* [PATCH linux hwmon-next v4 0/3] SB-TSI hwmon driver v4
@ 2020-12-02 16:55 Kun Yi
2020-12-02 16:55 ` [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Kun Yi
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Kun Yi @ 2020-12-02 16:55 UTC (permalink / raw)
To: jdelvare, linux, robh+dt, mark.rutland, supreeth.venkatesh
Cc: linux-hwmon, devicetree, openbmc, linux-kernel
v4: addressed comments in v3; converted DT binding to required schema
v3: addressed comment in v2 and improved documentation
v2: rewrote using devm_hwmon_device_register_with_info() API and addressed
comments received in v1
v1: first version
Kun Yi (3):
hwmon: (sbtsi) Add basic support for SB-TSI sensors
hwmon: (sbtsi) Add documentation
dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings
.../devicetree/bindings/hwmon/amd,sbtsi.yaml | 54 ++++
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/sbtsi_temp.rst | 40 +++
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/sbtsi_temp.c | 265 ++++++++++++++++++
6 files changed, 371 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml
create mode 100644 Documentation/hwmon/sbtsi_temp.rst
create mode 100644 drivers/hwmon/sbtsi_temp.c
--
2.29.2.454.gaff20da3a2-goog
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors 2020-12-02 16:55 [PATCH linux hwmon-next v4 0/3] SB-TSI hwmon driver v4 Kun Yi @ 2020-12-02 16:55 ` Kun Yi 2020-12-09 20:13 ` Supreeth Venkatesh [not found] ` <20201203013748.GA228752@roeck-us.net> 2020-12-02 16:56 ` [PATCH linux hwmon-next v4 2/3] hwmon: (sbtsi) Add documentation Kun Yi 2020-12-02 16:56 ` [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings Kun Yi 2 siblings, 2 replies; 8+ messages in thread From: Kun Yi @ 2020-12-02 16:55 UTC (permalink / raw) To: jdelvare, linux, robh+dt, mark.rutland, supreeth.venkatesh Cc: linux-hwmon, devicetree, openbmc, linux-kernel 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 <kunyi@google.com> --- drivers/hwmon/Kconfig | 10 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/sbtsi_temp.c | 265 +++++++++++++++++++++++++++++++++++++ 3 files changed, 276 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..6b0a7b9df1f3 --- /dev/null +++ b/drivers/hwmon/sbtsi_temp.c @@ -0,0 +1,265 @@ +// 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 <kunyi@google.com> + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/hwmon.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <linux/of.h> + +/* + * 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, reg_int, reg_dec; + bool reading_input; + + if (type != hwmon_temp) + return -EINVAL; + + reading_input = false; + switch (attr) { + case hwmon_temp_input: + reading_input = true; + /* + * 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: + 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; + } + + if (!reading_input) { + temp_int = i2c_smbus_read_byte_data(data->client, reg_int); + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec); + } + + 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; + + if (type != hwmon_temp) + return -EINVAL; + + 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); + mutex_lock(&data->lock); + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); + 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 <kunyi@google.com>"); +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); +MODULE_LICENSE("GPL"); -- 2.29.2.454.gaff20da3a2-goog ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors 2020-12-02 16:55 ` [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Kun Yi @ 2020-12-09 20:13 ` Supreeth Venkatesh [not found] ` <20201203013748.GA228752@roeck-us.net> 1 sibling, 0 replies; 8+ messages in thread From: Supreeth Venkatesh @ 2020-12-09 20:13 UTC (permalink / raw) To: Kun Yi, jdelvare, linux, robh+dt, mark.rutland Cc: linux-hwmon, devicetree, openbmc, linux-kernel On 12/2/20 10:55 AM, Kun Yi wrote: > [CAUTION: External Email] > > 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://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.amd.com%2Fsystem%2Ffiles%2FTechDocs%2F56255_OSRR.pdf&data=04%7C01%7Csupreeth.venkatesh%40amd.com%7C412ca045665445483a0a08d896e33084%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C1%7C637425250268541698%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=Xir5Jg%2FgHz8isnXNkmZMTRjg%2FOht%2FSDR4gajR5wVgSU%3D&reserved=0 > > Test status: tested reading temp1_input, and reading/writing > temp1_max/min. > > Signed-off-by: Kun Yi <kunyi@google.com> Series Acked-by: Supreeth Venkatesh <supreeth.venkatesh@amd.com> > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbtsi_temp.c | 265 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 276 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..6b0a7b9df1f3 > --- /dev/null > +++ b/drivers/hwmon/sbtsi_temp.c > @@ -0,0 +1,265 @@ > +// 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 <kunyi@google.com> > + */ > + > +#include <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/hwmon.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of_device.h> > +#include <linux/of.h> > + > +/* > + * 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, reg_int, reg_dec; > + bool reading_input; > + > + if (type != hwmon_temp) > + return -EINVAL; > + > + reading_input = false; > + switch (attr) { > + case hwmon_temp_input: > + reading_input = true; > + /* > + * 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: > + 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; > + } > + > + if (!reading_input) { > + temp_int = i2c_smbus_read_byte_data(data->client, reg_int); > + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec); > + } > + > + 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; > + > + if (type != hwmon_temp) > + return -EINVAL; > + > + 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); > + mutex_lock(&data->lock); > + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); > + 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 <kunyi@google.com>"); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); > +MODULE_LICENSE("GPL"); > -- > 2.29.2.454.gaff20da3a2-goog > ^ permalink raw reply [flat|nested] 8+ messages in thread
[parent not found: <20201203013748.GA228752@roeck-us.net>]
* RE: [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors [not found] ` <20201203013748.GA228752@roeck-us.net> @ 2020-12-03 18:06 ` Chatradhi, Naveen Krishna 2020-12-11 21:57 ` Kun Yi 1 sibling, 0 replies; 8+ messages in thread From: Chatradhi, Naveen Krishna @ 2020-12-03 18:06 UTC (permalink / raw) To: Guenter Roeck, Kun Yi Cc: mark.rutland, linux-hwmon, jdelvare, devicetree, openbmc, linux-kernel, robh+dt, Venkatesh, Supreeth [AMD Official Use Only - Approved for External Use] Hi Kun Yi, > Test status: tested reading temp1_input, and reading/writing > temp1_max/min. Tested the above at our end from an arm based BMC connected to the 2P Rome machine, it works fine. Regards, Naveenk -----Original Message----- From: Guenter Roeck <linux@roeck-us.net> Sent: Thursday, December 3, 2020 7:08 AM To: Kun Yi <kunyi@google.com> Cc: jdelvare@suse.com; robh+dt@kernel.org; mark.rutland@arm.com; Venkatesh, Supreeth <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 v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors [CAUTION: External Email] On Wed, Dec 02, 2020 at 08:55:59AM -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://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww. > amd.com%2Fsystem%2Ffiles%2FTechDocs%2F56255_OSRR.pdf&data=04%7C01% > 7CNaveenKrishna.Chatradhi%40amd.com%7C1a8cb0ebe4bb43bc759808d8972c562f > %7C3dd8961fe4884e608e11a82d994e183d%7C0%7C1%7C637425563976853035%7CUnk > nown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWw > iLCJXVCI6Mn0%3D%7C1000&sdata=oH5YmE000EUVGVxruzI%2FBRnWOKptlG%2Bpf > yKferIwYME%3D&reserved=0 > > Test status: tested reading temp1_input, and reading/writing > temp1_max/min. > > Signed-off-by: Kun Yi <kunyi@google.com> > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbtsi_temp.c | 265 > +++++++++++++++++++++++++++++++++++++ > 3 files changed, 276 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..6b0a7b9df1f3 > --- /dev/null > +++ b/drivers/hwmon/sbtsi_temp.c > @@ -0,0 +1,265 @@ > +// 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 <kunyi@google.com> */ > + > +#include <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/hwmon.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of_device.h> > +#include <linux/of.h> > + > +/* > + * 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, reg_int, reg_dec; > + bool reading_input; > + > + if (type != hwmon_temp) > + return -EINVAL; Unnecessary check. > + > + reading_input = false; > + switch (attr) { > + case hwmon_temp_input: > + reading_input = true; > + /* > + * 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: > + 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; > + } > + > + if (!reading_input) { > + temp_int = i2c_smbus_read_byte_data(data->client, reg_int); > + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec); > + } This adds unnecessary complexity. I would suggest to move the calls to the case statements and drop reading_input as well as reg_int, reg_dec. Also, I just realized that the mutex is needed here as well, since the values might be written while being read, which could result in inconsistent read values. Example: Limit is changed from 100 to 99.75. Since the integer value is written first, it is possible that 99.0 is returned. > + > + 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; > + > + if (type != hwmon_temp) > + return -EINVAL; This check is really unnecessary. > + > + 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); > + mutex_lock(&data->lock); > + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); > + 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, Line length limit is now 100 columns, so the above line split is unnecessary. > + &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 <kunyi@google.com>"); MODULE_DESCRIPTION("Hwmon > +driver for AMD SB-TSI emulated sensor"); MODULE_LICENSE("GPL"); > -- > 2.29.2.454.gaff20da3a2-goog > ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors [not found] ` <20201203013748.GA228752@roeck-us.net> 2020-12-03 18:06 ` Chatradhi, Naveen Krishna @ 2020-12-11 21:57 ` Kun Yi 1 sibling, 0 replies; 8+ messages in thread From: Kun Yi @ 2020-12-11 21:57 UTC (permalink / raw) To: Guenter Roeck Cc: mark.rutland, linux-hwmon, jdelvare, devicetree, OpenBMC Maillist, linux-kernel, robh+dt, Venkatesh, Supreeth Thanks Guenter for reviewing! On Wed, Dec 2, 2020 at 5:37 PM Guenter Roeck <linux@roeck-us.net> wrote: > > On Wed, Dec 02, 2020 at 08:55:59AM -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 <kunyi@google.com> > > --- > > drivers/hwmon/Kconfig | 10 ++ > > drivers/hwmon/Makefile | 1 + > > drivers/hwmon/sbtsi_temp.c | 265 +++++++++++++++++++++++++++++++++++++ > > 3 files changed, 276 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..6b0a7b9df1f3 > > --- /dev/null > > +++ b/drivers/hwmon/sbtsi_temp.c > > @@ -0,0 +1,265 @@ > > +// 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 <kunyi@google.com> > > + */ > > + > > +#include <linux/err.h> > > +#include <linux/i2c.h> > > +#include <linux/init.h> > > +#include <linux/hwmon.h> > > +#include <linux/module.h> > > +#include <linux/mutex.h> > > +#include <linux/of_device.h> > > +#include <linux/of.h> > > + > > +/* > > + * 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, reg_int, reg_dec; > > + bool reading_input; > > + > > + if (type != hwmon_temp) > > + return -EINVAL; > > Unnecessary check. Removed. > > > + > > + reading_input = false; > > + switch (attr) { > > + case hwmon_temp_input: > > + reading_input = true; > > + /* > > + * 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: > > + 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; > > + } > > + > > + if (!reading_input) { > > + temp_int = i2c_smbus_read_byte_data(data->client, reg_int); > > + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec); > > + } > > This adds unnecessary complexity. I would suggest to move the calls > to the case statements and drop reading_input as well as reg_int, > reg_dec. Done. > > Also, I just realized that the mutex is needed here as well, since > the values might be written while being read, which could result in > inconsistent read values. Example: Limit is changed from 100 to 99.75. > Since the integer value is written first, it is possible that 99.0 > is returned. That's a good catch. Modified. > > > + > > + 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; > > + > > + if (type != hwmon_temp) > > + return -EINVAL; > > This check is really unnecessary. Removed. > > > + > > + 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); > > + mutex_lock(&data->lock); > > + sbtsi_mc_to_reg(val, &temp_int, &temp_dec); > > + 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, > > Line length limit is now 100 columns, so the above line split is unnecessary. Wow I didn't know.. Thanks! Adjusted a couple other lines based on the 100 cols. > > > + &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 <kunyi@google.com>"); > > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor"); > > +MODULE_LICENSE("GPL"); > > -- > > 2.29.2.454.gaff20da3a2-goog > > -- Regards, Kun ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH linux hwmon-next v4 2/3] hwmon: (sbtsi) Add documentation 2020-12-02 16:55 [PATCH linux hwmon-next v4 0/3] SB-TSI hwmon driver v4 Kun Yi 2020-12-02 16:55 ` [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Kun Yi @ 2020-12-02 16:56 ` Kun Yi 2020-12-02 16:56 ` [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings Kun Yi 2 siblings, 0 replies; 8+ messages in thread From: Kun Yi @ 2020-12-02 16:56 UTC (permalink / raw) To: jdelvare, linux, robh+dt, mark.rutland, supreeth.venkatesh Cc: linux-hwmon, devicetree, openbmc, linux-kernel Document the SB-TSI sensor interface driver. Signed-off-by: Kun Yi <kunyi@google.com> --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/sbtsi_temp.rst | 40 ++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) create mode 100644 Documentation/hwmon/sbtsi_temp.rst diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index fd6fae46b99c..509fb3bcafb2 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -151,6 +151,7 @@ Hardware Monitoring Kernel Drivers pxe1610 pwm-fan raspberrypi-hwmon + sbtsi_temp sch5627 sch5636 scpi-hwmon diff --git a/Documentation/hwmon/sbtsi_temp.rst b/Documentation/hwmon/sbtsi_temp.rst new file mode 100644 index 000000000000..9f0f197c8aa2 --- /dev/null +++ b/Documentation/hwmon/sbtsi_temp.rst @@ -0,0 +1,40 @@ +Kernel driver sbtsi_temp +================== + +Supported hardware: + + * Sideband interface (SBI) Temperature Sensor Interface (SB-TSI) + compliant AMD SoC temperature device. + + Prefix: 'sbtsi_temp' + + Addresses scanned: This driver doesn't support address scanning. + + 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 SoC register reference: 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. + + Datasheet: The SB-TSI interface and protocol is available as part of + the open source SoC register reference at: + + https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf + + The Advanced Platform Management Link (APML) Specification is + available at: + + http://developer.amd.com/wordpress/media/2012/10/41918.pdf + +Author: Kun Yi <kunyi@google.com> + +Description +----------- + +The SBI temperature sensor interface (SB-TSI) is an emulation of the software +and physical interface of a typical 8-pin remote temperature sensor (RTS) on +AMD SoCs. It implements one temperature sensor with readings and limit +registers encode the temperature in increments of 0.125 from 0 to 255.875. +Limits can be set through the writable thresholds, and if reached will trigger +corresponding alert signals. -- 2.29.2.454.gaff20da3a2-goog ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings 2020-12-02 16:55 [PATCH linux hwmon-next v4 0/3] SB-TSI hwmon driver v4 Kun Yi 2020-12-02 16:55 ` [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Kun Yi 2020-12-02 16:56 ` [PATCH linux hwmon-next v4 2/3] hwmon: (sbtsi) Add documentation Kun Yi @ 2020-12-02 16:56 ` Kun Yi 2020-12-09 20:06 ` Rob Herring 2 siblings, 1 reply; 8+ messages in thread From: Kun Yi @ 2020-12-02 16:56 UTC (permalink / raw) To: jdelvare, linux, robh+dt, mark.rutland, supreeth.venkatesh Cc: linux-hwmon, devicetree, openbmc, linux-kernel Document device tree bindings for AMD SB-TSI emulated temperature sensor. Signed-off-by: Kun Yi <kunyi@google.com> --- .../devicetree/bindings/hwmon/amd,sbtsi.yaml | 54 +++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml diff --git a/Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml b/Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml new file mode 100644 index 000000000000..446b09f1ce94 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml @@ -0,0 +1,54 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/hwmon/amd,sbtsi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: > + Sideband interface Temperature Sensor Interface (SB-TSI) compliant + AMD SoC temperature device + +maintainers: + - Kun Yi <kunyi@google.com> + - Supreeth Venkatesh <supreeth.venkatesh@amd.com> + +description: | + 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. The emulated thermal sensor can report temperatures in increments + of 0.125 degrees, ranging from 0 to 255.875. + +properties: + compatible: + enum: + - amd,sbtsi + + reg: + maxItems: 1 + description: | + I2C bus address of the device as specified in Section 6.3.1 of the + SoC register reference. 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. + \[open source SoC register reference\] + https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + i2c0 { + #address-cells = <1>; + #size-cells = <0>; + + sbtsi@4c { + compatible = "amd,sbtsi"; + reg = <0x4c>; + }; + }; +... -- 2.29.2.454.gaff20da3a2-goog ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings 2020-12-02 16:56 ` [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings Kun Yi @ 2020-12-09 20:06 ` Rob Herring 0 siblings, 0 replies; 8+ messages in thread From: Rob Herring @ 2020-12-09 20:06 UTC (permalink / raw) To: Kun Yi Cc: mark.rutland, devicetree, jdelvare, openbmc, linux-kernel, robh+dt, supreeth.venkatesh, linux-hwmon, linux On Wed, 02 Dec 2020 08:56:01 -0800, Kun Yi wrote: > Document device tree bindings for AMD SB-TSI emulated temperature > sensor. > > Signed-off-by: Kun Yi <kunyi@google.com> > --- > .../devicetree/bindings/hwmon/amd,sbtsi.yaml | 54 +++++++++++++++++++ > 1 file changed, 54 insertions(+) > create mode 100644 Documentation/devicetree/bindings/hwmon/amd,sbtsi.yaml > Reviewed-by: Rob Herring <robh@kernel.org> ^ permalink raw reply [flat|nested] 8+ messages in thread
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Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2020-12-02 16:55 [PATCH linux hwmon-next v4 0/3] SB-TSI hwmon driver v4 Kun Yi
2020-12-02 16:55 ` [PATCH linux hwmon-next v4 1/3] hwmon: (sbtsi) Add basic support for SB-TSI sensors Kun Yi
2020-12-09 20:13 ` Supreeth Venkatesh
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2020-12-03 18:06 ` Chatradhi, Naveen Krishna
2020-12-11 21:57 ` Kun Yi
2020-12-02 16:56 ` [PATCH linux hwmon-next v4 2/3] hwmon: (sbtsi) Add documentation Kun Yi
2020-12-02 16:56 ` [PATCH linux hwmon-next v4 3/3] dt-bindings: (hwmon/sbtsi_tmep) Add SB-TSI hwmon driver bindings Kun Yi
2020-12-09 20:06 ` Rob Herring
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