[Intel-gfx] [PATCH] drm/i915/cnl: Map VBT DDC Pin to BSpec DDC Pin.

[Rodrigo Vivi]

Starting on CNL we now need to map VBT DDC Pin to
BSPec DDC Pin values. Not a direct translation anymore.

According to VBT
Block 2 (General Bytes Definition)
DDC Bus

+----------+-----------+--------------------+
| DDI Type | VBT Value | Bspec Mapped Value |
+----------+-----------+--------------------+
| DDI-B    | 0x1       | 0x1                |
| DDI-C    | 0x2       | 0x2                |
| DDI-D    | 0x3       | 0x4                |
| DDI-F    | 0x4       | 0x3                |
+----------+-----------+--------------------+

v2: Move defines to a better place.
    This is actually CNL_PCH not CNL only.
v3: Accepting Ville's suggestions: enums and array to
    to make this future proof.

Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
Cc: Clinton Taylor <clinton.a.taylor at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_bios.c     | 26 ++++++++++++++++----------
 drivers/gpu/drm/i915/intel_vbt_defs.h | 15 +++++++++++++++
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index dc4fad30bf4f..79638308664c 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1071,6 +1071,21 @@ static void sanitize_aux_ch(struct drm_i915_private *dev_priv,
 	}
 }
 
+static const enum bspec_gmbus_pin cnp_ddc_pin_map[] = {
+	[DDC_BUS_DDI_B] = GMBUS_PIN_1,
+	[DDC_BUS_DDI_C] = GMBUS_PIN_2,
+	[DDC_BUS_DDI_D] = GMBUS_PIN_4,
+	[DDC_BUS_DDI_F] = GMBUS_PIN_3,
+};
+
+static u8 get_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin)
+{
+	if (HAS_PCH_CNP(dev_priv))
+		return cnp_ddc_pin_map[vbt_pin];
+
+	return vbt_pin;
+}
+
 static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
 			   u8 bdb_version)
 {
@@ -1164,16 +1179,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
 		DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
 
 	if (is_dvi) {
-		info->alternate_ddc_pin = ddc_pin;
-
-		/*
-		 * All VBTs that we got so far for B Stepping has this
-		 * information wrong for Port D. So, let's just ignore for now.
-		 */
-		if (IS_CNL_REVID(dev_priv, CNL_REVID_B0, CNL_REVID_B0) &&
-		    port == PORT_D) {
-			info->alternate_ddc_pin = 0;
-		}
+		info->alternate_ddc_pin = get_ddc_pin(dev_priv, ddc_pin);
 
 		sanitize_ddc_pin(dev_priv, port);
 	}
diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h
index 7e2a96712d07..dfc9f7a43668 100644
--- a/drivers/gpu/drm/i915/intel_vbt_defs.h
+++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
@@ -308,6 +308,21 @@ struct bdb_general_features {
 
 #define LEGACY_CHILD_DEVICE_CONFIG_SIZE		33
 
+/* DDC Bus DDI Type 155+ */
+enum vbt_gmbus_ddi {
+	DDC_BUS_DDI_B = 0x1,
+	DDC_BUS_DDI_C,
+	DDC_BUS_DDI_D,
+	DDC_BUS_DDI_F,
+};
+
+enum bspec_gmbus_pin {
+	GMBUS_PIN_1 = 0x1,
+	GMBUS_PIN_2,
+	GMBUS_PIN_3,
+	GMBUS_PIN_4,
+};
+
 /*
  * The child device config, aka the display device data structure, provides a
  * description of a port and its configuration on the platform.
-- 
2.13.5