[PATCH v2] powerpc/powernv: hwmon driver for power values, fan rpm and temperature

* [PATCH v2] powerpc/powernv: hwmon driver for power values, fan rpm and temperature
@ 2014-05-19 14:38 ` Neelesh Gupta
  0 siblings, 0 replies; 18+ messages in thread
From: Neelesh Gupta @ 2014-05-19 14:26 UTC (permalink / raw)
  To: linuxppc-dev, linux, jdelvare, lm-sensors; +Cc: sbhat

This patch adds basic kernel enablement for reading power values, fan
speed rpm and temperature values on powernv platforms which will
be exported to user space through sysfs interface.

Test results:
-------------
[root@tul163p1 ~]# sensors
ibmpowernv-isa-0000
Adapter: ISA adapter
fan1:        5487 RPM  (min =    0 RPM)
fan2:        5152 RPM  (min =    0 RPM)
fan3:        5590 RPM  (min =    0 RPM)
fan4:        4963 RPM  (min =    0 RPM)
fan5:           0 RPM  (min =    0 RPM)
fan6:           0 RPM  (min =    0 RPM)
fan7:        7488 RPM  (min =    0 RPM)
fan8:        7944 RPM  (min =    0 RPM)
temp1:        +39.0°C  (high =  +0.0°C)
power1:      192.00 W  

[root@tul163p1 ~]# ls /sys/devices/platform/
alarmtimer  ibmpowernv.0  rtc-generic  serial8250  uevent
[root@tul163p1 ~]# ls /sys/devices/platform/ibmpowernv.0/
driver/    hwmon/     modalias   subsystem/ uevent     
[root@tul163p1 ~]# ls /sys/devices/platform/ibmpowernv.0/hwmon/hwmon0/
device	    fan2_min	fan4_min    fan6_min	fan8_min   power1_input
fan1_fault  fan3_fault	fan5_fault  fan7_fault	in1_fault  subsystem
fan1_input  fan3_input	fan5_input  fan7_input	in2_fault  temp1_input
fan1_min    fan3_min	fan5_min    fan7_min	in3_fault  temp1_max
fan2_fault  fan4_fault	fan6_fault  fan8_fault	in4_fault  uevent
fan2_input  fan4_input	fan6_input  fan8_input	name
[root@tul163p1 ~]# 
[root@tul163p1 ~]# ls /sys/class/hwmon/hwmon0/
device	    fan2_min	fan4_min    fan6_min	fan8_min   power1_input
fan1_fault  fan3_fault	fan5_fault  fan7_fault	in1_fault  subsystem
fan1_input  fan3_input	fan5_input  fan7_input	in2_fault  temp1_input
fan1_min    fan3_min	fan5_min    fan7_min	in3_fault  temp1_max
fan2_fault  fan4_fault	fan6_fault  fan8_fault	in4_fault  uevent
fan2_input  fan4_input	fan6_input  fan8_input	name
[root@tul163p1 ~]#

Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
---

Changes in v2
=============
- Generic use of devm_* functions in hwmon like using devm_kzalloc() for dynamic
  memory request, avoiding the need to explicit free of memory.
  Adding 'struct attribute_group' as member of platform data structure to be
  populated and then passed to devm_hwmon_device_register_with_groups().

  Note: Having an array of pointers of 'attribute_group' and each group
  corresponds to 'enum sensors' type. Not completely sure, if it's ideal or
  could have just one group populated with attributes of sensor types?

- 'ibmpowernv' is not hot-pluggable device so moving 'platform_driver' callback
  function (probe) as part of __init code.
- Fixed issues related to coding style.
- Other general comments in v1.

 drivers/hwmon/Kconfig      |    8 +
 drivers/hwmon/Makefile     |    1 
 drivers/hwmon/ibmpowernv.c |  368 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 377 insertions(+)
 create mode 100644 drivers/hwmon/ibmpowernv.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index bc196f4..3e308fa 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -554,6 +554,14 @@ 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 platform.
+
 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 c48f987..199c401 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 0000000..afce620
--- /dev/null
+++ b/drivers/hwmon/ibmpowernv.c
@@ -0,0 +1,368 @@
+/*
+ * IBM PowerNV platform sensors for temperature/fan/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.
+ */
+
+#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 DRVNAME		"ibmpowernv"
+#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", {0}, 0},
+	{"temp", "ibm,opal-sensor-amb-temp", {0}, 0},
+	{"in", "ibm,opal-sensor-power-supply", {0}, 0},
+	{"power", "ibm,opal-sensor-power", {0}, 0}
+};
+
+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) {
+		pr_err("%s: Failed to get opal sensor data\n", __func__);
+		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, "%d\n", x);
+}
+
+static void __init get_sensor_index_attr(const char *name, u32 *index, char *attr)
+{
+	char *hash_pos = strchr(name, '#');
+	char *dash_pos;
+	u32 copy_len;
+	char buf[8];
+
+	memset(buf, 0, sizeof(buf));
+	*index = 0;
+	*attr = '\0';
+
+	if (hash_pos) {
+		dash_pos = strchr(hash_pos, '-');
+		if (dash_pos) {
+			copy_len = dash_pos - hash_pos - 1;
+			if (copy_len < sizeof(buf)) {
+				strncpy(buf, hash_pos + 1, copy_len);
+				sscanf(buf, "%d", index);
+			}
+
+			strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
+		}
+	}
+}
+
+/*
+ * 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(enum sensors type, const char *node_name,
+				  char *hwmon_attr_name)
+{
+	char attr_suffix[MAX_ATTR_LEN];
+	char *attr_name;
+	u32 index;
+
+	get_sensor_index_attr(node_name, &index, attr_suffix);
+	if (!index || !strlen(attr_suffix)) {
+		pr_info("%s: Sensor device node name is invalid, name: %s\n",
+				__func__, node_name);
+		return -EINVAL;
+	}
+
+	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;
+	int err = 0;
+
+	opal = of_find_node_by_path("/ibm,opal/sensors");
+        if (!opal) {
+		pr_err("%s: Opal 'sensors' node not found\n", __func__);
+		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;
+			}
+	}
+
+	for (type = 0; type < MAX_SENSOR_TYPE; type++) {
+		if (!sensor_groups[type].attr_count)
+			continue;
+
+		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) {
+			pr_err("%s: Failed to allocate memory for attribute"
+					"array\n", __func__);
+			err = -ENOMEM;
+			goto exit_put_node;
+		}
+
+		pgroups[type] = &sensor_groups[type].group;
+		pdata->sensors_count += sensor_groups[type].attr_count;
+		sensor_groups[type].attr_count = 0;
+	}
+
+exit_put_node:
+	of_node_put(opal);
+	return err;
+}
+
+/*
+ * Iterate through the device tree for each child of sensor 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 u32 *sensor_id;
+	enum sensors type;
+	u32 count = 0;
+	int err = 0;
+
+	opal = of_find_node_by_path("/ibm,opal/sensors");
+        if (!opal) {
+		pr_err("%s: Opal 'sensors' node not found\n", __func__);
+		return -ENODEV;
+        }
+
+	sdata = devm_kzalloc(&pdev->dev, (pdata->sensors_count) *
+			     sizeof(*sdata), GFP_KERNEL);
+	if (!sdata) {
+		pr_err("%s: Failed to allocate memory for the sensor_data",
+				__func__);
+		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) {
+			pr_info("%s: %s doesn't have sensor-id\n", __func__,
+				np->name);
+			continue;
+		}
+
+		sdata[count].id = *sensor_id;
+		sdata[count].type = type;
+		err = create_hwmon_attr_name(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 file 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("%s: Device allocation failed\n", __func__);
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	err = platform_device_add(pdevice);
+	if (err) {
+		pr_err("%s: Device addition failed (%d)\n", __func__, err);
+		goto exit_device_put;
+	}
+
+	err = platform_driver_probe(&ibmpowernv_driver, ibmpowernv_probe);
+	if (err) {
+		pr_err("%s: Platfrom driver probe failed\n", __func__);
+		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);

^ permalink raw reply related	[flat|nested] 18+ messages in thread