mlxsw: core: Implement thermal zone

Implement thermal zone for mlxsw based HW. It uses temperature sensor
provided by ASIC (the same as mlxsw hwmon interface) to report current
temp to thermal core. The ASIC's PWM is then used to control speed
of system fans registered as cooling devices.
Signed-off-by: NIvan Vecera <cera@cera.cz>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Kconfig

@@ -19,6 +19,15 @@ config MLXSW_CORE_HWMON
 	---help---
 	  Say Y here if you want to expose HWMON interface on mlxsw devices.
 
+config MLXSW_CORE_THERMAL
+	bool "Thermal zone support for Mellanox Technologies Switch ASICs"
+	depends on MLXSW_CORE && THERMAL
+	depends on !(MLXSW_CORE=y && THERMAL=m)
+	default y
+	---help---
+	 Say Y here if you want to automatically control fans speed according
+	 ambient temperature reported by ASIC.
+
 config MLXSW_PCI
 	tristate "PCI bus implementation for Mellanox Technologies Switch ASICs"
 	depends on PCI && HAS_DMA && HAS_IOMEM && MLXSW_CORE

drivers/net/ethernet/mellanox/mlxsw/Makefile

 obj-$(CONFIG_MLXSW_CORE)	+= mlxsw_core.o
 mlxsw_core-objs			:= core.o
 mlxsw_core-$(CONFIG_MLXSW_CORE_HWMON) += core_hwmon.o
+mlxsw_core-$(CONFIG_MLXSW_CORE_THERMAL) += core_thermal.o
 obj-$(CONFIG_MLXSW_PCI)		+= mlxsw_pci.o
 mlxsw_pci-objs			:= pci.o
 obj-$(CONFIG_MLXSW_I2C)		+= mlxsw_i2c.o

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -131,6 +131,7 @@ struct mlxsw_core {
 	} lag;
 	struct mlxsw_res res;
 	struct mlxsw_hwmon *hwmon;
+	struct mlxsw_thermal *thermal;
 	struct mlxsw_core_port ports[MLXSW_PORT_MAX_PORTS];
 	unsigned long driver_priv[0];
 	/* driver_priv has to be always the last item */
@@ -1162,6 +1163,11 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 	if (err)
 		goto err_hwmon_init;
 
+	err = mlxsw_thermal_init(mlxsw_core, mlxsw_bus_info,
+				 &mlxsw_core->thermal);
+	if (err)
+		goto err_thermal_init;
+
 	if (mlxsw_driver->init) {
 		err = mlxsw_driver->init(mlxsw_core, mlxsw_bus_info);
 		if (err)
@@ -1178,6 +1184,7 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 	if (mlxsw_core->driver->fini)
 		mlxsw_core->driver->fini(mlxsw_core);
 err_driver_init:
+err_thermal_init:
 err_hwmon_init:
 	devlink_unregister(devlink);
 err_devlink_register:
@@ -1204,6 +1211,7 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core)
 	mlxsw_core_debugfs_fini(mlxsw_core);
 	if (mlxsw_core->driver->fini)
 		mlxsw_core->driver->fini(mlxsw_core);
+	mlxsw_thermal_fini(mlxsw_core->thermal);
 	devlink_unregister(devlink);
 	mlxsw_emad_fini(mlxsw_core);
 	mlxsw_core->bus->fini(mlxsw_core->bus_priv);

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -321,4 +321,28 @@ static inline int mlxsw_hwmon_init(struct mlxsw_core *mlxsw_core,
 
 #endif
 
+struct mlxsw_thermal;
+
+#ifdef CONFIG_MLXSW_CORE_THERMAL
+
+int mlxsw_thermal_init(struct mlxsw_core *mlxsw_core,
+		       const struct mlxsw_bus_info *mlxsw_bus_info,
+		       struct mlxsw_thermal **p_thermal);
+void mlxsw_thermal_fini(struct mlxsw_thermal *thermal);
+
+#else
+
+static inline int mlxsw_thermal_init(struct mlxsw_core *mlxsw_core,
+				     const struct mlxsw_bus_info *mlxsw_bus_info,
+				     struct mlxsw_thermal **p_thermal)
+{
+	return 0;
+}
+
+static inline void mlxsw_thermal_fini(struct mlxsw_thermal *thermal)
+{
+}
+
+#endif
+
 #endif

drivers/net/ethernet/mellanox/mlxsw/core_thermal.c

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
+ * Copyright (c) 2016 Ivan Vecera <cera@cera.cz>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+#include <linux/err.h>
+
+#include "core.h"
+
+#define MLXSW_THERMAL_POLL_INT	1000	/* ms */
+#define MLXSW_THERMAL_MAX_TEMP	110000	/* 110C */
+#define MLXSW_THERMAL_MAX_STATE	10
+#define MLXSW_THERMAL_MAX_DUTY	255
+
+struct mlxsw_thermal_trip {
+	int	type;
+	int	temp;
+	int	min_state;
+	int	max_state;
+};
+
+static const struct mlxsw_thermal_trip default_thermal_trips[] = {
+	{	/* In range - 0-40% PWM */
+		.type		= THERMAL_TRIP_ACTIVE,
+		.temp		= 75000,
+		.min_state	= 0,
+		.max_state	= (4 * MLXSW_THERMAL_MAX_STATE) / 10,
+	},
+	{	/* High - 40-100% PWM */
+		.type		= THERMAL_TRIP_ACTIVE,
+		.temp		= 80000,
+		.min_state	= (4 * MLXSW_THERMAL_MAX_STATE) / 10,
+		.max_state	= MLXSW_THERMAL_MAX_STATE,
+	},
+	{
+		/* Very high - 100% PWM */
+		.type		= THERMAL_TRIP_ACTIVE,
+		.temp		= 85000,
+		.min_state	= MLXSW_THERMAL_MAX_STATE,
+		.max_state	= MLXSW_THERMAL_MAX_STATE,
+	},
+	{	/* Warning */
+		.type		= THERMAL_TRIP_HOT,
+		.temp		= 105000,
+		.min_state	= MLXSW_THERMAL_MAX_STATE,
+		.max_state	= MLXSW_THERMAL_MAX_STATE,
+	},
+	{	/* Critical - soft poweroff */
+		.type		= THERMAL_TRIP_CRITICAL,
+		.temp		= MLXSW_THERMAL_MAX_TEMP,
+		.min_state	= MLXSW_THERMAL_MAX_STATE,
+		.max_state	= MLXSW_THERMAL_MAX_STATE,
+	}
+};
+
+#define MLXSW_THERMAL_NUM_TRIPS	ARRAY_SIZE(default_thermal_trips)
+
+/* Make sure all trips are writable */
+#define MLXSW_THERMAL_TRIP_MASK	(BIT(MLXSW_THERMAL_NUM_TRIPS) - 1)
+
+struct mlxsw_thermal {
+	struct mlxsw_core *core;
+	const struct mlxsw_bus_info *bus_info;
+	struct thermal_zone_device *tzdev;
+	struct thermal_cooling_device *cdevs[MLXSW_MFCR_PWMS_MAX];
+	struct mlxsw_thermal_trip trips[MLXSW_THERMAL_NUM_TRIPS];
+	enum thermal_device_mode mode;
+};
+
+static inline u8 mlxsw_state_to_duty(int state)
+{
+	return DIV_ROUND_CLOSEST(state * MLXSW_THERMAL_MAX_DUTY,
+				 MLXSW_THERMAL_MAX_STATE);
+}
+
+static inline int mlxsw_duty_to_state(u8 duty)
+{
+	return DIV_ROUND_CLOSEST(duty * MLXSW_THERMAL_MAX_STATE,
+				 MLXSW_THERMAL_MAX_DUTY);
+}
+
+static int mlxsw_get_cooling_device_idx(struct mlxsw_thermal *thermal,
+					struct thermal_cooling_device *cdev)
+{
+	int i;
+
+	for (i = 0; i < MLXSW_MFCR_PWMS_MAX; i++)
+		if (thermal->cdevs[i] == cdev)
+			return i;
+
+	return -ENODEV;
+}
+
+static int mlxsw_thermal_bind(struct thermal_zone_device *tzdev,
+			      struct thermal_cooling_device *cdev)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+	struct device *dev = thermal->bus_info->dev;
+	int i, err;
+
+	/* If the cooling device is one of ours bind it */
+	if (mlxsw_get_cooling_device_idx(thermal, cdev) < 0)
+		return 0;
+
+	for (i = 0; i < MLXSW_THERMAL_NUM_TRIPS; i++) {
+		const struct mlxsw_thermal_trip *trip = &thermal->trips[i];
+
+		err = thermal_zone_bind_cooling_device(tzdev, i, cdev,
+						       trip->max_state,
+						       trip->min_state,
+						       THERMAL_WEIGHT_DEFAULT);
+		if (err < 0) {
+			dev_err(dev, "Failed to bind cooling device to trip %d\n", i);
+			return err;
+		}
+	}
+	return 0;
+}
+
+static int mlxsw_thermal_unbind(struct thermal_zone_device *tzdev,
+				struct thermal_cooling_device *cdev)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+	struct device *dev = thermal->bus_info->dev;
+	int i;
+	int err;
+
+	/* If the cooling device is our one unbind it */
+	if (mlxsw_get_cooling_device_idx(thermal, cdev) < 0)
+		return 0;
+
+	for (i = 0; i < MLXSW_THERMAL_NUM_TRIPS; i++) {
+		err = thermal_zone_unbind_cooling_device(tzdev, i, cdev);
+		if (err < 0) {
+			dev_err(dev, "Failed to unbind cooling device\n");
+			return err;
+		}
+	}
+	return 0;
+}
+
+static int mlxsw_thermal_get_mode(struct thermal_zone_device *tzdev,
+				  enum thermal_device_mode *mode)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+
+	*mode = thermal->mode;
+
+	return 0;
+}
+
+static int mlxsw_thermal_set_mode(struct thermal_zone_device *tzdev,
+				  enum thermal_device_mode mode)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+
+	mutex_lock(&tzdev->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		tzdev->polling_delay = MLXSW_THERMAL_POLL_INT;
+	else
+		tzdev->polling_delay = 0;
+
+	mutex_unlock(&tzdev->lock);
+
+	thermal->mode = mode;
+	thermal_zone_device_update(tzdev, THERMAL_EVENT_UNSPECIFIED);
+
+	return 0;
+}
+
+static int mlxsw_thermal_get_temp(struct thermal_zone_device *tzdev,
+				  int *p_temp)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+	struct device *dev = thermal->bus_info->dev;
+	char mtmp_pl[MLXSW_REG_MTMP_LEN];
+	unsigned int temp;
+	int err;
+
+	mlxsw_reg_mtmp_pack(mtmp_pl, 0, false, false);
+
+	err = mlxsw_reg_query(thermal->core, MLXSW_REG(mtmp), mtmp_pl);
+	if (err) {
+		dev_err(dev, "Failed to query temp sensor\n");
+		return err;
+	}
+	mlxsw_reg_mtmp_unpack(mtmp_pl, &temp, NULL, NULL);
+
+	*p_temp = (int) temp;
+	return 0;
+}
+
+static int mlxsw_thermal_get_trip_type(struct thermal_zone_device *tzdev,
+				       int trip,
+				       enum thermal_trip_type *p_type)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+
+	if (trip < 0 || trip >= MLXSW_THERMAL_NUM_TRIPS)
+		return -EINVAL;
+
+	*p_type = thermal->trips[trip].type;
+	return 0;
+}
+
+static int mlxsw_thermal_get_trip_temp(struct thermal_zone_device *tzdev,
+				       int trip, int *p_temp)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+
+	if (trip < 0 || trip >= MLXSW_THERMAL_NUM_TRIPS)
+		return -EINVAL;
+
+	*p_temp = thermal->trips[trip].temp;
+	return 0;
+}
+
+static int mlxsw_thermal_set_trip_temp(struct thermal_zone_device *tzdev,
+				       int trip, int temp)
+{
+	struct mlxsw_thermal *thermal = tzdev->devdata;
+
+	if (trip < 0 || trip >= MLXSW_THERMAL_NUM_TRIPS ||
+	    temp > MLXSW_THERMAL_MAX_TEMP)
+		return -EINVAL;
+
+	thermal->trips[trip].temp = temp;
+	return 0;
+}
+
+static struct thermal_zone_device_ops mlxsw_thermal_ops = {
+	.bind = mlxsw_thermal_bind,
+	.unbind = mlxsw_thermal_unbind,
+	.get_mode = mlxsw_thermal_get_mode,
+	.set_mode = mlxsw_thermal_set_mode,
+	.get_temp = mlxsw_thermal_get_temp,
+	.get_trip_type	= mlxsw_thermal_get_trip_type,
+	.get_trip_temp	= mlxsw_thermal_get_trip_temp,
+	.set_trip_temp	= mlxsw_thermal_set_trip_temp,
+};
+
+static int mlxsw_thermal_get_max_state(struct thermal_cooling_device *cdev,
+				       unsigned long *p_state)
+{
+	*p_state = MLXSW_THERMAL_MAX_STATE;
+	return 0;
+}
+
+static int mlxsw_thermal_get_cur_state(struct thermal_cooling_device *cdev,
+				       unsigned long *p_state)
+
+{
+	struct mlxsw_thermal *thermal = cdev->devdata;
+	struct device *dev = thermal->bus_info->dev;
+	char mfsc_pl[MLXSW_REG_MFSC_LEN];
+	int err, idx;
+	u8 duty;
+
+	idx = mlxsw_get_cooling_device_idx(thermal, cdev);
+	if (idx < 0)
+		return idx;
+
+	mlxsw_reg_mfsc_pack(mfsc_pl, idx, 0);
+	err = mlxsw_reg_query(thermal->core, MLXSW_REG(mfsc), mfsc_pl);
+	if (err) {
+		dev_err(dev, "Failed to query PWM duty\n");
+		return err;
+	}
+
+	duty = mlxsw_reg_mfsc_pwm_duty_cycle_get(mfsc_pl);
+	*p_state = mlxsw_duty_to_state(duty);
+	return 0;
+}
+
+static int mlxsw_thermal_set_cur_state(struct thermal_cooling_device *cdev,
+				       unsigned long state)
+
+{
+	struct mlxsw_thermal *thermal = cdev->devdata;
+	struct device *dev = thermal->bus_info->dev;
+	char mfsc_pl[MLXSW_REG_MFSC_LEN];
+	int err, idx;
+
+	idx = mlxsw_get_cooling_device_idx(thermal, cdev);
+	if (idx < 0)
+		return idx;
+
+	mlxsw_reg_mfsc_pack(mfsc_pl, idx, mlxsw_state_to_duty(state));
+	err = mlxsw_reg_write(thermal->core, MLXSW_REG(mfsc), mfsc_pl);
+	if (err) {
+		dev_err(dev, "Failed to write PWM duty\n");
+		return err;
+	}
+	return 0;
+}
+
+static const struct thermal_cooling_device_ops mlxsw_cooling_ops = {
+	.get_max_state	= mlxsw_thermal_get_max_state,
+	.get_cur_state	= mlxsw_thermal_get_cur_state,
+	.set_cur_state	= mlxsw_thermal_set_cur_state,
+};
+
+int mlxsw_thermal_init(struct mlxsw_core *core,
+		       const struct mlxsw_bus_info *bus_info,
+		       struct mlxsw_thermal **p_thermal)
+{
+	char mfcr_pl[MLXSW_REG_MFCR_LEN] = { 0 };
+	enum mlxsw_reg_mfcr_pwm_frequency freq;
+	struct device *dev = bus_info->dev;
+	struct mlxsw_thermal *thermal;
+	u16 tacho_active;
+	u8 pwm_active;
+	int err, i;
+
+	thermal = devm_kzalloc(dev, sizeof(*thermal),
+			       GFP_KERNEL);
+	if (!thermal)
+		return -ENOMEM;
+
+	thermal->core = core;
+	thermal->bus_info = bus_info;
+	memcpy(thermal->trips, default_thermal_trips, sizeof(thermal->trips));
+
+	err = mlxsw_reg_query(thermal->core, MLXSW_REG(mfcr), mfcr_pl);
+	if (err) {
+		dev_err(dev, "Failed to probe PWMs\n");
+		goto err_free_thermal;
+	}
+	mlxsw_reg_mfcr_unpack(mfcr_pl, &freq, &tacho_active, &pwm_active);
+
+	for (i = 0; i < MLXSW_MFCR_TACHOS_MAX; i++) {
+		if (tacho_active & BIT(i)) {
+			char mfsl_pl[MLXSW_REG_MFSL_LEN];
+
+			mlxsw_reg_mfsl_pack(mfsl_pl, i, 0, 0);
+
+			/* We need to query the register to preserve maximum */
+			err = mlxsw_reg_query(thermal->core, MLXSW_REG(mfsl),
+					      mfsl_pl);
+			if (err)
+				goto err_free_thermal;
+
+			/* set the minimal RPMs to 0 */
+			mlxsw_reg_mfsl_tach_min_set(mfsl_pl, 0);
+			err = mlxsw_reg_write(thermal->core, MLXSW_REG(mfsl),
+					      mfsl_pl);
+			if (err)
+				goto err_free_thermal;
+		}
+	}
+	for (i = 0; i < MLXSW_MFCR_PWMS_MAX; i++) {
+		if (pwm_active & BIT(i)) {
+			struct thermal_cooling_device *cdev;
+
+			cdev = thermal_cooling_device_register("Fan", thermal,
+							&mlxsw_cooling_ops);
+			if (IS_ERR(cdev)) {
+				err = PTR_ERR(cdev);
+				dev_err(dev, "Failed to register cooling device\n");
+				goto err_unreg_cdevs;
+			}
+			thermal->cdevs[i] = cdev;
+		}
+	}
+
+	thermal->tzdev = thermal_zone_device_register("mlxsw",
+						      MLXSW_THERMAL_NUM_TRIPS,
+						      MLXSW_THERMAL_TRIP_MASK,
+						      thermal,
+						      &mlxsw_thermal_ops,
+						      NULL, 0,
+						      MLXSW_THERMAL_POLL_INT);
+	if (IS_ERR(thermal->tzdev)) {
+		err = PTR_ERR(thermal->tzdev);
+		dev_err(dev, "Failed to register thermal zone\n");
+		goto err_unreg_cdevs;
+	}
+
+	thermal->mode = THERMAL_DEVICE_ENABLED;
+	*p_thermal = thermal;
+	return 0;
+err_unreg_cdevs:
+	for (i = 0; i < MLXSW_MFCR_PWMS_MAX; i++)
+		if (thermal->cdevs[i])
+			thermal_cooling_device_unregister(thermal->cdevs[i]);
+err_free_thermal:
+	devm_kfree(dev, thermal);
+	return err;
+}
+
+void mlxsw_thermal_fini(struct mlxsw_thermal *thermal)
+{
+	int i;
+
+	if (thermal->tzdev) {
+		thermal_zone_device_unregister(thermal->tzdev);
+		thermal->tzdev = NULL;
+	}
+
+	for (i = 0; i < MLXSW_MFCR_PWMS_MAX; i++) {
+		if (thermal->cdevs[i]) {
+			thermal_cooling_device_unregister(thermal->cdevs[i]);
+			thermal->cdevs[i] = NULL;
+		}
+	}
+
+	devm_kfree(thermal->bus_info->dev, thermal);
+}