thermal: Intel SoC DTS thermal

In the Intel SoCs like Bay Trail, there are 2 additional digital temperature
sensors(DTS), in addition to the standard DTSs in the core. Also they support
4 programmable thresholds, out of which two can be used by OSPM. These
thresholds can be used by OSPM thermal control. Out of these two thresholds,
one is used by driver and one user mode can change via thermal sysfs to get
notifications on threshold violations.

The driver defines one critical trip points, which is set to TJ MAX - offset.
The offset can be changed via module parameter (default 5C). Also it uses
one of the thresholds to get notification for this temperature violation.
This is very important for orderly shutdown as the many of these devices don't
have ACPI thermal zone, and expects that there is some other thermal control
mechanism present in OSPM. When a Linux distro is used without additional
specialized thermal control program, BIOS can do force shutdown when thermals
are not under control. When temperature reaches critical, the Linux thermal
core will initiate an orderly shutdown.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/Kconfig

@@ -222,6 +222,18 @@ config ACPI_INT3403_THERMAL
 	  the Intel Thermal Daemon can use this information to allow the user
 	  to select his laptop to run without turning on the fans.
 
+config INTEL_SOC_DTS_THERMAL
+	tristate "Intel SoCs DTS thermal driver"
+	depends on X86 && IOSF_MBI
+	help
+	  Enable this to register Intel SoCs (e.g. Bay Trail) platform digital
+	  temperature sensor (DTS). These SoCs have two additional DTSs in
+	  addition to DTSs on CPU cores. Each DTS will be registered as a
+	  thermal zone. There are two trip points. One of the trip point can
+	  be set by user mode programs to get notifications via Linux thermal
+	  notification methods.The other trip is a critical trip point, which
+	  was set by the driver based on the TJ MAX temperature.
+
 menu "Texas Instruments thermal drivers"
 source "drivers/thermal/ti-soc-thermal/Kconfig"
 endmenu

drivers/thermal/Makefile

@@ -29,5 +29,6 @@ obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
 obj-$(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-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_ACPI_INT3403_THERMAL)	+= int3403_thermal.o

drivers/thermal/intel_soc_dts_thermal.c

@@ -0,0 +1,479 @@
+/*
+ * intel_soc_dts_thermal.c
+ * Copyright (c) 2014, 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 <linux/thermal.h>
+#include <asm/cpu_device_id.h>
+#include <asm/iosf_mbi.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
+
+/* IRQ 86 is a fixed APIC interrupt for BYT DTS Aux threshold notifications */
+#define BYT_SOC_DTS_APIC_IRQ	86
+
+/* 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
+
+#define CRITICAL_OFFSET_FROM_TJ_MAX	5000
+
+struct soc_sensor_entry {
+	int id;
+	u32 tj_max;
+	u32 temp_mask;
+	u32 temp_shift;
+	u32 store_status;
+	struct thermal_zone_device *tzone;
+};
+
+static struct soc_sensor_entry *soc_dts[SOC_MAX_DTS_SENSORS];
+
+static int crit_offset = CRITICAL_OFFSET_FROM_TJ_MAX;
+module_param(crit_offset, int, 0644);
+MODULE_PARM_DESC(crit_offset,
+	"Critical Temperature offset from tj max in millidegree Celsius.");
+
+static DEFINE_MUTEX(aux_update_mutex);
+static spinlock_t intr_notify_lock;
+static int soc_dts_thres_irq;
+
+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 soc_sensor_entry *aux_entry;
+
+	aux_entry = tzd->devdata;
+
+	if (!trip) {
+		/* Just return the critical temp */
+		*temp = aux_entry->tj_max - crit_offset;
+		return 0;
+	}
+
+	mutex_lock(&aux_update_mutex);
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+					SOC_DTS_OFFSET_PTPS, &out);
+	mutex_unlock(&aux_update_mutex);
+	if (status)
+		return status;
+
+	out = (out >> (trip * 8)) & SOC_DTS_TJMAX_ENCODING;
+
+	if (!out)
+		*temp = 0;
+	else
+		*temp = aux_entry->tj_max - out * 1000;
+
+	return 0;
+}
+
+static int update_trip_temp(struct soc_sensor_entry *aux_entry,
+				int thres_index, unsigned long temp)
+{
+	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 |
+						SOC_DTS_TE_MSI_ENABLE;
+
+	temp_out = (aux_entry->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;
+
+	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 soc_sensor_entry *aux_entry = tzd->devdata;
+	int status;
+
+	if (temp > (aux_entry->tj_max - crit_offset))
+		return -EINVAL;
+
+	mutex_lock(&aux_update_mutex);
+	status = update_trip_temp(tzd->devdata, trip, temp);
+	mutex_unlock(&aux_update_mutex);
+
+	return status;
+}
+
+static int sys_get_trip_type(struct thermal_zone_device *thermal,
+		int trip, enum thermal_trip_type *type)
+{
+	if (trip)
+		*type = THERMAL_TRIP_PASSIVE;
+	else
+		*type = THERMAL_TRIP_CRITICAL;
+
+	return 0;
+}
+
+static int sys_get_curr_temp(struct thermal_zone_device *tzd,
+						unsigned long *temp)
+{
+	int status;
+	u32 out;
+	struct soc_sensor_entry *aux_entry;
+
+	aux_entry = tzd->devdata;
+
+	status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+					SOC_DTS_OFFSET_TEMP, &out);
+	if (status)
+		return status;
+
+	out = (out & aux_entry->temp_mask) >> aux_entry->temp_shift;
+	out -= SOC_DTS_TJMAX_ENCODING;
+	*temp = aux_entry->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 void free_soc_dts(struct soc_sensor_entry *aux_entry)
+{
+	if (aux_entry) {
+		iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+			SOC_DTS_OFFSET_ENABLE, aux_entry->store_status);
+		thermal_zone_device_unregister(aux_entry->tzone);
+		kfree(aux_entry);
+	}
+}
+
+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 struct soc_sensor_entry *alloc_soc_dts(int id, u32 tj_max)
+{
+	struct soc_sensor_entry *aux_entry;
+	char name[10];
+	int err;
+
+	aux_entry = kzalloc(sizeof(*aux_entry), GFP_KERNEL);
+	if (!aux_entry) {
+		err = -ENOMEM;
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* Store status to restor on exit */
+	err = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+					SOC_DTS_OFFSET_ENABLE,
+					&aux_entry->store_status);
+	if (err)
+		goto err_ret;
+
+	aux_entry->id = id;
+	aux_entry->tj_max = tj_max;
+	aux_entry->temp_mask = 0x00FF << (id * 8);
+	aux_entry->temp_shift = id * 8;
+	snprintf(name, sizeof(name), "soc_dts%d", id);
+	aux_entry->tzone = thermal_zone_device_register(name,
+			SOC_MAX_DTS_TRIPS,
+			0x02,
+			aux_entry, &tzone_ops, NULL, 0, 0);
+	if (IS_ERR(aux_entry->tzone)) {
+		err = PTR_ERR(aux_entry->tzone);
+		goto err_ret;
+	}
+
+	err = soc_dts_enable(id);
+	if (err)
+		goto err_aux_status;
+
+	return aux_entry;
+
+err_aux_status:
+	thermal_zone_device_unregister(aux_entry->tzone);
+err_ret:
+	kfree(aux_entry);
+	return ERR_PTR(err);
+}
+
+static void proc_thermal_interrupt(void)
+{
+	u32 sticky_out;
+	int status;
+	u32 ptmc_out;
+
+	/* Clear APIC interrupt */
+	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);
+
+	/* Read status here */
+	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);
+		for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+			pr_debug("TZD update for zone %d\n", i);
+			thermal_zone_device_update(soc_dts[i]->tzone);
+		}
+	}
+
+}
+
+static irqreturn_t soc_irq_thread_fn(int irq, void *dev_data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&intr_notify_lock, flags);
+	proc_thermal_interrupt();
+	spin_unlock_irqrestore(&intr_notify_lock, flags);
+	pr_debug("proc_thermal_interrupt\n");
+
+	return IRQ_HANDLED;
+}
+
+static const struct x86_cpu_id soc_thermal_ids[] = {
+	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, 0x37, 0, BYT_SOC_DTS_APIC_IRQ},
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, soc_thermal_ids);
+
+static int __init intel_soc_thermal_init(void)
+{
+	u32 tj_max;
+	int err = 0;
+	int i;
+	const struct x86_cpu_id *match_cpu;
+
+	match_cpu = x86_match_cpu(soc_thermal_ids);
+	if (!match_cpu)
+		return -ENODEV;
+
+	if (get_tj_max(&tj_max))
+		return -EINVAL;
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		soc_dts[i] = alloc_soc_dts(i, tj_max);
+		if (IS_ERR(soc_dts[i])) {
+			err = PTR_ERR(soc_dts[i]);
+			goto err_free;
+		}
+	}
+
+	spin_lock_init(&intr_notify_lock);
+
+	soc_dts_thres_irq = (int)match_cpu->driver_data;
+
+	err = request_threaded_irq(soc_dts_thres_irq, NULL,
+					soc_irq_thread_fn,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"soc_dts", soc_dts);
+	if (err) {
+		pr_err("request_threaded_irq ret %d\n", err);
+		goto err_free;
+	}
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
+		err = update_trip_temp(soc_dts[i], 0, tj_max - crit_offset);
+		if (err)
+			goto err_trip_temp;
+	}
+
+	return 0;
+
+err_trip_temp:
+	i = SOC_MAX_DTS_SENSORS;
+	free_irq(soc_dts_thres_irq, soc_dts);
+err_free:
+	while (--i >= 0)
+		free_soc_dts(soc_dts[i]);
+
+	return err;
+}
+
+static void __exit intel_soc_thermal_exit(void)
+{
+	int i;
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i)
+		update_trip_temp(soc_dts[i], 0, 0);
+
+	free_irq(soc_dts_thres_irq, soc_dts);
+
+	for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i)
+		free_soc_dts(soc_dts[i]);
+
+}
+
+module_init(intel_soc_thermal_init)
+module_exit(intel_soc_thermal_exit)
+
+MODULE_DESCRIPTION("Intel SoC DTS Thermal Driver");
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL v2");