soc/intel/common/block: Enable PCH Thermal Sensor for threshold configuration

PMC logic shuts down the PCH thermal sensor when CPU is in a C-state and
DTS Temp <= Low Temp Threshold (LTT) in case of Dynamic Thermal shutdown
when S0ix is enabled.

BUG=None
BRANCH=None
TEST=Verified Thermal Device (B0: D18: F0) TSPM offset 0x1c [LTT (8:0)]
value is 0xFE.

Change-Id: Ibd1e669fcbfe8dc6e6e5556aa5b1373ed19c3685
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33129
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/common/block/include/intelblocks/chip.h

@@ -33,6 +33,8 @@ struct soc_intel_common_config {
 	int chipset_lockdown;
 	struct gspi_cfg gspi[CONFIG_SOC_INTEL_COMMON_BLOCK_GSPI_MAX];
 	struct dw_i2c_bus_config i2c[CONFIG_SOC_INTEL_I2C_DEV_MAX];
+	/* PCH Thermal Trip Temperature in deg C */
+	uint8_t pch_thermal_trip;
 };
 
 /* This function to retrieve soc config structure required by common code */

src/soc/intel/common/block/include/intelblocks/thermal.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Intel Corp.
+ *
+ * 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.
+ */
+
+#ifndef _SOC_INTEL_COMMON_BLOCK_THERMAL_H_
+#define _SOC_INTEL_COMMON_BLOCK_THERMAL_H_
+
+/* Enable thermal sensor power management */
+void pch_thermal_configuration(void);
+
+#endif

src/soc/intel/common/block/thermal/Kconfig

@@ -0,0 +1,5 @@
+config SOC_INTEL_COMMON_BLOCK_THERMAL
+	bool
+	default n
+	help
+	  This option allows to configure PCH thermal registers for supported PCH.

src/soc/intel/common/block/thermal/Makefile.inc

@@ -0,0 +1 @@
+ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_THERMAL) += thermal.c

src/soc/intel/common/block/thermal/thermal.c

@@ -0,0 +1,89 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Intel Corp.
+ *
+ * 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 <console/console.h>
+#include <device/mmio.h>
+#include <intelblocks/chip.h>
+#include <intelblocks/thermal.h>
+#include <soc/pci_devs.h>
+
+#define THERMAL_SENSOR_POWER_MANAGEMENT 0x1c
+#define CATASTROPHIC_TRIP_POINT_MASK 0x1ff
+#define MAX_TRIP_TEMP 205
+/* This is the safest default Trip Temp value */
+#define DEFAULT_TRIP_TEMP 50
+#define GET_LTT_VALUE(x) (((x) + 50) * (2))
+
+static uint8_t get_thermal_trip_temp(void)
+{
+	const struct soc_intel_common_config *common_config;
+	common_config = chip_get_common_soc_structure();
+
+	return common_config->pch_thermal_trip;
+}
+
+/* PCH Low Temp Threshold (LTT) */
+static uint16_t pch_get_ltt_value(struct device *dev)
+{
+	uint16_t ltt_value;
+	uint8_t thermal_config;
+
+	thermal_config = get_thermal_trip_temp();
+	if (!thermal_config)
+		thermal_config = DEFAULT_TRIP_TEMP;
+
+	if (thermal_config > MAX_TRIP_TEMP)
+		die("Input PCH temp trip is higher than allowed range!");
+
+	/* Trip Point Temp = (LTT / 2 - 50 degree C) */
+	ltt_value = GET_LTT_VALUE(thermal_config);
+
+	return ltt_value;
+}
+
+/* Enable thermal sensor power management */
+void pch_thermal_configuration(void)
+{
+	uint16_t reg16;
+	uintptr_t thermalbar;
+	uintptr_t thermalbar_pm;
+	struct device *dev;
+	struct resource *res;
+
+	dev = pcidev_path_on_root(PCH_DEVFN_THERMAL);
+	if (!dev) {
+		printk(BIOS_ERR, "ERROR: PCH_DEVFN_THERMAL device not found!\n");
+		return;
+	}
+
+	res = find_resource(dev, PCI_BASE_ADDRESS_0);
+	if (!res) {
+		printk(BIOS_ERR, "ERROR: PCH thermal device not found!\n");
+		return;
+	}
+
+	/* Get the base address of the resource */
+	thermalbar = res->base;
+
+	/* Get the required thermal address to write the register value */
+	thermalbar_pm = thermalbar + THERMAL_SENSOR_POWER_MANAGEMENT;
+
+	/* Set Low Temp Threshold (LTT) at TSPM offset 0x1c[8:0] */
+	reg16 = read16((uint16_t *)thermalbar_pm);
+	reg16 &= ~CATASTROPHIC_TRIP_POINT_MASK;
+	/* Low Temp Threshold (LTT) */
+	reg16 |= pch_get_ltt_value(dev);
+	write16((uint16_t *)thermalbar_pm, reg16);
+}