diff --git a/src/soc/intel/skylake/vr_config.c b/src/soc/intel/skylake/vr_config.c
index 121a344..fc23640 100644
--- a/src/soc/intel/skylake/vr_config.c
+++ b/src/soc/intel/skylake/vr_config.c
@@ -92,113 +92,139 @@
 {
 	const uint16_t tdp = cpu_get_power_max();
 
-	static uint16_t mch_id = 0, igd_id = 0, lpc_id = 0;
+	static uint16_t mch_id = 0, igd_id = 0;
 	if (!mch_id) {
 		struct device *dev = pcidev_path_on_root(SA_DEVFN_ROOT);
-		mch_id = pci_read_config16(dev, PCI_DEVICE_ID);
+		mch_id = dev ? pci_read_config16(dev, PCI_DEVICE_ID) : 0xffff;
 	}
 	if (!igd_id) {
 		struct device *dev = pcidev_path_on_root(SA_DEVFN_IGD);
-		if (dev)
-			igd_id = pci_read_config16(dev, PCI_DEVICE_ID);
-		else
-			igd_id = 0xffff;
-	}
-	if (!lpc_id) {
-		struct device *dev = pcidev_path_on_root(PCH_DEVFN_LPC);
-		lpc_id = pci_read_config16(dev, PCI_DEVICE_ID);
+		igd_id = dev ? pci_read_config16(dev, PCI_DEVICE_ID) : 0xffff;
 	}
 
 	/*
 	 * Iccmax table from Doc #559100 Section 7.2 DC Specifications, the
 	 * Iccmax is the same among KBL-Y but KBL-U/R.
 	 * Addendum for AML-Y #594883, IccMax for IA core is 28A.
-	 * KBL-S #335195, KBL-H #335190
-	 * +----------------+-------------+---------------+------+-----+
-	 * | Domain/Setting |  SA         |  IA           | GTUS | GTS |
-	 * +----------------+-------------+---------------+------+-----+
-	 * | IccMax(KBL-S)  | 11.1A       | 100A          | 48A  | 48A |
-	 * |                |             | ...           | 45A  | 45A |
-	 * |                |             | 40A           | 35A  | 35A |
-	 * +----------------+-------------+---------------+------+-----+
-	 * | IccMax(KBL-H)  | 11.1A (45W) | 68A           | 55A  | 55A |
-	 * |                | 6.6A  (18W) | 60A           |      |     |
-	 * +----------------+-------------+---------------+------+-----+
-	 * | IccMax(KBL-U/R)| 6A(U42)     | 64A(U42)      | 31A  | 31A |
-	 * |                | 4.5A(Others)| 29A(P/C)      |      |     |
-	 * |                |             | 32A(i3/i5)    |      |     |
-	 * +----------------+-------------+---------------+------+-----+
-	 * | IccMax(KBL-Y)  | 4.1A        | 24A           | 24A  | 24A |
-	 * +----------------+-------------+---------------+------+-----+
-	 * | IccMax(AML-Y)  | 4.1A        | 28A           | 24A  | 24A |
-	 * +----------------+-------------+---------------+------+-----+
+	 * KBL-S #335195, KBL-H #335190, SKL-S #332687, SKL-H #332986,
+	 * SKL-U/Y #332990
+	 *
+	 *   Platform             Segment           SA       IA      GT (GT/GTx)
+	 * ---------------------------------------------------------------------
+	 *   KBL/SKL-S            (95W) quad        11.1     100     45
+	 *   SKL-S                (80W) quad        11.1     82      45
+	 *   KBL/SKL-S            (65W) quad        11.1     79      45
+	 *   SKL-S                (45W) quad        11.1     70      0
+	 *   KBL/SKL-S            (35W) quad        11.1     66      35
+	 *   SKL-S                (25W) quad        11.1     55      35
+	 *
+	 *   KBL/SKL-S            (54W) dual        11.1     58      48
+	 *   KBL/SKL-S            (51W) dual        11.1     45      48
+	 *   KBL/SKL-S            (35W) dual        11.1     40      48
+	 *
+	 *   SKL-H + OPC          (65W) GT4 quad    8        74      105/24
+	 *   SKL-H + OPC          (45W) GT4 quad    8        74      94/20
+	 *   SKL-H + OPC          (35W) GT4 quad    8        66      94/20
+	 *
+	 *   SKL-H                (35W) GT2 dual    11.1     60      55
+	 *
+	 *   KBL/SKL-H            (45W) GT2 quad    11.1     68      55
+	 *   KBL-H                (18W) GT2 quad    6.6      60      55
+	 *
+	 *   SKL-U + OPC          (28W) GT3 dual    5.1      32      57/19
+	 *   SKL-U + OPC          (15W) GT3 dual    5.1      29      57/19
+	 *   SKL-U                (15W) GT2 dual    4.5      29      31
+	 *
+	 *   KBL-U/R + OPC        (28W) GT3 dual    5.1      32      57/19
+	 *   KBL-U/R + OPC        (15W) GT3 dual    5.1      32      57/19
+	 *
+	 *   KBL-U/R              (15W) GT2 quad    6        64      31
+	 *   KBL-U/R              (15W) GT1/2 dual  4.5      32      31
+	 *   KBL-U/R              (15W) GT2 quad    4.5      29      31
+	 *
+	 *   SKL/KBL-Y            (6W)              4.1      24      24
+	 *   SKL/KBL-Y            (4.5W)            4.1      24      24
 	 */
 
 	switch (mch_id) {
+	case PCI_DEVICE_ID_INTEL_SKL_ID_S_2: /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_S: {
-		uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(11.1),
-			VR_CFG_AMP(40),
-			VR_CFG_AMP(48),
-			VR_CFG_AMP(48),
-		};
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(11.1, 40, 48, 48);
 		if (tdp >= 54)
 			icc_max[VR_IA_CORE] = VR_CFG_AMP(58);
 		else if (tdp >= 51)
 			icc_max[VR_IA_CORE] = VR_CFG_AMP(45);
 
 		return icc_max[domain];
-
 	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_S_4:  /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_DT_2: /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_DT: {
-		uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(11.1),
-			VR_CFG_AMP(66),
-			VR_CFG_AMP(45),
-			VR_CFG_AMP(45),
-		};
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(11.1, 55, 45, 45);
 		if (tdp >= 91)
 			icc_max[VR_IA_CORE] = VR_CFG_AMP(100);
+		else if (tdp >= 80)
+			icc_max[VR_IA_CORE] = VR_CFG_AMP(82);
 		else if (tdp >= 65)
 			icc_max[VR_IA_CORE] = VR_CFG_AMP(79);
-		else if (tdp >= 35) {
-			icc_max[VR_GT_UNSLICED] = VR_CFG_AMP(35);
+		else if (tdp >= 45) {
+			icc_max[VR_IA_CORE] = VR_CFG_AMP(70);
+			icc_max[VR_GT_SLICED] = 0;
+			icc_max[VR_GT_UNSLICED] = 0;
+		} else if (tdp >= 25) {
+			if (tdp >= 35)
+				icc_max[VR_IA_CORE] = VR_CFG_AMP(66);
+
 			icc_max[VR_GT_SLICED] = VR_CFG_AMP(35);
+			icc_max[VR_GT_UNSLICED] = VR_CFG_AMP(35);
 		}
 
 		return icc_max[domain];
 	}
-	case PCI_DEVICE_ID_INTEL_KBL_ID_H: {
-		uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(6.6),
-			VR_CFG_AMP(60),
-			VR_CFG_AMP(55),
-			VR_CFG_AMP(55),
-		};
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_4: {
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(11.1, 60, 94, 20);
 		if (tdp >= 45) {
+			icc_max[VR_IA_CORE] = VR_CFG_AMP(74);
+			if (tdp >= 65) {
+				icc_max[VR_GT_SLICED] = VR_CFG_AMP(105);
+				icc_max[VR_GT_UNSLICED] = VR_CFG_AMP(24);
+			}
+		}
+		return icc_max[domain];
+	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_2:  /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_EM: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_KBL_ID_H: {
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(6.6, 60, 55, 55);
+		if (tdp >= 35) {
+			if (tdp >= 45)
+				icc_max[VR_IA_CORE] = VR_CFG_AMP(68);
+
 			icc_max[VR_SYSTEM_AGENT] = VR_CFG_AMP(11.1);
-			icc_max[VR_IA_CORE] = VR_CFG_AMP(68);
 		}
 
 		return icc_max[domain];
 	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_U: {
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(5.1, 29, 57, 19);
+		if (tdp >= 28)
+			icc_max[VR_IA_CORE] = VR_CFG_AMP(32);
+		else if (igd_id != PCI_DEVICE_ID_INTEL_SKL_GT3E_SULTM_1) {
+			const uint16_t icc_max_gt2[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_ICC(4.5, 29, 31, 31);
+
+			return icc_max_gt2[domain];
+		}
+		return icc_max[domain];
+	}
 	case PCI_DEVICE_ID_INTEL_KBL_U_R: {
-		static const uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(6),
-			VR_CFG_AMP(64),
-			VR_CFG_AMP(31),
-			VR_CFG_AMP(31),
-		};
+		const uint16_t icc_max[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_ICC(6, 64, 31, 31);
 		return icc_max[domain];
 	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_Y: /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_Y: {
-		uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(4.1),
-			VR_CFG_AMP(24),
-			VR_CFG_AMP(24),
-			VR_CFG_AMP(24),
-		};
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(4.1, 24, 24, 24);
 
 		if (igd_id == PCI_DEVICE_ID_INTEL_AML_GT2_ULX)
 			icc_max[VR_IA_CORE] = VR_CFG_AMP(28);
@@ -206,12 +232,7 @@
 		return icc_max[domain];
 	}
 	case PCI_DEVICE_ID_INTEL_KBL_ID_U: {
-		uint16_t icc_max[NUM_VR_DOMAINS] = {
-			VR_CFG_AMP(4.5),
-			VR_CFG_AMP(32),
-			VR_CFG_AMP(31),
-			VR_CFG_AMP(31),
-		};
+		uint16_t icc_max[NUM_VR_DOMAINS] = VR_CFG_ALL_DOMAINS_ICC(4.5, 32, 31, 31);
 
 		if ((igd_id == PCI_DEVICE_ID_INTEL_KBL_GT3E_SULTM_1) ||
 		    (igd_id == PCI_DEVICE_ID_INTEL_KBL_GT3E_SULTM_2))
@@ -220,7 +241,7 @@
 		return icc_max[domain];
 	}
 	default:
-		printk(BIOS_ERR, "ERROR: Unknown MCH in VR-config\n");
+		printk(BIOS_ERR, "ERROR: Unknown MCH (%u) in VR-config\n", mch_id);
 	}
 	return 0;
 }
@@ -231,62 +252,58 @@
 	static uint16_t mch_id = 0, igd_id = 0;
 	if (!mch_id) {
 		struct device *dev = pcidev_path_on_root(SA_DEVFN_ROOT);
-		mch_id = pci_read_config16(dev, PCI_DEVICE_ID);
+		mch_id = dev ? pci_read_config16(dev, PCI_DEVICE_ID) : 0xffff;
 	}
 	if (!igd_id) {
 		struct device *dev = pcidev_path_on_root(SA_DEVFN_IGD);
-		if (dev)
-			igd_id = pci_read_config16(dev, PCI_DEVICE_ID);
-		else
-			igd_id = 0xffff;
+		igd_id = dev ? pci_read_config16(dev, PCI_DEVICE_ID) : 0xffff;
 	}
 
 	switch (mch_id) {
-	case PCI_DEVICE_ID_INTEL_KBL_ID_S: /* fallthrough */
-	case PCI_DEVICE_ID_INTEL_KBL_ID_DT: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_S_2: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_S_4: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_KBL_ID_S:   /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_KBL_ID_DT:  /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_DT_2: {
-		static const uint16_t loadline[NUM_VR_DOMAINS] = {
-			VR_CFG_MOHMS(0), /* Not specified */
-			VR_CFG_MOHMS(2.1),
-			VR_CFG_MOHMS(3.1),
-			VR_CFG_MOHMS(3.1),
-		};
-
+		/* SA Loadline is not specified */
+		const uint16_t loadline[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_LOADLINE(0, 2.1, 3.1, 3.1);
 		return loadline[domain];
 	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_2:  /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_EM: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_H_4:  /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_H: {
-		static const uint16_t loadline[NUM_VR_DOMAINS] = {
-			VR_CFG_MOHMS(10),
-			VR_CFG_MOHMS(1.8),
-			VR_CFG_MOHMS(2.65),
-			VR_CFG_MOHMS(2.65),
-		};
+		const uint16_t loadline[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_LOADLINE(10, 1.8, 2.65, 2.65);
+
+		if (igd_id == PCI_DEVICE_ID_INTEL_SKL_GT4_SHALM) {
+			const uint16_t loadline_gt4[NUM_VR_DOMAINS] =
+					VR_CFG_ALL_DOMAINS_LOADLINE(6, 1.6, 1.4, 6);
+			return loadline_gt4[domain];
+		}
 
 		return loadline[domain];
 	}
+	case PCI_DEVICE_ID_INTEL_SKL_ID_Y: /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_Y: {
-		uint16_t loadline[NUM_VR_DOMAINS] = {
-			VR_CFG_MOHMS(18),
-			VR_CFG_MOHMS(5.9),
-			VR_CFG_MOHMS(5.7),
-			VR_CFG_MOHMS(5.7),
-		};
+		uint16_t loadline[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_LOADLINE(18, 5.9, 5.7, 5.7);
 
 		if (igd_id == PCI_DEVICE_ID_INTEL_AML_GT2_ULX)
 			loadline[VR_IA_CORE] = VR_CFG_MOHMS(4);
 
 		return loadline[domain];
 	}
-	case PCI_DEVICE_ID_INTEL_KBL_U_R: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_SKL_ID_U: /* fallthrough */
+	case PCI_DEVICE_ID_INTEL_KBL_U_R:  /* fallthrough */
 	case PCI_DEVICE_ID_INTEL_KBL_ID_U: {
-		uint16_t loadline[NUM_VR_DOMAINS] = {
-			VR_CFG_MOHMS(10.3),
-			VR_CFG_MOHMS(2.4),
-			VR_CFG_MOHMS(3.1),
-			VR_CFG_MOHMS(3.1),
-		};
+		uint16_t loadline[NUM_VR_DOMAINS] =
+				VR_CFG_ALL_DOMAINS_LOADLINE(10.3, 2.4, 3.1, 3.1);
 
-		if ((igd_id == PCI_DEVICE_ID_INTEL_KBL_GT3E_SULTM_1) ||
+		if ((igd_id == PCI_DEVICE_ID_INTEL_SKL_GT3E_SULTM_1) ||
+		    (igd_id == PCI_DEVICE_ID_INTEL_SKL_GT3E_SULTM_2) ||
+		    (igd_id == PCI_DEVICE_ID_INTEL_KBL_GT3E_SULTM_1) ||
 		    (igd_id == PCI_DEVICE_ID_INTEL_KBL_GT3E_SULTM_2)) {
 			loadline[VR_GT_UNSLICED] = VR_CFG_MOHMS(2);
 			loadline[VR_GT_SLICED] = VR_CFG_MOHMS(6);
@@ -295,7 +312,7 @@
 		return loadline[domain];
 	}
 	default:
-		printk(BIOS_ERR, "ERROR: Unknown MCH in VR-config\n");
+		printk(BIOS_ERR, "ERROR: Unknown MCH (%u) in VR-config\n", mch_id);
 	}
 	return 0;
 }