hwmon: Add PECI cputemp driver

This commit adds PECI cputemp hwmon driver.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Reviewed-by: James Feist <james.feist@linux.intel.com>
Reviewed-by: Vernon Mauery <vernon.mauery@linux.intel.com>

4 files changed, 533 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index c4578e8f34bb..3e029f4fba6a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1517,6 +1517,20 @@ config SENSORS_PCF8591
 	  These devices are hard to detect and rarely found on mainstream
 	  hardware. If unsure, say N.
 
+config SENSORS_PECI_CPUTEMP
+	tristate "PECI CPU temperature monitoring client"
+	depends on PECI
+	select MFD_INTEL_PECI_CLIENT
+	help
+	  If you say yes here you get support for the generic Intel PECI
+	  cputemp driver which provides Digital Thermal Sensor (DTS) thermal
+	  readings of the CPU package and CPU cores that are accessible using
+	  the PECI Client Command Suite via the processor PECI client.
+	  Check <file:Documentation/hwmon/peci-cputemp.rst> for details.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called peci-cputemp.
+
 source "drivers/hwmon/pmbus/Kconfig"
 
 config SENSORS_PWM_FAN
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 162940270661..b63ff53de1b4 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -159,6 +159,7 @@ obj-$(CONFIG_SENSORS_NZXT_KRAKEN2) += nzxt-kraken2.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
+obj-$(CONFIG_SENSORS_PECI_CPUTEMP)	+= peci-cputemp.o
 obj-$(CONFIG_SENSORS_POWR1220)  += powr1220.o
 obj-$(CONFIG_SENSORS_PWM_FAN)	+= pwm-fan.o
 obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON)	+= raspberrypi-hwmon.o
diff --git a/drivers/hwmon/peci-cputemp.c b/drivers/hwmon/peci-cputemp.c
new file mode 100644
index 000000000000..7b68cf6b20af
--- /dev/null
+++ b/drivers/hwmon/peci-cputemp.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018-2019 Intel Corporation
+
+#include <linux/hwmon.h>
+#include <linux/jiffies.h>
+#include <linux/mfd/intel-peci-client.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include "peci-hwmon.h"
+
+#define DEFAULT_CHANNEL_NUMS	5
+#define MODTEMP_CHANNEL_NUMS	CORE_MASK_BITS_MAX
+#define CPUTEMP_CHANNEL_NUMS	(DEFAULT_CHANNEL_NUMS + MODTEMP_CHANNEL_NUMS)
+
+struct temp_group {
+	struct peci_sensor_data		die;
+	struct peci_sensor_data		dts;
+	struct peci_sensor_data		tcontrol;
+	struct peci_sensor_data		tthrottle;
+	struct peci_sensor_data		tjmax;
+	struct peci_sensor_data		module[MODTEMP_CHANNEL_NUMS];
+};
+
+struct peci_cputemp {
+	struct peci_client_manager	*mgr;
+	struct device			*dev;
+	char				name[PECI_NAME_SIZE];
+	const struct cpu_gen_info	*gen_info;
+	struct temp_group		temp;
+	u64				core_mask;
+	u32				temp_config[CPUTEMP_CHANNEL_NUMS + 1];
+	uint				config_idx;
+	struct hwmon_channel_info	temp_info;
+	const struct hwmon_channel_info	*info[2];
+	struct hwmon_chip_info		chip;
+	char				**module_temp_label;
+};
+
+enum cputemp_channels {
+	channel_die,
+	channel_dts,
+	channel_tcontrol,
+	channel_tthrottle,
+	channel_tjmax,
+	channel_core,
+};
+
+static const u32 config_table[] = {
+	/* Die temperature */
+	HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+	HWMON_T_CRIT_HYST,
+
+	/* DTS margin */
+	HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+	HWMON_T_CRIT_HYST,
+
+	/* Tcontrol temperature */
+	HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_CRIT,
+
+	/* Tthrottle temperature */
+	HWMON_T_LABEL | HWMON_T_INPUT,
+
+	/* Tjmax temperature */
+	HWMON_T_LABEL | HWMON_T_INPUT,
+
+	/* Core temperature - for all core channels */
+	HWMON_T_LABEL | HWMON_T_INPUT,
+};
+
+static const char *cputemp_label[DEFAULT_CHANNEL_NUMS] = {
+	"Die",
+	"DTS",
+	"Tcontrol",
+	"Tthrottle",
+	"Tjmax"
+};
+
+static s32 ten_dot_six_to_millidegree(s32 val)
+{
+	return ((val ^ 0x8000) - 0x8000) * 1000 / 64;
+}
+
+static int get_temp_targets(struct peci_cputemp *priv)
+{
+	s32 tthrottle_offset;
+	s32 tcontrol_margin;
+	u8  pkg_cfg[4];
+	int ret;
+
+	/*
+	 * Just use only the tcontrol marker to determine if target values need
+	 * update.
+	 */
+	if (!peci_sensor_need_update(&priv->temp.tcontrol))
+		return 0;
+
+	ret = peci_client_read_package_config(priv->mgr,
+					      PECI_MBX_INDEX_TEMP_TARGET, 0,
+					      pkg_cfg);
+	if (ret)
+		return ret;
+
+	priv->temp.tjmax.value = pkg_cfg[2] * 1000;
+
+	tcontrol_margin = pkg_cfg[1];
+	tcontrol_margin = ((tcontrol_margin ^ 0x80) - 0x80) * 1000;
+	priv->temp.tcontrol.value = priv->temp.tjmax.value - tcontrol_margin;
+
+	tthrottle_offset = (pkg_cfg[3] & 0x2f) * 1000;
+	priv->temp.tthrottle.value = priv->temp.tjmax.value - tthrottle_offset;
+
+	peci_sensor_mark_updated(&priv->temp.tcontrol);
+
+	return 0;
+}
+
+static int get_die_temp(struct peci_cputemp *priv)
+{
+	struct peci_get_temp_msg msg;
+	int ret;
+
+	if (!peci_sensor_need_update(&priv->temp.die))
+		return 0;
+
+	msg.addr = priv->mgr->client->addr;
+
+	ret = peci_command(priv->mgr->client->adapter, PECI_CMD_GET_TEMP, &msg);
+	if (ret)
+		return ret;
+
+	/* Note that the tjmax should be available before calling it */
+	priv->temp.die.value = priv->temp.tjmax.value +
+			       (msg.temp_raw * 1000 / 64);
+
+	peci_sensor_mark_updated(&priv->temp.die);
+
+	return 0;
+}
+
+static int get_dts(struct peci_cputemp *priv)
+{
+	s32 dts_margin;
+	u8  pkg_cfg[4];
+	int ret;
+
+	if (!peci_sensor_need_update(&priv->temp.dts))
+		return 0;
+
+	ret = peci_client_read_package_config(priv->mgr,
+					      PECI_MBX_INDEX_DTS_MARGIN, 0,
+					      pkg_cfg);
+
+	if (ret)
+		return ret;
+
+	dts_margin = le16_to_cpup((__le16 *)pkg_cfg);
+
+	/**
+	 * Processors return a value of DTS reading in 10.6 format
+	 * (10 bits signed decimal, 6 bits fractional).
+	 * Error codes:
+	 *   0x8000: General sensor error
+	 *   0x8001: Reserved
+	 *   0x8002: Underflow on reading value
+	 *   0x8003-0x81ff: Reserved
+	 */
+	if (dts_margin >= 0x8000 && dts_margin <= 0x81ff)
+		return -EIO;
+
+	dts_margin = ten_dot_six_to_millidegree(dts_margin);
+
+	/* Note that the tcontrol should be available before calling it */
+	priv->temp.dts.value = priv->temp.tcontrol.value - dts_margin;
+
+	peci_sensor_mark_updated(&priv->temp.dts);
+
+	return 0;
+}
+
+static int get_module_temp(struct peci_cputemp *priv, int index)
+{
+	s32 module_dts_margin;
+	u8  pkg_cfg[4];
+	int ret;
+
+	if (!peci_sensor_need_update(&priv->temp.module[index]))
+		return 0;
+
+	ret = peci_client_read_package_config(priv->mgr,
+					      PECI_MBX_INDEX_MODULE_TEMP,
+					      index, pkg_cfg);
+	if (ret)
+		return ret;
+
+	module_dts_margin = le16_to_cpup((__le16 *)pkg_cfg);
+
+	/*
+	 * Processors return a value of the DTS reading in 10.6 format
+	 * (10 bits signed decimal, 6 bits fractional).
+	 * Error codes:
+	 *   0x8000: General sensor error
+	 *   0x8001: Reserved
+	 *   0x8002: Underflow on reading value
+	 *   0x8003-0x81ff: Reserved
+	 */
+	if (module_dts_margin >= 0x8000 && module_dts_margin <= 0x81ff)
+		return -EIO;
+
+	module_dts_margin = ten_dot_six_to_millidegree(module_dts_margin);
+
+	/* Note that the tjmax should be available before calling it */
+	priv->temp.module[index].value = priv->temp.tjmax.value +
+					 module_dts_margin;
+
+	peci_sensor_mark_updated(&priv->temp.module[index]);
+
+	return 0;
+}
+
+static int cputemp_read_string(struct device *dev,
+			       enum hwmon_sensor_types type,
+			       u32 attr, int channel, const char **str)
+{
+	struct peci_cputemp *priv = dev_get_drvdata(dev);
+
+	if (attr != hwmon_temp_label)
+		return -EOPNOTSUPP;
+
+	*str = (channel < DEFAULT_CHANNEL_NUMS) ?
+	       cputemp_label[channel] :
+	       (const char *)priv->module_temp_label[channel -
+						     DEFAULT_CHANNEL_NUMS];
+
+	return 0;
+}
+
+static int cputemp_read(struct device *dev,
+			enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct peci_cputemp *priv = dev_get_drvdata(dev);
+	int ret, module_index;
+
+	if (channel >= CPUTEMP_CHANNEL_NUMS ||
+	    !(priv->temp_config[channel] & BIT(attr)))
+		return -EOPNOTSUPP;
+
+	ret = get_temp_targets(priv);
+	if (ret)
+		return ret;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		switch (channel) {
+		case channel_die:
+			ret = get_die_temp(priv);
+			if (ret)
+				break;
+
+			*val = priv->temp.die.value;
+			break;
+		case channel_dts:
+			ret = get_dts(priv);
+			if (ret)
+				break;
+
+			*val = priv->temp.dts.value;
+			break;
+		case channel_tcontrol:
+			*val = priv->temp.tcontrol.value;
+			break;
+		case channel_tthrottle:
+			*val = priv->temp.tthrottle.value;
+			break;
+		case channel_tjmax:
+			*val = priv->temp.tjmax.value;
+			break;
+		default:
+			module_index = channel - DEFAULT_CHANNEL_NUMS;
+			ret = get_module_temp(priv, module_index);
+			if (ret)
+				break;
+
+			*val = priv->temp.module[module_index].value;
+			break;
+		}
+		break;
+	case hwmon_temp_max:
+		*val = priv->temp.tcontrol.value;
+		break;
+	case hwmon_temp_crit:
+		*val = priv->temp.tjmax.value;
+		break;
+	case hwmon_temp_crit_hyst:
+		*val = priv->temp.tjmax.value - priv->temp.tcontrol.value;
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
+static umode_t cputemp_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	const struct peci_cputemp *priv = data;
+
+	if (channel < ARRAY_SIZE(priv->temp_config) &&
+	    (priv->temp_config[channel] & BIT(attr)) &&
+	    (channel < DEFAULT_CHANNEL_NUMS ||
+	     (channel >= DEFAULT_CHANNEL_NUMS &&
+	      (priv->core_mask & BIT(channel - DEFAULT_CHANNEL_NUMS)))))
+		return 0444;
+
+	return 0;
+}
+
+static const struct hwmon_ops cputemp_ops = {
+	.is_visible = cputemp_is_visible,
+	.read_string = cputemp_read_string,
+	.read = cputemp_read,
+};
+
+static int check_resolved_cores(struct peci_cputemp *priv)
+{
+	struct peci_rd_pci_cfg_local_msg msg;
+	int ret;
+
+	/* Get the RESOLVED_CORES register value */
+	msg.addr = priv->mgr->client->addr;
+	msg.device = 30;
+	msg.function = 3;
+	msg.rx_len = 4;
+	msg.bus = 1;
+	msg.reg = 0xb4;
+
+	ret = peci_command(priv->mgr->client->adapter,
+			   PECI_CMD_RD_PCI_CFG_LOCAL, &msg);
+	if (msg.cc != PECI_DEV_CC_SUCCESS)
+		ret = -EAGAIN;
+	if (ret)
+		return ret;
+
+	priv->core_mask = le32_to_cpup((__le32 *)msg.pci_config);
+	if (!priv->core_mask)
+		return -EAGAIN;
+
+	dev_dbg(priv->dev, "Scanned resolved cores: 0x%llx\n", priv->core_mask);
+
+	return 0;
+}
+
+static int create_module_temp_label(struct peci_cputemp *priv, int idx)
+{
+	priv->module_temp_label[idx] = devm_kzalloc(priv->dev,
+						    PECI_HWMON_LABEL_STR_LEN,
+						    GFP_KERNEL);
+	if (!priv->module_temp_label[idx])
+		return -ENOMEM;
+
+	sprintf(priv->module_temp_label[idx], "Core %d", idx);
+
+	return 0;
+}
+
+static int create_module_temp_info(struct peci_cputemp *priv)
+{
+	int ret, i;
+
+	ret = check_resolved_cores(priv);
+	if (ret)
+		return ret;
+
+	priv->module_temp_label = devm_kzalloc(priv->dev,
+					       MODTEMP_CHANNEL_NUMS *
+					       sizeof(char *),
+					       GFP_KERNEL);
+	if (!priv->module_temp_label)
+		return -ENOMEM;
+
+	for (i = 0; i < MODTEMP_CHANNEL_NUMS; i++) {
+		priv->temp_config[priv->config_idx++] = config_table[channel_core];
+
+		if (i < priv->gen_info->core_mask_bits && priv->core_mask & BIT(i)) {
+			ret = create_module_temp_label(priv, i);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int peci_cputemp_probe(struct platform_device *pdev)
+{
+	struct peci_client_manager *mgr = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct peci_cputemp *priv;
+	struct device *hwmon_dev;
+	int ret;
+
+	if ((mgr->client->adapter->cmd_mask &
+	    (BIT(PECI_CMD_GET_TEMP) | BIT(PECI_CMD_RD_PKG_CFG))) !=
+	    (BIT(PECI_CMD_GET_TEMP) | BIT(PECI_CMD_RD_PKG_CFG)))
+		return -ENODEV;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+	priv->mgr = mgr;
+	priv->dev = dev;
+	priv->gen_info = mgr->gen_info;
+
+	snprintf(priv->name, PECI_NAME_SIZE, "peci_cputemp.cpu%d",
+		 mgr->client->addr - PECI_BASE_ADDR);
+
+	priv->temp_config[priv->config_idx++] = config_table[channel_die];
+	priv->temp_config[priv->config_idx++] = config_table[channel_dts];
+	priv->temp_config[priv->config_idx++] = config_table[channel_tcontrol];
+	priv->temp_config[priv->config_idx++] = config_table[channel_tthrottle];
+	priv->temp_config[priv->config_idx++] = config_table[channel_tjmax];
+
+	ret = create_module_temp_info(priv);
+	if (ret)
+		dev_dbg(dev, "Skipped creating core temp info\n");
+
+	priv->chip.ops = &cputemp_ops;
+	priv->chip.info = priv->info;
+
+	priv->info[0] = &priv->temp_info;
+
+	priv->temp_info.type = hwmon_temp;
+	priv->temp_info.config = priv->temp_config;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(priv->dev,
+							 priv->name,
+							 priv,
+							 &priv->chip,
+							 NULL);
+
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_dbg(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), priv->name);
+
+	return 0;
+}
+
+static const struct platform_device_id peci_cputemp_ids[] = {
+	{ .name = "peci-cputemp", .driver_data = 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, peci_cputemp_ids);
+
+static struct platform_driver peci_cputemp_driver = {
+	.probe		= peci_cputemp_probe,
+	.id_table	= peci_cputemp_ids,
+	.driver		= { .name = KBUILD_MODNAME, },
+};
+module_platform_driver(peci_cputemp_driver);
+
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_DESCRIPTION("PECI cputemp driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/hwmon/peci-hwmon.h b/drivers/hwmon/peci-hwmon.h
new file mode 100644
index 000000000000..4d78c528c4c8
--- /dev/null
+++ b/drivers/hwmon/peci-hwmon.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018-2019 Intel Corporation */
+
+#ifndef __PECI_HWMON_H
+#define __PECI_HWMON_H
+
+#include <linux/peci.h>
+
+#define TEMP_TYPE_PECI			6 /* Sensor type 6: Intel PECI */
+#define UPDATE_INTERVAL			HZ
+
+#define PECI_HWMON_LABEL_STR_LEN	10
+
+/**
+ * struct peci_sensor_data - PECI sensor information
+ * @valid: flag to indicate the sensor value is valid
+ * @value: sensor value in millidegree Celsius
+ * @last_updated: time of the last update in jiffies
+ */
+struct peci_sensor_data {
+	uint  valid;
+	s32   value;
+	ulong last_updated;
+};
+
+/**
+ * peci_sensor_need_update - check whether sensor update is needed or not
+ * @sensor: pointer to sensor data struct
+ *
+ * Return: true if update is needed, false if not.
+ */
+static inline bool peci_sensor_need_update(struct peci_sensor_data *sensor)
+{
+	return !sensor->valid ||
+	       time_after(jiffies, sensor->last_updated + UPDATE_INTERVAL);
+}
+
+/**
+ * peci_sensor_mark_updated - mark the sensor is updated
+ * @sensor: pointer to sensor data struct
+ */
+static inline void peci_sensor_mark_updated(struct peci_sensor_data *sensor)
+{
+	sensor->valid = 1;
+	sensor->last_updated = jiffies;
+}
+
+#endif /* __PECI_HWMON_H */