[v11,13/14] hwmon: Add PECI cputemp driver

This commit adds PECI cputemp hwmon driver.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jason M Biils <jason.m.bills@linux.intel.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
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>
Acked-by: Guenter Roeck <linux@roeck-us.net>
---
Changes since v10:
- Added Skylake Xeon D support.
- Added DTS temperature which is more thermal control friendlier than Die
  temperature.
- Fixed minor bugs and style issues.

 drivers/hwmon/Kconfig        |  14 ++
 drivers/hwmon/Makefile       |   1 +
 drivers/hwmon/peci-cputemp.c | 448 +++++++++++++++++++++++++++++++++++
 drivers/hwmon/peci-hwmon.h   |  46 ++++
 4 files changed, 509 insertions(+)
 create mode 100644 drivers/hwmon/peci-cputemp.c
 create mode 100644 drivers/hwmon/peci-hwmon.h

On 12/11/19 11:46 AM, Jae Hyun Yoo wrote:
> This commit adds PECI cputemp hwmon driver.
> 
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Alan Cox <alan@linux.intel.com>
> Cc: Andrew Jeffery <andrew@aj.id.au>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> Cc: Joel Stanley <joel@jms.id.au>
> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
> 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>
> Acked-by: Guenter Roeck <linux@roeck-us.net>
> ---
> Changes since v10:
> - Added Skylake Xeon D support.
> - Added DTS temperature which is more thermal control friendlier than Die
>    temperature.
> - Fixed minor bugs and style issues.
> 
>   drivers/hwmon/Kconfig        |  14 ++
>   drivers/hwmon/Makefile       |   1 +
>   drivers/hwmon/peci-cputemp.c | 448 +++++++++++++++++++++++++++++++++++
>   drivers/hwmon/peci-hwmon.h   |  46 ++++
>   4 files changed, 509 insertions(+)
>   create mode 100644 drivers/hwmon/peci-cputemp.c
>   create mode 100644 drivers/hwmon/peci-hwmon.h
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 23dfe848979a..b6604759579c 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1349,6 +1349,20 @@ 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 6db5db9cdc29..d6fea48697af 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -144,6 +144,7 @@ obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
>   obj-$(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..70ced9f9299f
> --- /dev/null
> +++ b/drivers/hwmon/peci-cputemp.c
> @@ -0,0 +1,448 @@
> +// 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 CORETEMP_CHANNEL_NUMS  CORE_NUMS_MAX

Why not just use CORE_NUMS_MAX ?

> +#define CPUTEMP_CHANNEL_NUMS   (DEFAULT_CHANNEL_NUMS + CORETEMP_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 core[CORETEMP_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;
> +};
> +
> +enum cputemp_channels {
> +	channel_die,
> +	channel_dts,
> +	channel_tcontrol,
> +	channel_tthrottle,
> +	channel_tjmax,
> +	channel_core,
> +};
> +
> +static const u32 config_table[DEFAULT_CHANNEL_NUMS + 1] = {
> +	/* 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 | HWMON_T_MAX | HWMON_T_CRIT |
> +	HWMON_T_CRIT_HYST,
> +};
> +
> +static const char *cputemp_label[CPUTEMP_CHANNEL_NUMS] = {
> +	"Die",
> +	"DTS",
> +	"Tcontrol",
> +	"Tthrottle",
> +	"Tjmax",
> +	"Core 0", "Core 1", "Core 2", "Core 3",
> +	"Core 4", "Core 5", "Core 6", "Core 7",
> +	"Core 8", "Core 9", "Core 10", "Core 11",
> +	"Core 12", "Core 13", "Core 14", "Core 15",
> +	"Core 16", "Core 17", "Core 18", "Core 19",
> +	"Core 20", "Core 21", "Core 22", "Core 23",
> +	"Core 24", "Core 25", "Core 26", "Core 27",
> +};
> +

What happens if CPUTEMP_CHANNEL_NUMS is increased in the future,
and some of this array includes NULL pointers because this file
doesn't track CORE_NUMS_MAX ?

> +static s32 ten_dot_six_to_millidegree(s32 val)
> +{
> +	return ((val ^ 0x8000) - 0x8000) * 1000 / 64;

Normally I suggest to use DIV_ROUND_CLOSEST in situations like this
to improve rounding, but ultimately that is your call.

> +}
> +
> +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 = (pkg_cfg[1] << 8) | pkg_cfg[0];
> +
> +	/**
> +	 * 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_core_temp(struct peci_cputemp *priv, int core_index)
> +{
> +	s32 core_dts_margin;
> +	u8  pkg_cfg[4];
> +	int ret;
> +
> +	if (!peci_sensor_need_update(&priv->temp.core[core_index]))
> +		return 0;
> +
> +	ret = peci_client_read_package_config(priv->mgr,
> +					      PECI_MBX_INDEX_PER_CORE_DTS_TEMP,
> +					      core_index, pkg_cfg);
> +	if (ret)
> +		return ret;
> +
> +	core_dts_margin = le16_to_cpup((__le16 *)pkg_cfg);
> +

Any special readon for using the helper function here but not
above ?

> +	/*
> +	 * Processors return a value of the core 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 (core_dts_margin >= 0x8000 && core_dts_margin <= 0x81ff)
> +		return -EIO;
> +
> +	core_dts_margin = ten_dot_six_to_millidegree(core_dts_margin);
> +
> +	/* Note that the tjmax should be available before calling it */
> +	priv->temp.core[core_index].value = priv->temp.tjmax.value +
> +					    core_dts_margin;
> +
> +	peci_sensor_mark_updated(&priv->temp.core[core_index]);
> +
> +	return 0;
> +}
> +
> +static int cputemp_read_string(struct device *dev,
> +			       enum hwmon_sensor_types type,
> +			       u32 attr, int channel, const char **str)
> +{
> +	if (attr != hwmon_temp_label)
> +		return -EOPNOTSUPP;
> +
> +	*str = cputemp_label[channel];
> +
> +	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, core_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:
> +			core_index = channel - DEFAULT_CHANNEL_NUMS;
> +			ret = get_core_temp(priv, core_index);
> +			if (ret)
> +				break;
> +
> +			*val = priv->temp.core[core_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_core_temp_info(struct peci_cputemp *priv)
> +{
> +	int ret, i;
> +
> +	ret = check_resolved_cores(priv);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < priv->gen_info->core_max; i++)
> +		if (priv->core_mask & BIT(i))
> +			while (priv->config_idx <= i + DEFAULT_CHANNEL_NUMS)
> +				priv->temp_config[priv->config_idx++] =
> +					config_table[channel_core];
> +
> +	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_core_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..e0e3c901c6e4
> --- /dev/null
> +++ b/drivers/hwmon/peci-hwmon.h
> @@ -0,0 +1,46 @@
> +/* 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
> +
> +/**
> + * 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 */
>

Hi Guenter,

On 12/12/2019 10:24 PM, Guenter Roeck wrote:
> On 12/11/19 11:46 AM, Jae Hyun Yoo wrote:
>> This commit adds PECI cputemp hwmon driver.
>>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Jean Delvare <jdelvare@suse.com>
>> Cc: Alan Cox <alan@linux.intel.com>
>> Cc: Andrew Jeffery <andrew@aj.id.au>
>> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
>> Cc: Joel Stanley <joel@jms.id.au>
>> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
>> Cc: Andrew Lunn <andrew@lunn.ch>
>> Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
>> 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>
>> Acked-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>> Changes since v10:
>> - Added Skylake Xeon D support.
>> - Added DTS temperature which is more thermal control friendlier than Die
>>    temperature.
>> - Fixed minor bugs and style issues.
>>
>>   drivers/hwmon/Kconfig        |  14 ++
>>   drivers/hwmon/Makefile       |   1 +
>>   drivers/hwmon/peci-cputemp.c | 448 +++++++++++++++++++++++++++++++++++
>>   drivers/hwmon/peci-hwmon.h   |  46 ++++
>>   4 files changed, 509 insertions(+)
>>   create mode 100644 drivers/hwmon/peci-cputemp.c
>>   create mode 100644 drivers/hwmon/peci-hwmon.h
>>
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 23dfe848979a..b6604759579c 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -1349,6 +1349,20 @@ 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 6db5db9cdc29..d6fea48697af 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -144,6 +144,7 @@ obj-$(CONFIG_SENSORS_NTC_THERMISTOR)    += 
>> ntc_thermistor.o
>>   obj-$(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..70ced9f9299f
>> --- /dev/null
>> +++ b/drivers/hwmon/peci-cputemp.c
>> @@ -0,0 +1,448 @@
>> +// 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 CORETEMP_CHANNEL_NUMS  CORE_NUMS_MAX
> 
> Why not just use CORE_NUMS_MAX ?

For better readability in below code to represent max core numbers
as core temp channel numbers. If you don't like it, I'll use
CORE_NUMS_MAX as it is for the core temp channel numbers.

>> +#define CPUTEMP_CHANNEL_NUMS   (DEFAULT_CHANNEL_NUMS + 
>> CORETEMP_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 core[CORETEMP_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;
>> +};
>> +
>> +enum cputemp_channels {
>> +    channel_die,
>> +    channel_dts,
>> +    channel_tcontrol,
>> +    channel_tthrottle,
>> +    channel_tjmax,
>> +    channel_core,
>> +};
>> +
>> +static const u32 config_table[DEFAULT_CHANNEL_NUMS + 1] = {
>> +    /* 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 | HWMON_T_MAX | HWMON_T_CRIT |
>> +    HWMON_T_CRIT_HYST,
>> +};
>> +
>> +static const char *cputemp_label[CPUTEMP_CHANNEL_NUMS] = {
>> +    "Die",
>> +    "DTS",
>> +    "Tcontrol",
>> +    "Tthrottle",
>> +    "Tjmax",
>> +    "Core 0", "Core 1", "Core 2", "Core 3",
>> +    "Core 4", "Core 5", "Core 6", "Core 7",
>> +    "Core 8", "Core 9", "Core 10", "Core 11",
>> +    "Core 12", "Core 13", "Core 14", "Core 15",
>> +    "Core 16", "Core 17", "Core 18", "Core 19",
>> +    "Core 20", "Core 21", "Core 22", "Core 23",
>> +    "Core 24", "Core 25", "Core 26", "Core 27",
>> +};
>> +
> 
> What happens if CPUTEMP_CHANNEL_NUMS is increased in the future,
> and some of this array includes NULL pointers because this file
> doesn't track CORE_NUMS_MAX ?

Okay. It's reasonable concern. I'll fix it to make this driver generate
the core temp label strings dynamically based on detected CPU generation
information.

>> +static s32 ten_dot_six_to_millidegree(s32 val)
>> +{
>> +    return ((val ^ 0x8000) - 0x8000) * 1000 / 64;
> 
> Normally I suggest to use DIV_ROUND_CLOSEST in situations like this
> to improve rounding, but ultimately that is your call.

This is for conversion of 16-bit signed 10.6
(10 bits signed decimal, 6 bits fractional) format to 32-bits signed
integer in millidegree units. It's right as it is.

>> +}
>> +
>> +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 = (pkg_cfg[1] << 8) | pkg_cfg[0];
>> +
>> +    /**
>> +     * 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_core_temp(struct peci_cputemp *priv, int core_index)
>> +{
>> +    s32 core_dts_margin;
>> +    u8  pkg_cfg[4];
>> +    int ret;
>> +
>> +    if (!peci_sensor_need_update(&priv->temp.core[core_index]))
>> +        return 0;
>> +
>> +    ret = peci_client_read_package_config(priv->mgr,
>> +                          PECI_MBX_INDEX_PER_CORE_DTS_TEMP,
>> +                          core_index, pkg_cfg);
>> +    if (ret)
>> +        return ret;
>> +
>> +    core_dts_margin = le16_to_cpup((__le16 *)pkg_cfg);
>> +
> 
> Any special readon for using the helper function here but not
> above ?

Ah, I have to use le16_to_cpup for the above one too. Thanks!

Thanks a lot for your review!

-Jae