[RFC 2/2] hwmon: powernv: Hwmon driver for OCC inband power and temperature sensors

From: Shilpasri G Bhat
Date: Thu Mar 09 2017 - 06:53:08 EST


Add support to read power and temperature sensors from OCC inband
sensors which are copied to main memory by OCC.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>
CC: Rob Herring <robh+dt@xxxxxxxxxx>
CC: Mark Rutland <mark.rutland@xxxxxxx>
CC: Jean Delvare <jdelvare@xxxxxxxx>
CC: Guenter Roeck <linux@xxxxxxxxxxxx>
CC: Jonathan Corbet <corbet@xxxxxxx>
CC: devicetree@xxxxxxxxxxxxxxx
CC: linux-hwmon@xxxxxxxxxxxxxxx
CC: linux-doc@xxxxxxxxxxxxxxx
---
.../devicetree/bindings/hwmon/ibmpowernv-occ.txt | 4 +
Documentation/hwmon/ibmpowernv-occ | 24 ++
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/ibmpowernv-occ.c | 302 +++++++++++++++++++++
5 files changed, 342 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
create mode 100644 Documentation/hwmon/ibmpowernv-occ
create mode 100644 drivers/hwmon/ibmpowernv-occ.c

diff --git a/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt b/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
new file mode 100644
index 0000000..d03f744
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
@@ -0,0 +1,4 @@
+IBM POWERNV OCC inband platform sensors
+
+Required device-tree property:
+- compatible: "ibm,p9-occ-inband-sensor"
diff --git a/Documentation/hwmon/ibmpowernv-occ b/Documentation/hwmon/ibmpowernv-occ
new file mode 100644
index 0000000..151028b
--- /dev/null
+++ b/Documentation/hwmon/ibmpowernv-occ
@@ -0,0 +1,24 @@
+Kernel driver ibmpowernv-occ
+=============================
+
+Supported systems:
+ * P9 server based on POWERNV platform
+
+Description
+------------
+
+This driver exports the power and temperature sensors from OCC inband
+sensors on P9 POWERNV platforms.
+
+Sysfs attributes
+----------------
+
+powerX_input Latest power reading
+powerX_input_highest Minimum power
+powerX_input_lowest Maximum power
+powerX_label Sensor name
+
+tempX_input Latest temperature reading
+tempX_max Minimum temperature
+tempX_min Maximum temperature
+tempX_label Sensor name
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0649d53f3..3b1dbb9 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -598,6 +598,17 @@ config SENSORS_IBMPOWERNV
This driver can also be built as a module. If so, the module
will be called ibmpowernv.

+config SENSORS_IBMPOWERNV_OCC
+ tristate "IBM POWERNV OCC Inband platform sensors"
+ depends on PPC_POWERNV
+ default y
+ help
+ If you say yes here you get support for the temperature/power
+ OCC inband sensors on your PowerNV platform.
+
+ This driver can also be built as a module. If so, the module
+ will be called ibmpowernv-occ.
+
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 5509edf..0da2207 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -75,6 +75,7 @@ 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-$(CONFIG_SENSORS_IBMPOWERNV_OCC)+= ibmpowernv-occ.o
obj-$(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-occ.c b/drivers/hwmon/ibmpowernv-occ.c
new file mode 100644
index 0000000..97b1bbe
--- /dev/null
+++ b/drivers/hwmon/ibmpowernv-occ.c
@@ -0,0 +1,302 @@
+/*
+ * IBM PowerNV platform OCC inband sensors for temperature/power
+ * Copyright (C) 2017 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_occ"
+#define pr_fmt(fmt) DRVNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/hwmon.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include <asm/opal.h>
+
+#define MAX_HWMON_ATTR_LEN 32
+#define MAX_HWMON_LABEL_LEN (MAX_OCC_SENSOR_NAME_LEN * 2)
+#define HWMON_ATTRS_PER_SENSOR 16
+#define TO_MILLI_UNITS(x) ((x) * 1000)
+#define TO_MICRO_UNITS(x) ((x) * 1000000)
+
+enum sensors {
+ TEMP,
+ POWER,
+ MAX_SENSOR_TYPE,
+};
+
+static struct sensor_type {
+ const char *name;
+ int hwmon_id;
+} sensor_types[] = {
+ { "temp"},
+ { "power"},
+};
+
+static struct sensor_data {
+ u32 occ_id;
+ u64 offset; /* Offset to ping/pong reading buffer */
+ enum sensors type;
+ char label[MAX_HWMON_LABEL_LEN];
+ char name[MAX_HWMON_ATTR_LEN];
+ struct device_attribute attr;
+} *sdata;
+
+static struct attribute_group sensor_attrs_group;
+__ATTRIBUTE_GROUPS(sensor_attrs);
+
+#define show(file_name) \
+static ssize_t ibmpowernv_occ_show_##file_name \
+(struct device *dev, struct device_attribute *dattr, char *buf) \
+{ \
+ struct sensor_data *sdata = container_of(dattr, \
+ struct sensor_data, \
+ attr); \
+ u64 val; \
+ int ret; \
+ ret = opal_occ_sensor_get_##file_name(sdata->occ_id, \
+ sdata->offset, \
+ &val); \
+ if (ret) \
+ return ret; \
+ if (sdata->type == TEMP) \
+ val = TO_MILLI_UNITS(val); \
+ else if (sdata->type == POWER) \
+ val = TO_MICRO_UNITS(val); \
+ return sprintf(buf, "%llu\n", val); \
+}
+
+show(sample);
+show(max);
+show(min);
+show(js_min);
+show(js_max);
+show(csm_min);
+show(csm_max);
+show(prof_min);
+show(prof_max);
+
+static struct sensor_view_groups {
+ const char *name;
+ ssize_t (*show_sample)(struct device *dev,
+ struct device_attribute *attr,
+ char *buf);
+ ssize_t (*show_min)(struct device *dev,
+ struct device_attribute *attr,
+ char *buf);
+ ssize_t (*show_max)(struct device *dev,
+ struct device_attribute *attr,
+ char *buf);
+} sensor_views[] = {
+ {
+ .name = "",
+ .show_sample = ibmpowernv_occ_show_sample,
+ .show_min = ibmpowernv_occ_show_min,
+ .show_max = ibmpowernv_occ_show_max
+ },
+ {
+ .name = "_JS",
+ .show_sample = ibmpowernv_occ_show_sample,
+ .show_min = ibmpowernv_occ_show_js_min,
+ .show_max = ibmpowernv_occ_show_js_max
+ },
+ { .name = "_CSM",
+ .show_sample = ibmpowernv_occ_show_sample,
+ .show_min = ibmpowernv_occ_show_csm_min,
+ .show_max = ibmpowernv_occ_show_csm_max
+ },
+ { .name = "_Prof",
+ .show_sample = ibmpowernv_occ_show_sample,
+ .show_min = ibmpowernv_occ_show_prof_min,
+ .show_max = ibmpowernv_occ_show_prof_max
+ },
+};
+
+static ssize_t ibmpowernv_occ_show_label(struct device *dev,
+ struct device_attribute *dattr,
+ char *buf)
+{
+ struct sensor_data *sdata = container_of(dattr, struct sensor_data,
+ attr);
+
+ return sprintf(buf, "%s\n", sdata->label);
+}
+
+static int ibmpowernv_occ_get_sensor_type(enum occ_sensor_type type)
+{
+ switch (type) {
+ case OCC_SENSOR_TYPE_POWER:
+ return POWER;
+ case OCC_SENSOR_TYPE_TEMPERATURE:
+ return TEMP;
+ default:
+ return MAX_SENSOR_TYPE;
+ }
+
+ return MAX_SENSOR_TYPE;
+}
+
+static void ibmpowernv_occ_add_sdata(struct occ_hwmon_sensor sensor,
+ struct sensor_data *sdata, char *name,
+ int hwmon_id, enum sensors type,
+ ssize_t (*show)(struct device *dev,
+ struct device_attribute *attr,
+ char *buf))
+{
+ sdata->type = type;
+ sdata->occ_id = sensor.occ_id;
+ sdata->offset = sensor.offset;
+ snprintf(sdata->name, MAX_HWMON_ATTR_LEN, "%s%d_%s",
+ sensor_types[type].name, hwmon_id, name);
+ sysfs_attr_init(&sdata->attr.attr);
+ sdata->attr.attr.name = sdata->name;
+ sdata->attr.attr.mode = 0444;
+ sdata->attr.show = show;
+}
+
+static void ibmpowernv_occ_add_sensor_attrs(struct occ_hwmon_sensor sensor,
+ int index)
+{
+ struct attribute **attrs = sensor_attrs_group.attrs;
+ char attr_str[MAX_HWMON_ATTR_LEN];
+ enum sensors type = ibmpowernv_occ_get_sensor_type(sensor.type);
+ int i;
+
+ index *= HWMON_ATTRS_PER_SENSOR;
+ for (i = 0; i < ARRAY_SIZE(sensor_views); i++) {
+ int hid = ++sensor_types[type].hwmon_id;
+
+ /* input */
+ ibmpowernv_occ_add_sdata(sensor, &sdata[index], "input", hid,
+ type, sensor_views[i].show_sample);
+ attrs[index] = &sdata[index].attr.attr;
+ index++;
+
+ /* min */
+ if (type == POWER)
+ snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s",
+ "input_lowest");
+ else
+ snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s", "min");
+
+ ibmpowernv_occ_add_sdata(sensor, &sdata[index], attr_str, hid,
+ type, sensor_views[i].show_min);
+ attrs[index] = &sdata[index].attr.attr;
+ index++;
+
+ /* max */
+ if (type == POWER)
+ snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s",
+ "input_highest");
+ else
+ snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s", "max");
+
+ ibmpowernv_occ_add_sdata(sensor, &sdata[index], attr_str, hid,
+ type, sensor_views[i].show_max);
+ attrs[index] = &sdata[index].attr.attr;
+ index++;
+
+ /* label */
+ snprintf(sdata[index].label, MAX_HWMON_LABEL_LEN, "%s%s",
+ sensor.name, sensor_views[i].name);
+ ibmpowernv_occ_add_sdata(sensor, &sdata[index], "label", hid,
+ type, ibmpowernv_occ_show_label);
+ attrs[index] = &sdata[index].attr.attr;
+ index++;
+ }
+}
+
+static int ibmpowernv_occ_add_device_attrs(struct platform_device *pdev)
+{
+ struct attribute **attrs;
+ struct occ_hwmon_sensor *slist = NULL;
+ int nr_sensors = 0, i;
+ int ret = -ENOMEM;
+
+ slist = opal_occ_sensor_get_hwmon_list(&nr_sensors);
+ if (!nr_sensors)
+ return -ENODEV;
+
+ if (!slist)
+ return ret;
+
+ sdata = devm_kzalloc(&pdev->dev, nr_sensors * sizeof(*sdata) *
+ HWMON_ATTRS_PER_SENSOR, GFP_KERNEL);
+ if (!sdata)
+ goto out;
+
+ attrs = devm_kzalloc(&pdev->dev, nr_sensors * sizeof(*attrs) *
+ HWMON_ATTRS_PER_SENSOR, GFP_KERNEL);
+ if (!attrs)
+ goto out;
+
+ sensor_attrs_group.attrs = attrs;
+ for (i = 0; i < nr_sensors; i++)
+ ibmpowernv_occ_add_sensor_attrs(slist[i], i);
+
+ ret = 0;
+out:
+ kfree(slist);
+ return ret;
+}
+
+static int ibmpowernv_occ_probe(struct platform_device *pdev)
+{
+ struct device *hwmon_dev;
+ int err;
+
+ err = ibmpowernv_occ_add_device_attrs(pdev);
+ if (err)
+ goto out;
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
+ NULL,
+ sensor_attrs_groups);
+
+ err = PTR_ERR_OR_ZERO(hwmon_dev);
+out:
+ if (err)
+ pr_warn("Failed to initialize Hwmon OCC inband sensors\n");
+
+ return err;
+}
+
+static const struct platform_device_id occ_sensor_ids[] = {
+ { .name = "occ-inband-sensor" },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, occ_sensor_ids);
+
+static const struct of_device_id occ_sensor_of_ids[] = {
+ { .compatible = "ibm,p9-occ-inband-sensor" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, occ_sensor_of_ids);
+
+static struct platform_driver ibmpowernv_occ_driver = {
+ .probe = ibmpowernv_occ_probe,
+ .id_table = occ_sensor_ids,
+ .driver = {
+ .name = DRVNAME,
+ .of_match_table = occ_sensor_of_ids,
+ },
+};
+
+module_platform_driver(ibmpowernv_occ_driver);
+
+MODULE_AUTHOR("Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("IBM POWERNV platform OCC inband sensors");
+MODULE_LICENSE("GPL");
--
1.8.3.1