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Message-ID: <20250225-upstream-lt3074-v2-2-18ad10ba542e@analog.com>
Date: Tue, 25 Feb 2025 21:01:14 +0800
From: Cedric Encarnacion <cedricjustine.encarnacion@...log.com>
To: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>, Jean Delvare <jdelvare@...e.com>,
"Guenter Roeck" <linux@...ck-us.net>, Jonathan Corbet <corbet@....net>,
"Delphine CC Chiu" <Delphine_CC_Chiu@...ynn.com>
CC: <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-hwmon@...r.kernel.org>, <linux-doc@...r.kernel.org>,
<linux-i2c@...r.kernel.org>,
Cedric Encarnacion
<cedricjustine.encarnacion@...log.com>
Subject: [PATCH v2 2/2] hwmon: (pmbus/lt3074): add support for lt3074
Add hardware monitoring and regulator support for LT3074. The LT3074 is an
ultrafast, ultralow noise 3A, 5.5V dropout linear regulator. The PMBus
serial interface allows telemetry for input/output voltage, bias voltage,
output current, and die temperature.
Signed-off-by: Cedric Encarnacion <cedricjustine.encarnacion@...log.com>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/lt3074.rst | 72 ++++++++++++++++++++++++
MAINTAINERS | 2 +
drivers/hwmon/pmbus/Kconfig | 18 ++++++
drivers/hwmon/pmbus/Makefile | 1 +
drivers/hwmon/pmbus/lt3074.c | 122 +++++++++++++++++++++++++++++++++++++++++
6 files changed, 216 insertions(+)
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 874f8fd2632520d3be489154ddd0eb7ca24fc405..54b14f571db4d3b3e0b74a12b41cf8cf0d6fe8a7 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -122,6 +122,7 @@ Hardware Monitoring Kernel Drivers
lm95234
lm95245
lochnagar
+ lt3074
lt7182s
ltc2992
ltc2945
diff --git a/Documentation/hwmon/lt3074.rst b/Documentation/hwmon/lt3074.rst
new file mode 100644
index 0000000000000000000000000000000000000000..234f369153cf1374b8c7eaa2ed93358ac141fdf9
--- /dev/null
+++ b/Documentation/hwmon/lt3074.rst
@@ -0,0 +1,72 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver lt3074
+====================
+
+Supported chips:
+
+ * Analog Devices LT3074
+
+ Prefix: 'lt3074'
+
+ Addresses scanned: -
+
+ Datasheet: https://www.analog.com/en/products/lt3074.html
+
+Authors: Cedric Encarnacion <cedricjustine.encarnacion@...log.com>
+
+
+Description
+-----------
+
+This driver supports hardware monitoring for Analog Devices LT3074 Linear
+Regulator with PMBus interface.
+
+The LT3074 is a low voltage, ultra-low noise and ultra-fast transient
+response linear regulator with PMBus serial interface. PMBus telemetry
+feature provides information regarding the output voltage and current,
+input voltage, bias voltage and die temperature.
+
+The driver is a client driver to the core PMBus driver. Please see
+Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate
+the devices explicitly. Please see Documentation/i2c/instantiating-devices.rst
+for details.
+
+Platform data support
+---------------------
+
+The driver supports standard PMBus driver platform data.
+
+Sysfs entries
+-------------
+
+======================= =======================================================
+in1_label "vin"
+in1_input Measured input voltage
+in1_max Input overvoltage warning limit
+in1_max_alarm Input overvoltage warning status
+in1_min Input undervoltage warning limit
+in1_min_alarm Input undervoltage warning status
+in2_label "vmon"
+in2_input Measured bias voltage
+in2_max Bias overvoltage warning limit
+in2_min Bias undervoltage warning limit
+in3_label "vout1"
+in3_input Measured output voltage
+in3_max Output overvoltage warning limit
+in3_max_alarm Output overvoltage warning status
+in3_min Output undervoltage warning limit
+in3_min_alarm Output undervoltage warning status
+curr1_label "iout1"
+curr1_input Measured output current.
+curr1_crit Output overcurrent fault limit
+curr1_crit_alarm Output overcurrent fault status
+temp1_input Measured temperature
+temp1_max Maximum temperature limit
+temp1_max_alarm Overtemperature warning status
+======================= =======================================================
diff --git a/MAINTAINERS b/MAINTAINERS
index 4a59ee6a03919af6a48717a0ddddabc7241a9e63..be9372cf020c246586646ad240a0c0c7880800f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13693,6 +13693,8 @@ L: linux-hwmon@...r.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/hwmon/pmbus/adi,lt3074.yaml
+F: Documentation/hwmon/lt3074.rst
+F: drivers/hwmon/pmbus/lt3074.c
LTC1660 DAC DRIVER
M: Marcus Folkesson <marcus.folkesson@...il.com>
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 675b0d4703d87c9d5654489d0d770661ff0dba11..3edad8d7476cf78f4c2dfc94294013b33f2d8cae 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -209,6 +209,24 @@ config SENSORS_LM25066_REGULATOR
If you say yes here you get regulator support for National
Semiconductor LM25066, LM5064, and LM5066.
+config SENSORS_LT3074
+ tristate "Analog Devices LT3074"
+ help
+ If you say yes here you get hardware monitoring support for Analog
+ Devices LT3074.
+
+ This driver can also be built as a module. If so, the module will
+ be called lt3074.
+
+config SENSORS_LT3074_REGULATOR
+ tristate "Regulator support for LT3074"
+ depends on SENSORS_LT3074 && REGULATOR
+ help
+ If you say yes here you get regulator support for Analog Devices
+ LT3074. The LT3074 is a low voltage, ultralow noise, high PSRR,
+ dropout linear regulator. The device supplies up to 3A with a
+ typical dropout voltage of 45mV.
+
config SENSORS_LT7182S
tristate "Analog Devices LT7182S"
help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index c7eb7739b7f861c5c105582b57ad16937649d4cf..5ef388c105811e73d5ea943648fb2f7a7ca59010 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_SENSORS_IR38064) += ir38064.o
obj-$(CONFIG_SENSORS_IRPS5401) += irps5401.o
obj-$(CONFIG_SENSORS_ISL68137) += isl68137.o
obj-$(CONFIG_SENSORS_LM25066) += lm25066.o
+obj-$(CONFIG_SENSORS_LT3074) += lt3074.o
obj-$(CONFIG_SENSORS_LT7182S) += lt7182s.o
obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o
obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o
diff --git a/drivers/hwmon/pmbus/lt3074.c b/drivers/hwmon/pmbus/lt3074.c
new file mode 100644
index 0000000000000000000000000000000000000000..a84bc5bddee7c4ae646b4fc7c5a57ed1eb233ab8
--- /dev/null
+++ b/drivers/hwmon/pmbus/lt3074.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware monitoring driver for Analog Devices LT3074
+ *
+ * Copyright (C) 2025 Analog Devices, Inc.
+ */
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+
+#include "pmbus.h"
+
+#define LT3074_MFR_READ_VBIAS 0xc6
+#define LT3074_MFR_BIAS_OV_WARN_LIMIT 0xc7
+#define LT3074_MFR_BIAS_UV_WARN_LIMIT 0xc8
+#define LT3074_MFR_SPECIAL_ID 0xe7
+
+#define LT3074_SPECIAL_ID_VALUE 0x1c1d
+
+static const struct regulator_desc __maybe_unused lt3074_reg_desc[] = {
+ PMBUS_REGULATOR_ONE("vout"),
+};
+
+static int lt3074_read_word_data(struct i2c_client *client, int page,
+ int phase, int reg)
+{
+ switch (reg) {
+ case PMBUS_VIRT_READ_VMON:
+ return pmbus_read_word_data(client, page, phase,
+ LT3074_MFR_READ_VBIAS);
+ case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
+ return pmbus_read_word_data(client, page, phase,
+ LT3074_MFR_BIAS_UV_WARN_LIMIT);
+ case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
+ return pmbus_read_word_data(client, page, phase,
+ LT3074_MFR_BIAS_OV_WARN_LIMIT);
+ default:
+ return -ENODATA;
+ }
+}
+
+static int lt3074_write_word_data(struct i2c_client *client, int page,
+ int reg, u16 word)
+{
+ switch (reg) {
+ case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
+ return pmbus_write_word_data(client, 0,
+ LT3074_MFR_BIAS_UV_WARN_LIMIT,
+ word);
+ case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
+ return pmbus_write_word_data(client, 0,
+ LT3074_MFR_BIAS_OV_WARN_LIMIT,
+ word);
+ default:
+ return -ENODATA;
+ }
+}
+
+static struct pmbus_driver_info lt3074_info = {
+ .pages = 1,
+ .format[PSC_VOLTAGE_IN] = linear,
+ .format[PSC_VOLTAGE_OUT] = linear,
+ .format[PSC_CURRENT_OUT] = linear,
+ .format[PSC_TEMPERATURE] = linear,
+ .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
+ PMBUS_HAVE_TEMP | PMBUS_HAVE_VMON |
+ PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+ .read_word_data = lt3074_read_word_data,
+ .write_word_data = lt3074_write_word_data,
+#if IS_ENABLED(CONFIG_SENSORS_LT3074_REGULATOR)
+ .num_regulators = 1,
+ .reg_desc = lt3074_reg_desc,
+#endif
+};
+
+static int lt3074_probe(struct i2c_client *client)
+{
+ int ret;
+ struct device *dev = &client->dev;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_WORD_DATA))
+ return -ENODEV;
+
+ ret = i2c_smbus_read_word_data(client, LT3074_MFR_SPECIAL_ID);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to read ID\n");
+
+ if (ret != LT3074_SPECIAL_ID_VALUE)
+ return dev_err_probe(dev, -ENODEV, "ID mismatch\n");
+
+ return pmbus_do_probe(client, <3074_info);
+}
+
+static const struct i2c_device_id lt3074_id[] = {
+ { "lt3074", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, lt3074_id);
+
+static const struct of_device_id __maybe_unused lt3074_of_match[] = {
+ { .compatible = "adi,lt3074" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, lt3074_of_match);
+
+static struct i2c_driver lt3074_driver = {
+ .driver = {
+ .name = "lt3074",
+ .of_match_table = of_match_ptr(lt3074_of_match),
+ },
+ .probe = lt3074_probe,
+ .id_table = lt3074_id,
+};
+module_i2c_driver(lt3074_driver);
+
+MODULE_AUTHOR("Cedric Encarnacion <cedricjustine.encarnacion@...log.com>");
+MODULE_DESCRIPTION("PMBus driver for Analog Devices LT3074");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");
--
2.39.5
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