intel/skylake: provide default VR configuration

FSP 1.8.0 will do nothing with the VR settings if VrConfigEnable is
non-zero. That behavior is not desired because it's not clear what
the behavior will be for various processor SKUs. Instead provide
default values for the VR config. Note that PSI3 and PSI4 are not
enabled for those defaults.

BUG=chrome-os-partner:48466
BRANCH=None
TEST=Built and booted glados.

Change-Id: I02cb5fbdd4549cc827a0b0e4006bc21da4593b55
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a68c53e0fdf15584270dfafc679a22319f497d17
Original-Change-Id: I82b1d1da2cfa3c83ccc6a981e30ffac6fb6c8c4b
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/318263
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/12983
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

4 files changed, 117 insertions, 22 deletions

diff --git a/src/soc/intel/skylake/Makefile.inc b/src/soc/intel/skylake/Makefile.inc
index 9c578c56c1..32076e74ab 100644
--- a/src/soc/intel/skylake/Makefile.inc
+++ b/src/soc/intel/skylake/Makefile.inc
@@ -58,6 +58,7 @@ ramstage-y += systemagent.c
 ramstage-y += tsc_freq.c
 ramstage-y += uart.c
 ramstage-$(CONFIG_UART_DEBUG) += uart_debug.c
+ramstage-y += vr_config.c
 ramstage-y += xhci.c
 
 smm-y += cpu_info.c
diff --git a/src/soc/intel/skylake/chip.c b/src/soc/intel/skylake/chip.c
index f4dc4a729f..b6485f7d94 100644
--- a/src/soc/intel/skylake/chip.c
+++ b/src/soc/intel/skylake/chip.c
@@ -359,28 +359,8 @@ void soc_silicon_init_params(SILICON_INIT_UPD *params)
 	else
 		params->PsfUnlock = 0;
 
-	for (i = 0; i < ARRAY_SIZE(config->domain_vr_config); i++) {
-		params->VrConfigEnable[i] =
-			config->domain_vr_config[i].vr_config_enable;
-		params->Psi1Threshold[i] =
-			config->domain_vr_config[i].psi1threshold;
-		params->Psi2Threshold[i] =
-			config->domain_vr_config[i].psi2threshold;
-		params->Psi3Threshold[i] =
-			config->domain_vr_config[i].psi3threshold;
-		params->Psi3Enable[i] =
-			config->domain_vr_config[i].psi3enable;
-		params->Psi4Enable[i] =
-			config->domain_vr_config[i].psi4enable;
-		params->ImonSlope[i] =
-			config->domain_vr_config[i].imon_slope;
-		params->ImonOffset[i] =
-			config->domain_vr_config[i].imon_offset;
-		params->IccMax[i] =
-			config->domain_vr_config[i].icc_max;
-		params->VrVoltageLimit[i] =
-			config->domain_vr_config[i].voltage_limit;
-	}
+	for (i = 0; i < ARRAY_SIZE(config->domain_vr_config); i++)
+		fill_vr_domain_config(params, i, &config->domain_vr_config[i]);
 
 	/* Show SPI controller if enabled in devicetree.cb */
 	dev = dev_find_slot(0, PCH_DEVFN_SPI);
diff --git a/src/soc/intel/skylake/include/soc/vr_config.h b/src/soc/intel/skylake/include/soc/vr_config.h
index 926ddf1a16..204b848a57 100644
--- a/src/soc/intel/skylake/include/soc/vr_config.h
+++ b/src/soc/intel/skylake/include/soc/vr_config.h
@@ -23,6 +23,8 @@
 #ifndef _SOC_VR_CONFIG_H_
 #define _SOC_VR_CONFIG_H_
 
+#include <fsp/soc_binding.h>
+
 struct vr_config {
 
 	/*
@@ -61,6 +63,8 @@ struct vr_config {
 	int voltage_limit;
 };
 
+#define VR_CFG_AMP(i) ((i) * 4)
+
 /* VrConfig Settings for 5 domains
  * 0 = System Agent, 1 = IA Core, 2 = Ring,
  * 3 = GT unsliced,  4 = GT sliced
@@ -74,4 +78,7 @@ enum vr_domain{
 	NUM_VR_DOMAINS
 };
 
+void fill_vr_domain_config(SILICON_INIT_UPD *params, int domain,
+				const struct vr_config *cfg);
+
 #endif
diff --git a/src/soc/intel/skylake/vr_config.c b/src/soc/intel/skylake/vr_config.c
new file mode 100644
index 0000000000..40223e32cd
--- /dev/null
+++ b/src/soc/intel/skylake/vr_config.c
@@ -0,0 +1,107 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <soc/vr_config.h>
+
+/* Default values for domain configuration. PSI3 and PSI4 are disabled. */
+static const struct vr_config default_configs[NUM_VR_DOMAINS] = {
+	[VR_SYSTEM_AGENT] = {
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(20),
+		.psi2threshold = VR_CFG_AMP(4),
+		.psi3threshold = VR_CFG_AMP(1),
+		.psi3enable = 0,
+		.psi4enable = 0,
+		.imon_slope = 0x0,
+		.imon_offset = 0x0,
+		.icc_max = VR_CFG_AMP(7),
+		.voltage_limit = 1520,
+	},
+	[VR_IA_CORE] = {
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(20),
+		.psi2threshold = VR_CFG_AMP(5),
+		.psi3threshold = VR_CFG_AMP(1),
+		.psi3enable = 0,
+		.psi4enable = 0,
+		.imon_slope = 0x0,
+		.imon_offset = 0x0,
+		.icc_max = VR_CFG_AMP(34),
+		.voltage_limit = 1520,
+	},
+	[VR_RING] = {
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(20),
+		.psi2threshold = VR_CFG_AMP(5),
+		.psi3threshold = VR_CFG_AMP(1),
+		.psi3enable = 0,
+		.psi4enable = 0,
+		.imon_slope = 0x0,
+		.imon_offset = 0x0,
+		.icc_max = VR_CFG_AMP(34),
+		.voltage_limit = 1520,
+	},
+	[VR_GT_UNSLICED] = {
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(20),
+		.psi2threshold = VR_CFG_AMP(5),
+		.psi3threshold = VR_CFG_AMP(1),
+		.psi3enable = 0,
+		.psi4enable = 0,
+		.imon_slope = 0x0,
+		.imon_offset = 0x0,
+		.icc_max = VR_CFG_AMP(35),
+		.voltage_limit = 1520,
+	},
+	[VR_GT_SLICED] = {
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(20),
+		.psi2threshold = VR_CFG_AMP(5),
+		.psi3threshold = VR_CFG_AMP(1),
+		.psi3enable = 0,
+		.psi4enable = 0,
+		.imon_slope = 0x0,
+		.imon_offset = 0x0,
+		.icc_max = VR_CFG_AMP(35),
+		.voltage_limit = 1520,
+	},
+};
+
+void fill_vr_domain_config(SILICON_INIT_UPD *params, int domain,
+				const struct vr_config *chip_cfg)
+{
+	const struct vr_config *cfg;
+
+	if (domain < 0 || domain >= NUM_VR_DOMAINS)
+		return;
+
+	/* Use device tree override if requested. */
+	if (chip_cfg->vr_config_enable)
+		cfg = chip_cfg;
+	else
+		cfg = &default_configs[domain];
+
+	params->VrConfigEnable[domain] = cfg->vr_config_enable;
+	params->Psi1Threshold[domain] = cfg->psi1threshold;
+	params->Psi2Threshold[domain] = cfg->psi2threshold;
+	params->Psi3Threshold[domain] = cfg->psi3threshold;
+	params->Psi3Enable[domain] = cfg->psi3enable;
+	params->Psi4Enable[domain] = cfg->psi4enable;
+	params->ImonSlope[domain] = cfg->imon_slope;
+	params->ImonOffset[domain] = cfg->imon_offset;
+	params->IccMax[domain] = cfg->icc_max;
+	params->VrVoltageLimit[domain] = cfg->voltage_limit;
+}