diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 2bfbcc033d59..2b4342abc0a7 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1976,7 +1976,7 @@ config SENSORS_SL28CPLD config SENSORS_SBTSI tristate "Emulated SB-TSI temperature sensor" - depends on I2C + depends on AMD_SBTSI help If you say yes here you get support for emulated temperature sensors on AMD SoCs with SB-TSI interface connected to a BMC device. diff --git a/drivers/hwmon/sbtsi_temp.c b/drivers/hwmon/sbtsi_temp.c index c28f8625cd3a..28258bf49922 100644 --- a/drivers/hwmon/sbtsi_temp.c +++ b/drivers/hwmon/sbtsi_temp.c @@ -7,13 +7,12 @@ * Copyright (c) 2020, Kun Yi */ +#include #include -#include -#include #include +#include #include -#include -#include +#include /* * SB-TSI registers only support SMBus byte data access. "_INT" registers are @@ -22,39 +21,17 @@ */ #define SBTSI_REG_TEMP_INT 0x01 /* RO */ #define SBTSI_REG_STATUS 0x02 /* RO */ -#define SBTSI_REG_CONFIG 0x03 /* RO */ #define SBTSI_REG_TEMP_HIGH_INT 0x07 /* RW */ #define SBTSI_REG_TEMP_LOW_INT 0x08 /* RW */ #define SBTSI_REG_TEMP_DEC 0x10 /* RW */ #define SBTSI_REG_TEMP_HIGH_DEC 0x13 /* RW */ #define SBTSI_REG_TEMP_LOW_DEC 0x14 /* RW */ -/* - * Bit for reporting value with temperature measurement range. - * bit == 0: Use default temperature range (0C to 255.875C). - * bit == 1: Use extended temperature range (-49C to +206.875C). - */ -#define SBTSI_CONFIG_EXT_RANGE_SHIFT 2 -/* - * ReadOrder bit specifies the reading order of integer and decimal part of - * CPU temperature for atomic reads. If bit == 0, reading integer part triggers - * latching of the decimal part, so integer part should be read first. - * If bit == 1, read order should be reversed. - */ -#define SBTSI_CONFIG_READ_ORDER_SHIFT 5 - #define SBTSI_TEMP_EXT_RANGE_ADJ 49000 #define SBTSI_TEMP_MIN 0 #define SBTSI_TEMP_MAX 255875 -/* Each client has this additional data */ -struct sbtsi_data { - struct i2c_client *client; - bool ext_range_mode; - bool read_order; -}; - /* * From SB-TSI spec: CPU temperature readings and limit registers encode the * temperature in increments of 0.125 from 0 to 255.875. The "high byte" @@ -195,55 +172,33 @@ static const struct hwmon_chip_info sbtsi_chip_info = { .info = sbtsi_info, }; -static int sbtsi_probe(struct i2c_client *client) +static int sbtsi_probe(struct auxiliary_device *adev, + const struct auxiliary_device_id *id) { - struct device *dev = &client->dev; + struct sbtsi_data *data = dev_get_drvdata(adev->dev.parent); + struct device *dev = &adev->dev; struct device *hwmon_dev; - struct sbtsi_data *data; - int err; - data = devm_kzalloc(dev, sizeof(struct sbtsi_data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - data->client = client; - - err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG); - if (err < 0) - return err; - data->ext_range_mode = FIELD_GET(BIT(SBTSI_CONFIG_EXT_RANGE_SHIFT), err); - data->read_order = FIELD_GET(BIT(SBTSI_CONFIG_READ_ORDER_SHIFT), err); - - hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, + hwmon_dev = devm_hwmon_device_register_with_info(dev, "sbtsi", data, &sbtsi_chip_info, NULL); return PTR_ERR_OR_ZERO(hwmon_dev); } -static const struct i2c_device_id sbtsi_id[] = { - { .name = "sbtsi" }, +static const struct auxiliary_device_id sbtsi_id[] = { + { .name = AMD_SBTSI_ADEV "." AMD_SBTSI_AUX_HWMON }, { } }; -MODULE_DEVICE_TABLE(i2c, sbtsi_id); +MODULE_DEVICE_TABLE(auxiliary, sbtsi_id); -static const struct of_device_id __maybe_unused sbtsi_of_match[] = { - { - .compatible = "amd,sbtsi", - }, - { }, -}; -MODULE_DEVICE_TABLE(of, sbtsi_of_match); - -static struct i2c_driver sbtsi_driver = { +static struct auxiliary_driver sbtsi_driver = { .driver = { .name = "sbtsi", - .of_match_table = of_match_ptr(sbtsi_of_match), }, .probe = sbtsi_probe, .id_table = sbtsi_id, }; - -module_i2c_driver(sbtsi_driver); +module_auxiliary_driver(sbtsi_driver); MODULE_AUTHOR("Kun Yi "); MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); diff --git a/drivers/misc/amd-sbi/Kconfig b/drivers/misc/amd-sbi/Kconfig index 30e7fad7356c..512251690e0e 100644 --- a/drivers/misc/amd-sbi/Kconfig +++ b/drivers/misc/amd-sbi/Kconfig @@ -20,3 +20,16 @@ config AMD_SBRMI_HWMON This provides support for RMI device hardware monitoring. If enabled, a hardware monitoring device will be created for each socket in the system. + +config AMD_SBTSI + tristate "AMD side band TSI support" + depends on I2C + depends on ARM || ARM64 || COMPILE_TEST + select AUXILIARY_BUS + help + Enables support for the AMD SB-TSI (Side Band Temperature Sensor + Interface) driver, which provides access to emulated CPU temperature + sensors on AMD SoCs via an I2C connected BMC device. + + This driver can also be built as a module. If so, the module will + be called sbtsi. diff --git a/drivers/misc/amd-sbi/Makefile b/drivers/misc/amd-sbi/Makefile index 38eaaa651fd9..28f95b9e204f 100644 --- a/drivers/misc/amd-sbi/Makefile +++ b/drivers/misc/amd-sbi/Makefile @@ -2,3 +2,6 @@ sbrmi-i2c-objs += rmi-i2c.o rmi-core.o sbrmi-i2c-$(CONFIG_AMD_SBRMI_HWMON) += rmi-hwmon.o obj-$(CONFIG_AMD_SBRMI_I2C) += sbrmi-i2c.o +# SBTSI Configuration +sbtsi-objs += tsi.o +obj-$(CONFIG_AMD_SBTSI) += sbtsi.o diff --git a/drivers/misc/amd-sbi/tsi.c b/drivers/misc/amd-sbi/tsi.c new file mode 100644 index 000000000000..67d08df28429 --- /dev/null +++ b/drivers/misc/amd-sbi/tsi.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * tsi.c - AMD SBTSI I2C core driver. Probes the SBTSI device over I2C + * and publishes an auxiliary device on the auxiliary bus. + * + * Copyright (C) 2026 Advanced Micro Devices, Inc. + */ + +#include +#include +#include +#include +#include +#include + +#define SBTSI_REG_CONFIG 0x03 /* RO */ + +/* + * Bit for reporting value with temperature measurement range. + * bit == 0: Use default temperature range (0C to 255.875C). + * bit == 1: Use extended temperature range (-49C to +206.875C). + */ +#define SBTSI_CONFIG_EXT_RANGE_SHIFT 2 + +/* + * ReadOrder bit specifies the reading order of integer and decimal part of + * CPU temperature for atomic reads. If bit == 0, reading integer part triggers + * latching of the decimal part, so integer part should be read first. + */ +#define SBTSI_CONFIG_READ_ORDER_SHIFT 5 + +static void sbtsi_adev_release(struct device *dev) +{ + kfree(to_auxiliary_dev(dev)); +} + +static void sbtsi_unregister_hwmon_adev(void *_adev) +{ + struct auxiliary_device *adev = _adev; + + auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); +} + +/* + * Create and publish an auxiliary device. The hwmon driver in + * drivers/hwmon/sbtsi_temp.c binds to this device. + * + * @dev: I2C device (parent of the auxiliary device) + * @dev_addr: I2C address — used as the auxiliary device instance ID so that + * each socket gets a unique name. + */ +static int sbtsi_create_hwmon_adev(struct device *dev, u8 dev_addr) +{ + struct auxiliary_device *adev; + int ret; + + adev = kzalloc_obj(*adev); + if (!adev) + return -ENOMEM; + + adev->name = AMD_SBTSI_AUX_HWMON; + adev->id = dev_addr; + adev->dev.parent = dev; + adev->dev.release = sbtsi_adev_release; + + ret = auxiliary_device_init(adev); + if (ret) { + kfree(adev); + return ret; + } + + ret = __auxiliary_device_add(adev, AMD_SBTSI_ADEV); + if (ret) { + auxiliary_device_uninit(adev); + return ret; + } + + return devm_add_action_or_reset(dev, sbtsi_unregister_hwmon_adev, adev); +} + +static int sbtsi_i2c_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct sbtsi_data *data; + int err; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG); + if (err < 0) + return err; + data->ext_range_mode = FIELD_GET(BIT(SBTSI_CONFIG_EXT_RANGE_SHIFT), err); + data->read_order = FIELD_GET(BIT(SBTSI_CONFIG_READ_ORDER_SHIFT), err); + + dev_set_drvdata(dev, data); + /* In a multi-socket system, devices that are otherwise identical do not + * share the same static address; each instance resides at a unique I2C + * client address on the same or different bus. Use the I2C client + * address as the auxiliary device instance ID to ensure each socket + * receives a distinct auxiliary device name. + */ + return sbtsi_create_hwmon_adev(dev, client->addr); +} + +static const struct i2c_device_id sbtsi_id[] = { + { .name = "sbtsi" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, sbtsi_id); + +static const struct of_device_id __maybe_unused sbtsi_of_match[] = { + { + .compatible = "amd,sbtsi", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, sbtsi_of_match); + +static struct i2c_driver sbtsi_driver = { + .driver = { + .name = "sbtsi-i2c", + .of_match_table = of_match_ptr(sbtsi_of_match), + }, + .probe = sbtsi_i2c_probe, + .id_table = sbtsi_id, +}; + +module_i2c_driver(sbtsi_driver); + +MODULE_DESCRIPTION("AMD SB-TSI I2C core driver"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/misc/tsi.h b/include/linux/misc/tsi.h new file mode 100644 index 000000000000..befdc2d14160 --- /dev/null +++ b/include/linux/misc/tsi.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * AMD SBTSI shared data structure and auxiliary bus definitions. + * + * Copyright (C) 2026 Advanced Micro Devices, Inc. + */ + +#ifndef _LINUX_MISC_TSI_H_ +#define _LINUX_MISC_TSI_H_ + +#include +#include + +/** + * struct sbtsi_data - driver private data for an AMD SB-TSI device + * @client: underlying I2C client + * @ext_range_mode: sensor uses extended temperature range + * @read_order: if set, decimal part must be read before integer part + */ +struct sbtsi_data { + struct i2c_client *client; + bool ext_range_mode; + bool read_order; +}; + +/* + * Name of the auxiliary device published on the auxiliary bus by the core + * driver. The full device name is "amd-sbtsi.temp-sensor.". where + * is the auxiliary device instance id. + */ +#define AMD_SBTSI_ADEV "amd-sbtsi" +#define AMD_SBTSI_AUX_HWMON "temp-sensor" + +#endif /* _LINUX_MISC_TSI_H_ */