Thermal: Intel SoC: DTS thermal IOSF core

This is becoming a common feature for Intel SoCs to expose the additional
digital temperature sensors (DTSs) using side band interface (IOSF). This
change remove common IOSF DTS handler function from the existing driver
intel_soc_dts_thermal.c and creates a stand alone module, which can
be selected from the SoC specific drivers. In this way there is less
code duplication.

Signed-off-by: Srinivas Pandruvada <[e-mail]>

drivers/thermal/Kconfig

···
 	  two trip points which can be set by user to get notifications via thermal
 	  notification methods.
 
+config INTEL_SOC_DTS_IOSF_CORE
+	tristate
+	depends on X86
+	select IOSF_MBI
+	help
+	  This is becoming a common feature for Intel SoCs to expose the additional
+	  digital temperature sensors (DTSs) using side band interface (IOSF). This
+	  implements the common set of helper functions to register, get temperature
+	  and get/set thresholds on DTSs.
+
 config INTEL_SOC_DTS_THERMAL
 	tristate "Intel SoCs DTS thermal driver"
 	depends on X86 && IOSF_MBI

drivers/thermal/Makefile

···
 obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
 obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
+obj-$(CONFIG_INTEL_SOC_DTS_IOSF_CORE)	+= intel_soc_dts_iosf.o
 obj-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/

drivers/thermal/intel_soc_dts_iosf.c

···
+/*
+ * intel_soc_dts_iosf.c
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <asm/iosf_mbi.h>
+#include "intel_soc_dts_iosf.h"
+
+#define SOC_DTS_OFFSET_ENABLE		0xB0
+#define SOC_DTS_OFFSET_TEMP		0xB1
+
+#define SOC_DTS_OFFSET_PTPS		0xB2
+#define SOC_DTS_OFFSET_PTTS		0xB3
+#define SOC_DTS_OFFSET_PTTSS		0xB4
+#define SOC_DTS_OFFSET_PTMC		0x80
+#define SOC_DTS_TE_AUX0			0xB5
+#define SOC_DTS_TE_AUX1			0xB6
+
+#define SOC_DTS_AUX0_ENABLE_BIT		BIT(0)
+#define SOC_DTS_AUX1_ENABLE_BIT		BIT(1)
+#define SOC_DTS_CPU_MODULE0_ENABLE_BIT	BIT(16)
+#define SOC_DTS_CPU_MODULE1_ENABLE_BIT	BIT(17)
+#define SOC_DTS_TE_SCI_ENABLE		BIT(9)
+#define SOC_DTS_TE_SMI_ENABLE		BIT(10)
+#define SOC_DTS_TE_MSI_ENABLE		BIT(11)
+#define SOC_DTS_TE_APICA_ENABLE		BIT(14)
+#define SOC_DTS_PTMC_APIC_DEASSERT_BIT	BIT(4)
+
+/* DTS encoding for TJ MAX temperature */
+#define SOC_DTS_TJMAX_ENCODING		0x7F
+
+/* Only 2 out of 4 is allowed for OSPM */
+#define SOC_MAX_DTS_TRIPS		2
+
+/* Mask for two trips in status bits */
+#define SOC_DTS_TRIP_MASK		0x03
+
+/* DTS0 and DTS 1 */
+#define SOC_MAX_DTS_SENSORS		2
+
+static int get_tj_max(u32 *tj_max)
+{
+	u32 eax, edx;
+	u32 val;
+	int err;
+
+	err = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+	if (err)
+		goto err_ret;
+	else {
+		val = (eax >> 16) & 0xff;
+		if (val)
+			*tj_max = val * 1000;
+		else {
+			err = -EINVAL;
+			goto err_ret;
+		}
+	}
+
+	return 0;
+err_ret:
+	*tj_max = 0;
+
+	return err;
+}
+
+static int sys_get_trip_temp(struct thermal_zone_device *tzd, int trip,
+			     unsigned long *temp)
+{
+	int status;
+	u32 out;
+	struct intel_soc_dts_sensor_entry *dts;
+	struct intel_soc_dts_sensors *sensors;
+
+	dts = tzd->devdata;
+	sensors = dts->sensors;
+	mutex_lock(&sensors->dts_update_lock);
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_PTPS, &out);
+	mutex_unlock(&sensors->dts_update_lock);
+	if (status)
+		return status;
+
+	out = (out >> (trip * 8)) & SOC_DTS_TJMAX_ENCODING;
+	if (!out)
+		*temp = 0;
+	else
+		*temp = sensors->tj_max - out * 1000;
+
+	return 0;
+}
+
+static int update_trip_temp(struct intel_soc_dts_sensor_entry *dts,
+			    int thres_index, unsigned long temp,
+			    enum thermal_trip_type trip_type)
+{
+	int status;
+	u32 temp_out;
+	u32 out;
+	u32 store_ptps;
+	u32 store_ptmc;
+	u32 store_te_out;
+	u32 te_out;
+	u32 int_enable_bit = SOC_DTS_TE_APICA_ENABLE;
+	struct intel_soc_dts_sensors *sensors = dts->sensors;
+
+	if (sensors->intr_type == INTEL_SOC_DTS_INTERRUPT_MSI)
+		int_enable_bit |= SOC_DTS_TE_MSI_ENABLE;
+
+	temp_out = (sensors->tj_max - temp) / 1000;
+
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_PTPS, &store_ptps);
+	if (status)
+		return status;
+
+	out = (store_ptps & ~(0xFF << (thres_index * 8)));
+	out |= (temp_out & 0xFF) << (thres_index * 8);
+	status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				SOC_DTS_OFFSET_PTPS, out);
+	if (status)
+		return status;
+
+	pr_debug("update_trip_temp PTPS = %x\n", out);
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_PTMC, &out);
+	if (status)
+		goto err_restore_ptps;
+
+	store_ptmc = out;
+
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_TE_AUX0 + thres_index,
+			       &te_out);
+	if (status)
+		goto err_restore_ptmc;
+
+	store_te_out = te_out;
+	/* Enable for CPU module 0 and module 1 */
+	out |= (SOC_DTS_CPU_MODULE0_ENABLE_BIT |
+					SOC_DTS_CPU_MODULE1_ENABLE_BIT);
+	if (temp) {
+		if (thres_index)
+			out |= SOC_DTS_AUX1_ENABLE_BIT;
+		else
+			out |= SOC_DTS_AUX0_ENABLE_BIT;
+		te_out |= int_enable_bit;
+	} else {
+		if (thres_index)
+			out &= ~SOC_DTS_AUX1_ENABLE_BIT;
+		else
+			out &= ~SOC_DTS_AUX0_ENABLE_BIT;
+		te_out &= ~int_enable_bit;
+	}
+	status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				SOC_DTS_OFFSET_PTMC, out);
+	if (status)
+		goto err_restore_te_out;
+
+	status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				SOC_DTS_TE_AUX0 + thres_index,
+				te_out);
+	if (status)
+		goto err_restore_te_out;
+
+	dts->trip_types[thres_index] = trip_type;
+
+	return 0;
+err_restore_te_out:
+	iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+		       SOC_DTS_OFFSET_PTMC, store_te_out);
+err_restore_ptmc:
+	iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+		       SOC_DTS_OFFSET_PTMC, store_ptmc);
+err_restore_ptps:
+	iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+		       SOC_DTS_OFFSET_PTPS, store_ptps);
+	/* Nothing we can do if restore fails */
+
+	return status;
+}
+
+static int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip,
+			     unsigned long temp)
+{
+	struct intel_soc_dts_sensor_entry *dts = tzd->devdata;
+	struct intel_soc_dts_sensors *sensors = dts->sensors;
+	int status;
+
+	if (temp > sensors->tj_max)
+		return -EINVAL;
+
+	mutex_lock(&sensors->dts_update_lock);
+	status = update_trip_temp(tzd->devdata, trip, temp,
+				  dts->trip_types[trip]);
+	mutex_unlock(&sensors->dts_update_lock);
+
+	return status;
+}
+
+static int sys_get_trip_type(struct thermal_zone_device *tzd,
+			     int trip, enum thermal_trip_type *type)
+{
+	struct intel_soc_dts_sensor_entry *dts;
+
+	dts = tzd->devdata;
+
+	*type = dts->trip_types[trip];
+
+	return 0;
+}
+
+static int sys_get_curr_temp(struct thermal_zone_device *tzd,
+			     unsigned long *temp)
+{
+	int status;
+	u32 out;
+	struct intel_soc_dts_sensor_entry *dts;
+	struct intel_soc_dts_sensors *sensors;
+
+	dts = tzd->devdata;
+	sensors = dts->sensors;
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_TEMP, &out);
+	if (status)
+		return status;
+
+	out = (out & dts->temp_mask) >> dts->temp_shift;
+	out -= SOC_DTS_TJMAX_ENCODING;
+	*temp = sensors->tj_max - out * 1000;
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops tzone_ops = {
+	.get_temp = sys_get_curr_temp,
+	.get_trip_temp = sys_get_trip_temp,
+	.get_trip_type = sys_get_trip_type,
+	.set_trip_temp = sys_set_trip_temp,
+};
+
+static int soc_dts_enable(int id)
+{
+	u32 out;
+	int ret;
+
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			    SOC_DTS_OFFSET_ENABLE, &out);
+	if (ret)
+		return ret;
+
+	if (!(out & BIT(id))) {
+		out |= BIT(id);
+		ret = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				     SOC_DTS_OFFSET_ENABLE, out);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static void remove_dts_thermal_zone(struct intel_soc_dts_sensor_entry *dts)
+{
+	if (dts) {
+		iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+			       SOC_DTS_OFFSET_ENABLE, dts->store_status);
+		thermal_zone_device_unregister(dts->tzone);
+	}
+}
+
+static int add_dts_thermal_zone(int id, struct intel_soc_dts_sensor_entry *dts,
+				bool notification_support, int trip_cnt,
+				int read_only_trip_cnt)
+{
+	char name[10];
+	int trip_count = 0;
+	int trip_mask = 0;
+	u32 store_ptps;
+	int ret;
+	int i;
+
+	/* Store status to restor on exit */
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			    SOC_DTS_OFFSET_ENABLE,
+			    &dts->store_status);
+	if (ret)
+		goto err_ret;
+
+	dts->id = id;
+	dts->temp_mask = 0x00FF << (id * 8);
+	dts->temp_shift = id * 8;
+	if (notification_support) {
+		trip_count = min(SOC_MAX_DTS_TRIPS, trip_cnt);
+		trip_mask = BIT(trip_count - read_only_trip_cnt) - 1;
+	}
+
+	/* Check if the writable trip we provide is not used by BIOS */
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			    SOC_DTS_OFFSET_PTPS, &store_ptps);
+	if (ret)
+		trip_mask = 0;
+	else {
+		for (i = 0; i < trip_count; ++i) {
+			if (trip_mask & BIT(i))
+				if (store_ptps & (0xff << (i * 8)))
+					trip_mask &= ~BIT(i);
+		}
+	}
+	dts->trip_mask = trip_mask;
+	dts->trip_count = trip_count;
+	snprintf(name, sizeof(name), "soc_dts%d", id);
+	dts->tzone = thermal_zone_device_register(name,
+						  trip_count,
+						  trip_mask,
+						  dts, &tzone_ops,
+						  NULL, 0, 0);
+	if (IS_ERR(dts->tzone)) {
+		ret = PTR_ERR(dts->tzone);
+		goto err_ret;
+	}
+
+	ret = soc_dts_enable(id);
+	if (ret)
+		goto err_enable;
+
+	return 0;
+err_enable:
+	thermal_zone_device_unregister(dts->tzone);
+err_ret:
+	return ret;
+}
+
+int intel_soc_dts_iosf_add_read_only_critical_trip(
+	struct intel_soc_dts_sensors *sensors, int critical_offset)
+{
+	int i, j;
+	int ret;
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		for (j = 0; j < sensors->soc_dts[i].trip_count; ++j) {
+			if (!(sensors->soc_dts[i].trip_mask & BIT(j))) {
+				ret = update_trip_temp(&sensors->soc_dts[i], j,
+					sensors->tj_max - critical_offset,
+					THERMAL_TRIP_CRITICAL);
+				if (ret)
+					return ret;
+
+				return 0;
+			}
+		}
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(intel_soc_dts_iosf_add_read_only_critical_trip);
+
+void intel_soc_dts_iosf_interrupt_handler(struct intel_soc_dts_sensors *sensors)
+{
+	u32 sticky_out;
+	int status;
+	u32 ptmc_out;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sensors->intr_notify_lock, flags);
+
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_PTMC, &ptmc_out);
+	ptmc_out |= SOC_DTS_PTMC_APIC_DEASSERT_BIT;
+	status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				SOC_DTS_OFFSET_PTMC, ptmc_out);
+
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+			       SOC_DTS_OFFSET_PTTSS, &sticky_out);
+	pr_debug("status %d PTTSS %x\n", status, sticky_out);
+	if (sticky_out & SOC_DTS_TRIP_MASK) {
+		int i;
+		/* reset sticky bit */
+		status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+					SOC_DTS_OFFSET_PTTSS, sticky_out);
+		spin_unlock_irqrestore(&sensors->intr_notify_lock, flags);
+
+		for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+			pr_debug("TZD update for zone %d\n", i);
+			thermal_zone_device_update(sensors->soc_dts[i].tzone);
+		}
+	} else
+		spin_unlock_irqrestore(&sensors->intr_notify_lock, flags);
+}
+EXPORT_SYMBOL_GPL(intel_soc_dts_iosf_interrupt_handler);
+
+struct intel_soc_dts_sensors *intel_soc_dts_iosf_init(
+	enum intel_soc_dts_interrupt_type intr_type, int trip_count,
+	int read_only_trip_count)
+{
+	struct intel_soc_dts_sensors *sensors;
+	bool notification;
+	u32 tj_max;
+	int ret;
+	int i;
+
+	if (!iosf_mbi_available())
+		return ERR_PTR(-ENODEV);
+
+	if (!trip_count || read_only_trip_count > trip_count)
+		return ERR_PTR(-EINVAL);
+
+	if (get_tj_max(&tj_max))
+		return ERR_PTR(-EINVAL);
+
+	sensors = kzalloc(sizeof(*sensors), GFP_KERNEL);
+	if (!sensors)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&sensors->intr_notify_lock);
+	mutex_init(&sensors->dts_update_lock);
+	sensors->intr_type = intr_type;
+	sensors->tj_max = tj_max;
+	if (intr_type == INTEL_SOC_DTS_INTERRUPT_NONE)
+		notification = false;
+	else
+		notification = true;
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		sensors->soc_dts[i].sensors = sensors;
+		ret = add_dts_thermal_zone(i, &sensors->soc_dts[i],
+					   notification, trip_count,
+					   read_only_trip_count);
+		if (ret)
+			goto err_free;
+	}
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		ret = update_trip_temp(&sensors->soc_dts[i], 0, 0,
+				       THERMAL_TRIP_PASSIVE);
+		if (ret)
+			goto err_remove_zone;
+
+		ret = update_trip_temp(&sensors->soc_dts[i], 1, 0,
+				       THERMAL_TRIP_PASSIVE);
+		if (ret)
+			goto err_remove_zone;
+	}
+
+	return sensors;
+err_remove_zone:
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i)
+		remove_dts_thermal_zone(&sensors->soc_dts[i]);
+
+err_free:
+	kfree(sensors);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(intel_soc_dts_iosf_init);
+
+void intel_soc_dts_iosf_exit(struct intel_soc_dts_sensors *sensors)
+{
+	int i;
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		update_trip_temp(&sensors->soc_dts[i], 0, 0, 0);
+		update_trip_temp(&sensors->soc_dts[i], 1, 0, 0);
+		remove_dts_thermal_zone(&sensors->soc_dts[i]);
+	}
+	kfree(sensors);
+}
+EXPORT_SYMBOL_GPL(intel_soc_dts_iosf_exit);
+
+MODULE_LICENSE("GPL v2");

drivers/thermal/intel_soc_dts_iosf.h

···
+/*
+ * intel_soc_dts_iosf.h
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 _INTEL_SOC_DTS_IOSF_CORE_H
+#define _INTEL_SOC_DTS_IOSF_CORE_H
+
+#include <linux/thermal.h>
+
+/* DTS0 and DTS 1 */
+#define SOC_MAX_DTS_SENSORS	2
+
+enum intel_soc_dts_interrupt_type {
+	INTEL_SOC_DTS_INTERRUPT_NONE,
+	INTEL_SOC_DTS_INTERRUPT_APIC,
+	INTEL_SOC_DTS_INTERRUPT_MSI,
+	INTEL_SOC_DTS_INTERRUPT_SCI,
+	INTEL_SOC_DTS_INTERRUPT_SMI,
+};
+
+struct intel_soc_dts_sensors;
+
+struct intel_soc_dts_sensor_entry {
+	int id;
+	u32 temp_mask;
+	u32 temp_shift;
+	u32 store_status;
+	u32 trip_mask;
+	u32 trip_count;
+	enum thermal_trip_type trip_types[2];
+	struct thermal_zone_device *tzone;
+	struct intel_soc_dts_sensors *sensors;
+};
+
+struct intel_soc_dts_sensors {
+	u32 tj_max;
+	spinlock_t intr_notify_lock;
+	struct mutex dts_update_lock;
+	enum intel_soc_dts_interrupt_type intr_type;
+	struct intel_soc_dts_sensor_entry soc_dts[SOC_MAX_DTS_SENSORS];
+};
+
+struct intel_soc_dts_sensors *intel_soc_dts_iosf_init(
+	enum intel_soc_dts_interrupt_type intr_type, int trip_count,
+	int read_only_trip_count);
+void intel_soc_dts_iosf_exit(struct intel_soc_dts_sensors *sensors);
+void intel_soc_dts_iosf_interrupt_handler(
+				struct intel_soc_dts_sensors *sensors);
+int intel_soc_dts_iosf_add_read_only_critical_trip(
+	struct intel_soc_dts_sensors *sensors, int critical_offset);
+#endif