From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF183C4361B for ; Sat, 12 Dec 2020 16:45:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E0F4222BB for ; Sat, 12 Dec 2020 16:45:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726579AbgLLQp0 (ORCPT ); Sat, 12 Dec 2020 11:45:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726136AbgLLQpZ (ORCPT ); Sat, 12 Dec 2020 11:45:25 -0500 Received: from mail-ot1-x342.google.com (mail-ot1-x342.google.com [IPv6:2607:f8b0:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BC44C0613CF; Sat, 12 Dec 2020 08:44:45 -0800 (PST) Received: by mail-ot1-x342.google.com with SMTP id q25so11331703otn.10; Sat, 12 Dec 2020 08:44:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=EeyWaaX7RaAeCqpa7o4/zDZt2SSccBzU1v5h8IB6W5o=; b=HEUdfUqdydbETpeZxTzGUALNRH3jCFKbmXY/+3gLw89/U7sOg5NI3DqY/dAsjxU68p APrnO6GoYqhgxP7fsYk4ZJ9eQO4gsXwaO33Oa/NgYSVSFN2H7xh3zHm0kUREH9H+/PxH uw7nOZNc30mNj7mB332PMR8bf9YfPCytU8i6yqfp56Eu/kBv7gBhAOB1ZxaJR3nCxJLC 7THds3wU6UYj8BuwjcyrapDWrwXM2D82qsgWJmVqll2dDgfcr++DllmXZcJsyhQuzB65 EcgL1cT6a0Wfu6FJ3TbISIMhJAuFBTBZNkBN2hQzRkLfn3h075yHGu3UtxlNVXEVfQfX cYiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=EeyWaaX7RaAeCqpa7o4/zDZt2SSccBzU1v5h8IB6W5o=; b=Zpj0AT5w5SdpgcU7myj/ToOD6hdx8uQr0hDEi4E8t/t/mXKGvEa9Dddas+e3PNLOif RtUjVHwzNsVbJHarht6dYp9Bk4rB8Ei/GvPNxbHUUDq+vDPAC52g2uN0nUgoCKTUMX2f Cfxy7GuDG8qzRkw+IQDXKj8Irv8g93jrnFX+t34ki9oppMHIUIzeH650Sj48sNuPNbnb VjA6ZGZEuUlg2dk9gIp5QTm6jyNvNDQOjTssi3IeyhRev6bfk8am+UH/bVI2YtRq42Ek S8IZHEfBaDO29Q4XVM5QFzFewZupmR+Q9977egMJcVBA8VG/HsbpSYgZfpdhPtArXaI7 +r2g== X-Gm-Message-State: AOAM530rTNrE3ixRUdsMegsBgyKB/ATAcdeXsf89F2JIlFZCYNla8C+M clM7SU1ySvn2JhXUcye9YDWLDw3My2U= X-Google-Smtp-Source: ABdhPJw4y1wis5au6q+ezkP84nlSwIcqaaI4nuEEp2NoIYnuQ42FF+zpknofyu4wQwWmPiViqSb62w== X-Received: by 2002:a9d:6f91:: with SMTP id h17mr14204381otq.104.1607791484758; Sat, 12 Dec 2020 08:44:44 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id f25sm32691oou.39.2020.12.12.08.44.44 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sat, 12 Dec 2020 08:44:44 -0800 (PST) Sender: Guenter Roeck Date: Sat, 12 Dec 2020 08:44:43 -0800 From: Guenter Roeck To: Kun Yi Cc: jdelvare@suse.com, robh+dt@kernel.org, mark.rutland@arm.com, supreeth.venkatesh@amd.com, openbmc@lists.ozlabs.org, linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH linux hwmon-next v5 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Message-ID: <20201212163628.GA28946@roeck-us.net> References: <20201211215427.3281681-1-kunyi@google.com> <20201211215427.3281681-2-kunyi@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201211215427.3281681-2-kunyi@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Fri, Dec 11, 2020 at 01:54:25PM -0800, Kun Yi wrote: > SB Temperature Sensor Interface (SB-TSI) is an SMBus compatible > interface that reports AMD SoC's Ttcl (normalized temperature), > and resembles a typical 8-pin remote temperature sensor's I2C interface > to BMC. > > This commit adds basic support using this interface to read CPU > temperature, and read/write high/low CPU temp thresholds. > > To instantiate this driver on an AMD CPU with SB-TSI > support, the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. The i2c address is specified in > Section 6.3.1 of the spec [1]: The SB-TSI address is normally 98h for > socket 0 and 90h for socket 1, but it could vary based on hardware address > select pins. > > [1]: https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf > > Test status: tested reading temp1_input, and reading/writing > temp1_max/min. > > Signed-off-by: Kun Yi Applied. Thanks, Guenter > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbtsi_temp.c | 250 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 261 insertions(+) > create mode 100644 drivers/hwmon/sbtsi_temp.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 3c059fc23cd6..3d6a809700ae 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1522,6 +1522,16 @@ config SENSORS_SL28CPLD > This driver can also be built as a module. If so, the module > will be called sl28cpld-hwmon. > > +config SENSORS_SBTSI > + tristate "Emulated SB-TSI temperature sensor" > + depends on I2C > + 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. > + > + This driver can also be built as a module. If so, the module will > + be called sbtsi_temp. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 01ca5d3fbad4..ee8c037919da 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -160,6 +160,7 @@ obj-$(CONFIG_SENSORS_POWR1220) += powr1220.o > obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > +obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbtsi_temp.c b/drivers/hwmon/sbtsi_temp.c > new file mode 100644 > index 000000000000..e35357c48b8e > --- /dev/null > +++ b/drivers/hwmon/sbtsi_temp.c > @@ -0,0 +1,250 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbtsi_temp.c - hwmon driver for a SBI Temperature Sensor Interface (SB-TSI) > + * compliant AMD SoC temperature device. > + * > + * Copyright (c) 2020, Google Inc. > + * Copyright (c) 2020, Kun Yi > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* > + * SB-TSI registers only support SMBus byte data access. "_INT" registers are > + * the integer part of a temperature value or limit, and "_DEC" registers are > + * corresponding decimal parts. > + */ > +#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 */ > + > +#define SBTSI_CONFIG_READ_ORDER_SHIFT 5 > + > +#define SBTSI_TEMP_MIN 0 > +#define SBTSI_TEMP_MAX 255875 > + > +/* Each client has this additional data */ > +struct sbtsi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* > + * 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" > + * register encodes the base-2 of the integer portion, and the upper 3 bits of > + * the "low byte" encode in base-2 the decimal portion. > + * > + * e.g. INT=0x19, DEC=0x20 represents 25.125 degrees Celsius > + * > + * Therefore temperature in millidegree Celsius = > + * (INT + DEC / 256) * 1000 = (INT * 8 + DEC / 32) * 125 > + */ > +static inline int sbtsi_reg_to_mc(s32 integer, s32 decimal) > +{ > + return ((integer << 3) + (decimal >> 5)) * 125; > +} > + > +/* > + * Inversely, given temperature in millidegree Celsius > + * INT = (TEMP / 125) / 8 > + * DEC = ((TEMP / 125) % 8) * 32 > + * Caller have to make sure temp doesn't exceed 255875, the max valid value. > + */ > +static inline void sbtsi_mc_to_reg(s32 temp, u8 *integer, u8 *decimal) > +{ > + temp /= 125; > + *integer = temp >> 3; > + *decimal = (temp & 0x7) << 5; > +} > + > +static int sbtsi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct sbtsi_data *data = dev_get_drvdata(dev); > + s32 temp_int, temp_dec; > + int err; > + > + switch (attr) { > + case hwmon_temp_input: > + /* > + * ReadOrder bit specifies the reading order of integer and > + * decimal part of CPU temp 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. > + */ > + err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG); > + if (err < 0) > + return err; > + > + mutex_lock(&data->lock); > + if (err & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT)) { > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT); > + } else { > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC); > + } > + mutex_unlock(&data->lock); > + break; > + case hwmon_temp_max: > + mutex_lock(&data->lock); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_DEC); > + mutex_unlock(&data->lock); > + break; > + case hwmon_temp_min: > + mutex_lock(&data->lock); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_DEC); > + mutex_unlock(&data->lock); > + break; > + default: > + return -EINVAL; > + } > + > + > + if (temp_int < 0) > + return temp_int; > + if (temp_dec < 0) > + return temp_dec; > + > + *val = sbtsi_reg_to_mc(temp_int, temp_dec); > + > + return 0; > +} > + > +static int sbtsi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct sbtsi_data *data = dev_get_drvdata(dev); > + int reg_int, reg_dec, err; > + u8 temp_int, temp_dec; > + > + switch (attr) { > + case hwmon_temp_max: > + reg_int = SBTSI_REG_TEMP_HIGH_INT; > + reg_dec = SBTSI_REG_TEMP_HIGH_DEC; > + break; > + case hwmon_temp_min: > + reg_int = SBTSI_REG_TEMP_LOW_INT; > + reg_dec = SBTSI_REG_TEMP_LOW_DEC; > + break; > + default: > + return -EINVAL; > + } > + > + val = clamp_val(val, SBTSI_TEMP_MIN, SBTSI_TEMP_MAX); > + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); > + > + mutex_lock(&data->lock); > + err = i2c_smbus_write_byte_data(data->client, reg_int, temp_int); > + if (err) > + goto exit; > + > + err = i2c_smbus_write_byte_data(data->client, reg_dec, temp_dec); > +exit: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static umode_t sbtsi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_temp: > + switch (attr) { > + case hwmon_temp_input: > + return 0444; > + case hwmon_temp_min: > + return 0644; > + case hwmon_temp_max: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbtsi_info[] = { > + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), > + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbtsi_hwmon_ops = { > + .is_visible = sbtsi_is_visible, > + .read = sbtsi_read, > + .write = sbtsi_write, > +}; > + > +static const struct hwmon_chip_info sbtsi_chip_info = { > + .ops = &sbtsi_hwmon_ops, > + .info = sbtsi_info, > +}; > + > +static int sbtsi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbtsi_data *data; > + > + data = devm_kzalloc(dev, sizeof(struct sbtsi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, &sbtsi_chip_info, > + NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct i2c_device_id sbtsi_id[] = { > + {"sbtsi", 0}, > + {} > +}; > +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 = { > + .class = I2C_CLASS_HWMON, > + .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_AUTHOR("Kun Yi "); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); 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charset=us-ascii Content-Disposition: inline In-Reply-To: <20201211215427.3281681-2-kunyi@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-hwmon@vger.kernel.org, jdelvare@suse.com, devicetree@vger.kernel.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, supreeth.venkatesh@amd.com Errors-To: openbmc-bounces+openbmc=archiver.kernel.org@lists.ozlabs.org Sender: "openbmc" On Fri, Dec 11, 2020 at 01:54:25PM -0800, Kun Yi wrote: > SB Temperature Sensor Interface (SB-TSI) is an SMBus compatible > interface that reports AMD SoC's Ttcl (normalized temperature), > and resembles a typical 8-pin remote temperature sensor's I2C interface > to BMC. > > This commit adds basic support using this interface to read CPU > temperature, and read/write high/low CPU temp thresholds. > > To instantiate this driver on an AMD CPU with SB-TSI > support, the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. The i2c address is specified in > Section 6.3.1 of the spec [1]: The SB-TSI address is normally 98h for > socket 0 and 90h for socket 1, but it could vary based on hardware address > select pins. > > [1]: https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf > > Test status: tested reading temp1_input, and reading/writing > temp1_max/min. > > Signed-off-by: Kun Yi Applied. Thanks, Guenter > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbtsi_temp.c | 250 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 261 insertions(+) > create mode 100644 drivers/hwmon/sbtsi_temp.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 3c059fc23cd6..3d6a809700ae 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1522,6 +1522,16 @@ config SENSORS_SL28CPLD > This driver can also be built as a module. If so, the module > will be called sl28cpld-hwmon. > > +config SENSORS_SBTSI > + tristate "Emulated SB-TSI temperature sensor" > + depends on I2C > + 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. > + > + This driver can also be built as a module. If so, the module will > + be called sbtsi_temp. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 01ca5d3fbad4..ee8c037919da 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -160,6 +160,7 @@ obj-$(CONFIG_SENSORS_POWR1220) += powr1220.o > obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > +obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbtsi_temp.c b/drivers/hwmon/sbtsi_temp.c > new file mode 100644 > index 000000000000..e35357c48b8e > --- /dev/null > +++ b/drivers/hwmon/sbtsi_temp.c > @@ -0,0 +1,250 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbtsi_temp.c - hwmon driver for a SBI Temperature Sensor Interface (SB-TSI) > + * compliant AMD SoC temperature device. > + * > + * Copyright (c) 2020, Google Inc. > + * Copyright (c) 2020, Kun Yi > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* > + * SB-TSI registers only support SMBus byte data access. "_INT" registers are > + * the integer part of a temperature value or limit, and "_DEC" registers are > + * corresponding decimal parts. > + */ > +#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 */ > + > +#define SBTSI_CONFIG_READ_ORDER_SHIFT 5 > + > +#define SBTSI_TEMP_MIN 0 > +#define SBTSI_TEMP_MAX 255875 > + > +/* Each client has this additional data */ > +struct sbtsi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* > + * 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" > + * register encodes the base-2 of the integer portion, and the upper 3 bits of > + * the "low byte" encode in base-2 the decimal portion. > + * > + * e.g. INT=0x19, DEC=0x20 represents 25.125 degrees Celsius > + * > + * Therefore temperature in millidegree Celsius = > + * (INT + DEC / 256) * 1000 = (INT * 8 + DEC / 32) * 125 > + */ > +static inline int sbtsi_reg_to_mc(s32 integer, s32 decimal) > +{ > + return ((integer << 3) + (decimal >> 5)) * 125; > +} > + > +/* > + * Inversely, given temperature in millidegree Celsius > + * INT = (TEMP / 125) / 8 > + * DEC = ((TEMP / 125) % 8) * 32 > + * Caller have to make sure temp doesn't exceed 255875, the max valid value. > + */ > +static inline void sbtsi_mc_to_reg(s32 temp, u8 *integer, u8 *decimal) > +{ > + temp /= 125; > + *integer = temp >> 3; > + *decimal = (temp & 0x7) << 5; > +} > + > +static int sbtsi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct sbtsi_data *data = dev_get_drvdata(dev); > + s32 temp_int, temp_dec; > + int err; > + > + switch (attr) { > + case hwmon_temp_input: > + /* > + * ReadOrder bit specifies the reading order of integer and > + * decimal part of CPU temp 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. > + */ > + err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG); > + if (err < 0) > + return err; > + > + mutex_lock(&data->lock); > + if (err & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT)) { > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT); > + } else { > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC); > + } > + mutex_unlock(&data->lock); > + break; > + case hwmon_temp_max: > + mutex_lock(&data->lock); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_DEC); > + mutex_unlock(&data->lock); > + break; > + case hwmon_temp_min: > + mutex_lock(&data->lock); > + temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_INT); > + temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_DEC); > + mutex_unlock(&data->lock); > + break; > + default: > + return -EINVAL; > + } > + > + > + if (temp_int < 0) > + return temp_int; > + if (temp_dec < 0) > + return temp_dec; > + > + *val = sbtsi_reg_to_mc(temp_int, temp_dec); > + > + return 0; > +} > + > +static int sbtsi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct sbtsi_data *data = dev_get_drvdata(dev); > + int reg_int, reg_dec, err; > + u8 temp_int, temp_dec; > + > + switch (attr) { > + case hwmon_temp_max: > + reg_int = SBTSI_REG_TEMP_HIGH_INT; > + reg_dec = SBTSI_REG_TEMP_HIGH_DEC; > + break; > + case hwmon_temp_min: > + reg_int = SBTSI_REG_TEMP_LOW_INT; > + reg_dec = SBTSI_REG_TEMP_LOW_DEC; > + break; > + default: > + return -EINVAL; > + } > + > + val = clamp_val(val, SBTSI_TEMP_MIN, SBTSI_TEMP_MAX); > + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); > + > + mutex_lock(&data->lock); > + err = i2c_smbus_write_byte_data(data->client, reg_int, temp_int); > + if (err) > + goto exit; > + > + err = i2c_smbus_write_byte_data(data->client, reg_dec, temp_dec); > +exit: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static umode_t sbtsi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_temp: > + switch (attr) { > + case hwmon_temp_input: > + return 0444; > + case hwmon_temp_min: > + return 0644; > + case hwmon_temp_max: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbtsi_info[] = { > + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), > + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbtsi_hwmon_ops = { > + .is_visible = sbtsi_is_visible, > + .read = sbtsi_read, > + .write = sbtsi_write, > +}; > + > +static const struct hwmon_chip_info sbtsi_chip_info = { > + .ops = &sbtsi_hwmon_ops, > + .info = sbtsi_info, > +}; > + > +static int sbtsi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbtsi_data *data; > + > + data = devm_kzalloc(dev, sizeof(struct sbtsi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, &sbtsi_chip_info, > + NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct i2c_device_id sbtsi_id[] = { > + {"sbtsi", 0}, > + {} > +}; > +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 = { > + .class = I2C_CLASS_HWMON, > + .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_AUTHOR("Kun Yi "); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); > +MODULE_LICENSE("GPL");