hwmon: (pmbus) Add support for pli1209bc

PLI1209BC is a Digital Supervisor from Vicor Corporation.
Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Link: https://lore.kernel.org/r/4e016e66275bc46c90974aec18b150c874e64787.1645435888.git.sylv@sylv.ioSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/index.rst

@@ -161,6 +161,7 @@ Hardware Monitoring Kernel Drivers
    pc87427
    pcf8591
    pim4328
+   pli1209bc
    pm6764tr
    pmbus
    powr1220

Documentation/hwmon/pli1209bc.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver pli1209bc
+=======================
+
+Supported chips:
+
+  * Digital Supervisor PLI1209BC
+
+    Prefix: 'pli1209bc'
+
+    Addresses scanned: 0x50 - 0x5F
+
+    Datasheet: https://www.vicorpower.com/documents/datasheets/ds-PLI1209BCxyzz-VICOR.pdf
+
+Authors:
+    - Marcello Sylvester Bauer <sylv@sylv.io>
+
+Description
+-----------
+
+The Vicor PLI1209BC is an isolated digital power system supervisor that provides
+a communication interface between a host processor and one Bus Converter Module
+(BCM). The PLI communicates with a system controller via a PMBus compatible
+interface over an isolated UART interface. Through the PLI, the host processor
+can configure, set protection limits, and monitor the BCM.
+
+Sysfs entries
+-------------
+
+======================= ========================================================
+in1_label		"vin2"
+in1_input		Input voltage.
+in1_rated_min		Minimum rated input voltage.
+in1_rated_max		Maximum rated input voltage.
+in1_max			Maximum input voltage.
+in1_max_alarm		Input voltage high alarm.
+in1_crit		Critical input voltage.
+in1_crit_alarm		Input voltage critical alarm.
+
+in2_label		"vout2"
+in2_input		Output voltage.
+in2_rated_min		Minimum rated output voltage.
+in2_rated_max		Maximum rated output voltage.
+in2_alarm		Output voltage alarm
+
+curr1_label		"iin2"
+curr1_input		Input current.
+curr1_max		Maximum input current.
+curr1_max_alarm		Maximum input current high alarm.
+curr1_crit		Critical input current.
+curr1_crit_alarm	Input current critical alarm.
+
+curr2_label		"iout2"
+curr2_input		Output current.
+curr2_crit		Critical output current.
+curr2_crit_alarm	Output current critical alarm.
+curr2_max		Maximum output current.
+curr2_max_alarm		Output current high alarm.
+
+power1_label		"pin2"
+power1_input		Input power.
+power1_alarm		Input power alarm.
+
+power2_label		"pout2"
+power2_input		Output power.
+power2_rated_max	Maximum rated output power.
+
+temp1_input		Die temperature.
+temp1_alarm		Die temperature alarm.
+temp1_max		Maximum die temperature.
+temp1_max_alarm		Die temperature high alarm.
+temp1_crit		Critical die temperature.
+temp1_crit_alarm	Die temperature critical alarm.
+======================= ========================================================

drivers/hwmon/pmbus/Kconfig

@@ -317,6 +317,15 @@ config SENSORS_PIM4328
 	  This driver can also be built as a module. If so, the module will
 	  be called pim4328.
 
+config SENSORS_PLI1209BC
+	tristate "Vicor PLI1209BC"
+	help
+	  If you say yes here you get hardware monitoring support for Vicor
+	  PLI1209BC Digital Supervisor.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called pli1209bc.
+
 config SENSORS_PM6764TR
 	tristate "ST PM6764TR"
 	help

drivers/hwmon/pmbus/Makefile

@@ -33,6 +33,7 @@ obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
 obj-$(CONFIG_SENSORS_MP2888)	+= mp2888.o
 obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o
+obj-$(CONFIG_SENSORS_PLI1209BC)	+= pli1209bc.o
 obj-$(CONFIG_SENSORS_PM6764TR)	+= pm6764tr.o
 obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
 obj-$(CONFIG_SENSORS_Q54SJ108A2)	+= q54sj108a2.o

drivers/hwmon/pmbus/pli1209bc.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Vicor PLI1209BC Digital Supervisor
+ *
+ * Copyright (c) 2022 9elements GmbH
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pmbus.h>
+#include "pmbus.h"
+
+/*
+ * The capability command is only supported at page 0. Probing the device while
+ * the page register is set to 1 will falsely enable PEC support. Disable
+ * capability probing accordingly, since the PLI1209BC does not have any
+ * additional capabilities.
+ */
+static struct pmbus_platform_data pli1209bc_plat_data = {
+	.flags = PMBUS_NO_CAPABILITY,
+};
+
+static int pli1209bc_read_word_data(struct i2c_client *client, int page,
+				    int phase, int reg)
+{
+	int data;
+
+	switch (reg) {
+	/* PMBUS_READ_POUT uses a direct format with R=0 */
+	case PMBUS_READ_POUT:
+		data = pmbus_read_word_data(client, page, phase, reg);
+		if (data < 0)
+			return data;
+		data = sign_extend32(data, 15) * 10;
+		return clamp_val(data, -32768, 32767) & 0xffff;
+	default:
+		return -ENODATA;
+	}
+}
+
+static struct pmbus_driver_info pli1209bc_info = {
+	.pages = 2,
+	.format[PSC_VOLTAGE_IN] = direct,
+	.format[PSC_VOLTAGE_OUT] = direct,
+	.format[PSC_CURRENT_IN] = direct,
+	.format[PSC_CURRENT_OUT] = direct,
+	.format[PSC_POWER] = direct,
+	.format[PSC_TEMPERATURE] = direct,
+	.m[PSC_VOLTAGE_IN] = 1,
+	.b[PSC_VOLTAGE_IN] = 0,
+	.R[PSC_VOLTAGE_IN] = 1,
+	.m[PSC_VOLTAGE_OUT] = 1,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = 1,
+	.m[PSC_CURRENT_IN] = 1,
+	.b[PSC_CURRENT_IN] = 0,
+	.R[PSC_CURRENT_IN] = 3,
+	.m[PSC_CURRENT_OUT] = 1,
+	.b[PSC_CURRENT_OUT] = 0,
+	.R[PSC_CURRENT_OUT] = 2,
+	.m[PSC_POWER] = 1,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = 1,
+	.m[PSC_TEMPERATURE] = 1,
+	.b[PSC_TEMPERATURE] = 0,
+	.R[PSC_TEMPERATURE] = 0,
+	/*
+	 * Page 0 sums up all attributes except voltage readings.
+	 * The pli1209 digital supervisor only contains a single BCM, making
+	 * page 0 redundant.
+	 */
+	.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT
+	    | PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT
+	    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
+	    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+	    | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT,
+	.read_word_data = pli1209bc_read_word_data,
+};
+
+static int pli1209bc_probe(struct i2c_client *client)
+{
+	client->dev.platform_data = &pli1209bc_plat_data;
+	return pmbus_do_probe(client, &pli1209bc_info);
+}
+
+static const struct i2c_device_id pli1209bc_id[] = {
+	{"pli1209bc", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, pli1209bc_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pli1209bc_of_match[] = {
+	{ .compatible = "vicor,pli1209bc" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pli1209bc_of_match);
+#endif
+
+static struct i2c_driver pli1209bc_driver = {
+	.driver = {
+		   .name = "pli1209bc",
+		   .of_match_table = of_match_ptr(pli1209bc_of_match),
+		   },
+	.probe_new = pli1209bc_probe,
+	.id_table = pli1209bc_id,
+};
+
+module_i2c_driver(pli1209bc_driver);
+
+MODULE_AUTHOR("Marcello Sylvester Bauer <sylv@sylv.io>");
+MODULE_DESCRIPTION("PMBus driver for Vicor PLI1209BC");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);