drm/i915: Move intel_aux_ch() to intel_bios.c

From ICL onwards all the DDI/TypeC ports - even working in HDMI mode -
need to know their corresponding AUX channel, so move the corresponding
helper to a common place.

No functional change.

v4:
- Fix 'no space is necessary after a cast' checkpatch warn.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181101140427.31026-2-imre.deak@intel.com

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 5fa2133f801d..0ad2304457ab 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -2159,3 +2159,48 @@ intel_bios_is_lspcon_present(struct drm_i915_private *dev_priv,
 
 	return false;
 }
+
+enum aux_ch intel_aux_ch(struct drm_i915_private *dev_priv, enum port port)
+{
+	const struct ddi_vbt_port_info *info =
+		&dev_priv->vbt.ddi_port_info[port];
+	enum aux_ch aux_ch;
+
+	if (!info->alternate_aux_channel) {
+		aux_ch = (enum aux_ch)port;
+
+		DRM_DEBUG_KMS("using AUX %c for port %c (platform default)\n",
+			      aux_ch_name(aux_ch), port_name(port));
+		return aux_ch;
+	}
+
+	switch (info->alternate_aux_channel) {
+	case DP_AUX_A:
+		aux_ch = AUX_CH_A;
+		break;
+	case DP_AUX_B:
+		aux_ch = AUX_CH_B;
+		break;
+	case DP_AUX_C:
+		aux_ch = AUX_CH_C;
+		break;
+	case DP_AUX_D:
+		aux_ch = AUX_CH_D;
+		break;
+	case DP_AUX_E:
+		aux_ch = AUX_CH_E;
+		break;
+	case DP_AUX_F:
+		aux_ch = AUX_CH_F;
+		break;
+	default:
+		MISSING_CASE(info->alternate_aux_channel);
+		aux_ch = AUX_CH_A;
+		break;
+	}
+
+	DRM_DEBUG_KMS("using AUX %c for port %c (VBT)\n",
+		      aux_ch_name(aux_ch), port_name(port));
+
+	return aux_ch;
+}