[PATCH linux 2/7] hwmon: occ: Add sysfs interface
eajames.ibm at gmail.com
eajames.ibm at gmail.com
Sat Dec 17 07:34:56 AEDT 2016
From: "Edward A. James" <eajames at us.ibm.com>
Add a generic mechanism to expose the sensors provided by the OCC in
sysfs.
Signed-off-by: Edward A. James <eajames at us.ibm.com>
Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
Documentation/hwmon/occ | 48 +++++
drivers/hwmon/occ/Makefile | 2 +-
drivers/hwmon/occ/occ_sysfs.c | 492 ++++++++++++++++++++++++++++++++++++++++++
drivers/hwmon/occ/occ_sysfs.h | 52 +++++
4 files changed, 593 insertions(+), 1 deletion(-)
create mode 100644 drivers/hwmon/occ/occ_sysfs.c
create mode 100644 drivers/hwmon/occ/occ_sysfs.h
diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
index 79d1642..1ee8689 100644
--- a/Documentation/hwmon/occ
+++ b/Documentation/hwmon/occ
@@ -25,6 +25,54 @@ Currently, all versions of the OCC support four types of sensor data: power,
temperature, frequency, and "caps," which indicate limits and thresholds used
internally on the OCC.
+sysfs Entries
+-------------
+
+The OCC driver uses the hwmon sysfs framework to provide data to userspace.
+
+The driver exports two sysfs files for each frequency, temperature, and power
+sensor. These are "input" and "label". The input file contains the value of the
+sensor. The label file contains the sensor id. The sensor id is the unique
+internal OCC identifier. Sensor ids may be provided by the OCC specification.
+The names of these files will be in the following format:
+ <sensor type><sensor index>_input
+ <sensor type><sensor index>_label
+Sensor types will be one of "temp", "freq", or "power". The sensor index is
+an index to differentiate different sensor files. For example, a single
+temperature sensor will have two sysfs files: temp1_input and temp1_label.
+
+Caps sensors are exported differently. For each caps sensor, the driver will
+export 6 entries:
+ curr_powercap - current power cap in watts
+ curr_powerreading - current power output in watts
+ norm_powercap - power cap without redundant power
+ max_powercap - maximum power cap that can be set in watts
+ min_powercap - minimum power cap that can be set in watts
+ user_powerlimit - power limit specified by the user in watts
+In addition, the OCC driver for P9 will export a 7th entry:
+ user_powerlimit_source - can be one of two values depending on who set
+ the user_powerlimit. 0x1 - out of band from BMC or host. 0x2 -
+ in band from other source.
+The format for these files is caps<sensor index>_<entry type>. For example,
+caps1_curr_powercap.
+
+The driver also provides a number of sysfs entries through hwmon to better
+control the driver and monitor the OCC.
+ powercap - read or write the OCC user power limit in watts.
+ name - read the name of the driver
+ update_interval - read or write the minimum interval for polling the
+ OCC.
+
+The driver also exports a single sysfs file through the communication protocol
+device (see BMC - Host Communications). The filename is "online" and represents
+the status of the OCC with respect to the driver. The OCC can be in one of two
+states: OCC polling enabled or OCC polling disabled. The purpose of this file
+is to control the behavior of the driver and it's hwmon sysfs entries, not to
+infer any information about the state of the physical OCC. Reading the file
+returns either a 0 (polling disabled) or 1 (polling enabled). Writing 1 to the
+file enables OCC polling in the driver if communications can be established
+with the OCC. Writing a 0 to the driver disables OCC polling.
+
BMC - Host Communications
-------------------------
diff --git a/drivers/hwmon/occ/Makefile b/drivers/hwmon/occ/Makefile
index 93cb52f..a6881f9 100644
--- a/drivers/hwmon/occ/Makefile
+++ b/drivers/hwmon/occ/Makefile
@@ -1 +1 @@
-obj-$(CONFIG_SENSORS_PPC_OCC) += occ.o
+obj-$(CONFIG_SENSORS_PPC_OCC) += occ.o occ_sysfs.o
diff --git a/drivers/hwmon/occ/occ_sysfs.c b/drivers/hwmon/occ/occ_sysfs.c
new file mode 100644
index 0000000..b0e063da
--- /dev/null
+++ b/drivers/hwmon/occ/occ_sysfs.c
@@ -0,0 +1,492 @@
+/*
+ * occ_sysfs.c - OCC sysfs interface
+ *
+ * This file contains the methods and data structures for implementing the OCC
+ * hwmon sysfs entries.
+ *
+ * Copyright 2016 IBM Corp.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include "occ_sysfs.h"
+
+#define MAX_SENSOR_ATTR_LEN 32
+
+#define RESP_RETURN_CMD_INVAL 0x13
+
+struct sensor_attr_data {
+ enum sensor_type type;
+ u32 hwmon_index;
+ u32 attr_id;
+ char name[MAX_SENSOR_ATTR_LEN];
+ struct device_attribute dev_attr;
+};
+
+static ssize_t show_input(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int val;
+ struct sensor_attr_data *sdata = container_of(attr,
+ struct sensor_attr_data,
+ dev_attr);
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ val = occ_get_sensor_value(driver->occ, sdata->type,
+ sdata->hwmon_index - 1);
+ if (sdata->type == TEMP)
+ val *= 1000; /* in millidegree Celsius */
+
+ return snprintf(buf, PAGE_SIZE - 1, "%d\n", val);
+}
+
+/* show_label provides the OCC sensor id. The sensor id will be either a
+ * 2-byte (for P8) or 4-byte (for P9) value. The sensor id is a way to
+ * identify what each sensor represents, according to the OCC specification.
+ */
+static ssize_t show_label(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int val;
+ struct sensor_attr_data *sdata = container_of(attr,
+ struct sensor_attr_data,
+ dev_attr);
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ val = occ_get_sensor_id(driver->occ, sdata->type,
+ sdata->hwmon_index - 1);
+
+ return snprintf(buf, PAGE_SIZE - 1, "%d\n", val);
+}
+
+static ssize_t show_caps(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int val;
+ struct caps_sensor *sensor;
+ struct sensor_attr_data *sdata = container_of(attr,
+ struct sensor_attr_data,
+ dev_attr);
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ sensor = occ_get_sensor(driver->occ, CAPS);
+ if (!sensor) {
+ val = -1;
+ return snprintf(buf, PAGE_SIZE - 1, "%d\n", val);
+ }
+
+ val = occ_get_caps_value(driver->occ, sensor, sdata->hwmon_index - 1,
+ sdata->attr_id);
+
+ return snprintf(buf, PAGE_SIZE - 1, "%d\n", val);
+}
+
+static ssize_t show_update_interval(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE - 1, "%lu\n", driver->update_interval);
+}
+
+static ssize_t store_update_interval(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+ unsigned long val;
+ int rc;
+
+ rc = kstrtoul(buf, 10, &val);
+ if (rc)
+ return rc;
+
+ driver->update_interval = val;
+ occ_set_update_interval(driver->occ, val);
+
+ return count;
+}
+
+static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_update_interval,
+ store_update_interval);
+
+static ssize_t show_name(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE - 1, "occ\n");
+}
+
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static ssize_t show_user_powercap(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE - 1, "%u\n", driver->user_powercap);
+}
+
+static ssize_t store_user_powercap(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+ u16 val;
+ int rc;
+
+ rc = kstrtou16(buf, 10, &val);
+ if (rc)
+ return rc;
+
+ dev_dbg(dev, "set user powercap to: %d\n", val);
+ rc = occ_set_user_powercap(driver->occ, val);
+ if (rc) {
+ dev_err(dev, "set user powercap failed: 0x%x\n", rc);
+ if (rc == RESP_RETURN_CMD_INVAL) {
+ dev_err(dev, "set invalid powercap value: %d\n", val);
+ return -EINVAL;
+ }
+
+ return rc;
+ }
+
+ driver->user_powercap = val;
+
+ return count;
+}
+
+static DEVICE_ATTR(user_powercap, S_IWUSR | S_IRUGO, show_user_powercap,
+ store_user_powercap);
+
+static void deinit_sensor_groups(struct device *dev,
+ struct sensor_group *sensor_groups)
+{
+ int i;
+
+ for (i = 0; i < MAX_OCC_SENSOR_TYPE; i++) {
+ if (sensor_groups[i].group.attrs)
+ devm_kfree(dev, sensor_groups[i].group.attrs);
+ if (sensor_groups[i].sattr)
+ devm_kfree(dev, sensor_groups[i].sattr);
+ sensor_groups[i].group.attrs = NULL;
+ sensor_groups[i].sattr = NULL;
+ }
+}
+
+static void sensor_attr_init(struct sensor_attr_data *sdata,
+ char *sensor_group_name,
+ char *attr_name,
+ ssize_t (*show)(struct device *dev,
+ struct device_attribute *attr,
+ char *buf))
+{
+ sysfs_attr_init(&sdata->dev_attr.attr);
+
+ snprintf(sdata->name, MAX_SENSOR_ATTR_LEN, "%s%d_%s",
+ sensor_group_name, sdata->hwmon_index, attr_name);
+ sdata->dev_attr.attr.name = sdata->name;
+ sdata->dev_attr.attr.mode = S_IRUGO;
+ sdata->dev_attr.show = show;
+}
+
+static int create_sensor_group(struct occ_sysfs *driver,
+ enum sensor_type type, int sensor_num)
+{
+ struct device *dev = driver->dev;
+ struct sensor_group *sensor_groups = driver->sensor_groups;
+ struct sensor_attr_data *sdata;
+ int rc, i;
+
+ /* each sensor has 'label' and 'input' attributes */
+ sensor_groups[type].group.attrs =
+ devm_kzalloc(dev, sizeof(struct attribute *) *
+ sensor_num * 2 + 1, GFP_KERNEL);
+ if (!sensor_groups[type].group.attrs) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ sensor_groups[type].sattr =
+ devm_kzalloc(dev, sizeof(struct sensor_attr_data) *
+ sensor_num * 2, GFP_KERNEL);
+ if (!sensor_groups[type].sattr) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ for (i = 0; i < sensor_num; i++) {
+ sdata = &sensor_groups[type].sattr[i];
+ /* hwmon attributes index starts from 1 */
+ sdata->hwmon_index = i + 1;
+ sdata->type = type;
+ sensor_attr_init(sdata, sensor_groups[type].name, "input",
+ show_input);
+ sensor_groups[type].group.attrs[i] = &sdata->dev_attr.attr;
+
+ sdata = &sensor_groups[type].sattr[i + sensor_num];
+ sdata->hwmon_index = i + 1;
+ sdata->type = type;
+ sensor_attr_init(sdata, sensor_groups[type].name, "label",
+ show_label);
+ sensor_groups[type].group.attrs[i + sensor_num] =
+ &sdata->dev_attr.attr;
+ }
+
+ rc = sysfs_create_group(&dev->kobj, &sensor_groups[type].group);
+ if (rc)
+ goto err;
+
+ return 0;
+err:
+ deinit_sensor_groups(dev, sensor_groups);
+ return rc;
+}
+
+static void caps_sensor_attr_init(struct sensor_attr_data *sdata,
+ char *attr_name, uint32_t hwmon_index,
+ uint32_t attr_id)
+{
+ sdata->type = CAPS;
+ sdata->hwmon_index = hwmon_index;
+ sdata->attr_id = attr_id;
+
+ snprintf(sdata->name, MAX_SENSOR_ATTR_LEN, "%s%d_%s",
+ "caps", sdata->hwmon_index, attr_name);
+
+ sysfs_attr_init(&sdata->dev_attr.attr);
+ sdata->dev_attr.attr.name = sdata->name;
+ sdata->dev_attr.attr.mode = S_IRUGO;
+ sdata->dev_attr.show = show_caps;
+}
+
+static int create_caps_sensor_group(struct occ_sysfs *driver, int sensor_num)
+{
+ struct device *dev = driver->dev;
+ struct sensor_group *sensor_groups = driver->sensor_groups;
+ int field_num = driver->num_caps_fields;
+ struct sensor_attr_data *sdata;
+ int i, j, rc;
+
+ sensor_groups[CAPS].group.attrs =
+ devm_kzalloc(dev, sizeof(struct attribute *) * sensor_num *
+ field_num + 1, GFP_KERNEL);
+ if (!sensor_groups[CAPS].group.attrs) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ sensor_groups[CAPS].sattr =
+ devm_kzalloc(dev, sizeof(struct sensor_attr_data) *
+ sensor_num * field_num, GFP_KERNEL);
+ if (!sensor_groups[CAPS].sattr) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ for (j = 0; j < sensor_num; ++j) {
+ for (i = 0; i < field_num; ++i) {
+ sdata = &sensor_groups[CAPS].sattr[j * field_num + i];
+ caps_sensor_attr_init(sdata,
+ driver->caps_names[i], j + 1, i);
+ sensor_groups[CAPS].group.attrs[j * field_num + i] =
+ &sdata->dev_attr.attr;
+ }
+ }
+
+ rc = sysfs_create_group(&dev->kobj, &sensor_groups[CAPS].group);
+ if (rc)
+ goto err;
+
+ return rc;
+err:
+ deinit_sensor_groups(dev, sensor_groups);
+ return rc;
+}
+
+static void occ_remove_hwmon_attrs(struct occ_sysfs *driver)
+{
+ struct device *dev = driver->dev;
+
+ device_remove_file(dev, &dev_attr_user_powercap);
+ device_remove_file(dev, &dev_attr_update_interval);
+ device_remove_file(dev, &dev_attr_name);
+}
+
+static int occ_create_hwmon_attrs(struct occ_sysfs *driver)
+{
+ int i, rc, id, sensor_num;
+ struct device *dev = driver->dev;
+ struct sensor_group *sensor_groups = driver->sensor_groups;
+ struct occ_blocks *resp = NULL;
+
+ occ_get_response_blocks(driver->occ, &resp);
+
+ for (i = 0; i < MAX_OCC_SENSOR_TYPE; ++i)
+ resp->sensor_block_id[i] = -1;
+
+ /* read sensor data from occ */
+ rc = occ_update_device(driver->occ);
+ if (rc) {
+ dev_err(dev, "cannot get occ sensor data: %d\n", rc);
+ return rc;
+ }
+ if (!resp->blocks)
+ return -ENOMEM;
+
+ rc = device_create_file(dev, &dev_attr_name);
+ if (rc)
+ goto error;
+
+ rc = device_create_file(dev, &dev_attr_update_interval);
+ if (rc)
+ goto error;
+
+ if (resp->sensor_block_id[CAPS] >= 0) {
+ /* user powercap: only for master OCC */
+ rc = device_create_file(dev, &dev_attr_user_powercap);
+ if (rc)
+ goto error;
+ }
+
+ sensor_groups[FREQ].name = "freq";
+ sensor_groups[TEMP].name = "temp";
+ sensor_groups[POWER].name = "power";
+ sensor_groups[CAPS].name = "caps";
+
+ for (i = 0; i < MAX_OCC_SENSOR_TYPE; i++) {
+ id = resp->sensor_block_id[i];
+ if (id < 0)
+ continue;
+
+ sensor_num = resp->blocks[id].header.sensor_num;
+ if (i == CAPS)
+ rc = create_caps_sensor_group(driver, sensor_num);
+ else
+ rc = create_sensor_group(driver, i, sensor_num);
+ if (rc)
+ goto error;
+ }
+
+ return 0;
+
+error:
+ dev_err(dev, "cannot create hwmon attributes: %d\n", rc);
+ occ_remove_hwmon_attrs(driver);
+ return rc;
+}
+
+static ssize_t show_occ_online(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE - 1, "%u\n", driver->occ_online);
+}
+
+static ssize_t store_occ_online(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct occ_sysfs *driver = dev_get_drvdata(dev);
+ unsigned long val;
+ int rc;
+
+ rc = kstrtoul(buf, 10, &val);
+ if (rc)
+ return rc;
+
+ if (val == 1) {
+ if (driver->occ_online)
+ return count;
+
+ driver->dev = hwmon_device_register(dev);
+ if (IS_ERR(driver->dev))
+ return PTR_ERR(driver->dev);
+
+ dev_set_drvdata(driver->dev, driver);
+
+ rc = occ_create_hwmon_attrs(driver);
+ if (rc) {
+ hwmon_device_unregister(driver->dev);
+ driver->dev = NULL;
+ return rc;
+ }
+ } else if (val == 0) {
+ if (!driver->occ_online)
+ return count;
+
+ occ_remove_hwmon_attrs(driver);
+ hwmon_device_unregister(driver->dev);
+ driver->dev = NULL;
+ } else
+ return -EINVAL;
+
+ driver->occ_online = val;
+ return count;
+}
+
+static DEVICE_ATTR(online, S_IWUSR | S_IRUGO, show_occ_online,
+ store_occ_online);
+
+struct occ_sysfs *occ_sysfs_start(struct device *dev, struct occ *occ,
+ struct occ_sysfs_config *config)
+{
+ struct occ_sysfs *hwmon = devm_kzalloc(dev, sizeof(struct occ_sysfs),
+ GFP_KERNEL);
+ int rc;
+
+ if (!hwmon)
+ return ERR_PTR(-ENOMEM);
+
+ hwmon->occ = occ;
+ hwmon->num_caps_fields = config->num_caps_fields;
+ hwmon->caps_names = config->caps_names;
+
+ dev_set_drvdata(dev, hwmon);
+
+ rc = device_create_file(dev, &dev_attr_online);
+ if (rc)
+ return ERR_PTR(rc);
+
+ return hwmon;
+}
+EXPORT_SYMBOL(occ_sysfs_start);
+
+int occ_sysfs_stop(struct device *dev, struct occ_sysfs *driver)
+{
+ if (driver->dev) {
+ occ_remove_hwmon_attrs(driver);
+ hwmon_device_unregister(driver->dev);
+ }
+
+ device_remove_file(driver->dev, &dev_attr_online);
+
+ devm_kfree(dev, driver);
+
+ return 0;
+}
+EXPORT_SYMBOL(occ_sysfs_stop);
+
+MODULE_AUTHOR("Eddie James <eajames at us.ibm.com>");
+MODULE_DESCRIPTION("OCC sysfs driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hwmon/occ/occ_sysfs.h b/drivers/hwmon/occ/occ_sysfs.h
new file mode 100644
index 0000000..2a8044f
--- /dev/null
+++ b/drivers/hwmon/occ/occ_sysfs.h
@@ -0,0 +1,52 @@
+/*
+ * occ_sysfs.h - OCC sysfs interface
+ *
+ * This file contains the data structures and function prototypes for the OCC
+ * hwmon sysfs entries.
+ *
+ * Copyright 2016 IBM Corp.
+ *
+ * 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.
+ */
+
+#ifndef __OCC_SYSFS_H__
+#define __OCC_SYSFS_H__
+
+#include "occ.h"
+
+struct sensor_group {
+ char *name;
+ struct sensor_attr_data *sattr;
+ struct attribute_group group;
+};
+
+struct occ_sysfs_config {
+ unsigned int num_caps_fields;
+ char **caps_names;
+};
+
+struct occ_sysfs {
+ struct device *dev;
+ struct occ *occ;
+
+ u16 user_powercap;
+ bool occ_online;
+ struct sensor_group sensor_groups[MAX_OCC_SENSOR_TYPE];
+ unsigned long update_interval;
+ unsigned int num_caps_fields;
+ char **caps_names;
+};
+
+struct occ_sysfs *occ_sysfs_start(struct device *dev, struct occ *occ,
+ struct occ_sysfs_config *config);
+int occ_sysfs_stop(struct device *dev, struct occ_sysfs *driver);
+
+#endif /* __OCC_SYSFS_H__ */
--
1.9.1
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