drm/i915/adl_s: Add PCH support

Add support for Alderpoint(ADP) PCH used with Alderlake-S.

v2:
- Use drm_dbg_kms and drm_WARN_ON based on Jani's feedback.(aswarup)

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Caz Yokoyama <caz.yokoyama@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210125140753.347998-3-aditya.swarup@intel.com

drivers/gpu/drm/i915/intel_pch.c

@@ -128,6 +128,10 @@ intel_pch_type(const struct drm_i915_private *dev_priv, unsigned short id)
 		drm_dbg_kms(&dev_priv->drm, "Found Jasper Lake PCH\n");
 		drm_WARN_ON(&dev_priv->drm, !IS_JSL_EHL(dev_priv));
 		return PCH_JSP;
+	case INTEL_PCH_ADP_DEVICE_ID_TYPE:
+		drm_dbg_kms(&dev_priv->drm, "Found Alder Lake PCH\n");
+		drm_WARN_ON(&dev_priv->drm, !IS_ALDERLAKE_S(dev_priv));
+		return PCH_ADP;
 	default:
 		return PCH_NONE;
 	}
@@ -155,7 +159,9 @@ intel_virt_detect_pch(const struct drm_i915_private *dev_priv)
 	 * make an educated guess as to which PCH is really there.
 	 */
 
-	if (IS_TIGERLAKE(dev_priv) || IS_ROCKETLAKE(dev_priv))
+	if (IS_ALDERLAKE_S(dev_priv))
+		id = INTEL_PCH_ADP_DEVICE_ID_TYPE;
+	else if (IS_TIGERLAKE(dev_priv) || IS_ROCKETLAKE(dev_priv))
 		id = INTEL_PCH_TGP_DEVICE_ID_TYPE;
 	else if (IS_JSL_EHL(dev_priv))
 		id = INTEL_PCH_MCC_DEVICE_ID_TYPE;

drivers/gpu/drm/i915/intel_pch.h

@@ -26,6 +26,7 @@ enum intel_pch {
 	PCH_JSP,	/* Jasper Lake PCH */
 	PCH_MCC,        /* Mule Creek Canyon PCH */
 	PCH_TGP,	/* Tiger Lake PCH */
+	PCH_ADP,	/* Alder Lake PCH */
 
 	/* Fake PCHs, functionality handled on the same PCI dev */
 	PCH_DG1 = 1024,
@@ -53,12 +54,14 @@ enum intel_pch {
 #define INTEL_PCH_TGP2_DEVICE_ID_TYPE		0x4380
 #define INTEL_PCH_JSP_DEVICE_ID_TYPE		0x4D80
 #define INTEL_PCH_JSP2_DEVICE_ID_TYPE		0x3880
+#define INTEL_PCH_ADP_DEVICE_ID_TYPE		0x7A80
 #define INTEL_PCH_P2X_DEVICE_ID_TYPE		0x7100
 #define INTEL_PCH_P3X_DEVICE_ID_TYPE		0x7000
 #define INTEL_PCH_QEMU_DEVICE_ID_TYPE		0x2900 /* qemu q35 has 2918 */
 
 #define INTEL_PCH_TYPE(dev_priv)		((dev_priv)->pch_type)
 #define INTEL_PCH_ID(dev_priv)			((dev_priv)->pch_id)
+#define HAS_PCH_ADP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_ADP)
 #define HAS_PCH_DG1(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_DG1)
 #define HAS_PCH_JSP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_JSP)
 #define HAS_PCH_MCC(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_MCC)