hwmon: (pmbus/isl68137) Add driver for Intersil ISL68137 PWM Controller

Intersil ISL68137 is a digital output 7-phase configurable PWM
controller with an AVSBus interface.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Signed-off-by: Robert Lippert <rlippert@google.com>
Signed-off-by: Patrick Venture <venture@google.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/isl68137

+Kernel driver isl68137
+======================
+
+Supported chips:
+  * Intersil ISL68137
+    Prefix: 'isl68137'
+    Addresses scanned: -
+    Datasheet: Publicly available at the Intersil website
+      https://www.intersil.com/content/dam/Intersil/documents/isl6/isl68137.pdf
+
+Authors:
+        Maxim Sloyko <maxims@google.com>
+        Robert Lippert <rlippert@google.com>
+        Patrick Venture <venture@google.com>
+
+Description
+-----------
+
+Intersil ISL68137 is a digital output 7-phase configurable PWM
+controller with an AVSBus interface.
+
+Usage Notes
+-----------
+
+This driver does not probe for PMBus devices. You will have to instantiate
+devices explicitly.
+
+The ISL68137 AVS operation mode must be enabled/disabled at runtime.
+
+Beyond the normal sysfs pmbus attributes, the driver exposes a control attribute.
+
+Additional Sysfs attributes
+---------------------------
+
+avs(0|1)_enable		Controls the AVS state of each rail.
+
+curr1_label		"iin"
+curr1_input		Measured input current
+curr1_crit		Critical maximum current
+curr1_crit_alarm	Current critical high alarm
+
+curr[2-3]_label		"iout[1-2]"
+curr[2-3]_input		Measured output current
+curr[2-3]_crit		Critical maximum current
+curr[2-3]_crit_alarm	Current critical high 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
+
+in[2-3]_label		"vout[1-2]"
+in[2-3]_input		Measured output voltage
+in[2-3]_lcrit		Critical minimum output voltage
+in[2-3]_lcrit_alarm	Output voltage critical low alarm
+in[2-3]_crit		Critical maximum output voltage
+in[2-3]_crit_alarm	Output voltage critical high alarm
+
+power1_label		"pin"
+power1_input		Measured input power
+power1_alarm		Input power high alarm
+
+power[2-3]_label	"pout[1-2]"
+power[2-3]_input	Measured output power
+
+temp[1-3]_input		Measured temperature
+temp[1-3]_crit		Critical high temperature
+temp[1-3]_crit_alarm	Chip temperature critical high alarm
+temp[1-3]_max		Maximum temperature
+temp[1-3]_max_alarm	Chip temperature high alarm

drivers/hwmon/pmbus/Kconfig

@@ -63,6 +63,15 @@ config SENSORS_IR38064
 	  This driver can also be built as a module. If so, the module will
 	  be called ir38064.
 
+config SENSORS_ISL68137
+	tristate "Intersil ISL68137"
+	help
+	  If you say yes here you get hardware monitoring support for Intersil
+	  ISL68137.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called isl68137.
+
 config SENSORS_LM25066
 	tristate "National Semiconductor LM25066 and compatibles"
 	help

drivers/hwmon/pmbus/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
 obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
 obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
 obj-$(CONFIG_SENSORS_IR38064)	+= ir38064.o
+obj-$(CONFIG_SENSORS_ISL68137)	+= isl68137.o
 obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o
 obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o
 obj-$(CONFIG_SENSORS_LTC3815)	+= ltc3815.o

drivers/hwmon/pmbus/isl68137.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Intersil ISL68137
+ *
+ * Copyright (c) 2017 Google Inc
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include "pmbus.h"
+
+#define ISL68137_VOUT_AVS	0x30
+
+static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client,
+					     int page,
+					     char *buf)
+{
+	int val = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
+
+	return sprintf(buf, "%d\n",
+		       (val & ISL68137_VOUT_AVS) == ISL68137_VOUT_AVS ? 1 : 0);
+}
+
+static ssize_t isl68137_avs_enable_store_page(struct i2c_client *client,
+					      int page,
+					      const char *buf, size_t count)
+{
+	int rc, op_val;
+	bool result;
+
+	rc = kstrtobool(buf, &result);
+	if (rc)
+		return rc;
+
+	op_val = result ? ISL68137_VOUT_AVS : 0;
+
+	/*
+	 * Writes to VOUT setpoint over AVSBus will persist after the VRM is
+	 * switched to PMBus control. Switching back to AVSBus control
+	 * restores this persisted setpoint rather than re-initializing to
+	 * PMBus VOUT_COMMAND. Writing VOUT_COMMAND first over PMBus before
+	 * enabling AVS control is the workaround.
+	 */
+	if (op_val == ISL68137_VOUT_AVS) {
+		rc = pmbus_read_word_data(client, page, PMBUS_VOUT_COMMAND);
+		if (rc < 0)
+			return rc;
+
+		rc = pmbus_write_word_data(client, page, PMBUS_VOUT_COMMAND,
+					   rc);
+		if (rc < 0)
+			return rc;
+	}
+
+	rc = pmbus_update_byte_data(client, page, PMBUS_OPERATION,
+				    ISL68137_VOUT_AVS, op_val);
+
+	return (rc < 0) ? rc : count;
+}
+
+static ssize_t isl68137_avs_enable_show(struct device *dev,
+					struct device_attribute *devattr,
+					char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return isl68137_avs_enable_show_page(client, attr->index, buf);
+}
+
+static ssize_t isl68137_avs_enable_store(struct device *dev,
+				struct device_attribute *devattr,
+				const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return isl68137_avs_enable_store_page(client, attr->index, buf, count);
+}
+
+static SENSOR_DEVICE_ATTR_RW(avs0_enable, isl68137_avs_enable, 0);
+static SENSOR_DEVICE_ATTR_RW(avs1_enable, isl68137_avs_enable, 1);
+
+static struct attribute *enable_attrs[] = {
+	&sensor_dev_attr_avs0_enable.dev_attr.attr,
+	&sensor_dev_attr_avs1_enable.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group enable_group = {
+	.attrs = enable_attrs,
+};
+
+static const struct attribute_group *attribute_groups[] = {
+	&enable_group,
+	NULL,
+};
+
+static struct pmbus_driver_info isl68137_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] = 3,
+	.m[PSC_VOLTAGE_OUT] = 1,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = 3,
+	.m[PSC_CURRENT_IN] = 1,
+	.b[PSC_CURRENT_IN] = 0,
+	.R[PSC_CURRENT_IN] = 2,
+	.m[PSC_CURRENT_OUT] = 1,
+	.b[PSC_CURRENT_OUT] = 0,
+	.R[PSC_CURRENT_OUT] = 1,
+	.m[PSC_POWER] = 1,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = 0,
+	.m[PSC_TEMPERATURE] = 1,
+	.b[PSC_TEMPERATURE] = 0,
+	.R[PSC_TEMPERATURE] = 0,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
+	    | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
+	    | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_TEMP
+	    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
+	.func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
+	.groups = attribute_groups,
+};
+
+static int isl68137_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	return pmbus_do_probe(client, id, &isl68137_info);
+}
+
+static const struct i2c_device_id isl68137_id[] = {
+	{"isl68137", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, isl68137_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver isl68137_driver = {
+	.driver = {
+		   .name = "isl68137",
+		   },
+	.probe = isl68137_probe,
+	.remove = pmbus_do_remove,
+	.id_table = isl68137_id,
+};
+
+module_i2c_driver(isl68137_driver);
+
+MODULE_AUTHOR("Maxim Sloyko <maxims@google.com>");
+MODULE_DESCRIPTION("PMBus driver for Intersil ISL68137");
+MODULE_LICENSE("GPL");