5 files changed, 440 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/hwmon/ibmpowernv.txt b/Documentation/devicetree/bindings/hwmon/ibmpowernv.txt
new file mode 100644
index 000000000000..f93242be60a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ibmpowernv.txt
@@ -0,0 +1,23 @@
+IBM POWERNV platform sensors
+----------------------------
+
+Required node properties:
+- compatible: must be one of
+                "ibm,opal-sensor-cooling-fan"
+                "ibm,opal-sensor-amb-temp"
+                "ibm,opal-sensor-power-supply"
+                "ibm,opal-sensor-power"
+- sensor-id: an opaque id provided by the firmware to the kernel, identifies a
+             given sensor and its attribute data
+
+Example sensors node:
+
+cooling-fan#8-data {
+        sensor-id = <0x7052107>;
+        compatible = "ibm,opal-sensor-cooling-fan";
+};
+
+amb-temp#1-thrs {
+        sensor-id = <0x5096000>;
+        compatible = "ibm,opal-sensor-amb-temp";
+};
diff --git a/Documentation/hwmon/ibmpowernv b/Documentation/hwmon/ibmpowernv
new file mode 100644
index 000000000000..8826ba29db36
--- /dev/null
+++ b/Documentation/hwmon/ibmpowernv
@@ -0,0 +1,41 @@
+Kernel Driver IBMPOWERNV
+========================
+
+Supported systems:
+  * Any recent IBM P servers based on POWERNV platform
+
+Author: Neelesh Gupta
+
+Description
+-----------
+
+This driver implements reading the platform sensors data like temperature/fan/
+voltage/power for 'POWERNV' platform.
+
+The driver uses the platform device infrastructure. It probes the device tree
+for sensor devices during the __init phase and registers them with the 'hwmon'.
+'hwmon' populates the 'sysfs' tree having attribute files, each for a given
+sensor type and its attribute data.
+
+All the nodes in the DT appear under "/ibm,opal/sensors" and each valid node in
+the DT maps to an attribute file in 'sysfs'. The node exports unique 'sensor-id'
+which the driver uses to make an OPAL call to the firmware.
+
+Usage notes
+-----------
+The driver is built statically with the kernel by enabling the config
+CONFIG_SENSORS_IBMPOWERNV. It can also be built as module 'ibmpowernv'.
+
+Sysfs attributes
+----------------
+
+fanX_input              Measured RPM value.
+fanX_min                Threshold RPM for alert generation.
+fanX_fault              0: No fail condition
+                        1: Failing fan
+tempX_input             Measured ambient temperature.
+tempX_max               Threshold ambient temperature for alert generation.
+inX_input               Measured power supply voltage
+inX_fault               0: No fail condition.
+                        1: Failing power supply.
+power1_input            System power consumption (microWatt)
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 37908ff8f7ff..c0aec8db462f 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -554,6 +554,17 @@ config SENSORS_IBMPEX
           This driver can also be built as a module.  If so, the module
           will be called ibmpex.
 
+config SENSORS_IBMPOWERNV
+        tristate "IBM POWERNV platform sensors"
+        depends on PPC_POWERNV
+        default y
+        help
+          If you say yes here you get support for the temperature/fan/power
+          sensors on your PowerNV platform.
+
+          This driver can also be built as a module. If so, the module
+          will be called ibmpowernv.
+
 config SENSORS_IIO_HWMON
         tristate "Hwmon driver that uses channels specified via iio maps"
         depends on IIO
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 1362382a3187..f4435ea6b169 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
 obj-$(CONFIG_SENSORS_I5K_AMB)   += i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)    += ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)    += ibmpex.o
+obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
 obj-$(CONFIG_SENSORS_INA209)    += ina209.o
 obj-$(CONFIG_SENSORS_INA2XX)    += ina2xx.o
diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
new file mode 100644
index 000000000000..e6b652a35815
--- /dev/null
+++ b/drivers/hwmon/ibmpowernv.c
@@ -0,0 +1,364 @@
+/*
+ * IBM PowerNV platform sensors for temperature/fan/voltage/power
+ * Copyright (C) 2014 IBM
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ */
+
+#define DRVNAME         "ibmpowernv"
+#define pr_fmt(fmt)     DRVNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <linux/platform_device.h>
+#include <asm/opal.h>
+#include <linux/err.h>
+
+#define MAX_ATTR_LEN    32
+
+/* Sensor suffix name from DT */
+#define DT_FAULT_ATTR_SUFFIX            "faulted"
+#define DT_DATA_ATTR_SUFFIX             "data"
+#define DT_THRESHOLD_ATTR_SUFFIX        "thrs"
+
+/*
+ * Enumerates all the types of sensors in the POWERNV platform and does index
+ * into 'struct sensor_group'
+ */
+enum sensors {
+        FAN,
+        AMBIENT_TEMP,
+        POWER_SUPPLY,
+        POWER_INPUT,
+        MAX_SENSOR_TYPE,
+};
+
+static struct sensor_group {
+        const char *name;
+        const char *compatible;
+        struct attribute_group group;
+        u32 attr_count;
+} sensor_groups[] = {
+        {"fan", "ibm,opal-sensor-cooling-fan"},
+        {"temp", "ibm,opal-sensor-amb-temp"},
+        {"in", "ibm,opal-sensor-power-supply"},
+        {"power", "ibm,opal-sensor-power"}
+};
+
+struct sensor_data {
+        u32 id; /* An opaque id of the firmware for each sensor */
+        enum sensors type;
+        char name[MAX_ATTR_LEN];
+        struct device_attribute dev_attr;
+};
+
+struct platform_data {
+        const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
+        u32 sensors_count; /* Total count of sensors from each group */
+};
+
+/* Platform device representing all the ibmpowernv sensors */
+static struct platform_device *pdevice;
+
+static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
+                           char *buf)
+{
+        struct sensor_data *sdata = container_of(devattr, struct sensor_data,
+                                                 dev_attr);
+        ssize_t ret;
+        u32 x;
+
+        ret = opal_get_sensor_data(sdata->id, &x);
+        if (ret)
+                return ret;
+
+        /* Convert temperature to milli-degrees */
+        if (sdata->type == AMBIENT_TEMP)
+                x *= 1000;
+        /* Convert power to micro-watts */
+        else if (sdata->type == POWER_INPUT)
+                x *= 1000000;
+
+        return sprintf(buf, "%u\n", x);
+}
+
+static int __init get_sensor_index_attr(const char *name, u32 *index,
+                                        char *attr)
+{
+        char *hash_pos = strchr(name, '#');
+        char buf[8] = { 0 };
+        char *dash_pos;
+        u32 copy_len;
+        int err;
+
+        if (!hash_pos)
+                return -EINVAL;
+
+        dash_pos = strchr(hash_pos, '-');
+        if (!dash_pos)
+                return -EINVAL;
+
+        copy_len = dash_pos - hash_pos - 1;
+        if (copy_len >= sizeof(buf))
+                return -EINVAL;
+
+        strncpy(buf, hash_pos + 1, copy_len);
+
+        err = kstrtou32(buf, 10, index);
+        if (err)
+                return err;
+
+        strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
+
+        return 0;
+}
+
+/*
+ * This function translates the DT node name into the 'hwmon' attribute name.
+ * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
+ * which need to be mapped as fan2_input, temp1_max respectively before
+ * populating them inside hwmon device class.
+ */
+static int __init create_hwmon_attr_name(struct device *dev, enum sensors type,
+                                         const char *node_name,
+                                         char *hwmon_attr_name)
+{
+        char attr_suffix[MAX_ATTR_LEN];
+        char *attr_name;
+        u32 index;
+        int err;
+
+        err = get_sensor_index_attr(node_name, &index, attr_suffix);
+        if (err) {
+                dev_err(dev, "Sensor device node name '%s' is invalid\n",
+                        node_name);
+                return err;
+        }
+
+        if (!strcmp(attr_suffix, DT_FAULT_ATTR_SUFFIX)) {
+                attr_name = "fault";
+        } else if (!strcmp(attr_suffix, DT_DATA_ATTR_SUFFIX)) {
+                attr_name = "input";
+        } else if (!strcmp(attr_suffix, DT_THRESHOLD_ATTR_SUFFIX)) {
+                if (type == AMBIENT_TEMP)
+                        attr_name = "max";
+                else if (type == FAN)
+                        attr_name = "min";
+                else
+                        return -ENOENT;
+        } else {
+                return -ENOENT;
+        }
+
+        snprintf(hwmon_attr_name, MAX_ATTR_LEN, "%s%d_%s",
+                 sensor_groups[type].name, index, attr_name);
+        return 0;
+}
+
+static int __init populate_attr_groups(struct platform_device *pdev)
+{
+        struct platform_data *pdata = platform_get_drvdata(pdev);
+        const struct attribute_group **pgroups = pdata->attr_groups;
+        struct device_node *opal, *np;
+        enum sensors type;
+
+        opal = of_find_node_by_path("/ibm,opal/sensors");
+        if (!opal) {
+                dev_err(&pdev->dev, "Opal node 'sensors' not found\n");
+                return -ENODEV;
+        }
+
+        for_each_child_of_node(opal, np) {
+                if (np->name == NULL)
+                        continue;
+
+                for (type = 0; type < MAX_SENSOR_TYPE; type++)
+                        if (of_device_is_compatible(np,
+                                        sensor_groups[type].compatible)) {
+                                sensor_groups[type].attr_count++;
+                                break;
+                        }
+        }
+
+        of_node_put(opal);
+
+        for (type = 0; type < MAX_SENSOR_TYPE; type++) {
+                sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
+                                        sizeof(struct attribute *) *
+                                        (sensor_groups[type].attr_count + 1),
+                                        GFP_KERNEL);
+                if (!sensor_groups[type].group.attrs)
+                        return -ENOMEM;
+
+                pgroups[type] = &sensor_groups[type].group;
+                pdata->sensors_count += sensor_groups[type].attr_count;
+                sensor_groups[type].attr_count = 0;
+        }
+
+        return 0;
+}
+
+/*
+ * Iterate through the device tree for each child of 'sensors' node, create
+ * a sysfs attribute file, the file is named by translating the DT node name
+ * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
+ * etc..
+ */
+static int __init create_device_attrs(struct platform_device *pdev)
+{
+        struct platform_data *pdata = platform_get_drvdata(pdev);
+        const struct attribute_group **pgroups = pdata->attr_groups;
+        struct device_node *opal, *np;
+        struct sensor_data *sdata;
+        const __be32 *sensor_id;
+        enum sensors type;
+        u32 count = 0;
+        int err = 0;
+
+        opal = of_find_node_by_path("/ibm,opal/sensors");
+        sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
+                             GFP_KERNEL);
+        if (!sdata) {
+                err = -ENOMEM;
+                goto exit_put_node;
+        }
+
+        for_each_child_of_node(opal, np) {
+                if (np->name == NULL)
+                        continue;
+
+                for (type = 0; type < MAX_SENSOR_TYPE; type++)
+                        if (of_device_is_compatible(np,
+                                        sensor_groups[type].compatible))
+                                break;
+
+                if (type == MAX_SENSOR_TYPE)
+                        continue;
+
+                sensor_id = of_get_property(np, "sensor-id", NULL);
+                if (!sensor_id) {
+                        dev_info(&pdev->dev,
+                                 "'sensor-id' missing in the node '%s'\n",
+                                 np->name);
+                        continue;
+                }
+
+                sdata[count].id = be32_to_cpup(sensor_id);
+                sdata[count].type = type;
+                err = create_hwmon_attr_name(&pdev->dev, type, np->name,
+                                             sdata[count].name);
+                if (err)
+                        goto exit_put_node;
+
+                sysfs_attr_init(&sdata[count].dev_attr.attr);
+                sdata[count].dev_attr.attr.name = sdata[count].name;
+                sdata[count].dev_attr.attr.mode = S_IRUGO;
+                sdata[count].dev_attr.show = show_sensor;
+
+                pgroups[type]->attrs[sensor_groups[type].attr_count++] =
+                                &sdata[count++].dev_attr.attr;
+        }
+
+exit_put_node:
+        of_node_put(opal);
+        return err;
+}
+
+static int __init ibmpowernv_probe(struct platform_device *pdev)
+{
+        struct platform_data *pdata;
+        struct device *hwmon_dev;
+        int err;
+
+        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, pdata);
+        pdata->sensors_count = 0;
+        err = populate_attr_groups(pdev);
+        if (err)
+                return err;
+
+        /* Create sysfs attribute data for each sensor found in the DT */
+        err = create_device_attrs(pdev);
+        if (err)
+                return err;
+
+        /* Finally, register with hwmon */
+        hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
+                                                           pdata,
+                                                           pdata->attr_groups);
+
+        return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct platform_driver ibmpowernv_driver = {
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = DRVNAME,
+        },
+};
+
+static int __init ibmpowernv_init(void)
+{
+        int err;
+
+        pdevice = platform_device_alloc(DRVNAME, 0);
+        if (!pdevice) {
+                pr_err("Device allocation failed\n");
+                err = -ENOMEM;
+                goto exit;
+        }
+
+        err = platform_device_add(pdevice);
+        if (err) {
+                pr_err("Device addition failed (%d)\n", err);
+                goto exit_device_put;
+        }
+
+        err = platform_driver_probe(&ibmpowernv_driver, ibmpowernv_probe);
+        if (err) {
+                pr_err("Platfrom driver probe failed\n");
+                goto exit_device_del;
+        }
+
+        return 0;
+
+exit_device_del:
+        platform_device_del(pdevice);
+exit_device_put:
+        platform_device_put(pdevice);
+exit:
+        return err;
+}
+
+static void __exit ibmpowernv_exit(void)
+{
+        platform_driver_unregister(&ibmpowernv_driver);
+        platform_device_unregister(pdevice);
+}
+
+MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("IBM POWERNV platform sensors");
+MODULE_LICENSE("GPL");
+
+module_init(ibmpowernv_init);
+module_exit(ibmpowernv_exit);