drm/i915/dg1: gmbus pin mapping

Add tables to map the GMBUS pin pairs to GPIO registers and port to DDC.
From spec we have registers GPIO_CTL[1-4], so we should not do the 4->9
mapping as in ICL/TGL.

The values for VBT seem wrong in BSpec. For the current boards we
actually have a 1:1 mapping.

BSpec: 49311, 49945, 20124

Cc: Aditya Swarup <aditya.swarup@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007002210.3678024-5-lucas.demarchi@intel.com

drivers/gpu/drm/i915/display/intel_bios.c

@@ -1602,7 +1602,9 @@ static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin)
 	const u8 *ddc_pin_map;
 	int n_entries;
 
-	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP) {
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1) {
+		return vbt_pin;
+	} else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP) {
 		ddc_pin_map = icp_ddc_pin_map;
 		n_entries = ARRAY_SIZE(icp_ddc_pin_map);
 	} else if (HAS_PCH_CNP(dev_priv)) {

drivers/gpu/drm/i915/display/intel_gmbus.c

@@ -90,11 +90,20 @@ static const struct gmbus_pin gmbus_pins_icp[] = {
 	[GMBUS_PIN_14_TC6_TGP] = { "tc6", GPIOO },
 };
 
+static const struct gmbus_pin gmbus_pins_dg1[] = {
+	[GMBUS_PIN_1_BXT] = { "dpa", GPIOB },
+	[GMBUS_PIN_2_BXT] = { "dpb", GPIOC },
+	[GMBUS_PIN_3_BXT] = { "dpc", GPIOD },
+	[GMBUS_PIN_4_CNP] = { "dpd", GPIOE },
+};
+
 /* pin is expected to be valid */
 static const struct gmbus_pin *get_gmbus_pin(struct drm_i915_private *dev_priv,
 					     unsigned int pin)
 {
-	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1)
+		return &gmbus_pins_dg1[pin];
+	else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
 		return &gmbus_pins_icp[pin];
 	else if (HAS_PCH_CNP(dev_priv))
 		return &gmbus_pins_cnp[pin];
@@ -113,7 +122,9 @@ bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
 {
 	unsigned int size;
 
-	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1)
+		size = ARRAY_SIZE(gmbus_pins_dg1);
+	else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
 		size = ARRAY_SIZE(gmbus_pins_icp);
 	else if (HAS_PCH_CNP(dev_priv))
 		size = ARRAY_SIZE(gmbus_pins_cnp);

drivers/gpu/drm/i915/display/intel_hdmi.c

@@ -3140,6 +3140,11 @@ static u8 rkl_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
 	return GMBUS_PIN_1_BXT + phy;
 }
 
+static u8 dg1_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
+{
+	return intel_port_to_phy(dev_priv, port) + 1;
+}
+
 static u8 g4x_port_to_ddc_pin(struct drm_i915_private *dev_priv,
 			      enum port port)
 {
@@ -3177,7 +3182,9 @@ static u8 intel_hdmi_ddc_pin(struct intel_encoder *encoder)
 		return ddc_pin;
 	}
 
-	if (IS_ROCKETLAKE(dev_priv))
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1)
+		ddc_pin = dg1_port_to_ddc_pin(dev_priv, port);
+	else if (IS_ROCKETLAKE(dev_priv))
 		ddc_pin = rkl_port_to_ddc_pin(dev_priv, port);
 	else if (HAS_PCH_MCC(dev_priv))
 		ddc_pin = mcc_port_to_ddc_pin(dev_priv, port);