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>

4 files changed, 251 insertions, 0 deletions

diff --git a/Documentation/hwmon/isl68137 b/Documentation/hwmon/isl68137
new file mode 100644
index 000000000000..92e5c5fc5b77
--- /dev/null
+++ b/Documentation/hwmon/isl68137
@@ -0,0 +1,72 @@
+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
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index de87abab990e..7edab7e30eaf 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/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
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 7d1fa6b3c8c9..2219b9300316 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/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
diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c
new file mode 100644
index 000000000000..515596c92fe1
--- /dev/null
+++ b/drivers/hwmon/pmbus/isl68137.c
@@ -0,0 +1,169 @@
+// 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");