This patchset adds hwmon support for AMD SoC SB-TSI emulated temperature
sensor and related 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/sbtsi_temp.txt | 14 +
Documentation/hwmon/sbtsi_temp.rst | 40 +++
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/sbtsi_temp.c | 261 ++++++++++++++++++
5 files changed, 326 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
create mode 100644 Documentation/hwmon/sbtsi_temp.rst
create mode 100644 drivers/hwmon/sbtsi_temp.c
--
2.25.1.696.g5e7596f4ac-goog
Document the SB-TSI sensor interface driver.
Signed-off-by: Kun Yi <[email protected]>
Change-Id: I4b086a124d1d94a516386b0d2ff1cd7180b1dac1
---
Documentation/hwmon/sbtsi_temp.rst | 40 ++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644 Documentation/hwmon/sbtsi_temp.rst
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 <[email protected]>
+
+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.
--
2.25.1.696.g5e7596f4ac-goog
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 <[email protected]>
Change-Id: I85ec65a57e8d73d7343aa9e250860ec85bfa79e5
---
drivers/hwmon/Kconfig | 10 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/sbtsi_temp.c | 261 +++++++++++++++++++++++++++++++++++++
3 files changed, 272 insertions(+)
create mode 100644 drivers/hwmon/sbtsi_temp.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 05a30832c6ba..9585dcd01d1b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1412,6 +1412,16 @@ config SENSORS_RASPBERRYPI_HWMON
This driver can also be built as a module. If so, the module
will be called raspberrypi-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 b0b9c8e57176..cd109f003ce4 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -152,6 +152,7 @@ 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..cc452cb29c2c
--- /dev/null
+++ b/drivers/hwmon/sbtsi_temp.c
@@ -0,0 +1,261 @@
+// 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 <[email protected]>
+ */
+
+#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_REG_REV 0xFF /* RO */
+
+#define SBTSI_CONFIG_READ_ORDER_SHIFT 5
+
+#define SBTSI_TEMP_MIN 0
+#define SBTSI_TEMP_MAX 255875
+#define SBTSI_REV_MAX_VALID_ID 4
+
+/* 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;
+ u8 read_order;
+
+ if (type != hwmon_temp)
+ return -EINVAL;
+
+ read_order = 0;
+ 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;
+
+ read_order = (u8)err & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT);
+ reg_int = SBTSI_REG_TEMP_INT;
+ reg_dec = SBTSI_REG_TEMP_DEC;
+ 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 (read_order == 0) {
+ temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
+ temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
+ } else {
+ temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
+ temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
+ }
+
+ 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);
+
+ dev_set_drvdata(dev, data);
+
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor");
+MODULE_LICENSE("GPL");
--
2.25.1.696.g5e7596f4ac-goog
Document device tree bindings for AMD SB-TSI emulated temperature
sensor.
Signed-off-by: Kun Yi <[email protected]>
Change-Id: Ife3285afa4cf8d410cb7bee1eb930dc0717084f9
---
.../devicetree/bindings/hwmon/sbtsi_temp.txt | 14 ++++++++++++++
1 file changed, 14 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
diff --git a/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt b/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
new file mode 100644
index 000000000000..4020f075699e
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
@@ -0,0 +1,14 @@
+*AMD SoC SB-TSI hwmon driver.
+
+Required properties:
+- compatible: manufacturer and chip name, should be
+ "amd,sbtsi",
+
+- reg: I2C bus address of the device
+
+Example:
+
+sbtsi@4c {
+ compatible = "amd,sbtsi";
+ reg = <0x4c>;
+};
--
2.25.1.696.g5e7596f4ac-goog
On Mon, Mar 23, 2020 at 04:33:53PM -0700, Kun Yi wrote:
> Document the SB-TSI sensor interface driver.
>
> Signed-off-by: Kun Yi <[email protected]>
> Change-Id: I4b086a124d1d94a516386b0d2ff1cd7180b1dac1
> ---
> Documentation/hwmon/sbtsi_temp.rst | 40 ++++++++++++++++++++++++++++++
The new file also needs to be added to Documentation/hwmon/index.rst.
Guenter
On Mon, Mar 23, 2020 at 04:33:52PM -0700, 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 <[email protected]>
> Change-Id: I85ec65a57e8d73d7343aa9e250860ec85bfa79e5
> ---
> drivers/hwmon/Kconfig | 10 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/sbtsi_temp.c | 261 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 272 insertions(+)
> create mode 100644 drivers/hwmon/sbtsi_temp.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 05a30832c6ba..9585dcd01d1b 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1412,6 +1412,16 @@ config SENSORS_RASPBERRYPI_HWMON
> This driver can also be built as a module. If so, the module
> will be called raspberrypi-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 b0b9c8e57176..cd109f003ce4 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -152,6 +152,7 @@ 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..cc452cb29c2c
> --- /dev/null
> +++ b/drivers/hwmon/sbtsi_temp.c
> @@ -0,0 +1,261 @@
> +// 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 <[email protected]>
> + */
> +
> +#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_REG_REV 0xFF /* RO */
> +
> +#define SBTSI_CONFIG_READ_ORDER_SHIFT 5
> +
> +#define SBTSI_TEMP_MIN 0
> +#define SBTSI_TEMP_MAX 255875
> +#define SBTSI_REV_MAX_VALID_ID 4
> +
> +/* 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;
> + u8 read_order;
> +
> + if (type != hwmon_temp)
> + return -EINVAL;
> +
> + read_order = 0;
> + 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;
> +
> + read_order = (u8)err & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT);
> + reg_int = SBTSI_REG_TEMP_INT;
> + reg_dec = SBTSI_REG_TEMP_DEC;
> + 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 (read_order == 0) {
> + temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
> + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
> + } else {
> + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
> + temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
> + }
> +
> + 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);
> +
> + dev_set_drvdata(dev, data);
> +
This is not needed.
Guenter
> + 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 <[email protected]>");
> +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor");
> +MODULE_LICENSE("GPL");
On Mon, Mar 23, 2020 at 04:33:54PM -0700, Kun Yi wrote:
> Document device tree bindings for AMD SB-TSI emulated temperature
> sensor.
>
> Signed-off-by: Kun Yi <[email protected]>
> Change-Id: Ife3285afa4cf8d410cb7bee1eb930dc0717084f9
> ---
> .../devicetree/bindings/hwmon/sbtsi_temp.txt | 14 ++++++++++++++
Convert to DT schema format and use the compatible string as the
filename.
> 1 file changed, 14 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
>
> diff --git a/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt b/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
> new file mode 100644
> index 000000000000..4020f075699e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/sbtsi_temp.txt
> @@ -0,0 +1,14 @@
> +*AMD SoC SB-TSI hwmon driver.
Bindings are for hardware, not drivers.
Please give a better explanation of what this h/w.
> +
> +Required properties:
> +- compatible: manufacturer and chip name, should be
> + "amd,sbtsi",
> +
> +- reg: I2C bus address of the device
> +
> +Example:
> +
> +sbtsi@4c {
> + compatible = "amd,sbtsi";
> + reg = <0x4c>;
> +};
> --
> 2.25.1.696.g5e7596f4ac-goog
>
On Tue, Mar 31, 2020 at 8:46 AM Guenter Roeck <[email protected]> wrote:
>
> On Mon, Mar 23, 2020 at 04:33:52PM -0700, 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 <[email protected]>
> > Change-Id: I85ec65a57e8d73d7343aa9e250860ec85bfa79e5
> > ---
> > drivers/hwmon/Kconfig | 10 ++
> > drivers/hwmon/Makefile | 1 +
> > drivers/hwmon/sbtsi_temp.c | 261 +++++++++++++++++++++++++++++++++++++
> > 3 files changed, 272 insertions(+)
> > create mode 100644 drivers/hwmon/sbtsi_temp.c
> >
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index 05a30832c6ba..9585dcd01d1b 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -1412,6 +1412,16 @@ config SENSORS_RASPBERRYPI_HWMON
> > This driver can also be built as a module. If so, the module
> > will be called raspberrypi-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 b0b9c8e57176..cd109f003ce4 100644
> > --- a/drivers/hwmon/Makefile
> > +++ b/drivers/hwmon/Makefile
> > @@ -152,6 +152,7 @@ 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..cc452cb29c2c
> > --- /dev/null
> > +++ b/drivers/hwmon/sbtsi_temp.c
> > @@ -0,0 +1,261 @@
> > +// 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 <[email protected]>
> > + */
> > +
> > +#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_REG_REV 0xFF /* RO */
> > +
> > +#define SBTSI_CONFIG_READ_ORDER_SHIFT 5
> > +
> > +#define SBTSI_TEMP_MIN 0
> > +#define SBTSI_TEMP_MAX 255875
> > +#define SBTSI_REV_MAX_VALID_ID 4
> > +
> > +/* 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;
> > + u8 read_order;
> > +
> > + if (type != hwmon_temp)
> > + return -EINVAL;
> > +
> > + read_order = 0;
> > + 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;
> > +
> > + read_order = (u8)err & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT);
> > + reg_int = SBTSI_REG_TEMP_INT;
> > + reg_dec = SBTSI_REG_TEMP_DEC;
> > + 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 (read_order == 0) {
> > + temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
> > + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
> > + } else {
> > + temp_dec = i2c_smbus_read_byte_data(data->client, reg_dec);
> > + temp_int = i2c_smbus_read_byte_data(data->client, reg_int);
> > + }
> > +
> > + 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);
> > +
> > + dev_set_drvdata(dev, data);
> > +
>
> This is not needed.
Thanks. Removed in v3.
>
> Guenter
>
> > + 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 <[email protected]>");
> > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-TSI emulated sensor");
> > +MODULE_LICENSE("GPL");
--
Regards,
Kun