hwmon: pmbus: add driver for ltp8800-1a, ltp8800-4a, and ltp8800-2

LTP8800-1A 150A DC/DC µModule Regulator with PMBus Interface
LTP8800-4A 200A DC/DC µModule Regulator with PMBus Interface
LTP8800-2 54V, 135A DC/DC μModule Regulator with PMBus Interface

Signed-off-by: Cedric Encarnacion <cedricjustine.encarnacion@analog.com>

Author: cencarna

Documentation/hwmon/index.rst

@@ -122,6 +122,7 @@ Hardware Monitoring Kernel Drivers
    ltc4245
    ltc4260
    ltc4261
+   ltp8800
    max127
    max15301
    max16064

Documentation/hwmon/ltp8800.rst

@@ -0,0 +1,103 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver ltp8800
+=====================
+
+Supported chips:
+
+	* Analog Devices LTP8800-1A
+
+		Prefix: 'ltp8800-1a'
+
+		Addresses scanned: I2C 0x40 - 0x4F
+
+		Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltp8800-1a.pdf
+
+	* Analog Devices LTP8800-4A
+
+		Prefix: 'ltp8800-4a'
+
+		Addresses scanned: I2C 0x40 - 0x4F
+
+		Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltp8800-4a.pdf
+
+	* Analog Devices LTP8800-2
+
+		Prefix: 'ltp8800-2'
+
+		Addresses scanned: I2C 0x40 - 0x4F
+
+		Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltp8800-2.pdf
+
+Authors:
+		- Cedric Encarnacion <cedricjustine.encarnacion@analog.com>
+
+
+Description
+-----------
+
+The LTP8800 is a family of step-down μModule regulators that provides
+microprocessor core voltage from 54V power distribution architecture. LTP8800
+features telemetry monitoring of input/output voltage, input current, output
+power, and temperature over PMBus.
+
+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. Please see
+Documentation/hwmon/pmbus.rst for details.
+
+Sysfs Attributes
+----------------
+
+======================= ===========================
+curr1_label		"iin"
+curr1_input		Measured input current
+curr1_crit		Critical maximum current
+curr1_crit_alarm	Current critical high alarm
+
+curr2_label		"iout1"
+curr2_input		Measured output current
+curr2_lcrit		Critical minimum current
+curr2_crit		Critical maximum current
+curr2_max		Maximum output current
+curr2_alarm		Current alarm
+
+in1_label		"vin"
+in1_input		Measured input voltage
+in1_lcrit		Critical minimum input voltage
+in1_lcrit_alarm		Input voltage critical low alarm
+in1_crit		Critical maximum input voltage
+in1_crit_alarm		Input voltage critical high alarm
+
+in2_label		"vout1"
+in2_input		Measured output voltage
+in2_lcrit		Critical minimum output voltage
+in2_lcrit_alarm		Output voltage critical low alarm
+in2_crit		Critical maximum output voltage
+in2_crit_alarm		Output voltage critical high alarm
+in2_max			Maximum output voltage
+in2_max_alarm		Output voltage high alarm
+in2_min			Minimum output voltage
+in2_min_alarm		Output voltage low alarm
+
+power1_label		"pout1"
+power1_input		Measured output power
+power1_crit		Critical maximum output power
+
+temp1_input		Measured temperature
+temp1_lcrit		Critical low temperature
+temp1_lcrit_alarm		Chip temperature critical low alarm
+temp1_crit		Critical high temperature
+temp1_crit_alarm		Chiptemperature critical high alarm
+======================= ===========================

MAINTAINERS

@@ -12260,6 +12260,8 @@ M:	Cedric Encarnacion <cedricjustine.encarnacion@analog.com>
 L:	linux-hwmon@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,ltp8800.yaml
+F:	Documentation/hwmon/ltp8800.rst
+F:	drivers/hwmon/pmbus/ltp8800.c
 
 LYNX 28G SERDES PHY DRIVER
 M:	Ioana Ciornei <ioana.ciornei@nxp.com>

drivers/hwmon/pmbus/Kconfig

@@ -228,6 +228,24 @@ config SENSORS_LTC3815
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc3815.
 
+config SENSORS_LTP8800
+	tristate "Analog Devices LTP8800 and compatibles"
+	help
+	  If you say yes here you get hardware monitoring support for Analog
+	  Devices LTP8800-1A, LTP8800-4A, and LTP8800-2.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called ltp8800.
+
+config SENSORS_LTP8800_REGULATOR
+	bool "Regulator support for LTP8800 and compatibles"
+	depends on SENSORS_LTP8800 && REGULATOR
+	help
+	  If you say yes here you get regulator support for Analog Devices
+	  LTP8800-1A, LTP8800-4A, and LTP8800-2. LTP8800 is a family of DC/DC
+	  µModule regulators that can provide microprocessor power from 54V
+	  power distribution architecture.
+
 config SENSORS_MAX15301
 	tristate "Maxim MAX15301"
 	help

drivers/hwmon/pmbus/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o
 obj-$(CONFIG_SENSORS_LT7182S)	+= lt7182s.o
 obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o
 obj-$(CONFIG_SENSORS_LTC3815)	+= ltc3815.o
+obj-$(CONFIG_SENSORS_LTP8800)	+= ltp8800.o
 obj-$(CONFIG_SENSORS_MAX15301)	+= max15301.o
 obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o
 obj-$(CONFIG_SENSORS_MAX16601)	+= max16601.o

drivers/hwmon/pmbus/ltp8800.c

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware monitoring driver for Analog Devices LTP8800
+ *
+ * Copyright (C) 2024 Analog Devices, Inc.
+ */
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include "pmbus.h"
+
+static const struct regulator_desc __maybe_unused ltp8800_reg_desc[] = {
+	PMBUS_REGULATOR("vout", 0),
+};
+
+static struct pmbus_driver_info ltp8800_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = linear,
+	.format[PSC_CURRENT_IN] = linear,
+	.format[PSC_TEMPERATURE] = linear,
+	.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		   PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
+		   PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT |
+		   PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+		   PMBUS_HAVE_POUT,
+#if IS_ENABLED(CONFIG_SENSORS_LTP8800_REGULATOR)
+	.num_regulators = 1,
+	.reg_desc = ltp8800_reg_desc,
+#endif
+};
+
+/* 6.1 requires i2c_device_id */
+static int ltp8800_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_BYTE_DATA |
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENODEV;
+
+	return pmbus_do_probe(client, &ltp8800_info);
+}
+
+static const struct i2c_device_id ltp8800_id[] = {
+	{"ltp8800-1a", 0},
+	{"ltp8800-4a", 0},
+	{"ltp8800-2", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ltp8800_id);
+
+static const struct of_device_id ltp8800_of_match[] = {
+	{ .compatible = "adi,ltp8800-1a"},
+	{ .compatible = "adi,ltp8800-4a"},
+	{ .compatible = "adi,ltp8800-2"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, ltp8800_of_match);
+
+static struct i2c_driver ltp8800_driver = {
+	.driver = {
+		.name = "ltp8800",
+		.of_match_table = ltp8800_of_match,
+	},
+	.probe = ltp8800_probe,
+	.id_table = ltp8800_id,
+};
+module_i2c_driver(ltp8800_driver);
+
+MODULE_AUTHOR("Cedric Encarnacion <cedricjustine.encarnacion@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTP8800 HWMON PMBus Driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);