_translations_dp[] = {
>   					/* Idx	NT mV diff	db  */
>   	{ 52,  0, 0, 128, true  },	/* 0:	400		0   */
> @@ -273,6 +270,20 @@ static const struct bxt_ddi_buf_trans bxt_ddi_translations_dp[] = {
>   	{ 154, 0x9A, 1, 128, false },	/* 9:	1200		0   */
>   };
>   
> +static const struct bxt_ddi_buf_trans bxt_ddi_translations_edp[] = {
> +					/* Idx	NT mV diff	db  */
> +	{ 26, 0, 0, 128, false },	/* 0:	200		0   */
> +	{ 38, 0, 0, 112, false },	/* 1:	200		1.5 */
> +	{ 48, 0, 0, 96,  false },	/* 2:	200		4   */
> +	{ 54, 0, 0, 69,  false },	/* 3:	200		6   */
> +	{ 32, 0, 0, 128, false },	/* 4:	250		0   */
> +	{ 48, 0, 0, 104, false },	/* 5:	250		1.5 */
> +	{ 54, 0, 0, 85,  false },	/* 6:	250		4   */
> +	{ 43, 0, 0, 128, false },	/* 7:	300		0   */
> +	{ 54, 0, 0, 101, false },	/* 8:	300		1.5 */
> +	{ 48, 0, 0, 128, false },	/* 9:	300		0   */
> +};
> +
>   /* BSpec has 2 recommended values - entries 0 and 8.
>    * Using the entry with higher vswing.
>    */
> @@ -2113,7 +2124,11 @@ static void bxt_ddi_vswing_sequence(struct drm_device *dev, u32 level,
>   	u32 n_entries, i;
>   	uint32_t val;
>   
> -	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
> +	if (type == INTEL_OUTPUT_EDP && dev_priv->edp_low_vswing) {
> +		n_entries = ARRAY_SIZE(bxt_ddi_translations_edp);
> +		ddi_translations = bxt_ddi_translations_edp;
> +	} else if (type == INTEL_OUTPUT_DISPLAYPORT
> +			|| type == INTEL_OUTPUT_EDP) {
>   		n_entries = ARRAY_SIZE(bxt_ddi_translations_dp);
>   		ddi_translations = bxt_ddi_translations_dp;
>   	} else if (type == INTEL_OUTPUT_HDMI) {

-- 
regards,
Sivakumar