Commit 054ce0bc authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/dp: add DP 2.0 UHBR link rate and bw code conversions 



The bw code equals link_rate / 0.27 Gbps only for 8b/10b link
rates. Handle DP 2.0 UHBR rates as special cases, though this is not
pretty.

Cc: dri-devel@lists.freedesktop.org
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/cab4edda8834d6b4db610fabb5e1f1f18ae33c2c.1631191763.git.jani.nikula@intel.com
parent 641dd82f

drivers/gpu/drm/drm_dp_helper.c

+22 −4
Original line number Diff line number Diff line
@@ -207,16 +207,34 @@ EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); 


u8 drm_dp_link_rate_to_bw_code(int link_rate)

{

	switch (link_rate) {

	case 1000000:

		return DP_LINK_BW_10;

	case 1350000:

		return DP_LINK_BW_13_5;

	case 2000000:

		return DP_LINK_BW_20;

	default:

		/* Spec says link_bw = link_rate / 0.27Gbps */

		return link_rate / 27000;

	}

}

EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);



int drm_dp_bw_code_to_link_rate(u8 link_bw)

{

	switch (link_bw) {

	case DP_LINK_BW_10:

		return 1000000;

	case DP_LINK_BW_13_5:

		return 1350000;

	case DP_LINK_BW_20:

		return 2000000;

	default:

		/* Spec says link_rate = link_bw * 0.27Gbps */

		return link_bw * 27000;

	}

}

EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);



#define AUX_RETRY_INTERVAL 500 /* us */